Decision #46/05 - Type: Workers Compensation

Preamble

A non-oral file review was held on January 27, 2005, at the request of a worker advisor, acting on the worker's behalf.

Issue

Whether or not the worker has recovered from the physical effects of the June 1991 injury; and

Whether or not the worker's wage loss benefits have been correctly calculated.

Decision

That the worker has recovered from the physical effects of the June 1991 injury; and

That the worker's wage loss benefits have been correctly calculated.

Decision: Unanimous

Background

In June of 1991, the worker experienced a sharp pain in his lower back while shoveling underneath a belt-conveyor. The diagnosis given at that time was a mid back strain and light duties for the worker were suggested. The worker did not lose any time from work as a result of the accident until April 1992. The Workers Compensation Board (WCB) accepted the claim as a recurrence and the worker was paid wage loss benefits beginning April 11, 1992.

On September 30, 1992, the family physician reported that the worker had been seen on April 10, 1992 and complained of pains in his lower back and limped with his left leg. The impression was "chronic back". The physician also commented, "My first treatment of his back problem was on August 28, 1992 and seemed to be a psychosomatic dysuria. He first mentioned the back injury on October 23, 1991 after which he was seen almost monthly."

In a report to the family physician dated January 15, 1992, an orthopaedic surgeon commented that the worker suffered a rotational injury on the left while shoveling last June. He stated that the worker was off for only three weeks and that he was on light duties following his neck injury from a motor vehicle accident the past November. His impression of the worker's medical status was "mechanical backache, likely due to residual effects from last year's strain either to the facet joints or muscles."

X-rays of the lumbar spine were taken in July 1991. There was no alteration in the curvature of the spine and all vertebral bodies and posterior elements were intact.

The worker was treated at the Health Sciences Centre Pain Clinic (the Pain Clinic) on October 26, 1992 and was given bilateral facet blocks at L4-5 and L5-S1. In a follow-up report dated February 5, 1993, the Pain Clinic reported that the worker received no relief from the facet blocks and that epidural cortisone had been injected with some degree of relief. It was suggested that the worker should be seen again by an orthopaedic specialist and that a CT scan may be required.

A CT scan of the lumbar spine was performed on February 11, 1993. It revealed that the worker had a minor bone deformity at L5-S1 thought to represent a healed spondylolysis. The lateral recess at L5-S1 on the left side was encroached upon. The appearance was "somewhat unusual, but could conceivably represent sequestrate disc material."

On July 7, 1993, the treating orthopaedic specialist stated, in part, "…he is on Demerol, perhaps twice a week, takes muscle relaxants and Tylenol Extra Strength, as well as Gravol and other medications. With the marginal CT results, with some evidence of unilateral spondylolisthesis, slight forward slip, some narrowing of L6-S1, and his severe pain reaction, I think continued conservative management is likely the treatment of choice. Ideally cleaning out the disc space area and a solid spinal fusion would be the treatment of choice, but I fear that as in many cases with this gentleman, it probably would not work."

In a memo dated August 4, 1993, a WCB medical advisor commented that the worker's disability was basically an aggravation of a pre-existing disease.

On August 10, 1993, a different family physician diagnosed the worker with L6 spondylolisthesis at the right and narrowed L6-S1 disc spaces. The physician stated that the worker's possible impairment was flexion/rotational movements.

On August 26, 1993, an MRI examination was performed. The MRI consultant believed there was conjoined nerve root of L5 and S1 on the right and that this was a normal anatomic variant. He did not believe there was significant abnormality at other lumbar levels. Other intervertebral foramina were adequate in size and there was no intradural abnormality.

In a report dated November 1, 1993, a neurologist stated, "Although he is complaining of some symptoms and signs that cannot be explained as an organic lesion, I believe that underneath it all he does have a left L5-S1 disc and I believe that it is time that it was removed… Before that however, I think we should follow the suggestion of the MRI consultant and do a CT-myelogram which will absolutely confirm the lesion."

On November 15, 1993, a WCB medical advisor refused to authorize surgery as he felt there was no clear evidence of any pathology. The medical advisor asked to see further tests results.

The post myelogram CT scan of the lumbosacral spine dated November 15, 1993 revealed, "Segmentation anomaly of the S1 vertebra with malformation of the left S1-S2 facet joint as described above. There is no definite evidence of spinal stenosis or nerve root compression. There has been no change since the previous MRI scan."

On November 17, 1993 the worker underwent surgery. The postoperative diagnosis was "Negative exploration for extruded disc. Possible conjoined roots." The "Addendum" read, "Two silver clips were placed at the distal end of the exploration of the nerve roots for postoperative marking."

On December 10, 1993, a WCB medical advisor stated that there had been no abnormality found at surgery and therefore surgery was not related to the compensable injury. He felt that a diagnosis of chronic pain was a distinct possibility and should be considered.

In a March 14, 1994 report, the treating neurosurgeon indicated that the worker claimed he was no better at all since the surgery and that he was still having radiating pain into his leg and numbness of his foot. The surgeon agreed with the WCB that the worker should return for physiotherapy and exercises and that he should return to work as best he can. The surgeon also commented that he did not know exactly what was wrong with the worker but that he could have had a lumbosacral disc which protruded and then subsided and that he should be given the benefit of doubt in that regard.

On January 24, 1996, a WCB senior medical advisor reviewed the file and stated, "C.I. still consists of a back strain. Ongoing symptoms, subsequent surgery and continued disability do not relate to effects of C.I.".

The worker was assessed at the WCB's Pain Management Unit (PMU) in March 1995. On May 9, 1995, the examining medical advisor said that the worker "likely qualifies for a diagnosis of Chronic Pain Syndrome (CPS)…It would seem likely that abnormal illness behavior was pre-existing…". In a further memo dated July 19, 1995, the examining medical advisor stated, "there is no new information re past employment history or illness behavior to clarify adjudication regarding chronic pain syndrome."

On March 21, 1996, a WCB medical advisor stated that the worker's chronic pain syndrome "…is not a sequelae of the C.I. It is clear that he had chronic pain syndrome prior to this C.I. A history of pain needing unusually large amounts of narcotic even though the diagnosis was elusive date (sic) back to 1985. It may also be that personality style issues of a developmental nature exist in this man (based on my clinical impression). These could be confirmed with testing but given that the medical history shows pre-existing abnormal illness behavior I do not believe we need to pursue testing at this time."

The case was considered by Review Office on August 30, 1996. Review Office overturned the decision made by primary adjudication that the worker's chronic pain syndrome was not compensable. Benefits were therefore reinstated.

In January 1999, a deemed post accident earning capacity was established for the worker at $6.00 per hour for a 40 hour week. The worker's disability pension from his employer continued to be taken into account when calculating his wage loss benefits.

On February 6, 2002, a physician from the Pain Clinic reported that the worker was suffering from facet joint arthropathy and that he was provided with an injection into his facet joints. The worker was also being booked for further treatment in May 2002.

In March 2002, a worker advisor, acting on the worker's behalf, appealed several decisions made by the WCB. The worker advisor presented argument that the worker's deemed earning capacity was inappropriate and that medical aid expenses were warranted.

On April 3, 2002, the worker's treating physician outlined his position that the worker was totally unemployable, that he was still suffering from back pain and that he was incapable of doing even light physical work.

The WCB received a letter from the worker dated April 29, 2002. He stated that he was still suffering from back pain and had recently attended the Health Sciences Centre for a cortisone injection to relieve his pain. The worker also expressed concerns with "the deem" and indicated that he was unemployable and should be back on full WCB benefits.

In a report dated July 31, 2002, the treating chiropractor summarized that the worker continued to suffer with mechanical and disco-radicular symptomatology which has persisted since the 1991 accident. The chiropractor stated that he was treating the worker with respect to his chronic residual pain symptoms.

In a memo dated September 23, 2002, a Review Officer asked a WCB orthopaedic consultant to provide an opinion as to the nature of the worker's current back complaints and their relationship to the 1991 injury. The consultant stated, "I do not think we have a musculoligamentous diagnosis that one can equate to the C.I. occurring June 12/91. There have been no substantive musculoskeletal findings over a 10 yr. period that one can attribute to the C.I. He probably has degenerative disc disease at L5-S1 after surgical intervention & degenerative material was removed at that time. However he continued to have 'normal' plain x-rays."

On November 14, 2002, the worker was interviewed at the WCB's PMU. In a subsequent PMU case conference memo dated December 12, 2002, the PMU determined that the worker did not meet the criteria for chronic pain syndrome as his disability was not proportional in all areas of functioning.

On January 16, 2003, the worker advisor wrote to the WCB's Review Office appealing the determination made by the PMU that the worker did not meet the diagnostic criteria for chronic pain syndrome. The worker advisor also contended that the worker's abdominal stress/irritable bowel syndrome was related to the medication that he took as a result of his back injury and that all treatment at the Pain Clinic should be covered by the WCB.

A follow-up report was received from the Pain Clinic dated March 17, 2003 which noted that the worker was treated in May and December 2002.

On December 5, 2003, a Medical Review Panel (MRP) took place and the results were provided to all involved parties.

In a decision dated March 26, 2004, Review Office decided on eight issues. In particular, Review Office determined that the worker had recovered from the physical effects of his June 1991 injury and that the worker's wage loss benefits had been correctly established. Review Office noted that the MRP had described the worker's initial injury as a musculoligamentous strain of the lumbar spine and that he was no longer suffering from this musculoligamentous strain. Based on these findings by the MRP, Review Office determined that on a physical basis there was no relationship between the worker's current back complaints and his 1991 injury.

With respect to the worker's wage loss benefits, Review Office noted that the worker objected to the WCB considering his post injury earnings to include the total of both his company disability pension and his deem. Review Office stated that calculating wage loss benefits in this manner was consistent with WCB practice prior to January 1, 2001. As of that date, Policy 44.80.30.10, Establishing Post Accident Earning Capacity, codified the practice. In December 2004, the worker advisor appealed the foregoing decisions and a non-oral file review was then arranged.

Reasons

With respect to the first issue under appeal, we are in agreement with the determinations arrived at by Review Office. “The MRP indicated that the worker’s initial injury was a ‘Musculoligamentous strain of lumbar spine.’ They also indicated that the worker is no longer suffering from a musculoligamentous strain. It follows that there is no relationship between the worker’s current back complaints and his 1991 injury on a physical basis.”

The MRP identifies absolutely no current physical pathology. In addition, there is nothing in the recent MRI and/or NCS (nerve conduction studies) to suggest pathology, which is in any way causally related to the mechanism of the 1991 injury.

We note that the worker was first diagnosed with myofascial pain some 13 years after the compensable injury and 12 years after he had stopped working. In a letter dated November 30, 2004 to the worker’s worker advisor, the examining physician recorded the following comments:

“Reviewing the mechanics of his initial strain injury shoveling for prolonged periods of time, the initial diagnosis of muscle strain is appropriate. I am impressed with my findings of myofascial trigger point activity in muscles of the low back and hip, i.e., quadratus lumborum and gluteus minimus often strained in actions of forward bending, lifting and twisting such as performed in shoveling. These findings were not specifically mentioned in the orthopaedic examinations in past documents.”

Given the substantial passage of time as well as the extensive medical investigations conducted over this same 13 year period in which the existence of such a condition was never in any way or at any time disclosed, we find the myofascial pain condition is too remote to be causally connected to the compensable injury.

In 1996, Review Office restored compensation benefits to the worker on the basis that he had CPS. The worker advisor acting on behalf of the worker has asserted that CPS is a physical condition. However, we concur with the conclusions reached by Review Office as to whether the worker has CPS and if he does, whether it is causally related to his 1991 injury.

“Review Office weighed the MRP report and that of the PMU [pain management unit] against the criteria used by the WCB to diagnosis (sic) CPS. It is of the opinion that the evidence unequivocally supports the position that the worker has recovered from the psychological effects of his June 1991 injury. He no longer has any form of depression. He does not meet the WCB’s CPS diagnostic criteria that require that his:

‘Pain results in a marked disability that affects proportionally…[his] occupation, social and recreational areas of functioning. Disability affecting solely or disproportionately their occupational area of function only is not an indication of CPS.’

As per the worker advisor and the worker, the worker’s pain renders him unemployable. It is clear that this level of disability does not extend to other areas of the worker’s life. It follows that he does not have CPS in a workers compensation context.”

In addition to the foregoing, we prefer to place more weight on the evidence put forth by the PMU respecting the CPS diagnosis as opposed to certain findings made by the MRP. At the time of its examination, the MRP diagnosed the worker’s condition as CPS and concluded that this condition was causally related to the worker’s June 1991 injury. “There is a temporal and historical relationship of an initial musculoligamentous injury persisting and ultimately leading to the chronic pain syndrome.”

We note that the MRP consisted largely of orthopaedic specialists, whereas the physicians who make up the PMU of the WCB have a generally recognized expertise in the field of pain management and have developed criteria for assessment purposes. It is apparent that the members of the MRP during the course of its examination and formulation of subsequent findings did not apply the specific chronic pain syndrome criteria, which are employed by the WCB when establishing a diagnosis of CPS.

After having considered all of the evidence, we find that the worker has recovered from the physical effects of the June 1991 injury. Accordingly, the appeal of this issue is hereby dismissed.

As to the second issue brought forward on appeal, the weight of evidence confirms that the barriers precluding the worker’s returning to work are not causally related to his compensable injury and therefore the deem is appropriate. In addition, we find that the deduction of the disability pension is in accordance with established WCB policy. We further find that the worker’s wage loss benefits have been correctly calculated. The appeal of this issue is also hereby dismissed.

Panel Members

R. W. MacNeil, Presiding Officer
A. Finkel, Commissioner
M. Day, Commissioner

Recording Secretary, B. Miller

R.W. MacNeil - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 18th day of March, 2005

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