DETERMINATION OF APPEAL PANEL	
	
CITATION:	Australian Plant Hire Pty Ltd v Al-Ameri [2024] NSWPICMP 575	
		
APPELLANT:	Australian Plant Hire Pty Ltd	
		
RESPONDENT:	Haydar Al-Ameri	
		
Appeal Panel		
		
MEMBER:	Rachel Homan	
		
MEDICAL ASSESSOR:	Alan Home	
		
MEDICAL ASSESSOR:	John Brian Stephenson	
		
DATE OF DECISION:	16 August 2024	
		
CATCHWORDS: 	wORKERS cOMPENSATION - Workplace Injury Management and Workers Compensation Act 1998 (1998 Act); whether demonstrable error or assessment on the basis of incorrect criteria in Medical Assessor’s determination that no deduction applied for pre-existing condition pursuant to section 323 of 1998 Act; where experts on both sides expressed opinion that a one-tenth deduction should apply for pre-existing but asymptomatic degenerative disease; Medical Assessor failed to engage with those opinions in making his own assessment; Held – demonstrable error found; Medical Appeal Panel not satisfied that any pre-existing condition or abnormality contributed to the impairment; Medical Assessment Certificate confirmed.

BACKGROUND TO THE APPLICATION TO APPEAL
1.	On 28 May 2024, Australian Plant Hire Pty Ltd [A.C.N. 092 021 059 Pty Ltd] (the appellant) lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr David Croker, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on 9 May 2024.
2.	The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (the 1998 Act): 
•	the assessment was made on the basis of incorrect criteria, and
•	the MAC contains a demonstrable error.
3.	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. 
4.	Rule 128 of the Personal Injury Commission Rules 2021 (the PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with r 128(1) of the PIC Rules.
5.	The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4th ed 
1 March 2021 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed (AMA 5). 
RELEVANT FACTUAL BACKGROUND
6.	The respondent, Mr Haydar Al-Ameri, who is currently 25 years old, sustained an injury to his right knee while driving a truck on 11 December 2019.  Several months after the injury, the respondent reported central low back pain, which he attributed to abnormal gait resulting from the right knee injury.
7.	The respondent made a claim for lump sum compensation pursuant to s 66 of the Workers Compensation At 1987 (the 1987 Act) on 15 December 2022, relying on an assessment of 13% whole person impairment (WPI) made by occupational physician, Dr Tommasino Mastroianni on 20 April 2022.
8.	Dr Mastroianni found 8% WPI of the right lower extremity (knee) and 5% WPI at the lumbar spine for the consequential condition. Dr Mastroianni made a one tenth deduction for pre-existing injury, condition or abnormality at the lumbar spine pursuant to s 323 of the 1998 Act.
9.	The claim was disputed by the appellant’s insurer on 9 March 2023 on the basis that the injury had not resulted in more than 10% permanent impairment as required by s 66(1) of the 1987 Act. The insurer relied on an assessment of 10% WPI made by orthopaedic surgeon, Dr Yuk Kai Lee on 31 January 2023.
10.	Dr Lee found 4% WPI at the right knee and 6% WPI at the lumbar spine. Dr Lee made no deductions under s 323 of the 1998 Act in his final calculations although earlier in his report, Dr Lee stated,
“I shall deduct one tenth of the impairment from the calculation as per Workcover protocol for Haydar’s right knee and back injury.”
11.	The respondent commenced proceedings in the Personal Injury Commission by lodgement of an Application to Resolve a Dispute on 22 March 2024. There being no liability dispute, the matter was referred to the Medical Assessor for determination of the medical dispute.
12.	The Medical Assessor examined the respondent on 29 April 2024 and issued the MAC on 
9 May 2024, in which he found that the injury on 11 December 2019 had resulted in a combined 11% WPI, comprising 4% WPI for the right knee and 7% WPI for the lumbar spine. No deduction pursuant to s 323 of the 1998 Act was made.
PRELIMINARY REVIEW
13.	The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7.
14.	As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination because there was sufficient material before the Appeal Panel to resolve the appeal.
EVIDENCE
Documentary evidence
15.	The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.  
Medical Assessment Certificate
16.	The Medical Assessor took a brief history of the injury, noting that on 11 December 2019, the respondent was operating a dump truck on uneven ground. When breaking with his right foot, the respondent heard a click associated with sharp pain to the region of the right knee. The respondent was walking with a limping gait. 
17.	The respondent was treated by his general practitioner and orthopaedic surgeon, Dr Arash Nabavi. The respondent underwent radiological investigations, and his knee was treated with PRP injections and physiotherapy, which he did not find helpful. The respondent did find hydrotherapy helpful.
18.	The respondent was also referred to Dr Matthew Lyons in relation to his right knee complaints.
19.	The respondent reported that a few months after the injury, he developed central low back pain, which he attributed to his abnormal gait. The respondent was referred for MRI examination of the lumbar spine, which was performed on 10 November 2020. 
20.	Neurosurgeon, Dr Balsam Darwish, saw the applicant on 21 January 2021. Dr Darwish advised continuation of conservative treatment. An injection procedure was arranged but provided little symptomatic benefit.
21.	The Medical Assessor noted that the respondent’s present treatment included Panadol Osteo or Nurofen Zavance as well as topical agents for pain relief. The respondent also used a knee guard and knee taping on an intermittent basis. The respondent had ceased physiotherapy and was under the care of his general practitioner.
22.	The respondent’s current symptoms included constant, variable central lower back pain of a moderate to strong degree. There was associated limited truncal range of motion. The respondent was also troubled by constant variable pain at the anterolateral aspect of the right knee extending to the infra patella region. There was limitation with active range of motion, a locking feeling, as well as intermittent swelling.
23.	The Medical Assessor recorded that there were no previous or subsequent accidents, injuries or conditions.
24.	The findings on examination were recorded and the Medical Assessor noted that he had reviewed copies of the multiple radiological reports contained in the referral documentation.
25.	The Medical Assessor relevantly summarised the injuries and diagnoses as follows:
“With respect to the region of the lumbar spine, radiological investigation has demonstrated changes consistent with an L5/S1 disc protrusion with potential nerve root compromise. 
It is considered that Mr Al-Ameri has suffered an aggravation of previously asymptomatic pre-existing early changes of the type described as a consequence of his employment.”
26.	In response to the question, “Is any proportion of loss of efficient use or impairment or whole person impairment, due to a previous injury, pre-existing condition or abnormality?”, the Medical Assessor said “no”.
27.	The Medical Assessor made an assessment of 11% WPI, noting that he had taken into account the history, physical examination and referral documentation in making the assessment. The Medical Assessor explained his calculations and commented:
“It is considered that there is nil evidence of a pre-existing injury or medical condition that needs to be taken into account by way of contributory impairment that would justify any deductions.”
28.	The Medical Assessor referred to the report of Dr Mastroianni and noted his 1/10 deduction with respect to the lumbar spine. The Medical Assessor also referred to the report from 
Dr Lee.
29.	Under the heading, “Deduction (if any) for the proportion of the impairment that is due to previous injury or pre-existing condition or abnormality”, the Medical Assessor repeated,
“It has been indicated that it is my opinion that there is nil evidence of a pre-existing injury or condition that needs to be taken into account by way of contributory impairment that would justify any deductions.”
SUBMISSIONS 
30.	Both parties made written submissions. They are not repeated in full but have been considered by the Appeal Panel. 
31.	In summary, the appellant submits that the Medical Assessor failed to consider and apply the relevant principles in determining that a deduction for the respondent’s pre-existing lumbar disc disease at L5/S1 did not apply.
32.	The appellant submitted that Medical Assessor confirmed that radiological investigations of the respondent’s lumbar spine revealed changes consistent with an L5/S1 disc protrusion with potential nerve root compromise. The Medical Assessor characterised the injury as an aggravation of previously asymptomatic pre-existing early changes of the type described as a consequence of his employment.
33.	Referring to the decisions in Cole v Wenaline Pty Ltd [2010] NSWSC 78, Vitaz v Westform (NSW) Pty Limited [2011] NSWCA 254 and Ryder v Sundance Bakehouse [2015] NSWSC 526, the Medical Assessor failed to consider whether the pre-existing pathology at L5/S1 caused or contributed to the respondent’s impairment.
34.	In addition, referring to the decisions in Wingfoot Australia Partners Pty Ltd v Kocak [2013] HCA 43 and State of New South Wales (NSW Department of Education) v Kaur [2016] NSWSC 346, the appellant submitted that Medical Assessor failed to provide sufficient reasoning as to why he did not agree with the opinions given by both parties’ medicolegal experts, that a deduction under s 323 of the 1998 Act was warranted.
35.	The respondent agreed with the legal principles identified by the appellant but submitted that the Medical Assessor did in fact consider whether the pre-existing pathology at L5/S1 was a contributing factor to the presenting impairment. Having considered if the pre-existing pathology contributed to or caused the impairment, the Medical Assessor concluded that it did not so contribute and as such no deduction was required under s 323 of the 1998 Act.
36.	The respondent relied on the references to a pre-existing condition in the MAC and the Medical Assessor’s conclusion that there was nil evidence of a pre-existing injury or condition that needed to be taken into account by way of “contributory impairment that would justify any deductions”.
37.	The respondent further submitted that the path of reasoning in the MAC was sufficient to enable a determination as to whether or not an error of law has occurred, despite the fact that there was no express rebuttal of the reports of Drs Mastroianni and Lee regarding the contribution of the pre-existing pathology.
38.	The respondent submitted that that the function of the Medical Assessor was not to adjudicate between the reports of the parties; rather, the Medical Assessor was required to apply his own medical experience and expertise in providing an opinion, which had occurred in this instance to the requisite level of detail.
FINDINGS AND REASONS 
39.	The procedures on appeal are contained in s 328 of the 1998 Act. The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made. 
40.	In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
41.	The Appeal Panel has considered the respondent’s written statement dated 3 March 2024. The respondent stated that prior to the injury he was very active, played soccer, went camping, swam, enjoyed quad biking and travelling. The respondent looked after the garden and lawns and helped with house work. While studying architecture at university, the respondent did casual work in labouring and traffic control for the appellant.
42.	The respondent said he had no prior workers compensation claims and no previous injuries to his back or right knee. 
43.	The respondent described the injury and subsequent treatment. The respondent said he noticed an onset of lower back pain in or around November 2020 and was referred for an MRI scan of his lower back.
44.	The reports of two MRI examinations are in evidence. The report of an MRI of the lumbar spine performed on 10 November 2020 records that there was a small left paracentral disc protrusion at L5/S1 partly extending to the neural foramen.
45.	The report of a second MRI performed on 27 September 2021 noted desiccation and mild narrowing of the L5/S1 disc. There was no disc bulge or disc protrusion.
46.	In his report dated 20 April 2022, Dr Mastroianni described the condition at the respondent’s lumbar spine as follows,
“He subsequently developed back pain as a result of the abnormal gait and favouring of the right leg. He has aggravated and precipitated symptoms of underlying constitutional lumbosacral disc disease as a result of the limp.”
47.	Dr Mastroianni went on to note,
“MRI reveals disc pathology at the L5-S1 lesion however there was no work injury causing the lesion and I consider the disc lesion to be constitutional aggravated by limping caused by the knee injury.”
48.	Dr Mastroianni concluded that the altered posture as the respondent walked caused stress on the lumbosacral segment aggravating the underlying disc lesion causing pain.
49.	In his report for the insurer, Dr Lee also noted that the applicant had no relevant past medical history. Dr Lee described the injury and subsequent treatment noting that there was no frank injury to the back. Dr Lee diagnosed a minor L5/S1 disc injury caused by limping.
50.	Asked to comment on whether any proportion of permanent impairment resulting from pre-existing injury conditional abnormality, Dr Lee stated,
“The MRI report also showed disc degeneration of the L5/S1 disc, which is most likely pre-existing but asymptomatic prior to injury. I shall deduct 1/10 of the impairment from the calculation as per the WorkCover protocol.”
51.	Dr Lee said he agreed with Dr Mastroianni’s assessment of the lumbar spine but said there should also be a deduction for pre-existing condition at the knee. In his final calculations, however, no deduction was made.
52.	The Medical Assessor  acknowledged the reports of Dr Mastroianni and Dr Lee in the MAC, including the one tenth deduction made by Dr Mastroianni, however, he did not engage with their comments that the pathology seen on the MRI scans most likely pre-dated the injury and therefore warranted a deduction under s 323 of the 1998 Act. The Medical Assessor neither referred to those opinions nor explained why he disagreed with them.
53.	The experts’ views as to the nature of the pathology seen on radiological examination and its contribution to the respondent’s permanent impairment was relevant material that had potential to alter the outcome of the assessment and potentially the entitlement to lump sum compensation under s 66 of the 1987 Act.  
54.	In the Appeal Panel’s view, the MAC does not demonstrate that the Medical Assessor properly considered this aspect of the parties’ expert opinions. As a result, a demonstrable error is established. 
55.	In Tasevski v Westpac Banking Corporation [2024] NSWSC 41, Schmidt AJ, referring to the High Court decision in Vannini v Worldwide Demolitions Pty Ltd, discussed the meaning of “demonstrable error”: 
“Gleeson JA explained that ‘demonstrable error’, a term which is not defined, is intended to convey the degree of strictness of scrutiny to which the disputed assessment may be subjected. As such, a finding of ‘error alone is not sufficient’. The error must be ‘material’ and apparent in the certificate, although there is no limit on the material to which the Panel may have regard when assessing whether the certificate ‘contains’ a demonstrable error: at [77]-[78].
An error is also not demonstrable merely because the Panel disagrees with the assessor’s opinion: at [87]. An error for which there is no information or material to support the finding made, rather than a difference of opinion, will establish a demonstrable error.”
56.	Having found that the MAC was affected by demonstrable error, the Appeal Panel has considered for itself whether a deduction ought to be made pursuant to s 323 of the 1998 Act.  Section 323 of the 1998 Act relevantly states:
“(1)	In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality.”
57.	To make a deduction for the purposes of s 323 of the 1998 Act, it is necessary to establish that there was a pre-existing medical condition that has contributed to the assessable impairment.
58.	In Cole v Wenaline Pty Limited [2010] NSWSC 78 Schmidt J said:
“...The section is directed to a situation where there is a pre-existing injury, pre-existing condition or abnormality. For a deduction to be made from what has been assessed to have been the level of impairment which resulted from the later injury in question, a conclusion is required, on the evidence, that the pre-existing injury, pre-existing condition or abnormality caused or contributed to that impairment.”
59.	The Appeal Panel is not satisfied that any pre-existing injury, medical condition or abnormality contributed to the assessable impairment.
60.	The Appeal Panel notes that the respondent had no prior history of low back pain or low back injury. The evidence consistently indicates that his back pain commenced in the absence of discrete trauma, due the altered gait which resulted from the right knee injury.
61.	The post-injury MRI scans of 10 November 2020, taken 11 months after the knee injury demonstrated an isolated small left paracentral disc protrusion. 
62.	There was no recorded underlying developmental or degenerative change in the affected or adjacent intervertebral disc or the adjacent facet joints.
63.	By 27 September 2021, the disc protrusion was no longer reported. It had therefore shrunk or resorbed. Whilst drying out (desiccation of the disc) is recorded in the second MRI scans, this is clearly documented to have occurred after the workplace injury.
64.	The Appeal Panel finds that there is a lack of clarity in the findings of the Medical Assessor and Dr Lee. The Medical Assessor detailed a diagnosis of an L5/S1 disc protrusion based on the radiological findings. However, he then added:
“…it is considered that Mr Al-Ameri has suffered an aggravation of a previously asymptomatic pre-existing change of the type described as a consequence of his employment.”
65.	When asked whether any proportion of the impairment found was due to a previous injury, pre-existing condition or abnormality, the Medical Assessor simply responded “no”.
66.	Similarly, Dr Lee found that the limping caused a minor disc injury at L5/S1. Elsewhere in his report, however, he agreed that there was likely pre-existing but asymptomatic disc degeneration at that level. When calculating permanent impairment, Dr Lee made no deductions.
67.	The Appeal Panel notes that the Medical Assessor’s and Dr Lee’s comments regarding pre-existing but asymptomatic disc degeneration are consistent with the opinion expressed by Dr Mastroianni. 
68.	While the Appeal Panel agrees with the diagnosis of a L5/S1 disc protrusion resulting from limping, the Appeal Panel is not satisfied that the disc protrusion was pre-existing or that there was any pre-existing disc disease. The Appeal Panel considers it more probable than not that the disc lesion at L5/S1 resulted from the limping and therefore the injury.
69.	The Appeal Panel reaches this conclusion on the basis that:
(a)	there is no record of pre-existing back pain or injury;
(b)	there is no radiological evidence of a disc protrusion or other underlying condition preceding the onset of the respondent’s symptoms;
(c)	there is no evidence of any developmental abnormality to account for the pathology;
(d)	there is a discrete pathological change at L5/S1 with no degenerative changes seen at that segment or in any of the adjacent segments, and
(e)	pre-existing degenerative changes of this nature are most unlikely at the age of 21 (the age at the time of the first imaging).
70.	The Appeal Panel considers that the mechanism of the respondent’s documented limping or altered gait was sufficient to have caused the pathology identified on the radiological investigations.
71.	As a result, the Appeal Panel finds there was no pre-existing condition or abnormality contributing to the impairment and agrees with Dr Crocker’s ultimate statement:
“…there is nil evidence of a pre-existing injury or medical condition that needs to be taken into account by way of contributory impairment that would justify any deductions.”
72.	For these reasons, the Appeal Panel has determined that the MAC issued on 9 May 2024 should be confirmed.