Chapman v Tomago Aluminium Company Pty Ltd

CERTIFICATE OF DETERMINATION OF MEMBER
Citation:	Chapman v Tomago Aluminium Company Pty Ltd [2023] NSWPIC 307
APPLICANT:	Ray Samuel Chapman
RESPONDENT:	Tomago Aluminium Company Pty Limited
Member:	Gaius Whiffin
DATE OF DECISION:	28 June 2023
CATCHWORDS:	WORKERS COMPENSATION - Workers Compensation Act 1987; claim for bilateral knee injuries; claim for compensation pursuant to section 66 based on three accepted injuries as well as a disputed injury pursuant to section 4(b)(ii); consideration of applicant’s statements, medical reports and other treatment records, as well as claim correspondence; consideration of whether the applicant sustained an injury in the form of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with section 4(b)(ii) with a deemed date of 8 August 2022, due to the nature of his employment duties with the respondent; AV v AW, ACW v ACX, Jaffarie v Quality Castings Pty Limited and Bindah v Carter Holt Harvey Wood Products Australia Pty Limited considered; Held – the applicant sustained an injury in the form of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with section 4(b)(ii) with a deemed date of 8 August 2022, due to the nature of his employment duties with the respondent; the determination of the applicant’s whole person impairment as a result of that injury will be remitted to the President for referral to a Medical Assessor (together with the determinations of the applicant’s whole person impairment as a result of his three accepted injuries).
determinations made:	The Commission determines: 1. The applicant sustained an injury in the form of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with s 4(b)(ii) of the Workers Compensation Act 1987 (the 1987 Act) with a deemed date of 8 August 2022, due to the nature of his employment duties with the respondent. The Commission orders: 1. I remit this matter to the President for referral to a Medical Assessor pursuant to s 321 of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act) for assessment as follows: (a) date of injury: 18 August 2007; (b) body systems/parts: left lower extremity (knee), scarring (TEMSKI), and (c) method of assessment: whole person impairment. 2. I remit this matter to the President for referral to a Medical Assessor pursuant to s 321 of the 1998 Act for assessment as follows: (a) date of injury: 11 June 2018; (b) body systems/parts: left lower extremity (knee), scarring (TEMSKI), and (c) method of assessment: whole person impairment. 3. I remit this matter to the President for referral to a Medical Assessor pursuant to s 321 of the 1998 Act for assessment as follows: (a) date of injury: 18 November 2018; (b) body systems/parts: right lower extremity (knee), scarring (TEMSKI), and (c) method of assessment: whole person impairment. 4. I remit this matter to the President for referral to a Medical Assessor pursuant to s 321 of the 1998 Act for assessment as follows: (a) date of injury: 8 August 2022 (deemed); (b) .body systems/parts: left lower extremity (knee), right lower extremity (knee), scarring (TEMSKI), and (c) method of assessment: whole person impairment. 5. The documents to be reviewed by the Medical Assessor are: (a) the Application to Resolve a Dispute, and attached documents; (b) the Reply lodged by the respondent in the interests of GIO, and attached documents; (c) the Reply lodged by the respondent in its interests as self-insurer, and attached documents; (d) the Application to Admit Late Documents lodged by the applicant and dated 20 April 2023, and attached documents; (e) the Application to Admit Late Documents lodged by the respondent in the interests of GIO and dated 25 May 2023, and attached documents; (f) the Application to Admit Late Documents lodged by the respondent in its interests as self-insurer and dated 26 May 2023, and attached documents; and (g) this Certificate of Determination and its attached reasons. 6. The Medical Assessment referral is also to contain a notation that the applicant has already received compensation for 1% whole person impairment in relation to the 18 August 2007 injury by way of a complying agreement dated 27 May 2009. 7. Following the completion of the Medical Assessment process, the matter is to be re-listed before me for a preliminary conference to deal with any unresolved disputes.

STATEMENT OF REASONS

BACKGROUND

Ray Samuel Chapman (the applicant) is 63 years old and worked for Tomago Aluminium Company Pty Limited (the respondent) between August 1998 and July 2022, as an operator at its aluminium plant. During the course of this period of employment, the respondent was initially insured by GIO, and then became self-insured from 1 July 2017.
The applicant sustained an injury to his left knee during the course of his employment with the respondent on 18 August 2007. He received compensation with respect to that injury pursuant to s 66 of the Workers Compensation Act 1987 (the 1987 Act), for 1% whole person impairment by way of a complying agreement dated 27 May 2009. The applicant sustained a further injury to his left knee during the course of his employment with the respondent on
11 June 2018, and he also sustained an injury to his right knee during the course of his employment with the respondent on 18 November 2018. The respondent concedes that these three injuries arose out of or in the course of his employment with it (in accordance with s 4 of the 1987 Act), and that his employment was a substantial contributing factor to the injuries occurring (in accordance with s 9A of the 1987 Act).
The applicant in addition alleges that during the course of his employment with the respondent, he performed duties requiring extensive periods of walking, standing, crouching, squatting, negotiating stairs, and negotiating uneven ground. He alleges that as a result, he has sustained a fourth injury in the nature of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with s 4(b)(ii) of the 1987 Act. The respondent in its interests as self-insurer disputes this alleged injury.
The applicant made a claim pursuant to s 66 of the 1987 Act by letters dated 8 August 2022, upon both the respondent in the interests of GIO and the respondent in its interests as self-insurer. The claim alleged that the applicant suffered from 33% whole person impairment and it relied upon the accepted injuries that occurred on 18 August 2007, 11 June 2018,
18 November 2018, as well as the disputed injury referred to in paragraph 3 above (which the parties agree would be deemed to have occurred on 8 August 2022 in accordance with
s 16 of the 1987 Act). In response to that claim, the respondent in its interests as self-insurer issued a notice denying liability for the claim under s 78 of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act) and disputing that the applicant had sustained an injury pursuant to s 4(b)(ii) in the form of an aggravation, acceleration, exacerbation or deterioration of a disease due to the nature of his employment duties, therefore also disputing that he was entitled to any compensation whatsoever regarding such an injury.
By an Application to Resolve a Dispute (ARD) filed in the Personal Injury Commission (Commission), the applicant claims compensation pursuant to s 66 of the 1987 Act relying upon the injuries which he sustained on 18 August 2007, 11 June 2018, and 18 November 2018, as well as the disputed injury which would be deemed to have occurred on 8 August 2022. Any impairment resulting from the accepted injuries on 18 August 2007, 11 June 2018, or 18 November 2018, is a matter for Medical Assessment, but before the relevant referral can be made, the Commission needs to determine liability with regard to the disputed injury which would be deemed to have occurred on 8 August 2022. If the injury is found, it would be added to the Medical Assessment referral.

ISSUE FOR DETERMINATION

The parties therefore agree that the only issue in dispute is as follows:
(a) did the applicant sustain an injury in the form of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with s 4(b)(ii) of the 1987 Act with a deemed date of 8 August 2022, due to the nature of his employment duties with the respondent.

PROCEDURE BEFORE THE PERSONAL INJURY COMMISSION

I am satisfied that the parties to the dispute understand the nature of the application and the legal implications of any assertion made in the information supplied. I have used my best endeavours in attempting to bring the parties to the dispute to a settlement acceptable to all of them. I am satisfied that the parties have had sufficient opportunity to explore settlement and that they have been unable to reach an agreed resolution of the dispute.
The dispute was listed for conciliation/arbitration before the Commission on 2 June 2023. On that occasion, Mr Allen Parker of counsel appeared for the applicant, instructed by
Mr Watson. The applicant was present. Ms Nicole Compton of counsel appeared for the respondent in the interests of GIO, instructed by Mr Newell, and Mr Bennett was also present representing GIO. Mr Tom Grimes of counsel appeared for the respondent in its interests as self-insurer, instructed by Ms Bray. A number of employees of the respondent and/or self-insurer were also present, being Mr Treyvaud, Mr Noon, Ms McKee, and Ms Britt. The conciliation/arbitration was conducted by way of a MS Teams link.
As the dispute was unable to be resolved, it proceeded to an arbitration hearing. The issue to be determined (see paragraph 6 above) was agreed upon, and the following additional matters were agreed:
(a)    no objection was taken to the admission into evidence of all documents lodged with the Commission by each party;
(b)    no matter what my determination was in relation to the issue to be determined, there would be a remittance to the President for referral to Medical Assessment in relation to the applicant’s injury on 18 August 2007, for assessment with respect to the left lower extremity (knee) and scarring (TEMSKI), with all documents before me also to be referred to the relevant Medical Assessor - the referral would also contain a notation that the applicant had already received compensation for 1% whole person impairment in relation to this injury by way of a complying agreement dated 27 May 2009 (at page 199 of the ARD);
(c)    no matter what my determination was in relation to the issue to be determined, there would be a remittance to the President for referral to Medical Assessment in relation to the applicant’s injury on 11 June 2018, for assessment with respect to the left lower extremity (knee) and scarring (TEMSKI), with all documents before me also to be referred to the relevant Medical Assessor;
(d)    no matter what my determination was in relation to the issue to be determined, there would be a remittance to the President for referral to Medical Assessment in relation to the applicant’s injury on 18 November 2018, for assessment with respect to the right lower extremity (knee) and scarring (TEMSKI), with all documents before me also to be referred to the relevant Medical Assessor, and
(e)    should I determine the issue that I need to determine in favour of the applicant, there would also be a remittance to the President for referral to Medical Assessment in relation to the applicant’s injury on 8 August 2022 (being an occupational disease due to the nature and conditions of employment which the parties agree would be deemed to have occurred on that date), for assessment with respect to the left lower extremity (knee), right lower extremity (knee), and scarring (TEMSKI), with all documents before me also to be referred to the relevant Medical Assessor - the referral would also contain a copy of my Certificate of Determination and its accompanying reasons.

EVIDENCE

Documentary evidence

The following documents were in evidence before the Commission and considered in making this determination:
(a)    the ARD and attached documents;
(b)    the Reply lodged by the respondent in the interests of GIO (GIO Reply) and attached documents;
(c)    the Reply lodged by the respondent in its interests as self-insurer (self-insurer Reply) and attached documents;
(d)    the Application to Admit Late Documents lodged by the applicant and dated
20 April 2023 (applicant’s AALD), and attached documents;

(e) the Application to Admit Late Documents lodged by the respondent in the interests of GIO and dated 25 May 2023 (GIO AALD), and attached documents, and
(f) the Application to Admit Late Documents lodged by the respondent in its interests as self-insurer and dated 26 May 2023 (self-insurer AALD), and attached documents.

Oral evidence

No oral evidence was given by the applicant or any other witness at the arbitration hearing.

Applicant’s evidence

Much of the evidence in the ARD relates to the accepted injuries sustained by the applicant on 18 August 2007, 11 June 2018, and 18 November 2018. I have considered the entirety of the evidence and will only be detailing the evidence relevant to the issue that I need to determine.
First, the applicant has provided a statement dated 14 June 2022 (page 1 of the ARD).
The applicant began working for the respondent in August 1998 as an operator. He generally worked 48 hours every eight days in four 12 hour shifts. His duties involved:
(a)    changing the anodes in the aluminium pots (16 anodes in each pot and 140 pots in each room);
(b)    tapping the metal out of the pots into a large ladle;
(c)    wearing very heavy equipment for personal protection;
(d)    putting additives into the pots and taking temperatures, and
(e)    using machinery - including forklifts, gantry cranes, buggies and trailers.
He says:
“I spend most of my day on my feet and walk many kilometres each day on the concrete floors. It's also a half kilometre walk to the crib room. I get an hour lunch break each shift. I also have to negotiate lots of stairs and uneven ground. My work also involved long periods of standing, crouching and squatting. All of this caused my knees to ache by the end of the day”.
The applicant explains that he initially injured his right knee when he worked at Mineral Deposits in around 1987, but “made a full recovery”. He then describes his accepted left knee injury while he was employed by the respondent on 18 August 2007, following which he needed surgery on 15 February 2008. He returned to work for the respondent on
2 April 2008 and still had intermittent pain, but did not require any further treatment and was able to perform his full duties with the respondent. He says that his “left knee was stable and I did not have any stiffness or swelling”.
Then, in 2014, he consulted with Dr Harbury as both of his knees were aching. He was advised to lose weight, and he lost 35 kg. He continued to perform his full duties with the respondent.
The applicant then describes his accepted left knee injury while he was employed by the respondent on 11 June 2018. He took one night off work and was given light duties (doing cleaning work) to perform with the respondent. He saw Dr Harbury again, and underwent exercise physiology and hydrotherapy. He says that his left knee became “very unstable and weak and I had needed to use a walking stick to prevent falling over”.
The applicant then describes his accepted right knee injury while he was employed by the respondent on 18 November 2018. Following this injury, he continued to perform his cleaning duties with the respondent.
The applicant alleges that he was told by the respondent that he needed to get his “knees fixed or I wouldn’t have a job”. He stopped working for the respondent in March 2019 and underwent a left knee replacement under Dr Osborne on 21 May 2019 as well as a right knee replacement also under Dr Osborne on 13 August 2019. He then returned to work for the respondent on 10 December 2019. He returned to work with a certificate allowing him to work his full duties, which he says that he needed to obtain as he financially needed to return to work, even though he was not really fit for his full duties. On his return to work however, the respondent did enforce some restrictions on his duties, meaning that he only performed “floor work”.
He says:
“I continued at work but was continuing to have trouble with both my knees and found that my work duties continued to aggravate them…By early 2021 I noticed that I had pain in my right knee after I had been on my feet for a while at work and had numbness around the right knee. It would click when I went up or down steps and stairs and it would swell, particularly after walking. This was, as I say, worse at work because I was walking all the time on concrete. At that stage I was tying to do 12 hour shifts, being two day shifts and two night shifts and then having four days off to rest…My left knee was painful in much the same way but I had slightly better movement in it. Because of the condition of my knees I could not squat or kneel and if I had to get down on the floor I needed to push up with my hands to rise again…There are a lot of steps at work and I found these difficult so I was taking them slowly and being careful”.
The applicant saw Dr Osborne again on 7 February 2022 and advises that by that time, “I found that my right knee was swelling up and I could hardly bend it and both knees were very sore after a day at work”.
The applicant has provided a further statement dated 9 March 2023 (page 13 of the ARD). In that statement, he advises that the condition in both of his knees is unchanged, but that he ceased working with the respondent in July 2022. The statement also annexes four photographs of the respondent’s plant to “show the size and scale and also the difficult working conditions”. The applicant confirms the heavy nature of his work with the respondent and his need to walk long distances on concrete floors to perform that work, which generally involved him in being on his feet for 12 hours per shift, or 16 hours per shift if he worked overtime.
The applicant relies on medical evidence from Dr Burrow. The doctor’s first report dated
1 November 2019 is at page 32 of the ARD.
The doctor takes a history of the applicant working for 21 years “as a pot line operator at Tomago Aluminium where he does mixed labour-crane driver and forklift driver, smelting aluminium and changing anodes, working on a heavy concrete floor and having to regularly walk over many stairs many times per shift”. The doctor also takes a history of the applicant’s right knee injury at Mineral Deposits, as well as his left knee injuries while working for the respondent in 2007 and in June 2018. He notes the following radiology results:
(a)    an oblique tear through the medial meniscus with degenerative changes of the medial compartment of the left knee – on 6 December 2007;
(b)    both knees showing moderate arthropathy - on 8 October 2014;
(c)    left knee arthritis – on 26 June 2016, and
(d)    right knee arthritis - on 14 December 2018.
The doctor also notes the knee replacement surgeries that the applicant underwent under
Dr Osborne in May 2019 and August 2019.
On examination, the doctor finds reduced range of movement in both knees.
The doctor opines:
“It is my opinion that his employment with Tomago Aluminium working on hard concrete floors for 21 years, in conjunction with twisting incidents described in this report, is the significant contributing factor to the development of his arthritis.”
The doctor also acknowledges however that the applicant’s employment with the respondent was not the only factor in the development of his arthritis, specifically mentioning the applicant’s right knee injury at Mineral Deposits. The doctor does however note that the applicant had no history of familial arthritis, when discussing Dr Smith’s opinion (to be detailed later) that knee arthritis is a familial inherited condition. The doctor explains:
“knee arthritis generally is constitutional and there is often a background familial history, however that is often inseparable from the natural degeneration that occurs
with life, age and obesity but also the traumas that occur particularly by way of sport and occupation.”

The doctor’s next report is dated 9 September 2020 and is at page 37 of the ARD. The doctor notes that the applicant’s knee (especially the left) symptoms had improved since he last saw him, but he also notes:
“Since last seen, when Mr Chapman was not working, he returned to work with Tomago on the pot line as an Operator, mostly doing walking and light duties on a full-time basis. He walks the floor on a 12 hour shift. His knees become painful, particularly the right on occasion and he takes Ibuprofen.”
The doctor details the applicant’s current symptoms as:
“Mr Chapman has seen improved symptoms since I saw him last. The left knee pain is
significantly improved. The right knee is slightly more problematical. He can now walk about 5km 'easily on the flat', can negotiate uneven ground carefully and can manage 20 stairs easily. He cannot kneel.”
The doctor confirms his opinion as:
“It is my opinion that his employment with Tomago over 21 years has been a significant factor in the development of his bilateral knee arthritis. There are other factors as well including constitutional and a previous injury to the right knee which required arthroscopy for a 'torn cartilage' 25-35 years ago…There is, however, no history of familial arthritis.”
The doctor’s next report is also dated 9 September 2020 and is at page 42 of the ARD. The report essentially provides assessments as to the applicant’s whole person impairment in both his knees. Significantly, the doctor deducts 10% from his assessments (pursuant to
s 323 of the 1998 Act) in respect of “constitutional wear related to obesity”.
Finally, the doctor provides a report dated 16 September 2020, in which he advises:
“You are referred to my previous reports of 01/11/19 and 09/09/20. Mr Chapman suffered twisting injuries to his left knee on 18/06/07 and 11/06/18 and then to his right knee on 18/11/18, when his left knee gave way. These incidents together with 21 years of working on hard concrete floors at Tomago Aluminium are responsible for his bilateral knee arthritis and need for knee replacements. Impairments should therefore be combined.”
The applicant also relies upon medical evidence from Dr Hopcroft, whose report dated
6 September 2022 is found at page 211 of the ARD.
The doctor initially takes a history of the applicant’s right knee injury at Mineral Deposits, following which he needed medial meniscal surgery.
The doctor then notes that the applicant began working for the respondent in August 1998, and that his employment duties included “walking extensive distances through the six massive sheds that comprise the potlines”. He worked 12 hour shifts which would leave him “exhausted because of the protracted walking activities”. He had to negotiate staircases, work on uneven ground, and often undertake protracted standing, crouching and squatting.
The history taken by the doctor continues:
(a)    the applicant sustained a left knee injury during the course of his employment with the respondent on 18 August 2007, following which he underwent surgery with Dr Mitchell requiring a 50% excision of the medial meniscal tear;
(b)    the applicant returned to work “but continued to notice a slow deterioration in both knees” - he required radiological investigation in October 2014 which showed:
(i)with the right knee – moderate arthropathy of the medial compartment as well as mild patellofemoral joint arthropathy; and
(ii)with the left knee – advanced medial compartment arthropathy with asymptomatic loss of joint space and periarticular calcification as well as mild to moderate lateral compartment and patellofemoral arthropathy;
(c)    the applicant continued with conservative treatment but then suffered a further twisting injury to his left knee during the course of his employment with the respondent (presumably the 11 June 2018 injury) - he was then referred to
Dr Harbury who recommended bilateral knee replacements;
(d)    those bilateral knee replacements were eventually performed by Dr Osborne in May 2019 and August 2019, and
(e)    the applicant continued to have recurrent pain and swelling in his knees and consulted with Dr Osborne again in February 2022.
On examination, the doctor finds:
(a)    the applicant walked moderately well but with a broadbased gait;
(b)    the applicant could only crouch to 130° of loaded knee flexion;
(c)    the applicant had an excellent range of movement of his left knee joint from full extension to 120° of flexion, with a mild valgus varus laxity, and
(d)    with the right knee, the applicant had “quite a large effusion with a positive patella tap, no cruciate or collateral ligament laxity, but a range of movement from full extension to 90° only”.
The doctor reviews medical reports from Drs Burrow, Wallace, Machart and Smith, as well as many radiological reports. He opines that the applicant’s many years of work with the respondent which involved protracted walking and standing led to a significant deterioration in the functioning of both his knees. He states:
“There is no doubt that this patient's meniscal surgery contributed significantly to the
development of the osteoarthritis in both knees, but that the protracted standing and walking, that is the nature and conditions of his work, have accelerated the deterioration in his knee joint function, and the injuries suffered as detailed contributed to the acute on chronic changes that led to the diagnosis of his requirement to proceed to bilateral knee joint replacement surgery.”
The doctor concedes the applicant’s obesity hastened the deteriorating function in both of his knees, but concludes:
“I believe the frank injury arising in this patient's employment has been the substantial
contributing factor to his knee joint deteriorating function, and that his employment has
been the main contributing factor to the aggravation, acceleration, exacerbation and
deterioration of his bilateral knee joint function…There is no suggestion that this patient was a shirker or tried to avoid work, and the protracted activities undertaken with extended shifts at work over many years have been the significant contributing factor to his requirement to ultimately undergo bilateral total knee joint replacement surgery, triggered by the acute changes in the meniscal cartilages as detailed.”
The ARD contains medical reports from Dr Mitchell dated 30 January 2008 (at page 122) and 25 February 2008 (at page 123), and from Dr Wallace dated 13 February 2009 (page 203). These reports confirm that the applicant sustained a medial meniscal tear to his left knee in the injury on 18 August 2007 for which he underwent arthroscopic surgery. The records otherwise do not assist me with the issue that I need to determine.
The ARD also contains a number of medical reports from Dr Harbury. These reports are mainly reports from a treating specialist to a referring general practitioner, and as a result do not in their nature provide specific opinion evidence directed to the issue that I need to determine. There are however some comments that I do find relevant:

(a)    in the doctor’s 20 November 2014 report (at page 125), he diagnoses bilateral knee arthritis but advises against immediate knee replacement surgery due to the applicant’s weight - he takes the following relevant history:
“He works on his feet all day at the Tomago Smelter. He's here to see
about both his knees. They are both painful end they take turns at being worst. He has anteromedial anterior knee pain. This is worse with wejght bearing and by 10am it's causing him significant pain. He also gets some night and rest pain depending upon his activities. He has to sit down on a stool most of the day at work. They crunch and grind. He has a feeling of catching and pseudo locking and they are weak with twisting”;
(b)    in the doctor’s 10 July 2018 report (at page 126), he notes that after the applicant had lost weight, he had been able to “work normally without concern at his normal duties”, but that his left knee injury on 11 June 2018 had “stirred up his knee” - he recommends the applicant avoiding “prolonged ambulation or rough ground/heavy work”;
(c)    in the doctor’s 22 August 2018 report (at page 128), he notes that the applicant was performing selected duties at work, mainly involving operating a crane;
(d)    in the doctor’s 31 October 2018 report (at page 131), he notes that at that time the applicant was tolerating his work duties even though they were “somewhat solitary”;
(e)    in the doctor’s 21 November 2018 report (at page 132), he advises that the applicant told him that the applicant’s work activities were “apparently beyond what he can safely do” - he also advises that he will not get involved in dealings with the respondent regarding the suitability of those work activities;
(f)    in the doctor’s 6 December 2018 report (at page 134), he advises that the applicant was then working in his “previous working area” and was “comfortable on the flat for short distances but still struggles with stairs due to pain and instability”; and
(g)    in the doctor’s 28 February 2019 report (at page 237), he confirms that the applicant has decided to proceed with a left total knee replacement – he also suggests that:
“It is not guaranteed, but a successful knee replacement will aim to return to all facets of his previous occupation excepting very strenuous activity. Squatting, kneeling etc may be beyond him but this remains to be seen”.

The ARD further contains a number of medical reports from Dr Osborne. These reports are mainly reports from a treating specialist to a referring general practitioner, and as a result do not in their nature provide specific opinion evidence directed to the issue that I need to determine. There are however some comments that I do find relevant:
(a)    in the doctor’s 21 March 2019 report (at page 239), he describes the applicant as “markedly disabled by osteoarthritis in his left knee, his left knee has been brewing for many years”, and he opines that the injury in June 2018 “markedly exacerbated him”;
(b)    in the doctor’s 27 June 2019 report (at page 242), he describes the applicant as “doing terrifically well” and without significant pain, following his left total knee replacement, and
(c)    in the doctor’s 19 September 2019 report (at page 244), he explains that he is happy with the early outcome of the applicant’s right total knee replacement, although the applicant has a “little bit of pain” behind the knee.
Finally, the ARD contains certificates of capacity and clinical notes. I have considered these records but do not believe that they assist me in relation to the issue that I need to determine. I will refer to them further if directed to specific records during the parties’ submissions.

Respondent’s evidence

I have considered the evidence relied upon by the respondent in the interests of GIO. I only find the reports of Dr Machart to be particularly relevant to the issue that I need to determine, as those reports (unlike the remainder of the evidence) provide specific opinions in this regard. I will refer to other evidence if directed to that evidence during the parties’ submissions.
Dr Machart has provided two reports.
The first report is dated 11 November 2021 and found at page 188 of the ARD.
The doctor takes a history of the applicant’s injuries on 18 August 2007, 11 June 2018, and 19 November 2018, as well as the applicant’s right knee injury at Mineral Deposits. He does not take a description of the applicant’s general employment duties except to say:
“The job consisted of changing anodes that were operated by a crane. He was on his feet most of the time.”
On examination, he finds both knees physiologically valgus, with mild swelling, well-healed scars, and limited flexion.
The doctor reviews various medical reports and provides diagnoses:
(a)    a left knee meniscal tear probably caused by the injury on 18 August 2007, the surgery for which increased the progression of osteoarthritis - the injury on
11 June 2018 then aggravated the left knee;
(b)    the “predominant factor” with regard to the right knee was the applicant’s arthroscopy and meniscectomy following the injury at Mineral Deposits, and
(c)    both knees were affected by constitutional osteoarthritis.
In relation to the issue that I need to determine, he opines:
“I did not see contribution from nature and conditions of employment. The claim was
for nature or conditions of employment causing trauma to each knee. There was no
evidence for that to be the case. Such was not part of the narrative. Such was not part
of education for orthopaedic surgeons where osteoarthritis is taught as caused by
walking on hard surfaces.”
Dr Machart’s second report is dated 19 May 2023 and found at page 1 of the GIO AALD. The report was prepared following a solicitors’ request and did not follow a further examination of or history taking from the applicant. In the report, the doctor adds a further opinion:
“I did not see contribution from nature or conditions of employment, as walking on
concrete floor. This is something that the regular knee should be able to withstand and
does not cause additional structural injury or identifiable trauma.”
I have also considered the evidence relied upon by the respondent in its interests as self-insurer. I only find the reports of Dr Smith to be particularly relevant to the issue that I need to determine, as those reports (unlike the remainder of the evidence) provide specific opinions in this regard. I will refer to other evidence if directed to that evidence during the parties’ submissions.
Dr Smith has provided five reports.
The first report is dated 22 January 2019 and found at page 139 of the ARD.
In the report, the doctor does not take any history regarding the nature of the applicant’s employment duties with the respondent, but he does take a history of the applicant’s injuries on 18 August 2007, 11 June 2018 and 19 November 2018. Further, in relation to the applicant’s treatment with Dr Harbury in 2014, the doctor somewhat confusingly notes:
“He said in 2014 he had trouble with depression and anxiety and was referred to
Dr Harbury, Orthopaedic Surgeon, to discuss his knees. His knees settled not long after this discussion. He was told he was too young for knee replacements.”
The doctor reviews radiology in relation to only the applicant’s left knee, which he notes described triple compartment osteoarthritis. On examination, the doctor finds no hyperextension, 7% of varus deformity, and flexion to 110° with crepitus in the right knee; and no hyperextension and flexion to 105° in the left knee.
The doctor opines that the 11 June 2018 injury aggravated the applicant’s pre-existing left knee osteoarthritis, but that the symptoms emanating from the aggravation would have resolved within three weeks at most. He considers that the applicant’s symptoms when he examined the applicant were no longer a result of the aggravation and that the then proposed left knee replacement was to treat the applicant’s underlying familial constitutional osteoarthritis.
In relation to how the applicant’s osteoarthritis was likely to be aggravated, the doctor explains:
“The prognosis is for his left knee osteoarthritis to continue to be aggravated from
time to time with a variety for activities on his part. The knee osteoarthritis will cause
eventually pain with every single weight-bearing episode. He has a similar problem
in his right knee, which will also become severe as the years pass…His bilateral knee osteoarthritis was always going to become worse with the passage of the years, whether he worked, whether he did not work and no matter what work he did or did not engage in.”
Dr Smith’s second report is dated 21 April 2020 and found at page 100 of the ARD.
The doctor now obtains a slightly more expansive history regarding the nature of the applicant’s employment duties with the respondent, by describing the applicant as “doing heavy manual work” for the respondent, and by referring to the history of the applicant’s employment duties contained in Dr Burrow’s 1 November 2019 report.
He however confirms his opinions that the applicant’s knee arthritis “was completely unrelated to his employment, as it was a familial inherited condition seen in about 20% of the population of Caucasian origin”, as well as that the applicant had “had a number of work aggravations which would not have made his arthritis any worse than it was going to get with the passage of time”. He then provides the following further opinion:
“The arthritis occurs in people from all walks of life and deteriorates slowly with the
passage of years. It does not matter what activities one engages in or how many
exacerbations one as from one's knee arthritis. The condition is totally unrelated to
employment. I can recall rather well, seeing a 55-year-old woman, some 25 years
ago now, who had contracted polio at almost 1 year of age. She was in an iron lung
until she was nine and up until the age of 55, had never walked a step or run or
jumped or knelt or squatted. She had been wheelchair-bound her entire life, but she
still had severe, painful and stiff osteoarthritis of the knees, much like Mr Chapman.”
On examination, the doctor finds no hyperextension and flexion to 95° with crepitus in the right knee; and 10° hyperextension and flexion to 110° in the left knee.
On specific questioning regarding whether the applicant’s employment with the respondent was the main contributing factor to the contraction, aggravation, acceleration, exacerbation, or deterioration of a pre-existing disease, the doctor provides the following summary of his opinion:
“There is, in my opinion, no likelihood that his employment was the main contributing
factor to him developing his bilateral knee osteoarthritis. It is possible that he had
aggravations to his knee arthritis on one side or another, with activities at work or at
home. Those aggravations would have resolved of their own accord and left no
disability of themselves. His knees would have continued to deteriorate whether or
not he had any aggravations from time to time, either with domestic activity,
recreational activity or employment activity…In my opinion his employment is not the main contributing factor to a deterioration of pre-existing osteoarthritis. The aggravations would have resolved and left no disability of themselves.”
Dr Smith’s third report is dated 31 December 2020 and found at page 107 of the ARD.
In relation to the history obtained by the doctor, he says that the applicant’s “employment at the smelter for 21 years was described”, without going into any further detail.
He confirms his previously expressed opinions and maintains that the applicant’s bilateral knee arthritis is a familial inherited condition which the applicant would have suffered “whether he worked or whether he did not work and no matter what work he engaged in”. Importantly however, he also explains:
“I am aware of the letter of Dr Burrow. In my opinion, there is no relationship between
his employment and his knee osteoarthritis. A number of activities are well-known as
aggravating factors to the development of pain from knee arthritis, such as kneeling,
squatting, running, jumping and working in confined spaces, snow and waterskiing. In
fact, any activity that places stress on the knees is likely to aggravate knee arthritis.
The knee osteoarthritis gets worse with the passage of time. These aggravations do
not make the knee arthritis get worse.”
Dr Smith provides a fourth report dated 11 October 2022 (at page 54 of the ARD), in which he is asked to review documentation and provide further opinions. It does not appear that any further examination of the applicant or history taking from him, occurred.
The doctor does not alter his previously expressed opinions, and he confirms that he agrees with Dr Machart’s opinions that “knee arthritis is not a consequence of the nature and conditions of his employment” and that “none of the impairment that one can assess consequent to his knee arthritis is a consequence of his employment”.

Dr Smith’s fifth report dated 5 May 2023 (at page 1 of the self-insurer AALD) does not deal with the issue that I need to determine.

Applicant’s submissions

The applicant’s submissions have been recorded and I will not summarise them in detail.
The applicant first takes the Commission to his statements and submits that there is no issue taken by the respondent with respect to their accuracy. Having regard to the nature of the applicant’s employment duties (see paragraphs 14-15 above), it is “common sense” that those duties would cause wearing and tearing to his knees.
The applicant then takes the Commission to Dr Burrow’s opinions (especially those opinions outlined at paragraphs 27-28 and 31 above) and urges that they be accepted, especially considering the criticism that the applicant then embarks upon in relation to the opinions of Dr Smith (especially those opinions outlined at paragraphs 62, 64, and 67 above).
The applicant submits that those opinions “defies belief”, and that it is “nonsense to say” that arthritis is not affected by activity. The doctor explains that arthritis can be aggravated by activities, but does not explain his opinion as to how those aggravations resolve and as to how they do not make the arthritis worse. Further, the doctor is “completely wrong” when proposing a familial connection to the applicant’s arthritis.
In summary, Dr Smith’s opinions do not “relate in any common sense way to somebody doing hard work on concrete”.
The applicant then takes the Commission to Dr Hopcroft’s opinions and submits that they provide logical support to the applicant’s claim, and should be preferred to those of Dr Smith.
On questioning by the Commission as to whether there were any reports from treating practitioners specifically regarding causation, the applicant conceded that there were not, although Dr Harbury (see paragraph 42(a) above) did obtain a history of the applicant’s employment duties, and the difficulties that he was having performing them in late 2014. The applicant submitted that the reports from the treating practitioners in the ARD were not directed at legal issues, but rather at curing the applicant.

Respondent’s submissions

The respondent’s submissions have been recorded and I will not summarise them in detail.
Mr Grimes commenced on behalf of the respondent in its interests as self-insurer.
It was submitted that the applicant’s injuries on 18 August 2007, 11 June 2018, and
18 November 2018 were the cause of his knee conditions, and that there was no evidence from his treating doctors attributing any of his knee symptoms to the nature and conditions of his employment. There was no evidence of any aggravation to his knee conditions that caused him to cease working in July 2022, and indeed there was no explanation as to why he then ceased work. This was described as a “glaring lack of evidence”.
On that background, the Commission was encouraged to accept the opinions of Drs Machart and Smith.
The Commission was specifically taken to the opinion of Dr Smith discussed at paragraph 67 above. It was submitted that, in relation to the aggravating factors referred to there by
Dr Smith, “none of them are at play in terms of the applicant’s allegations”. It was however then pointed out to the respondent by the Commission that there was evidence that the applicant’s employment duties involved kneeling, squatting, and working in confined spaces.
The Commission was then taken to the history of the applicant’s symptoms recorded by
Dr Burrow and discussed a paragraph 30 above. It was submitted that the history was in “direct contrast to what he alleges was happening to him at work”, and that the history revealed the applicant’s capacity to walk long distances and navigate stairs and uneven ground.
Ms Compton then made brief submissions on behalf of the respondent in the interests of GIO.
She recorded that GIO relied upon the opinions of Dr Machart, as well as the evidence of the applicant’s treatment following his injury on 18 August 2007, which revealed that he had made an “almost full” recovery from that injury in that he was able to return to his pre-injury duties from 2008. Ms Compton otherwise recorded that it was not appropriate for her to make specific submissions regarding the “nature and conditions claim”, as her client was not the insurer on risk for that claim.

Applicant’s submissions in reply

These submissions have also been recorded and I will not summarise them in detail.
The applicant submits:
(a) neither Dr Machart nor Dr Smith obtained a proper description of the applicant’s employment duties with the respondent, and
(b) in those circumstances, the effect of the opinion of Dr Smith discussed at paragraph 67 above is to support the applicant’s duties as being an aggravating factor to his osteoarthritis.

FINDINGS AND REASONS

Did the applicant sustain an injury in the form of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with s 4(b)(ii) of the 1987 Act with a deemed date of 8 August 2022, due to the nature of his employment duties with the respondent.

“Injury” is defined in s 4 of the 1987 Act as follows:
“In this Act: injury means:
(a)     personal injury arising out of or in the course of employment,
(b)     includes a ‘disease injury’, which means:
(i) a disease that is contracted by a worker in the course of employment but only if the employment was the main contributing factor to contracting the disease, and
(ii) the aggravation, acceleration, exacerbation or deterioration in the course of employment of any disease, but only if the employment was the main contributing factor to the aggravation, acceleration, exacerbation or deterioration of the disease, and
(c)     does not include (except in the case of a worker employed in or about a mine) a dust disease, as defined by the Workers’ Compensation (Dust Diseases) Act 1942, or the aggravation, acceleration, exacerbation or deterioration of a dust disease, as so defined.”
It is therefore for the applicant to establish that his employment duties with the respondent aggravated the osteoarthritis in both of his knees, and that the employment duties were the main contributing factor to the aggravation in this regard. The employment duties do not have to be the main contributing factor to the contraction or development of the osteoarthritis itself.
The definition of “main contributing factor” is discussed at length by Snell DP in AV v AW [2020] NSWWCCPD 9 (AV), where various authorities are reviewed and where the Deputy President summarises [at 77-78]:
“It follows that the test of ‘main contributing factor’ involves consideration of whether there were competing causal factors (both work and non-work related) of the aggravation, and whether on a consideration of relevant causal factors the employment represented the main contributing factor.
The following may be taken from the above:
(a) The test of ‘main contributing factor’ in s 4(b)(ii) is more stringent than that in s 4(b)(ii) in its previous form, which applied in conjunction with the test in s 9A. There will be one ‘main contributing factor’ to an alleged aggravation injury.
(b) The test of ‘main contributing factor’ is one of causation. It involves consideration of the evidence overall, it is not purely a medical question. It involves an evaluative process, considering the causal factors to the aggravation, both work and non-work related. Medical evidence to address the ultimate question of whether the test of ‘main contributing factor’ is satisfied is both relevant and desirable. Its absence is not necessarily fatal, as satisfaction of the test is to be considered on the whole of the evidence.
(c) In a matter involving s 4(b)(ii) it is necessary that the employment be the main contributing factor to the aggravation, not to the underlying disease process as a whole.”
I accept the evidence given in the applicant’s statements. There has been no suggestion or evidence that I should accept otherwise. The history given by the statements is consistent with the histories provided in the medical evidence, specifically the reports provided by
Drs Burrow and Hopcroft (see paragraphs 25 and 36 above), as well as the history provided in Dr Harbury’s 20 November 2014 report (see paragraph 42(a) above).
The respondent submits (see paragraph 83 above) that there is some inconsistency with the applicant being able to walk long distances and navigate stairs when he consulted with
Dr Burrow on 9 September 2020. This is however consistent with the employment duties that the applicant was required to perform after he returned work for the respondent on
10 December 2019. The applicant explains the difficulties that he had with those employment duties in his statement (see paragraph 21 above).
The applicant says (see paragraph 15 above) that his employment duties with the respondent involved him in walking many kilometres every day on concrete floors. Importantly, he also says that those duties involved negotiating lots of stairs and uneven ground, as well as long periods of standing, crouching and squatting.
The evidence is that he performed these duties in full from August 1998 until 11 June 2018, save for a period of around eight months after his injury on 18 August 2007. Then, between 11 June 2018 and 10 December 2019, the respondent provided him with lighter employment duties. After 10 December 2019, the applicant says that he was again working full duties but only “floor work”. He identifies however (see paragraph 21 above) that he was still on his feet at work long hours, he was still required to go up and down stairs, and he was still required to get into positions that would normally require squatting or kneeling.
I accept the applicant's submission (at paragraph 72) that the employment duties described by him, which were performed almost continually for 24 years, necessarily placed stress upon both his knees.
The applicant also does not identify any other significant personal activities that he was involved in that placed stress upon his knees, and nor does the medical evidence.
In relation to the medical evidence, it is unfortunate that there is no significant evidence specifically regarding the causation of the applicant’s knee conditions, from his treating doctors. I draw no inferences however in this regard. The medical evidence presented by the applicant from his treating doctors largely consists of reports they sent to each other regarding the treatment given to or needed by the applicant. Those reports would not be expected to be directed to causation issues.
The lack of this evidence from the applicant’s treating doctors is of course not fatal to his claim. I am however left to rely upon the opinions of four medical-legal specialists in order to determine the claim.
In this regard, I find the opinions expressed by Dr Hopcroft as being the most helpful, and I intend to give those opinions significant weight. In my opinion, the doctor obtains the most complete history of the applicant’s employment duties with the respondent (see paragraph 36 above), as he refers to long periods of walking, as well as negotiating stairs, walking over uneven ground, standing, crouching and squatting. The doctor was also the most recent medico-legal specialist to examine the applicant.
The doctor takes notice of the applicant’s injuries on 18 August 2007, 11 June 2018, and
18 November 2018, and he also takes notice of the applicant’s obesity. He is nevertheless clear in his opinions that (see paragraphs 39-40 above) the “nature and conditions of his work, have accelerated the deterioration in his knee joint function”, and that “his employment has been the main contributing factor to the aggravation, acceleration, exacerbation and deterioration of his bilateral knee joint function”.
The history obtained by Dr Burrow (see paragraph 25 above) is not quite as complete as that obtained by Dr Hopcroft, as it does not specifically refer to crouching and squatting duties.
The doctor however goes further in his opinions than Dr Hopcroft, explaining that knee arthritis is generally constitutional but inseparable from the degeneration that often occurs through trauma particularly sustained at work. He is consistent in his opinion (see paragraphs 27, 31, and 33 above) over a number of reports (including after he was provided with reports from Dr Smith) that the applicant’s injuries on 18 August 2007, 11 June 2018, and 18 November 2018, together with his employment duties that involved him working for many years on hard concrete floors, are “the significant contributing factor to the development of his arthritis” and “responsible” for its development.
In coming to his opinion, the doctor takes into account constitutional factors as well as the applicant’s right knee injury at Mineral Deposits.
In contrast, the histories obtained by Drs Machart and Smith (see paragraphs 48, 56 and 61 above) are scant to say the least. I do not believe that they have therefore expressed their opinions in a ‘fair climate’.
In ACW v ACX [2022] NSWPICPD 19, Snell DP summarised:
“51. In Paric No. 1 Samuels JA said:
‘It is a question of whether the hypothetical material put to the expert witnesses represents a fair climate for the opinions they expressed. I do not think there is any requirement that the matter put is precisely consonant with the material provided; and certainly it cannot be contended that there was no evidence upon which the opinions could be based.
Discrepancies may be fatal; in some cases even slight discrepancies may be fatal; in other cases even broad departures are not likely to affect the force of the expert opinion. Moreover, it is for the tribunal of fact to assess this factual basis.’
52. In Paric No. 2 the High Court said:
‘It is trite law that for an expert medical opinion to be of any value the facts upon which it is based must be proved by admissible evidence (Ramsay v. Watson [1961] HCA 65; (1961) 108 CLR 642). But that does not mean that the facts so proved must correspond with complete precision to the proposition on which the opinion is based. The passages from Wigmore on Evidence cited by Samuels J.A. in the Court of Appeal (Wigmore on Evidence, (1940) 3rd ed., vol.II, 680, p.800; 2 Wigmore, Evidence 680 (Chadbourn rev. 1979), p.942) to the effect that it is a question of fact whether the case supposed is sufficiently like the one under consideration to render the opinion of the expert of any value are in accordance with both principle and common sense.’
53. In Hancock v East Coast Timber Products Pty Ltd Beazley JA (as her Honour then was) discussed the above principles in the context of the Commission. The discussion remains applicable since the relevant commencement of the 2020 Act. Her Honour said:
‘82. Although not bound by the rules of evidence, there can be no doubt that the Commission is required to be satisfied that expert evidence provides a satisfactory basis upon which the Commission can make its findings. For that reason, an expert’s report will need to conform, in a sufficiently satisfactory way, with the usual requirements for expert evidence. As the authorities make plain, even in evidence-based jurisdictions, that does not require strict compliance with each and every feature referred to by Heydon JA in Makita to be set out in each and every report. In many cases, certain aspects to which his Honour referred will not be in dispute. A report ought not be rejected for that reason alone.
83. In the case of a non-evidence-based jurisdiction such as here, the question of the acceptability of expert evidence will not be one of admissibility but of weight. This was made apparent in Brambles Industries Limited v Bell [2010] NSWCA 162 at [19] per Hodgson JA.’”
Neither Dr Machart nor Dr Smith obtained a history of the applicant’s work with the respondent involving negotiating lots of stairs and uneven ground, as well as long periods of standing, crouching and squatting. I am not satisfied as a result that their opinions provide a satisfactory basis upon which I can make my findings. The weight that I intend to give those opinions is affected by the failure of the doctors to obtain a satisfactory history of the applicant’s employment duties.
In relation to Dr Machart, there is also in my opinion a failure by the doctor to consider whether the applicant’s employment duties aggravated or accelerated his underlying knee osteoarthritis. He opines (see paragraphs 51-52 above) that the osteoarthritis was not caused by walking on hard surfaces, but he fails to consider whether the osteoarthritis was aggravated or accelerated by either walking on hard surfaces, negotiating lots of stairs and uneven ground, or long periods of standing, crouching and squatting.
On the other hand, Dr Smith, while also opining that the applicant’s osteoarthritis was not caused by his employment duties, does consider the types of activities that would aggravate the arthritis.
This is unfortunately where Dr Smith’s lack of history taking from the applicant is most pronounced. The doctor identifies (see paragraph 67 above) activities that are well-known to aggravate the arthritis, such as kneeling, squatting, working in confined spaces, and in fact any activity that places stress on the knees. These of course are precisely the activities that the applicant performed almost continuously for 24 years during the course of his employment with the respondent. However, the doctor does not seem to appreciate this.
The doctor is consistent in his opinions (see paragraphs 59, 62, 64, and 67 above) that when the arthritis is aggravated, the aggravation resolves and leaves no disability of itself, and that when the arthritis is aggravated, the aggravation would not make the arthritis any worse than it was going to get with the passage of time. The arthritis will get worse no matter what activities or work the applicant engages in.
As pointed out to the respondent during its submissions however, it is my role to determine whether the applicant’s arthritis was aggravated by his employment duties, and not whether that aggravation has led to any ongoing disability, impairment, or lack of working capacity. If I find that the applicant’s arthritis was aggravated by his employment duties, I am finding that he has suffered an injury within s 4(b)(ii) of the 1987 Act only. Whether that injury has led to any permanent impairment is a question for a Medical Assessor. Whether that injury has led to a lack of working capacity is not an issue that is before me to determine. I therefore reject the respondent’s submission (see paragraph 80 above) regarding the necessity for there to be evidence as to why the applicant ceased working in July 2022.
In relation to my role in this dispute, I refer to the decision of Roche DP in Jaffarie v Quality Castings Pty Limited [2014] NSWWCCPD 79 (Jaffarie), which clarified the approach of the then Workers Compensation Commission following the Court of Appeal decision in Bindah v Carter Holt Harvey Wood Products Australia Pty Limited [2014] NSWCA 264.
In Jaffarie, Roche DP stated:
“in a claim for lump sum compensation, the physical consequences of the injury (in relation to the assessment of whole person impairment as a result of the injury) are not within the exclusive jurisdiction of the Commission. They are within the exclusive jurisdiction of the AMS. That is so even if the matter also involves a disputed claim for weekly compensation and disputes about causation, which the Commission has determined” [at 250];
“‘the nature of the injury’ is a matter for the Commission to determine. This is consistent with Emmett JA’s statement at [111] that it is for the Commission ‘to determine whether a worker has suffered an injury within the meaning of s 4 of the [1987] Act’” [at 57]; and
“In Bindah, the parties agreed that the worker had received an injury and, as Emmett JA observed at [119], the Arbitrator did not ‘need’ to make a determination about the precise nature of the injury. However, consistent with the reasoning of Meagher JA, when the Commission, either by consent or after a contest, has determined the nature of the injury, it is for the AMS to determine the degree of whole person impairment that has resulted from that injury. While it is open to an AMS to determine that no whole person impairment has resulted from the agreed or found injury (Austin; Haroun), it is not open to an AMS to find that the worker suffered no injury or has suffered a different injury to that found or agreed” [at 259].

In the circumstances in Jaffarie, the Commission was required to refer the claim for lump sum compensation to medical assessment notwithstanding its finding that the effects of the applicant’s injury in that case had ceased.
In the circumstances, I find that the opinion expressed by Dr Smith regarding the types of activities that would aggravate the applicant’s arthritis assists me in determining that the arthritis was aggravated by his employment duties with the respondent. This is consistent with the evidence in the applicant’s statements (which I have accepted) and it is also consistent with the opinion expressed by Dr Hopcroft (whose opinion I have given the most weight among the medico-legal specialists who have examined the applicant, having regard to his correct history taking).
In summary therefore, after reviewing and evaluating the evidence presented in its entirety, I am comfortably satisfied that the applicant aggravated his arthritis condition while performing his normal employment duties with the respondent, and that these duties were the main contributing factor in the aggravation of the arthritis. In weighing up the competing causative factors as referred to in AV, it seems to me that there is only one factor involved in the aggravation of the arthritis due specifically to the nature of the applicant's employment duties with the respondent, that being those employment duties. The applicant has suffered other aggravations of his arthritis (including as a result of his injuries on 11 June 2018 and 18 November 2018) but they are separate aggravations, and not factors to be taken into account when considering if there were any other factors involved in the specific aggravation of the arthritis that I have found was caused by his employment duties with the respondent. In my opinion, it is only the specific aggravation in this regard that needs to have employment as its main contributing factor.

SUMMARY

I therefore find that the applicant sustained an injury in the form of an aggravation, acceleration, exacerbation or deterioration of a disease in accordance with s 4(b)(ii) of the 1987 Act with a deemed date of 8 August 2022, due to the nature of his employment duties with the respondent.
The determination of the applicant’s whole person impairment as a result of that injury will be remitted to the President for referral to a Medical Assessor (together with the determinations of the applicant’s whole person impairments as a result of his other injuries on 18 August 2007, 11 June 2018, and 18 November 2018). The terms of the referrals are to be in accordance with the parties’ agreements noted at paragraph 9 above.

[2023] NSWPIC 307

28 June 2023