Belavic v State of New South Wales (Hunter New England Local Health District)

DETERMINATION OF APPEAL PANEL
CITATION:	Belavic v State of New South Wales (Hunter New England Local Health District) [2025] NSWPICMP 136
APPELLANT:	Suzanna Belavic
RESPONDENT:	State of New South Wales (Hunter New England Local Health District)
APPEAL PANEL
MEMBER:	Rachel Homan
MEDICAL ASSESSOR:	Christopher Oates
MEDICAL ASSESSOR:	Roger Pillemer
DATE OF DECISION:	3 March 2025
CATCHWORDS:	WORKERS COMPENSATION - Workplace Injury Management and Workers Compensation Act 1998; whether demonstrable error or incorrect application of criteria in Medical Assessor’s finding that 50% of whole person impairment (WPI) to be “apportioned” to a subsequent aggravation; whether Medical Assessor erred in making a deduction pursuant to section 323 where there was asymptomatic pre-existing early osteoarthritic change; Held – Appeal Panel agreed; Medical Assessment Certificate revoked.

BACKGROUND TO THE APPLICATION TO APPEAL

On 19 December 2024, Suzanna Belavic (the appellant) lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr David Lewington, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on
26 November 2024.
The appellant relies on the following grounds of 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.
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.
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.
The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4^th ed
1 March 2021 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5^th ed (AMA 5).

RELEVANT FACTUAL BACKGROUND

On 25 December 2020, the appellant, who is a nurse, was assisting a colleague to get a patient out of bed when she crouched into a squat in an awkward position. When the appellant stood upright, she felt intense pain in her left knee. The appellant made a claim for compensation, which was accepted.
The injury was managed by the appellant’s general practitioner. The appellant was referred for physiotherapy and radiological investigations.
In April 2021, the appellant was referred to an orthopaedic surgeon, Dr David Dewar, who recommended conservative management and weight loss. It was noted that if symptoms did not settle, the appellant would likely need left knee replacement.
In May 2021, the appellant slipped on a floor that had just been mopped and fell onto her left knee. This aggravated the appellant’s symptoms. A short time later, the appellant returned to the room and slipped again but did not fall on the still wet floor. The appellant experienced more pain.
The appellant returned to Dr Dewar for review in January 2022 and a left total knee replacement surgery was requested. The surgical procedure was performed on
23 May 2022.
The appellant made a claim for lump sum compensation based on an assessment of 20% whole person impairment (WPI) resulting from the injury on 25 December 2020 made by
Dr Murray Hyde Page on 14 December 2023.
The claim for lump sum compensation was disputed in a notice issued under s 78 of the 1998 Act on 25 July 2024. The respondent’s insurer relied on an assessment made by A/Prof Paul Miniter in which he found 0% WPI resulting from injury on the basis that there was no identifiable work-related component to the impairment at the applicant’s left knee.
Proceedings were commenced in the Personal Injury Commission (Commission). The Application to Resolve a Dispute identified a single “personal injury” on 25 December 2020. In the absence of a liability dispute, the medical dispute was referred to the Medical Assessor.
The referral identified the dispute as the degree of permanent impairment resulting from the injury on 25 December 2020 to the appellant’s left lower extremity (knee).
In the MAC issued on 26 November 2024, the Medical Assessor recorded a history that was broadly consistent with the materials before him. The Medical Assessor noted the aggravations to the left knee in May 2021.
The Medical Assessor assessed 20% WPI following the left total knee replacement, of which he “apportioned” 50% to the injury on 25 December 2020, with the remainder to an injury in May 2021. From the 10% WPI remaining for the injury on 25 December 2020, a 1/10 deduction was made for pre-existing condition, leaving a final total of 9% WPI.

PRELIMINARY REVIEW

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.
As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination because there was sufficient material available to the Appeal Panel on which to resolve the appeal.

EVIDENCE

Documentary evidence

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.

Medical Assessment Certificate

The parts of the medical certificate given by the Medical Assessor that are relevant to the appeal are set out, where relevant, in the body of this decision.
After recording a history of the injury on 20 December 2020, the Medical Assessor noted that the appellant was treated with physiotherapy under the care of her general practitioner. It was noted that the appellant had never been able to return to her normal duties because of the physically demanding nature of that job. The appellant continued to work full-time in a variety of light clinical roles.
The Medical Assessor noted that X-rays performed in April 2021 revealed mild to moderate osteoarthritis. Dr Dewar had diagnosed mild to moderate osteoarthritis with small osteophytes and a small cyst, particularly in the retro patella space. It was noted that there were no past symptoms at the left knee, although there was an underlying knee osteoarthritis.
The Medical Assessor referred to the aggravations of the left knee in May 2021. The appellant had described this as a significant injury in terms of aggravating her pain and overall due deterioration of her condition. The appellant reduced her light clinical work from full-time to four days per week following the incidents in May 2021.
The Medical Assessor noted that Dr Dewar did not refer to the May 2021 incidents in his reports of 12 October 2021 or 14 February 2022. The report of 14 February 2022 referred to a medial meniscal tear and deterioration leading to the need for the total knee replacement. There had been no mention of a meniscal tear in Dr Dewar’s previous correspondence on
27 April 2021.
An MRI scan performed on 25 February 2021 had identified that the medial and lateral menisci were intact.
An MRI performed on 24 January 2022 showed a subchondral insufficiency fracture of the medial condyle as well as complex medial meniscal tear with extrusion and knee joint effusion.
An X-ray performed on 4 May 2022 showed flattening of the condyle of the left knee, suggesting underlying osteochondral defect. An MRI scan in May 2022, showed advanced osteoarthritis in the left knee.
The Medial Assessor stated:
“It is clear that the subject injury 25 December 2020 was a significant injury clinically causing ongoing pain and permanent change in work duties, and with imaging investigations consistent with mild-to-moderate osteoarthritis rendered symptomatic by that injury.
There is also clear imaging evidence that subsequent injuries in May 2021 were associated with significant clinical deterioration and with the imaging reports for the first time of medial meniscal tear in the left knee and bony injury to the left femoral condyle; variously reported a subchondral insufficiency fracture, flattening of the condyle or osteochondral defect.
I assess a 50% apportionment to the injury 25 December 2020 and the subsequent injury in May 2021.The left total knee replacement is assessed 20% W.P.I in total and with 10% W.P.I for injury December 2020 and 10% W.P.I May 2021. There is a 1/10 deduction for pre-existing condition.”
With regard to the deduction for pre-existing condition, the Medical Assessor noted that
Dr Hyde Page had found no deductible proportion. Associate Professor Miniter made a 100% deduction. The Medical Assessor found A/Prof Miniter’s deduction excessive and at odds with the available evidence.
The Medical Assessor stated:
“Imaging investigations taken relatively soon after the subject injury 25 December 2020 are consistent with some degree of pre-existing osteoarthritis (predating the subject injury on 25 December 2020) and ultimately contributing to the need for knee replacement but it is difficult to determine the extent of its contribution and under Section 323 is properly assigned a 1/10th deductible proportion.”

SUBMISSIONS

Both parties made written submissions. They are not repeated in full but have been considered by the Appeal Panel.
The appellant submitted that the assessment was made on the basis of incorrect criteria, and that the MAC contained a demonstrable error, because the Medical Assessor:
(a) improperly found and assessed WPI attributable to a second injury, and
(b) incorrectly applied s 323 of the 1998 Act.
The appellant noted that there was an accepted injury to the left knee on 25 December 2020. The respondent’s dispute notice and the report from A/Prof Miniter raised no issue with respect to contribution to impairment from an injury in May 2021. Neither the appellant’s statement nor the report from Dr Hyde Page indicated any contribution to WPI from an injury in May 2021.
The appellant submitted that the Medical Assessor failed to properly consider and acknowledge the history of deteriorating symptomology from the time of the accepted injury and the absence of reference to differing symptomology or incapacity following the May 2021 incident. The treating and medicolegal opinions before the Medical Assessor identified a continuing, deteriorating clinical picture following the subject injury leading to the ultimate need for the knee replacement surgery.
The appellant submitted that the Medical Assessor erred in determining that a second injury was able to be assessed and in forming the view that the incident in May 2021 resulted in separate and distinct pathology to the knee. The appellant referred to the decisions in Ozcan v Macarthur Disability Services Ltd [2021] NSWCA 56 and Skates v Hills Industries Limited [2021] NSWCA 142 in support of her submission that the Medical Assessor impermissibly made a determination on ‘injury’.
In the alternative, the appellant submitted that in proposing a new theory or opinion on causation of permanent impairment, the Medical Assessor had denied the appellant natural justice and the opportunity of obtaining evidence to address the new theory.
The appellant also submitted that the Medical Assessor erred in making a 1/10 deduction under s 323 of the 1998 Act. The Medical Assessor had explicitly accepted that the applicant’s osteoarthritic condition had been asymptomatic prior to the injury on
25 December 2020. The appellant said that Cole v Wenaline Pty Ltd (2010) NSWSC 78 was authority for the proposition that in order for a deduction to be made under s 323 there must be evidence of a pre-existing abnormality, condition or previous injury that contributes to the impairment.
The appellant submitted that the mere existence of ‘degenerative change’ is insufficient to warrant a deduction. In this case, there was no pre-existing condition for which an attributable impairment could be identified.
In opposing the appeal, the respondent submitted that the appellant’s submissions simply cavilled with a difference in clinical opinion. The submissions did not demonstrate a readily apparent error or that the Medical Assessor’s reasoning was unsupported or glaringly improbable.
The respondent submitted that the Medical Assessor relied on evidence served with the Application to Resolve a Dispute and recorded during the clinical examination. The Medical Assessor proceeded to assess impairment resulting from the injury on 25 December 2020 as he was required to do. The deduction made under s 323 of the 1998 Act was supported by the available evidence and not in error.
The respondent noted that the appellant acknowledged the incidents in May 2021 and they were consistently referred to in the evidence from Dr Dewar, Dr Hyde Page and A/Prof Miniter. The respondent said it was not apparent how the appellant had been denied any opportunity to address the incidents.
The respondent submitted that the Medical Assessor was obliged to form his own opinion. The Medical Assessor was obliged to assess impairment arising from the injury on
25 December 2020. The Medical Assessor identified an aggravation in May 2021. The Medical Assessor made no assessment of an injury in May 2021. It was open to the Medical Assessor to attribute a percentage of impairment to the second injury in providing an assessment of the impairment resulting from the subject injury listed in the referral.
The respondent submitted that the appellant had not identified how the Medical Assessor misapplied relevant guidelines.
With regard to the s 323 deduction, the respondent referred to the decisions in Elcheikh v Diamond Formwork (NSW) Pty Limited (in liquidation) (2013) NSW 365; Cole v Wenaline Pty Ltd [2010] NSWSC 78 and the Guidelines, noting that the fact that the pre-existing condition had been asymptomatic did not preclude it from contributing to the impairment being assessed. The respondent submitted that the correct approach was that set out by Campbell J in Ryder v Sundance Bakehouse [2015] NSWSC 526.
The respondent referred to the evidence of pre-existing pathology. It was also noted that A/Prof Miniter considered that the appellant’s age, sex and bone quality were relevant. The appellant’s pathology was said to be common in women of the appellant’s age and weight. The appellant’s weight of 130kg at the time of A/Prof Miniter’s initial interview was identified as a significant factor in the development of the osteoarthritis.
The respondent submitted that there was ample evidence before the Medical Assessor, which he considered and referred to, demonstrating that there was a substantial pre-existing pathology that contributed to the appellant’s impairment. The Medical Assessor referred to the evidence and explained his reasons for assessment. There was no error in the Medical Assessor’s methodology or application of the relevant criteria.

FINDINGS AND REASONS

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
In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
In Tasevski v Westpac Banking Corporation [2024] NSWSC 41, Schmidt AJ, referring to the High Court decision in Vannini v Worldwide Demolitions Pty Ltd [2018] NSWCA 324, commented on the meaning of the term, “demonstrable error”:
“Gleeson JA explained that ‘demonstrable error’, a term which is not defined, is intended to convey the degree of strictness of scrutiny to which the disputed assessment may be subjected. As such, a finding of ‘error alone is not sufficient’. The error must be ‘material’ and apparent in the certificate, although there is no limit on the material to which the Panel may have regard when assessing whether the certificate ‘contains’ a demonstrable error: at [77]-[78].
An error is also not demonstrable merely because the Panel disagrees with the assessor’s opinion: at [87]. An error for which there is no information or material to support the finding made, rather than a difference of opinion, will establish a demonstrable error.”
The Appeal Panel has reviewed the history recorded by the Medical Assessor, his findings on examination, the evidence before him and the reasons for his conclusions in light of the submissions made by the parties.

Apportionment of impairment to the May 2021 incidents

The Appeal Panel is satisfied that there was a demonstrable error in the Medical Assessor’s approach to the incidents in May 2021.
In Skates v Hills Industries Ltd [2021] NSWCA 142, the Court of Appeal confirmed that a Medical Assessor is confined by the “medical dispute” referred for assessment. The majority held that the scope of the medical dispute could be ascertained from the parties’ competing claims as set out in their medical reports and the dispute raised by the insurer.
It is also well established that the statutory scheme for settlement of workers compensation disputes provides for factual and liability disputes to be resolved by Members of the Commission with certain medical disputes to be resolved by a Medical Assessor subject to appeal to a Panel.[1]
[1] See, for example, Haroun v Rail Corporation New South Wales [2008] NSWCA and Jaffarie v Quality Castings Pty Ltd [2018] NSWCA 88.
In the present case, the medical dispute referred to the Medical Assessor required him to assess the degree of permanent impairment resulting from the injury on 25 December 2020. While the materials relied on by both the appellant and the respondent made reference to the incidents in May 2021, nothing in the referral or the documents exchanged between the parties indicates that liability for an “injury” in May 2021 had been accepted or that there was a dispute as to the degree of permanent impairment resulting from those incidents.
It was not open to the Medical Assessor to determine for himself that there was an “injury” in May 2021. Nor was there any legal basis for the Medical Assessor to “apportion” or reduce the total WPI on the basis of subsequent injury. There is no provision in the statutory scheme that allows for a reduction in WPI on the basis of subsequent injuries in the way that s 323 of the 1998 Act provides for a deduction for a previous or pre-existing injury, abnormality or condition.
That is not to say that the May 2021 incidents were irrelevant to the Medical Assessor’s task. In State Government Insurance Commission v Oakley (1990) 10 MVR 570; [1990] Aust Torts Reports 81-003, Malcolm CJ identified three categories of case where a subsequent injury is relevant to the assessment of damages consequential upon an earlier injury. While the Chief Justice’s observations were made in the context of proceedings at common law, they have been found to be equally applicable to the assessment of the degree of permanent impairment resulting from injury under the statutory workers compensation scheme.[2] In particular, they are consistent with the requirement in s 65(1) of the 1987 Act to consider the degree of permanent impairment which “results from” the injury in question. The three categories were described as:
“(1) where the further injury results from a subsequent accident, which would not have occurred had the plaintiff not been in the physical condition caused by the defendant’s negligence, the added damage should be treated as caused by that negligence;
(2) where the further injury results from a subsequent accident, which would have occurred had the plaintiff been in normal health, but the damage sustained is greater because of aggravation of the earlier injury, the additional damage resulting from the aggravated injury should be treated as caused by the defendant's negligence; and
(3) where the further injury results from a subsequent accident which would have occurred had the plaintiff been in normal health and the damage sustained include [sic] no element of aggravation of the earlier injury, the subsequent and further injury should be regarded as causally independent of the first.”
[2] See Secretary, New South Wales Department of Education v Johnson (2019) NSWCA 321.

The Appeal Panel finds that the present case falls within the second category.
The material before the Appeal Panel does not indicate that the slips and fall in May 2021 resulted from the injury on 25 December 2020. Rather the evidence suggests that the incidents occurred due to the floor on which the appellant was walking remaining slippery and wet after having been mopped by a cleaner.
Nor does the Appeal Panel accept that the incidents in May 2021 resulted in separate pathology or contained no element aggravation of the earlier injury.
In this regard, the Appeal Panel notes that the Medical Assessor appears to have overlooked significant evidence. As noted above, the Medical Assessor placed considerable weight on the radiological evidence of a meniscal tear found on MRI performed on 24 January 2022 which had not previously been identified in the scan performed on 25 February 2021. The Medical Assessor also noted that Dr Dewar did not refer to the May 2021 incidents in his reports of 12 October 2021 or 14 February 2022. The report of 14 February 2022 referred to a medial meniscal tear and deterioration while there had been no mention of a meniscal tear in Dr Dewar’s previous correspondence on 27 April 2021.
The Medical Assessor does not appear to have turned his attention to the report from
Dr Dewar dated 30 July 2021 in which he did refer to the further fall in May 2021. Dr Dewar said he had arranged for X-rays which revealed “no change from before”. The X-rays were still demonstrating early osteoarthritis.
Consistently with Dr Dewar’s observations, A/Prof Miniter commented on the July 2021 X-rays in his report of 13 January 2022 and said there was no clear evidence of recent trauma and the patellofemoral changes were the same as they were in the April 2021 investigation.
While it is true that the radiological evidence indicates a deterioration in the pathology at the appellant’s left knee by early 2022, the X-ray investigations shortly after the May 2021 fall did not demonstrate any acute pathological change.
The Appeal Panel considers that the deterioration in pathology seen in early 2022 is consistent with the natural progression of the condition at the appellant’s left knee following the 25 December 2020 injury.
The appellant had been seen by Dr Dewar shortly before the May 2021 incidents, in
April 2021, as her knee “had not improved” since the injury on 25 December 2020. The Appeal Panel notes that a total knee replacement was contemplated at the time Dr Dewar first saw the appellant if her symptoms did not settle.
In her statement evidence, the history given to the Medical Assessor and in the histories given to the medicolegal experts, the appellant has described the incidents in May 2021 as aggravating or worsening the pain and stiffness which had commenced with and had persisted since the injury on 25 December 2020. All of the evidence suggests that the appellant’s symptoms continued to progressively worsen in the lead up to the total knee replacement.
Having considered the evidence and submissions, the Appeal Panel is satisfied that in “apportioning” WPI to a May 2021 injury, the Medical Assessor exceeded his jurisdiction and the MAC was affected by demonstrable error.
The Appeal Panel finds that there was no basis for reducing or apportioning impairment due to the May 2021 incidents. The Appeal Panel is satisfied that all of the WPI found by the Medical Assessor “resulted from” the 25 December 2020 injury, subject to the application of s 323 of the 1998 Act.

Deduction for previous injury or pre-existing condition or abnormality

The appellant submits that the Medical Assessor also erred in making a deduction pursuant to s 323 of the 1998 Act.
Section 323 of the 1998 Act provides:
“323   Deduction for previous injury or pre-existing condition or abnormality
(1)     In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality.
(2)     If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence.
Note –
So if the degree of permanent impairment is assessed as 30% and subsection (2) operates to require a 10% reduction in that impairment to be assumed, the degree of permanent impairment is reduced from 30% to 27% (a reduction of 10%).
(3)     The reference in subsection (2) to medical evidence is a reference to medical evidence accepted or preferred by the approved medical specialist in connection with the medical assessment of the matter.
(4)     The WorkCover Guidelines may make provision for or with respect to the determination of the deduction required by this section.”
The approach to be taken in assessing the s 323 deduction was considered by the Supreme Court in Cole v Wenaline Pty Ltd [2010] NSWSC 78 where Schmidt J said:
“The section is directed to a situation where there is a pre-existing injury, pre-existing condition or abnormality. For a deduction to be made from what has been assessed to have been the level of impairment which resulted from the later injury in question, a conclusion is required, on the evidence, that the pre-existing injury, pre-existing condition or abnormality caused or contributed to that impairment.
Section 323 does not permit that assessment to be made on the basis of an assumption or hypothesis, that once a particular injury has occurred, it will always, ‘irrespective of outcome’, contribute to the impairment flowing from any subsequent injury. The assessment must have regard to the evidence as to the actual consequences of the earlier injury, pre-existing condition or abnormality. The extent that the later impairment was due to the earlier injury, pre-existing condition or abnormality must be determined. The only exception is that provided for in s 323(2), where the required deduction ‘will be difficult or costly to determine (because, for example, of the absence of medical evidence)’. In that case, an assumption is provided for, namely that the deduction ‘is 10% of the impairment'. Even then, that assumption is displaced, if it is at odds with the available evidence.
... as was discussed in the authorities, an earlier injury which was asymptomatic, may or may not contribute to the impairment which results from a second injury. That is a matter of fact to be assessed on the evidence led in each case.
…What must be determined on the evidence is whether any proportion of the permanent impairment present after the second injury was due to the earlier injury.”
In Elcheikh v Diamond Formwork (NSW) Pty Ltd (in liq) [2013] NSWSC 365, her Honour confirmed:
“As discussed in Cole v Wenaline Pty Limited at [30], in the case of a workplace injury caused by an exacerbation or acceleration of a pre-existing condition, what must be determined by a medical specialist under s 323 is:
•       Firstly, what the extent of the resulting impairment is.
•       Secondly, whether the pre-existing condition contributed to the impairment.
•       Thirdly, if it did, what proportion of the impairment was due to the pre-existing condition.”
In Ryder v Sundance Bakehouse [2015] NSWSC 526, Campbell J observed:
“What s 323 requires is an inquiry into whether there are other causes, (previous injury, or pre-existing abnormality), of an impairment caused by a work injury. A proportion of the impairment would be due to the pre-existing abnormality (even if that proportion cannot be precisely identified without difficulty or expense) only if it can be said that the pre-existing abnormality made a difference to the outcome in terms of degree of impairment resulting from the work injury. If there is no difference in outcome, that is to say, if the degree of impairment is not greater than it would otherwise have been as a result of the injury, it is impossible to say that a proportion of it is due to pre-existing abnormality. To put it another way, the Panel must be satisfied that but for the pre-existing abnormality, the degree of impairment resulting from the work injury would not have been as great.”
The radiological evidence and medical opinions before the Medical Assessor were consistent with his finding that there was early osteoarthritic change at the appellant’s left knee that pre-dated the injury on 25 December 2020.
The Medical Assessor also acknowledged, consistently with the evidence before him, that the early osteoarthritic change was asymptomatic prior to the 25 December 2020 injury.
In finding that a deduction was warranted, the Medical Assessor commented that the pre-existing condition “ultimately contributed to the need for knee replacement”.
The appellant submits that mere existence of degenerative change is insufficient to warrant a deduction. No impairment attributable to the pre-existing condition was identified by the Medical Assessor.
In response, the respondent submitted that the Medical Assessor explained his path of reasoning in sufficient detail. The respondent also referred to A/Prof Miniter’s observations that the appellant’s age, sex and bone quality were also pre-existing conditions that led to an insufficiency fracture and ultimately the total knee replacement.
The Appeal Panel accepts that, depending on the circumstances, a s 323 deduction can be made for an asymptomatic condition.[3] The authorities referred to above make clear, however, that the question is whether on the evidence, the pre-existing condition or abnormality caused or contributed to the impairment.
[3] See, for example, Vitaz v Westform (NSW) Pty Ltd [2011] NSWCA 254 at [43].
While the Medical Assessor asserted that the degenerative change contributed to the need for knee replacement surgery, the Appeal Panel finds that the Medical Assessor has not explained how the pre-existing early osteoarthritic changes contributed to the impairment.
It could not be assumed that simply because there was pre-existing osteoarthritic change it contributed to the impairment flowing from the injury. The Medical Assessor was required to have regard to the evidence as to the actual consequences of the pre-existing condition and assess whether any proportion of the permanent impairment present after the workplace injury was due to that pre-existing condition.
In this regard, the Appeal Panel accepts that the Medical Assessor failed to provide adequate reasons for the deduction and this constituted a demonstrable error.
The pre-existing changes in this case were mild. The MRI on 25 February 2021 showed ‘no significant chondromalacia within the medial or lateral compartments’.
An X-ray on 27 April 2021 showed ‘mild osteoarthritis of the mediolateral, tibiofemoral compartments, and moderate osteoarthritis medial and lateral patellofemoral compartments with joint space loss and spurring’. The X-ray findings were slightly more significant than those noted on the earlier MRI.
There is no evidence that the pre-existing changes were symptomatic or causing any of the restrictions or impairments subsequently found by the Medical Assessor prior to the event on 25 December 2020. The evidence indicates that the injurious event triggered an acute onset of symptoms and a rapid progressive deterioration of the condition due to which the surgery was required.
The Appeal Panel’s view of the evidence is consistent with Dr Hyde Page’s observations:
“She gives no history of any previous injury or complaint affecting her left knee. This is pointed out when she initially saw Dr Dewar. The underlying osteoarthritis in her left knee was not severe and had never been symptomatic. Overall, I consider there is no deduction for any pre-existent injury or condition. The knee only became progressively symptomatic after her work injury.”
The Appeal Panel is satisfied that there was no real contribution to the current level of impairment from the pre-existing degenerative change.
With regard to matters identified by A/Prof Miniter, including the appellant’s age, gender and bone quality, the Appeal Panel notes that in Cullen v Woodbrae Holdings Pty Ltd [2015] NSWSC 1416, Beech-Jones J ay [46] reiterated that s 323 required evidence of an actual pre-existing condition rather than a predisposition or susceptibility.
The Appeal Panel is satisfied that no proportion of the WPI was due to the pre-existing condition.
For these reasons, the Appeal Panel has determined that the MAC issued on
26 November 2024 should be revoked, and a new MAC should be issued. The new certificate is attached to this statement of reasons.

WORKERS COMPENSATION DIVISION

APPEAL PANEL

MEDICAL ASSESSMENT CERTIFICATE

Injuries received after 1 January 2002

Matter number:	W26338/24
Applicant:	Suzanna Belavic
Respondent:	State of New South Wales (Hunter New England Local Health District)

This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act1998.

The Appeal Panel revokes the Medical Assessment Certificate of Medical Assessor David Lewington and issues this new Medical Assessment Certificate as to the matters set out in the Table below:

Table - whole person impairment (WPI)

Body Part or system	Date of Injury	Chapter, page and paragraph number in NSW workers compensation guidelines	Chapter, page, paragraph, figure and table numbers in AMA 5 Guides	% WPI	Proportion of permanent impairment due to pre-existing injury, abnormality or condition	Sub-total/s % WPI (after any deductions in column 6)
1.	Left lower extremity (knee)	Scoring Total Knee Replacements: Chapter 3, Page 21, Paragraph 3.30, Table 17 - 35 (replaces Table 17 - 35 in A.M.A 5).	Chapter 17, Page 547, Table 17 33.	20%	Nil	20%
Total % WPI (the Combined Table values of all sub-totals)					20%

[2025] NSWPICMP 136

3 March 2025