The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

This appeal essentially deals with the issue of whether a workplace injury enhanced the worker's pre-existing degenerative knee condition.

In July, 2004, the worker suffered a compensable meniscal tear to his knee. When an arthroscopy was done, extensive degeneration was found in the knee which required a total knee replacement. The worker says that responsibility should be accepted for the total knee replacement, even if the accident is only partially responsible for his knee condition. He says that prior to the workplace accident he did not have any knee pain. He also says that the workplace injury sped up the pre-existing degenerative process by 5 to 6 years.

The Workers Compensation Board disagreed. This position was upheld by the Review Office in a decision dated December 19, 2005. It is this decision that the worker appealed to the Appeal Commission.

An appeal panel hearing was held on June 6, 2006. The worker appeared and provided evidence. No one appeared on behalf of the accident employer.

Issue

Whether or not responsibility for the total knee replacement surgery should be accepted.

Decision

That responsibility for the total knee replacement surgery should not be accepted.

Decision: Unanimous

Background

Reasons

Background
On July 9, 2004 the worker injured his left knee at work when he twisted it pushing a stalled vehicle.

He saw his doctor on July 12, 2004 who initially diagnosed him with a sprained knee. "Mild osteoarthritis" was listed as a pre-existing condition.

On July 23, 2004, the worker attended a second physician for treatment with complaints of his knee giving way and swelling. The examination revealed effusion and MCL tenderness with clicking. The physician arranged for x-rays to rule out a possible cartilage tear.

An x-ray was taken of the worker's left knee on August 19, 2004. The results were as follows:

"There is minor degenerative spurring at several of the articular margins but the joint space is reasonably well preserved. Several small calcified joint bodies are evident just above the tibial plateau but no joint effusion is seen and no other significant abnormality is recognized."

Then, on September 10, 2004, the worker saw an orthopaedic specialist who thought that the worker might have a medial meniscal tear.

The left knee arthroscopy on December 14, 2004 confirmed this diagnosis. However, it also revealed Type III chondromalacia over the medial facet of the patella, degenerative changes on the femoral trochlea, a large area of Type IV chondromalacia on most of the medial femoral condyle and degenerative changes on the tibial side.

At the hearing, the worker testified that following this surgery, the orthopaedic specialist told him that he would most likely require a knee replacement due to the extensive degeneration.

This advice is confirmed in a follow-up report dated February 10, 2005:

"This gentleman had arthroscopic surgery of his left knee. We found a tear of the medial meniscus. Unfortunately, we also found some Type IV chondromalacia on the patellofemoral joint in the medial femoral compartment. He is doing reasonably well. Mechanical symptoms seem to have improved. There is no effusion. Portals have nicely healed. Range of motion of his knee is full…I think this gentleman should be able to return to work on February 14th. I would suggest to go back to work on light duties and he should remain on light duties for as long as possible."

On April 13, 2005, the orthopaedic specialist indicated that the worker's brace, which was prescribed to him, was working fine for him while he was at work. When he returned home from work, however, he had persistent pain which would frequently wake him up at night. It was the specialist's opinion that a knee replacement would have to be discussed.

On August 12, 2005, the orthopaedic specialist reported that the worker still had knee difficulties and that he was on a waiting list for a left total knee replacement.

The worker's knee was assessed by a WCB orthopaedic consultant on October 6, 2005. It was the consultant's opinion that the worker likely suffered a torn medial meniscus at the time of his work injury and that there was other pre-existing pathology. He felt that a total knee replacement was appropriate treatment for the pre-existing degenerative changes. However, he did not feel that a total knee replacement was causally related to the compensable injury.

After reviewing x-rays of the worker's left knee, the WCB orthopaedic consultant advised the treating orthopaedic specialist on October 20, 2005 that the WCB would not accept financial responsibility for the proposed left total knee replacement:

"We feel the indication for this surgery is the degenerative arthrosis of the left knee. This condition was present prior to [the worker's] work-related injury of July 9, 2004."

Worker's position
The worker concedes that the degeneration in his knee pre-existed the July 9, 2004 workplace accident. He says however that prior to the accident he was asymptomatic. Given his pre-accident presentation, he would not have required a total knee replacement until 5 to 6 years later. He therefore takes the position that the accident sped up the degenerative process.

Analysis
To accept the worker's appeal we must find that the total knee replacement is causally related to his workplace accident. We are unable to make that finding.

The worker's injury was a twisting injury which we find consistent with a meniscal tear. It is not however, on a balance of probabilities, consistent with degeneration.

Degeneration is a natural and progressive process. While it may be enhanced by injury, we do not find that this was the case for the worker's left knee. Indeed, when the arthroscopy was performed 5 to 6 months post accident, Type IV chondromalacia was already found, indicating a well advanced degeneration. The orthopaedic specialist already thought at that time that a total knee replacement would be needed.

We have turned our minds to whether the workplace injury in any way sped up the degenerative process. Once again we are unable to make that finding. The medical reports suggest that the worker's meniscal tear complaints resolved by February, 2005, allowing him to return to work. The remaining symptoms were pain, which in this case is consistent with degeneration. Though the worker may not have experienced this pain prior to his workplace injury, we do not find that this is sufficient evidence to causally link the compensable injury to the degeneration.

In these circumstances we are unable to find, on a balance of probabilities, that responsibility should be accepted for the worker's total knee replacement.

Accordingly the worker's appeal is denied.

Panel Members

L. Martin, Presiding Officer
A. Finkel, Commissioner
L. Butler, Commissioner
Recording Secretary, B. Miller

L. Martin - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 24th day of July, 2006