The Appeal CommissionThe Workers Compensation Act of Manitoba

As stated in the preamble, the crux of this appeal deals with whether the worker’s injury on January 27, 2003 is the cause of her ongoing complaints.

Background

Prior Medical History

The worker suffered several other accidents before the January 27, 2003 accident. Although those prior accidents are not relevant to this appeal, a CT scan taken after one of those accidents is. On May 15, 1998 CT scan was taken of the worker’s lumbosacral spine. This CT scan noted three levels of disc protrusion (L3-4, L4-5 and L5-S1), congenital spinal stenosis with potential compromise of the nerve roots and degenerative changes at the L5-S1:

“There is a central disc protrusion which approaches the thecal sac and both L5 nerve roots.

At L4-5, there is a similar central disc protrusion which approaches the thecal sac and both L5 nerve roots.

At the lumbosacral level, the disc is degenerative. There is a central and right lateral disc protrusion compressing the right S1 nerve root posteriorly. The disc is narrowed and end plates sclerotic with associated lateral and anterior osteophyte formation noted.

The patient has a congenitally narrow AP spinal canal diameter which is further compromised by the central disc protrusion at L3-4 and the central disc protrusion at L4-5.”

The January 27, 2003 Accident

On January 27, 2003, the worker hurt her back at work. Her accident report indicates that her “back collapsed” while she was carrying between 5 to 10 lbs of leather and she fell to the floor.

At the hearing, the worker, through her interpreter, denied this mechanism of injury. She testified that she had slipped and fallen on her back. The employer challenged this testimony, pointing to consistent reporting to the contrary at the time of the accident.

After her accident, the worker saw her family physician, who diagnosed a lumbar strain and prescribed physiotherapy. A February 21, 2003 report from the family physician noted that the worker was getting better slowly but that she had only improved by about 30% and still had muscle spasms on the right side.

X-rays were taken on March 3, 2003 which revealed degenerative spurring in the lower dorsal spine and all lumbar disc levels. The L5-S1 disc was narrowed and there was slight narrowing of the discs at T2-3 and L3-4.

These x-rays were reviewed by a WCB medical advisor. It was his opinion that the worker likely suffered a back strain as a result of her accident that had resolved; the residual symptoms were related to her pre-existing degenerative disc disease. A second WCB medical advisor agreed. He thought that the worker should have recovered from her back strain within 2 to 4 weeks.

The worker continued with pain complaints and her physician referred her for a CT scan which was done on July 16, 2003. The results were as follows:

“At the L3-4 level there is mild central prominence of the disc. This contacts the thecal sac, but does not appear to affect the existing nerve roots. There is no evidence for central canal stenosis. There is mild facet overgrowth.

At L4-5, there is diffuse annular prominence. There is moderate facet overgrowth. The central canal is maintained.

At the L5-S1 level, there is degenerative narrowing and desiccation. There is a small focal disc protrusion which contacts the thecal sac, but does not appear to affect the exiting S1 roots. There is no evidence for central canal, or lateral foraminal stenosis.”

The family physician also referred the worker to a physical medicine and rehabilitation specialist (“physiatrist”) who saw the worker on August 11, 2003. It was his opinion that the worker’s examination was normal and that her pain complaints were due to non-anatomic, non-organic factors.

The family physician did not agree. In October 2004, she wrote a report indicating that she thought that the worker’s complaints were due to the disc prolapse at 3 levels. It was her opinion at the time that the worker’s back condition was caused by the prior injury in 1998 and that the January 27, 2003 accident severely aggravated that condition.

A senior WCB medical advisor was not persuaded by this opinion. He reviewed the file on February 21, 2005 and thought that based on the mechanism of injury, the favourable natural history of a strain and the August 11, 2003 physiatry assessment, the worker had materially recovered from the work induced strain by August 11, 2003 and that subsequent pain/dysfunction was related to the natural history of the worker’s pre-existing condition rather than an aggravation of that pre-existing condition or a combined effect. He further stated that the interpretation of the July 16, 2003 lumbosacral CT scan appeared to indicate an overall improvement from the 1998 CT scan.

This opinion was reinforced, to the senior WCB medical advisor’s mind, when he reviewed a March 2, 2005 CT scan and compared it with the 1998 and 2003 CT scans.

The March 2, 2005 CT scan revealed the following:

“At L2-3, a bulging annulus is noted but no focal disc protrusion, spinal stenosis or nerve root compression is identified.

At L3-4, a bulging annulus is noted and there is slight central disc prominence. The exit foramina appear well maintained.

At L4-5, a moderate bulging annulus is demonstrated but no focal disc protrusion is seen. The exit foramina appear well maintained.

At L5-S1, a vacuum phenomenon is noted. There is a relatively large central disc herniation causing an indentation of the adjacent dural sac. Also demonstrated are moderate degenerative changes involving the facet joints bilaterally and there is narrowing of the exit foramina.”

A WCB orthopaedic consultant agreed with the senior WCB medical advisor. After his review of the file he was of the opinion that the March 2, 2005 CT scan findings were indicative of the natural progression of the worker’s pre-existing condition and not the compensable injury.

The worker’s family physician disagreed. She maintained that the worker’s symptoms were related to her compensable injury. In a July 17, 2006 report, she even suggested that the compensable injury ‘induced’ the process of degenerative changes to the worker’s back and was responsible for the worker’s back pain.

Worker’s position:

The worker concedes that she has had prior injuries to her back. She says however that she recovered after each one of those accidents. This was not the case with the January 27, 2003 accident. She continues to be symptomatic as a result of this accident and therefore should receive wage loss benefits. She relies on her family physician’s report in support of her position.

Employer’s Position:

The employer says that the worker’s ongoing complaints are not related to her compensable accident. It relies on the reports of the physiatrist as well as the WCB senior medical advisor and orthopaedic consultant.

Analysis

As stated previously, the issue before the panel is whether the worker is entitled to wage loss benefits after August 11, 2003. To make that determination, we must find on a balance of probabilities that the worker’s back complaints after that date are causally related to her January 27, 2003 accident. We are unable to make that finding.