The Appeal CommissionThe Workers Compensation Act of Manitoba

This appeal deals with the relationship between the worker’s February 6, 2003 compensable injury and his ongoing symptomotology. This relationship dictates the outcome of the worker’s appeal.

Background

On February 6, 2003, the worker injured his lower back when he bent forward, lifted a box of envelopes weighing approximately 45 pounds, and turned to the right to set it down.

The worker saw his family physician with complaints of central low back pain radiating to his right mid-buttocks. On examination he had a 50% decrease in range of motion and loss of lumbar lordosis. There was also tenderness and swelling at the L5 level centrally. He was diagnosed with acute mechanical low back strain and referred for physiotherapy treatment.

The physiotherapist saw the worker a week later. By this time the worker’s symptoms had increased. He was now complaining of pain radiating down the back of his legs to his knees with right groin pain and bilateral testicular numbness. A CT scan was ordered and performed on March 21, 2003. It revealed a central disc protrusion at L4-5 with mild compression of the thecal sac and L5 roots above the lateral recesses as well as mild annular disc prominence at the L3-4. It was otherwise unremarkable.

An orthopaedic surgeon examined the worker on May 21, 2003. He did not find any convincing clinical evidence of significant nerve root compression. He ordered a bone scan to further investigate the cause of the worker’s symptoms. The bone scan was unremarkable with respect to the worker’s lumbar spine.

By the beginning of July 2003, the worker’s physiotherapist thought that the worker could attempt a graduated return to work. The worker was not successful in returning to his full-time regular duties. He only managed to get up to 6 hours per day with increasing symptoms and by July 17, 2003 he went off work and has not returned due to his physical restrictions.

The cause of the worker’s ongoing symptomotology was investigated and commented on by several medical practitioners.

A WCB medical advisor who examined the worker on October 1, 2003 thought that the worker suffered from discogenic back pain which was causing him lumbar spinal dysfunction in terms of range of motion. Importantly he did not find any evidence of pain behaviour or of an abnormal presentation. The WCB medical advisor prescribed several restrictions including no prolonged sitting, standing or walking, limited bending, stooping and crouching, and no weights greater than 5 pounds. He also ordered an MRI and referred the worker to a pain clinic for their opinion. The MRI revealed degenerative changes in the L3-4, L4-5 and L5-S1 levels, which the WCB medical advisor thought would confirm the worker’s discogenic pain findings on examination. This was also the opinion of the pain clinic specialist. A trial of facet joint blocks targeting the L4-5 and L5-S1 levels bilaterally was carried out and accepted by the WCB. As the worker experienced a 50% improvement in his level of pain after the facet joint blocks, the pain clinic specialist recommended a rhizotomy. This procedure was never done as the WCB denied responsibility for it.

A WCB orthopaedic consultant who reviewed the worker’s file on June 25, 2004 and examined him on September 2, 2004 thought that the worker likely only suffered an aggravation of a pre-existing degenerative back condition. Though he pondered why the radiological testing failed to reveal any facet joint arthropathy, he nonetheless suspected this condition given the worker’s favourable response to the facet joint blocks. His opinion was shared by a second WCB medical advisor who put his comments in writing on October 19, 2004. This medical advisor also commented that the worker did not require further treatment but most likely would require preventive restrictions given that he had a “back at risk”.

A senior WCB medical advisor reviewed the file on November 9, 2004 and disagreed with the diagnosis of the worker’s compensable injury. Based on the worker’s symptoms and mechanism of injury he thought that the worker suffered an acute facet joint sprain. He also thought that the worker continued to suffer from the combined effect of the facet joint sprain and pre-existing degenerative process involving the lower lumbar spine. That said, he did not see any evidence of an enhancement of the underlying degenerative process and thought that the worker’s condition would improve with a short course of spinal manipulation combined with a spinal stabilization program. He concurred however with the other two WCB medical advisors that the worker had a back at risk caused by his pre-existing degenerative lower lumbar spine and that he should have long-term preventive restrictions.

The worker was referred to a chiropractor for the spinal manipulation and stabilization program and began preventive vocational rehabilitation.

Worker’s Position

The worker says that he has never recovered from his workplace accident. He says that although the spinal manipulation and stabilization program was helpful, it has not completely resolved his symptoms. He says that his current condition was caused by a combination of his pre-existing degenerative disc disease and his workplace accident which falls under WCB Policy 44.10.20.10. In support of his position, he relies on the November 9, 2004 report by the WCB senior medical advisor as well as the subsequent medical reports from his family physician dated July 4, 2005 confirming his ongoing symptoms and their relationship to the workplace accident, as well as the supplemental information requested by the appeal panel.

Information Requested by the Panel after the Hearing

At the hearing, the worker testified that as he continued to be symptomatic, his family physician sent him to an orthopaedic surgeon for investigation. He also continued to see his treating chiropractor. The panel wrote to the orthopaedic surgeon, the treating chiropractor and a rheumatologist to whom the orthopaedic surgeon referred the worker to obtain information about the worker’s condition and treatment.

The medical report from the orthopaedic surgeon to the worker’s family physician is dated November 4, 2005. The orthopaedic surgeon thought that the worker’s degenerative disc disease was mild. He was unable to find a cause for the worker’s ongoing back pain and questioned whether it could be due to an inflammatory process; subsequent testing ruled this out.

The treating chiropractor to whom the worker was referred by the WCB in November 2004, concurred with the WCB senior medical advisor’s diagnosis of an acute facet joint sprain as a result of his workplace injury. He clarified that the acute phase of this injury was resolved but added that the worker continued to be symptomatic as a result of a lumbar facet syndrome, i.e. chronic pain mediated by the zygo-apophyseal joints, and that this syndrome might be a sequela of his initial facet joint sprain. Other factors that were sustaining the lumbar facet syndrome were the worker’s physical and core muscle de-conditioning, fear-avoidance behaviours and reliance on medication for pain relief.

Analysis

To accept the worker’s appeal this panel must find on a balance of probabilities that the worker’s ongoing symptoms are causally related to his February 6, 2003 workplace accident. We are able to make that finding.

WCB Policy 44.10.20.10 provides that where a worker’s loss of earning capacity is caused in part by a compensable accident and in part by a non-compensable pre-existing condition, or the relationship between them, the WCB will accept the responsibility for the full injurious result of the accident. Where however the workplace injury is no longer contributing to a material degree to the worker’s loss of earning capacity and the non-compensable pre-existing condition has not been enhanced by the workplace injury the WCB will not pay further wage loss benefits. This is not the case where the worker’s inability to work is a result of the workplace injury and the evidence suggests, on a balance of probabilities that the accident, in concert with a pre-existing condition is causing the on-going loss of earning capacity.

The medical evidence before this panel is that the worker suffers from a non-compensable pre-existing degenerative disc disease. Despite this pre-existing condition, the worker was able to work at his job without symptoms up to the date of his accident.

The injury suffered by the worker on February 6, 2003 has been diagnosed as a lumbar sprain/strain, discogenic pain, an aggravation of pre-existing degenerative disc disease and a facet joint sprain. In weighing the medical evidence, the panel finds that the worker did suffer a facet joint sprain on February 6, 2003. We make this finding based on the mechanism of injury, the worker’s positive response to the facet joint blocks and the positive response to treatment for this condition as well as the lack of an inflammatory cause for his condition.

Given the worker’s ongoing symptoms and the treating chiropractor’s opinion that the cause for this ongoing pain is a lumbar facet syndrome and no longer the acute facet joint sprain, the issue becomes whether this lumbar facet syndrome is causally related to the workplace accident. As indicated above we find that it is. While the worker does suffer from a pre-existing degenerative disc condition, there has been no diagnostic confirmation of a facet joint arthropathy or other inflammatory disease that could account for the worker’s ongoing symptoms on the sole basis of degeneration or arthropathy. This is consistent with the WCB senior medical advisor’s opinion in November 2004 that the worker’s condition at that time was due to a combination of pre-existing degeneration and his compensable facet joint sprain. Though he thought a course of spinal manipulation and stabilization would resolve the compensable condition leaving only the pre-existing condition, the worker’s and the chiropractor’s evidence is that this has not yet happened. For these reasons, we accept that the worker’s ongoing symptoms are the sequelae of his workplace accident.

Given our finding that the worker’s ongoing symptoms are causally related to his workplace accident and the fact that the worker was never able to return to his regular employment and subsequently required vocational rehabilitation, we also find that the worker’s entitlement to wage loss benefits beyond March 7, 2005 and his vocational rehabilitation are a direct consequence of his February 6, 2003 compensable injury.