The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

An Appeal Panel hearing was held on March 16, 1999, at the request of a worker advisor, acting on behalf of the claimant. The Panel discussed this appeal on March 16, 1999.

Issue

Whether the claimant's right knee problems commencing in May 1998, and surgery performed in July 1998, are related to the compensable injury of October 16, 1997.

Decision

That the claimant's right knee problems commencing in May 1998, and surgery performed in July 1998, are related to the compensable injury of October 16, 1997.

Background

While employed as a mechanic/truck driver on October 7, 1997, the claimant stepped down from his trailer and twisted his right knee. As a result of the injury, the claimant underwent a right knee arthroscopic medial meniscectomy the day after the accident. The claim was accepted by the Workers Compensation Board (WCB) and wage loss benefits were paid to November 15, 1997, when the claimant returned to work.

File documentation showed that on May 13, 1998, the claimant was referred to an orthopaedic surgeon by his family physician because of continued right knee problems. On June 10, 1998, the orthopaedic surgeon commented that the arthroscopic evaluation of October 16, 1997, demonstrated right knee medial femoral condyle articular surface damage. The claimant had a large degenerative medial meniscal tear as well as fibrillation and partial tears of the inner third of the lateral meniscus. The surgeon remarked that this could have been aggravated by an injury but had the appearance of a long-standing condition.

The orthopaedic surgeon's examination revealed pain localized to the medial aspect of the joint. The surgeon stated that long leg films were repeated and they demonstrated a neutral alignment. Treatment options were discussed. It was suggested that repeat arthroscopic debridement be carried out at which stage an osteochondral mosaic bone graft would be done during the same procedure if indicated. The procedure, according to the specialist, was to restore the normal articular surface of the claimant's medial femoral condyle.

On July 9, 1998, a WCB medical advisor reviewed the file including the June 10, 1998, orthopaedic report. The medical advisor was of the opinion that the pathology was primarily degenerative. The meniscal tear may have represented an enhancement of a previously degenerative meniscus. The medical advisor concluded that the mechanism of injury which occurred in October 1997, was not responsible for the pathology in the knee or for the proposed surgery. Based on the medical advisor's comments, the claimant and orthopaedic specialist were notified that financial responsibility for surgery would not be covered by the WCB and that the claimant was not entitled to further wage loss benefits.

On July 10, 1998, the claimant underwent a right knee arthroscopic debridement, partial lateral meniscectomy and osteochondral mosaic bone graft.

An appeal submission was received from a worker advisor, dated August 28, 1998. The worker advisor made reference to the operative report of October 8, 1997, and to the post-operative diagnosis. The worker advisor stated that a domino effect had taken place whereby the twisting fall caused the enhancement of the tear, which in turn caused the locking of the knee, which caused the damage to the femoral condyle surface. The worker advisor noted that the purpose of the second surgery was to restore a normal articular surface to the claimant's medial femoral condyle. In the opinion of the worker advisor, the October 7, 1997, mechanism of injury was responsible for the pathology/performed surgery.

On October 2, 1998, the Review Office agreed with primary adjudication's earlier decision that the claimant was not entitled to benefits for his right knee problems experienced in 1998. The Review Office based its decision on the following evidence:

• the claimant had significant pre-existing changes in his right knee at the time of his work related accident in October 1997.
• the pre-existing conditions were not the consequence of the work related accident and were considered "high risk" to cause discomfort and right knee dysfunction in the future.
• the work related accident aggravated the pre-existing conditions which led to surgical repair of the torn meniscus.
• degenerative changes noted in the right lateral meniscus and medial femoral condyle caused further right knee symptoms which led to the July 1998 surgery. There were no problems other than findings of the previous repair, with the medial meniscus which contributed significantly to the claimant's right knee problems in 1998.

Subsequently, the worker advisor appealed the Review Office's decision and an oral hearing was arranged.

Reasons

We find that the claimant's right knee problems commencing in May 1998 and subsequent surgery performed in July 1998, were, on a balance of probabilities, related to his compensable injury of October 7th, 1997. In coming to this conclusion, we attached considerable weight to both the October 1997 and the July 1998 operative reports prepared by the treating orthopaedic surgeon.

• October 8th, 1997, Operation: Right Knee Arthroscopic Medial Meniscectomy - "The lateral joint compartment demonstrated and intact articular surfaces to mid as well as posterior third inner aspect of the lateral meniscus demonstrated some fraying which was debrided with a duck bill punch to a smooth surface. The intercondylar notch demonstrated a displaced large, bucket-handle medial meniscus tear. This had the appearance of a longstanding tear with a well rounded parrot-beak tear with obvious signs of a recent deeper bucket-handle tear, most likely caused when the femoral condyle caught the nodular parrot-beak tear and displaced the meniscus. The meniscus was reduced. The limbs of the bucket-handle tear were transected with an arthroscopic scissor. The meniscal fragment was removed in one large piece. The remaining meniscus ends were debrided to a smooth surface with an arthroscopic duck bill punch. The fragments were removed with a debrider. The medial femoral condyle demonstrated a localized area of 1 x 1 cm articular surface damage with loose flaps, detached by the displaced meniscus. This was debrided to a smooth surface."
• July 10th, 1998, Operation: Right Knee Arthroscopic Debridement, Partial Lateral Meniscectomy & Osteochondral Mosaic Bone Graft - "The lateral meniscus inner third posterior portion was degenerated with a prominent tear that was excised conservatively to a smooth surface. The medial compartment demonstrated signs of a previous medial meniscectomy that was done. The localized area of medial femoral condyle articular surface defect bordering the intercondylar notch was evaluated. It was decided to do an osteochondral bone graft transfer. A 10 mm bone graft was then harvested from the lateral portion of the intercondylar notch and transferred to the medial bone, where it was impacted to a smooth surface. The knee was flexed and extended ensuring no impingement." (Emphasis ours)

During the interval between the two surgeries, the claimant was treated conservatively, and yet he continued to experience some discomfort. At the time of the second surgery, the arthroscopic findings demonstrated damage to the claimant's medial femoral condyle, which in the opinion of the orthopaedic surgeon had the appearance of relatively recent onset. The surgeon thought that this discomfort was being caused by the medial femoral condyle articular surface damage. Accordingly, he proceeded with an osteochondral bone graft on July 10th, 1998.

The claimant's appeal is hereby accepted. As an aside, we would like to point out the fact that the employer appeared at the hearing and totally supported the worker in his claim.

Panel Members

R. W. MacNeil, Presiding Officer
A. Finkel, Commissioner
R. Frisken, Commissioner

Recording Secretary, B. Miller

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

Signed at Winnipeg this 5th day of May, 1999