1. On 3 February 2025 Luigi Russo (the appellant) lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Robin Alexander Mitchell, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on

6 January 2025. 2. The appellant relies on the following ground of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act): * the MAC contains a demonstrable error. 3. The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The Appeal Panel has conducted a review of the original medical assessment but limited to the ground(s) of appeal on which the appeal is made. 4. Rule 128 of the Personal Injury Commission Rules 2021 (the PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with r 128(1) of the PIC Rules. 5. The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed

1 March 2021 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed (AMA 5).

1. The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7.
2. As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination because although one was requested, we consider that we have sufficient evidence before us to enable us to determine this appeal for reasons we will set out more fully below.

1. The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.

1. Both parties made written submissions. They are not repeated in full, but have been considered by the Appeal Panel.
2. In summary, the appellant submits that the Medical Assessor erred in making a 100% deduction for a previous/pre-existing injury to the lumbar spine and right hip.
3. In reply, the respondent submits that no errors were made.

1. The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made.
2. In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
3. The appellant was referred to the Medical Assessor for assessment of whole person impairment (WPI) in respect of the left lower extremity (knee, hip), the right lower extremity (hip) as a consequential condition, the lumbar spine as a consequential condition and scarring (TEMSKI) resulting from an injury on 15 October 2019.
4. The Medical Assessor obtained the following history:

"Mr Russo said that he sustained an injury to the left knee joint at work on 4 June 2019 when he slipped, falling backwards and landing on his left knee.

He was employed at the time as a sheet metal worker.

There was a further aggravation on 15 October 2019, 4 months or so later, when he tripped on a piece of carpet and stumbled, without falling, and he attended his general practitioner who referred him to Dr Richard Walker, orthopaedic surgeon, who opined that his pain was not due to his left knee but rather coming from his left hip, recommending a left total hip replacement. Mr Russo obtained a 2nd opinion from orthopaedic surgeon Dr Arash Nabavi, who initially arranged PRP injections that were unhelpful, and then subsequently carried out a left total hip replacement on 30 November 2020.

He reported that his abnormal gait aggravated his lower back and right hip, which was also subject to hip joint replacement surgery 29 November 2021."

"He continues to have pain in the lower lumbar back centrally between a level of 4/10 and 8/10, on a Visual Analogue Scale, where a VAS of 0 is no pain and 10 would be the worst pain imaginable. and he has ongoing numbness in the 2nd, 3rd, and 4th toes of his left foot.

He also has pain in each hip, and each knee joint, particularly on the left side, treated with repeated PRP injections that were said to have been unhelpful.

He provided the following functional capacities of sitting for up to 30 minutes, standing and walking for between 30 and 60 minutes, driving for 50 km and lifting up to 10 or 15 kg."

1. The Medical Assessor then turned to consider Mr Russo's past history and said:

"He described previous low back injury from 1986, apparently involving 3 discs, which resolved over an extended period of time, thought to be approximately 5 years, before he was able to return to normal work duties again."

1. Findings on examination were reported as follows:

"He had a heavy stature weighing 107 kg for his height of 185 kg [sic] and he is right handed.

Lumbar back movements were reduced and were asymmetrical, with ¾ of normal flexion and ½ of normal extension possible, and ½ lateral flexion to each side. There was also a degree of guarding palpable in the lower thoracolumbar back. Reflexes were equal and normal in each leg and there was some patchy diminished sensation said to be present in the right S1 nerve distribution, without clear radicular objective signs clinically.

Hip joint movement was equal on each side at 90° of flexion, 15° of abduction and 15° of abduction, together with 30° external rotation and 15° internal rotation.

The left knee had normal extension at 0° and could flex to 120°, with no indication internal ligament or cartilage abnormality."

1. The Medical Assessor then set out details of the various investigations he had before him and said:

"Left knee MRI, 17 October 2019, undisplaced degenerative horizontal tear involving the anterior horn of the lateral meniscus and junction of the body and posterior horn of the medial meniscus. Patellofemoral and medial compartment degenerative changes.

Pelvis, left hip and left knee x-ray, 29 November 2019, severe degenerative changes in both hip joints suggestive of mild osteoarthritis and minor degenerative changes within the knee joint.

Whole body bone scan, 16 July 2020, mild to moderate osteoarthritic uptake in bilateral hips, knees particularly at the patellofemoral compartments and bilateral feet most prominent in the left subtalar joint region.

Bone scan with SPECT CT 19 April 2021, Active degenerative changes throughout the spine as well as intensely active osteoarthritic changes in the right hip and active osteoarthritic changes elsewhere as described. Transitional lumbarised S1 vertebra with mild activity at the lateral S1/S2 junctions most in keeping with low level pseudoarthrosis. Active bilateral patellar enthesopathy. No scan evidence of significant active lumbar facet arthritis, active synovitis, fracture or other significant focal bony abnormality, particularly in the lumbar spine or pelvis.

Lumbar spine MRI, 14 April 2022, mild lower lumbar spondylosis. Transitional lumbosacral junction with partial L5 sacralisation. Contact of some of the exiting lumbar nerve roots mainly at L4/5 due to neural exit foraminal and subarticular recess narrowing.

Bone scan dated 5 February 2024, No abnormal focal hyperaemia or delayed tracer uptake seen to suggest acute hardware complication related to the bilateral hip prostheses. There has been no significant change in the scan appearances since the last bone scan from 14/10/2022 and the scan findings are not suggestive of significant periprosthetic loosening Mildly active arthritic change again noted in the right sacroiliac joint."

1. He then summarised the injuries and diagnoses as follows:

"Mr Russo had long-standing pre-existing degenerative osteoarthritic changes in each hip joint and both knee joints, with an aggravation said to have occurred to the left hip and knee in the subject incident of 15 October 2019. The right hip had long-standing pre existing degenerative osteoarthritic changes and subsequently required total knee joint replacement. He attributed the development of right hip pain to favouring of the left leg however there was no frank injury to the right hip.

He has a history of a significant back injury condition from 1986, which resulted in him remaining off work for a period of 5 years which apparently involved discs at 3 levels in the lumbar spine, which was also said to have been aggravated in the subject work-related fall as described above."

1. The Medical Assessor made assessments as follows:

1. He then deducted 1/3rd in respect of the left lower extremity, knee and hip; 100% in respect of the right lower extremity- hip, and 100% in respect of the lumbar spine.
2. The total WPI was 10%.
3. He then turned to consider the other medical opinions and material before him and said:

"I note the report of Associate Prof Paul Minter, orthopaedic surgeon, dated 15 August 2024, described his opinion that there had been a good result of the left hip replacement procedure with 87 points and therefore a 15% whole person impairment. He found the same level of assessment in the right hip at 15% WPI. He deducted 50% of the impairment in the left hip due to pre-existing disease and a 100% with respect to the right hip, due to the fact there was no frank injury to that consequential condition.

Associate Prof Peter Papantoniou, in his report of 28 February 2024 opined a 50% WPI for the lumbar back and each hip joint, however no details as to the breakdown, between the back and each hip, were present in that report."

1. The Medical Assessor explained his reasons for the deductions he made as follows:

"In my opinion the worker suffers from the following relevant previous injuries, pre-existing conditions or abnormalities:

Long-standing and pre-existing osteoarthritis in the right hip joint which required a hip joint replacement procedure, in the absence of any work-related or frank injury.

Osteoarthritis of the left hip joint which required a hip joint replacement procedure after the aggravation sustained in the subject work-related incidents. It would be reasonable to consider 1/3 of the assessed impairment be deducted due to the underlying osteoarthritic condition.

There is also a significant previous history of a three-level lumbar disc injury from 1986, which resulted in a 5-year absence from work, and the radiological results available indicated significant long-standing and pre-existing degenerative changes in the lumbar spine, with no evidence of acute injury. In the absence of any frank injury, it would be appropriate to relate all of the current back condition to the pre-existing back condition and therefore there should be a 100% deduction of the assessed impairment level to take those pre-existing changes into account."

(a) the 100% deduction for pre-existing right hip injury relates to degenerative osteoarthritis, that the appellant was previously diagnosed with;

(b) the Medical Assessor should have taken into consideration that the appellant's osteoarthritis remained in stable condition and was instead aggravated during the subject accident. Therefore, the Medical Assessor should not have taken into consideration the Appellant's pre-existing osteoarthritis;

(c) the 100% deduction for a pre-existing/previous lumbar spine injury relates to an injury that the Appellant suffered in 1986;

(d) the Medical Assessor should have taken into consideration that the previous lumbar spine injury would have been substantially stabilised until the date of the subject accident. The appellant further claims that the degenerative changes were instead due to an aggravation to his lumbar spine injury, which was caused during the date of the subject accident, and

(e) this aggravation is argued on the basis that there was no formal claim made in relation to the deemed lumbar spine pre-injury in 1986. The lack of proper medical reports and complaints, other than the radiological reports available supports that the injury was not of a substantial nature.

(a) even if it is accepted that the appellant's osteoarthritis remained in a stable condition prior to the subject accident, this does not automatically mean that the pre-existing osteoarthritis did not contribute to the appellant's current impairment;

(b) the Medical Assessor must determine the proportion of the impairment that was due to the pre-existing condition. The Medical Assessor did this and the appellant has not provided a compelling basis for no deduction being made pursuant to

s 323 of the 1998 Act;

(c) the appellant has not addressed any evidence or basis for the contention that her [sic] prior lumbar spine injury had substantially stabilised until the subject work injury;

(d) even if it is accepted that the appellant's previous lumbar spine injury would have been substantially stabilised, this does not mean that the previous injury did not contribute to the appellant's current impairment (Vannini v Worldwide Demolitions Pty Ltd [2018] NSWCA 324);

(e) the Medical Assessor must determine the proportion of the impairment that was due to the pre existing condition. The Medical Assessor did this and the appellant has not provided a compelling basis for no deduction being made pursuant to s 323 of the 1998 Act;

(f) the appellant notes that the aggravation is argued on the basis that there was no formal claim made in relation to the deemed lumbar spine pre-injury in 1986. The appellant points to no medical evidence to support that the degenerative changes were caused during the date of the subject accident, and

(g) whether a formal claim was made in relation to the lumbar spine injury in 1986 is irrelevant. Section 323(1) of the 1998 Act will still apply.

"(1) In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality.

(2) If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence."

1. Cole v Wenaline Pty Ltd (2010) NSWSC 78 (Cole) is relevant authority for s 323 of the 1998 Act. It is noted that in order for a deduction to be made under s 323 there must be evidence that a pre-existing abnormality; condition; or previous injury contributes to the impairment.
2. In Fire & Rescue NSW v Clinen [2013] NSWSC 629, Campbell J referred to D'Aelo v Ambulance Service of New South Wales (1996) NSWCCR 139; Elcheikh v Diamond Formwork (NSW) Pty Ltd (in liq) [2013] NSWSC 365; and Cole, Campbell J said at [32]:

"As Schmidt J pointed out in Cole and Elcheikh, it is necessary to find a pre-existing abnormality or condition, here the latter, actually contributing to the impairment before s.323 WIM is engaged. This conclusion has to be supported by evidence to that effect. Assumption will not suffice."

"...necessary for the evidence acceptable to the appeal panel to actually support the connection between a previous injury (here, pre-existing abnormality or condition) and the overall degree of impairment in the instant case."

1. In Ryder v Sundance Bakehouse [2015] NSWSC 526 (Ryder), Campbell J said:

"What s.323 requires is an inquiry into whether there are other causes, (previous injury, or pre-existing abnormality), of an impairment caused by a work injury. A proportion of the impairment would be due to the pre-existing abnormality (even if that proportion cannot be precisely identified without difficulty or expense) only if it can be said that the pre-existing abnormality made a difference to the outcome in terms of degree of impairment resulting from the work injury."

1. A pre-existing condition or injury, even to the same body part, does not automatically invoke a deduction under s 323. The test is whether the pre-existing condition or injury actually contributes to the current impairment.
2. If the evidence does not establish that the previous injury contributes to the impairment, then no deduction can be made.
3. However, if the previous injury does contribute, even if it was asymptomatic at the time of the later injury, then there must be a deduction. (Vitaz v Westform (NSW) Pty Ltd [2011] NSWCA 254.)
4. To put it another way, we understand the Panel must be satisfied that but for the pre-existing abnormality, the degree of impairment resulting from the work injury would not have been as great.
5. In addition, the mechanism of injury (whether it be a frank injury, a disease injury or a consequential injury) is irrelevant when determining whether a deduction is required under s 323(1).
6. In this case, the starting point must be the terms of the referral.
7. It was clearly agreed between the parties that the appellant sustained injuries to his left lower extremity (knee and hip), his right lower extremity (hip) by way of a consequential injury, and his lumbar spine, also by way of a consequential injury. No challenge is made regarding the assessment of scarring.
8. Turning firstly to the left knee and hip, the Medical Assessor assessed 15% WPI as a result of the torn meniscus and extended tear. We agree with this primary assessment: it is consistent with the nature of the injury.
9. The radiological material indicates severe degenerative changes in the left knee and hip. Given the extent of those changes, we also agree that a one-third deduction was appropriate and consistent with the evidence.
10. Turning next to the right hip, the Medical Assessor also assessed 15% WPI, but deducted 100% in respect of the pre-existing condition.
11. The rationale for this deduction was not clearly explained.
12. The Medical Assessor said:

"The right hip had long-standing pre- existing degenerative osteoarthritic changes and subsequently required total knee joint replacement. He attributed the development of right hip pain to favouring of the left leg however there was no frank injury to the right hip (our emphasis)."

1. The Medical Assessor appears to have assumed that in the absence of a frank injury, a 100% deduction was appropriate.
2. Once again, as we said earlier, the mechanism of injury (whether it be a frank injury, a disease injury or a consequential injury) is irrelevant when determining whether a deduction is required under s 323(1).
3. Having carefully considered all of the evidence, we agree that a similar deduction is appropriate, namely one-third.
4. Turning lastly to the lumbar spine, the Medical Assessor assessed 5% WPI from which he deducted 100%.
5. There is no doubt that Mr Russo sustained a significant injury to his lumbar spine in 1986 which as the Medical Assessor noted "resulted in him remaining off work for a period of 5 years which apparently involved discs at 3 levels in the lumbar spine..."
6. However, he remained at work for a number of years thereafter.
7. Again, the terms of the referral noted an injury to the lumbar spine: the nature of the injury is irrelevant to the application of s 323.
8. The MRI in April 2022 noted "mild lower lumbar spondylosis."
9. The bone scan dated 5 February 2024 noted "Mildly active arthritic change again noted in the right sacroiliac joint."
10. We agree with the Medical Assessor's primary assessment in relation to the lumbar spine, but for reasons outlined above, the deduction is excessive.
11. We agree that some deduction is warranted, but in our view, having regard to the terms of s 323 and the various authorities to which we have referred, we are of the view that a one-fifth deduction is not at odds with the available evidence.
12. For these reasons, the Appeal Panel has determined that the MAC issued on

6 January 2025 should be revoked, and a new MAC should be issued. The new certificate is attached to this statement of reasons.

This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act 1998.

The Appeal Panel revokes the Medical Assessment Certificate of Medical Assessor Robin Alexander Mitchell, and issues this new Medical Assessment Certificate as to the matters set out in the table below:

Chapter, page and paragraph number in NSW workers compensation guidelines

Chapter, page, paragraph, figure and table numbers in AMA5 Guides

WPI deductions pursuant to s 323 for pre-existing injury, condition or abnormality (expressed as a fraction)

Sub-total/s % WPI (after any deductions in column 6)

Total % WPI (the Combined Table values of all sub-totals)