Woolworths Group Limited v Whittaker
[2022] NSWPICMP 110
•10 May 2022
| DETERMINATION OF APPEAL PANEL | |
| CITATION: | Woolworths Group Limited v Whittaker [2022] NSWPICMP 110 |
| APPELLANT: | Woolworths Group Limited |
| RESPONDENT: | Janelle Margaret Whittaker |
| APPEAL PANEL: | Member Paul Sweeney Dr John Brian Stephenson Dr Tommasino Mastroianni |
| DATE OF DECISION: | 10 May 2022 |
| CATCHWORDS: | WORKERS COMPENSATION- Employer’s appeal against failure of the Medical Assessor (MA) to make a deduction for a pre-existing condition pursuant to section 323 (1) of the Workplace Injury Management and Workers Compensation Act 1998 in respect of whole person impairment (WPI) resulting from total replacement of worker’s osteoarthritic right knee; worker had a long history of right knee problems including two significant surgical procedures and a diagnosis of osteoarthritis before performing the work tasks which aggravated her knee; Held- that the MA had erred in not engaging with this medical history and in failing to make a deduction to reflect pre-existing osteoarthritis; determined that the worker’s employment and her pre-existing condition contributed equally to her WPI; Medical Assessment Certificate revoked. |
BACKGROUND TO THE APPLICATION TO APPEAL
On 15 December 2021, Woolworths Group Limited (the appellant) lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Neil Berry, a Medical Assessor (MA), who issued a Medical Assessment Certificate (MAC) on 19 November 2021.
The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (1998 Act):
· the MAC contains a demonstrable error.
The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The appeal panel has conducted a review of the original medical assessment but limited to the grounds of appeal on which the appeal is made.
The Personal Injury Commission Rules 2021 (the PIC Rules), and Procedural Direction PIC7 – Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with the PIC Rules.
The assessment of permanent impairment is conducted in accordance with the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed 1 April 2016 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed (AMA 5).
RELEVANT FACTUAL BACKGROUND
Janelle Margaret Whittaker (the respondent) has a long history of problems with her right knee. According to her initial signed statement of 18 July 2018, she dislocated that knee when she was 19 years of age while working at Flemings. In September 1997, she underwent a right patella-femoral reconstruction under Dr David Wood. In June 2006, she fell at home and tore a meniscus in her right knee. The respondent says that she underwent arthroscopic surgery following that incident. She states that following the surgery she had “no ongoing problems until my work-related right knee injury”.
The respondent has also experienced difficulty with her feet and back following a work injury on 16 January 2005. Following that injury a bone scan revealed stress fractures in both her feet. As her right foot was worse than her left, it was put in plaster. When the plaster was removed the respondent underwent physiotherapy.
When the respondent’s feet did not improve with conservative treatment, including the prescription of orthotics, she was referred to Dr Sorrenti, an orthopaedic surgeon who advised that there was no operative remedy to her pain. However, her right foot was placed back in plaster for another period of 3 months.
During this time the respondent ambulated on crutches. It is accepted that as a result of altered gait while using crutches she developed problems in her low back.
On 10 September 2007, the appellant was ordered to pay the respondent the sum of $18,500 in respect of 14% whole person impairment (WPI) in respect of the injuries to her feet, ankles and lumbosacral spine as a result of the injury on 16 January 2005.
Following these injuries the respondent returned to work on permanently modified light duties. According to her statement these involved working in the cash office. She states that:
“This position was mostly seated.”
The respondent states that in 2009 she was placed on check-out work for a period of two hours each shift during which she was “required to stand for [sic] continuously in the one spot”. As a consequence of this work and favouring her injured right foot she “developed an increasing amount of left knee pain”.
In September 2010, the respondent saw Dr Sorrenti, the orthopaedic surgeon who performed an arthroscopy on her right knee. Following this, she was again placed on permanently modified duties.
In 2013, Dr Tang, her general practitioner, certified that she was:
“fit for permanently modified duties, namely office work, marking down duties for up to 60 minutes per shift, and explicitly no register duties.”
Nonetheless, the respondent continued to experience pain in her knee for which she was told to “hold out as long as possible before undergoing surgery”.
The respondent says that in 2014 her hours of work increased to 36 hours a week. She was also told to perform supervisory duties which required her to walk around the store and to do “increased cash register duties”.
The respondent says that her left knee has improved since surgery. However, as a result of her change in duties in 2014, she developed right knee pain. Her statement includes the following:
“As a result of the change of duties in 2014 I developed pain in my right knee. This has been exacerbated by the left knee difficulties I was experiencing and then favouring the left knee following surgery in 2017.”
On 18 May 2017, the respondent underwent a total left knee replacement under Dr Fred Nouh, an orthopaedic surgeon, at Campbelltown Private Hospital. She returned to work 12 weeks after the surgery.
On 28 August 2017, the respondent says that she “bent down to pick an object off the floor when she experienced a sudden pain in her right knee”. She made a claim for compensation in respect of her right knee. However, this claim was declined.
On 4 October 2018, Dr Nouh performed a total right knee replacement at Campbelltown Hospital. Again, the respondent returned to work 12 weeks after the surgery.
By a supplementary statement of 6 May 2021, the respondent says that she returned to work some 12 weeks after her right knee replacement surgery on 1 November 2018. She says that she is able to work 36 hours per week from Wednesday to Sunday.
On 5 June 2018, Dr Giblin, an orthopaedic surgeon saw the respondent at the request of her solicitor. He took a history that:
“In 2015 she developed right knee pain. She believes this was due to the fact that she was taken out of the office and put into check-out work where she had to stand for 8 hour shifts.”
Dr Giblin expressed the opinion that:
“The injury to her right knee is due to the nature and conditions of her work environment as being the main contributing factor but is superimposed upon pre-existing injury to the right knee. This has been an acceleration of that underlying degeneration.”
By a supplementary report dated 10 December 2019, Dr Giblin recorded that the respondent had undergone a right total knee replacement on 2 October 2018. She returned to work on 1 January 2019 and continues to perform full-time hours as a cashier. He said this:
“It remains my opinion, that her work environment on continual standing and walking, is the substantial contributing factor to both her left and right knee injuries.”
He assessed both the right and left knees for permanent impairment. He assessed the right knee as 20% WPI. He stated:
“I have made no deduction under section 323 on the basis that the disease was contracted by the worker in the course of the employment and it is only the employment which is the main contributing factor to the contraction of the disease.”
However, by a supplementary report bearing date 4 March 2021 he expressed the opinion that the single injury which occurred in 2005 was:
“an index injury that had the effect of being a domino to fall and then set up the sequence of events as outlined in the body of my initial report. That is to say, if it were not for the initial injury of 2005, in my view it is unlikely that Mrs Whittaker’s bilateral knee injuries would have occurred, in the timeframe that has been outlined.”
Dr James Powell, an orthopaedic surgeon, saw the respondent at the request of the appellant’s solicitors on 26 August 2020. He recorded an incident in 2010 when the respondent tripped at work injuring her left knee, although she could not remember the circumstances of the incident. He records that the respondent:
“developed pain in the knee which gradually increased in severity to the point that she had difficulty taking any weight on her knee.”
Dr Powell noted that at a previous appointment, in September 2017, the respondent had stated that she had developed pain in her left knee because of increased load on the left knee following the injury to her right foot in 2005. In respect of the right knee he recorded the following history:
“Ms Whittaker’s right knee started to trouble her in March 2017, just before her left knee replacement. She slipped on some lettuce at the register that had been left by a customer. Her right knee came out from under her and to protect her left knee she landed on her flexed right knee which caused pain in the knee.”
Dr Powell noted that the respondent had:
“developed difficulties at the right knee around the age of 19 (1980) which she had previously described as a knee dislocation but almost certainly given subsequent descriptions and imaging was a patella-femoral episode. Whether it was a dislocation or not is unclear.
Ms Whittaker subsequently came to an extensor mechanism realignment procedure in 1994 under the care of Dr Wood, orthopaedic surgeon, which would explain the screws in the proximal tibia prior to her joint replacement indicating that she had a distal and most likely associated proximal realignment procedure.
This would also explain the patella baja in the right knee.”
Dr Powell also recorded that the respondent had also undergone an arthroscopic medial meniscectomy and chondroplasty in 1998, although it is more likely that this surgery occurred in 2006, as recorded in the notes of Dr Tang and the respondent’s statement of 13 November 2006.
Dr Powell expressed the opinion that the respondent had bilateral osteoarthritis of both knees. He continued:
“This condition is age and constitutionally related and in her particular case, the most significant constitutional factor is obesity. Although Ms Whittaker indicated that her obesity was only of recent onset, the contemporaneous evidence indicated that it was well-established at the same level as it currently is in 2010.”
Dr Powell expressed the opinion that the respondent had 20% WPI. However, he expressed the opinion that the impairment related entirely to pre-existing disease factors causing Ms Whittaker’s arthropathy. He said this:
“There has been no specific incident in her workplace influencing the natural history of her arthropathy, nor are the nature and conditions of her work sufficient to influence the natural history of her arthropathy and the need for joint replacement, neither through cause, aggravation, acceleration or deterioration.”
The differing opinions between Dr Giblin and Dr Powell as to the degree of WPI gave rise to a medical dispute as that term is used in s 319 of the 1998 Act. Accordingly, a delegate of the President referred the matter to an MA for determination. It is from the certification of Dr Berry that the appellant appeals.
PRELIMINARY REVIEW
The appeal panel conducted a preliminary review of the original medical assessment in the absence of the parties. As a result of that preliminary review the panel determined that it was unnecessary for the worker to undergo a further medical examination. Neither party sought a re-examination of the respondent by a medical practitioner who is a member of the panel.
As the issue in dispute is whether a deduction for a pre-existing condition should be made pursuant to s 323 of the Workers Compensation Act 1987 (the 1987 Act), a further medical examination would not have assisted the panel in elucidating the respondent’s medical history. The panel had available much of the evidence relating to the respondent’s long history of knee problems. It is unlikely that a further enquiry into this history would be profitable.
EVIDENCE
The panel has before it all of the documents which were sent to the MA for the original medical assessment and has taken them into account in making this determination.
Medical Assessment Certificate
The parts of the medical certificate given by the MA which are relevant to the appeal are set out in the body of this decision.
SUBMISSIONS
Both parties made written submissions. They are not repeated in full but have been considered by the appeal panel. In summary, the appellant submits that the MA erred in failing to make a deduction for a pre-existing osteoarthritic condition of the respondent’s left knee pursuant to s 323. The appellant submits that the error was characterised by:
(a) failing to take a history of, or pay due regard to the evidence of injury to the right knee prior to the respondent’s commencement of employment with the appellant;
(b) failing to take a history of, or pay due regard to the evidence of injury to the right knee sustained whilst employed with the appellant but which was unrelated to the injury the subject of the referral, and
(c) failing to consider whether there should be apportionment of impairment for a subsequent or unrelated injury.
In respect of failure to take a correct history the appellant notes that the MA recorded a history of injury to the right knee as a result of “fall at work in the checkout area”. The appellant asserts that this history is at odds with the balance of the evidence, including the worker’s statements, which contain no history of an injury to the right knee.
The appellant then refers to the references to previous right knee surgery in the worker’s statement. It also referred to serial medical reports which demonstrated the presence osteoarthritis of the knee from late 2006. It referred to the opinion of Dr Jones of 14 June 2011 in which the doctor discussed an arthroscopic meniscectomy and chondroplasty procedure which the respondent underwent. Dr Jones is recorded as stating:
“Ms Whittaker is a 49-year old woman who has long-established patella-femoral osteoarthritis in both knees.”
After discussing the extensive medical evidence in the case the appellant submitted that there could be no doubt that the MA “failed to engage with the above evidence”. Further, there was no analysis at all of any of this evidence in the MAC. It continues that:
“had the MA cross referenced the “(incorrect history) with the evidence before him we imagine he would have held grave doubts about what he was told.”
In summary the respondent worker submitted that the MA was “clearly alive” to the issue of the respondent’s prior knee pathology and the appeal was an attempt to “impermissibly cavel with the opinion of the MA”. She referred to a number of cases that had discussed the meaning of “demonstrable error” in s 327(3)(d) of the 1998 Act. She submitted that it was not readily apparent that the MA failed to have regard to non-work causation of right knee pathology.
The respondent noted that the MA had regard to the radiological investigations and concluded that she had developed osteoarthritis of both knees. He also considered Dr Giblin’s opinion on causation thus:
“Although there were arthritic changes, these were, in and of themselves, changes arising in the course of and because of work and assessable accordingly.”
The respondent then submits the worker disclosed and tendered in evidence in respect of the “prior issues in relation to her right knee. It submits that a credit attack should not be made on the worker in a medical appeal. In any event the respondent had disclosed in her statements her previous surgical history.
The respondent maintains that the material does not demonstrate error on the part of the MA in the sense that that concept is understood by the authorities. In the alternative it says that if a deduction is to be made a one tenth deduction is appropriate.
FINDINGS AND REASONS
Section 328(2) of the 1998 Act provides that an appeal is to be by way of review of the original medical assessment, but the review is limited to the grounds of appeal on which the appeal is made. This subsection was considered by Davies J in New South Wales Police Force v Registrar of the Workers Compensation Commission of New South Wales [2013] SC 1792 (11 December 2013). Davies J considered that the form of the words used in s 328(2) of the 1998 Act ‘the grounds of appeal on which the appeal is made’ was intended to convey that the appeal is confined to those particular demonstrable errors identified by a party in its submissions. The panel has only considered those grounds specifically raised by the appellant in her application.
In Campbelltown City Council v Vegan [2006] NSWCA 284 (Vegan), the Court of Appeal held that the appeal panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
The role of the medical appeal panel was considered by the Court of Appeal in Siddik v WorkCover Authority of NSW [2008] NSWCA 116. An appeal by way of review may, depending upon the circumstances, involve either a hearing de novo or a rehearing. Such a flexible model assists the objectives of the legislation. However, in Versace vAustralia Best Tyres & Auto Pty Limited [2016] NSWSC 1540 (2 November 2016) Schmidt J, held that the 1998 Act did not permit the panel to review the determination of the MA without first identifying error.
Though the power of review is far ranging it is nonetheless confined to the matters which can be the subject of appeal. Section 327(2) of the 1998 Act restricts those matters to the matters about which the MAC is binding. In considering the submissions of the appellant, it is necessary to bear in mind the nature of the statutory obligation of the MA to provide reasons. It is evident from reasoning of the High Court of Australia in Wingfoot Australia Partners PtyLtd v Kocak [2013] HCA 43 (Wingfoot) that it is only necessary for the MAC to explain the actual path of reasoning of the MA in sufficient detail to enable a court or an appeal panel to determine whether there is error in its findings. In Wingfoot it was said that:
“The function of a medical panel is neither arbitral nor adjudicative: it is neither to choose between competing arguments, nor to opine on the correctness of other opinions on that medical question. The function is in every case to form and give its own opinion on the medical question referred to it by applying its own medical experience and its own medical expertise.”
The reasoning in Wingfoot has been applied to medical assessments under the NSW Workers Compensation legislation: see, for example El Masri v Woolworths Ltd [2014] NSWSC 1344 (26 September 2014).
By her submission on this appeal, the respondent states that:
“As a result of various injuries at work which are deposed to in the body of the statement, including altered gait, she developed back (pain) in her right knee in 2014 – after a change in her duties as imposed on her by the appellant in light of her various limitations.”
The panel assumes that the reference to back in the above quote should read “pain” and has included that word in italics in the quotation.
At the telephone conference before Member Haddock on 25 August 2021, the Application to Resolve a Dispute was amended to delete what there appeared and insert:
“The nature and conditions of employment up to 10 December 2019”.
The matter was remitted to the President for referral to an MA on that basis. It was noted that the parties agreed that:
“Any assessment of whole person impairment with respect to injury on 10 December 2019 is not to be aggregated with the assessment of whole person impairment with respect to injury on 16 January 2005.”
On 26 August 2021, the referral for assessment utilised the same language as the orders in the Certificate of Determination.
Thus, the medical dispute which was referred for assessment was the permanent impairment of the respondent’s extremities (knees) resulting from the nature of work over the years or, alternatively, from a disease in accordance with ss 15 or 16 of the 1987 Act. There is no pleading that encompasses a frank injury with the exception of the injury in 2005 in which the respondent injured her feet/ankles and consequentially her back.
In the MAC the MA recorded the following history of injury to the respondent’s right knee.
“In 2017 she had a fall at work in the check-out area and injured her right knee. Again no time was lost but the patient found that she was walking very uncomfortably and so she attended her doctor and was referred to Dr Fred Nouh, orthopaedic surgeon. Dr Nouh arranged for her to have scans done of both knees and indicated that in both knees the situation was bone on bone and that she required total knee replacements”.
In respect of the previous or subsequent injuries or conditions, the MA recorded:
“Ms Whittaker has had an accident in 2005 when she fell over a pallet jack and injured her right and left ankles. She was found on x-ray to have bilateral navicular fractures. She was treated with mobilisation and crutches and has been left with continuing pain in the right ankle. A claim has been made and settled. Apart from that, there are no other claims or injuries that the patient is aware of.”
Against that background the MA, commented:
“I have made no deduction from this assessment as the patient has carried out her required duties through the years, despite the falls and as far as I can determine there is no pre-existing condition that needs to be deducted.”
Although he refers to the report of Dr Giblin dated 5 June 2018, the MA makes no reference in his report to the fact that the relevant medical history of the appellant’s right knee includes a dislocation at aged 18, significant right knee surgery in the late 1990s by way of a patella-femoral reconstruction, and arthroscopic meniscectomy and chondroplasty surgery to the right knee under Dr Wood on 31 October 2006. He makes no reference to the radiological evidence of right knee osteoarthritis before the respondent alleges that she injured it at work.
It is true that there are no contemporaneous medical reports that describe the respondent worker’s right knee pathology or the precise nature of the surgical procedure in the late 1990s. However, it is quite clear that the respondent had osteoarthritis in her right knee by 2005. Dr Tang recorded on 24 November 2005 that the respondent had right knee pain. He noted that:
“had R patellofemoral reconstruction 8 years ago.
X-rays ordered.”
On 3 December 2005, Dr Tang reported that the respondent had osteoarthritis in her right knee. A further X-ray report of 24 July 2006 demonstrated:
“Surgical screws are noted in the upper tibia at the site of the previous reconstructive surgery … mild OA changes are noted involving the medial tibio-femoral joint space compartment as well as the patella-femoral joint.”
On 13 November 2006, the respondent provided a statement in relation to the 2005 injury to her feet/ankles. She referred to the fact that she had recently had surgery to her right knee under Dr Wood. She said that her right knee condition was not stopping her from working. She also stated:
“I have had ongoing trouble with my right knee over the years and this is not work-related.”
On 30 July 2008, the respondent complained to Dr Cheng of right knee pain for which she had had multiple surgeries and was not “keen for more surgery”.
The panel notes that Dr Giblin, the respondent’s qualified surgeon, expressed the opinion that although the nature of the respondent’s work involving standing and walking was the main contributing factor to an aggravation of the respondent’s right knee arthritis it was “superimposed upon pre-existing injury to the right knee”.
Similarly, Dr Nouh referred to the respondent having increasing pain in her right knee on 7 August 2017 “on a background of multiple previous operations of the right knee”.
Plainly, there is a great deal evidence which suggests the possibility of a previous condition of the right knee which might lead to the necessity of making a deduction pursuant to s 323 of the 1998 Act. There is no suggestion in the MAC that the MA considered this evidence in reaching his determination. The failure to engage with a substantial body of relevant evidence is a demonstrable error. It is an error that is apparent on the face of the MAC.
Conversely, the MA took a history of a frank injury or injury simpliciter in 2017, when she slipped and fell at work. That injury was not referred to in the respondent’s statements and was not particularised in the respondent’s Application to Resolve a Dispute. There is no contemporaneous medical account of this fall. Dr Giblin did not refer to it in his report which assesses WPI. It is not apparent that it formed part of the medical dispute between the parties.
It is the respondent’s case set out in her statement’s and in her history to Dr Giblin that she experienced right knee pain at work in 2014 when she was “taken out of office duties”. She was required to perform supervisory work which involved her in walking within the store during her hours of employment which had been extended to 36 hours per week. Her right knee pain was “exacerbated by the left knee difficulties I was experiencing”.
The pleadings, the medical evidence and the referral establish the nature of the medical dispute between the parties: see generally Sleiman v Gadalla Pty Ltd [2021] NSWCA 236 (30 September 2021).
It is possible that the origins of the respondent’s right knee osteoarthritis relate to the malfunctioning of her right knee and the surgery that she underwent in the late 1990s to realign her patella. It is also possible that it was exacerbated by the fall at home and the surgery in in 2006. It is unnecessary, however, to determine the precise origins of the osteoarthritis. However, in the opinion of the panel the MA erred in failing to determine that there was a relevant pre-existing condition and to make a deduction in respect of that condition in the MAC.
The case law in relation to the application of the s 323 is well known. Several of the important cases were referred to by the MAP are set out in the decision of Broadspectrum (Australia) Pty Ltd v Fiona Louise Wills [2018] NSWSC 1320 (31 August 2018). The quotation at [46] is as follows:
“22. The first task for the AMS, as Campbell J notes in Greater Western Area Health Service v Austin[2014] NSWSC 604 is to assess the body parts referred,“An Approved Medical Specialist's task is to assess the whole person impairment with which the injured worker presents. Whether it be caused by the injury or whether its cause is from an unrelated source, nonetheless the impairment should be recorded. If it is the opinion of the AMS that the losses, or part of them, had been caused for other reasons then an AMS has the power to make an appropriate deduction under s 323 of the 1998 Act, or to vary his assessment as provided at [8(g)] of the MAC.
23. In Ryder v Sundance Bakehouse[2015] NSWSC 526, Campbell J said,
“Section 323 as I have already said, requires there to be a deduction for any proportion of the impairment that is due to any pre-existing condition. This is an essential element of the section; indeed it is the pith of it. It is not enough to simply identify that there is a pre-existing condition and that there has been a subsequent impairment and therefore make a deduction under this section because of the existence of the pre-existing condition. Such reasoning fails to consider a necessary condition of the operation of the section; that a proportion of the permanent impairment is due to the pre-existing condition.”
In Cullen v Woodbrae Holdings Pty Ltd[2015] NSWSC 1416 Beech-Jones J at [46] reiterated the need for evidence of an actual pre-existing condition rather than a predisposition or susceptibility,“This reasoning is equally applicable to s 323 of the WIM Act. Thus to establish a pre-existing condition for the purposes of s 323(1) there must, at the relevant date, be an actual condition although it may be asymptomatic. A mere predisposition or even a susceptibility is not sufficient to constitute a condition.” (at 46).25.
In Vitaz v Westform (NSW) Pty Limited[2011] NSWCA 254 the Court said at paragraph 43,
“The resulting principle is that if a pre-existing condition is a contributing factor causing permanent impairment, a deduction is required even though the pre-existing condition had been asymptomatic prior to the injury. In the absence of any medical evidence establishing a contest as to whether the pre-existing condition did contribute to the level of impairment, the complaint about a failure to give reasons must fail. An approved medical specialist is entitled to reach conclusions, no doubt partly on an intuitive basis, and no reasons are required in circumstances where the alternative conclusion is not presented by the evidence and is not shown to be necessarily available.”
Cole v Wenaline Pty Ltd[2010] NSWSC 78 (Cole) is relevant authority for the principle that for a deduction to be properly made there must be evidence that a pre-existing abnormality; condition; or previous injury contributes to the impairment. In Fire & Rescue NSW v Clinen[2013] NSWSC 629 (Clinen), Campbell J refers to D’Aelo v Ambulance Service of New South Wales(1996) NSWCCR 139; Elcheikh v Diamond Formwork (NSW) Pty Ltd (in liq)[2013] NSWSC 365, and Cole.
In Clinen Campbell J said,“As Schmidt J pointed out in Cole and Elcheikh, it is necessary to find a pre-existing abnormality or condition, here the latter, actually contributing to the impairment before s. 323 WIM is engaged. This conclusion has to be supported by evidence to that effect. Assumption will not suffice.” Campbell J also noted that it is “...necessary for the evidence acceptable to the appeal panel to actually support the connection between a previous injury (here, pre-existing abnormality or condition) and the overall degree of impairment in the instant case.””
In the opinion of the panel the respondent suffers from the disease of osteoarthritis in her right knee. That disease was aggravated by her employment. The injury “consists in the aggravation, acceleration, exacerbation, or deterioration” of a disease within s 16 of the 1987 Act. While osteoarthritis was aggravated by the nature of her work, the evidence establishes that it commenced before the deemed date of injury, before the commencement of the employment that the respondent implicates in the aggravation of the disease, and, in all probability, before the commencement of her employment.
Osteoarthritis is a progressive condition. While it’s a course can be uneven, in this case it progressed to the point where the respondent worker required total knee replacement. While walking at work exacerbated or aggravated the condition, the underlying disease process is a powerful causative factor in bringing the applicant to knee replacement surgery. Absent the underlying disease process, the respondent would not have suffered an aggravation of the condition at work. Both factors contributed to the need for that surgery and to the whole person impairment. In the opinion of the panel these factors contributed equally to the respondent worker’s whole person impairment.
Accordingly, in the opinion of the panel, there should be a deduction of 1/2 pursuant to s 323(1) to reflect the contribution of the pre-existing osteoarthritis to the respondent’s impairment.
For these reasons, the Appeal Panel has determined that the MAC issued on should be revoked, and a new MAC should be issued. The new certificate is attached to this statement of reasons.
PERSONAL INJURY COMMISSION
APPEAL PANEL
MEDICAL ASSESSMENT CERTIFICATE
Injuries received after 1 January 2002
This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act 1998.
The Appeal Panel revokes the Medical Assessment Certificate of Dr Berryand issues this new Medical Assessment Certificate as to the matters set out in the Table below:
Table - Whole Person Impairment (WPI)
| Body Part or system | Date of Injury | Chapter, page and paragraph number in WorkCover Guides | Chapter, page, paragraph, figure and table numbers in AMA 5 Guides | % WPI | Proportion of permanent impairment due to pre-existing injury, abnormality or condition | Sub-total/s % WPI (after any deductions in column 6) |
| 1. Left Upper Extremity (knee) | 10/12/19 | Chapter 17 Page 549 Table 17-35 (Conversion-Table 17-33 on Page 547 | 15 | 15 | ||
| 2. Right Upper Extremity (knee) | 10/12/19 | Chapter 17 Page 549 Table 17-35 (Conversion-Table 17-33 on Page 547 | 20 | 1/2 | 10 | |
| Total % WPI (the Combined Table values of all sub-totals) | 24% | |||||
The above assessment is made in accordance with the Guidelines for the Evaluation of Permanent Impairment for injuries received after 1 January 2002
Paul Sweeney
Member
John Brian Stephenson
Medical Assessor
Thomassino Mastroianni
Medical Assessor
10 May 2022
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