CERTIFICATE OF DETERMINATION OF MEMBER  	
	
Citation:	Casey v HammondCare [2024] NSWPIC 449	
		
APPLICANT:	Lee-Anne Casey	
		
RESPONDENT:	HammonCare	
		
Member:	Parnel McAdam	
		
DATE OF DECISION:	19 August 2024	
		
CATCHWORDS:	WORKERS COMPENSATION - Aggravation of disease; applicant injured knee when assisting a patient during home care; significant history of investigations into knee spanning 14 years; admissibility of Injury Management Consult (IMC) report into evidence; consideration of Workers Compensation Guidelines; AV v AW and Taylor v J & D Stephens Pty Ltd considered; Held – IMC acted outside of Workers Compensation Guidelines and was acting as an advocate for insurer; report not admitted; award for the respondent.
	
determinations made:	The Commission determines:
1.	Award for the respondent. 

STATEMENT OF REASONS
BACKGROUND
1.	Ms Casey has worked in community care for an extensive part of her working life. She was employed by HammondCare (the respondent) from around 2017 working on a part time basis for about 20 hours per week. The role was quite physical, involving assisting people with their general life needs, and completing domestic tasks. 
2.	On 15 June 2022, a specific incident occurred at a patient’s home. Ms Casey was walking the patient to the toilet, when they lost balance and fell, landing directly on Ms Casey’s knee. Ms Casey was able to complete her shift, although on the next day her leg was swollen and she was unable to weight bear. 
3.	Ms Casey requires a knee replacement, and brought a claim to the Personal Injury Commission (Commission) for medical expenses seeking the cost of that procedure be paid for. 
ISSUES FOR DETERMINATION
4.	The parties agree that the following issues remain in dispute:
(a)	whether the applicant suffered an aggravation of pre-existing osteoarthritis, to which employment was the main contributing factor; 
(b)	whether the aggravation continues or has ceased, and 
(c)	whether surgery claimed is as a result of injury or due to pre-existing factors. 
5.	The respondent accepts that the applicant suffered a soft tissue injury to the right knee. 
PROCEDURE BEFORE THE PERSONAL INJURY COMMISSION
6.	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.  
EVIDENCE
Documentary evidence
7.	The following documents were in evidence before the Commission and considered in making this determination: 
(a)	Application to Resolve a Dispute (Application) and attached documents;
(b)	Reply and attached documents; 
(c)	Application to Admit Late Documents dated 30 July 2024, and
(d)	Application to Admit Late Documents dated 31 July 2024. 
8.	I have considered all of the material filed by the parties in the Application and Reply. I note a large volume of material was filed under the cover of two Applications to Admit Late Documents, traversing some 1,000 pages, which are largely clinical notes. During submissions, the parties referred me to particular aspects of that evidence which I have considered. I will discuss the relevant evidence briefly below. 
The applicant’s statement
9.	The applicant acknowledges the previous history of injury to her left knee, which resulted in a knee reconstruction. She states that after the surgery she recovered fully. She considered herself to be fit, healthy and capable of handling the physical demands on her employment. 
10.	Ms Casey sets out her employment duties which revolve around assisting patients with daily activities. On 15 June 2022, the applicant was assisting a patient who suffered a transient ischaemic attack, who fell and landed directly on the applicant’s knee, causing pain. The next day the applicant woke up with significant pain and swelling. Further incidents occurred during a return to work. 
11.	The applicant states that following the injury, her pre-existing arthritis worsened, and that she was fully capable of performing her work duties before her injury. The applicant sets out the pre-existing treatment to her knee, including scans about three months prior to the work incident. The applicant goes on to set out why she disagrees with the s 78 notice issued by the respondent. 
Report of Dr Bodel
12.	The applicant relies on the medicolegal opinion of Dr Bodel. He takes a history of work with the respondent for about seven years, on the background of aged care work in various activities for a total of about 23 years. The history of injury, caused by a resident suffering a transient ischaemic attack, is consistent with that recorded in the applicant’s statement. 
13.	Dr Bodel records that it is “noteworthy” that she had a previous total knee replacement on the left hand side. He conducts an examination of Ms Casey, and then provides commentary on the relevant documentation, including the report of Dr Machart on whom the respondent relies. In relation to that report, in which Dr Machart opined that injury was a soft tissue injury only, he states: 
“I disagree. This lady had minimal if any symptoms in the right knee at that time. She clearly has had knee pathology in that right knee because she has had a total knee replacement on the left hand side and it is most unusual for this to occur spontaneously on the left leg only.”
14.	Dr Bodel also disagrees with the opinion of Dr Sekel. He provides the following diagnosis: 
“The diagnosis here is twisting injury to the right knee or the aggravation, acceleration, exacerbation and deterioration to the disease process which is the degenerative arthritic change in that knee which predated the injury but was relatively asymptomatic and aggravated, accelerated, exacerbated and deteriorated by that event at work.”
15.	He opines that injury occurred as a result of work, that employment is the main contributing factor to that injury, and also that:
“It is also the main contributing factor by way of aggravation, acceleration, exacerbation and deterioration of a disease process being the arthritic change in that right knee which had been asymptomatic or relatively so prior to the injury.”
16.	He accepts that the need for surgery is causally related to the injury that occurred at work, noting that Ms Casey had completed similar work for at least seven years prior to the date of injury with the respondent and 23 years in total “without any problems with the right knee”. 
Reports of Dr Machart
17.	Dr Machart provides a report as an independent medical expert for the respondent. The history he takes of problems in the right knee slightly differs to that of Dr Bodel. He records that the right knee was assessed as “bone-on-bone osteoarthritis prior to the injury”, and was suffering from pain for about two years prior to the injury, involving X-rays, and treatment with various medications. The diagnosis is: 
“Soft tissue injury to the right knee on 16/06/2022, on the background of bone-on-bone osteoarthritis before the injury. I did not see evidence of additional structural injury caused by the incident on 16/06/2022. The soft tissue injury was manifestation of existing osteoarthritis. The osteoarthritis has prognostic features of gradual deterioration over time, and eventually reaching the stage where knee replacement is required. I do not have evidence that the soft tissue injury on 16/06/2022 accelerated the natural progression of osteoarthritis”
18.	Dr Machart considers that employment with Hammondcare was the main or substantial contributing factor to “the minor soft tissue injury yes, and not the current diagnosis of bone-on-bone OA”. 
Reports of Dr Sekel
19.	Dr Sekel provides two reports as an injury management consultant. It is noted that he did not see the applicant but reviewed the documents only. The applicant objected to the inclusion of the reports in the material, or in the alternative that I give the report no weight. I will deal with that submission below. In determining that submission, I have given close consideration to the substance of the report.  
20.	In his report dated 5 December 2022 Dr Sekel takes issue with the mechanism of injury, suggesting that the description of how the injury occurred would at most cause only a minor strain. Dr Sekel then suggests that the incident may have caused a temporary exacerbation of a pre-existing condition, referring to clinical records that show “significant pain in that same knee prior to the incident”. 
21.	Dr Sekel records a series of dot points said to be relevant to the injury management consultation: 
(a)	Ms Casey has significant disability in her right knee, as was indicated by the X‑ray of March 2022; 
(b)	she will remain permanently unsuitable to undertake some of the heavier tasks of a community work; 
(c)	any soft-tissue injury or strain would have returned to its pre-existing condition within a few minutes, hours, or a most weeks; 
(d)	beyond that point ongoing disability is not related to the incident that occurred, and
(e)	any certificates concerning reduced work capacity should be written on a private certificate format, not a certificate of capacity. 
22.	Dr Sekel also provides a stage 2 injury management consultation report dated 23 March 2023. This was also conducted on a review of the documentation alone. That report commences by referring to the previous report discussed above. Dr Sekel makes a suggestion that the applicant or applicant’s treating doctor (who at this time was Dr Nikolova-Trask) had failed to report the previous history of symptoms in the right knee. Dr Sekel apparently made a significant number of attempts to contact Dr Nikolova-Trask to recommend to her that all further medical certificates should not be deemed as work related. 
Report of Dr Clarnette
23.	Dr Clarnette is an orthopaedic surgeon who treated Ms Casey on referral from Dr Nikolova-Trask. He records the incident whereby the applicant was “supporting the client with her right knee”, and that there was no collapse or incident at the time but two days later it was sore and swollen. Dr Clarnette considered the previous history in the knee and states: 
“Prior to that she had no history of injury or surgery, she did have some minor aches in the knee but did not have much in the way of night pain or swelling.” 
24.	Under the heading of “impression” the following is recorded: “I have told Lee-Anne that I do not think it is surprising that Workcover are rejecting her claim since she had pre-existing arthritis and the injury was really negligible”.  

Clinical records and imaging
25.	As set out above, there is a significant volume of clinical records filed, largely under the cover of the two Applications to Admit Late Documents. I will refer to those records the parties took me to during the course of my reasons below. Included in those clinical records is an extensive history of radiology undertaken by the applicant. I will refer to those reports where relevant. 
SUBMISSIONS
26.	The parties provided oral submissions at the hearing. Ms Campbell of counsel appeared for the applicant, whilst Mr Stiles of counsel appeared for the respondent. As those submissions are recorded, I do not intend to repeat them in full but provide a brief summary here. 
Applicant’s submissions
27.	The applicant commenced by acknowledging the pre-existing issues with the right knee. The applicant submits that the injury was an aggravation of a pre-existing disease, which is accepted by the respondent. The applicant’s case is that the aggravation continues, but the insurer’s case is that the aggravation has ceased. 
28.	The applicant then turned to the reports of Dr Sekel, submitting that they significantly impacted how the matter progressed, equating it more akin to a s 78 notice than an independent medical expert report. The primary position of the applicant is that Dr Sekel’s  reports should be totally rejected, with a backup submission that I give them no weight. It is submitted that Dr Sekel has breached Procedural Direction PIC4 – Expert Witness Evidence, and the reports contain errors in history and tarnished the applicant’s credit. Alternatively, it was submitted that Dr Sekel has explained how he came to the conclusions he reached. 
29.	The applicant referred to the relevant law concerning consideration of disease and main contributing factor, with reference to Taylor v J & D Stephens Pty Ltd [2018] NSWCA 287 (Taylor) and AV v AW [2020] NSWWCCPD 9. It was submitted that it is necessary that employment is the main contributing factor to the aggravation, not the underlying disease process as a whole. Dr Bodel properly grapples with the pre-existing injury and aggravation from the incident. He does not say that she was asymptomatic and was in fact aware of the prior symptoms, he uses the word “relatively so”. She had some pain, but was relatively asymptomatic. 
30.	The applicant submits that the report of Dr Bodel should be preferred to that of Dr Machart. Dr Machart agrees that she suffered an injury on that day but suggests that she should have recovered. 

Respondent in reply
31.	The respondent submits that the starting point of the exercise is to go back and look at the history in relation to the right knee. The respondent submits that this goes as far back as 2008, referring to an X-ray which led to a right knee arthroscopy. From this point on there is a history of the applicant going back to Dr Crowley and continuing investigations of both knees. The respondent also went through the related clinical notes that record issues with the knee, including up until the investigations that occurred three months prior to the work injury. 
32.	The respondent referred to the report of Dr Clarnette, the applicant’s treating specialist. Whilst the report confirms the previous history with the left knee replacement, it records no history of injury or surgery to the right knee which is not accurate – the applicant had a clear history of injury and prior surgery, there were numerous investigations littered throughout the clinical material and doctors had been monitoring and investigating the condition for many years. 
33.	The respondent made the same criticism concerning the report of Dr Bodel – that is that he doesn’t take any of the history of past knee problems. He sort of acknowledged some past symptoms but doesn’t refer to the fact that she’s had an arthroscopy, or and doesn’t refer to any of the previous scans or X-rays. On that basis it was suggested that Dr Bodel’s opinion could not be said to have been made in a fair climate as he did not take an adequate and complete history. On this basis it was suggest that the opinion of Dr Bodel could be given little or no weight. 
34.	The respondent referred to the applicant’s statement suggesting there were some inconsistencies contained therein. In particular, the statement (at [9]) records that Ms Casey was fit and healthy prior to her subject employment, but that does not accord with the other material provided. 
35.	The respondent then turned to the report of Dr Sekel, which the applicant made submissions about. The respondent submits that the comments of Dr Sekel are consistent with the history and background concerning the work injury. The respondent submitted that much of the submissions don’t take the matter anywhere, and that Dr Sekel did not take an incorrect date of injury, but there was confusion about the date that the applicant first saw Dr Nikolova-Trask. The respondent suggests that it is not a fair criticism of the opinion of Dr Sekel. His opinion is that the soft tissue incident would have returned to the pre-injury condition, which I should accept because the medical evidence before me indicates that that is the case. 
36.	The respondent submits that Dr Machart has taken the history, and that there is no evidence that the incident that occurred had any impact on Ms Casey’s osteoarthritis. That is the view that I ought to accept, as it’s something that’s been there for many years. 
37.	In those circumstances, it is submitted that the need for surgery does not result from any soft tissue injury, but rather to deal with the degenerative condition. The respondent submits, with reference to Murphy v Allity Management Services Pty Ltd [2015] NSWWCCPD 49, that there has been no material contribution from the subject incident. The respondent also referred to Usher v Coffs Harbour City Council [2022] NSWPICPD 9. 
Applicant in reply
38.	In reply, the applicant accepted the respondent’s submission about the date issue, that Dr Sekel was simply reporting what he saw in another document. 
39.	The applicant submits that one thing that was missing from the examination of the history in this case, is that the applicant was working with all the problems all through until the injury that occurred. This injury was the final straw. 
40.	It was said to be not surprising that the applicant did not mention something that occurred in 2008 (being the earlier arthroscopy). There’s been a long chain, a complex history, but the incident at work changed things. 
FINDINGS AND REASONS 
41.	There is no dispute factually that in this case, an incident occurred on 15 June 2022 that caused a problem in the applicant’s knee. There are competing constructions of the exact mechanism of how that injury occurred. I accept the history as recorded in the applicant’s statement, whereby the patient she was assisting landed directly on the knee. That is, I do not accept the assertion made by Dr Sekel that the applicant merely straightened her knee. 
42.	The injury as conceptualised consistent with the workers compensation legislation varies between the parties. The applicant pleads injury in the following terms: 
“The Applicant suffered an aggravation, acceleration, exacerbation and deterioration of an underlying disease process, being previously asymptomatic osteoarthritis in the right knee, as a result of a workplace accident which occurred 15 June 2022.”
43.	The applicant goes on to explain the mechanism of injury:
“At the time, the Applicant was working as a Community Care Worker with HammondCare. She had worked for the insured since 2017, and had worked in disability support for 23-years. On the subject date of injury, the Applicant was attending to a client at her home. As she was assisting her in the bathroom, her client suffered an transient ischaemic attack, lost balance and started to fall. The Applicant grabbed her and strained against her weight to prevent her from falling. This resulted in her suffering a severe twisting injury to her right knee. She subsequently attended the ED where imaging of her knee was taken, and swelling over the knee was observed. She later consulted her treating doctor and was certified with nil capacity for work and referred for an MRI.” 
44.	In their s 78 notice dated 19 July 2023, the respondent disputes that the injury occurred in the nature of an aggravation of a disease, but accepts that the applicant suffered a soft tissue injury: 
“As such, based on the above outlined information, Allianz accepts that you sustained a soft tissue injury to your right knee, in the course of your employment with Hammondcare, however we do not accept that you suffer from compensable injuries in the context of bone on bone osteoarthritis to the right knee and therefore do not agree
that those injuries arose out of or in the course of employment as required by section 4 of the Workers Compensation Act 1987.”
45.	The respondent also asserts that the accepted soft tissue injury has resolved: 
“In respect to the soft tissue injury to the right knee, based on the report of Dr Frank Machart outlining your injury has resolved, it follows that we also do not agree that you are entitled to ongoing weekly benefits or medical or related treatment for this injury pursuant to section 33 and section 59 and 60 of the Workers Compensation Act 1987.”
46.	The position of the respondent is somewhat confused by the review request dated 7 May 2024. That notice states: 
“Although the evidence appears to support that you suffered an aggravation or exacerbation of your degenerative right knee condition as a result of the injury, the evidence also suggests that any such aggravation was temporary and resolved; and that any continuing symptoms, restriction and need for treatment are solely attributable to your pre-existing osteoarthritis.”
47.	The applicant commenced submissions by referring to the aggravation of a disease, suggesting that the respondent had accepted that the applicant’s pre-existing disease had been aggravated, but that any such aggravation had ceased. The above part of the s 78 notice seems consistent with that position, but inconsistent with the summary of the decision, which puts into issue “arising out of” and “in the course of” employment pursuant to s 4, as well as “main contributing factor” pursuant to s 4(b). 
48.	Given the applicant has presented their case as an aggravation of a disease, and there is no dispute about the occurrence of a soft tissue injury (although there may be a dispute about whether that soft tissue injury has resolved) I will deal with that issue. If the applicant is successful, I will also consider whether the need for surgery (which is consistently accepted as being reasonably necessary) arises as a result of the injury, or due to another cause. 

The report of Dr Sekel
49.	As the applicant commenced submissions by attacking the report of Dr Sekel, I will determine that issue first. The applicant submits that the report should either not be admitted, or given little to no weight. 
50.	The applicant referred and relied on PD PIC4. No specific references were made to parts of the PD, but relevant are the overriding duties to the Commission:
“7.    A party proposing to call a witness to give evidence as an expert has a duty to ensure the witness is aware of the requirements of this Procedural Direction.
8.    An expert witness has an overriding duty to assist the Commission impartially on the real issues in dispute relevant to the expert's area of expertise.
9.    An expert witness's paramount duty is to the Commission. An expert witness is not an advocate for a party or the person retaining them.
10.  In accordance with rule 35(3), evidence that does not comply with this Procedural Direction is not admissible in the Commission unless the Commission orders differently.”
51.	Dr Sekel, at the commencement of his report, refers to the Uniform Civil Procedure Rules (which are not applicable here) and PD PIC 4. Reading of and agreement to be bound by the relevant procedural direction does not mean that the evidence will comply with that procedural direction. It is noted that Dr Sekel’s report is in the guise of an injury management consultation. It was based on a review of the documents alone. 
52.	An injury management consult (IMC) occupies a different space withing the legislative scheme to that of an independent medical expert. The legislative basis for the existence and appointment an IMC is set out in s 45A of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act). Sub-section (4) refers to the Workers Compensation Guidelines (Guidelines) providing functions of “approved injury management consultants”. No issue was taken with Dr Sekel’s appointment as an approved injury management consultant. 
53.	Part 6 of the Guidelines is issued in accordance with s 45A(4). It provides for the role and purpose of an IMC: 
“An IMC is a registered medical practitioner experienced in occupational injury and workplace-based rehabilitation.
An IMC is a facilitator who helps the nominated treating doctor, worker, insurer, employer and other service providers to progress a worker's recovery at/return to work and optimise health and work outcomes. An IMC assesses the situation, examines the worker (if necessary) and discusses possible solutions with the relevant parties. The IMC mediates with parties to seek agreement on actions and outcomes. IMCs are not responsible for directing treatment of a worker, though they may comment on treatment in respect to overcoming barriers to recovery at/return to work.
An IMC may conduct a file review where a referrer identifies the need for an injury management consultation but does not consider it necessary for the IMC to examine the worker.
An IMCs functions do not include:
•	an opinion on causation or liability
•	undertaking a functional capacity evaluation, or work capacity assessment (as defined in section 44A of the 1987 Act) for the insurer.”
54.	Part 6.6 for the completion of an IMC report, including where the report is to be forwarded and what the report is to include (at a minimum). 
55.	In my view, in his report Dr Sekel steps far outside of the scope of an IMC. On page 1 of the report, Dr Sekel questions the mechanism of injury, suggesting that it would only cause a minor strain. He then goes on to question the report of ongoing pain. He reports the pre-existing history of knee pain (which I accept may be a relevant part of the role of an IMC, for the purpose of determining a return to work plan). 
56.	On page 2 of the report, Dr Sekel again raises doubts about the mechanism of injury:
“As stated above, that description suggests that Ms Casey did not press her knee into the client’s body, but merely straightened (‘braced’) her knee, pushing against the ground with her foot, which could only cause a minor strain. Even if she had press her knee into the client’s body, this would only cause (at most) a temporary strain, especially as she already had ‘bone on bone’ requiring an x-ray of that knee only 3 months earlier.” (emphasis in original) 
57.	I accept that an IMC is not required to examine the worker (as did not occur in this case). However, given the apparent doubt as to the mechanism of injury, it may have been of assistance. 
58.	Dr Sekel then appears to take issue with Ms Casey seeing Dr Nikolova-Trask, as opposed to Dr Wenham, who she had previously seen for an X-ray. Dr Sekel provides a conclusion, pointing out “the following is relevant regarding today’s Injury Management Consultation”. Dr Sekel relevantly records: 
“Any soft tissue injury or strain of the right knee that might have occurred on 15 or 16/6/22 would have completely return to its pre-existing condition within the initial few minutes, hours or at most a few weeks.
Beyond that period, Ms Casey’s ongoing disability is not related to the claimed incident on approximately 16/6/22, and is not related to the nature and conditions of her employment.” 
59.	This is a clear and strong opinion provided as to causation. Pursuant to the Guidelines, this is outside of the functions of an IMC. There is also no discussion of the worker’s recovery at/or return to work, or to optimise health and work outcomes. Although there are some notations that Dr Sekel agrees with Ms Casey’s assertion that she will not return to pre-injury duties, there is no suggestion of what other tasks may be suitable to allow Ms Casey to recover at work, or to overcome barriers to return to work. 
60.	Finally Dr Sekel provides: 
“As such, if her general practitioner provides her with ongoing certificates (including perhaps a permanent Final certificate) indicating reduced work capacity,  I recommend that this should be written on a Private certificate format, not a SIRA certificate of capacity.” (emphasis in original)
61.	Dr Sekel apparently communicated the above to Dr Wenham (rather than Dr Nikolova-Trask), “who agreed with all of the above… he agreed that any further certification will be written on a private certificate, not a SIRA certificate of capacity”. 
62.	Dr Sekel’s second report, dated 23 March 2023, follows much the same line of reasoning. Dr Sekel is critical of the initial certificate of Dr Nikolova-Trask, which failed to record the pre-existing issues with the right knee. This updated report seems to have been triggered by Dr Nikolova-Trask’s failure to comply with his recommendation that all further certificates be provided on a private certificate.
63.	Apparently Dr Sekel attempted to contact Dr Nikolova-Trask on at least 15 occasions but was unable to do so and she has not returned any calls. Dr Sekel concludes that “all further medical certificates should be on a Private Certificate, and not be deemed as work-related”. This takes the earlier conclusion in relation to the SIRA certificate of capacity a step further, suggesting that the worker’s treating doctor should no longer deem the injury to be work related. 
64.	Again, this is an obvious conclusion as to causation. There is no attempt to provide any return to work pathway for Ms Casey. It is also noted that both reports were provided to the insurer and the nominated treating doctor (Dr Nikolova-Trask) but not to Ms Casey, in breach of part 6.6 of the Guidelines. I have based this conclusion on the “cc:” field at the end of both reports. There is no explanation as to why the report was not provided to Ms Casey, or a suggestion that the release of the report would pose a serious threat to the life or health of the worker or any other person. 
65.	The above leads me to the conclusion that Dr Sekel was not acting in his capacity as an IMC when providing both reports relied upon by the respondent. The applicant submits that Dr Sekel was acting as an advocate for the insurer. If the report had been prepared as an independent medical expert opinion, I may not have accepted that submission. It is within the scope of an IME to comment on causation. However, the report was prepared in the context of an IMC assessment and must accordingly be considered as such. 
66.	I accept the applicant’s submission that Dr Sekel was acting as an advocate for the insurer in the conduct of the dispute. He encouraged the applicant’s treating doctor to stop issuing certificates of capacity and to conclude that Ms Casey had not deem the injury to be work related. As the evidence does not comply with the Procedural Direction, it is not admissible in the Commission, in accordance with [10] of PD PIC4. 
67.	However, given that clause refers to r 35(3) of the Personal Injury Commission Rules 2021, which concerns the calling of a witness to give evidence, it may be that clause of the Procedural Direction is directed only to circumstances where oral evidence is sought to be adduced from an expert. In the alternative, for the reasons above I am not satisfied that the report was validly produced within the functions of an IMC, and accordingly give it no weight. 
Injury and main contributing factor
68.	The critical issue in these proceedings is whether the applicant suffered an injury, being the aggravation of a disease, to which employment was the main contributing factor. The parties agree that the relevant test is that as set out in AV v AW. In that case, DP Snell considered the test at length, from [65]-[78]. The summary provided at [78] reflects the present position of the law: 
“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.”
69.	The applicant referred to the decision of Taylor in which the court explained the three components of a disease injury: 
“It can be seen that there are three components to a ‘disease injury’ – the existence of a ‘disease’, that the disease was contracted (or aggravated etc) in the course of employment, and that the employment was the main contributing factor to the contraction (or aggravation etc) of the disease. If all three are demonstrated, the worker has suffered a ‘disease injury’ within the meaning of s 4(b), and is entitled to benefits as prescribed by Part 3 of the WC Act.” (at [33])
70.	There are a number of factors that are apparent on the evidence before me relevant to the question for determination. It is clear that Ms Casey had a previous history of knee problems dating back to at least 2008. This include issues in the left knee (not claimed to be work related) which eventually led to a knee reconstruction. In the right knee, the issue in dispute, there was evidence of significant pathology radiologically including in the period shortly before the work injury. 
71.	It is also clear that Ms Casey was functioning in a reasonably normal manner until the work injury. She was performing what, at times, must be considered heavy work, assisting people and completing heavy domestic tasks. Dr Bodel records that the knee was “previously relatively asymptomatic”, which probably accords with the true picture of Ms Casey prior to her work injury. There was no suggestion that the statement of the applicant was not accurate or her history of functioning could not be accepted. 
72.	On the other hand there is the significant history of attendances on doctors due to problems in her right knee. These attendances were mostly with Dr Crowley, and the respondent during submissions took me to those records, which appear variously throughout the late documents filed. The relevant records prior to the date of injury are as follows: 
(a)	6 February 2008 - A weight bearing view of the right knee, referred by Dr Crowley, with a clinical history of a meniscal tear for a pre-op assessment.
(b)	22 May 2008 – a post-surgery report by Dr Crowley, who performed a right knee arthroscopy.
(c)	21 June 2011 – an X-ray of both knees, with a history of “suspected osteoarthritis”, with a commentary of “the appearances indicate established bony changes of osteoarthritis with early joint compartment narrowing”.
(d)	7 May 2012 – an X-ray of the right knee, with a clinical note of “PFJ pain suggesting OA” with a conclusion of “findings consistent with incipient OA but not unusual for the patients age”.
(e)	11 August 2015 – an X-ray of both knees with clinical information of “Left knee OA for assessment”, recording “patellofemoral OA is seen. There is no acute bone injury. No evidence of a joint effusion”.
(f)	26 July 2016 – an X-ray of both knees, with clinical details “? OA.”, reporting “Joint space loss medial compartment of the left knee, more prominent when compared to the right hand side”. It appears that the remainder of the report concerns the left knee, or it is not clear.
(g)	23 April 2019 – an X-ray of both knees, with clinical history of “Had replacement, complains of clicking and some pain, review”. This is clearly following the left knee replacement, but both knees were examined. In relation to the right knee, it is recorded “There is moderate loss of joint space in the medial and lateral compartments. There is generalised reduction in bone density”.
(h)	9 April 2021 – an X-ray of the right knee, tibula and fibula. There is no clinical note or history. There is a triage note of the same date, recording “pt presents following fall 5/6 ago onto right knee and hand”. The knee report records “Small effusion. Osteophytes all three joint compartments. Moderate joint space loss medial lateral compartment. Joint space loss more marked laterally. No fracture identified”.
(i)	16 March 2022 – clinical note from Dr Wenham noting “pain in right knee, swelling sometimes, radiates. TKR 3 yrs ago LHS”. This resulted in a referral for medical imaging.
(j)	21 March 2022 – report from an X-ray that took place on 17 March 2022. The findings are “Joint space narrowing is seen at the lateral compartment in association with minor genu valgum deformity. Mild to moderate spiking of the tibial spines is evident. Slight marginal lipping is seen peripherally in the lateral compartment on the tibial side. The patella is enlocated. Mild marginal lipping is demonstrated superiorly and inferiorly at the patella. A small amount of fluid is noted in the suprapatellar bursa. No loose bodies can be identified”.
(k)	19 April 2022 – clinical note from Dr Wenham noting “needed convincing of R xray rather than L. Fell down on it shortly afterwards and ache in upper tibial area”. 
73.	The applicant made submissions addressing the pre-injury issues with the knee, in particular the entry dated 19 April 2022. The applicant submits that it can be inferred that she needed to be convinced of an X-ray because she did not think that it was a real problem. I do not think that can be reasonably inferred from the evidence. Even if that were the case, it does not change the fact that there are extensive records of attendances due to issues in the right knee, as set out above. It does not change the weight that can be given to that long history. 
74.	The work incident occurred on 15 June 2022. The applicant presented to the emergency department on 17 June 2022, and the following is recorded: 
“workplace injury
employed as a carer in the community 
attending a client on Wednesday 
steadied the client to stop them from falling, causing strain to lower back and R knee did not fall 
known osteoarthritis, R knee ‘bone on bone’ 
takes regular anti-inflammatory and paracetamol for same”
75.	Ms Casey first attends Dr Wenham following the incident at work on 21 June 2022. He records “One week since had to hold patient prior to chair coming. Soreness R knee, worse overnight. Also swelling. Hospital doctor said MRI”. Dr Wenham describes it as a “loading injury”. 
76.	On 29 June 2022, Ms Casey begins seeing Dr Nikolova-Trask in relation to the work injury. From that date, there are ongoing and continuing reports of pain and stiffness in the right knee. This includes a record on 17 July 2023 of the right knee giving way while working. 
77.	On 29 May 2023, Ms Casey sees Dr Nikolova-Trask. The report of Dr Sekel is referred to in the clinical note. Dr Nikolova-Trask notes, in relation to the report that he had “never actually seen, examined or even spoken to Lee”. A referral to Dr Clarnette was prepared. 
78.	Dr Clarnette provides a report back, dated 19 September 2023. This records a history of left total knee replacement and notes “the right knee is the problem at this stage”. The history recorded is that “she had no history of injury or surgery, she did have some minor aches in the knee but did not have much in the way of night pain or swelling”. He gives an impression that it is not surprising that her workers compensation claim had been rejected “since she had pre-existing arthritis and the injury was really negligible”. 
79.	Arising out of this analysis of the clinical history of Ms Casey’s right knee are some relevant factors for the consideration of the test set out in AV v AW and Taylor:
(a)	the disease in this case is osteoarthritis; 
(b)	there was an incident at work that impacted on the applicant’s right knee, and 
(c)	there are work and non-work related causal factors. The work related factor is the incident on 17 June 2022, whereby a patient fell, causing the applicant to place her knee out to prop up the patient, resulting in the patient falling on the knee. The non work-related factors are the significant history of knee pain resulting in numerous attendances and radiological investigations, dating back to 2008. 
80.	In order to succeed, the applicant must prove, on the balance of probabilities, that the incident on 15 June 2022 aggravated (etc) her underlying osteoarthritis, and that employment was the main contributing factor to that aggravation (etc). 
81.	There are competing medicolegal opinions in relation to this causation question. Dr Bodel provides an opinion in support of the applicant. Dr Machart does not. 
82.	There are, in my view, some relevant flaws in both medicolegal opinions. Dr Bodel does not record a significant history of previous knee problems. In my view this is inconsistent with the 14-plus year history recorded in the clinical notes of repeat attendances for knee problems and multiple radiological investigations. It is acknowledged that some of the attendances that led to radiology arose out of the applicant’s left knee issues, which was subject of a total knee reconstruction outside of the workers compensation system. However, the radiology, as I have summarised above, shows ongoing and consistent problems with the right knee. None of that history is considered by Dr Bodel. In fact, he records that “there were no x-rays or other tests available for review today”. This in spite of the long history of radiology that existed, and would have been relevant for the consideration of Dr Bodel. 
83.	Dr Bodel also records that Ms Casey had “minimal if any symptoms in the right knee at that time”. Again, this is inconsistent with the lengthy history of right knee radiology and attendance on 16 March 2022 which recorded knee pain. It may have been that on the date of the work incident Ms Casey did not have significant symptoms, but it is difficult to ignore the complaints only three months prior to that incident. Dr Bodel goes on to record that: 
“She clearly has had knee pathology in that right knee because she has had a total knee replacement on the left hand side and it is most unusual for this to occur spontaneously on the left leg only.”
84.	Here, Dr Bodel has based his conclusion of knee pathology on a hypothesis arising out of the previous left knee replacement, rather than on the actual facts of the matter that show the knee pathology through clinical records and radiology. I have difficulty accepting the applicant’s submission that he properly grapples with the issue of the pre-existing injury as he has not taken a proper history. 
85.	Likewise the X-ray of 9 April 2021 is important to the opinion of Dr Bodel. He discusses the opinion of Dr Machart which refers to “bone on bone osteoarthritis”. He states “Maybe she has in the retropatellar region but it is not in the main body of the joint itself”. However, the X-ray of 9 April 2021, which predates the injury by more than a year, shows osteophytes in all three joint compartments, with joint space loss more marked laterally. In response to specific questions, Dr Bodel records under “history”: 
“This lady has suffered a twisting injury to the right knee and this occurred in the manner described above.
She had previously asymptomatic degenerative change in that knee and that event has caused aggravation, acceleration, exacerbation and deterioration to that disease process.”
86.	The conclusion that the applicant suffered “asymptomatic degenerative change” is inconsistent with all of the other evidence, particularly the clinical notes and radiology referred to above. It is noted that under diagnosis Dr Bodel does step back slightly from that conclusion by describing the injury as “relatively asymptomatic”, but it is not explained what is meant by “relatively” or what it is relative to. 
87.	These factors suggest that Dr Bodel’s opinion may not have been made in a “fair climate” per Paric v John Holland (Constructions) Pty Ltd [1984] 2 NSWLR 505 at 509-510; Paric v John Holland (Constructions) Pty Ltd [1985] HCA 58; (1985) 62 ALR 85). This brings into question the weight that I can give that evidence; Onesteel Reinforcing Pty Ltd v Sutton [2012] NSWCA 282. 
88.	The applicant finds little support in the treating specialist. Dr Clarnette is unsurprised that the workers compensation claim was rejected describing the incident as “really negligible”. 
89.	On the other hand, and as pointed out by the applicant in submissions, is the fact that in spite of the above lengthy history of attendances and investigations, Ms Casey continued to work in quite heavy work, with the respondent for seven years and in the care industry in general for 23 years. There has been a long causal chain and the incident at work changed things fundamentally. The history following the work incident is one of continuing pain and disability. I accept that there was a fundamental change in the applicant’s presentation after 15 June 2022. 
90.	I have rejected the opinion of Dr Sekel as being outside of the scope of an IMC and accordingly will not consider it, or give it any weight. 
91.	That leaves the competing report of Dr Machart, relied on by the respondent. He records that the right knee was assessed as bone-on-bone osteoarthritis prior to the injury, and was suffering from pain for about two years prior. Again, he does have before him any of the significant history of X-rays prior to the work injury. It may be because that material was only made available following the direction for production process at the Commission. He refers to the MRI dated 11 July 2022 which is taken after the incident. 
92.	Dr Machart’s opinion is that the applicant suffered a soft tissue injury. His conclusion is that “bone-on-bone osteoarthritis responsible for the symptoms before and after the incident”. In terms of the symptoms being worse, he states “this narrative is consistent with the natural progression of bone-on-bone osteoarthritis. Symptoms do get worse, and eventually there is a need for knee replacement”. 
93.	It is not clear where the “bone-on-bone osteoarthritis” arises from. That is not recorded in any of the radiology and Dr Bodel does not agree with that conclusion, although he has not reviewed any of the relevant material. In the discharge summary of 17 June 2022 it is recorded “known osteoarthritis, R knee ‘bone on bone’”. It may be that the history of “bone-on-bone osteoarthritis” is the applicant repeating what she has heard. I cannot be certain. I am of the view that Dr Machart has taken a history closer to the reality of the situation than that of Dr Bodel. Osteoarthritis is first reported with joint space narrowing on 21 June 2011. Joint space loss is reported again on 26 July 2016, but noted to be worse in the left knee. By 9 April 2019, osteophytes are present in all three compartments, with moderate joint space loss medially and laterally, with marked loss laterally. On 23 April 2019, joint space loss is described as “moderate” in the medial and lateral compartments.  On 21 March 2022, joint space narrowing is seen in the lateral compartment. 
94.	Thus a consistent history of joint space narrowing is recorded from 21 June 2011. I accept Dr Machart’s medical opinion that by the time of the incident on 15 June 2022, the applicant was suffering from bone-on-bone osteoarthritis. The applicant was coping with the clinical position she found herself in, and was able to work until 15 June 2022. That does not mean that she was asymptomatic, or relatively so. That conclusion is unsupported in the clinical records. 
95.	Considering all of the above factors, including the reduced weight I can give to the report of Dr Bodel on account of his failure to take a proper history of the pre-existing and significant issues with the applicant’s knee, I find that I am unable to accept that the applicant has proved, on the balance of probabilities, that on 15 June 2022 she aggravated her pre-existing osteoarthritis. 
96.	In the words of Dr Clarnette, the injury on that date was “really negligible”, being a soft tissue injury. The presentation of the worker since that date is due to her underlying osteoarthritis. 
97.	Even if I were satisfied that the applicant aggravated her underlying osteoarthritis on 15 June 2022, I would not be satisfied that employment was the main contributing factor to that aggravation. The clinical picture of the applicant prior to that date was so dire that the only conclusion available, as set out by Dr Machart, is that bone-on-bone arthritis is responsible for the symptoms before and after the incident. 
98.	Further, if it is the case that the respondent has accepted the applicant suffered an injury, being an aggravation of a disease and all of the appropriate questions that go with that including main contributing factor, for the reasons above I accept the respondent’s submissions, based on the report of Dr Machart, that any such aggravation has ceased. 
99.	Accordingly, I will make an award for the respondent.