DETERMINATION OF APPEAL PANEL	
	
CITATION:	Pateman v Secretary, Department of Education [2024] NSWPICMP 776	
		
APPELLANT:	Michelle Pateman	
		
RESPONDENT:	Secretary, Department of Education	
		
Appeal Panel		
		
MEMBER:	Marshal Douglas	
		
MEDICAL ASSESSOR:	Roger Pillemer	
		
MEDICAL ASSESSOR:	Gregory McGroder	
		
DATE OF DECISION:	20 November 2024	
		
CATCHWORDS: 	wORKERS cOMPENSATION - Workplace Injury Management and Workers Compensation Act 1998; whether the Medical Assessor (MA) correctly assessed the appellant’s impairment relating to her sacroiliac joint; whether MA erred by not assuming in accordance with section 323(2) that the deduction to be made under section 323(1) for the proportion of the appellant’s permanent impairment that is due to a per-existing condition is 10%; whether MA erred by not adequately explaining the deduction he made; Held – MA made no error; Medical Assessment Certificate confirmed.

BACKGROUND TO THE APPLICATION TO APPEAL
1.	On 11 September 2024 Michelle Pateman, the appellant, lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Yiu-Key Ho, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on 
3 September 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 (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 ground(s) of appeal on which the appeal is made. 
4.	Rule 128 of the Personal Injury Commission Rules 2021 (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 appellant is employed as a primary school teacher with the NSW Department of Education.  In accordance with s 26(1) and Part 1 of Schedule 1 of the Government Sector Employment Act 2013, the Secretary of that Department is the employer of the appellant and the respondent to this appeal.  
7.	On 27 February 2020 the appellant was working at the Flinders Public School.  On that day, after exiting the staff room, she slipped on a water bottle causing her to injure her lower back.  She attended her general practitioner around a week after and he arranged for physiotherapy and also an MRI scan of the appellant’s lower spine, which was done on 4 March 2021.  
8.	Following that investigation her general practitioner referred her to orthopaedic surgeon 
Dr Tom Pitham. Dr Pitham had previously on 17 August 2019 undertaken a right L5/S1 microdiscectomy and S1 rhizolysis on the appellant to treat a right sided radiculopathy with foot drop that the appellant was then suffering.  The summary that was issued for that procedure noted that Dr Pitham had identified “a large central disc sequestrum, that was displacing the appellant’s right S1 nerve root”.  Dr Pitham further noted that that sequestrum “was excised in a series of large pieces, with good compression of both the central canal and the exiting S1 nerve root achieved”.
9.	In a statement the appellant signed on 6 June 2024 she said she had an excellent result from her discectomy and so long as she was mindful of her limitations her back was pain free.  She said was able to go back to her activities including park running.  
10.	It seems from the evidence before the Appeal Panel that following the appellant injuring her lumbar spine on 27 February 2020, Dr Pitham first saw her on 9 November 2020.  In a report Dr Pitham wrote to the appellant’s general practitioner on that date he noted that the appellant had made an excellent recovery from her prior surgery “with complete resolution of her pain, and only a small amount of residual numbness which did not respond to surgery”.  Dr Pitham also advised that he reviewed the appellant’s most recent MRI which he said revealed “a moderate sized disc recurrence at the L5/S1 level”.  The scan to which Dr Pitham refers would seem to be the MRI scan of the appellant’s lumbar spine done on 4 March 2021 which also revealed that at that level the appellant had disc desiccation.  
11.	Dr Pitham also advised in his report of 9 November 2020 that he would organise further investigations and physiotherapy for the appellant.  He again organised additional investigations when he reviewed her on 14 May 2021.  
12.	He again reviewed her on 2 August 2021 and in a letter to the appellant’s general practitioner on that date he advised that the appellant had an S1 joint injection on her right side a few weeks before this consultation that resulted in complete resolution of her pain for three to four weeks which he said confirmed “the diagnosis of SI joint dysfunction”.  He advised that he would request permission for the appellant to undergo a right sacroiliac joint fusion.  It is apparent that he would be seeking that permission from the respondent’s insurer.  He ultimately received its permission and undertook the surgery on 14 September 2021.  
13.	Dr Pitham reviewed the appellant several times after that surgery, including on 
11 February 2022.  In his report to the general practitioner regarding that consultation he noted that the appellant had “been complaining of brief episodes of sudden pain in her lumbar spine”.  Dr Pitham advised the general practitioner that he had shown the appellant her most recent CT scan that revealed significant disc disease of the L5/S1 disc including marginal osteophytes that he considered was the likely cause of her pain.  He said that he “reassured” the appellant that that was “a completely normal part of getting older”.
14.	Dr Pitham again reviewed the appellant on 22 August 2022 and in his report to the general practitioner on that consultation noted the appellant was experiencing “pain as spasms” which the appellant had described as “severe enough sometimes to make her feel as if she is being kicked in the back”.  Dr Pitham noted that he had organised a CT scan and an MRI scan, and he advised that the MRI scan revealed a lumbar spine with L5/S1 degeneration which Dr Pitham opined was “almost certainly the cause of ongoing pain”.  He advised her general practitioner that “unfortunately, like so many people, her back is fairly worn out at the L5/S1 level”.
15.	On 14 December 2023 the appellant’s solicitors wrote to the respondent’s insurer advising it the appellant claimed compensation from it for permanent impairment from her injury, which they advised was of the order of 14% whole person impairment (WPI).  It advised that the appellant relied on a report of Dr Anil Nair dated 31 August 2023 to support her claim and provided the insurer with a copy of Dr Nair’s report.  
16.	Dr Nair, who the Appeal Panel notes is an orthopaedic surgeon, advised in his report that the appellant was “largely asymptomatic” after the lumbar decompression surgery Dr Pitham had performed on 17 August 2019.  He advised the appellant had suffered “a right sacroiliac joint injury” due to the incident on 27 February 2020 and had “a permanent aggravation of a pre-existing lumbar spondylosis”.  He advised he assessed the appellant had 14% WPI from her injury, which was a combination of 8% WPI he assessed the appellant had relating to her right sacroiliac joint and 6% WPI he assessed she had relating to her lumbar spine.  He advised his assessment relating to the appellant’s right sacroiliac joint was made by reference to the criteria of Table 4.3 of the Guidelines on the basis that the appellant had “a maximum displacement of less than 1 centimetre”.  He also advised he assessed the appellant’s permanent impairment relating to her lumbar spine was done by reference to Table 15-3 of AMA5.  He considered that due to the appellant having dysmetria she correlated with the criteria for DRE lumbar category II, within that Table, which provides for a base assessment of 5% WPI and to which he added 2% WPI due to the restrictions the appellant had relating to activities of daily living.  He noted that resulted 7% WPI but said that “due to the fact that she has had a pre-existing lumbar injury and surgery a 1/10th deduction is appropriate”.  
17.	Hence his assessment that the appellant had 14% WPI from her injury.  
18.	The respondent’s insurer organised for the appellant to be examined orthopaedic surgeon 
Dr Robin Diebold on 6 March 2024.  In a report of that date Dr Diebold noted that the appellant had “immediate resolution of symptoms” following her surgery on 17 August 2019.  Dr Diebold also advised in his report that he assessed the appellant had 6% WPI relating to her lumbar spine from her injury.  He too assessed the appellant’s injury by reference to DRE category II on the basis that the appellant showed significant lumbar guarding.  He also added 2% WPI to the base of 5% WPI allowed under DRE category II.  He too considered a deduction of 1/10th was also appropriate because of “previous lower back injury and surgery”.
19.	Dr Diebold advised that he assessed the appellant had 0% WPI relating to her right sacroiliac joint. This was because he considered a scan done on 17 December 2020 revealed a normal right sacroiliac joint.  He said that because of that he was “unable to find that there has been a former fracture or dislocation of the right sacroiliac joint”.  He indicated that his assessment was also done by reference to Table 4.3 of the Guidelines.
20.	The Appeal Panel notes that Dr Diebold’s reference to a CT scan done on 
17 December 2020 contains a typographical error in that the CT scan was in fact done on 
17 December 2021.  The finding from that scan relating to the appellant’s right sacroiliac joint is as follows:
“Right sacroiliac joint fusion with two i Fuse devices.  The right sacroiliac joint line appears ? minimally more narrowed compared to the left although there is no solid bony fusion.
Left sacroiliac appears unremarkable.”
21.	On 16 May 2024 the insurer wrote to the appellant notifying her under s 78 of the 1998 Act that it disputed she was entitled to compensation for permanent impairment from her injury.  The reasons it provided her for its decision were, in substance, that it relied on the assessment Dr Diebold had done of her permanent impairment from her injury which was 6% WPI and which did not exceed the threshold imposed by s 66 of the Workers Compensation Act 1987 for her to be entitled to compensation for permanent impairment from her injury.
22.	A medical dispute consequently arose between the parties regarding the degree of permanent impairment the appellant had from her injury which precipitated the appellant filing with the Personal Injury Commission (Commission) an Application to Resolve a Dispute dated 13 June 2024, by which she sought determination of her claim for permanent impairment.  
23.	The matter was referred to the Medical Assessor, who examined the appellant on 
29 August 2024 and, as said above, issued the MAC on 3 September 2024.  In that he certified he assessed the degree of the appellant’s permanent impairment from her injury was 9%.  That was a combination of 5% WPI relating to her sacroiliac joint and 4% WPI relating to her lumbar spine.  With respect to his assessment of the appellant’s impairment relating to her lumbar spine he assessed the appellant had an overall permanent impairment of 7% but he made a deduction of 50% (1/2) under s 323(1) of the 1998 Act for a proportion of the appellant’s permanent impairment that he considered was due to a pre-existing condition.  
24.	The issues the appellant has raised in her appeal against the medical assessment involve the Medical Assessor’s assessment of her permanent impairment relating to her sacroiliac joint and the deduction the Medical Assessor made under s 323(1) when assessing the permanent impairment she had relating to her lumbar spine.
25.	Relevant to those matters, the Medical Assessor noted that the appellant had a right sacroiliac joint fusion done by Dr Pitham which the Medical Assessor noted had helped the appellant but did not result in a complete resolution of the appellant’s symptoms.  The Medical Assessor also explained that he assessed the appellant’s impairment relating to her sacroiliac joint by reference to Table 4.3 of the Guidelines and said that “with a fusion that will be a 5% whole person impairment”.  He noted that Dr Nair had assessed the appellant had 8% WPI relating to her sacroiliac joint, about which the Medical Assessor commented would require there to be a “displacement after fracture”.  The Medical Assessor said that the appellant’s situation is that she has a fusion which he considered equated with an “ankyloses” under Table 14.3 for which the rating is 5% WPI. 
26.	The Medical Assessor also noted that Dr Diebold assessed the appellant had 0% WPI for the sacroiliac joint in regard to which the Medical Assessor said he cannot agree because the appellant had surgery done on her sacroiliac joint to fuse the joint, which is not “an intact or normal SI joint”.
27.	Relating to the deduction the Medical Assessor made when assessing the appellant’s permanent impairment due to her lumbar spine, the Medical Assessor noted within the history he obtained that the appellant had previously had a discectomy at the L5/S1 level for  right sciatica that she had experienced in 2019 with significant neurological problems.  The Medical Assessor noted that the appellant had “a quick and good recovery from that”.
28.	The Medical Assessor noted that the appellant’s fall, and consequently injury, on 
27 February 2020 was on the background of her having an L5/S1 discectomy for right sciatica a year previously. 
29.	The Medical Assessor recorded that the appellant complained to him of pain that was not confined to her right sacroiliac joint but also included tenderness on her left side with stiffness of her back.  He noted that the appellant could only sit to drive for 20 minutes and that she could not pick anything up off the floor and could not bend down or sit for very long.  The Medical Assessor noted that the appellant did not experience pain radiating down below her buttock.  The Medical Assessor noted that the appellant could not do anything physical at her home because of her stiff and sore back.
30.	The Medical Assessor found from his examination of the appellant that the appellant had muscle spasm and restricted movement of her back in forward flexion such that the appellant could only touch her knee joint.  The Medical Assessor found that the appellant also had restriction of movement in all other planes to about 50% of normal.  The Medical Assessor found the appellant had straight leg raising to 80 degrees on both sides, no tension signs of the sciatic nerve, no neurology in the lower limbs with respect to her motor power, sensation and reflex jerks, and no tenderness on palpation or stressing on both sacroiliac joints.
31.	Ther Medical Assessor also noted that an MRI scan of the appellant’s lumbosacral spine done on 4 March 2021 revealed no pathology other than a pre-existing L5/S1 discectomy on the right side.  
32.	The Medical Assessor provided the following explanation at part 10b of the MAC for the assessment he made of the appellant’s permanent impairment relating to her lumbar spine:
“To assess the whole person impairment for the back pain using AMA Guide 5th Edition Table 15-3 this is a case of DRE lumbar category 2, she demonstrates muscle spasm, loss of movement but without neurology for radiculopathy. This will be a lumbar category 2 with 5% whole person impairment. For assessment of activities of daily living using WorkCover Guide 4th Edition page 28 section 4.34 she will have 2% for difficulty with activities of daily living because she can look after herself but difficulty with all sorts of physical activities altogether there is 7% whole person impairment. I believe a ½ deduction is appropriate as patient just had a discectomy less than a year ago and that will leave behind a 4% whole person impairment for this injury.”
33.	The Medical Assessor noted that both Dr Nair and Dr Diebold had when assessing the appellant’s permanent impairment relating to her lumbar spine, deducted 1/10th for the contribution of pre-existing conditions.  The Medical Assessor said the following with respect to that:
“I think it should be more because the surgery before this work injury was less than a year and I think the residual back pain from this particular injury is a problem of the L5 S1 level, whether that is from the disc which had discectomy before or the” associated facet joint. I realise SI joint fusion has been done on the right side but I still believe the main problem is referred from the L5 S1 level and with a history of operation just within a year before this particular injury a deduction of ½ is appropriate.”
PRELIMINARY REVIEW
34.	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.
35.	As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the appellant to undergo a further medical examination.  This is because the Appeal Panel found that none of the grounds for appeal on which the appellant relied were substantiated, and accordingly there was no need to examine the appellant. 
EVIDENCE
36.	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.  
SUBMISSIONS 
37.	Both parties made written submissions. They are not repeated in full, but have been considered by the Appeal Panel. 
38.	Paraphrasing the appellant’s submissions, to provide a summary of them, they are that the Medical Assessor did not deal with the reasoning of Dr Nair with respect to his assessment of her permanent impairment relating to her sacroiliac joint which was she had 8% WPI due to “a maximum displacement of less than 1 centimetre”.  
39.	The appellant referred to a report on a CT scan done on 17 December 2021.  The appellant contended the scan revealed a change in her sacroiliac joint because the report on the scan was that her right sacroiliac joint line appeared “minimally more narrowed compared with the left”.  
40.	The appellant also referred to a CT scan of her lumbar spine done on 10 August 2022 which revealed high density coils in the left gonadal vein, generalised osteopenia, a small intraosseous haemangioma, and a normal left S1 joint and pubic symphysis.  The appellant submitted that these findings 11 months after surgery demonstrated change in her right sided sacroiliac joint had occurred.  She submitted that the osteopenia indicated loss of bone mass and that, as a consequence, the assessment Dr Nair made is appropriate.
41.	With respect to the Medical Assessor’s assessment of her impairment in her lumbar spine, the appellant noted that the Medical Assessor had said he believed “a half deduction is appropriate as patient just had a discectomy less than a year ago”.  The appellant submitted that is incorrect and that the discectomy happened on 17 August 2019.  The appellant highlighted that was more than one year before the Medical Assessor assessed her impairment from her injury.
42.	The appellant submitted that the Medical Assessor provided no reasoning regarding why he made a deduction of a half for a pre-existing condition and simply stated that she had a discectomy.  
43.	The appellant noted that both Dr Nair and Dr Diebold only made a deduction of 1/10th for a pre-existing condition.  The appellant submitted that the Medical Assessor did not adequately explain why his opinion relating to the deduction to be made differed from the opinions of 
Drs Nair and Diebold.  The appellant submitted, noting that her discectomy occurred five years before the Medical Assessor assessed her impairment, that the Medical Assessor did not explain why that procedure warranted a 50% deduction for a pre-existing condition.
44.	The appellant referred to parts of her statement wherein she said she had an excellent result from her discectomy and that her pain was much improved following her surgery, although it never totally resolved.  The appellant submitted that the Medical Assessor failed to consider that evidence and failed to make appropriate enquiry of her regarding her back condition prior to her injury.  
45.	The appellant submitted that the Medical Assessor ought to have assumed in accordance with s 323(2) that the deduction to be made under s 323(1) was 10%.  The appellant submitted that the Medical Assessor failed to identify any medical evidence that would make that assumption wrong.  
46.	Paraphrasing the respondent’s submissions, again to provide a summary of them, they are that the Medical Assessor did not err by assessing the appellant’s permanent impairment relating to her sacroiliac joint is 5% WPI and the Medical Assessor correctly made that assessment in accordance with section 4 of Table 4.3 of the Guidelines.  The respondent submitted that the Medical Assessor based his assessment on his clinical examination of the appellant and his interpretation of the clinical material.
47.	The respondent submitted that the Medical Assessor’s reference to the appellant having a discectomy less than a year ago was a reference to her having a discectomy less than a year before her date of injury. The respondent submitted that is clear from the history the Medical Assessor detailed in the MAC wherein he noted that the appellant’s injury occurred on 
27 February 2020 and her discectomy of the right L5/S1 occurred in 2019.  
48.	The respondent submitted that the Medical Assessor considered the appellant’s pre-existing history including this discectomy was significant and that the Medical Assessor “was not obligated to go into significant detail into why he believed a higher deduction was warranted, nor was he impelled to give weight to the applicant’s statement”.  
49.	The respondent submitted that the Medical Assessor did not fall into error with the deduction he made.
FINDINGS AND REASONS 
50.	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. 
51.	In Campbelltown City Council v Vegan [2006] NSWCA 284 the Court of Appeal held that the Appeal Panel is obliged to give reasons. 
Sacroiliac joint
52.	The Medical Assessor was correct to apply the criteria set out in Table 4.3 of the Guidelines to assess the degree of the appellant’s impairment relating to her sacroiliac joint.  Section 4 of that table provides the following relevant criteria:
Sacro-Iliac joint dislocations or fracture dislocations 	WPI (%)	
i. maximum residual displacement <1cm 	8 	
ii. maximum residual displacement >1cm 	12 	
iii. internal fixation/ankylosis 	5 	
53.	The Medical Assessor was correct, in the Appeal Panel’s view, to rate the appellant’s impairment relating to her sacroiliac joint based on item iii and this is because the sacroiliac joint fusion the appellant had on 9 September 2021, the consequence of which was that she had a sacroiliac joint that fixed and could not move.  There was accordingly no displacement of her sacroiliac joint.  There was consequently no basis to rate her impairment by reference to item i, as Dr Nair had done.  
54.	In the Appeal Panel’s view, the Medical Assessor sufficiently explained this in the MAC in that he said the rating that Dr Nair had assigned meant that there would have to be displacement after the fracture.  The Medical Assessor considered there was not because of the fusion of the sacroiliac joint that Dr Pitham had done.  The Medical Assessor said that this was the equivalent of ankylosis of the sacroiliac joint.  The Appeal Panel agrees with that.  
55.	The Appeal Panel notes that the CT scan that was done on 17 December 2021, which confirmed the fusion of the right sacroiliac joint with two iFuse devices, reported that the sacroiliac joint appeared minimally more narrow compared to the left. This however, is not a finding that there is displacement of the sacroiliac joint.  Further the fact that the appellant may have osteopenia in her sacroiliac joint does not indicate or mean there is any displacement that would allow a rating to be made by reference to item i within s 4 of Table 4.3.
Section 323
56.	The Appeal Panel does not accept the appellant’s submission to the effect that the Medical Assessor misunderstood her surgery occurred less than a year before he conducted his assessment of her permanent impairment.  This is apparent from the history the Medical Assessor took wherein he noted that the appellant’s L5/S1 surgery was done less than a year prior to her suffering injury on 27 February 2020.  The Medical Assessor also noted in part 10c of the MAC, when comparing his assessment with the assessments of Dr Nair and Dr Diebold, that the appellant’s surgery at L5/S1 was less than a year before her work injury.  It is apparent from this that when the Medical Assessor said in parts 10b and 11i of the MAC that the appellant had a discectomy less than a year ago, his meaning was within a year of the appellant suffering injury and not within a year from his assessment. 
57.	There is no challenge to the Medical Assessor’s conclusion that a proportion of the appellant’s permanent impairment from her injury is due to a pre-existing condition.  The appellant contends however that the Medical Assessor erred by concluding that the proportion was 50% because such a conclusion does not accord with the evidence.  
58.	Further, the appellant contends that in accordance with s 323(2) of the 1998 Act the Medical Assessor was required to assume the proportion of her permanent impairment from her work injury that is due to her pre-existing condition is 10%.  This is because it would be difficult or costly to determine what the deduction is and because making that assumption is not at odds with the available evidence, which includes what she said at paragraphs 15 and 16 of her statement and also the opinions of Dr Nair and Dr Diebold.  
59.	The appellant also contends that the Medical Assessor did not provide adequate reasons to explain his conclusion that 50% of her permanent impairment from her work injury is due to her pre-existing condition and that, as a consequence of his inadequate reasons, the MAC also contains a demonstrable error.
60.	The appellant’s discectomy at L5/S1 and S1 rhizolysis occurred on 14 September 2019, which is around five months before she suffered her injury on 27 February 2020.  In her statement she said at paragraph 15 that the surgery she had on 14 September 2019 provided her an excellent result with respect to her back.  She said similarly at paragraph 28 of her statement.  At paragraph 15 she also said that “so long as I was careful and mindful of my limitations my back was pain free”.
61.	Dr Pitham in his report of 9 November 2020 to the appellant’s general practitioner also noted that the appellant had made an excellent recovery from the surgery on 9 September 2019. He said she had a complete resolution of pain although with a small amount of residual numbness that followed the S1 distribution.  In the summary that was prepared for the surgery the appellant had on 14 September 2019, Dr Pitham noted that a large disc sequestrum was removed at the appellant’s L5/S1.
62.	The MRI scan done on 4 March 2021 was reported to reveal disc desiccation and disc space narrowing at the L5/S1 with a broad base disc bulge.  A subsequent MRI done on 
2 August 2022 was reported to reveal mild bilateral facet joint degenerative change at the L5/S1 as well as a small disc protrusion.  A CT scan done on 10 August 2022 revealed mild disc space narrowing at the L5/S1 with broad base posterior disc osteophyte complex, mild facet spondylosis and mild bilateral F5 foraminal narrowing.
63.	The Medical Assessor assessed the degree of the appellant’s impairment relating to her lumbar spine based on the appellant exhibiting during his examination of her muscle spasm and loss of movement without neurology for radiculopathy.  Those signs correlate with the criteria for DRE lumbar category II in Table 15-3 of AMA5.  
64.	Within part 10c of the MAC the Medical Assessor explained that the appellant’s back pain is due to her L5/S1 disc or the associated facet joint. The Appeal Panel notes that the proximate cause of the appellant’s back pain would in all likelihood be due to her muscle spasms, the source of which is, as the Medical Assessor identified her L5/S1 disc or associated facet joint.
65.	It is apparent to the Appeal Panel from that explanation, that the Medical Assessor concluded that his assuming that the proportion of the appellant’s degree of permanent impairment from her injury, insofar as it relates to her lumbar spine, that is due to her pre-existing condition is 10% would be at odds with the evidence, that evidence being the condition of the appellant’s L5/S1 disc. It is the condition of the appellant’s L5/S1 disc that causes the back pain she suffers, which pain, as the Appeal Panel has said, results from her muscle spasm consequent upon the condition of her L5/S1 pathology.
66.	The Appeal Panel notes that a Medical Assessor is required in accordance with s 325(2) of the 1998 Act to set out his or her reasons for the assessment made and to set out the facts upon which the assessment is based. That obligation requires a Medical Assessor to reveal the reasons by which he or she arrived at the assessment in sufficient detail such that it can be ascertained whether there is any error in their reasoning. The reasons do not necessarily need to be comprehensible to a person with no medical expertise. In a circumstance where an assessment or conclusion of a Medical Assessor would be self-evident to a medical practitioner and there is no medical contest regarding it, a Medical Assessor can shortly state his or her reasons. If, however, a conclusion is medically contestable or controversial a more extensive explanation will be required. 
67.	The proportion of the appellant’s pre-existing condition to her permanent impairment from her injury is a medical contestable issue.  This is apparent from the fact that the Medical Assessor came to a different view regarding this matter than both Dr Diebold and Dr Nair.  In that circumstance, the Appeal Panel considers that the Medical Assessor was required to provide a more extensive explanation than what he did for making a deduction of 50% under s 323(1) of the 1998 Act.  Given it was a medically contestable issue he ought to have explained better by reference to the evidence that was before him why he considered a deduction of 50% was made.  Insofar as he did not do that, he made an error such that the MAC contains a demonstrable error.
68.	However, in the Appeal Panel’s view the deduction the Medical Assessor made of 50% is correct.  This is because at the time of injury the appellant had a damaged disc.  That is evident from the radiological investigations that were done after her injury, which revealed degeneration at L5/S.  Further, although in her statement she had an excellent result from the surgery, she nevertheless still had to take care and be mindful of her back to ensure she experienced no pain.  In other words, she did have limitations with her, which, if she was not careful, could generate symptoms in her back.  That is consistent with her having a damaged disc at L5/S1.
69.	The surgery the appellant had on her L5/S1 on 14 September 2019 removed a large part of her disc.  The radiological investigations done thereafter revealed degeneration at that disc.  That degeneration, noting that these investigations were done 1 year to 18 months after her injury, could not have occurred as a consequence of her injury.  They were existing at the time of her injury, and were likely due to her age, that is a constitutional issue, coupled with the surgery on 14 September 2019.  
70.	It is relevant to note too that the appellant’s treating neurosurgeon Dr Pitham considered that the appellant’s pain in her lumbar spine was a consequence of the disc disease at L5/S1, which he said was just a normal part of getting older.
71.	As noted above the Medical Assessor assessed the degree of the appellant’s impairment relating to her lumbar spine from the injury by reference to the muscle spasm and lack of movement she had in her lumbar spine.  The muscle spasm would be the cause of the appellant’s pain in her lumbar spine.  Her muscle spasm and lack of movement is a consequence of having a damaged disc at L5/S1, which is due to both a constitutional factor (age) and the discectomy she had on 9 September 2021.  The degenerative changes in her disc of course were rendered symptomatic by her injury on 27 February 2020.  However, had she not had a pre-existing damaged L5/S1 disc her impairment of her lumbar spine would not be nearly as great, because she would not have muscle spasm or lack of movement at L5/S1 without this damaged disc.  In the Appeal Panel’s view, it is therefore at odds with the evidence (being the evidence from which it can be concluded that she had degeneration in her disc at the time of injury) to assume that the proportion of her permanent impairment that is due to her pre-existing damaged disc is 10%.
72.	Consequently, although the Medical Assessor did not provide a sufficient explanation for not engaging s 323(2) of the 1998 Act, he was not wrong not to engage it.
73.	Further, in the Appeal Panel’s view, given the extent of the degeneration in the appellant’s lumbar spine and noting that her impairment is assessed by reference to muscle spasm and loss of movement of her lumbar spine, the Appeal Panel considers that a deduction of 50% (1/2) is an appropriate deduction.
74.	For these reasons, the Appeal Panel has determined that the MAC issued on 
3 September 2024 should be confirmed.