1. On 22 January 2025 David John Gentle, the appellant, lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Roger Pillemer, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on

14 January 2025. 2. The appellant relies on the following grounds for appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act): * the assessment was made on the basis of incorrect criteria, and * 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 appellant commenced employment on 22 July 2015 with Civilnett Pty Ltd, the respondent, working as a plumber, gas fitter and roofer. He was at that time 47 years of age.
2. In a statement the appellant signed on 18 August 2022 he details at paragraph 21 the tasks he performed for the respondent. It is fair to say that what he describes therein reveals that his work was arduous and heavy. Some of the tasks he did included carrying water systems weighing between 25 and 100kg, walking up and down ladders, climbing to and working within confined spaces such as roof cavities and under floors, moving and stacking timber weighing between 1kg and 20kg, lifting, carrying and laying water mains weighing between 20 and 50kg, using a "whacker packer" to compact trenchers, and lifting and fitting and cutting concrete stormwater pipes that could weigh up to 2.8 tonnes and which he had to push using crowbars. Further, in a report that orthopaedic surgeon Dr A. G. Hopcroft provided to the appellant's solicitors on 28 September 2022, Dr Hopcroft noted that the appellant used his right and left feet to push piles of blue metal backwards and forwards in order to level the pile of blue metal.
3. The Appeal Panel notes that the appellant's solicitors qualified Dr Hopcroft to examine the appellant on various occasions and to provide reports to them relating to the symptoms the appellant suffers in his lumbar spine and hips and the relationship of those to the appellant's employment with the respondent.
4. In his statement of 18 August 2022 the appellant describes that on 21 August 2020 he was preparing trenches and laying pipes on a particular job. One pipe weighed 2.8 tonnes. As he pushed this pipe into place he felt pain in his lower back radiating down his legs. Soon after that incident he developed discomfort in both his hip regions.
5. The symptoms prompted him to seek treatment from his general practitioner. Several investigations have been done since then. His symptoms were initially treated conservatively, but ultimately on 1 July 2021 he had a left hip replacement followed by a right hip replacement on 1 December 2023.
6. As far as the Appeal Panel can tell from the evidence before it, it seems the appellant did not work between 21 August 2020 and September 2021, when he then returned to his employment but his duties were limited to driving machinery. It seems at some point in 2022 he again ceased work and has not returned.
7. On 20 May 2024 the appellant's solicitors wrote to the respondent's insurer advising them that the appellant claimed compensation under s 66 of the Workers' Compensation Act 1987 (the 1987 Act) for permanent impairment from injuries to his lumbar spine and right and left hips. They advised the degree of the appellant's permanent impairment from these injuries was of the order of 35% whole person impairment (WPI). They provided with their correspondence copies of reports of Dr Hopcroft dated 24 April 2024 and 17 May 2024.
8. In his report of 24 April 2024 Dr Hopcroft advised that he assessed the degree of the appellant's permanent impairment from the injuries to his hips and lumbar spine was 30% WPI. That was a combination of 5% WPI he assessed the appellant had relating to his lumbar spine, 14% WPI he assessed the appellant had with respect to his left hip, and 14% WPI he assessed the appellant had with respect to his right hip. Dr Hopcroft in that report said he assessed the appellant had no impairment relating to scarring because his scars are disappearing and hidden under clothing and do not have symptoms.
9. In his subsequent report Dr Hopcroft revised his assessment of the appellant's permanent impairment relating to the right hip 18% WPI. He also advised that the appellant "accrues a further whole person impairment of 1% (with longitudinal scars on the anterior aspect of both knees and classic lateral numbness)". Dr Hopcroft added 1% WPI for "each knee" and he combined that with the other impairments he assessed the appellant had such that his revised assessment of the appellant's overall WPI amounted to 35%.
10. For the completeness the Appeal Panel notes that paragraph 14.5 of the Guidelines stipulates that the skin is regarded as a single organ and one overall impairment it is to be assessed for it rather than assessing individual scars separately and combining the results. Thus, Dr Hopcroft ought to have assessed the appellant's degree of permanent impairment as being 34% WPI. Even if he had assessed the appellant's permanent impairment relating to scaring as 1% or 2% WPI, because the appellant's skin is to be treated as one organ, either of those assessments when combined with 33% WPI produces 34% WPI.
11. Following receipt of the appellant's claim, the respondent's solicitors arranged for the appellant to be examined by orthopaedic surgeon Dr Anil Nair on 1 August 2024. In a report dated 9 August 2024 Dr Nair advised he assessed the degree of the appellant's permanent impairment from his injury is 27% WPI. That assessment was a combination of his assessments of the appellant's impairments of his right and left hips and lumbar spine. With respect to the appellant's left and right hips, Dr Nair assessed the appellant 14% WPI for each hip which was the net result after making a deduction for what Dr Nair described as pre-existing osteoarthritis. His assessment relating to the appellant's lumbar spine was 5% WPI. Dr Nair combined 14% with 14% and 5% to reach 30% WPI. He then made a further 1/10th deduction so as to assess the appellant's impairment is 27% WPI. It is immediately apparent that Dr Nair mistakenly made a deduction twice, rather than once, for what he considered was pre-existing osteoarthritis in the appellant's hips. He subsequently corrected that error in a report dated 14 October 2024, revising his assessment to 30% WPI.
12. On 2 October 2024 the respondent's solicitors wrote to the appellant's solicitors advising them that the respondent's insurer offered to settle the appellant's claim for compensation under s 66 by paying him compensation for 27% WPI. It provided with its correspondence a copy of Dr Nair's report of 9 August 2024. Following that, the appellant initiated proceedings in the Personal Injury Commission (Commission) by filing with it an Application to Resolve a Dispute dated 20 September 2024. The respondent filed a reply to that and, following that, the matter was referred to a Commission Member Carolyn Rimmer, who on

28 October 2024, with the consent of both parties, noted that the appellant withdrew his claim for compensation for permanent impairment relating to scarring and remitted the balance of the appellant's claim to the President of the Commission so it could be referred to a Medical Assessor to assess the degree of the appellant's permanent impairment from his injury to his lumbar spine and left hip and right hip. 13. The Medical Assessor examined the appellant on 13 January 2025 to conduct that assessment and, as said above, on 14 January 2025 issued the MAC. 14. The Medical Assessor recorded in the history he detailed in the MAC that the appellant had no "problems prior to the onset of symptoms in August 2020 and has not had any further injury since then". The Medical Assessor recorded that the appellant had "a number of unrelated accidents and injuries, including to his left ankle, right shoulder, carpal tunnels and right tibial plateau fracture". 15. The Medical Assessor recorded the following regarding the appellant's capacity with his social activities and activities of daily living:

"He feels he could walk for say 3 to 4 kilometres at this stage and then his hips might start to worry him. His maximum driving time would be a couple of hours because of discomfort in his low back. He is able to help with the housework but does have some difficulty for example making beds, and he says he could carry a carton of beer at this stage but He still does the mowing on the property as noted but would have to do this

He occasionally has difficulty with shoes and socks but he feels that he needs to continue doing this as it is good exercise."

1. The Medical Assessor noted from the reports on the various investigations the appellant has had done of his hips that the investigations showed evidence of "advanced osteoarthritic change" in the appellant's hips. The Medical Assessor also noted that a MRI of the appellant's lumbar spine done on 27 October 2020 showed "degenerative changes at the lower two lumbar levels with disc bulging and facet arthropathy and foraminal stenosis at L5/S1 with a suggestion of contact with L5 nerve root".
2. The Medical Assessor considered that the appellant's lumbar spine correlated with the criteria for DRE Category II. That is not the subject of any controversy in the appellant's appeal against the medical assessment. That allowed for a permanent impairment to be assessed within the range of 5% - 8% WPI, depending on the effect the appellant's injury had on his activities of daily living. With respect to that the Medical Assessor added 1% WPI explaining that the appellant is "still fairly active but is restricted with activities such as gardening and carrying cartons of beer". The appellant takes issue in his appeal with the Medical Assessor adding only 1% WPI.
3. That brought the appellant's overall permanent impairment relating to his back to 6% WPI, from which the Medical Assessor deducted 1/10th "noting the extensive degenerative change in the lumbar region". Hence, the Medical Assessor assessed the degree of the appellant's permanent impairment relating to his lumbar spine from the injury he suffered due to his work with the respondent was 5% WPI.
4. The appellant has also has taken issue with the deduction the Medical Assessor made under s 323(1) of the 1998 Act.
5. The Medical Assessor assessed that the appellant had a degree of permanent impairment relating to each hip of 15% WPI, on the basis that the appellant had achieve a good result from his hip replacement surgery. The appellant does not take issue with that assessment in his appeal.
6. The Medical Assessor also made a deduction from that assessment of 1/5th for a proportion of that permanent impairment that the Medical Assessor considered was due to "constitutional osteoarthritis" in the appellant's hips, such that the Medical Assessor assessed the degree of the appellant's permanent impairment of each hip resulting from his injury is 12% WPI. The appellant also takes issues with the deduction the Medical Assessor made relating to his hips.
7. With respect to the deduction the Medical Assessor made under s 323(1) for the proportion of the appellant's permanent impairment relating to his hips that he considered was due to a pre-existing condition the Medical Assessor provided the following explanation in part 11 of the MAC:

"Please note that the diagnosis of Mr Gentle's hip problems is one of constitutional idiopathic osteoarthritis of both hips, noting the absence of any particular injury, and the onset of problems bilaterally with a typical presentation of constitutional arthritis. I would certainly accept that the nature and conditions of his employment would have aggravated any underlying constitutional condition.

In my opinion the aggravation of his underlying osteoarthritic condition would not have been the cause for his need for his hip replacements but would certainly have brought on the need for these earlier than might otherwise have been the case.

I would suggest that it was inevitable that he would eventually have required bilateral hip replacements irrespective of the nature and conditions of his employment.

As noted, Mr Gentle's initial treating specialist indicated that he had placed Mr Gentle on the public hospital waiting list, indicating that in his opinion Mr Gentle's hip problems were not work-related.

I note that it might be suggested that Mr Gentle did not have any problems with his hips before joining Civilnett Pty Ltd, but this is a legal and not a medical concept.

With regard to the aggravation caused by the nature and conditions of his employment, it is worth noting that very few activities place more stress on hips than running marathons, and that a recent new study has demonstrated that running does not increase risk of hip osteoarthritis(2) (see below).

In my opinion therefore, a one-fifth deduction would be entirely appropriate in this situation.

(2) American Academy of Orthopaedic Surgeons, 2023 Annual Meeting, March 7 11 in Las Vegas, Nevada."

1. The Medical Assessor took note of the respective assessments Dr Hopcroft and Dr Nair had done of the appellant's permanent impairment from his injury.
2. So, in summary, the Medical Assessor's assessment was that the appellant had 5% WPI of his lumbar spine from his injury, 12% WPI of his left lower extremity from his injury, and 12% WPI of his right lower extremity from his injury, which combined to 27% WPI, and which is what the Medical Assessor certified he assessed is the appellant's degree of permanent impairment from his injury.

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. This is because the material before the Appeal Panel is sufficient for the Appeal Panel to deal with the appeal and correct the errors it found in the MAC. Essentially, the matters raised by the appellant in his appeal can be corrected by reference to the information within the documents before the Appeal Panel.

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 submitted that the Medical Assessor did not properly apply s 323 of the 1998 Act. In substance, the appellant submitted this required the Medical Assessor to determine the degree of his permanent impairment and then to consider whether a pre-existing condition exists and then to determine the extent to which any pre-existing condition, if it exists, contributes to his permanent impairment. The appellant submitted, relying on Cullen v Woodbrae Holdings Pty Ltd[1] (Cullen) at [57] that the pre-existing for which a deduction can be made under s 323(1) had to be a condition that existed before he commenced his employment with the respondent. The appellant submitted that the Medical Assessor did not make any factual finding that he had osteoarthritis prior to the date on which he commenced his employment with the respondent.
3. The appellant noted that he had instituted earlier proceedings in the Commission which were resolved by the making of consent orders, that required the respondent to make weekly payments of compensation to him. The appellant submitted that an issue estoppel arose from those orders that he had suffered an injury to his lumbar spine and hips due to "microtrauma to lumbar spine and hips". The appellant submitted that the Medical Assessor did not give effect to the issue estoppel arising from those orders and made findings that were not open to him to make. The Appeal Panel notes that the appellant did not however detail what the findings were that he contended the Medical Assessor could not make, other than the Medical Assessor drawing an inference that the appellant's treating specialist was of the opinion that his hips problems were not work related.
4. The appellant submitted that the Medical Assessor, in any event, was wrong to infer that his treating specialist was of the opinion that his hip problems where unrelated to work (due to his having had surgery at a public hospital) because that could be explained by other matters, such as his ignorance regarding his right to workers compensation.
5. The appellant submitted that the Medical Assessor, by relying on extraneous material, namely the American Academy of Orthopaedic Surgeons, 2023 annual meeting, March 7-11, acted in a procedurally unfair way because the Medical Assessor did not put that material to him to enable him to respond to it.
6. The appellant submitted that the Medical Assessor failed to consider a report of Dr Hopcroft dated 5 November 2024, in which, the Appeal Panel notes, Dr Hopcroft expressed his view that an additional 2% WPI should be added for the effect of appellant's lumbar spinal injury on his activities of daily living and that no deduction should be made when assessing the appellant's permanent impairment relating to his hips "for pre-existing compromised function prior 16 July 2015". That latter matter was a revision by Dr Hopcroft of his opinion expressed in his report of 14 May 2024 where he advised a deduction of 1/10th should be made when assessing the degree of the appellant's permanent impairment relating to his hips.
7. The appellant noted Dr Hopcroft and Dr Nair expressed different opinions than the Medical Assessor regarding what deduction should be made under s 323 for the proportion of his permanent impairment relating to his hips that was due to a pre-existing condition. The appellant submitted that the Medical Assessor was "required to provided clear reasons why he disagreed with their assessments".
8. The appellant submitted that the Medical Assessor did not abide the instructions in paragraphs 4.33 to 4.36 of the Guidelines when assessing what additional WPI should be added for the effects of his injury on his activities of daily living. The appellant submitted that his capacity to undertake home care tasks and personal tasks have been affected and the Medical Assessor did not address that and that was an error and also a failure of the Medical Assessor to apply the correct criteria. The appellant submitted that the Medical Assessor failed "to grapple with or provide any reasons for disagreeing with the assessments of Dr Hopcroft".
9. The appellant submitted that the Medical Assessor ought to have added 3% WPI that for the effects of his lumbar spine injury on his activities of daily living.
10. In reply, the respondent submitted that the Medical Assessor correctly applied s 323(1) of the 1998 Act. The respondent submitted that the Medical Assessor found that the appellant had extensive degenerative change in his lumbar spine and had constitutional osteoarthritis in his hips.
11. The respondent submitted that the Medical Assessor made the same deduction as Dr Hopcroft had regarding the assessment of the appellant's impairment of the lumbar spine. The respondent submitted Dr Hopcroft made a 1/10th deduction relating to the appellant's hips. The respondent submitted that "it would stand to reason that the deductions applied by [the Medical Assessor] were open on the evidence, and it is not far removed from the assessment of the appellant's IME of Dr Hopcroft and Dr Nair (the respondent's IME) who also made deductions for the assessable body parts".
12. The respondent submitted that on a fair reading of the MAC, the Medical Assessor's observations relating to whether the appellant's need for surgery was the result of his injuries to his hips did not affect his reasoning and where not "fatal to the MAC assessment findings as a whole".
13. The respondent submitted that the extraneous material to which the Medical Assessor referred was not relied on by the Medical Assessor and did not materially impact or change the assessment.
14. The respondent submitted the Medical Assessor was not bound by the assessments of Dr Hopcroft and Dr Nair, nor did he need to be guided by their opinions. The respondent submitted that the Medical Assessor was required to conduct his own independent clinical review of the evidence and based on that and his findings from examination was entitled to make an assessment of the appellant's impairment.
15. The respondent submitted that the Medical Assessor did engage with the reports of Dr Hopcroft and Dr Nair and provided brief comments relating to them.
16. The respondent submitted that the Medical Assessor provided adequate reasons for assessing the appellant has 1% WPI for the effects of his injury on his activities of daily living. The respondent submitted that an addition of a percentage WPI for the effects of an injury on activities of daily living is not based solely on self-reporting. The respondent highlighted that Dr Nair considered that the appellant's limitations with respect to activities of daily living where due to his hip pathology rather than his lumbar spine condition. The respondent further noted that Dr Hopcroft in his initial reports of 24 April 2024 and

14 May 2024 did not assess any impairment relating to the effects of the appellant's injury on his activities of daily living but did so on his report of 5 November 2024.

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.
3. The appellant's injury was a consequence of the work he did for the respondent as a plumber, gas fitter and roofer over the course of approximately five to six years. He commenced his employment with the respondent when he was 47 years old.
4. In such circumstance, the pre-existing condition for which a deduction can be made under

s 323(1) of the 1998 Act, must be a condition that the appellant had at the start of his employment with the respondent.[2] 5. The Appeal Panel notes that the appellant in his statement of 18 August 2022 reveals that he worked in the capacity of plumber between 1985 and July 2015, but the evidence does not reveal the exact nature of the work that he did as a plumber, such that the relevant date at which to consider whether he had a pre-existing for the purpose of determining whether a deduction should be made under s 323(1) of the 1998 Act should be a date earlier than the date upon which he commenced employment with the respondent. The only evidence relating to exactly what he did in his prior employments as a plumber is that he used a jackhammer on 2 May 2015. So, it is not known from the evidence the extent to which he was required in his earlier employment to carry heavy equipment or materials, or to work in confined spaces, or to climb up and down ladders, or to spread blue metal with his feet, or to push heavy concrete pipes or to dig deep trenches, such that the Medical Assessor, or the Appeal Panel in the Medical Assessor's place on review, could infer that the work he did before commencing his employment with the respondent would result in the appellant contracting a disease by gradual process or result in aggravation, acceleration, exacerbation or deterioration of an existing disease in his lumbar spine and hips. In other words, the evidence is not sufficient to reveal whether the terms of ss 15 or 16 catch the appellant's earlier employers. 6. The Appeal Panel is an expert panel that includes two medical specialists within its three members. Relying on that expertise, the Appeal Panel notes that invariably all persons at

47 years of age will have degenerative disease to some extent in their lumbar sacral spine. That is not an assumption. It is a medical fact. 7. The MRI scan that was done of the appellant's lumbar sacral spine on 27 October 2020, which was the only investigation done after he experienced symptoms on 27 August 2020, revealed that the appellant had degenerative disc disease at the L4/5 and the L5/S1 level with circumferential disc bulging and bilateral facet joint hypertrophy causing mild to moderate bilateral L4/5 and moderate to mark bilateral L5/S1 intervertebral foraminal stenosis. The Medical Assessor noted that within the MAC. The Medical Assessor, who is a specialist orthopaedic surgeon, was aware of that finding and the Appeal Panel considers that based on his expertise he considered that some of that degeneration would have existed in the appellant's lumbar spine as of the time the appellant commenced employment with the respondent at the age of 47 years. 8. The Appeal Panel finds that the Medical Assessor did not err in finding that the appellant had a pre-existing condition in his spine prior to his suffering injury. The Appeal Panel is of the same view. Given the appellant's age at the time he commenced employment with the respondent, the degenerative disease revealed by the MRI scan of the appellant's lumbar spine that was done approximately five years after the appellant commenced employment with the respondent, would have to some extent existed before he commenced his employment with the respondent. 9. The Appeal Panel also considers that the Medical Assessor was correct to conclude that a proportion of the appellant's permanent impairment relating to his lumbar spine is due to that pre-existing condition. The appellant's impairment relating to his lumbar spine has been assessed on the basis that the appellant has asymmetric range of movement of his lumbar spine in the plane of his lateral flexion. Because the Medical Assessor found the appellant had that asymmetric movement, the Medical Assessor has correctly correlated the appellant's signs with DRE lumbar category II within Table 15-3 of AMA 5. The appellant's degeneration in his lumbar spine that existed at the time that he commenced employment, and which was aggravated and worsened due to his employment with the respondent, contributes to that asymmetric movement. And hence a proportion of the appellant's permanent impairment is due to that pre-existing condition. 10. Consequently, the Medical Assessor was correct to engage s 323(1) of the 1998 Act when assessing the degree of the appellant's permanent impairment relating to his lumbar spine. It is however difficult to determine with any degree of certainty to what extent the appellant's pre-existing condition would now contribute to his impairment of his lumbar spine. The appellant was not experiencing symptoms before he commenced his employment with the respondent, even though the degeneration in his lumbar spine had by that stage already commenced. In that circumstance, the Appeal Panel considers the Medical Assessor was correct to assume in accordance with s 323(2) of the 1998 Act that the deductible proportion for s 323(1) of the 1998 Act is 10%. 11. With respect to the effect the appellant's lumbar spine injury has on his activities of daily living, the Appeal Panel notes that paragraph 4.33 of the Guidelines provides a Medical Assessor with a discretion to add 1% WPI, 2% WPI, 3% WPI when assessing the degree of a workers' permanent impairment from an injury to the lumbar spine. The instruction in paragraph 4.33 includes that any additional WPI a Medical Assessor decides to add is not to depend solely on self-reporting but must be based on clinical findings and other reports. Within paragraph 4.34 of the Guidelines there is a diagram consisting of three concentric circles that has self-care 3% in the inner most circle, home care 2% in the middle circle and yard/garden/sports/recreation 1% in the outer circle. Paragraph 4.35 provides instructions for how the diagram is to be determined specifying that the base impairment of a worker that is assessed by reference to Table 15-3 of AMA 5 can be increased by 3% WPI if the workers' capacity to undertake personal care activities such as dressing, washing, toileting and shaving has been affected; by 2% WPI if the worker can manage personal care but has restrictions with normal household tasks such as shopping climbing stairs and walking reasonable distances; and by 1% WPI if the worker can cope with personal activities and household activities but is unable to get back to sporting or recreational activities. 12. Bearing in mind that paragraph 4.33 provides a Medical Assessor with a discretion to increase, and not a mandate to increase, and bearing in mind too that any increase a Medical Assessor makes is not based solely on a worker's self-report but must be based on clinical findings and other evidence, the instructions in paragraph 4.35 as to how the diagram of paragraph 4.34 is to be interpreted does not, it seems to the Appeal Panel, require a Medical Assessor to increase the base impairment allowed by Table 15-3 by 3% WPI if a worker experiences limited difficulty with personal care activities. Nor does it require a Medical Assessor to increase the base impairment by 2% WPI is the worker has limited difficulty with household tasks. The task of a Medical Assessor in applying paragraph 4.33 requires the Medical Assessor to balance all relevant matters relating to the impact that a worker's injury has on the worker's activities of daily living to determine whether and to what extent the base impairment ought to be increased. 13. The history the Medical Assessor obtained included that the appellant walks three to four kilometres, can drive a couple of hours, can assist with housework although with difficulty in some aspects of housework such as making a bed, can carry a carton of beer and can mow the lawns on his property, although not dig holes. The Medical Assessor also noted that the appellant has difficulty with his shoes and socks but continues to do them. In the Appeal Panel's view the Medical Assessor's clinical judgement that the appellant has 1% WPI due to the effect of his lumbar spine injury on his activities of daily living, is sound. Whilst other clinicians have expressed different opinions regarding this, such that his impairment is 2% WPI, a difference of opinion does not amount to a demonstrable error. 14. The Appeal Panel considers that the Medical Assessor provided adequate reasons for his assessment that the effect of the appellant's injury of his lumbar spine on his activities of daily living is 1% WPI. The Medical Assessor has made no error with respect to that. Further, the Medical Assessor has applied the correct criteria to assess that element of the medical dispute. 15. With respect to the Medical Assessor's assessment of the degree of the appellant's permanent impairment regarding the injury to his hips, the Appeal Panel considers the Medical Assessor has erred by finding that the appellant had a condition in his hip at the time he commenced employment with the respondent. In contrast to the situation regarding the condition of the lumbar spine of a 47 year old person, it is not commonplace for a person of such age to have osteoarthritis in the hips. 16. The evidence here is that the appellant did not experience symptoms in his hips prior to commencing his employment with the respondent. He did experience some symptoms after he commenced employment, but until the incident in August 2020 they were not of a serious nature. A MRI of his left hip done on 21 November 2020 revealed extensive degenerative labral tearing and grade III - IV chondromalacia and moderate osteoarthropathy. A similar finding was made on X-ray done shortly thereafter on 1 December 2020. An X-ray done of his pelvis and left hip on 4 June 2021 revealed marked osteoarthritis in his hip joints on both sides. 17. Absent the appellant suffering significant symptoms in his hips prior to commencement of his employment with the respondent and absent an investigation done at or about the time the appellant started employment with the respondent, the Appeal Panel considers that the Medical Assessor was wrong to conclude what the Medical Assessor described as "constitutional idiopathic osteoarthritis" existed at the time the appellant commenced his employment with the respondent. It is the case that some people have a genetic predisposition to develop osteoarthritis and that can happen idiopathically. Here, noting the nature of the work the appellant did for the respondent and the fact he did not experience symptoms before he commenced employment for the respondent, the Appeal Panel considers that there was no proper basis for the Medical Assessor to form the view that any predisposition of the appellant to develop osteoarthritis had manifested prior to his employment with the respondent. That is to say, there is not evidence that the degenerative process of arthritis had commenced in his hips prior to the appellant's commencing his employment with the respondent. 18. Consequently, the Medical Assessor erred by making a deduction under s 323(1) of the 1998 Act for a proportion of the appellant's impairment of his hips being due to a pre-existing condition, because the evidence does not indicate that the appellant had a pre-existing condition in his hips at the relevant time. 19. The Appeal Panel must correct that error, and does so by not making a deduction under

s 323(1) of the 1998 Act, with the result being that the assessment of the degree of the appellant's permanent impairment with respect to each of his left lower extremity and right extremity is 15% WPI. 20. That strictly makes it unnecessary to consider the other submission of the appellant, being that the Medical Assessor did not have regard to Dr Hopcroft's opinion expressed in his report of 5 November 2024, that he did not explain why his assessment differed from the assessments Dr Hopcroft and Dr Nair, that he did not afford the appellant procedural fairness, and that he did not abide an issue estoppel arising from the consent orders made on 23 January 2023. 21. Notwithstanding that there is now no need for the Appeal Panel to deal with these matters, the Appeal Panel shall do so but only briefly. 22. The Medical Assessor by referring to material that was not part of the brief documents provided to him for the purpose of the assessment, and by not giving the parties the opportunity to address that material denied the parties procedural fairness. It would seem from the MAC that the material played a part in the Medical Assessor's reasoning that a proportion of the appellant's permanent impairment was due to a pre-existing condition in the appellant's hips. In that circumstance both parties ought to have been provided the opportunity to address the Medical Assessor on it. 23. It would seem that the Medical Assessor did not have regard to the report of Dr Hopcroft dated 5 November 2024. Dr Hopcroft had revised his assessment that he expressed in his earlier report. The Medical Assessor only referred to the assessment that Dr Hopcroft had advised in his earlier report. 24. The obligation of a Medical Assessor under s 325(2) of the 1998 Act does not require the Medical Assessor to refer in the MAC to every piece of evidence. The Medical Assessor must however consider all relevant evidence and it is an error for a Medical Assessor not to do so.[3] 25. It can be inferred from the fact that the Medical Assessor referred to the assessment Dr Hopcroft expressed in his earlier report, rather than his later report, that the Medical Assessor neglected to consider the report of Dr Hopcroft. 26. The Appeal Panel considers that the report of Dr Hopcroft dated 5 November 2024 was relevant evidence and the Medical Assessor erred by not considering it. 27. The obligation of a Medical Assessor under s 325(2)(c) of the 1998 Act to explain his or her reasons for the assessment of the degree of a worker's permanent impairment requires the Medical Assessor to expose the path of his or her reasoning for the assessment made. That obligation however does not require the Medical Assessor to explain why he or she did not assess the worker's impairment the same as another clinician.[4] The Medical Assessor was not required therefore to explain why his assessment differed from the assessment of Dr Hopcroft and Dr Nair made. 28. The Appeal Panel does not accept the appellant's submission to the effect that the Medical Assessor did not apply an issue estoppel arising from the consent orders. Essentially, the issue estoppel was that the appellant suffered an injury with the description of s 4(b) of the 1987 Act. It is apparent from the MAC that the Medical Assessor was aware of that and assessed the degree of the appellant's permanent impairment from such an injury. 29. The Appeal Panel agrees with the appellant that the Medical Assessor erred by drawing an inference from the fact that the appellant's left hip replacement surgery was done at a public hospital that the appellant's treating surgeon considered the appellant's osteoarthritis was unrelated to his work. That fact simply provides no reasonable basis for such an inference can be drawn. 30. For these reasons, the Appeal Panel has determined that the MAC issued on

14 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 Roger Pillemer 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 AMA 5 Guides

Proportion of permanent impairment due to pre-existing injury, abnormality or condition

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

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

[2] Cullen v Woodbrae Holdings Pty Ltd [2015] NSWSC 1416 (Cullen) at [47]- [58]; Craigie v Faircloth & Reynolds Pty Ltd [2021] NSWSC 1211; Oswell v Sublime Install Pty Ltd [2024] NSWSC 1586 at [85]- [92].

[3] Tattersall v Registrar of the Workers Compensation Commission of NSW & Anor [2007] NSWSC 453 at [14] [18]; Wentworth Community Housing Ltd v Brennan [2019] NSWSC 152 at [70]- [76].

[4] Wingfoot Aust Partners Pty Ltd v Kocak [2013] HCA43 at [47] and [56]