Adams v Accident Compensation Corporation

IN THE DISTRICT COURT HELD AT DUNEDIN Decision No. 268 /2007 IN THE MATTER of the Injury Prevention, Rehabilitation and Compensation Act 2001 AND IN THE MATTER of an appeal pursuant to Section 149 of the Act BETWEEN SUSAN MARGARET ADAMS (Al 266/06) Appellant AND ACCIDENT COMPENSATION CORPORATION Respondent HEARD at DUNEDIN on 21 November 2007 APPEARANCES Mr P Sara, Counsel for Appellant Mr H Evans, Counsel for Respondent. RESERVED JUDGMENT OF JUDGE M J BEATTIE [1] The issue in this appeal arises from the respondent's decision of 8 November 2005, whereby it suspended entitlements to the appellant in respect of her covered back injury on the grounds that her then current condition was no longer attributable to that personal injury. (2] The background facts relevant to the issue in this appeal may be stated as follows: . In July 2005 the appellant, then aged 59 years, was employed as a dental assistant. 266.06 (pg) 2 On 29 July 2005 the appellant suffered an injury to her lower back as a consequence of a twisting movement that she undertook while using dental equipment for the dentist in the course of her work with him The twisting movement brought about the onset of left-sided pain. . The initial treatment consisted of anti-Inflammatories and physiotherapy, but the low back pain remained and her normal movements were considerably restricted. The appellant had presented to her GP for treatment without any previous history of back problems The appellant's GP, Dr Mcleod, referred her to Mr Patrick Medlicott, Orthopaedic Specialist, for assessment. Mr Medlicott carried out an examination and obtained X-rays. Mr Medlicott's assessment as reported to Dr Mcleod on 15 September 2005, stated as follows: "Clinically she would appear to have an L4/15 disc protrusion or lateral canal stenosis as a result of her postural problems at work and also a probable disc protrusion and/or lateral canal stenosis on the left." An MRI scan was arranged by Mr Medlicott and undertaken on 7 October 2005. Consequent upon that MRI scan Mr Medlicott referred the appellant to Mr Bruce Hodgson, Orthopaedic Surgeon, at Dunedin. The MRI scan had identified that the appellant had significant spinal stenosis at L4/5 with a a combination of problems including degenerative spondylolisthesis causing forward slip of L4 on L5. The report of the MRI scan was also provided to the respondent who determined that the appellant's ongoing problems were associated with the spondylolisthesis at L4/5 and was not associated with any lumbar sprain which was the initial injury On 8 November 2005 the respondent issued its decision suspending entitlements. On 10 November 2005 Mr Hodgson reported to Mr Medlicott that in his opinion there was a need for surgery to decompress the L4/L5 level. On 14 December 2005 Mr Hodgson carried out L4/L5 decompression surgery. . The appellant sought a review of the respondent's decision. A review hearing took place on 9 May 2006 at which Mr Sara introduced two reports from Mr Hodgson. By decision dated 1 June 2006 the Reviewer confirmed the respondent's decision, he finding that the appellant's ongoing problems were associated with her pre-existing degenerative condition which had been rendered symptomatic by the July incident. For the purposes of the appeal to this Court further reports have been submitted by Mr Hodgson on behalf of the appellant and a further report from Mr Medlicott has been introduced by the respondent [3] The two specialists who have prepared medical reports on the appellant's condition are Mr Hodgson and Mr Medlicott. In fact, Mr Hodgson has provided seven reports or letters and Mr Medlicott three. In addition to those medical reports there is the report of the MRI scan of 7 October 2005. [4] The starting point would seem to be Mr Medlicott referring the appellant to Mr Hodgson following the obtaining of the MRI scan, which he did by letter of 21 October 2005. At the same time Mr Medlicott reported to the appellant's GP, Dr Mcleod of Wanaka, and his report gives some detail of Mr Medlicott's interpretation of the MRI scan. In that letter he stated as follows: "I reviewed this lady today with her MRI scan. This shows she has very significant spinal stenosis at L4/L5 with a combination of problems. One is a degenerative spondylolisthesis at L4/L5 causing forward slip of L4 on L5. She also has massive facet joint hypertrophy and ligamentum flavum hypertrophy and severe narrowing of the central canal and moderate narrowing of the lateral canal on both sides affecting both L5 nerve roots. The L5/S1 level is reasonably satisfactory. The L3/L4 level shows some degree of stenosis but nothing compared of the L4/L5. Other levels appear satisfactory. I have referred her to Bruce Hodgson for an opinion and I suspect he will advise she has a decompression and surgical fusion at L4/L5." [5] Mr Hodgson first reported to Mr Medlicott on 10 November 2005 after seeing and examining the appellant. Whilst I set out the salient points of Mr Hodgson's report it must be noted that following the surgery which he carried out in December 2005 Mr Hodgson changed his opinion significantly. After reviewing the MRI scan, Mr Hodgson noted as follows: 'Mrs Adams has significant spinal stenosis on the basis of changes at the L4/5 level which I believe relate to the spondylolisthesis. I have told her today that there is nothing to suggest an acute event on these scans despite her development of the problems following the incident on 29 July 2005. The ACC have written to her this week to indicate that they are not covering her claim and I have told her that I would tend to agree with this decision given my clinical history findings and changes on the x-rays and MRI scan. That said, she does need surgery to decompress the L4/5 level and create a fusion at that level because of the spondylolisthesis. I have discussed this with her today including the outcome, the length of time in hospital, the aftercare and a brief discussion of the complications." [6] Following the surgery which Mr Hodgson carried out on 14 December 2005, he reported to Mr Sara on 15 December 2005 and the salient points of his report are as follows: Her plain x-rays have shown a sacrolisation of the 5" lumbar vertebra on the right hand side. With this we know that there is increased stress placed on the L4/5 level (level above) and in fact she has the hallmarks of this sort of stress over a number of years with the development of degenerative changes present at that level and subsequently the spondylolisthesis. There are degenerative changes throughout jthe rest of her spine and in particular at L3/4 and L2/3. The findings on the plain x-rays were also confirmed on the MRI scan. This showed marked thickening of the facet joints at the back part of the spine as well as the ligamentum flavum hypertrophy (the ligament adjoining the joints). The operative findings confirmed the enlarged facet joints and marked thickening of the ligamentum flavum with the bulge of the L4/5 disc anteriorly. The L4/5 disc did not require a decompression following the removal of the facet joints and thickened ligamentum flavum (laminectomy). All this considered, according to Mrs Adams, she developed the problem in the incident on 29 July 2005. I am mindful that she had indicated to me that prior to her incident she was able to walk up to 5 km per day whereas following the incident she was really unable to walk more than a hundred metres. Taking this into account something has obviously happened at the time of the incident that has precipitated her problem and ! would suspect this has been the bulge of the L4/5 disc. I have not been able to confirm this on either the plain xrays or MRI scanning but I did note the bulge of the L4/5 disc at surgery. This then raises the possibility that something acute has happened to tip the balance. 1 hink this is most likely to be the L4/5 disc bulge. I suspect this may well have occurred at the time of the initial incident. " 7] Mr Sara sought clarification from Mr Hodgson about his comment about something acute happening to "tip the balance". Mr Hodgson replied to that on 9 March 2006 when he stated: "I believe Mrs Adams sustained a tortional injury in some regard which lead to a split in the lining of the disc and subsequent bulge of the disc. This tipped the balance of the L4/5 level and lead to the onset of nerve root compression and irritation." [8] The letters from Mr Hodgson were provided to the respondent who sought comment from its Branch Medical Advisor. He commented as follows: 5 "I would point out that this does not alter the fact that the surgery he undertook was to relieve her symptoms from spondylolisthesis, and specifically he did not operate on the disc bulge which may have been caused on 29 July 2005 because this was not require medically. Had he felt it was appropriate I am sure he would have proceeded to this whilst she was on the table. According to Mr Hodgson she is now doing well medically which suggests that the surgery she had was appropriate for the condition he wished to improve, i.e., her pre-existing spondylolisthesis which did not become symptomatic until after the event on 29 July 2006. The disc bulge at L4/5 is not giving her ongoing symptoms.' [9] In a further letter from Mr Hodgson to Mr Sara of 26 April 2006, he gave a further explanation about the surgery he had performed and his advice was as follows: "Mrs Adams has had a spondylolisthesis at L4/5 with facet joint hypertrophy, thickening of he ligamentum flavum and spinal stenosis. She had also developed a bulge of the L4/5 disc In my letter to you on 9 March 2006 (question 3) / stated I believe that Mrs Adams sustained a torsional injury to her back which has split the lining of the L4/5 disc and lead to the subsequent bulge. I believe this was the incident that tipped the balance and lead to the onset of her pain and clinical symptomatology. The surgery that I carried out on 14 December 2005 was to "decompress" the spinal nerve roots and whatever structures necessary to achieve that goal. I used the word "decompression" in a broad sense. In that this can encompass a number of specific surgical procedure, all carried out via a posterior approach. A laminectomy (removal of the bony lamina). An undercutting facetectomy (thinning of the hypertrophic or enlarged facet joints. MAWN . Removal of the ligamentum flavum Discectomy. Foraminotomy (enlargement of a small nerve root canal where the nerve runs out from the spinal canal and out of the vertebral column into the abdomen and pelvis and finally into the leg) The aim of the surgical procedure is to carry out a decompression of the spinal contents and nerve roots. When there is an anterior displacement of one vertebra on another (spondylolisthesis) Suc Adams' case there is a mechanical instability that has developed (this leading to the anterior displacement) As part of her surgical procedure a posterior decompression was carried out. This invodived the posterior elements (lamina, facet joints, ligamentum flavum) In order to enlarge the spinal canal and free the nerve roots it is not always necessary to carry out a discectomy (anterior to the spinal sac contents) once the posterior structures have been removed and the spinal canal thereby enlarged even though the disc prolapse had caused the initial compression. The disc prolapse (anteriorly) pushes backwards against the dural sac and nerve roots. It jams them against the posterior structures such as the lamina, facet joints and ligamentum flavum. Once the posterior structures have been removed (or enlarged) the dural sac bulges outward and has enough room such that the anteriorly placed disc bulge does not need to be decompressed. It is quite common in my practise to carry out a posterior element decompression in a patient with a relatively small canal who also has had a disc prolapse. This is done by decompressing the spinal canal and removing the posterior elements while not 6 necessarily needing to carry out a discectomy. If the disc is completely ruptured and there is a free fragment in the canal or an extruded fragment from the disc then this will necessitate removal of the disc fragments; however, with Mrs Adams this was not the case and while the L4/5 disc was bulging there was no extruded or sequested (separated) fragments that required removal. Following the laminectomy, undercutting facetectomy and removal of the ligamentum flavum the spinal canal in my opinion was quite adequately decompressed and nothing further was to be gained by carrying out the discectomy other than to render the situation more unstable. A spinal fusion was carried out to stabilise the already unstable situation. In summary my surgery was carried out to decompress the compromised spinal canal that had been rendered such by the torsional injury that occurred to the disc at L4/5 at the time of her injury on 29 July 2005." [10] In a further letter of 8 May 2006 to Mr Sara, Mr Hodgson explained why he had changed his opinion from that initially expressed in his letter of 10 November 2005. Mr Hodgson stated as follows: "I have indeed changed my opinion from the letter / sent to Mr Medlicott. At that stage / did not have the benefit of having operated on this lady. At the time of surgery I noted the bulging disc despite the fact that there were other changes associated with the spondylolisthesis (facet joint hypertrophy and thickened ligamentum flavum). It was the presence of this change that indicated to me that this may well have been the pathology that tipped the balance and led to the onset of the significant pain that Mrs Adams experienced The Branch Medical Officer is quite right to indicate that the changes in the facet joints and ligamentum flavum were undoubtedly there prior to this incident however Mrs Adams had been quite functional and without pain. The disc protrusion tipped the balance despite the radiologic appearances of this prior to surgery (plain xray, MRI scan). It was the findings at surgery which led me to change my opinion. I think it is most important to treat all aspects of a patient's problem, namely their clinical symptoms and signs, plain xray and MRI scannings and indeed their operative findings. In general terms I treat patients and their xrays. Decisions are made based on patient's clinical and surgical findings rather than just on xray or MRI scan findings.' [11] The various correspondence from Mr Hodgson was referred to Mr Medlicott for comment by respondent's counsel and he gave his response in a letter dated 18 December 2006. The relevant passages from his letter are as follows: "My clinical notes document my impressions of this lady and my physical findings and interpretation of imaging reports. The underlying causation of this lady's problem is degenerative spinal stenosis. The disc bulge that Mr Hodgson refers to and the MRI notes and what was found at the decompression surgery (Operation Note) may have rendered symptomatic a very compromised pre existing neural canal. I am sure you realise that temporality is not causality. From the patients point of view an incident that gives rise to symptoms is always felt to be the causal nature and to have caused the pathology. Medically however there is a large amount of pathology 7 that is not symptomatic until some often relatively minor incident renders it symptomatic. note that Mr Hodgson did not remove the disc at the time of surgery but simply did a posterior decompression. This would suggest that it was not the central mild disc protrusion that was the cause of the rendering symptomatic the back problem. This is of course however pure conjecture. I believe what Mr Hodgson has described in his letter of 06.03.06 is classical gradual process degenerative spinal disease rendered symptomatic.' DECISION [12] The respondent's decision which is now the subject of this appeal was made on 8 November 2005 and seems to have been made solely on the basis of an MRI scan carried out on 7 October 2005. The only medical comment which the respondent had was the brief letter which Mr Medlicott sent to the appellant's GP and which was copied to ACC. [13] It was only after the respondent had made its decision to suspend entitlements that Mr Hodgson reported and then subsequently carried out surgery as was foreshadowed in Mr Medlicott's letter. [14] The interpretation made by the respondent of that MRI scan, as it stated in its decision letter was that "any lumbar strain from the initial event of 29 July 2005 will have been spent and the only ongoing cause of incapacity is due to the non-accident related spinal stenosis and spondylolisthesis". [15] I do note that the respondent's view, as expressed in its decision, could not be regarded as unsupported as Mr Hodgson in effect came to a similar view in his report to Mr Medlicott of 10 November 2005. It is to be remembered, however, that this opinion was given before he had carried out the surgery. I consider that the views expressed by Mr Hodgson post-surgery are views which need to be carefully considered. [16] If it is acknowledged that the general state of the appellant's lumbar spine was as interpreted in the MRI scan and that in general her back would have been in a degenerative condition prior to July 2005, it is equally the case that that degenerative condition was causing the appellant no problems either as to range of movement or as a source of pain. The evidence, confirmed by her GP, is that she had never had any back problems prior to this incident and she herself said that she was a fit and active person who was able to go for long walks without any problems. [17] If that is taken as the starting point then it is the case that the incident of 29 July 2005 caused something which changed that benign and asymptomatic state of affairs to a situation of significant pain in her lumbar spine. [18] That pain, I find, had its source in the nerve root compromise at L4/5, the MRI scan shows that it was only at that level that the nerves were compromised even though her degeneration was widespread, and in particular at L2/3, L3/4, and L5/S1. [19] The MRI scan shows that at L4/5 there was a Grade I anterior spondylolisthesis. It was therefore at this level that the degeneration was at its greatest. [20] In his report of 15 December 2005 Mr Hodgson reports on what the MRI scan told him and what his own surgical investigations revealed, and he noted the fact of the degenerative changes throughout her spine and he also noted that the appellant had previously had no problems with her back and he too concluded that something had obviously happened at the time of the incident that precipitated her problem. His assessment was that it was the twisting movement which caused a bulge of the L4/5 disc and he said that it was that disc bulge that tipped the balance. [21] Mr Hodgson amplified on that phrase in his report of 9 March when he said that the disc bulge, sustained by a tortional injury led to the onset of nerve root compression and irritation. It was the nerve root compression that was causing the pain. [22] in his report of 26 April 2006 Mr Hodgson set out in great detail the nature of the surgery he carried out and also the reasons for it. He summarised that surgery by stating that it was carried out to decompress the compromised spinal canal that had been rendered such by the tortional injury that had occurred to the disc at L4/5 at the time of her injury on 29 July 2005. Again, Mr Hodgson is referring to the need to free the nerve roots. [23] Mr Medlicott also alludes to the fact of nerve compromise in his report of 21 October 2005 to Dr Mcleod. He referred to the spondylolisthesis at L4/5 causing a forward slip of L4 onto L5. This indeed is what I find that the evidence establishes occurred in the incident of 29 July 2005. The spondylolisthetic condition of the appellant's spine at L4/5 was such that the twisting injury caused the forward slip which 9 rendered the nerve roots impeded, this set off the pain and this state of affairs continued until Mr Hodgson remedied the matter by way of surgery in December 2005. [24] I am quite satisfied from the evidence that has been presented that the appellant was suffering from nerve root compromise at L4/5 arising from the disc bulge which had been caused in the tortional injury suffered by her and that this injury continued untreated until Mr Hodgson's surgery in December 2005. [25] I find that Mr Hodgson's explanation for his surgery, as contained in his letter of 26 April 2006, clearly identifies that this surgery was necessary not only because of the appellant's general spondylolisthetic condition but also specifically to alleviate the nerve root compromise at L4/5. [26] In those circumstances, I indicate that such surgery ought to have been covered by the respondent as part of its obligations under the cover granted to the appellant and it is certainly the case that at the time the respondent made its decision to suspend entitlements, there was no basis for so doing as the effects of the appellant's personal injury were still very evident and causing her significant problems. [27] In summary, therefore, I find that the respondent's decision cannot be sustained and it is hereby quashed to the effect that the appellant is entitled to have entitlements for her covered injury reinstated and for so long thereafter as the medical evidence determines that she continued to suffer from the effects of the disc bulge at L4/5 which had caused the onset of pain by reason of nerve root compromise. (28] The appellant being successful I allow solicitor's costs of $2,500 together with qualifying disbursements including the cost of any medical reports that may not have hitherto been met by the respondent. DATED this IS' day of December 2008 M J Beattie District Court Judge