(a) this Certificate of Determination and Statement of Reasons;

(b) Application to Resolve a Dispute and attachments; and

(c) Reply and attachments.

A brief statement is attached setting out the Commission's reasons for the determination.

1. Dianne Badman (the applicant) was employed by the respondent, State of New South Wales (Sydney Local Health District) as an accounts-payable manager at Liverpool Hospital, and had been so employed since 2011.
2. On 20 February 2018, the applicant was walking from the main hospital at the respondent's premises back to her office when she tripped on uneven pavers and landed heavily on her right knee, right hand and face.
3. The applicant claims the cost of medical expenses pursuant to s 60 of the Workers' Compensation Act 1987 (the 1987 Act) including the costs of and incidental to a right total knee replacement and the cost of taxi fare for portions of her journey to and from work. She also claims permanent impairment compensation.
4. The fact of the injurious incident and the applicant's injury is not disputed, however, the respondent denies liability on the basis the effects of that injury had passed, and the requirement for the applicant's surgery and other s 60 expenses were brought about by the underlying pathology in her right knee, which is not compensable. There is no question the expenses claimed were objectively necessary. The question is whether they were necessary as a result of a work injury.

1. The substantive issue in dispute is whether the requirement for the applicant's surgery and her other medical expenses was brought about as a result of her injury. The parties agree that if this question is resolved in the respondent's favour, the applicant's claim for medical expenses will fail.
2. There is no question the treatment and expenses claimed by the applicant were reasonable. The question for determination is whether the requirement for them was brought about by the injury at issue, or by the underlying pathology I the right knee, which is not work-related.
3. The respondent submits if there is a finding in its favour, the applicant's claim for permanent impairment compensation would not be referred for medical assessment. The applicant disputes that assertion.
4. If the causation question is resolved in the applicant's favour, the parties agree not only will the medical expenses be paid, but the claim for permanent impairment will be remitted to the President for referral to her Medical Assessor to determine the applicant's degree of whole person impairment.

PROCEDURE BEFORE THE PERSONAL INJURY COMMISSION

1. I am satisfied that the parties to the dispute understand the nature of the application and the legal implications of any assertion made in the information supplied. I have used my best endeavours in attempting to bring the parties to the dispute to a settlement acceptable to all of them. I am satisfied that the parties have had sufficient opportunity to explore settlement and that they have been unable to reach an agreed resolution of the dispute.
2. The parties attended a hearing before me on 19 May 2025. Mr Parker of Counsel, instructed by Ms Nair, appeared for the applicant. Mr Baran of Counsel, instructed by Ms Ralph, appeared for the respondent.

1. The following documents were in evidence before the Person Injury Commission (Commission) and considered in making this determination:

(a) Application to Resolve a Dispute (Application), and

(b) Reply and attachments.

1. There was no oral evidence called at the hearing.

Whether the requirement for surgery was brought about by the work injury

1. The dispute in this matter being one of causation, the Commission is required to undertake a commonsense evaluation of the causal chain. That test was established by Kirby P (as he then was) in Kooragang Cement Pty Ltd v Bates (1994) 35 NSWLR 452 (Kooragang). In that matter, his Honour said:

"The result of the cases is that each case where causation is an issue in a worker's compensation claim, must be determined on its own facts. Whether death or incapacity results from a relevant work injury is a question of fact. The implantation of notions approximate cause by the use of the phrase 'results from' is not now accepted. By the same token, the mere proof that certain events occurred which predisposed a worker to subsequent death or injury will not, of itself, be sufficient to establish that such incapacity or death 'results from' a work injury. What is required is a common sense evaluation of the causal chain. As the early cases demonstrate, the mere passage of time between a work incident and subsequent incapacity or death, is not determinative of the entitlement to compensation."

1. There is no question the applicant suffered an injury to her right knee in the course of her employment. There is also no question she suffered from significant preexisting pathology. There is no issue the applicant previously suffered an injury to her right knee while working at the Sydney Children's Hospital prior to 1986. On that occasion, she slipped on stairs and struck her knee, suffering chipped cartilage. At that time, she did not submit a claim for her knee as she was not aware it was a compensable injury. The applicant states she had an arthroscopy in the early 1990s, with a good outcome from the surgery. She described having "occasional flareups of my knee" however, she stated this did not interfere with her ability to work.
2. During the course of the hearing, there was discussion surrounding the following aspect of the applicant's evidence:

"15. In around January 2018, I overused my knee and the pain flared up. I consulted my general practitioner and had a cortisone injection. The cortisone injection was very helpful and completely resolved my symptoms, although I did have some breathing difficulties. I was able to continue working and my knee remained asymptomatic until the fall on February 2018."

1. For the respondent, Mr Baran submitted this was plainly evidence which established a serious pre-existing pathology in the applicant's right knee which required treatment and caused her impairment very shortly before the injurious event at issue.
2. In a supplementary statement, the applicant noted she was mistaken about having a cortisone injection in January 2018. Rather, that injection took place in November 2017, and the applicant then had a further injection in April 2018, subsequent to the injury at issue.
3. For the applicant, Mr Parker submitted this evidence would be accepted, consistent as it is with an absence of any record of cortisone injection in January 2018 in the records of the applicant's longstanding general practitioner (GP) Dr Tattersall at Rozelle Medical Centre.
4. On balance, I find that evidence by the applicant persuasive. There is no suggestion that she consulted any GP other than Dr Tattersall over the course of many years, and there is no suggestion of any record from that practise demonstrating a cortisone injection in January 2018. Rather, it seems to me the applicant was plainly mistaken, having had an injection only two months earlier in November 2017.
5. Regardless of whether that injection took place in November 2017 or January 2018, it is apparent the applicant had sufficiently serious symptoms in her right knee to warrant consulting a general practitioner and having other treatment modalities carried out on it. What is in issue is whether the applicant's symptoms worsened after the relevant fall. In her initial statement, the applicant gave the following evidence surrounding her symptoms after the injury:

"7. An ambulance was called as I could not get up. I was taken to the emergency department for 11 hours and discharged later that night. My daughter picked me up and took me home. My knee was extremely swollen and I had a cast on my right wrist. My wrist was immobilised in case there was a fracture. I also had extensive bruising down my right leg.

1. Sometime later, an x-ray was taken in my right wrist which revealed a fracture, which was treated conservatively.
2. Following my injury, I was experiencing extreme pain in my right knee and right wrist, however, had to return to work as we were short staffed. My knee was extremely swollen, my leg completely bruised, and I was reliant on painkillers for both my wrist and my knee/leg. I was in a lot of pain but pushed through so I could support my team. Once the other staff returned to work, I took four to six weeks off work, as my knee and wrist pain worsened.
3. Eventually the bruising slowed down but the pain increased. I developed worsening pain below my knee and was walking with a limp. I became reliant on painkillers all of the time. My pain was worse at night when I lay down.
4. I attended by a general practitioner and had an MRI in April 2018. I was referred for physiotherapy, who performed some strengthening exercises and strapped my knee.
5. I was then referred to Dr Mark Horsley in or around September 2018, who recommended a total knee replacement surgery...
6. Prior to my injury on 20 February 2018, I was able to walk from Liverpool station to the hospital without any trouble. I am now unable to walk this distance and have had to take a taxi. The workers' compensation insurer was initially paying for my taxi and has stopped since declining my claim. My knee did not previously restrict my activities of daily living, and I was certainly not experiencing the same pain I am now."
7. The respondent contends the applicant would have come to the right total knee replacement surgery at or around the same time as it was eventually carried out, namely in April 2023, owing to the severity of the underlying pathology. Mr Baran submits that contention is supported by the views of Dr Horsley, who in his report to the applicant's GP dated

"An MRI scan demonstrates osteoarthritis in the medial and patellofemoral compartments of the knee. The only surgical procedure likely to help this knee is a knee replacement. I have discussed the surgery in detail including the risks and benefits."

1. Mr Baran submitted this is consistent with Dr Horsley stating the applicant's underlying pathology was the cause of the need for the knee replacement.
2. In a further report dated 17 October 2018 to the respondent's insurer, Dr Horsley was asked whether the knee replacement surgery would have been required in the future regardless of the injury at issue. Dr Horsley replied:

"It is likely that [the applicant] would require a knee replacement at some stage down the track regardless of whether she sustained the injury on 20 February 2018. It is possible that this injury has accelerated the requirement for surgery."

1. The respondent submitted this finding was consistent with the underlying pathology giving rise to the requirement for surgery. For the applicant, Mr Parker submitted it supported the contention that the effects of the underlying pathology had been accelerated, and as such, the injury was the cause of the requirement for the procedure.
2. The applicant relied on the report of occupational physician, Dr Wijetunga, dated 8 July 2024. That report was attacked by the respondent on the basis, in part, that Dr Wijetunga was not appropriately qualified to provide an opinion as she is not an orthopaedic surgeon, and the dispute at hand in this matter is purely orthopaedic in nature.
3. No objection was taken to Dr Wijetunga's report being entered into evidence, and the question is therefore one of the correct weight which ought to be attributed to it.
4. Dr Wijetunga's opinion was also criticised on the basis that he downplayed the applicant's past medical history. Dr Wijetunga's history in relation to the applicant's right knee was as follows:

"She reports previous injury to her right knee in the 1980s whilst at hospital where she was working upstairs and hit her knee on the concrete step which resulted in a laceration. She initially dismissed it but reports that it deteriorated over the next couple of years.

She consulted an orthopaedic surgeon about 10 years afterwards and underwent an arthroscopy from which she recovered well.

A few years following the arthroscopy, she experienced some intermittent pain in the joint which was estimated at 2-3/10. She was referred for physiotherapy and had some acupuncture which provided temporary relief.

She underwent four cortisone injections in total, the last of which was a couple of years before the subject accident. The cortisone injection provided some pain relief for about three months. However, after an onset of respiratory difficulties with cortisone injections, they ceased.

Her doctor recommended a further orthopaedic surgeon review which had not occurred since the arthroscopy. She consulted Dr Horsley, who recommended weight loss initially. However, she reports that despite walking about one kilometre each way to work for about five years, she was unsuccessful in weight loss.

It was noted that around November 2017, she had knee pain descending stairs, at which time she noticed some instability.

In the 12 months before the fall, she experienced intermittent knee pain which onset once every couple of months and on onset was about 3-4/10. At that point, she did not experience any locking or instability.

She was diagnosed with atrial fibrillation since 2007 and was commenced on medication including Micardis, Cristal, Sotalol and Nexium."

1. Mr Baran submitted Dr Wijetunga had downplayed the severity of the applicant's right knee symptoms, noting the records from the GP revealed some relatively consistent complaints over the months and years leading up to the injurious event at issue.
2. On balance, much of Dr Wijetunga's opinion is uncontroversial. He sets out the applicant's history but does seem to have erred in concluding the applicant was relatively unaffected by her right knee in the immediate lead up to the injury at issue. Dr Wijetunga described the applicant as being able to undertake all normal household activities and being actively involved in her hobbies of cooking and gardening. There is no evidence to contradict that conclusion on his behalf.
3. Dr Wijetunga also said there was no objective evidence of severe knee pain in or around early 2018 which interrupted the applicant in her work or home duties. With respect, this particular conclusion is not supported by the contemporaneous evidence, in that the applicant was consulting her general practitioner on a fairly regular basis concerning her right knee, and had in November 2017 (only 2-3 months before the injury at issue) undergone a further cortisone injection.
4. This being so, it cannot be said the applicant was asymptomatic before that issue.
5. However, that is not the end of the relevant factual inquiry. Whilst it is true the applicant suffered some right knee symptomology; she was plainly able to walk to and from Liverpool Hospital from the railway station in the course of her employment and was able to work regularly despite her pre-existing problems. That plainly changed after the injury at issue, at which time her symptoms became much worse and the effects of the underlying pathology in her knee worsened considerably.
6. In assessing injuries in the nature of an aggravation, it is important to note the injury consists only of the effects of the aggravation, not those of the underlying pathology. As Windeyer J noted in Federal Broom Co Pty Ltd v Semlitch [1964] HCA 34; (1964) 110 CLR 626 (Semlitch), the High Court's decision which was the genesis of existing authority in relation to such injuries:

"The question that each [injury in the nature of aggravation or acceleration] poses is, it seems to me, whether the disease has been made worse in the sense of more grave, more grievous or more serious in its effects upon the patient." (at 639) and in relation to whether there was an aggravation, His Honours said, "... The answer depends upon whether for the sufferer the consequences of his [sic] affliction have become more serious" (at 637).

"There is an exacerbation of a disease where the experience of the disease by the patient is increased or intensified by an increase or intensifying of symptoms. The word is directed to the individual and the effect of the disease upon him [sic] rather than being concerned with the underlying mechanism."

1. Semlitch has been followed consistently in this jurisdiction and its predecessors. For example, in Cant v Catholic Schools Office [2000] NSWCC 37 (Cant), Burke CCJ said:

"The thrust of these comments is that irrespective of whether the pathology has been accelerated, there is a relevant aggravation or exacerbation of the disease if the symptoms and restrictions emanating from it have increased and become more serious to the injured worker." (at [17])

1. Although Dr Horsley stated the applicant would likely have come to a total knee replacement in any event, his report concedes the possibility the injury at issue accelerated the need for that procedure. This contention is also advanced by the applicant's GP, Dr Tattersall, who has had the benefit of treating the applicant over many years. It is also supported by the applicant's independent medical examiners (IME), Dr Wijetunga and Dr Poplawski.
2. Dr Poplawski took a history relating to the applicant's past medical history which included the prior right knee injury, and when asked specifically whether the requirement for total knee replacement surgery was brought forward by the injurious event replied:

"I agree with Dr Horsley's statement that Ms Badman would ultimately require total knee replacement at some stage in the future. However, in my opinion, the injuries she sustained in the fall on 20 February 2018 have aggravated her symptoms to the point where she will require total knee replacement sooner rather than later."

1. In a second report dated 15 December 2020, Dr Poplawski maintained his view the applicant's employment with the respondent was the main contributing factors of the aggravation of her right knee. He stated it is more likely than not that had the applicant not sustained before at issue, she would not have required total knee replacement as soon as she did.
2. Dr Poplawski's view was opposed by the respondents IME, Dr Powell. Dr Powell was of the view the applicant's underlying pathology was the cause of the requirement for the total knee replacement surgery. Dr Powell provided four reports, in each of which he maintained the cause of the requirement for the surgery was the underlying pathology. In his last report, Dr Powell stated:

"For the reasons I have outlined in my previous reports, I believe the total knee replacement was required for the management of the pre-existing degenerative disease process.

I do not believe the subject workplace incident will be considered to represent the main contributing factor in the permanent aggravation of the pre-existing degenerative disease process and on that basis, there is no assessable permanent impairment."

1. The respondent submitted the aggravation caused by the injury at issue would have passed within 6-12 months of the applicants fall. In this regard, it is worth noting the applicant did not undergo the knee replacement until 2023. What is apparent from the lay and treating medical evidence, is the applicant's condition plainly worsened after the aggravating fall, and has not alleviated in the meantime. It must be remembered that symptomology rather than pathology is what gives rise to the requirement for treatment. For example, a patient may have serious underlying pathology in a given body system, however, it may remain asymptomatic until an aggravating event leads to the symptoms arising and worsening to the point that require treatment.
2. In the workers' compensation context, it is important to remember it is only necessary for a work injury to make a material contribution to the need for treatment. The authorities make this proposition clear. It is not necessary for the work injury to be the main contributing factor to the requirement for surgery, or even a significant contributing factor. Rather, the aggravation need only be one which makes a material contribution to the requirement for the treatment sought.
3. In this matter, having regard to the applicant's lay evidence in which she clearly sets out a severe worsening of her symptoms following the fall at issue which at no point alleviated before she had her surgery, the evidence of her treating general practitioner by way of both report and clinical records and the overwhelming IME evidence, I am satisfied on the balance of probabilities that the applicant's aggravation caused by the injury at issue continued until the point where she underwent the total knee replacement surgery.
4. It must be kept in mind that in circumstances where a party accepts an injury has taken place, but alleges its effects have passed, the onus of proof on that question resides with the party alleging the injury has resolved or its effects have ceased: see Commonwealth v Muratore [1978] HCA 47; (1978) 141 CLR 296; University of New South Wales v Brooks [2014] NSWWCCPD 68.
5. In this matter, having found the medical evidence discloses the effects of the aggravation were ongoing and being satisfied on the balance of probabilities the aggravation made a material contribution to the requirement for surgery, it follows I must also be satisfied that its effects were relevantly ongoing. This being the case, the total knee replacement surgery came about as a result of the applicant's work-related injury, and accordingly the respondent will be ordered to pay the costs of and incidental to it.
6. The applicant also made a claim for the cost of taxi fares between Liverpool railway station and the hospital said to have been incurred as a result of her injury. As with the surgery, there is no question the taxi rides were reasonable. The question is whether they were brought about by the injury. Having found the aggravation was ongoing, it follows there will be a finding in favour of the applicant to the effect the cab fares were reasonably necessary as a result of the injury at issue.

1. Having found the effects of the injury were ongoing and causative of the need for the knee replacement surgery, it follows the claim for permanent impairment compensation will be the subject of a referral for medical assessment. That outcome is not controversial, and the matter proceeded on this basis.
2. It may be, given the presence of pre-existing pathology in the relevant body system, that a deduction pursuant to s 323 of the Workplace Injury Management and Workers Compensation Act 1998 is appropriate, however, that is a matter within the provenance of a Medical Assessor, not a Member of the Commission.
3. This being so, the permanent impairment claim will be remitted to the President for referral to a Medical Assessor to determine the applicant's permanent impairment.

1. For the above reasons, the Commission will make the findings and orders set out on page 1 of the Certificate of Determination.