Decision #72/11 - Type: Workers Compensation

Preamble

The worker is appealing a decision made by Review Office of the Workers Compensation Board ("WCB") which determined that his ongoing back complaints were unrelated to his compensable injury of April 21, 2008. The worker disagreed with the decision and an appeal was filed with the Appeal Commission through the Worker Advisor Office. A hearing was held on April 12, 2011 to consider the matter.

Issue

Whether or not responsibility should be accepted for the worker's ongoing back complaints in relation to the April 21, 2008 compensable injury.

Decision

That responsibility should not be accepted for the worker's ongoing back complaints in relation to the April 21, 2008 compensable injury.

Decision: Unanimous

Background

On April 21, 2008, the worker injured his low back region when he slipped while jumping down from a fence at work. The claim for compensation was accepted based on the diagnosis of a low back strain and benefits were paid to the worker to June 2008.

The next contact with the worker was on March 13, 2009 when he advised the WCB that his back difficulties had been ongoing since April but it did not prevent him from continuing to work. Around September/October 2008 his back symptoms increased. On January 12, 2009, his back really started to bother him after cleaning up a water leak.

Subsequent file records showed that primary adjudication contacted the worker, the employer and several co-workers to obtain additional information related to the worker's back complaints and the incident of January 12, 2009.

On June 12, 2009, the worker's file was referred to a WCB medical advisor by primary adjudication. The WCB case manager noted that the worker had been having ongoing problems throughout his employment. The employer and the employees noted that the worker had ongoing neck complaints for which he had a prior surgery and a non-compensable neck fusion. The worker stated that the only thing he did on January 12, 2009 was basically mop a wet floor.

In response to questions posed by the case manager, the WCB medical advisor stated on July 15, 2009:

  1. The current diagnosis appeared to be non-radicular low back pain. An MRI demonstrated annular tears at L4-L5 and L5-S1 levels. The significance of the tears with respect to the low back pain was unknown at this time based on the available medical evidence.
  2. The worker's current problems did not appear to be related to the April 21, 2008 compensable injury. Progress reports from June 6, 2008 and June 11, 2008 indicate good progress and a return to work. The reports indicate a normal range of motion and negative neurological findings. The gradual improvement, the objective examination findings and the successful return to work, were all consistent with a low back strain which resolved within the time frame normally expected. The next report dated February 6, 2009 indicated neck and back pain. Reports after February 6, 2009 indicate increased pain, more diffusely in the cervical, thoracic and lumbosacral areas. With temporal relationship of symptoms and the objective findings reported, the medical advisor indicated he was unable to establish a relationship between the worker's current difficulties and the April 21, 2008 compensable injury.
  3. A recent MRI identified pre-existing annular tears at L4-L5 and L5-S1 but their significance as pain generators and/or contribution to the worker's current disability was unknown at this time.

On July 27, 2009, the WCB case manager advised the worker that he agreed with the opinion expressed by the WCB medical advisor and decided that the worker's claim for a recurrence of his low back strain injury of April 21, 2008 would not be accepted as a WCB responsibility.

On September 28, 2009, a worker advisor asked the WCB case manager to reconsider the decision he made on July 27, 2009 based on a September 15, 2009 report from an orthopaedic surgeon which stated:

"The diagnosis that [the worker] has at the moment certainly correlates to his description of his injury to me.

Secondly, the fact that he had an interim period of good response is not surprising. An annulus rupture is associated with an acute ligamentous injury, acute inflammatory process which then subsides and can improve. However, due to the mechanical dysfunction of the back, the pain will then become more mechanical in nature as [the worker] has developed. There is therefore no reason not to suspect that his present complaint is a direct result of the injury that he sustained last year. The injury to the annulus can be likened to an ankle ligament injury where there is initial response to treatment but chronic instability which develops later. This is exactly the same for the annulus."

On October 26, 2009, the WCB medical advisor indicated that the new information from the orthopaedic surgeon did not alter his previous decision of July 15, 2009. On November 13, 2009, the worker was informed that no change would be made to the decision of July 27, 2009.

In a submission to Review Office dated November 24, 2009, the worker advisor contended that the orthopaedic surgeon's September 15, 2009 report provided medical evidence to support that there was a causal relationship between the worker's increased low back symptoms beginning September/October 2008 and the April 21, 2008 compensable injury.

On March 2, 2010, an external radiologist reviewed x-ray films of the worker's lumbar spine taken September 15, 2009, May 20, 2009 and May 27, 2009. He concluded that there had been no definite internal change between the plain x-rays from May 2009 and September 2009. The MRI scan demonstrated degenerative desiccation of the L4-5 and L5-S1 intervertebral discs without any significant loss of disc space height with associated central disc bulge versus small central disc herniations and associated annular tears at the L4-5 and L5-S1 level.

On March 10, 2010, a WCB orthopaedic consultant was asked to review the file and to answer specific questions posed by Review Office. The consultant responded that the worker's current symptoms were related to degenerative lumbar disc disease, probably at L4-5 and L5-S1 levels. The worker's current symptoms were not related to the low back strain that occurred at work on April 21, 2008. The MRI imaging findings probably represented pre-existing degenerative lumbar disc disease based on the radiologist's opinion dated March 2, 2010.

On April 7, 2010, Review Office asked the WCB orthopaedic consultant to provide a medical opinion as to whether the January 2009 water leak incident aggravated or enhanced the worker's pre-existing lumbar degenerative disc. The consultant responded that the reported mechanism of injury related to the incident in January 2009 would be expected to cause temporary strain or sprain of the back. There was no objective evidence of aggravation of the lumbar disc disease. On a balance of probabilities, the incident did not cause aggravation or enhance the pre-existing lumbar disc disease.

In a decision dated April 8, 2010, Review Office determined that no responsibility should be accepted for the worker's ongoing back complaints. Review Office was of the opinion that the worker had recovered from his April 21, 2008 low back strain injury prior to the cleaning of the leaking tank on January 12, 2009.

Review Office felt that the worker sustained a new accident on January 12, 2009 which resulted in a temporary low back strain/sprain injury. Review Office placed weight on the WCB orthopaedic consultant's opinion outlined on March 10, 2010 and April 7, 2010. It determined that the medical evidence did not support that the worker's ongoing back complaints were related to the April 21, 2008 workplace accident or to cleaning the leaking tank on January 12, 2009. On June 9, 2010, the worker advisor appealed Review Office's decision to the Appeal Commission and a hearing was held.

Reasons

Applicable Legislation

The Appeal Commission and its panels are bound by The Workers Compensation Act (the “Act”), regulations and policies of the Board of Directors. Under subsection 4(1) of the Act, where a worker suffers personal injury by accident arising out of and in the course of employment, compensation shall be paid to the worker by the WCB. Subsection 39(2) of the Act provides that the WCB will pay wage loss benefits until such a time as the worker’s loss of earning capacity resulting from the accident ends.

The Worker’s Position

The worker was assisted by a worker advisor at the hearing. The position advanced on behalf of the worker was that the evidence supported a relationship between the worker's ongoing low back difficulties and the April 21, 2008 compensable injury. It was noted that the worker did not have any low back difficulties prior to the workplace accident. Medical information, beginning with the physiotherapist's May 21, 2008 report supported consistency in reported difficulties at L5-S1. The L5-S1 annulus tear was identified as the pain generator and the opinion from the treating orthopaedic surgeon provided an explanation as to why the worker would have experienced improvement with treatment, then again become symptomatic. Following surgery, the worker's low back issues resolved. It was therefore submitted that the WCB should accept ongoing responsibility.

The Employer’s Position

The employer did not participate in the hearing.

Analysis

The issue before the panel is whether or not responsibility should be accepted for the worker’s ongoing back complaints in relation to the April 21, 2008 compensable injury. In order for the appeal to be successful, the panel must find that the worker has continued to suffer from the effects of the injuries he sustained in the April 21, 2008 workplace accident. We are not able to make that finding.

At the hearing, the worker's evidence was that since undergoing L5-S1 discectomy and pro-disc replacement in April 2010, he has achieved a good recovery and has returned to his full regular duties. It would appear, then, that the L5-S1 disc annular tear noted in the May 27, 2009 MRI was the source of his pain and disability. The question then becomes whether this tear occurred when the worker jumped off the fence at work in April 2008.

Normally, when an individual suffers an injury, one would expect the pain to commence in the immediate period following the injury and continue until the injury resolves. This pattern is not evident in the present case. Here, the evidence discloses that the worker had significant pain immediately following the accident (rated at 8-9 on a scale of 10), which improved over time and he was able to return to work by May 5, 2008. After a few weeks of modified duties, he was able to resume his full regular duties. He had no troubles over the summer, but started to experience discomfort in the area (3 out of 10) in approximately September 2008. This continued to bother him, and in January 2009, when he was performing mopping duties involving side to side movement at the hips, the worker's pain became much worse (7 out of 10). By February 2009, the pain became disabling and he was unable to resume work until after the surgical repair of the L5-S1 annular tear in 2010.

The lack in continuity of the worker's symptoms is troubling. The treating surgeon in his report of September 15, 2009 provides a possible explanation for the interim period of good response. It is important to note, however, that the explanation merely makes the causal relationship between the compensable injury and the annular tear possible, but does not create a probability. The explanation opens the door to a possible relationship but in and of itself does not determine the issue. The surgeon's opinion is: "There is therefore no reason not to suspect that his present complaint is a direct result of the injury that he sustained last year."

When looking at the other available evidence, it seems more likely that the compensable injury was limited to a back strain injury from which the worker recovered and that the annular tear was a subsequent condition attributable to degenerative disc disease. The panel notes that the worker achieved a fairly speedy recovery from the initial accident and his symptoms resolved without the need for much in the way of medical care. He then enjoyed a period of three months with no problems, all while performing regular duties which involved lifting and maneuvering in awkward spaces. This set of facts is consistent with recovery from a back strain injury.

The panel also places significant weight on the description of the L5-S1disc condition by two separate radiologists. The external radiologist retained by the WCB states in his memorandum of March 2, 2010: "There is degenerative dessication of the L4-5 and L5-S1 intervertebral discs without any significant disc space narrowing … At the L5-S1 level, there is central disc bulging versus a small shallow central disc herniation. There is an associated high signal intensity annular tear at the site of the disc bulge…."

Similarly, a second radiologist consulted by the treating surgeon states in his letter of July 27, 2010: "On the May 2009 MRI there is degenerative disc pathology at L4-5 and L5-S1 … At the L5-S1 disc there is a high signal annular tear, which is more extensive measuring approximately 13 mm across x 3 mm in depth. The annular tear is located in the central and right paracentral regions of the disc, and is associated with what I would consider to be a small broad based disc protrusion …."

Both radiologists describe the condition to be degenerative in nature.

On March 10, 2010, the WCB orthopaedic consultant expressed the opinion that the imaging findings on MRI (which would include the L5-S1 annular tear) probably represent pre-existing degenerative lumbar disc disease. The panel accepts this opinion and we therefore conclude that the worker's ongoing back complaints are not related to the April 21, 2008 compensable injury. It follows that responsibility should not be accepted by the WCB.

The worker's appeal is dismissed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
C. Anderson, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 9th day of June, 2011

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