Walsh v Balranald Shire Council

CERTIFICATE OF DETERMINATION OF MEMBER
CITATION:	Walsh v Balranald Shire Council [2021] NSWPIC 383
APPLICANT:	Anne Walsh
RESPONDENT:	Balranald Shire Council
MEMBER:	Catherine McDonald
DATE OF DECISION:	29 September 2021
CATCHWORDS:	WORKERS COMPENSATION - Worker suffered an accepted injury to her back for which she underwent surgery; ceased work as a result of a subsequent psychological injury; claim that she suffered injury to her knees as a result of the nature and conditions of her employment or in the alternative that she suffered a consequential condition as a result of altered gait or weight gain; Kooragang Cement v Bates, Bouchmouni v Western Red Cedar and Nguyen v Cosmopolitan Homes discussed; Held – claim for further permanent impairment of back remitted for referral to a Medical Assessor; award for the respondent with respect to left and right knees.
DETERMINATIONS MADE:	1. Award for the respondent on the claim that the applicant suffered a consequential condition in her left and right knees. 2. I remit the matter for referral to a Medical Assessor to assess the applicant’s permanent impairment as a result of an injury to her lumbar spine on 23 March 2009. 3. Note that a face to face examination will be necessary. 4. I direct that the parties prepare an agreed bundle of documents for the Medical Assessor within 21 days.

STATEMENT OF REASONS

BACKGROUND

Anne Walsh was employed by Balranald Shire Council (the Council) as a personal care assistant (PCA) at the Bidgee Haven Aged Care Hostel. Ms Walsh had concurrent employment with MacKillop Rural Community Services as a carer for people in their homes. Her concurrent employment is not relevant to the issues to be determined in these proceedings.
On 23 March 2009, Ms Walsh suffered an injury to her back when she tried to prevent a patient from falling. She underwent surgery on 2 August 2011 for which the Council accepted liability. In April 2012 Ms Walsh was compensated for 14% whole person impairment (WPI) as a result of the back injury. She received compensation under s 67.

Ms Walsh ceased work with the Council in May 2012 as a result of a psychological injury. The Council disputed liability for compensation on the basis of s 11A of the Workers Compensation Act 1987 (the 1987 Act), alleging that it took reasonable disciplinary action because Ms Walsh had performed duties inconsistent with a return to work plan. An arbitrator of the former Workers Compensation Commission made an award for weekly benefits and s 60 expenses in favour of Ms Walsh, which was confirmed on appeal.[1]
[1] [2013] NSWWCCPD 47.
Ms Walsh claims further permanent impairment compensation in respect of her lumbar spine. The Council does not object to an assessment of her impairment by a Medical Assessor.
Ms Walsh also claims compensation in respect of injury to her right and left knees as a result of the nature and conditions of her employment with the Council after 23 March 2009 and in respect of a consequential condition. She has undergone bilateral total knee replacement surgery.
The consequential condition is said to have arisen because Ms Wash gained increased weight after her back surgery which aggravated arthritis in her right knee. That aggravation required total knee replacement surgery which led to a further altered gait pattern, aggravating pre-existing arthritis in her left knee. In the alternative, Ms Walsh alleges that she suffered a consequential condition in both knees as a result of weight gain following her back surgery.
The issue for determination in these proceedings is whether Ms Walsh suffered an injury to, or suffers a consequential condition in, her right and left knees.

PROCEDURE BEFORE THE COMMISSION

The matter was listed for conciliation conference and arbitration hearing on 26 August 2021 when Mr Nicholson of counsel appeared for Ms Walsh and Mr Barter of counsel appeared for the Council. The hearing was conducted by video conference, though technical difficulties required Mr Nicholson to appear by telephone only.
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 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 had sufficient opportunity to explore settlement and that they were unable to reach an agreed resolution of the dispute.
The file is voluminous and the Application to Resolve a Dispute (ARD) is arranged in a somewhat confusing manner, with many documents appearing more than once. The parties agreed that, if I determined that Ms Walsh did not suffer injury to or a consequential condition in her knees, her claim for further compensation for permanent impairment of the back should be assessed by a Medical Assessor. In that case, they agreed that they would prepare a smaller agreed bundle of documents for the Medical Assessor.

EVIDENCE

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

(a)    ARD and attached documents;
(b)    Reply, and
(c)    Ms Walsh’s Application to Admit Late Documents (AALD) dated 9 August 2021.

There was no oral evidence.

The claim for permanent impairment compensation was made on 3 June 2020, supported by reports from Dr P Giblin dated 21 October 2019, 20 April 2020 and 12 May 2020. A further report from Dr Giblin is dated 3 November 2020.
The claim was denied in s 78 notices dated 13 October 2020 and 30 March 2021.

Because Mr Nicholson’s submissions were structured by reference to the contemporaneous medical evidence, I will summarise the evidence to which counsel referred me, below.
The attachments to the ARD are confusing because they are attached by reference to the dispute notices issued by the Council’s insurer rather than in chronological order. For that reason, I have used footnotes extensively.

SUBMISSIONS

Mr Nicholson

Ms Walsh’s general practitioner is Dr Slava Zotov but she has seen other doctors at the same practice since 1999. Mr Nicholson said that the first reference in the general practitioners’ notes was on 30 January 2002[2] when Dr Hemingway diagnosed a sprained lateral ligament of Ms Walsh’s right knee.
[2] ARD p 387.
On 11 November 2016[3], Dr Zotov referred Ms Walsh to Dr D James for severe mechanical right knee pain. The list of presenting problems in the standard referral letter included chondromalacia patella in 2003. The record for 20 February 2003[4] records that diagnosis.
[3] ARD p 286.
[4] ARD p 386.
Mr Nicholson said those were the only complaints in respect of Ms Walsh’s knees before the back injury in 2009. The general practitioners’ notes record that Dr Zotov requested a CT scan of Ms Walsh’s lumbar spine on 31 March 2009.[5] The scan, reported on by Dr D Arhanghelschi, showed a large left sided disc prolapse at L4/5 which obliterated the left lateral recess and compressed the left L5 nerve root, with associated mild to moderate canal stenosis.[6]
[5] ARD pp 384-5.
[6] ARD p 543.
Mr Nicholson said there were no relevant entries in the general practitioners’ notes until 9 March 2011. Ms Walsh was admitted to hospital on 9 March 2011, admitted from 9 to 11 March 2011 and treated for back pain.[7] She was admitted again from 12 to 17 May 2011.[8] Dr D Jeffries noted on 19 September 2011 that Ms Walsh had undergone disc removal surgery on 3 August.[9] Mr Nicholson noted that further radiology was undertaken in March 2012 and said that by 14 April, Ms Walsh had signed a complying agreement.
[7] ARD pp 505-506.
[8] ARD p 533.
[9] ARD p 380.
On 25 May 2012, Ms Walsh saw Dr Y Wang, neurosurgeon, after a repeat MRI scan. He said that her disc prolapse had been resected and there was no further neuro-compression. He noted that Ms Walsh was “continuing to work on a full-time basis albeit with lighter duties and this is entirely appropriate for her.” He said that she should not be involved in heavier work.[10] Dr Wang noted that Ms Walsh had some persisting pain symptoms.
[10] AALD p 8.

Mr Nicholson said that this indicated that Dr Wang was concerned about the impact of the work she did.
The general practitioners did not record any other complaints in respect of Ms Walsh’s knees until 29 January 2013 when Dr Zotov requested an x-ray of Ms Walsh’s left knee[11], which indicated that she had complained of pain. By 20 March 2013 Dr A Chai had undertaken a left knee arthroscopy, meniscectomy and chondroplasty.[12] The reason was set out in Dr Chia’s report dated 20 February 2013 to Dr Zotov.[13] He said:
“Anne has had right knee pain for over 2 months now. There was no history of recent injury, trauma or falls. She has noticed increasing right medial knee pain associated with clicking over the last 2 months. The pain is made worse with weight-bearing and walking. The pain has become very severe and Anne suffers from pain at night as well.
…
[11] ARD p 375.
[12] AALD p 4.
[13] AALD p 5.
I suspect that Anne has a medial meniscal tear in the background of mild medial compartment osteoarthritis. … She is aware of the risk of progressive osteoarthritis as this is already pre-existing.”
Mr Nicholson said that the history showed that Ms Walsh was not suffering any significant problem with her knees before her back injury. He took me to Dr Chia’s records which contain his report dated 4 April 2013. Dr Chia said that the arthroscopy revealed significant degenerative change and he recommended that Ms Walsh avoid high impact activities. He confirmed that degenerative arthritis was a progressive condition and that a total knee replacement may be required if she developed symptomatic arthritis.
Mr Nicholson then took me to Ms Walsh’s statements. In her statement dated 2 June 2021[14] she said that her knees started to become a serious problem because of 20kg weight gain and inactivity after her back surgery. She said that when she returned to work after that surgery she was doing all of her duties apart from mopping floors and showering patients and that the work was heavy. Those duties involved constant bending, stooping, kneeling, squatting and some fliting. She said that she relied more on bending her knees after the back injury in 2009 and after the back surgery in 2011.
[14] ARD p 1.
Ms Walsh said that she gained 20kg after the surgery. She noticed when she returned to work that her gait altered and that her knees became swollen and painful, the right before the left.
Ms Walsh also relied on a statement she provided to an investigator on 7 August 2012 in respect of her psychological injury.[15] She described her duties working in the hostel which accommodates 13 high and low care residents, involving showering, toileting, dressing, some feeding or assistance, grooming and personal hygiene.
[15] ARD p 23.
Mr Nicholson noted that Dr L Pierides prepared a report for the Council’s insurer on 1 May 2009[16], following her back injury. He was asked to assess whether Ms Walsh was capable of performing her normal duties. He noted that Ms Walsh was a little overweight for her height but that she was capable of standing on one leg with the opposite hip and knee flexed to 90 degrees without difficulty.
[16] ARD p 135
Returning to the chronology of events, Mr Nicholson said that after the surgery by Dr Chia and the claim in respect of the psychological injury, the focus returned to Ms Walsh’s back. On 15 October 2013 she told Dr Zotov that her back was still sore[17] and she made the same complaint on 23 June 2014[18] and 16 October 2014[19].
[17] ARD p 373.
[18] ARD p 371.
[19] ARD p 370.
On 31 July 2015 Dr Zotov recorded that Ms Walsh’s left knee was sore and swollen.[20] She was referred to Dr James who reported on 22 September 2015.[21] Dr James said that he saw Ms Walsh in respect of bilateral knee problems, noting that she had undergone arthroscopies on both. Her main concern was her left knee. He noted that she had a higher than average body mass index. He said that fresh radiology showed advanced degenerative change in the medial compartment of the left knee and similar changes in the right knee with “just moderate joint compartment narrowing in the medial femorotibial joint.” He said there were changes suggestive of degenerative wear in both patellofemoral joints. He referred her for a left knee MRI, anticipating that a total knee replacement would be required.
[20] ARD p 368.
[21] AALD p 3.
Dr James’ notes[22] confirm the matters set out in his report.
[22] From ARD p 273.
On 29 September 2016[23], Dr Zotov recorded that Ms Walsh’s right knee was restricted and swollen and he said he would refer her to Dr James again after an x-ray. On 11 October 2016[24] Dr Zotov noted that Ms Walsh had severe right knee pain and that she needed a walking stick. Her knee remained sore and Dr Zotov prescribed Endone on 17 October. Mr Nicholson said that on 6 December 2016[25] Dr Zotov noted that Ms Walsh had undergone a right knee arthroscopy “6/7”, that she had a sore and swollen right knee and was feeling sweaty and pale.
[23] ARD p 365.
[24] ARD p 365.
[25] ARD p 364
Mr Nicholson interpreted that reference as relating to surgery in July. I note however that Ms Walsh said in her statement that she underwent a right total knee replacement on 29 November 2016. Dr James’ operation report[26] said that the surgery was undertaken on 30 November 2019 so that the surgery six days (6/7) before was presumably that surgery and not an arthroscopy.
[26] ARD p 287.
Mr Nicholson noted that Ms Walsh’s right knee problems continued through 2017 and 2018.
On 27 March 2019[27] Dr Jeffries noted that Ms Walsh had lost 6 kg in the last three months. She had undergone one total knee replacement and was due soon for the other but wanted to put it off. The left total knee replacement was undertaken by Dr James on 31 May 2019.[28] He undertook a further arthroscopy on 10 July 2020[29], following which Ms Walsh suffered an infection in the wound.[30]
[27] ARD p 357.
[28] ARD p 318.
[29] ARD p 336
[30] ARD p 351.
Mr Nicholson noted that Dr P Giblin had undertaken assessments of permanent impairment before that surgery.[31]
[31] ARD p 66.
In support of the submission that the conditions in Ms Walsh’s knees were consequential on weight gain, Mr Nicholson took me to the references to an increase in weight in Ms Walsh’s statement and to Dr P Giblin’s report dated 21 October 2019[32] which he said was supportive of the clinical notes. Dr Giblin set out the history of Ms Walsh’s return to work in October 2011 “on light duties” until May 2012, after which she was off work for 18 months. In about 2013 she returned to her concurrent employment working two days per week with disabled adults, which she described as very light work. At the time of the consultation she remained in that work.
[32] ARD p 60.
Dr Giblin said in his first report:[33]
“In relation to the issues to her knees, it would be my opinion that the weight gain following the injury to her low back in 2009 is a material aggravating factor in relation to her preexisting right knee arthritis.
Her altered gait pattern in relation to the operation on the right knee and the limp in her left leg would also be a material consideration in terms of the acceleration of arthritis in the left knee.
It would be a reasonable clinical acknowledgement to note that there would have been a genetic component to the arthritis in both her knees being present prior to 2009. However, it remains my view that weight gain is a significant aggravating factor in terms of acceleration of the underlying genetic pre-disposition and that this aggravation would lead to surgical considerations such as total knee replacement.
Equally, it needs to be acknowledged that on the balance of probabilities, she would end up with bilateral total knee replacements at some time in the future but the material aggravation from the weight gain would bring forward the need for the surgery, by at least five years.”
[33] ARD p 65.

In his second report dated 20 April 2020, Dr Giblin said[34]:
[34] ARD p 66.

“In 2003 she had a job as an aged care worker.
This environment entailed lifting, squatting and twisting. Her knees were slightly sore, the right worse than the left. She weighed 80 kilos at the time.
The symptoms caused her to seek medical advice and she had a right knee arthroscopy followed by 2 weeks off work. No claim was made. Both her knees remained sore and she just put up with them.
After her lumbar spinal operation, she put on a lot of weight and lost her physical independence and stayed off work. She notes that at this stage, the knee pain became more severe and a greater clinical problem so that she sought advice and had bilateral total knee replacement surgery.”

Mr Nicholson said that Dr Giblin was provided with assumptions about Ms Walsh’s work, activity and weight to prepare his report dated 3 November 2020. He said:

“In relation to the question of increased weight bearing, it should be noted, that whatever mechanism or pathology, alters and increases the weight bearing on the knees, will be associated with an acceleration of any pre-existing or asymptomatic age related changes.
…
It would be my view that the accepted work related injury to the low back, occurring on 23 March 2009, and the subsequent surgery, would have set in train, effectively, a domino series of events, the cumulative nature of which being altered gait mechanics and weight gain, would be more than sufficient to produce symptomatic injury to both knees.
As such, it would be my opinion that the knee conditions are consequential in nature, and result from the primary injury at work to the low back 23 March 2009.
That is to say, there are consequential conditions to both right and left knees as a result of the subject injury to the lumbar spine 23 March 2009, for the reasons as given above.”

Mr Nicholson said that I would prefer Dr Giblin’s opinion over that of Dr Powell who said that the condition was not consequential nor materially aggravated by work. He said that Ms Walsh had no problem with her knees in a real sense until she suffered a back injury and gained weight.

Mr Barter

Mr Barter acknowledged that Ms Walsh had suffered a serious back injury in 2009. He said that Dr James’ first report dated 22 September 2015 set out his diagnosis of bilateral osteoarthritis but did not provide any connection between his diagnosis of bilateral osteoarthritis and Ms Walsh’s work.
With respect to the argument that the injury was caused by the nature and conditions of employment, Mr Barter noted that there was an absence of complaints about Ms Walsh’s knees before ceasing work for the back injury or in the period between her return to work following back surgery on 29 October 2011[35] and when she ceased work in mid-May 2012. There was no reference to her knees in the statement dated 7 August 2012. On that basis, he said that I could only be satisfied that Ms Walsh suffered an injury as a result of the nature and conditions of her employment if I was prepared to draw an inference from the general nature of her duties. There was no explanation, however, why she did not complain of symptoms for another nine months and that therefore I would not draw that inference.
[35] Statement at [14], ARD p 25.
Mr Barter noted that the claim in respect of a consequential condition was made on two bases. He said that I would not accept the argument that it resulted from an increase in weight because there was no evidence of a massive increase in the nine months between Ms Walsh ceasing work in May 2012 and the first complaints about her left knee in January 2013. He said there was evidence that an increase in weight had occurred over several years.
Mr Barter said that there was similarly no evidence in the period from 2012 to January 2013 to support the argument that Ms Walsh had suffered a condition in her left knee as a result of her altered gait. In her first statement dated 7 August 2012, she made no complaint in respect of her knees, which indicated they were possibly asymptomatic. The first complaint about her left knee was on 29 January 2013 so that it could not be said that the nature and conditions of her employment until 2012 contributed to that condition nor that the knee symptoms were a consequence of back surgery in 2011.

Dr R Powell’s report is dated 29 September 2020[36]. Ms Walsh told him that she put on a significant amount of weight after the surgery to her lumbar spine which increased bilateral knee symptoms. In response to the contention that the nature and conditions of employment after the back surgery contributed to the knee condition, Dr Powell said:
“The ‘weight bearing’ taken by her knees would have been the same both before and after the surgery and the amount of weight taken by the knees does not change whether she has back pain or has undergone back surgery. It is a result of her mass and gravity. Any altered gait associated with her lower back condition would not be sufficient to alter the biomechanics of the knee and the joint reaction forces sufficiently to lead to the development of degenerative pathology in the knee.”
And
“I acknowledge that increased weight gain can be a factor in the development of degenerative pathology in the weight bearing joints and may increase symptoms related to the degenerative disease processes involving these joints though the weight gain itself is a function of an imbalance between calorific intake and energy expenditure and is not the result of her employment.”
[36] ARD p 239.
Mr Barter said that Dr Powell’s report supported the contention that even if there was weight gain following the back surgery, the resulting mechanics were insufficient to render the underlying condition symptomatic.
Mr Barter said that there was a conspicuous absence of evidence from Ms Walsh’s treating doctors to support the proposition that the aggravation of degenerative changes in her knees was a result of the surgery and its aftermath, including weight gain as a result of lack of activity resulting from that pain.. She saw Dr Wang in May 2012 about the time she ceased work who said he was happy with her recovery from surgery and the state of her spine. He noted that she continued to perform lighter duties on a full time basis.
Ms Walsh saw Dr Chia in February 2013 and obtained a history of right knee pain associated with clicking for two months, which indicated an onset of symptoms in December 2012. Mr Barter said this was an incorrect reference to the left knee. In April 2013 after a left knee arthroscopy, Dr Chia said that Ms Walsh was not complaining of any pain. Mr Barter said that he predicted a total knee replacement. Dr Chia said:
“Anne is extremely happy with the result of her surgery. She tells me she has experienced no further pain since the surgery. I have advised her regarding the severe degenerative change that is already present in her knee. I have also advised her to see a physiotherapist for range of movement and strengthening exercises: I have advised her to avoid high impact activities and to participate - in low impact activities such as cycling, swimming and using a cross trainer in the gym. As you are aware degenerative arthritis is a progressive condition and if she develops symptomatic arthritis in the future a total knee replacement may be required.”
Similarly, when Ms Walsh saw Dr James in 2015, he did not record a history of either weight gain or an altered gait following back surgery. He did note that she had a higher than average body mass index and that she was able to walk without a limp.
Mr Barter said that Dr Giblin’s opinion was based on facts not supported by the evidence and that in the absence of evidence from treating doctors that the consequential condition was caused by either weight gain or altered gait, I would not be satisfied that Ms Walsh had suffered a consequential condition as a result of her back injury. He said that in order to apply the test in Kooragang Cement Ltd v Bates[37] (Kooragang), it was necessary that there be medical evidence that the consequential condition results from the work injury. That evidence was not available in this case.
[37] (1994) 35 NSWLR 452; (1994) 10 NSWCCR 796.

Reply

In reply, Mr Nicholson said that there was evidence of complaints in respect of Ms Walsh’s knees from the end of 2021 and that she had specialist treatment in early 2013.
In 2015, Dr James noted that Ms Walsh had a higher than average body mass index which, Mr Nicholson said, confirmed that her problems with her weight were ongoing. Dr James’ notes for 22 September 2015 record that Ms Walsh was obese.[38] In his report dated 21 November 2019, Dr James said:
“She presented to me with bilateral tricompartmental arthritis of the knees. The development of arthritis in the knees is generally multifactorial. These factors include a genetic predisposition to degenerative change, prior injuries to the knees, meniscal or chondral pathology de novo or as a reflection of mechanical injury, raised BMI or excessive loading.
Mrs Walsh has had a high BMI for many years. Her previous work required frequent bending squatting kneeling activities as I understand it. She has had previous arthroscopies on both knees and presumably partial meniscectomies and or chondroplastys of the femorotibial and patellofemoral joints. Any and all of these factors may well have contributed to her development of progressive degenerative change in both knees.
I was not seeing her at the time of her initial presentations and cannot comment as to the relative contribution of her work to the development of her pathology and symptoms. Perhaps a temporal and cause of relationship could be made by the practitioners involved in her care at the time, her GP and the Orthopaedic Surgeon Dr Chai Yi Yuen Wang (Neurosurgeon).
It is likely that with the back injury and particular following back surgery Mrs Walsh will have needed to rely on bending of the knees and hips to perform activities below waist height level rather than risking further injury or discomfort by flexion of the lumbar spine. It is a general recommendation for health care workers and personal assistants that they bend the knees not at the back. Once again Dr Wang (Neurosurgeon) would be in a better position to comment on this aspect than myself.”
[38] ARD p 273.
Mr Nicholson also referred to the report of Dr S Leitl, orthopaedic surgeon, dated 6 February 2012 which supported the previous claim for permanent impairment compensation in respect of Ms Walsh’s back. Dr Leitl said:

“I consider that her work as a personal care assistant and more specifically the
incident of 24 March 2009 has resulted in the L4/5 disc prolapse and
aggravation of the lumbar degenerative condition.
…
As a PCA in an aged care hostel the nature of duties would include lifting tasks
and bending and twisting her spine and I consider that her work was a
substantial contributing factor in aggravating her lower back degenerative
condition.”

FINDINGS AND REASONS

The standard of proof on the balance of probabilities which applies in the Commission was described by the Court of Appeal in Nguyen v Cosmopolitan Homes.[39] McDougall J, with whom the other members of the Court agreed, said[40]:
[39] [2008] NSWCA 246.
[40] At [55].

“(1)    A finding that a fact exists (or existed) requires that the evidence induce, in the mind of the fact-finder, an actual persuasion that the fact does (or at the relevant time did) exist;

(2)     Where on the whole of the evidence such a feeling of actual persuasion is induced, so that the fact-finder finds that the probabilities of the fact’s existence are greater than the possibilities of its non-existence, the burden of proof on the balance of probabilities may be satisfied;
(3)     Where circumstantial evidence is relied upon, it is not in general necessary that all reasonable hypotheses consistent with the non-existence of a fact, or
inconsistent with its existence, be excluded before the fact can be found; and

(4)     A rational choice between competing hypotheses, informed by a sense of actual persuasion in favour of the choice made, will support a finding, on the balance of probabilities, as to the existence of the fact in issue.”

In order to be persuaded that an injury or consequential condition was suffered, it is necessary that I look to medical evidence to provide a plausible explanation of causation.
Whether Ms Walsh suffered an injury or consequential condition, the tenor of the medical evidence is that she suffered an aggravation of pre-existing degenerative changes. To find in her favour, I need to be satisfied that there was an aggravation of those changes, not merely a manifestation of symptoms or a natural progression of the underlying condition. The fact that the condition arose after Ms Walsh’s back injury does not, of itself, mean that the condition was a result of the condition.

Injury

I accept that Ms Walsh’s job as a personal care assistant was heavy. The claim in the ARD is that she suffered injury to both knees and further injury to her back as a result of her duties after the back injury on 23 March 2009. Mr Nicholson stressed that she experienced no significant problems with her knees before that injury. I agree that the medical evidence does not reveal any complaints apart from a reference to a right knee strain in 2002 and a diagnosis of chondromalacia patella in 2003. There are no other references to knee problems until January 2013, nine months after Ms Walsh ceased work
Ms Walsh suffered an accepted back injury in 2009. She returned to work then suffered a recurrence and underwent surgery in March 2011. There is no contemporaneous statement about that injury because the claim was accepted. She returned to work on 29 October 2011.
Ms Walsh prepared two statements – the first in August 2012 with the assistance of an investigator for her psychological injury claim. The 2012 statement makes no reference to her knees though does say that she returned to work on a return to work plan. The psychological injury was suffered as a result of disciplinary action following alleged breaches of the return to work plan or Work Health and Safety regulations. Neither the statement nor the arbitral and Presidential decisions provide a detailed description of the duties undertaken during that time. That is to be expected because of the nature of the dispute.
The second statement was prepared with the assistance of her solicitor for these proceedings. Ms Walsh said that she returned to work on restricted duties after her back surgery. However, later in her statement she said that she was not performing light duties and that she was required to bend, stoop, kneel, push, squat and perform some lifting. Those statements are difficult to reconcile. Ms Walsh said that she put extra load on her knees rather than risk bending her back.
Dr Wang, saw Ms Walsh in May 2012 and said that she was working on lighter duties. Dr Powell obtained a history in his first report dated 29 September 2020[41] that Ms Walsh returned to work after the surgery on light duties and never regained her full pre-injury duties. Ms Walsh took issue with the suggestion that she was performing light duties in her statement dated 2 June 2021.
[41] ARD p 239.
On balance, I accept that Ms Walsh did not return to her full pre-injury duties after her back surgery.

There is no evidence that Ms Walsh complained of pain in her knees or restricted movement until January 2013, nine months after she ceased employment. Dr Zotov requested and x-ray and on receipt of the results, made a specialist referral.
Ms Walsh was referred to Dr Chia who had a history of pain over the previous two months. He said that it was right knee pain but I accept, as counsel did, that the first treatment was in respect of her left knee. There was no reference to the duties of Ms Walsh’s employment in Dr Chia’s report dated 20 February 2013 and the only opinion he expressed was that she suffered a medial meniscal tear on a background of mild medial compartment osteoarthritis. He said there was no history of recent injury, trauma or falls. He did not make any comment on causation in his report dated 4 April 2013.
Dr James prepared a report dated 21 November 2019 and his opinion is extracted at [53] above. He accepted that Ms Walsh’s weight, work duties or treatment “may well have contributed to the development of progressive degenerative change”. However, he declined to provide a conclude view because he did not see her at the time of her initial presentations and referred Ms Walsh’s solicitors to doctors involved in her treatment at that time.
Dr Giblin did not deal squarely with the claim with respect to knee injury as a result of the nature and conditions of Ms Walsh’s duties in any of his reports. He said in his report dated 3 November 2020[42]
“The issue of returning to pre-surgery duties except for showering patients and mopping floors would raise concerns and considerations in terms of stair climbing. lifting weights, or performing activities which require her to kneel or squat so as to protect her back.”
[42] ARD p 258.
Dr Giblin did not go so far as to say that the duties performed by Ms Walsh did cause injury but merely that they raised concerns. The comment set out above was made in the context of his opinion that increased weight bearing may accelerate degenerative changes.

There is insufficient evidence to persuade me that Ms Walsh suffered an injury to her knees as a result of the nature and conditions of her employment after her back injury in 2009. There is no probative medical evidence to link the condition with the nature of her duties and there was a significant gap between ceasing work for other reasons and the first complaints.

Consequential condition – altered gait

In the alternative to the claim that she suffered injury to her knees as a result of the nature and conditions of her employment, Ms Walsh claims that she suffered a consequential condition in both knees, either as a result of an altered gait following back surgery or as a result of weight gain. In order to find that she did suffer such a condition, I must be satisfied that there is a chain of causation between Ms Walsh’s back injury and the condition in her knees. That requires an explanation of the causal chain, not merely a statement of the result.
In Kooragang, Kirby P said that “[f]rom the earliest days of compensation legislation, it has been recognised that causation is not always direct and immediate”[43]. His Honour said:
“Since that time, it has been well recognised in this jurisdiction that an injury can set in train a series of events. If the chain is unbroken and provides the relevant causative explanation of the incapacity or death from which the claim comes, it will be open to the Compensation Court to award compensation under the Act.”
[43] At [461G].
Kirby P said[44] :

“The result of the cases is that each case where causation is in issue in a workers’ compensation claim, must be determined on its own facts. Whether death or incapacity results from a relevant work injury is a question of fact. The importation of notions of proximate cause by the use of the phrase ‘results from’, is not now accepted. By the same token, the mere proof that certain events occurred which predisposed a worker to subsequent injury or death, will not, of itself, be sufficient to establish that such incapacity or death ‘results from’ a work injury. What is required is a commonsense evaluation of the causal chain. As the early cases demonstrate, the mere passage of time between a work incident and subsequent incapacity or death, is not determinative of the entitlement to compensation. In each case, the question whether the incapacity or death ‘results from’ the impugned work injury (or in the event of a disease, the relevant aggravation of the disease), is a question of fact to be determined on the basis of the evidence, including, where applicable, expert opinions. Applying the second principle which Hart and Honoré identify, a point will sometimes be reached where the link in the chain of causation becomes so attenuated that, for legal purposes, it will be held that the causative connection has been snapped. This may be explained in terms of the happening of a novus actus. Or it may be explained in terms of want of sufficient connection. But in each case, the judge deciding the matter, will do well to return, as McHugh JA advised, to the statutory formula and to ask the question whether the disputed incapacity or death ‘resulted from’ the work injury which is impugned.”

[44] At [463]-[464].

In Bouchmouni v Bakhos Matta t/as Western Red Services[45], Roche DP said:

“It may be seen that if an ‘injury’ sets in train a series of events then, if the chain is unbroken and provides the relevant causative explanation for the incapacity or impairment, compensation is payable .... That does not mean that the condition that provides the relevant causative explanation for the incapacity or impairment is an ‘injury’.
The fact that the worker in Kooragang died from a heart attack did not mean that the heart attack was an ‘injury’. It meant that, on the facts of that case, there was an unbroken chain of causation between the back injury and the death. In other words, the heart attack (and death) resulted from the back injury.”

[45] [2013] NSWWCCPD 4.

Ms Walsh’s evidence with respect to an altered gait is presented as a conclusion, rather than a factual description of how her gait altered. She said:

“I noticed upon my return to work my gait altered and my knees became swollen and painful.”[46]
[46] ARD p 6 – statement [45].

In that form, the evidence is not probative. There is no contemporaneous factual or medical evidence describing whether or how Ms Walsh’s gait altered and how that resulted from her back injury.
The contention that Ms Walsh suffered an altered gait is inconsistent with Dr Wang’s report dated 25 May 2012 in which he said that he was happy with the result of the back surgery, though he did concede that she had some ongoing symptoms.
When Dr James saw Ms Walsh for the first time in 2015 he noted that she walked without a significant limp.
There is also no later evidence to provide the relevant causal link.
Dr Giblin recorded in his first report dated 21 October 2019[47] that Ms Walsh walked with a slightly short stepped gait but no frank limp. Somewhat inconsistently, he said[48]:
“Her altered gait pattern in relation to the operation on the right knee and the limp in her left leg would also be a material consideration in terms of the acceleration of arthritis in the left knee.”
[47] ARD p 60.
[48] ARD p 65.
Unless it is accepted that the right knee surgery was a consequence of the back injury and its aftermath, that statement does not support the contention that Ms Walsh suffered a consequential condition.
The letter from Ms Walsh’s solicitors dated 26 October 2020 seeking a further report asked Dr Giblin to assume:

“…
3.      Between 23 March 2009 and 3 August 2011, a period of approximately 2 years and 5 months, the worker compensated for her back by using her knees more to take the pressure off and lessen the pain from her injured back;
4.      From 3 August 2011 until the date she was terminated from her employment in May 2012 the worker gained over 20 kg in weight and had an altered gait.
5.      Our client upon her return to work following back surgery was performing all her pre-injury tasks as a personal care assistant except showering patients and mopping floors. It was heavy work.”

As set out above, those assumptions are not made good by the contemporaneous evidence. Dr Giblin’s opinion in his report dated 3 November 2020[49] accepted that the condition was a result of increased weight bearing and an altered gait but did not explain why. He said:

“It would be my view that the accepted work related injury to the low back, occurring on 23 March 2009, and the subsequent surgery, would have set in train, effectively, a domino series of events, the cumulative nature of which being altered gait mechanics and weight gain, would be more than sufficient to produce symptomatic injury to both knees.”
[49] ARD p 621.

In the absence of a clear explanation of his opinion, I do not accept Dr Giblin’s opinion that an altered gait was a contributing factor to the development of a consequential condition. In South Western Sydney Area Health Service v Edmonds[50] McColl JA described the requirements for expert evidence in the Workers Compensation Commission:
[50] [2007] NSWCA 16 at [130]-[132].

“In Hevi Lift (PNG) Ltd v Etherington at [84] I said (Mason P and Beazley JA agreeing) that ‘[a] court should not act upon an expert opinion the basis for which is not explained by the witness expressing it’. In so saying, I referred with approval (inter alia) to Heydon JA’s analysis of the admissibility of expert evidence in Makita (Australia) Pty Limited v Sprowles (at [59] – [82]). In that case (at [59]) Heydon JA cited with apparent approval Lord President Cooper’s statement in Davie v The Lord Provost, Magistrates and Councillors of the City of Edinburgh (1953) SC 34 at 39-40 that:
‘… the bare ipse dixit of a scientist, however eminent, upon the issue in controversy, will normally carry little weight, for it cannot be tested by cross-examination nor independently appraised, and the parties have invoked the decision of a judicial tribunal and not an oracular pronouncement by an expert.’
This statement is apposite in the context of Commission hearings, and, indeed, is implicitly recognised in r 70. While it must be recognised that ‘[t]here is no legal right to cross-examine an applicant or other witness in the Workers Compensation Commission and decisions whether to allow cross-examination or to limit it are discretionary’ (Aluminium Louvres & Ceilings Pty Limited v Xue Qin Zheng [2006] NSWCA 34 at [37]), the fact that cross-examination of an expert witness may be permitted indicates the desirability of expert reports conforming as far as possible to common law standards of admissibility designed to ensure they have probative value. Even if that is too stringent an approach in the face of s 354, as the rules recognise, evidence must be ‘logical and probative’ and ‘unqualified opinions are unacceptable’.

In my view Dr Rivett’s statement that ‘in general all the problems are work-related’ which the Arbitrator accepted in concluding that the respondent’s duties were sufficient to cause her injury (apparently within the meaning of s 16) amounted to a bare ipse dixit. It was not probative of the issue before the Arbitrator.”

The requirements that evidence be logical and probative and that unqualified opinions are unacceptable have been carried forward to the Personal Injury Commission in rule 73 of the Personal Injury Commission Rules 2021.
In the absence of any description of Ms Walsh’s altered gait or path of reasoning to explain his opinion, Dr Giblin’s view is not probative.
I cannot be satisfied that Ms Walsh suffered an altered gait as a result of back surgery. There is no evidence to show that it led to an acceleration of the underlying degenerative process. I therefore do not accept that she suffered a consequential condition in her knees as a result.

Consequential condition – weight gain

The evidence with respect to weight gain is also not persuasive. Ms Walsh’s first statement does not deal with the issue, nor would that be expected. In her statement dated 2 June 2021, Ms Walsh said that she had gained nearly 20 kg in weight from 85 kg to 104 kg after the surgery. She said that the reason was because she was inactive whilst recuperating from surgery and that her labour-intensive duties had previously kept her fit.[51] The latter comment is inconsistent with her statement that she returned to practically full duties in October 2011.
[51] ARD p 6 – statement [47].
As Mr Barter said, there is an absence of evidence on the issue of weight gain from Ms Walsh’s treating doctors. There are no records of her weight in the general practitioners’ notes and there is no reference to weight gain.
Dr Zotov prepared a report dated 15 September 2019 for Ms Walsh’s solicitor.[52] He extracted records relating to a number of consultations relating to her psychological injury. He was asked[53]:
“Our client has informed us that due to the back injury suffered on 23 March 2009 she now suffers from painful knees. Please provide your opinion as to whether our client's weight gain, radiculopathy and change of gait, due to back injury has contributed to the pain, operations to her right knee and discomfort she is now suffering to both knees?”
[52] ARD p 605.
[53] ARD p 604.
Dr Zotov said:

“I am not sure does back injury in 2009 related to painful knees condition, but I believe that poor mobility or immobility may contribute to weight gain with more mechanical pressure to the spine and knees.”

That statement does not assist Ms Walsh’s case, particularly when Dr Zotov was best placed of any of the doctors who have treated Ms Walsh to comment on the cause and progress of weight gain.
Dr James recorded in his notes at the time of his first consultation that Ms Walsh was obese[54] and said in his initial report that she had a higher than average body mass index. He did not record that it was a result of inactivity after the back surgery. As set out above, Dr James declined to offer an opinion on the causation of Ms Walsh’s knee condition.
[54] ARD p 273.
There are no other references to weight gain in the reports of Ms Walsh’s treating practitioners.
Ms Walsh saw Dr M Wearne for the Council’s insurer on 10 June 2011, before the back surgery. He recorded that Ms Walsh told him that she “keeps good general health, apart from a weight problem.”[55] He noted that she weighed 99 kg.
[55] ARD p 184.
Dr Leitl examined Ms Walsh in February 2012 for her first permanent impairment claim – that is during the period between the back injury and the complaint of knee pain. He obtained the history that Ms Walsh was undertaking physiotherapy. Her husband did heavier domestic work such as vacuum cleaning but they shared cooking and ironing. She was able to drive for an hour. He recorded that she weighed 98 kg but did not otherwise comment on her weight.
In his first report, Dr Giblin recorded that at the time of the original injury, Ms Walsh weighed 90 kg and that “following her injury and operation” her weight increased to 115 kg and she developed bilateral knee pain. At the time of his consultation in 2019, she weighed 96 kg. he considered that weight gain following the 2009 injury was a material aggravating factor of her pre-existing right knee arthritis.
In his second report dated 20 April 2020, Dr Giblin recorded that Ms Walsh commenced employment in 2003, that she weighed 80 kg and that her knees were slightly sore. He said:
“After her lumbar spinal operation, she put on a lot of weight and lost her physical independence and stayed off work. She notes that at this stage, the knee pain became more severe and a greater clinical problem so that she sought advice and had bilateral total knee replacement surgery.”
That history is not supported by the facts of Ms Walsh’s return to work between October 2011 and May 2012 and that there was no complaint of knee pain until January 2013.
The assumptions Dr Giblin was asked to make for the preparation of his report dated 3 November 2020 are set out at [81] above. Dr Giblin relied on those assumptions without taking his own history. Based on the assumption of weight gain, he accepted that the knee conditions were a consequence of the back injury.
Dr Giblin’s opinion is not probative for the same reason that his opinion with respect to her altered gait was not probative. There is inadequate factual evidence to support the assumptions on which he relied.
In the absence of detail in Ms Walsh’s statement and in the absence of comment on her weight by her treating doctors, I am not persuaded that she suffered a significant weight gain which was a result of a lack of mobility after back surgery.
None of Ms Walsh’s treating doctors provide any comment about the relationship between Ms Walsh’s work and the need for surgery to her knees. The tenor of their reports is that the operations were necessary as a result of the degenerative changes she suffered and not because of any aggravation of those changes as a result of her employment or her back injury.
I therefore make these orders:
(a)    Award for the respondent on the claim that Ms Walsh suffered a consequential condition in her left and right knees.
(b)    I remit the matter for referral to a Medical Assessor to assess Ms Walsh’s permanent impairment as a result of an injury to her lumbar spine on 23 March 2009.
(c)    Note that a face to face examination will be necessary.
(d)    I direct that the parties prepare an agreed bundle of documents for the Medical Assessor within 21 days.

[2021] NSWPIC 383

29 September 2021