1. The applicant Mr Frank Pilsworth was employed by the respondent from 2000 carrying out maintenance and gardening work and later as a team leader mowing lawns.
2. The applicant's claim for a right knee injury on 19 October 2019 and right total knee replacement in March 2020 was accepted. He alleges he has also sustained a consequential left knee condition through avoiding putting pressure on his right leg and overcompensating with his left leg as a result of the accepted right knee injury and surgery.
3. A claim was made for left total knee arthroplasty recommended by the applicant's treating specialist Associate Professor Woodgate in 2022 and 2024.
4. The claim for total left knee arthroplasty was declined on 21 June 2022, 3 August 2022,

1 May 2024, following internal review on 20 December 2024 and again on 7 March 2025, on the basis that the applicant has not sustained an injury to his left knee, his employment was not a substantial contributing factor to his symptoms and there is therefore no entitlement to medical expenses. 5. The applicant lodged an Application to Resolve a Dispute (ARD) with the Personal Injury Commission (Commission) on 16 June 2025 claiming medical or related expenses for left total knee arthroplasty. 6. The dispute was listed for conciliation conference and arbitration hearing on 22 August 2025.

1. The parties agree the following issues remain in dispute:

(a) whether the applicant has sustained a consequential left knee condition as a result of the accepted right knee injury on 19 October 2019, and

(b) whether the applicant is entitled to the payment of reasonably necessary medical or related expenses of the total left knee arthroplasty proposed by Associate Professor Woodgate pursuant to s 60 of the Worker Compensation Act 1987 (1987 Act).

1. The parties appeared for conciliation conference and arbitration hearing on 22 August 2025 in Sydney. Mr Adel Salah of counsel appeared for the applicant instructed by Mr Steven Glavan, legal practitioner. Mr Daniel Stiles of counsel appeared for the respondent instructed by Ms Laura Beattie with Ms Saura, legal practitioners.
2. During conciliation the respondent's Application to Lodge Additional Documents dated

13 August 2025 was admitted. 3. I am satisfied 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 the parties have had sufficient opportunity to explore settlement and that they have been unable to reach an agreed resolution of the dispute.

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

(a) ARD and attached documents;

(b) Reply and attached documents, and

(c) respondent's Application to Lodge Additional Documents dated 13 August 2025 and attached documents.

1. No application was made to adduce oral evidence.

1. The applicant relies on his statement signed on 27 February 2025. He has been employed by the respondent since 2000, originally carrying out general maintenance and gardening work and later as team leader mowing lawns.
2. The applicant describes the accepted right knee injury on 19 October 2019 which led to right knee replacement surgery on 24 March 2020.
3. In the months leading up to the surgery the applicant avoided putting pressure on his right leg because of severe pain in his right knee and he overcompensated with his left leg, relying on his left leg to carry his weight when he walked. As a result of relying on his left leg he started to experience some pain in his left leg.
4. Following the right knee replacement in March 2020 the applicant was off work for about three months and attended physiotherapy. He continued to walk with a limp and avoided putting weight on his right leg, carrying his body weight on his left leg for an extended time to protect the injured knee and allow it to heal.
5. As a result he began to gradually develop increasing pain and stiffness in his left knee, symptoms that came on gradually over time. His doctors advised the applicant not to do any physical activity which would put strain on his right knee. He experienced great pain when pivoting or twisting under load and had great difficulty when transferring his weight.
6. The applicant continued to overcompensate with his left leg to avoid aggravating his right knee pain. As his left knee worsened Associate Profession Woodgate recommended a left knee arthroplasty in 2022 which the insurer declined. The applicant soldiered on hoping the pain would subside on its own.
7. Unfortunately it continued to deteriorate and the applicant approached Associate Professor Woodgate again in 2024 who requested approval for a total left knee arthroplasty. This was disputed and liability was declined.
8. The applicant would not have had to overcompensate with his left leg if not for the right knee injury. That injury is the reason he developed pain and symptoms in his left knee.
9. He has daily chronic pain, stiffness and restricted movement in his left knee, and pain in his right knee is increasing as he struggles to rely on his left knee due to pain.
10. In his supplementary statement dated 4 June 2025 the applicant describes his work duties before and after the right knee surgery in March 2020.
11. After the right knee injury in October 2019 the applicant returned to work on

2 December 2019, working from 7.00am to 4.00pm five days a week and completing the same duties as prior to his injury. He was not placed on light duties and his hours were not reduced. 12. His usual duties were mowing lawns sitting on a ride on lawn mower for about five hours a day, then whipper snipping for about two hours and using a leaf blower for about one hour. Sitting on the ride on mower meant his knees were in a bent position and his right knee became stiff and sore. Walking around to whipper snip and using the leaf blower after the ride on mower meant the applicant avoided putting weight on his sore right knee. He carried his weight on his left side, walking with a limp to give his right knee a break. 13. Following the right knee replacement in March 2020 the applicant returned to work on about 1 July 2020 completing the same duties. His shifts were reduced to four a week but now from 6.00am to 4.00pm. His request to spend the majority of his day on the ride on mower was accepted, however there were days when he had to also use the leaf blower. He was on his feet for about four hours when he did this, about once or twice a week, operating the leaf blower, picking up litter and ensuring the parks were tidy. 14. As he was still recovering from his right knee replacement he relied heavily on his left leg when walking and his left knee continued to further deteriorate. His hours were reduced in September 2024 as he turned 71 and he was offered a semi-retirement plan. He now works two days a week, still completing the 6.00am to 4.00pm shift with the same duties and spending most of his shift on the ride on mower. 15. Spending about nine hours a day sitting down with his legs bent has significantly impacted both the applicant's knees, and leaves him with constant pain and stiffness. His left knee has had increasing stiffness. During and after his shifts both knees feel sore, stiff and very swollen. He believes he was not given a proper opportunity to heal while still at work.

1. Dr Bodel reports on 10 December 2024 the applicant is developing increasing left knee pain that has come on gradually because of the abnormal gait pattern on the right knee over a prolonged period of time leading up to the right knee replacement.
2. Dr Bodel agrees with Dr Coolican who examined the applicant on behalf of the respondent that the cause of the pathology is multifactorial and there is constitutionally based arthritic change, however Dr Bodel's opinion is the injury is the aggravation to the disease process present in both knees caused by the applicant's work for the respondent since 2000.
3. The injury in October 2019 caused the aggravation, acceleration, exacerbation and deterioration to the right knee. The left knee symptoms came on gradually over time while favouring the left side while recovering from the right knee injury, the limp in the right leg and the postoperative management of the total knee replacement with the right knee.
4. Dr Bodel diagnoses post-traumatic osteoarthritis in both knees with the injury being the aggravation, acceleration, exacerbation and deterioration in the disease process, being the post-traumatic osteoarthritis in both knees.
5. The left knee is a consequential injury. By favouring the left leg for a period of time of some months while there was increasing limping in the right knee prior to surgery, and then in the early postoperative period after surgery. That has put an undue load on the abnormal left knee leading to the need for the knee replacement on the left side as well.
6. The left total knee replacement is reasonably necessary for the management of the consequential left knee injury following the original right knee injury in October 2019 in

Associate Professor Ian Woodgate, treating orthopaedic surgeon

1. The applicant consulted Associate Professor Woodgate about his right knee between February 2020 and April 2022. The right knee replacement and the applicant's recovery as well as his gradual return to work are documented in the reports.
2. In his report of 12 February 2020 Associate Professor Woodgate notes a mildly antalgic gait.
3. In the report of 4 April 2022, two years after the right total right knee arthroplasty, Associate Professor Woodgate notes of more concern recently is his contralateral left knee where he is developing some pain. X-rays show the left knee has more rapidly progressed to virtually bone-on-bone tricompartmental osteoarthritis.
4. Associate Professor Woodgate says:

"Clearly his left knee has more precociously failed, and this may be related to the period after his injury in October 2019 and subsequent right knee replacement in March 2020 where he became far more reliant on the left knee to take load. Therefore, there is a case that the left knee arthritis has been accelerated or deteriorated related to his index injury."[1]

1. The workers compensation provider would be approached to obtain consent to undergo a left total knee arthroplasty, hopefully relatively quickly as the applicant is developing increasing symptoms.
2. The request for consent for the proposed surgery was made on 4 April 2022.
3. Associate Professor Woodgate answered questions on 29 June 2022; the applicant's pain commenced in the left knee in about March 2022 and he had been reliant on the left leg whilst he had slow recovery and rehab at the right knee, referring to the applicant's altered gait pattern with increased load on his left leg and knee.
4. When Associate Professor Woodgate saw the applicant in March 2024, almost four years after the right knee arthroplasty, the left knee was not great. There was pain particularly with pivoting or twisting under load with some difficulty with transfers and discomfort on startup.
5. The doctor refers to a further request for approval of left knee surgery having been made on 21 November 2022 to which there had been no response.
6. Associate Professor Woodgate says he emphasised in his two letters the acceleration and deterioration of the left knee symptoms when the applicant was far more reliant on his left knee for a significant period of time following his right knee arthroplasty, and particularly because the applicant's generalised body rash and postoperative vertigo limited him in the early postoperative phase of the right knee procedure.
7. A request was made again for consent for staged left knee arthroplasty on 25 March 2024, which would hopefully be forthcoming promptly. The quotation is for surgeon's fees of $7,614 plus anaesthetist fees, and six nights' accommodation at East Sydney Private Hospital, prosthesis, theatre fee and associated costs during the admission, and five to six nights' accommodation at Wolper Rehabilitation Hospital at $864.10 a day.

1. The MRI right knee report of 3 December 2019 showed tricompartmental osteoarthritis with degenerative tearing and maceration of the medial meniscus.
2. The X-ray left knee report of 26 April 2023 refers to pain for more than one year and finds moderate to advanced osteoarthritic changes, near complete loss of joint space and mild degenerative changes at the patellofemoral joint.

1. The respondent relies on notices of 3 August 2022, 1 May 2024, 20 December 2024 and

17 March 2025 disputing liability for the requested surgical procedure, as it is not as a result of the applicant's employment with the respondent and is not considered a reasonably necessary medical expense.

Dr Myles Coolican, independent orthopaedic surgeon

1. On 26 May 2022 Dr Coolican reports on the development of gradual onset of left knee pain without any specific work injury. The applicant's gait across the office was normal.
2. The applicant is suffering from medial compartment osteoarthritis in the left knee, he needs to be very careful when he walks to avoid twisting and sudden unexpected movements and he struggles with stairs.
3. The cause of this is multifactorial in Dr Coolican's opinion, and in particular include a tendency to develop osteoarthritis as demonstrated by the osteoarthritis he developed in his right knee.
4. Dr Coolican's opinion is the development of osteoarthritis in the applicant's left knee and his current symptoms are unrelated to his right knee injury and surgery. There was no aggravation of the left knee as a consequence of the right total knee replacement, and if anything his left knee would have performed less standing and walking in the period when he was recovering from the surgery.
5. In relation to the proposed left knee surgery, Dr Coolican's opinion is the applicant is currently functioning satisfactorily with his left knee and is not yet ready for total knee replacement.
6. This surgery may be required at some stage in the future as the disease progresses but it is unrelated to the applicant's work and is a consequence of progressive osteoarthritis. When the left knee symptoms deteriorate knee replacement is likely to provide a significant improvement in the applicant's pain and function.
7. Non-operative treatment for the applicant's arthritic left knee includes weight loss, an exercise programme supervised by an exercise physiologist or physiotherapist to strengthen his quadriceps, hamstrings and gluteal muscles, use of a sleeve or unloader brace, regular Paracetamol and perhaps injections of steroids, PRP or hyaluronic acid into the knee, although the applicant will not be symptom free with ongoing non-operative treatment.
8. The applicant's symptoms will eventually deteriorate to the extent where he will eventually be unable to work and require a total knee replacement, however this is unrelated to his work.
9. On 1 July 2022 Dr Coolican comments on Associate Professor Woodgate's report of

29 June 2022. 10. Irrespective of a disparity in reported dates when the applicant first complained of left knee symptoms, Dr Coolican says there is no evidence that the applicant suffered any injury to his left knee in association with his work or that his symptoms were in any way a consequence of his right knee arthritis. 11. The applicant's delayed return to work following the right knee surgery would, if anything, reduce loads on the left knee. There is no evidence that patients recovering from knee replacement have added load to the contralateral limb. Their diminished activity level associated with joint replacement decreases the load on both limbs. 12. The applicant has bilateral osteoarthritis in the knees, more advanced on the right, when he suffered to injury in 2019. The MRI showed advanced medial compartment osteoarthritis in the right knee which clearly predated the 2019 injury. 13. Dr Coolican agrees with Associate Professor Woodgate that the applicant has osteoarthritis in the left knee and requires a left replacement in order to continue his work for the respondent, however this requirement is unrelated to any work injury or his work for the respondent. 14. The need for a total knee replacement is a result of the applicant's innate tendency to develop arthritis and is not a result of his work with the respondent. 15. On 1 May 2024 Dr Coolican confirms Associate Professor Woodgate's correspondence does not in any way alter his opinion concerning liability for the proposed left knee arthroplasty. 16. Whilst it may be appropriate to perform the surgery in Dr Coolican's opinion that requirement is unrelated to the right knee arthroplasty. 17. On 27 February 2025 following a re-examination of the applicant Dr Coolican comments on Dr Bodel's report of 10 December 2024. 18. The applicant described his left knee as asymptomatic to Dr Coolican until approximately one year after the right knee replacement. Dr Coolican did not describe the diagnosis of the applicant's right knee as post-traumatic osteoarthritis, and the arthritis is not post-traumatic. 19. Dr Coolican disagrees with Dr Bodel that the left knee arthroplasty is required because of added load to the left knee associated with osteoarthritis of the right knee. There is no evidence that osteoarthritis in one knee causes the contralateral knee to become arthritic because of overload. If anything the reduced level of activity has the effect of reducing rather than increasing the load on the nonaffected knee. 20. Associate Professor Woodgate's report of 25 March 2024 does not alter Dr Coolican's judgement that the requirement of the left knee arthroplasty in no way relates to the issues with his right knee. 21. The applicant has never suffered an injury or incident to the left knee which became symptomatic approximately 12 months after the right knee arthroplasty, after which there would have been a lesser rather than greater load on the left knee in the period after recovery.

Associate Professor Ian Woodgate, treating orthopaedic surgeon

1. The requests for surgery and quotation of 4 April 2022 and request for surgery of

25 March 2024 are relied on by the respondent, as well as Associate Professor Woodgate's reports discussed above.

1. Dr Bodel's report of 10 December 2024 is with the reply documents.

1. The MRI right knee dated 3 December 2019 is referred to above.
2. The X-ray right knee dated 30 April 2020 is post-surgery and describes the right knee prosthesis.

1. Dr Doig provides a report to the applicant's solicitors dated 11 May 2022.
2. Dr Doig reports the applicant experiences low grade discomfort while walking and negotiating stairs, particularly at the end of the day on his feet. He walked into the consulting rooms win no distress and with no evidence of a limp. There was no consequential condition to any other part of the body following the right knee injury, which was a symptomatic exacerbation and aggravation of pre-existing osteoarthritis affecting the right knee joint.
3. The applicant has returned to pre-injury hours and duties requiring some assistance from younger co-workers to perform some heavier tasks.
4. Dr Doig assesses 18% whole person impairment of the right knee.

Applicant's letter of instruction to Dr Hamann and annexures

1. The applicant's letter of instruction to Dr Hamann at Medicins Legale dated 1 February 2024 and annexures is regarding the applicant's skin condition following the right knee surgery, which is not the subject of these proceedings.

1. The clinical records of Ingleburn Medical and Dental, Ultra Care Medical Centre and Associate Professor Woodgate are with the reply and will not be considered unless the parties refer to them.
2. Professor Frankum's clinical records relate to treatment of the applicant for severe generalised dermatitis following right knee surgery, which is not the subject of these proceedings.

1. The applicant made oral submissions which have been recorded and form part of the Commission's record. These are set out below.
2. The applicant's right knee injury is accepted and a right total knee replacement took place on 24 March 2020. Thereafter the applicant developed progressive left knee symptoms and on

4 April 2022 his treating orthopaedic surgeon recommended a left total knee arthroscopy. That was disputed by the insurer. 3. The applicant did not press that and tried to push on until it came to the point where his symptoms were quite debilitating and he saw his orthopaedic surgeon again and that request was renewed on 25 March 2024 following conservative treatment. 4. The respondent issued dispute notices in 2022, 2024 and 2025 largely relying on

Dr Coolican's opinion. The overall premise is that respondent appears to have misapprehended the relevant test. The dispute notices essentially rely on ss 4 and 9A of the 1987 Act but in fact it is a consequential condition and all that is required is consideration of the authority of Kooragang[2] and Kumar,[3] that the left knee condition needs to result from the accepted right knee injury. 5. The respondent may take you to the MRI in 2014 which reports degenerative disease with an acute on chronic meniscal tear. The applicant submits that this is a baseline and not a bar to finding a consequential condition. 6. The 2023 X-ray documents end stage medial compartment osteoarthritis on the left knee consistent with the surgical plan. 7. The legal test relying on the test in Moon[4] and Kumar is that a consequential condition does not require the worker to prove a s 4 injury, the question is whether the later condition or treatment results from the accepted injury and it sequalae. In terms of Kooragang causation is assessed on commonsense practical grounds over the whole history. 8. The applicant's statement of 27 February 2025 describes the right knee injury, the right knee surgery and the post-operative skin condition for which liability has been accepted. 9. In relation to the left knee, the applicant's case is that following his total right knee replacement in 2020 he continued to walk with a limp and avoided putting weight on his right leg. He carried his body weight on his left leg for an extended period in order to protect his right knee and allow it to heal following surgery. 10. As a result he began to develop increasing pain and stiffness in his left knee. The management of his right knee after surgery meant he could no longer rely on it to complete daily tasks and fulfill his role at work. He continues to overcompensate with his left leg to avoid aggravating his right knee pain, and as his left leg began to worsen Associate Professor Woodgate recommended a left knee arthroplasty in 2022. That was declined. 11. A subsequent request was made when he could no longer handle the pain in 2024. 12. The applicant recommenced work five days a week from 7.00am to 4.00pm completing the same duties as prior to his injury, and he was not placed on light duties. Because of his operation of a ride on lawn mower he was seated in a bent position for a prolonged period and that caused his right knee to become stiff and sore. He also performed whipper snipper duties which was heavy in nature and required lots of walking, and there was an agreement with the employer that someone else would do that task. If that person was not available he was required to do that. 13. The applicant says that after his right knee replacement in March 2020 he returned to work full time from 1 July 2020 on reduced shifts of four days a week and increased hours from 6.00am to 4.00pm. His left knee felt increasing stiffness and started to trouble him, and after his shift both knees felt sore and very swollen. Those symptoms are consistent throughout the evidence. 14. The applicant did not report any knee problems to Associate Professor Woodgate in the over 10 years he has attended his practice before his right knee injury, and the doctor concludes that work has been a major precipitating factor in the exacerbation of the symptoms. 15. The report of 4 April 2022 (shown incorrectly as 4 April 2021) includes that the applicant occasionally has some variable swelling in the right knee. Of more concern recently is his contralateral left knee where he is developing some pain and the applicant is taking Voltaren as a result. On the 28 March 2022 X-ray the left knee has more rapidly progressed to virtually bone on bone tricompartmental osteoarthritis. 16. There was a pre-existing left knee condition but it has accelerated. 17. Associate Professor Woodgate says the left knee has precociously failed and this may be related to the period after his injury in October 2019 and subsequent to the right knee replacement in 2020. The respondent has placed heavy weight on the use of the word "may", but essentially he says the applicant became more reliant on the left knee to take load, and therefore there is a case that the left knee arthritis has accelerated or deteriorated related to his index injury. 18. That is when he made the request for the left total knee arthroplasty and he refers to the applicant developing increasing symptoms. 19. Associate Professor Woodgate's responses the insurer's questions were very supportive of the applicant. He directly attributes the left knee symptoms to the recovery of the right knee. The applicant had a slow return of right knee range post-surgery and returned to modified duties at six months. He had an altered gait pattern with increased load on the left leg/knee. 20. The applicant pushed through with the left knee pain as best he could but it came to a point in March 2024 when he had to see Associate Professor Woodgate. The doctor provides another report that is quite clear on the cause of the left knee symptoms. There is mild to moderate aches around the right knee and mild swelling but it does not limit his walking. He then says the left knee is not great and there is pain particularly on pivoting or twisting under load with some difficulty in transfers and discomfort on startup. 21. Reviewing some older X-rays Associate Professor Woodgate says they show virtually bone on bone medial osteoarthritis of the left knee, so there is evidence of pre-existing pathology. He says in his two letters he did emphasise the acceleration and deterioration of these symptoms. 22. The applicant was far more reliant on his left knee for a significant period of time following his right knee arthroplasty and particularly because the generalised body rash and post operative vertigo limited him in the early post operative phase of the right knee procedure. 23. The X-ray of 26 April 2023 relevantly includes clinical information that the applicant had left knee pain for more than one year. 24. The other radiology includes an X-ray of the left knee dated 21 August 2010 and clinical details include there is now pain in left lower leg and early degenerative change in the left knee but the investigation is for the history of tumour right tibia. 25. There is an X-ray of the right leg and left femur on 8 February 2013 requested by Associate Professor Woodgate in the additional documents, and again the clinical details section says previous tumour resection right lower leg, and incidental to that investigation mild medial tibiofemoral compartment osteoarthritis at the left knee was noted. 26. The MRI of the left knee on 13 May 2014 notes a history of acute on chronic meniscal tear and that was investigated. 27. A pre-existing left knee condition in 2014 does not defeat the consequential condition claim if the accepted right knee injury or the total knee replacement later aggravated or accelerated the left knee condition. 28. The applicant says this is exactly what the consequential condition covers on the Kooragang commonsense chain. 29. The meniscal tears and the medial compartment osteoarthritis often or usually co-travel and the 2014 acute tear sits within a degenerative knee. The applicant's case is not that there is no prior disease, but there is progression or acceleration to bone on bone identified in the 2023 MRI, years after the altered function. 30. Associate Professor Woodgate also mentions the acceleration component in his 2022 and 2024 reports. 31. The degenerative left knee changes in 2014 are the baseline and the accepted right knee injury or the total right knee replacement then accelerated the contralateral knee to bone on bone by 2023 and generated the left total knee arthroplasty recommendation in 2022 and 2024. 32. Dr Bodel notes increasing left knee pain which has come on gradually because of the abnormal gait pattern on the right knee over a prolonged period leading to the right knee replacement. 33. Dr Bodel notes the applicant walked with a mild left sided limp and when standing he could not fully extend the left knee. The active range of motion measured for the left side is quite similar to what Dr Coolican identified on his examination. 34. The symptoms on the left knee came on gradually while favouring the left side on recovering from the right knee injury in Dr Bodel's opinion. 35. The applicant agrees with Dr Coolican on the diagnosis not being post-traumatic osteoarthritis in the left knee as the symptoms came on gradually as Dr Bodel. 36. Dr Bodel then clarifies his opinion and says the injury is the aggravation, acceleration, exacerbation and deterioration of the disease process being post-traumatic osteoarthritis in both knees. His clear opinion is that the left knee condition is consequential and he acknowledges the recommended total knee replacement is reasonably necessary. 37. Dr Coolican takes a history that is consistent with Associate Professor Woodgate and

Dr Bodel. Dr Coolican's view is that the development of the osteoarthritis in the left knee is unrelated to the right knee injury and surgery however he does not grapple with the chronology of events. 38. Dr Coolican's rationale is essentially that the total right knee replacement would have slowed the applicant down, he would not have been walking as much and so the left knee symptoms would not have arisen as a result of not using it, but that is not the chronology of events. That is not the test we are considering today. 39. Dr Coolican asserts that because global activity fell the contralateral load must have fallen too. That is a generalisation. Low distribution can increase relatively on the contralateral knee despite fewer steps through altered gait, stance and stair negotiation. 40. Dr Coolican does not provide a rationale for his views when he gives his opinion that the requirement for left knee surgery is unrelated to the right knee arthroplasty and he leaves it at that. 41. There is no evidence that osteoarthritis in one knee causes the contralateral knee to become arthritic because of overload and that is essentially his rationale, but he does not grapple with the post-injury or post right knee surgery development of the left knee symptoms. He then accepts the proposed surgery is required but is not related to work. 42. If it is accepted that the left knee condition results from the accepted right knee injury then on Dr Coolican's own evidence the surgery is reasonably necessary.

1. The respondent made oral submissions which have been recorded and form part of the Commission's record. These are set out below.
2. The respondent agrees on the test for establishing a consequential condition but it is clear from the s 78 notices that the real issue in dispute is whether the need for left knee replacement surgery is a consequence of the accepted right knee injury.
3. Associate Professor Woodgate has not referred to any of the earlier investigations in his reports and opinions despite the fact he arranged for those investigations and at least two were provided to him.
4. The X-ray of 8 February 2013 was of the right leg and left femur and is clearly investigating some pathology in the right leg, however there are apparently no reports from Associate Professor Woodgate from around this point in time.
5. There is osteoarthritis in the left knee in 2013, six years prior to the subject incident. The

X-ray of the left femur in May 2014 appears to be looking at the whole left leg from the hip down but relevantly talks about the loss of joint space in the medial lateral foraminal compartments compatible with old trauma. There is evidence of pathology and old trauma in the left knee five years prior to the subject incident. 6. Associate Professor Woodgate's clinical records include an entry on 1 May 2014 of a few aches and niggles in the left knee, an MRI of the neck and left knee and physio for the neck and left shoulder, and on 28 May 2014 he notes an MRI of the neck/left knee. 7. This corresponds with the MRI of 13 May 2014 that indicates in addition to the reference of a history of degenerative disease and query acute on chronic meniscal tear, that there is pathology in the left knee consistent with degenerative disease. 8. What we do not have is any commentary from Associate Professor Woodgate on any of the reports in the application or reply of those investigations or scans. 9. The respondent accepts the statement that there are complaints of limping but there is nothing in the clinical material that corroborates that or is consistent with that. 10. It is clear the applicant manages to get back to work following his right knee injury and surgery. 11. The earliest investigation is the X-ray left knee on 28 March 2022 which says there are osteoarthritic changes in the left knee with joint compartment narrowing and osteophyte formation of the articular markings, and there are further degenerative changes of the patellofemoral joints and osteoarthritic changes of the tibiofemoral and fibular articulation. 12. The respondent submits this reads consistently with those investigations from 2013 and 2014, in that the changes are consistent with those earlier investigations. 13. Associate Professor Woodgate in his report of April 2022 refers to the X-ray of

28 March 2022 and its findings but he does not in this or in any other report comment back with reference to that earlier material. He is not saying there is evidence of a progression and he does not mention the earlier pathology. 14. In fairness he is a treating specialist and he does not have to do that, but he is not dealing with any issues of causation here or giving any explanation at this point, he is simply saying there is pathology in the left knee. He does not refer back to the pre-existing pathology in the knee that was clearly within his knowledge. 15. Dr Doig's medico-legal report contains an assessment of permanent impairment of the right knee. We know that when assessing impairment for a lump sum claim now it is your one claim so you need to be careful to ensure all of your body parts or injuries or conditions are included. 16. When dealing with the history in May 2022 Dr Doig says there are no consequential conditions, and when he is asked fairly and squarely again he says there are no consequential conditions to any other part of his body system, and this is three years post-surgery. 17. The lump sum claim was not proceeded with however Dr Doig makes it clear in May 2022 that there are no consequential conditions of any kind. 18. In Dr Coolican's first report of 26 May 2022 he accepts there is medial compartment osteoarthritis in the left knee and the cause is multifactorial. Dr Coolican accepts the right knee osteoarthritis was exacerbated by the discrete injury in 2019 and says the left knee osteoarthritis has progressed over time and is unrelated, which the respondent says is consistent with the 2013 and 2014 scans. 19. Dr Coolican says no injury was suffered to the left knee in the past. The respondent's submission is that this is not necessarily conceded as the earlier scans refer to old trauma however that cannot be taken further because there is no other evidence to suggest there was old trauma or where that comment comes from. 20. Dr Coolican does not consider there was an aggravation to the left knee as a consequence of the right knee replacement and he comments on the reduced activity following that surgery. The applicant's current symptoms do not warrant the proposed left knee surgery at this point in time. 21. In Dr Coolican's report of July 2022 there is a query about when the applicant first complained of left knee symptoms which Associate Professor Woodgate dates as from March 2022 and the applicant indicated to Dr Coolican began in March 2021. 22. Looking at the clinical material we now have but which Dr Coolican did not have the benefit of at the time of this report, we can see there is evidence of at least some left knee symptoms going back to 2014 which warranted the MRI scan being undertaken. 23. Dr Coolican agrees the osteoarthritis now warrants surgical intervention but maintains it is unrelated to the right knee work injury. 24. In Associate Professor Woodgate's report of 25 March 2024, four years post-surgery, he maintains his earlier opinion the left knee is not great, refers to the X-ray of 2023 but still does not refer to any of the earlier history of scans or causation at all. 25. Dr Coolican in May 2024 simply reiterates his earlier opinion that surgery is warranted but unrelated to the accepted right knee injury or surgery. 26. Dr Bodel in December 2024 does not seem to have looked at any X-rays or investigations at all and certainly not the 2013 or 2014 scans. Dr Bodel accepts constitutionally based changes however he finds aggravation of disease in both knees. 27. Dr Bodel comments that the applicant's work requires a lot of kneeling and squatting, climbing, getting on and off pieces of machinery and general labouring activities, and this type of work has caused the aggravation to both knees. This suggests a nature and conditions type of cause of knee symptoms and pathology but does not seem consistent with what the applicant now asserts. 28. The applicant's statement evidence is that when he went back to work he was working more on the ride on mower and occasionally used the leaf blower and that seems quite a bit different to the history recorded by Dr Bodel talking about kneeling, squatting, climbing and so forth. 29. Dr Bodel nevertheless diagnoses port-traumatic osteoarthritis in both knees and the applicant fairly concedes the left knee is not post-traumatic. 30. The respondent's general observation about Dr Bodel's opinion is that he has not had the benefit of the earlier investigations or review of any of the investigations. He does not have a history of knee problems going back to 2014 and he does not accurately record the applicant's post-injury and post-surgery duties consistent with what the applicant now says in his statement evidence. 31. The respondent's submission is you would give little weight to Dr Bodel's opinion on those points. 32. Dr Coolican's final report of 27 February 2025 deals with Dr Bodel's opinion. Dr Coolican again reiterates his comments about the activity level post-injury and post-surgery suggesting it would be reduced or lesser. The respondent submits this is consistent with the applicant's statement evidence that he was doing reduced hours at times and reduced days and the nature of his duties were restricted to using the ride on mower and occasionally using the leaf blower, and is certainly not consistent with what Dr Bodel was referring to. 33. Dr Coolican again says the left knee surgery is needed but not as a consequence of the subject incident or the right knee replacement surgery, and again that there would have been lesser rather than greater load for the period he was recovering from the surgery. 34. The onus is on the applicant to establish the consequential condition and in doing that he relies on the opinions of the treating specialist Associate Professor Woodgate and Dr Bodel. 35. The respondent's submission is that both of those opinions fall short because they do not refer to the history, and Dr Bodel does not seem to have it at all. 36. In the context of a case where it is clear the applicant had long standing problems with his knee with changes in his knee pathology going back well prior to the subject incident, the fact that neither the specialist or Dr Bodel have taken it on board and dealt with it and said despite that evidence we accept and exacerbation or aggravation or something has occurred that has progressed to the need for the replacement surgery, you would accept Dr Coolican's opinion that ultimately he was always going to come to this need for a knee replacement, probably in both knees given the pathology, the right knee brought forward by the subject incident. 37. You would not be satisfied that there has been any material contribution to the need for that surgery as a result of either the post-injury or post-surgery period of work with the respondent, and an award would be entered in favour of the respondent in relation to the claim for proposed surgery and the respondent submits in respect of the allegation of a consequential left knee condition.

1. The respondent's case largely hinges on the fact that there is an MRI scan back in 2014 which was not referred to by Associate Professor Woodgate who requested it, or by

Dr Bodel. 2. There is no dispute there was pathology in the past, there is a pre-existing condition and that is the baseline, that is the state the applicant's left knee was in. The question is what is the cause of deterioration up to the point that he now needs a total left knee replacement. 3. Other than the clinical record in May 2014 and the subsequent record which refers to a few aches and a few niggles, that is the extent of the pre-existing complaints the applicant has made. There is nothing following that to show he has had left knee problems. It has been largely asymptomatic until after the right total knee replacement and that is because he used the left knee after the right knee injury and more so after the surgery to avoid use of the right knee post-surgery. 4. The reason for the MRI in 2013 is the tumour resection right lower leg and the history does not include left leg pain. The reason for that scan is the same as for the 2010 X-ray which is the previous tumour resection in the right lower leg which caused left leg pain, and not because of any left knee symptomatology. 5. Associate Professor Woodgate does not mention the 2014 MRI and the applicant's submission is that is simply because, as he recorded, there were a few aches and niggles. It would be fair to accept that there were no subsequent complaints, and this is why he says in his report that the applicant has attended his practice for well over 10 years and he has never previously documented any knee injury. 6. Dr Bodel does not reference the investigations however he was privy to all of Associate Professor Woodgate's reports that do reference the investigation findings so the applicant submits Dr Bodel's opinion holds significant weight along with Associate Professor Woodgate who has treated the applicant for the last 10 years.

Did the applicant sustain a consequential left knee condition as a result of the accepted right knee injury on 19 October 2019

1. The applicant carries the onus of establishing he has sustained a consequential left knee condition on the balance of probabilities, and he must actually persuade the Commission of the occurrence or existence of a fact before it can be found.[5]
2. As the parties agree, it is not necessary for the applicant to establish a consequential injury to his left knee is itself an 'injury' pursuant to ss 4 and 9A of the 1987 Act. As Deputy President Roche discusses in Moon, all the applicant must establish is that the symptoms and restrictions in his left knee have resulted from his right knee injury.
3. Where there is a consequential condition the legal test of causation requires the application of the principles in Kooragang, confirmed in Kumar, with each case determined on its own facts and on the basis of the evidence and expert opinions.
4. The question to be asked is whether the disputed incapacity resulted from the work injury,[6] and whether the subject injury materially contributed to the onset of the condition claimed, unbroken by a novus actus interveniens.[7]
5. The applicant's statement evidence is that as a result of the right knee injury in October 2019 he avoided putting pressure on his right leg, relied on his left leg to carry his weight when he walked and began to experience left knee pain. He returned to work full time work in December 2019 carrying out his usual duties, including mowing lawns on a ride on mower when his knees were in a bent position, whipper snipping and leaf blowing. He walked with a limp, carrying his weight on his left side to give his right knee a break.
6. After the right knee surgery in March 2020 the applicant did not work for about three months and he continued to walk with a limp, avoiding putting weight on his right leg to protect the right knee. Pain and stiffness gradually developed in his left knee as a result. He returned to work in about July 2020 completing the same duties over four days a week but starting one hour earlier each day. He was able to spend the majority of time on the ride on mower and about once or twice a week he operated the leaf blower when he was on his feet for about four hours. His left knee deteriorated. The applicant's hours were reduced in

September 2024. 7. Associate Professor Woodgate has treated the applicant for more than 10 years. The first report in which he refers to the applicant's left knee symptoms is in April 2022 where he notes the left knee has more rapidly progressed to virtually bone on bone tricompartmental osteoarthritis. He concludes the left knee arthritis has been accelerated or deteriorated related to the index right knee injury, emphasising the acceleration and deterioration of the left knee symptoms. 8. The respondent refers to Associate Professor Woodgate's clinical notes on 1 May 2014 which include "[f]ew aches L knee" and "few niggles L knee", and on 28 May 2014 which include a reference to an MRI of the neck and left knee.[8] There appear to be no further references to the applicant having left knee symptoms until Associate Professor Woodgate's report of April 2022 as the applicant submits. 9. The 2013 X-ray left femur report refers to mild degenerative changes and the X-ray left femur report of 1 May 2014 includes a reference to loss of joint space in two compartments. The MRI left knee report dated 15 May 2014 includes a reference to tearing in the posterior horn of the medial meniscus. While he did not refer to these in his recent reports, these investigations appear in Associate Professor Woodgate's clinical records and having been requested by him he is necessarily aware of them. These did not lead him to opine that the left knee symptoms are a natural progression of the pre-existing degenerative disease. 10. I accept Associate Professor Woodgate's explanation that the rapid progression or acceleration and deterioration in the applicant's left knee symptoms result from an altered gait pattern with increased load on the left leg and knee following the right knee injury and surgery. 11. Dr Bodel addresses the test set out in Moon describing the applicant's symptoms and restrictions in his left knee as resulting from his right knee injury and surgery, with an altered gait pattern over a prolonged period of time leading up to the March 2020 right knee surgery. Dr Bodel agrees there is constitutionally based arthritic change in the left knee, however favouring the left side while recovering from the right knee injury and surgery with the limp putting undue load on the abnormal left knee has led to the need for left knee surgery. 12. I do not agree with the respondent's submission that little weight ought to be afforded to

Dr Bodel's opinion as he has not had the benefit of the investigations and the history of left knee problems from at least 2014. Dr Bodel refers to the reports of Dr Coolican and Associate Professor Woodgate which in turn refer to investigations following the right knee injury in 2019. 13. It is difficult to accept that Dr Bodel's opinion would have been significantly altered if he had the benefit of considering the 2103 and 2014 investigation reports given that his opinion in any event is that the applicant has a pre-existing left knee osteoarthritis condition. 14. While tearing of the medial meniscus was also shown on the 2014 MRI, as the applicant submits there do not appear to have been complaints made or treatment provided in relation to the applicant's left knee from 2014 until sometime after the right knee injury, which Associate Professor Woodgate's reports confirm. 15. The respondent also submits Dr Bodel does not accurately record the applicant's post-injury and post-surgery duties consistently with the applicant's statement evidence. 16. Dr Bodel lists the applicant's work activities as involving a lot of kneeling and squatting, climbing, getting on and off pieces of machinery and general labouring activities. This is consistent with the applicant's statement evidence prior to the total right knee replacement. Following surgery in March 2020 the applicant says he continued to use the ride on mower, necessarily involving climbing and getting on and off machinery, and he spent about four hours a week on his feet doing the leaf blowing, including picking up litter and ensuring the parks were tidy. This would appear to encompass kneeling, squatting and general labouring duties. 17. In these circumstances I do not accept Dr Bodel's description of the applicant's work duties is so different from the applicant's statement evidence that his opinion ought to be afforded less weight as a result. 18. I prefer Dr Bodel's opinion to that of Dr Coolican. 19. In Dr Coolican's opinion there would have been less activity overall following the applicant's right knee injury and surgery. If anything the applicant would have performed less standing and walking when he was recovering from the right knee surgery in Dr Coolican's opinion, and a diminished activity level decreases the load on both limbs. The applicant would have had a lesser rather than greater load on his left knee in the period after recovery from the surgery. 20. This opinion does not accord with the applicant's evidence. The applicant's statement evidence is that he avoided placing pressure on his right leg due to severe pain and relied on his left leg as a result. He returned to work full time on 2 December 2019 carrying out his usual duties, six weeks after the right knee injury. Following the right total knee replacement on 24 March 2020 the applicant returned to work on about 1 July 2020, about 14 weeks after the surgery, initially for three days a week for four hours a day,[9] increasing to four days a week and 10 hours a day by about March 2021.[10] 21. I do not accept the evidence supports a conclusion that the applicant had a lesser load on his left knee following the right knee injury and recovery from the right knee surgery, even while he worked reduced hours and with changed duties. Aside from his work activities, the applicant's statement evidence is that he also struggles to rely on his left knee for support or to carry him through day-to-day activities. 22. Dr Coolican states there is no evidence that patients recovering from knee replacement have added load to the contralateral load. This does not accord with the applicant's statement evidence or the expert opinions of Associate Professor Woodgate and Dr Bodel in this case. 23. I afford this opinion less weight as a result. 24. I note the respondent accepts the applicant's statement evidence of complaints of limping although notes there is nothing in the clinical material that corroborates or is consistent with that. 25. In April 2022 Associate Professor Woodgate refers to far more reliance on the left knee to take load following the right knee injury and surgery, although by 2024 the applicant's gait is essentially normal. Dr Doig reports there was no evidence of a limp in May 2022. Dr Coolican examines the applicant in 2023 and reports his gait across the office is normal. Dr Bodel says the applicant had months of walking with a limp and an abnormal gait pattern over a prolonged period before the right knee surgery and in the early postoperative period. I accept the applicant's statement evidence and I am persuaded on a commonsense evaluation of the causal chain that the applicant was required to place more load on his left knee as a result of his right knee injury and surgery. 26. Dr Doig's opinion in May 2022 that there is no consequential condition is formed in the context of not finding the applicant has a left knee condition. As this is anomalous with the other evidence I afford this opinion little weight. 27. On a consideration of all of the evidence including expert opinions I find the applicant sustained a consequential left knee condition as a result of the accepted right knee injury on 19 October 2019.

Is the proposed total left knee arthroplasty reasonably necessary as a result of the injury

1. Section 60 of the 1987 Act provides that if as a result of an injury received by the applicant it is reasonably necessary that any medical or hospital treatment be given, the respondent is liable to pay for that treatment or service.
2. The legal test when determining whether proposed treatment is reasonably necessary as a result of a workplace injury was considered by Roche DP in Diab v NRMA Limited;[11] reasonably necessary does not mean absolutely necessary, and the applicant has to establish that the treatment claimed is one of what may be a range of different treatments that qualifies as reasonably necessary in the circumstances. Useful heads of consideration are confirmed in Diab although the essential question remains whether the treatment is reasonably necessary.
3. There is no dispute that the proposed surgery is reasonably necessary. The evidence of Associate Professor Woodgate and Dr Bodel is that the proposed total left knee arthroplasty is reasonably necessary, and as the respondent acknowledges Dr Coolican accepts the applicant now requires left total knee replacement.
4. As I have found the applicant sustained a consequential left knee condition as a result of the accepted right knee injury on 19 October 2019, the proposed left total knee arthroplasty is a reasonably necessary medical or related expense resulting from the left knee condition.
5. The applicant is entitled to the payment of the costs of the left total knee arthroplasty proposed by Associate Professor Woodgate on 25 March 2024.

1. The applicant sustained a consequential left knee condition as a result of the accepted right knee injury on 19 October 2019.
2. The applicant is entitled to payment of the costs of the left total knee arthroplasty proposed by Associate Professor Woodgate pursuant to s 60 of the 1987 Act.
3. There will be an order that the respondent is to pay the costs of and incidental to the left total knee arthroplasty proposed by Associate Professor Woodgate at the appropriate SIRA gazetted rates.

[2] Kooragang Cement Pty Ltd v Bates (1994) 35 NSWLR 452; (1994) 10 NSWCCR 796 (Kooragang).

[3] Kumar v Royal Comfort Bedding [2012] NSWWCCPD 8 (Kumar).

[4] _Moon v Conmah Pty Limit_ed [2009] NSWWCPD 134 (Moon).

[5] Nguyen v Cosmopolitan Homes [2008] NSWCA 246 at [55].

[7] Secretary, New South Wales Department of Education v Johnson [2019] NSWCA 321 at [53].

[11] [2014] NSWWCCPD 72 at [86] (Diab).