Plaintiff v First Defendant

Introduction and overview: impairment assessments under the Wrongs Act 1958 for spinal injuries that have been operated on

1 This is an application for judicial review under Order 56 of the Supreme Court (General Civil Procedure Rules) 2015 of a determination make by a Medical Panel under Part VBA of the Wrongs Act 1958 ('the Act').[1]

2 The effect of Part VBA of the Act[2] is that a person is not entitled to recover common law damages for non-economic loss in respect of personal or bodily injury caused by the fault of another person unless the person has suffered 'significant injury' as defined. So far as presently relevant, an injury will be 'significant' if the degree of impairment of the whole person resulting from the injury has been assessed in accordance with Part VBA as satisfying the 'threshold level' specified in Part VBA for the particular kind of injury. Generally speaking, an assessment will only be in accordance with Part VBA if it is made in accordance with the American Medical Association's Guides to the Evaluation of Permanent Impairment (4th edition) ('the AMA Guides').

3 It is only permanent impairment that falls to be assessed under Part VBA and the AMA Guides. Accordingly, the assessor is usually required to take into account the effects of any surgery or other treatment undertaken by the injured person in respect of the injury.[3] However, a major issue in the present case is whether, or to what extent, the situation is different for spinal injuries. Of central importance is a particular paragraph relating to spinal surgery which is contained in the AMA Guides.

4 The plaintiff claims that she suffered spinal injuries in a fall caused, she says, by the fault of the first defendant. She later underwent spinal surgery. The purpose of the surgery, at least in large part, was to treat her claimed spinal injuries. The Medical Panel determined that the claimed injuries did not satisfy the threshold level. The plaintiff now presses two complaints about the Panel's determination.

5 First, the plaintiff says that, because of the abovementioned paragraph in the AMA Guides, the Panel was required to assess the degree of impairment resulting from all of her claimed spinal injuries as those injuries stood before the surgery; and she asserts that the Panel simply omitted to do so in relation to certain of her claimed spinal injuries.

6 Secondly, the plaintiff says that the Panel should also have included in the assessment an evaluation of the degree of impairment resulting from injuries to her spine which, she claims, were involved in or caused by the spinal surgery itself. According to the plaintiff, the Panel wrongly considered itself precluded from doing so by reason of the paragraph in question in the AMA Guides.

7 These complaints fall to be determined partly as a matter of interpretation of the Panel's statement of reasons, partly as a matter of interpretation of Part VBA (which has seven Divisions and is comprised of sections 28LB to 28LZU inclusive) of the Act, and partly as matter of interpretation of the AMA Guides (particularly the section relating to the spine), all read in the light of relevant authority, especially the judgment of the Court of Appeal in Mountain Pine Furniture Pty Ltd v Taylor.[4]

8 In 2009, in HJ Heinz Company Australia Ltd v Kotzman ('HJ Heinz'),[5] Kyrou J (as his Honour then was) summarised, with reference to relevant authorities, the general principles for interpreting and applying the AMA Guides in the context of the Accident Compensation Act 1985 ('AC Act'). In 2012, his Honour's summary of the general principles was quoted with approval by Bongiorno JA and John Dixon AJA in Victorian Workcover Authority v Elsdon,[6] also a case under the AC Act. In HJ Heinz, in a later part of his judgment,[7] Kyrou J had elaborated on the general principles insofar as they related to the requirement in s 91 of the AC Act that an impairment assessment be conducted 'in accordance with the AMA Guides'.[8] In 2013, in Saddington v Kotzman,[9] Kyrou J added this elaboration to his Honour's catalogue of general principles, and said that the general principles were equally applicable to Part VBA of the (Wrongs) Act. His Honour proceeded to restate the general principles in the context of the (Wrongs) Act, as follows:[10]

22 The interpretation of the Guides is a question of law.[11] The determination of a degree of impairment is a question of fact.[12]

23 It has been said that to the extent that an Act requires determinations of impairment to be made in accordance with the Guides, the Guides has the force of law[13] and is a legislative document.[14]

24 However, the Guides is, as its title suggests, a guide.[15] It was written by expert medical practitioners and not by statutory draftspeople, and should not be overlaid with legalistic - or a lawyer's precise - interpretation.[16] It is of paramount importance to be faithful to the Guides' plain words.[17] The Guides should not be interpreted as if it were a statute.[18]

25 The use of the Guides is designed to promote precision, certainty and consistency.[19] Its purpose is to make as objective as possible the process of estimating impairment by reference to sufficient medical and non-medical information to justify the estimate.[20]

26 If there is any inconsistency between the Act and the Guides, the Act will prevail. If there is any inconsistency between the text in the Guides and an example which seeks to illustrate what is said in the text, the text will prevail.[21]

27 The meaning of the phrase 'in accordance with' depends on the context. It is generally taken to mean 'in conformity with', although in some contexts, strict compliance is not required.[22]

28 In order for a medical panel to assess impairment 'in accordance with' the Guides as required by ss 28LZG(1) and 28LH(1)(a) of the Act, it must act in conformity with the Guides. This means that it must apply the methodologies, processes and criteria set out in the Guides for the relevant condition, body part or system and adhere to any minimum or maximum values set out in the Guides for that condition, body part or system. Where the Guides contains a table that is applicable to a condition, body part or system, an assessment based on that table will not be in accordance with the Guides unless the categories, descriptions, criteria, ranges, adjustments and other elements of the table that are relevant to the condition, body part or system are adhered to and complied with.

29 Once a particular methodology or table is selected, its requirements, including any limitations, must be applied in the manner set out by the Guides even if the outcome may appear sub-optimal. This is so because the role conferred by the Act on a medical panel is not to arrive at a correct or fair assessment, but rather to arrive at an assessment that is the product of the application of the Guides.

I gratefully adopt this restatement of the general principles for interpreting and applying the AMA Guides in relation to Part VBA of the Act.

9 The paragraph in question in the AMA Guides appears in Chapter Three (The Musculoskeletal System), section 3.3 (The Spine), at page 3/100. The paragraph has been referred to in certain authorities as a 'direction'.[23] It reads:

With the Injury Model, surgery to treat an impairment does not modify the original impairment estimate, which remains the same in spite of any changes in signs or symptoms that may follow the surgery and irrespective of whether the patient has a favorable or unfavorable response to treatment.

10 The Injury Model, mentioned at the beginning of the 'direction', is also called the Diagnosis-Related Estimates ('DRE') Model. It is referred to in section 3.3 as an 'approach' to evaluating spine impairments and it is set out in detail in that section.[24] It was new to the 4th edition of the AMA Guides. It is said to apply especially to patients' traumatic injuries. It involves 'assigning a patient to one of eight categories, such as minor injury, radiculopathy, loss of spine structure integrity, or paraplegia, on the basis of objective clinical findings'.[25]

11 Section 3.3 of the AMA Guides also provides for the use of another approach, called the Range of Motion Model, as an alternative. This Model (also referred to as the Functional Model) had been the only approach provided for in the corresponding sections of previous editions of the AMA Guides. The Range of Motion Model is 'based on assessing the degree of spine motion and assigning impairment percents according to limitations of motion. Impairment percents related to the range of motion [are] to be combined with percents based on diagnoses or therapeutic approaches and neurologic impairments'.[26]

12 With the Injury Model, 'the main spine regions are termed the cervicothoracic, thoracolumbar, and lumbosacral regions'.[27] With the Range of Motion Model, 'the main regions are called the cervical, thoracic and lumbar regions'.[28]

13 The AMA Guides say that the evaluator assessing the spine should use the Injury Model if the patient's condition is one of those listed in Table 70 in section 3.3. If none of the eight categories of the Injury Model is applicable, then the evaluator is instructed to use the Range of Motion Model.[29] However, if when using the Injury Model the assessor cannot decide into which of the eight categories the patient belongs, the assessor may make an estimate under the Range of Motion Model and then use that estimate to decide placement within one of the Injury Model categories.[30]

14 Where multiple spinal regions are impaired, under the Injury Model, the evaluator first selects the region of the spine that is primarily involved and determines an impairment value using the table referring to that region. Then the evaluator determines the impairment of the other region(s) and combines the regional impairments using a Combined Values Chart.[31]

15 The relevant terms of the AMA Guides, especially the terms relating to the Injury Model in section 3.3, are summarised at greater length in the decisions at first instance and on appeal in the Mountain Pine litigation.[32]

The plaintiff's claim and the Medical Panel's decision

16 The plaintiff, Ms Hart, wishes to claim damages for non-economic loss against the first defendant, Melbourne Underwater World Pty Ltd ('MUW'), which conducted an aquarium. The plaintiff intends to allege that she injured her spine in a fall on some stairs at MUW's aquarium in April 2012; and that negligence or other fault on the part of MUW was a cause of her spinal injuries and related injuries. It is common ground that she is therefore a 'claimant' within the meaning of Part VBA of the Act, a term defined in s 28LB as 'a person who makes or is entitled to make a claim for damages that relate to the injury to a person caused by the fault of another person'. Ms Hart has not yet actually commenced any common law proceedings against MUW.

17 Ms Hart was born in 1944. She has a long and extensive medical history. It includes, among numerous other things, low back problems. According to what Ms Hart told the Medical Panel, her low back problems began in 1987, after she carried a suitcase up a narrow spiral staircase. She had surgery by two orthopaedic surgeons at that time, probably at the left L5/S1 level. A year later she was involved in a motor vehicle accident causing further low back related symptoms. She had several spinal operations by a third orthopaedic surgeon resulting in her having a fusion from L3 to the S1 level (L3/4, L4/5, and L5/S1). Her lower back pain had gradually settled and she had returned to part-time work in the early 1990's. She had retired from work in about 2009 due to a cardiac condition. However, her low back was never totally pain free between her last surgical procedure in the 1990's and the incident in April 2012. In the five years before the incident she had continued to have mild low back pain and pain in both her left lower limb and her right calf.

18 At the time of the alleged fall, Ms Hart was 67 years of age. She saw various medical practitioners about the alleged consequences of the fall. By 2013 she had instructed solicitors. In February 2014 she was examined by Mr Peter Kudelka, an orthopaedic surgeon. Mr Kudelka diagnosed pain from aggravation of degenerative changes in parts of the lumbo-sacral spine that had previously been operated on. He issued a certificate of assessment under Part VBA of the Act to the effect that the degree of impairment resulting from Ms Hart's injuries from the alleged fall was more than 5 per cent. Such a degree of impairment satisfied the threshold level for spinal injury as it then stood.[33] On 25 March 2014 Ms Hart's solicitors served Mr Kudelka's certificate on MUW, together with the prescribed particulars of her claim pursuant to s 28LT of the Act and the relevant Regulations. At that stage, Ms Hart had not undergone any surgery for her alleged 2012 injuries. So, of course, the particulars made no reference to any such surgery. It appears that, pursuant to s 28LW(2)(b) of the Act, MUW responded to the receipt of the certificate of assessment by stating that it was a proper respondent to the claim and by advising that it intended to refer, or had referred, a medical question in relation to the assessment to a Medical Panel for determination under Part VBA.[34]

19 In any event, on 14 May 2014 MUW, acting under s 28LWE of the Act, referred a medical question for determination by a Medical Panel. It was a medical question of the only kind for which Part VBA provides. The question was: 'Does the degree of impairment resulting from the physical injury to the claimant alleged in the claim satisfy the threshold level?' However, the referral was put on hold, apparently because Ms Hart had decided, on advice from two neurosurgeons (Associate Professor Danks and Mr Tony Goldschlager), to undergo yet another operation on her spine.[35] The neurosurgeons noted that at L2/3 and L1/2 there were broad-based disc bulges and a significant degree of canal stenosis. They considered that these things were the main causes of Ms Hart's problems. In a pre-operative report, Mr Goldschlager named her relevant condition as neurogenic claudication. He proposed treatment by way of surgery, through a 'posterior decompression instrumented fusion'. He continued: 'I would not like to stop the fusion at the thoracolumbar junction due to the risk of proximal junction kyphosis and adjacent segment disease, and I would therefore likely take the fusion to the T10 or T11 level'. The operation was duly performed by Mr Goldschlager on 19 July 2014. It included laminectomies at three levels and fusions at four levels of the plaintiff's spine. As foreshadowed by Mr Goldschlager, two of the four fusions were done at levels T11/12 and T12/L1, being levels higher than the perceived sites of the plaintiff's pain-producing spinal problems. There is no suggestion of negligent surgery or of any proposed claim against any person or entity involved in the surgery.

20 Importantly, there is no suggestion, either, that the laminectomies or the fusions or any other part of the surgery went wrong in any way, or caused any changes to the plaintiff's spine other than the very changes intended by the surgeon, being changes that were part and parcel of the surgery.

21 In 2016, the referral to the Medical Panel was revived. Two medical practitioners were appointed to constitute the Panel. (They comprise the third defendant in this case.) Ms Hart and MUW were each represented by solicitors at that time. Unfortunately, however, Ms Hart's formal particulars of claim were not updated by reference to the 2014 surgery or otherwise. Nevertheless, in the course of the referral, the Panel sought, by letter, comment from both sets of solicitors as to whether the Panel was able to take into account the two fusions that had been done, at least in part, for precautionary or preventative reasons at the higher spinal levels. In particular, the Panel enquired as to whether those two fusions could be treated as further injuries, additional to any injuries that had been suffered in the fall. It was implicit in the Medical Panel's enquiry that it considered itself precluded from taking into account the other elements of the surgery, i.e. the lower level fusions and laminectomies, or their effects, in any event. The implicit assumption seems to have been that the lower level fusions and laminectomies, at least, had to be disregarded, as a matter of law, because they were done by way of treatment of the original (2012) claimed injuries. That assumption, in turn, was clearly tied to the 'direction' in the AMA Guides, which the Medical Panel quoted in its letters and which it quoted again, later, in its statement of reasons for the determination.[36] The 'direction' had previously been considered in detail, in the context of the AC Act, in the decision of the Victorian Court of Appeal in Mountain Pine Furniture Pty ltd v Taylor[37] (discussed below) of which the Panel was no doubt aware.

22 The written responses by the solicitors for the respective parties to the Panel were apparently based on the same assumption as had been implicit in the letters from the Panel. However, the plaintiff's solicitors did submit to the Panel that the two higher level fusions could and should be taken into account as further injuries. On the other hand, the solicitors for MUW submitted to the Panel that the two fusions represented 'changes in signs and symptoms following the claimant's "surgery to treat an impairment"' rather than 'a new and distinct impairment that may be assessed separately from the original impairment'. They submitted that, pursuant to the paragraph in question in the AMA Guides, surgery to treat an impairment is simply to be disregarded entirely. They further submitted that proximal junction kyphosis was a well recognised complication of fusion surgery and that it would be entirely artificial to attempt to create a distinction between stages of the same surgery.

23 It is clear from the Medical Panel's letters to the solicitors and from its statement of reasons (see below) that the Panel regarded the two higher level fusions as being included in the injuries alleged in the claim. As senior counsel for MUW later said in the hearing before me,[38] this was a proper approach for the Panel to take because the two higher level fusions were mentioned in medical reports that were before the Panel and because cases in this Court have indicated that Medical Panels should take a broad, non-technical view of what is included in a claimant's claim.[39] However, as indicated below, the Panel's ultimate conclusion on this aspect was that, by virtue of the 'direction' at page 100 of the AMA Guides, the Panel was 'precluded from assessing any additional thoracolumbar spine impairment resulting from the injury to the Claimant alleged in the claim'.

24 In the end, the Panel determined that the degree of impairment of the plaintiff did not satisfy the threshold level. If the Panel's determination stands, the plaintiff will be prevented from bringing her proposed proceedings against MUW.[40]

25 In its statement of reasons, after the formal parts, the Medical Panel noted that the alleged physical injuries in the (March 2014) claim were described as:

• aggravation of previous degenerative changes in the lumbosacral spine;

• pain to lower back below the waistline, groin and lower back side (sic);

26 Next, the Panel recorded the history given by the plaintiff, including her accounts of the alleged incident, her prior and subsequent medical history and her current symptoms and treatment.

27 In the next section of its reasons, the Panel described its findings on examination and on the review of available CT scans and other medical imaging.

The Panel considered no additional medical imaging or other investigations were necessary for it to assess the claimant's current condition and impairment.

The Panel noted from the referral that claimed injuries resulting from the incident are to the lumbosacral spine. The Panel noted the treatment of the alleged physical injury had resulted in loss of function in both the lumbosacral and thoracolumbar sections of her spine.

The Panel concluded the claimant is suffering from thoracolumbar spinal dysfunction and lumbosacral spinal dysfunction with a left S1 radiculopathy. The Panel considers the claimant's condition has stabilised.

The Panel conducted an impairment assessment according to the methods prescribed in the American Medical Association Guides to the Evaluation of Permanent Impairment (4th Edition-3rd printing), as required by Section 28LH of the Wrongs Act 1958. The Panel considered that no further information was required from the Claimant's treating practitioners to carry out the assessment.

The Panel noted that the following paragraph is included on page 100 of Chapter Three of the Guides:

"With the Injury Model, surgery to treat an impairment does not modify the original impairment estimate, which remains the same in spite of any changes in signs or symptoms that may follow the surgery and irrespective of whether the patient has a favourable or unfavourable response to treatment" (the direction)

The Panel noted from the referral that, as a result of the incident, the claimant alleges she suffered injury described as: "aggravation of previous degenerative changes in the lumbosacral spine; pain to the lower back below the waist line, groin and lower back side. Pain radiates down the left leg to the foot; numbness experiences (sic) in the toes; 3 x disc prolapsed and spinal stenosis."

The Certificate of Assessment prepared by Mr Peter Kudelka dated 29 February 2014 describes the injury assessed as: "Aggravated lumbosacral pain from previous spinal surgery."

The Panel noted the report of A/Prof Andrew Danks dated 28 May 2014 wherein it is stated that "the CT scan shows solid fusions at L3/4, L4/5 and L5/S1 and acceptable decompressions at those levels. On the left side at L5/S1, there are some changes in the left lateral recess which are probably just artefact, but are a bit unclear. At L2/3 and L/1/2 there are broad-based disc bulges and a significant degree of canal stenosis. I think that these levels might well be the principle [sic] culprit in Lynda's condition."

Mr Tony Goldschlager's report dated 10 June 2014 identifies "significant" at L2/3 and "fairly significant" canal stenosis at L1/2, and states, "I feel (as did Professor Danks) that this is the cause of her problem and I feel that she has neurogenic claudication due to the severity of this canal stenosis. I have discussed the treatment options with her and she has elected for surgery, which I would perform through a posterior decompression instrumented fusion. I would not like to stop the fusion at the thoracolumbar junction due to the risk of proximal junction kyphosis and adjacent segment disease, and I would therefore likely take the fusion to the T10 or T11 level."

The Panel noted that the operation report dated 19 July 2014 indicates "laminectomies were then performed from T12 - L3 inclusive."

The Deputy Convenor of Medical Panels wrote to the parties on behalf of the Panel on the 1 April 2016, outlining the above matters and requesting submissions "as to whether the fusions at T11/12 and T12/L1 undertaken at the operation on 19 July 2014 are changes in 'signs or symptoms' following surgery and therefore precluded from consideration of the 'original impairment estimate' as per the direction in the Guides at page 3/100 or whether the fusions to the thoracolumbar spine constitute further injury which might be assessed separately to the 'original impairment estimate' concerning the lumbosacral spine."

The Panel noted the submissions on behalf of the Claimant and Respondent, respectively dated 15 April 2016 and 19 April 2016.

The claimant submits, interalia, that the Claimant's ""impairment" should be defined as the canal stenosis at the L2/3 and L1/2 levels, as stated by Mr. Goldschlager and Professor Danks.

If the fusion to the extended levels (T11/12 and T12/L1) has resulted in further impairment, we submit that the fusions constitute a further injury which should be assessed separately."

The respondent submits, interalia, that "the fusions at T12 - L1 represent changes in signs and symptoms following the Claimant's 'surgery to treat an impairment', and as such are to be disregarded for the purpose of the Claimant's assessment."

The Panel assessed the impairment of the back in accordance with the Specific Procedure and Directions in Section 3.3f on page 101 of the Guides.

The Panel assessed the appropriate whole person impairment attributable to the Claimant's lumbosacral spine, pre-surgery 19 July 2014, in accordance with Tables 70 & 72 of Chapter Three.

As the Panel was able to assess the lumbosacral impairment in accordance with the Diagnosis-related Estimates (DRE) method of impairment assessment, use of the Range of Motion method of impairment assessment was considered inappropriate.

The Panel also assessed the appropriate whole person impairment for the surgical scarring in accordance with Table 2 of Section 13.5 of Chapter Thirteen of the Guides.

The Panel, noting the direction at page 100 of the Guides, considers that it is precluded from assessing any additional thoracolumbar spine impairment resulting from the injury to the Claimant alleged in the claim.

In making an assessment of impairment, the Panel took into account the claimant's history and the referral material to determine the level of impairment that may have been present prior to the incident on 11 April 2012 and which the Panel ought to disregard in accordance with Section 28LL(3) of the Wrongs Act as impairment from unrelated causes or injuries.

In considering its obligation to disregard unrelated impairment, the Panel noted the decision in Wilson v Liquorland Australia Pty Ltd [2014] VSC 545 wherein the Court emphasized the need for an "evidentiary basis by which the Panel could derive a positive satisfaction of a pre-existing impairment."

The Panel noted the claimant has a significant past history in relation to her lumbosacral spine including an L5/S1 laminectomy and a spinal fusion from L3 to S1. The Panel noted she had an absent left ankle jerk consistent with a left S1 radiculopathy (treated by laminectomy at L5/S1). The Panel noted her recent treatment was from T11 to L3 and did not include the left S1 nerve root. Based on the medical imaging, the above history and available documentation, the Panel concluded that there is evidence of impairment of the claimant's lumbar spine from an unrelated injury or cause which is playing a part in the claimant's current impairment which ought to be disregarded in accordance with Section 28LL(3) of the Act.

The Panel gave consideration to the Court of Appeal judgment in the case of Lingenberg -v- Gallichio & Ors [14 June 2013], in which the Court states that "the statutory imperative to disregard the degree of impairment due to underlying injury requires a Medical panel to 'do its best to evaluate the extent to which impairment from the unrelated injury or cause is playing a part in the (Claimant's) current impairment.'"

After disregarding that part of the Claimant's impairment which arises from unrelated injuries or causes, pursuant to Section 28LL(3) of the Wrongs Act 1958, the Panel concluded that the degree of impairment resulting from the spinal injury to the claimant alleged in the claim is permanent but is not 5% or more and therefore does not satisfy the threshold level as prescribed by Section 28LB of the Act as amended.

After combining the whole person impairments attributable to the spinal injury and/or surgical scarring in accordance with the formula prescribed at page 322 of the Guides, the Panel concluded that the degree of whole person impairment resulting from the spinal injury and/or the physical injuries to the Claimant alleged in the claim is permanent, but is not more than 5%.

The Panel considered it has assessed all potentially compensable injuries in accordance with the Guides and by operation of Section 28LZG(4) of the Act, it is precluded from further explanation or detailed reasons of the basis on which it has calculated impairment in accordance with the Guides.

The Panel also considers it is not required to make a finding in relation to the issue of whether or not the claimant's current impairment which the claimant attributes to the injuries alleged in the claim, was caused by the circumstances of the incident, as alleged, that gave rise to the claim but the Panel has assessed impairment only arising from the injuries to the claimant that are potentially compensable.

29 The plaintiff's originating motion for judicial review is an extraordinarily lengthy and convoluted document. However, even so, it did not cover the matter described above as the first complaint which the plaintiff now makes against the Medical Panel's determination. This complaint was first raised in the plaintiff's written submissions in reply filed shortly before the hearing.[41] MUW did not object to the late raising of the complaint and went on to deal with it in its oral submissions.[42] As indicated above, this first complaint was to the effect that the Panel simply omitted to consider what the plaintiff now says was the most important of her claimed pre-surgery injuries, namely the state of her spine at levels L1/2 and L2/3 as it was before the surgery.

30 By contrast, the plaintiff's second complaint was, in large part, covered by her originating motion. In that document,[43] and in the plaintiff's written submissions in reply,[44] she alleged that the Panel erred in law by excluding the two higher level fusions from its assessment. In oral submissions, the plaintiff expanded this allegation by submitting, in effect, that the Panel would have been required to take into account other parts of the surgery as well had she asserted in her proposed claim (which she did not) that those other parts of the surgery involved or produced a further injury or injuries. Her senior counsel indicated that, on any remittal, the plaintiff would add those other parts of the surgery to her claim.[45]

31 Otherwise, the plaintiff abandoned[46] all of the multifarious points contained in her originating motion and in her initial set of written submissions.[47]

Resolving the plaintiff's first complaint: Did the Panel omit to consider claimed pre-surgery injuries?

32 The plaintiff contends that the Medical Panel omitted altogether to consider and assess the pre-surgery condition of her spine at the levels of L1/2 and L2/3.[48] She submits that the state of her spine at those levels comprised the main part of her claim in relation to her pre-injury condition. She points out that her problems at those spinal levels had been referred to in the reports of Associate Professor Danks and Mr Goldschlager, which were included in the documents before the Medical Panel. She points out also that significant stenosis at L2/3, and slightly less at L1/2, had been mentioned in the medical reports; and that the formal particulars of claim had referred to three disc prolapses and to spinal stenosis.

33 The plaintiff's contention that these matters had not been considered by the Panel is based in large part on the circumstance that the Panel said in its reasons that it was assessing the pre-surgery condition of the plaintiff's lumbosacral spine.[49] For example, the Panel said in its reasons that (i) it noted from the referral that the claimed injuries resulting from the incident were to the 'lumbosacral' spine; (ii) that it had assessed the plaintiff's whole person impairment attributable to her 'lumbosacral spine, pre-surgery 19 July 2014...'; and (iii) that it was able to assess the 'lumbosacral' impairment in accordance with the DRE method (the Injury Model). According to the plaintiff, under the Injury Model the spinal levels of L1/2 and L2/3 do not form part of the lumbosacral region but rather of the thoracolumbar region. In addition, the plaintiff submits,[50] it is surprising that the Panel did not assess the plaintiff's pre-surgical impairment as satisfying the then (and now) applicable threshold level (5 per cent or more), having regard to the dire picture of the pre-surgical condition of her spine at L1/2 and L2/3 as painted by Associate Professor Danks and Mr Goldschlager in particular. The inference to be drawn, she submits,[51] is that the Panel simply omitted to take into account her pre-surgery problems at L1/2 and L2/3.

34 As mentioned above, these arguments were only raised belatedly. Further, senior counsel for the plaintiff advanced them at the hearing with what seemed to be fluctuating degrees of enthusiasm. At a late stage of the hearing, he appeared to resile from them completely, submitting that, if the determination of the Medical Panel were to be set aside and the matter remitted for redetermination, the re-assessment required would not be an assessment of the plaintiff's condition as it was pre-surgery but rather as it was post-surgery, in all respects.[52] Senior counsel then seemed to depart from this as well,[53] and in the end he did not dissent from my indication at the very end of the hearing that I understood this point to amount to an assertion that the Medical Panel simply omitted to assess the condition of the plaintiff's spine at L1/2 and L2/3 as it was pre-surgery.

35 Even though the plaintiff's first complaint seems not to amount to a complaint of error of law, I would assume in her favour, without deciding, that if, as a matter of fact, her complaint were made out, it would follow that the Medical Panel had made a jurisdictional error. The kind or category of jurisdictional error might be failing to deal with a claim, or an integer of a claim, made by a party.[54] However, the burden of establishing that the Medical Panel erred rests on the plaintiff. It is not sufficient to demonstrate a possibility of error to discharge that burden.[55] Far from being persuaded that the Panel made the error alleged, I am positively satisfied that it did not.

36 My reasons in this regard are substantially in accord with the answers given by MUW to the plaintiff's first complaint.[56] They may be divided into four parts, as follows.

37 First, on a proper reading of Chapter Three of the AMA Guides as a whole, and of page 95 in particular, it is not correct to say that, for the purposes of the Injury Model, spinal levels L1/2 and L2/3 are not included within the lumbosacral region. The AMA guides do not say that. Nor do the AMA Guides say that L1/2 and L2/3 are included in the thoracolumbar region. To the contrary, it is clear from the text at p 95 that the 'main regions' of the spine are the same under both Models. They merely have different titles for the purposes of the respective Models. Thus, the AMA Guides state at the foot of p 95:

For the purposes of this book, the cervical region may be considered to represent the cervicothoracic region, the thoracic region to represent the thoracolumbar region, and the lumbar region to represent the lumbosacral region.

The plaintiff does not suggest that the L1/2 level or the L2/3 level is not included in the 'lumbar region' for the purposes of the Range of Motion Model. Nor does the plaintiff specify a particular level where, on her argument, the thoracolumbar region ends and the lumbosacral region begins for the purposes of the Injury Model. [57] That is to say, the plaintiff does not specify a particular level different from the level (T12/L1) that separates the thoracic region from the lumbar region for the purposes of the Range of Motion model and for all other ordinary medical purposes. As already indicated, the AMA Guides themselves certainly do not specify any such different level. I accept MUW's submission[58] that the terminology of cervicothoracic, thoracolumbar and lumbosacral has been adopted for the purposes of the Injury Model merely in order to assist the medical assessor to better identify the anatomical distribution of sources of pain being complained of by the patient. That submission is borne out by the language of the AMA Guides, especially at p 95.

38 It might be said that the present issue is whether, in the AMA Guides, the expressions 'cervicothoracic', 'thoracolumbar', and 'lumbosacral' do or do not have specialised meanings for the purposes of the Injury Model and, if so, what any such specialised meaning is. If that is a proper characterisation of the issue arising, then it is an issue on which the Court may refer to authoritative medical texts or relevant expert evidence.[59] For the reasons about to be mentioned as the second, third and fourth responses to the plaintiff's first complaint, it is evident to me that the Medical Panel understood the AMA Guides to treat the spinal levels L1/2 and L2/3 as being part of the lumbosacral spine, as distinct from the thoracolumbar spine, for the purposes of the Injury Model. The Panel is an expert body comprised of medical practitioners. The AMA Guides were written by medical practitioners, for use by medical practitioners, for the purpose of making a medical assessment.[60] The fact that the Medical Panel read the Guides in the way it did in the present respect gives me some degree of further comfort that my own reading of the AMA Guides in this respect is a correct reading. There is additional support for this reading in what I regard as an authoritative text.[61] However, my own reading would be the same in any event.

39 Secondly, it is inherently very unlikely that any Medical Panel would simply overlook injuries or impairments on which a claimant prominently relied.

40 Thirdly, this particular Panel's reasons show that it was well aware of, and considered, the pre-surgery condition of Ms Hart's spine at the L1/2 and L2/3 levels and her claims in that regard. Towards the beginning of its statement of reasons, in listing the alleged physical injuries as described in the claim, the Panel expressly included 'three x disc prolapsed and spinal stenosis'. Later, the Panel noted that Ms Hart's solicitors had submitted that her 'impairment should be defined as the canal stenosis at the L2/3 and L1/2, as stated by Mr Goldschlager and Professor Danks'. The Panel actually quoted, and otherwise referred to, the critical parts of the reports of Associate Professor Danks and of Mr Goldschlager, including the reference in the former to L1/2 and L2/3 being likely to be the principal 'culprits' in Ms Hart's condition, and the reference in the latter to Mr Goldschlager's concurrence with this. Shortly after that, the Panel said that it had assessed the whole person impairment attributable to Ms Hart's lumbosacral spine 'pre-surgery 19 July 2014'. The reference to 'pre-surgery 19 July 2014' points directly to the particular spinal condition that was, as the Panel was plainly aware, the prime focus of the surgery, namely, the condition of levels L1/2 and L2/3 of Ms Hart's spine.

41 Fourthly, there is no substance in the plaintiff's argument to the effect that the best explanation for the Medical Panel's ultimate determination against her is that it simply overlooked this part of her claim. The plaintiff has not advanced, or at least no longer maintains, any ground of review to the effect that the determination of the Panel was legally unreasonable.[62] At least in the absence of a request under s 8 of the Administrative Law Act 1978, the Panel was not obliged to give any statement of reasons at all for its determination,[63] but the statement of reasons it did give indicated that, in coming to its conclusion against Ms Hart, it gave considerable weight to her unrelated pre-accident injuries. It is no longer said by the plaintiff, if it was ever said, that this was not open to the Panel. In any event, the Panel was not bound to accept everything stated by Associate Professor Danks or Mr Goldschlager. Further, unlike those doctors, Mr Kudelka did not emphasise the problems at L1/2 and L2/3. In his report (dated 3 March 2014), he merely mentioned the imaging results for those spinal levels, but did not otherwise discuss or even refer to those levels as being any source of then current difficulty for Ms Hart. Rather, he confined himself to the lower levels of Ms Hart's lumbar spine (L3 to S1), saying that her injury was an aggravation of previous surgery in that area. Indeed, he expressed a view against Ms Hart undertaking any further surgery to her spine. In his statutory certificate of assessment, under the heading 'Brief Description of Injury Assessed', Mr Kudelka stated only the following: 'Aggravated lumbosacral pain from previous spinal surgery'. It is not for this Court to opine as to the apparent strength or otherwise of that part of Ms Hart's claim that was based on the pre-surgery condition of her spine at levels L1/2 and L2/3, especially where Ms Hart had such an extensive history of lower back problems before the alleged incident of April 2012.[64]

42 In summary, even if (contrary to my view) there was some error of nomenclature, it is clear that the Panel did not omit to consider and take into account the pre-surgical condition of Ms Hart's spine at L1/2 and L2/3. Ms Hart's first complaint must fail.

The plaintiff's second complaint: the effects of the spinal surgery

43 As mentioned above, the plaintiff's second (and last remaining) complaint is that the Medical Panel wrongly regarded itself as being precluded, by the 'direction' in the AMA Guides, from including in its assessment any evaluation of any degree of impairment resulting from the spinal surgery itself. If this point were a good one, it would warrant the quashing of the Medical Panel's determination for error of law on the face of the record or jurisdictional error or both.

44 The plaintiff's arguments in support of her second complaint are relatively short and simple. In substance, she says that the Act takes precedence over the AMA Guides and that the Act requires a Medical Panel to assess every injury alleged in a claimant's claim; that the fusions at levels T11/12 and T12/L1 are to be regarded as included in the injuries alleged in the claim; and that the Medical Panel was therefore bound to assess those fusions but declined to do so.

45 The plaintiff submits that the task and obligation of a Medical Panel under Part VBA is to answer the medical question referred to it. She points out that s 28LB provides that 'medical question in relation to a claim for damages, means a question as to whether the degree of impairment resulting from injury to the claimant alleged in the claim satisfies the threshold level'; and she says that the question referred in the present case[65] answered that description. Therefore, she submits, the Panel was obliged to determine whether the degree of impairment resulting from all the injuries alleged in the claim, including the two fusions, satisfied the threshold level.

46 According to the plaintiff, nothing in the AMA Guides, including the 'direction', can validly operate to countermand the statutory obligation of the Panel to assess all of the injuries alleged in the claim. In any event, she submits (basing herself partly on certain observations made by Nettle JA in Mountain Pine Furniture Pty Ltd v Taylor[66] which are set out below), on the proper construction of the Act and the 'direction', the direction does not apply to a 'further' injury involved in or caused by surgery to treat an injury alleged to have been caused in turn by the alleged fault of a proposed defendant. She says that the surgery of 19 July 2014 involved or caused 'further' injuries to the plaintiff's spine, at least at T11/12 and T12/L1; that these 'further' injuries were not mere signs or symptoms of the initial (MUW - caused) alleged injuries; and that therefore the 'direction' at page 100 of the AMA Guides did not apply to them. She calls in aid the fact that the Panel itself took into account the scarring of her skin that was consequential on the surgery. The plaintiff further calls in aid the principle of legality, submitting that clear words are necessary to justify a conclusion that her common law right to sue for damages for non-economic loss is restricted in the way in which the Medical panel, in effect, understood it to be restricted.[67]

47 Further or alternatively, the plaintiff submits that the two upper level fusions were not 'surgery to treat an impairment' within the meaning of the 'direction', but rather were surgery to prevent or guard against a future injury or impairment.[68]

48 MUW advances a range of submissions in response to the plaintiff's second complaint.[69] Subject to certain limited qualifications and comments, as indicated below, I accept MUW's submissions in response. The result is that the plaintiff's second complaint fails also.

49 The following account of the facts and the holdings in the Mountain Pine litigation is based on the judgments given by Bongiorno J (as his Honour then was) in December 2006 in Taylor v Mountain Pine Furniture Pty Ltd[70] and the judgment of the Court of Appeal (on appeal from Bongiorno J) in July 2007 in Mountain Pine Furniture Pty Ltd v Taylor.[71]

50 Mr Taylor suffered injury to his neck and left big toe in the course of his employment with Mountain Pine Furniture Pty Ltd ('Mountain Pine') on 27 November 1997. The injury to Mr Taylor's neck involved a fracture dislocation of C6-7 with mild spinal canal displacement, as well as what is described in the AMA Guides as loss of motion segment integrity. It was treated by surgery involving internal fixation and a C6-7 fusion. Mr Taylor recovered well from the surgery and his post-surgery complaints were limited to stiffness and aching most of the time in the sides of the neck and some pins and needles in the tips of his middle, ring and little fingers of both hands at night. Relevantly, after the surgery the positioning of Mr Taylor's C6 vertebra with respect to his C7 vertebra was insufficient to quantify as loss of motion segment integrity as described in the AMA Guides.

51 On 16 July 1999, Mr Taylor submitted a claim for compensation for non-economic loss under s 98C of the AC Act, as that Act then stood,[72] in respect of the injuries to his neck and his toe. The claim was accepted by the appointed WorkCover agent. The amount of compensation payable under s 98C of the AC Act in relation to a physical injury was to be calculated based on the degree of impairment.[73] In the first instance, an assessment of the degree of impairment was required to be obtained by the WorkCover agent by arranging an independent examination by a medical practitioner in accordance with the AMA Guides.[74] A dispute having arisen as to the degree of impairment, the agent was required to refer the dispute to a Medical Panel in the form of a medical question.[75] That is what occurred in relation to Mr Taylor's claim. The medical question was:

What is the degree of impairment resulting from the accepted injury/s assessed in accordance with Section 91 and is the impairment permanent?

52 A Medical Panel assessed Mr Taylor in accordance with the AMA Guides, pursuant to s 91 of the AC Act, and, on 5 January 2004, it gave an opinion, pursuant to s 68 of the AC Act as it then stood, that Mr Taylor had a 16 per cent whole person impairment resulting from the accepted injuries and that the degree of impairment was permanent ('the first Panel's opinion'). On 1 September 2004, the first Panel's opinion was quashed by this Court, on the application of Mr Taylor, on the ground that its reasons for reaching its conclusion were inadequate and that it had failed to accord Mr Taylor procedural fairness.[76] The matter was remitted for reconsideration and redetermination.

53 On 19 November 2004, a differently constituted Medical Panel ('the second Panel') delivered its determination on the reconsideration. The second Panel provisionally assessed Mr Taylor's pre-surgery whole person impairment with respect to the neck injury to be 25 per cent, based on it being a cervicothoracic spine Category IV impairment pursuant to Table 73 of the AMA Guides, which is described as 'Loss of motion segment integrity or multilevel neurologic compromise'.

54 However, the second Panel observed[77] that to assess the pre-surgery condition of Mr Taylor's neck in pursuance of the 'direction' would be in 'apparent conflict' with the following statement in Section 1.1 of the AMA Guides:

The Guides defines 'permanent impairment' as one that has become static or stabilized during a period of time sufficient to allow optimal tissue repair, and one that is unlikely to change in spite of further medical or surgical therapy.

The Panel considers that for there to be a meaningful clinical basis for a finding that a certain degree of impairment is permanent, it must be a degree of impairment which is unlikely to change in spite of further medical or surgical therapy. Therefore, as it is clear that surgery did alter the degree of impairment, the Panel concluded that notwithstanding the paragraph on page 100 of Chapter Three of the Guides, the degree of impairment resulting from accepted neck injury in this case should be based on the post-surgery condition.

56 As a result, the second Panel assigned a whole person impairment of 15 per cent to the neck injury. It assessed Mr Taylor's post-surgery condition as coming within Category III of Table 73, rather than Category IV, because of, among other things, the absence of loss of motion segment integrity post-surgery.

57 Mr Taylor challenged the second Panel's determination by way of an application for judicial review. Bongiorno J held that the Panel had erred in not giving effect to the 'direction'.

58 His Honour began by drawing attention to the context provided by the two paragraphs which precede the 'direction', and which are as follows:[79]

The Injury Model attempts to document physiologic and structural impairments relating to insults other than common developmental findings, such as (1) spondylolysis, found normally in 7% of adults; (2) spondylolisthesis, found in 3%; (3) herniated disk without radiculopathy, found in more than 30% of individuals by age 40 years; and (4) ageing changes, common in 40% of adults after age 35 years.

The Injury Model relies especially on evidence of neurologic deficits and uncommon, adverse structural changes, such as fractures, dislocations and loss of motion segment integrity. Under this model, DREs are differentiated according to clinical findings that are verifiable using standard medical procedures.

[20] This description makes it clear that evaluation using this model or method concentrates on the degree of severity of the insult on the spine by the traumatic event which caused the permanent impairment, measured by reference to its effect on the patient. It is in this context that it directs the examiner to ignore the effect of surgery. Examples given as illustrations of the use of the Injury Model show that the intention of the Guides is to remove from account any effect of surgery - remedial or adverse. One example, pertaining to the lumbosacral spine, assessed a patient who had a positive result from a disc removal and spinal fusion to treat a herniated nucleus pulposus at L4. The example specifically took out of account the effect of surgery. Another example, closer to the problem in Mr Taylor's case, concerned a patient who had had successful surgery to fuse her C5-C6 joint to treat a large herniated nucleus pulposus between those two vertebrae, with radiculopathy present with respect to C6. Her permanent impairment was also assessed as if the surgery had not been performed.

[21] The Accident Compensation Act 1985 requires the Medical Panel to assess impairment using the AMA Guides. This attempt by the legislature to introduce some degree of objectivity into the assessment of impairment for compensation purposes represents a significant application of the rule of law in an area where one of the fundamental principles of justice - that like cases should be treated alike - has particular importance. Nothing would discredit a compensation system more quickly than the idiosyncratic application of criteria to the determination of an injured person's impairment and hence their entitlement to compensation at a particular level. Although the efficacy of the application of the AMA Guides to achieve a just result for injured people may be debated, as the law stands they must be applied regardless of any personal view of the assessor called upon to make the assessment. Whilst the interpretation of medical matters referred to in the Guides and the exercise of clinical judgment must be left to the medical examiner who is applying them, it is not within that medical examiner's remit to ignore an express direction contained in the Guides as to how a particular objective fact is to be treated in making an assessment. Thus it was not within the power of the Medical Panel in this case to reach its assessment of Mr Taylor's impairment after taking into account the effects of surgery performed on his cervical spine.

[22] That the Guides require the effects of surgical intervention on the spine to be ignored in assessing permanent impairment does not mean that the fact that surgery has been undertaken must be ignored by the assessor. On the contrary, the assessor must ensure that the effects of any surgery are carefully noted so that they can be consciously disregarded in reaching a conclusion as to permanent impairment. If surgery has been successful (as in this case) the assessor looks only at the effect or effects of the trauma on the pre-operation patient, applies Table 70 to those effects (or, where necessary, considers other criteria provided by the Guides to reach an appropriate conclusion) and proceeds to the whole person impairment assessment provided by applying the result obtained from Table 70 to Table 73.

[23] Where surgery has been unsuccessful the task of the assessor may, in some cases, be somewhat more difficult. It is the effect of the surgery which must be ignored in reaching an assessment. Thus, any sign or symptom of the original injury still present after the surgery must be taken into account in applying Table 70. Those detriments which must be ignored are those actually caused by the surgery; that is to say which can be said to have been a result, not of the original trauma, but of the surgery itself. It is only "changes in signs or symptoms that may follow surgery" that are to be ignored; in this instance the word "follow" is synonymous with "caused by". That this is so is reinforced by the Guides' emphasis that it is a favourable or unfavourable response to treatment which must be ignored. Any other interpretation of the requirement that surgery be ignored which did not differentiate between the effect of the original trauma and the effect of the surgery could lead to grave injustice to the injured person. A failure to so differentiate those effects would introduce an unacceptable risk of injustice in the assessment of impairment and thus the assessment of compensation. It is clearly not a requirement of the Guides.

60 In so holding, Bongiorno J disagreed with the decision of Balmford J in Bayliss v Transport Accident Commission,[81] in which her Honour considered the 'direction' in the context of an appeal from VCAT concerning an impairment assessment made by the Transport Accident Commission. Balmford J had resolved the conflict between the general principle in the AMA Guides that an assessment of permanent impairment should only be made when the patient's injuries have stabilised and the 'direction' by concluding that the 'direction' was 'an oversight'. Bongiorno J said:[82]

With respect to Her Honour, I am unable to agree with such a characterisation. The meaning of the direction is entirely clear. It runs to six lines in a part of the Guides describing the Injury Model of assessment with respect to spinal injuries. An oversight is an inadvertent mistake. I find it impossible to so characterise the clear words of the paragraph at page 100 of the Guides to which I have referred. As I hope I have already made clear the Injury Model of assessment concentrates on the injury to the patient's body effected by the trauma. It is entirely consistent with such an approach that the effects of surgery - whether successful or unsuccessful - should be ignored.

61 Bongiorno J further suggested, in relation the reasoning of Balmford J in Bayliss, that the requirement that a patient's injuries be assessed only once they have stabilised is a directive as to when an assessment should take place, while the 'direction' is a directive as to how how an assessment is to be undertaken. On his Honour's view, therefore, there was no conflict.[83]

62 Mountain Pine appealed against the decision. The Court of Appeal (Vincent, Nettle and Ashley JJA) dismissed the appeal. It seems that the order made by the Court of Appeal was simply an order dismissing the appeal. It seems that the Court of Appeal did not include in its order any direction to the Medical Panel which might have varied the effect of the order made by Bongiorno J. That order, in turn, had been an order quashing the determination of the Medical Panel and requiring that the medical question be forthwith determined by the same Medical Panel 'according to law and in accordance with this judgment'. In other words, even after the conclusion of the appeal to the Court of Appeal, the medical question was to be redetermined in accordance with the judgment of Bongiorno J.

63 In the Court of Appeal, Nettle JA (with whom Vincent and Ashley JJA agreed) gave the leading judgment. Nettle JA agreed with Bongiorno J that it was inherently improbable that the 'direction' was an 'oversight'.[84] His Honour conceded[85] that the 'direction' appears at first to be opposed to a fundamental tenet of the AMA Guides, namely that they are directed to the assessment of permanent impairments, which are defined as adverse conditions that are static or stabilised and unlikely to change in spite of further medical or surgical therapy.[86] However, Nettle JA went on to say:[87]

... But the nature of spinal injury is such, and the terms of the direction are so clear, as in my view to show that in the case of spinal injury the direction was intended to override the assessment approach observed elsewhere in the Guides and to substitute for it an assessment based upon the nature of the injury before surgical intervention. As yet there is no known technique of restoring a damaged spine to a state of perfect integrity. The spinal injury once done will forever remain no matter what may be done by way of surgery to alleviate the suffering which it causes. For that reason, a spinal injury is properly to be regarded as an impairment despite any improvement in signs or symptoms the consequence of surgery. Hence the need for the approach in the case of spinal injury for which the s 3.3 direction provides.

64 Nettle JA drew attention to two examples given in the AMA Guides. The first example relates to Lumbosacral Spine Impairment:[88]

Example 2: A 45-year-old woman had onset of back and right-leg pain immediately after being in a crash. She had a history of mild intermittent back pain but denied ever having had leg pain. Roentgenograms taken in the emergency room on the day of the crash and repeated at a later clinic visit showed significant slipping of L4 on L5 that was measured at 7 mm.

Examination of roentgenograms taken years earlier in an orthopedist's office demonstrated significant spondylolisthesis between L4 and L5.

Conservative treatment of the woman's symptoms was ineffective, and she developed signs of a radiculopathy on the right side, with diminished reflexes and a positive straight-leg-raising test. A magnetic resonance image showed a herniated nucleus pulposus at L4.

The woman underwent an operation for disk removal and one-level spine fusion. She did well after the operation, her signs and symptoms receded, and she resumed full daily activities. Ten months after the injury, when her condition was stable, the physician evaluated her condition.

Impairment: Lumbosacral category III (Table 72, p 110); 10% whole-person impairment.

Comment: The woman had a ruptured disk as a result of the crash. The resolution of her symptoms after a surgical procedure does not reduce the impairment estimate. The slipping of L4 on L5 shown after the crash does not enter into the estimate, because the responsible condition was present years earlier, according to roentgenographic evidence.

The second example relates to Cervicothoracic Spine Impairment:[89]

Example 2: A 28-year-old athlete had a C5 vertebral body fracture with almost 50% compression and had radicular pain in the left arm, which was verified as a C6 level radiculopathy by positive sharp waves in three arm muscles. The man underwent a three-level posterior fusion. After his condition became stable, he had no bladder problems, but he was unable to walk without leg braces.

The patient's impairment was in cervicothoracic category III and also in category VI because of the lower extremity weakness. The category III impairment of 15% would be combined with a 40% category VI[90] impairment representing lower extremity weakness.

Impairment: 49% whole-person impairment; this represents 15% combined with 40% (Combined Values Chart, p 322).

65 While the first example was consistent with giving effect to the 'direction',[91] Nettle JA concluded that the second example could not be reconciled with the 'direction'. However, his Honour concluded that it was more likely that the example was wrong and therefore should be ignored to the extent that it was inconsistent with the 'direction'.[92]

66 As part of his reasoning towards that conclusion, Nettle JA said:[93]

I have tried unsuccessfully to construe the s 3.3 Direction and the example in a manner that will make sense of both provisions. I thought for a time that it may be appropriate to treat the s 3.3 Direction as directed to "signs and symptoms" as opposed to the injuries from which they result, and so deal with the example on the basis that lower extremity weakness to which it refers was to be regarded as an injury as opposed to a sign or symptom. But with the benefit of counsel's further submissions, I can see that the idea was misconceived. As counsel for both parties in effect submitted, there is no clear distinction between an injury and signs and symptoms for the purposes of the Guides, and possibly for the purposes of medicine generally. Not infrequently, an illness or injury and signs and symptoms are the same thing and understandably much of s 3.3 of the Guides and the impairment tables which it contains are premised on that basis.

67 Having stated his conclusion that, to the extent of the inconsistency, the example should be ignored, Nettle JA made certain observations in paragraph 34 of the judgment, under the heading 'Later Injury', upon which Ms Hart now relies heavily.[94] Nettle JA said:[95]

So to conclude raises the question of whether, if the facts were as in the example, the injury constituted of the "lower extremity weakness" would be compensable under the Act. To put the problem more generally, would the added impairment involved in an unfavourable response to surgery be compensable? As at present advised, I tend to think that it would be. For the reasons just expressed, I consider that the s 3.3 Direction would preclude its consideration in the "original assessment of the impairment". But as counsel for the first respondent submitted, one may suppose that the added impairment would constitute a "further injury" occurring while the worker was at a place for medical or surgical treatment within the meaning of s 83(1)(d) of the Act.[96] I add that we have not heard full argument on the point and, strictly speaking, it need not be decided for the purposes of this appeal. But as a matter of first impression it would be surprising if further impairment were not covered in the manner suggested.

I note that s 83(1)(d) of the AC Act deemed an injury 'while the worker is in attendance at any place for the purpose of obtaining a medical certificate, receiving medical, surgical or hospital advice, attention or treatment, receiving a personal and household service or an occupational rehabilitation service or receiving a payment of compensation in connection with any injury for which the worker is entitled to receive compensation or for the purpose of submitting to a medical examination required by or under this Act' to have occurred in the course of employment. The effect of this was that the injury was compensable under the AC Act.[97] Section s 83(1)(d) of the AC Act has no equivalent in the (Wrongs) Act.

68 Nettle JA went on to reject an argument advanced by Mountain Pine to the effect that it would be absurd to require consideration of the DRE Impairment Category Differentiators, such as 'guarding', 'loss of reflexes' and 'loss of motion segment integrity', in Table 71[98] as part of a post-surgery examination only to mandate that those results be excluded from consideration in accordance with the 'direction'. His Honour instead found that this did not produce inconsistency, with the examples demonstrating how a physician could use the differentiators consistently with the 'direction' in a post-operative assessment.[99]

69 Nettle JA also rejected Mountain Pine's further argument that the references in Table 70 to 'Previous spine operation' and the ascription of impairment categories to those descriptions[100] present difficulties with respect to giving effect to the 'direction' where a patient's spine has been operated on both prior to the injury and post-injury.[101]

70 In response to Mountain Pine Pty Ltd v Taylor, the following new sub-ss (1A) and (1B) were inserted into s 91 of the AC Act:[102]

(1A) Despite anything to the contrary in the A.M.A Guides, an assessment under subsection (1) of the degree of impairment resulting from an injury must be made -

(b) subject to subsection (7), based on the worker's current impairment as at the date of the assessment, including any changes in the signs and symptoms following any medical or surgical treatment undergone by the worker in respect of the injury.

(1B) The A.M.A Guides apply in respect of an assessment under section 3.3d of Chapter 3 of the A.M.A Guides as if the following were omitted -

"with the Injury Model, surgery to treat an impairment does not modify the original impairment estimate, which remains the same in spite of any changes in signs or symptoms that may follow the surgery and irrespective of whether the patient has a favourable or unfavourable response to treatment".

Similar provisions were inserted in the Transport Accident Act 1986 by the same amending statute.[103] No equivalent amendment was made to Part VBA of the (Wrongs) Act, even though at all relevant times Part VBA has made special mention of the assessment of spinal injuries[104] and even though that special mention was in fact amended in 2015 to specify that the 'threshold level' in the case of a spinal injury would thereafter be 'impairment of 5 per cent or more'.[105]

MUW's submissions in relation to the plaintiff's second complaint

71 MUW acknowledges that the Panel found that the surgery caused a loss of function in both the lumbosacral and thoracolumbar sections of Ms Hart's spine. MUW also acknowledges that the relevant loss of function may come within a category of impairment included in Table 70 of the AMA Guides. Therefore MUW properly accepts that if the Panel misconstrued either the Act or the effect of the 'direction' then its determination would need to be quashed and the matter would need to be remitted to a Medical Panel for reconsideration.[106]

72 MUW's primary submission is that the 'direction' is to be given effect. It submits that Mountain Pine Furniture Pty Ltd v Taylor stands for the proposition that the 'direction' is to be given effect, notwithstanding that it is an anomaly to the general proposition that impairments are to be assessed as at the time of assessment.[107]

73 In particular, MUW submits that to construe the 'direction' as precluding the assessment of consequences of surgery when assessing the original injury, but as not precluding the treatment of surgery as constituting or causing further injury, would do violence to the language of the 'direction' and the concept encapsulated within it. If an assessor may take deterioration of a patient's condition following surgery as a further injury then the direction would only exclude improvement caused by surgery, whereas it is equally expressed to cover unfavourable responses to surgery. In a situation where surgery has resulted in improvement in some respects and worsening in others, this interpretation would mean that the patient's improvement could not be taken into account in the assessment but the worsening could be assessed as a further injury. MUW submits that this would distort the Injury Model, and offend the golden rule of statutory construction. [108]

74 MUW submits that construing the 'direction' in the manner for which it contends does not bring the 'direction' into conflict with the statutory task, as asserted by Ms Hart. According to MUW, it is an oversimplification to say that the Panel's statutory task was to assess all the injuries alleged in the claim. The statutory task was to assess the injuries in the claim in accordance with the Act, and s 28LH(1) obliged the Panel to conduct the assessment in accordance with the AMA Guides, which include the 'direction'. Further, s 28LL(1) required the Panel to include all impairments that arose out of the same incident in the one assessment. The statutory task, therefore, involved conducting an assessment where all impairments were dealt with in the one assessment and in accordance with the AMA Guides.[109]

75 MUW argues that 'assess' in the Act means to turn one's mind to considering an award of impairment, that is, to conduct the exercise, rather than to reach a positive numerical determination of impairment. MUW says that this interpretation is supported by the wording of ss 28LZG(5) and (6) of the Act, which both distinguish between 'making an assessment' and being able to 'determine the medical question'. The statutory task, MUW submits, is to assess, in the sense of carrying out the assessment process, in accordance with the AMA Guides.[110]

76 Accordingly, MUW submits, when the Panel in its reasons stated that, by reason of the direction, it considered that it was 'precluded from assessing any additional thoracolumbar spine impairment resulting from the injury',[111] it did not mean that it had not considered the alleged injury to the thoracolumbar spine (which might have been a failure to carry out the statutory task) - it merely meant that it considered itself precluded from ascribing an impairment value to the claimed injury.[112]

77 Hence, according to MUW, the Panel duly performed its statutory duty to carry out the assessment process in relation to the claimed surgical injury. It regarded the surgical injury as an injury alleged in the claim and turned its mind to whether it fell to be assigned an impairment rating under the AMA Guides. That the Panel considered the injury is clear from the fact that it specifically noted that treatment to Ms Hart's claimed injury had resulted in loss of function in both the lumbosacral and thoracolumbar sections of her spine. In reliance on the 'direction', the Panel simply considered that it was precluded from assigning an impairment rating to the injury. The Panel fulfilled its statutory task in relation to the medical question referred to it by assessing all the claimed injuries, including the surgical injury, in the one assessment in accordance with the Act.[113]

78 Further or alternatively, MUW submits, the principle encapsulated in the maxim expressum facit cessare tacitum means that the specific prohibition in the 'direction' is not to be circumvented by the general duty to assess all the injuries in the claim asserted by Ms Hart.[114]

79 In making submissions on the proper role of the 'direction' in an assessment, MUW refers to the view expressed by Nettle JA in Mountain Pine Pty Ltd v Taylor that the rationale behind the direction is that a spine, once injured, can never be restored completely.[115] MUW also relies on the reference in the AMA Guides to the Injury Model applying 'especially to patients' traumatic injuries'. [116] MUW says that the Injury Model, of which the 'direction' forms a part, represents an exception to the assessor's usual role of looking to the stabilised condition of the patient as at the time of assessment; and that the exception is apparently based on a view, reached by the authors of the AMA Guides and adopted by Parliament, that the nature of spinal injuries warrants it.[117]

80 MUW argues that this exception takes the patient's spinal injury, in its pre-surgical state, as a proxy for the current condition of the patient's spine. The assessor still determines which region of the spine was principally affected, and then assesses impairment having regard to the injury that was sustained to that region. The assessor does so by looking to the differentiators within each category relating to the relevant region. If more than one spinal region was injured, then any further impairments are evaluated and included in the overall assessment in accordance with the AMA Guides. Thus, according to MUW, the original injury, as discerned and evaluated by specific differentiators, is being used as a proxy for the current condition of the patient's spine.[118]

81 Further, MUW argues, because the 'direction' (appearing as it does in a part of section 3.3 (s 3.3(d)) of the AMA Guides that applies to the whole of the Injury Model) covers all spinal regions, the same approach applies to the whole spine. That is, the 'signs or symptoms' referred to in the 'direction' are not limited to those manifest in the same spinal region as was affected by the initial injury. This is said to be consistent with s 28LL(1), which requires all impairments resulting from injuries which arose out of the same incident to be included in the one assessment.[119]

82 MUW also makes a number of points in relation to the observations made by Nettle JA in Mountain Pine Pty Ltd v Taylor at paragraph 34 under the heading 'Later Injury'. First, MUW notes that his Honour's comments were obiter and were acknowledged to be made as a matter of first impression without the benefit of full argument. Secondly, MUW relies on the point, noted above, that s 83(1)(d) of the AC Act (which was referred to by Nettle JA and which effectively deemed to be compensable an injury caused by surgery to treat the initial injury) has no counterpart in Part VBA of the (Wrongs) Act. The claim in Mountain Pine Pty Ltd v Taylor related to statutory compensation. Accordingly, to the extent of any inconsistency, there was more room for a provision such as s 83(1)(d) to prevail over the AMA Guides. MUW submits that inconsistency of that kind does not arise in the context of Part VBA of the (Wrongs) Act, which does not create a statutory entitlement to compensation but, instead, restricts recovery of common law damages.[120]

83 According to MUW, the fact that the Medical Panel took into account Ms Hart's surgical scarring is not inconsistent with the 'direction'. The 'direction' only applies to spinal injuries. Surgical scarring is not such an injury. It falls to be assessed under a different section of the AMA Guides entirely. Likewise, MUW submits that if spinal surgery, or anaesthesia for spinal surgery, results in a brain injury, the direction would not inhibit assessment of the brain injury.[121]

84 In relation to Ms Hart's argument that the Panel's application of the 'direction' would interfere with her common law right to damages and that, by virtue of the principle of legality, the direction should not be so applied without clear statutory intent, MUW says that there is clear intent. According to MUW, the intention of Part VBA of the (Wrongs) Act is to limit the right to recover damages for non-pecuniary loss where the injury falls below a threshold level when assessed in accordance with the AMA Guides. Further, at common law a plaintiff does not have a separate right of action in respect of a consequential surgical injury against the original tortfeasor. The plaintiff has a single cause of action for damages for loss which was caused by the negligent act of the tortfeasor. Therefore, MUW says, by causing the putative plaintiff's impairments to be assessed in a single assessment, in accordance with the AMA Guides, including the 'direction', Parliament is not interfering with any right to have the consequential surgical injury assessed separately. Such a right does not exist.[122]

85 In opposition to Ms Hart's argument that her surgery, insofar as it was constituted by the fusions at T11-12 and T12-L1, was not 'surgery to treat an impairment' but rather surgery to prevent further injury, MUW submits that it is possible for the surgery to serve both functions and that there is nothing in the 'direction' to say that the surgery must only, or primarily, be to treat an impairment. It is enough, MUW says, if the surgery is to treat an impairment. In any event, if this was not surgery to treat an impairment caused by the incident in April 2012, then Ms Hart's claim in relation to it would fail for want of causation and so could not form part of the assessment.[123]

86 MUW also submits that, under the Injury Model, the differentiators between impairment categories are the relevant 'signs or symptoms'. Post-incident surgery itself is not a differentiator. If the direction were not to preclude assessing a surgical injury as a 'further injury', then the impairment (if any) associated with the surgical injury could only be determined on the basis of a change in signs or symptoms resulting from the surgery. Whether or not the surgery is considered a 'further injury', the direction prohibits such a change in signs or symptoms to be taken into account.[124]

87 MUW further submits that its argument that the Injury Model does not contemplate the assessment of the consequences of surgery is strengthened by the fact that Table 70, which relates to the Injury Model, does not include any reference to surgery, except prior surgery,[125] but Table 75, the table relating to the Range of Motion model, does attribute degrees of impairment for surgery. [126]

Analysis of the submissions on the plaintiff's second complaint

88 Subject to what appears below, I accept the submissions made on behalf of MUW relating to the plaintiff's second complaint.

89 I do not fully accept the meaning given by MUW to the expression 'changes in signs or symptoms that may follow the surgery' which is contained in the 'direction'. In my view, the expression does not itself extend to cover the very surgery in question or any injury constituted by the surgery. The Medical Panel seems to have misread the expression in the same way as MUW does in its submissions. However, the misreading is of no moment. The critical words of the direction are the opening words, namely 'With the Injury Model, surgery to treat an impairment does not modify the original impairment estimate'. What follows thereafter is included not in order to confine those words in any way but rather to remove any doubt about the very broad scope of the opening words and of the 'direction' as a whole in relation to the Injury Model.

90 As MUW submits, the Injury Model is injury based, not present condition based. The effect of the 'direction' is to make the initial injury and its effects a proxy for the present condition of the injured person. To allow the ordinary, expected effects of surgery to be considered as a 'further injury' would be inconsistent with the Injury Model. It would be more than odd to require an assessor to assess the pre-surgical condition of a person's spine (which by definition must be in a state of permanent impairment except for the prospect of surgery) and then to add a further impairment percentage for the fact or the effects of the very thing directed to be disregarded in the first place, namely the surgery. Moreover, as mentioned above, Table 70, which relates to the Injury Model, does not include any reference to surgery, except prior surgery, whereas Table 75, the table relating to the Range of Motion model, does attribute degrees of impairment for surgery. As MUW submits, this confirms that it is not anticipated that surgery to treat an initial impairment will also be treated as an injury or impairment under the Injury Model. Indeed, rather strikingly, Table 75 expressly lists the very types of surgery that Ms Hart underwent, namely fusions and decompressions (which include laminectomies) as assessable impairments, whereas (apart from the more generally expressed reference to 'previous spinal operation' mentioned above) there is no corresponding entry in Table 70. It is true that a fusion or another kind of surgery might conceivably fit within Table 70, say as a 'multilevel spine segment structural compromise', which is a species of 'structural inclusion' which may bring a person within DRE Lumbosacral Category IV. Indeed, as already mentioned, MUW acknowledges this possibility. But, in my view, such an outcome would only arise where the fusion or other surgery was the initial injury, such as in a claim against a surgeon.[127] The 'direction' would preclude it from arising in a case like the present.

91 The plaintiff's arguments cannot stand with Mountain Pine Pty Ltd v Taylor. There is no sufficiently relevant or significant distinction (helpful to the plaintiff) between the provisions of Part VBA and the corresponding provisions of AC Act as they stood at the time of Mountain Pine.[128] Indeed the Injury Model, with its principal focus being on traumatic or frank injuries, sits well with Part VBA, which is all about determining whether an injured person is to be permitted to bring a claim for non-economic loss against a particular person or entity based on the alleged fault of that person or entity. Section 28LL(1) and (2) expressly contemplate that commonly, at least, the impairment or impairments to be assessed will have resulted from an injury or injuries which arose out of a particular 'incident'.

92 The obiter observations in paragraph 34 of the judgment of Nettle JA in Mountain Pine are not to be taken to undermine anything that is said elsewhere in his Honour's reasons or that was said below by Bongiorno J. In any event, nothing said by Nettle JA indicates that the 'direction' can be avoided by pointing to the surgery itself, as distinct from some unexpected detrimental consequence of surgery amounting to a distinct injury. As MUW submits, paragraph 34 is also distinguishable on the basis that it is tied to s 83(1)(d) of the ACA, whereas there is no direct equivalent in the (Wrongs) Act. The fact that the common law allows recovery for surgically caused further injuries (provided that the chain of causation is not broken) does not gainsay this.

93 I also agree with MUW that there is no real basis for distinguishing between surgery directly related to the part of the spine injured in the relevant accident and surgery to nearby parts of the spine made necessary or appropriate by the need to carry out the principal aspect of the surgery.

94 During argument, senior counsel for Ms Hart acknowledged that, if his argument were accepted, there would be no work for the 'direction' to do at all 'in this context'.[129] In effect, he was acknowledging that, on Ms Hart's case, the 'direction' could never worsen the position of a claimant. That seems to be a most unlikely consequence of any proper understanding of the combined effect of the Act and the 'direction', especially having regard to the judgments in the Mountain Pine litigation.

95 In the present case, as mentioned above, there is no suggestion that the fusions (or any other part of the surgery) went wrong or caused any changes to the plaintiff's spine other than the very changes intended by the surgeon. Accordingly, the 'direction' precluded the fusions being treated as further injuries or as attracting an impairment rating. I need not, and do not, decide whether the direction would preclude giving an impairment rating to unexpected detrimental consequences of surgery.

96 For these reasons, the proceeding will be dismissed. I will hear the parties as to costs.

[1] For the general principles applicable to judicial review of a determination of a Medical Panel, see Wingfoot Australia Partners Pty Ltd v Kocak [2013] HCA 43; (2013) 252 CLR 480, 491-493 [24]-[28] (French CJ, Crennan, Bell, Gageler and Keane JJ).

[2] More detailed accounts of the relevant provisions of Part VBA of the Act are contained in Chua v Newman-Morris [2009] VSC 582 (Emerton J), [4]-[8]; Summers v Director of Housing [2012] VSC 395 (John Dixon J), [6]-[13]; Saddington v Kotzmann [2013] VSC 196 (Kyrou J), [3]-[6], [11]-[16]; Adam v Wadesley [2018] VSC 304 (Ierodiaconou AsJ), [80]-[88].

[3] See Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 664-5 [18].

[4] [2007] VSCA 146; (2007) 16 VR 659.

[5] [2009] VSC 311, [24]-[28].

[6] [2013] VSCA 235; (2013) 42 VR 434, [49] 446-447. This is noted by Ierodiaconou AsJ in Adams v Wadesley [2018] VSC 304, [28].

[7] [2009] VSC 311, [44]-[46].

[8] A corresponding requirement appears in s 28LH(1)(a) of the (Wrongs) Act.

[9] [2013] VSC 196, [21]-[29].

[10] Ibid [22]-[20] (footnotes renumbered).

[11] Barnett v Transport Accident Commission [1999] VSC 484; (1999) 15 VAR 414, 429-30 [30]; aff'd and reasons adopted in Barnett v Transport Accident Commission [2001] VSCA 12; (2001) 34 MVR 26.

[12] Gillat v Transport Accident Commission [2003] VSC 15; (2003) 38 MVR 463, 469 [27] ('Gillat').

[13] Transport Accident Commission v Elworthy [2007] VSC 48 (7 March 2007) [20] ('Elworthy').

[14] State Trustees Ltd v Transport Accident Commission [2002] VSC 428; (2002) 6 VR 359, 365 [25].

[15] Lake v Transport Accident Commission [1998] 1 VR 616, 626 ('Lake'); Connelly v MMI Workers Compensation (Vic) Ltd [2003] VSCA 60; (2003) 6 VR 555, 557 [9] ('Connelly').

[16] Lake [1998] 1 VR 616, 626; Connelly [2003] VSCA 60; (2003) 6 VR 555, 557-8 [9]; Elworthy [2007] VSC 48 (7 March 2007) [21].

[17] Elworthy [2007] VSC 48 (7 March 2007) [21].

[18] Martinez v Dynamic Engineering Construction Co Pty Ltd [2005] VSC 204 (9 June 2005) [10].

[19] Elworthy [2007] VSC 48 (7 March 2007) [20].

[20] Gillat [2003] VSC 15; (2003) 38 MVR 463, 473 [47].

[21] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 669 [33].

[22] See, eg, Waycott v Koffler (1983) 25 NTR 1, 8; Hutchins v Commissioner of Taxation (1987) 14 FCR 510, 529; Australian Capital Television Pty Ltd v Minister for Transport and Communications (1989) 86 ALR 119, 147-8; Walker v Wilson [1991] HCA 8; (1991) 172 CLR 195, 207-8; Re La [1993] FCA 62; (1993) 41 FCR 151, 158.

[23] See, eg, Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 666 [19], 668 [27]-[28]. The Medical Panel in the present case so referred to it: see below.

[32] Taylor v Mountain Pine Pty Ltd [2006] VSC 499, [15]-[20] (Bongiorno J); Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 662-664 [12] (Nettle JA, with whom Vincent and Ashley JJA agreed).

[33] At that time, the threshold level for spinal injury was 'more than 5%'. From 19 November 2015, it was amended to '5 percent or more'.

[34] In McAlister v Leitch [2011] VSC 51, I referred in some detail to s 28LW and other provisions in Part VBA that together create a scheme for the processing of claimants' claims.

[35] Transcript of proceedings, Hart v Melbourne Underwater World Pty Ltd (Supreme Court of Victoria, S CI 2016 02622, Cavanough J, 9-10 February 2017) ('transcript') 76.

[37] [2007] VSCA 146; (2007) 16 VR 659.

[39] See, e.g., Summers v Director of Housing [2012] VSC 395 (John Dixon J), [54]-[63].

[41] Plaintiff's written submissions in reply dated 2 February 2017 ('plaintiff's reply submissions'), [9(b)], [13].

[43] Originating motion dated 5 July 2016, [30]-[32], [33(k)], [33(l)].

[44] Plaintiff's reply submissions, [9(a)], [10], [11(a)], [15], [17], [22], [27].

[47] Plaintiff's initial written submissions dated 5 December 2016 ('plaintiff's initial submissions').

[48] Plaintiff's reply submissions, [9(b)], [13]; transcript 11-13, 17-27, 49-50, 191, cf 171-172.

[54] Dranichnikov v Minister for Immigration and Multicultural Affairs (2003) 197 ALR 389, 394-395 [24]-[27] (Gummow and Callinan JJ, Hayne J agreeing); Re Minister for Immigration and Multicultural Affairs; Ex parte Applicant S20/2002 [2003] HCA 30; (2003) 198 ALR 59, 71-73 [53]-[60] (McHugh and Gummow JJ); NABE v Minister for Immigration and Multicultural and Indigenous Affairs (No 2) [2004] FCAFC 263; (2004) 144 FCR 1 (Black CJ, French and Selway JJ), 17-18 [55]; LVR (WA) v Administrative Appeals Tribunal [2012] FCAFC 90; (2012) 203 FCR 166 (North, Logan and Robertson JJ), 198 [143]; Vellios Electrical Contractors Pty Ltd v Barton [2014] VSC 664 (Cavanough J), [78].

[55] Portland Properties Pty Ltd v Melbourne & Metropolitan Board of Works (1971) 38 LGRA 6, 18 (Smith J, Adam J agreeing); Ta v Thompson [2013] VSCA 344; (2013) 46 VR 10, 20 [50] (Osborn JA, Beach JA agreeing); Tan v Kotzman [2016] VSC 482 (John Dixon J), [29].

[57] The submissions of senior counsel for Ms Hart on this aspect are at transcript 140-143.

[59] Victorian Workcover Authority v Elsdon [2013] VSCA 235; (2013) 42 VR 434, 454 [84] (Bongiorno JA and John Dixon AJA), 445 [41]-[43] (Maxwell P, dissenting, but not as to this principle).

[60] Ibid 454 [83] (Bongiorno JA and John Dixon AJA). Section 28LH of the Act, read with the definition in s 28LB of 'approved medical practitioner', contemplates that the AMA Guides will be used for the purpose of making a medical assessment, at least in the first instance, by medical practitioners who have completed an approved training course. However, it is not completely clear whether, under the Act, members of medical panels, as distinct from 'approved medical practitioners', are required to have completed any such course.

[61] I refer to a special edition (No. S 305) of the Victoria Government Gazette, entitled 'Spinal Impairment Guides Modification Document', which was published on 6 October 2016. It contains guidelines, for the purposes of the Transport Accident Act 1986, modifying some aspects of the methods of assessing spinal impairment prescribed in the AMA Guides. The guidelines were developed by a panel of identified senior medical specialists and the Transport Accident Commission. Some parts of it represent departures from the AMA Guides. However, others are rather references to or comments on the existing terms of the AMA Guides. One such reference or comment is the following (at pages 3-4):

5.1 For the purposes of assessment of spinal impairment, there are three spinal assessment regions:

(a) the cervicothoracic (or cervical) region, which comprises the occipital condyle and the C1 to C7 vertebrae inclusive and includes motion segments C0-C1 to C7-T1 inclusively;

(b) the thoracolumbar (or thoracic) region, which comprises T1 to T12 vertebrae inclusive and includes motion segments T1-T2 to T11-T12 inclusively;

(c) the lumbosacral (or lumbar) region, which comprises the L1 to L5 vertebrae inclusive and includes motion segments T12-L1 to L5-S1 inclusively."

Plainly, this publication treats the spinal levels L1/2 and L2/3 as being within the lumbosacral spinal assessment region.

[62] Cf Minister for Immigration and Citizenship v Li [2014] FCAFC 1; (2013) 249 CLR 332. The originating motion was not clear in this regard.

[63] Colquhoun v Capitol Radiology Pty Ltd [2013] VSCA 58; (2013) 39 VR 296, 307 [42]-[44].

[64] See, generally, Alcoa Holdings v Lowthian [2011] VSC 245 (J Forrest J); Lingenberg v Gallichio [2013] VSCA 143; (2013) 40 VR 60 (Court of Appeal), 68-69 [28]-[34].

[66] [2007] VSCA 146; (2007) 16 VR 659, 669 [34].

[67] Transcript, 20-57. As to the principle of legality, see Francis Cardell-Oliver, 'Parliament, the Judiciary and Fundamental Rights: The Strength of the Principle of Legality' [2017] MelbULawRw 20; (2017) 41 Melbourne University Law Review 30.

[69] MUW's relevant submissions are at paragraphs [22] and [30]-[41] of its amended written submissions dated 25 January 2017 ('MUW's amended submissions') and at transcript, 59-60, 73-128, 130-140, 174-191.

[70] [2006] VSC 499, especially [3]-[10], [19].

[71] [2007] VSCA 146; (2007) 16 VR 659, especially 661-662 [10].

[72] Similar provision is made in Division 5 of Part 5 of the Workplace Injury Rehabilitation and Compensation Act 2013 ('the WIRC Act') for claims arising out of injuries sustained in the course of employment occurring on or after 1 July 2014.

[76] Taylor v Mountain Pine Furniture Pty Ltd [2004] VSC 324 (Williams J).

[77] See Taylor v Mountain Pine Furniture Pty Ltd [2006] VSC 99, [10]; Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 661-662 [10].

[78] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 661-662 [10].

[80] Taylor v Mountain Pine Furniture Pty Ltd [2006] VSC 499, [20]-[23].

[81] [2004] VSC 102; (2004) 9 VR 267 ('Bayliss').

[82] Taylor v Mountain Pine Furniture Pty Ltd [2006] VSC 499, [26].

[84] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 668 [27].

[88] Ibid 666 [20] quoting AMA Guides, 3/103.

[89] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 666-667 [21] quoting AMA Guides, 3/105.

[90] His Honour notes: 'In the text, this is printed as "IV" but it is a misprint, "IV" is demonstrably wrong'.

[91] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 668 [24], [27].

[94] Plaintiff's initial submissions, [30]; Plaintiff's reply submissions, [21]-[23].

[95] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 669-670 [34].

[96] Citing Kidman v Sefa [1996] VicRp 8; [1996] 1 VR 86, 88-89; Dunin v Harrison [2002] VSCA 125; (2002) 8 VR 596, 599.

[99] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 670-671 [40]-[41].

[101] Mountain Pine Furniture Pty Ltd v Taylor [2007] VSCA 146; (2007) 16 VR 659, 671 [42]-[43]. There may be some tension between, on the one hand, his Honour's comments here relating to the subtraction of degrees of impairment for prior injuries and, on the other hand, later authorities such as Alcoa Holdings v Lowthian [2011] VSC 245 (J Forrest J) and Lingenberg v Gallichio [2013] VSCA 143; (2013) 40 VR 60 (Nettle and Neave JJA), 68-69 [28]-[29]. However, any such tension is of no significance for present purposes.

[102] Inserted by Transport Accident and Accident Compensation Act Amendment Act 2007 s 25(3).

[103] Transport Accident and Accident Compensation Acts Amendment Act 2007 s 8(2) inserted sub-ss (2A) and (2B) into s 46A of the Transport Accident Act 1986.

[104] The Act, s 28LB, definition of 'threshold level', para (c).

[105] Wrongs Amendment Act 2015 s 11.

[106] Transcript, 77, 79, 83-84, 100-103, 110-111.

[107] Ibid 114; MUW's amended submissions, [35].

[108] Transcript, 112-3, 124-125; MUW's amended submissions, [39(e)], [39(h)]-[39(i)]; Grey v Pearson [1857] EngR 335; (1857) 6 HLC 61; 10 ER 1216, 1234 (Lord Wensleydale).

[111] See excerpt from the Medical Panel's statement of reasons above.

[113] Transcript, 77, 127. See excerpt from the Medical Panel's statement of reasons above.

[114] Ibid 125-126; MUW's amended submissions, [39(j)]; Anthony Hordern & Sons Ltd v Amalgamated Clothing and Allied Trades Union of Australia [1932] HCA 9; (1932) 47 CLR 1, 7 (Gavan Duffy CJ and Dixon J).

[115] [2007] VSCA 146; (2007) 16 VR 659, 668 [28]. See above.

[120] Transcript, 120-121, 126-127; MUW's amended submissions, [39(a)]-[39(d)], [39(f)].

[121] Ibid 116-120, 126; MUW's amended submissions, [44].

[124] Ibid 98-106; MUW's amended submissions, [41].

[125] Further, MUW submits that, as result of the judgment of Nettle and Neave JJA in Lingenberg v Gallichio [2013] VSCA 143; (2013) 40 VR 60, 68-69 [28]-[30], the reference to 'Prior spine operation' can no longer have a role in any assessment: transcript, 130-131, 133-135.

[127] See, eg, Tan v Gibbons [2016] VSC 652 (Ginnane J).

[128] Cf (Wrongs) Act ss 28LB (definition of 'medical question'), 28LWE and AC Act, s 104B(9).