Decision #01/00 - Type: Workers Compensation


An Appeal Panel hearing was held on April 20, 1999, at the request of the claimant's union representative.  The union representative was appealing a decision of the Review Office of the Workers Compensation Board (WCB) which determined that the claimant was not entitled to payment of further wage loss benefits beyond March 6, 1998.  The Panel discussed the appeal on several occasions, the last one being November 29, 1999.


Whether or not the worker was entitled to payment of further wage loss benefits beyond March 6, 1998.


That the worker is entitled to payment of further wage loss benefits beyond March 6, 1998.


On September 15, 1997, the claimant was unloading barrels from a truck when he slipped, lost his footing, and twisted/sprained his right knee. The diagnoses reported was an acute traumatic right knee effusion and later, a right knee meniscal tear. The claim was accepted by the WCB and benefits commenced on September 17, 1997.

On November 14, 1997, an orthopaedic specialist reported that the claimant had ongoing anterior and medial pain that was associated with locking episodes. According to the specialist, x-rays showed significant degenerative changes, mediolateral and patellofemoral. The specialist was of the opinion that the claimant had an ACL deficient knee, which was likely, chronic. "He likely has an acute meniscal tear or a degenerative chondral flap on the medial side." An arthroscope was suggested.

In a letter to the orthopaedic specialist dated December 5, 1997, a WCB medical advisor authorized the proposed right knee surgery. The medical advisor stated that the "total extent of board responsibility in this case will be dependent in the long term on your operative findings as it would appear that there is associated pre-existing pathology within this knee joint such as the ACL deficiency and probable chondromalacia neither of which can be attributed to the effects of the compensable injury per se."

On January 12, 1998, the claimant underwent a right knee scope and debridement. The post-operative diagnosis was right knee osteoarthritis.

Following consultation with a WCB medical advisor on February 16, 1998, the claimant was advised by Claims Services that any time loss occurring beyond February 23, 1998, six weeks from the date of surgery, was a result of his pre-existing condition.

Claims Services further stated that the claimant likely aggravated his pre-existing osteoarthritis as a result of his work duties. The weight of evidence including the history of injury, the diagnosis of injury, expected symptom duration, the current clinical findings and the time that had passed did not support an ongoing cause and effect relationship between the work injury and the claimant's current difficulties. It was concluded that the claimant had essentially recovered from the work injury and that compensation benefits would end on March 6, 1998. This decision was later confirmed by Claims Services in a letter to the claimant dated April 15, 1998.

On September 23, 1998, a union representative, acting on behalf of the claimant, noted that it was Claims Services' opinion that the claimant's pre-existing condition was responsible for his symptoms and ongoing problems in his right knee. The union representative contended, however, that on a balance of probabilities, the claimant's work-related injury and required surgery enhanced the pre-existing condition. The union representative stated, that, "Workers Compensation Board Policy on pre-existing conditions makes the Board fully responsible for the injurious result of an accident if the pre-existing condition has been enhanced as the result of an accident arising out of and in the course of employment." Based on this, the union representative requested that the WCB continue its responsibility in the form of medical services and wage loss benefits.

Prior to considering the appeal, Review Office sought a medical opinion from a WCB orthopaedic consultant on October 6, 1998. In response to questions posed by Review Office, the consultant stated the following:

  • the most likely diagnosis resulting from the accident was "post traumatic synovitis due to aggravation of extensive pre-existing osteoarthritis of the Rt knee."
  • given the surgical findings, the accident aggravated the underlying condition. Enhancement had not been proven.
  • when asked whether the accident led to surgery on the underlying condition, the consultant stated, "The knee remained symptomatic post CI and they were looking for a torn meniscus as a result of CI. None was found; only the extensive pre-existing O/A".

On October 9, 1998, Review Office determined that the worker was not entitled to payment of further wage loss benefits beyond March 6, 1998. Review Office noted that the union representative quoted the definition of enhancement found in the policy. Review Office stated that this definition could not be taken in a global fashion to mean that all workers who undergo surgery have necessarily permanently enhanced the pre-existing conditions by reason of their accidents. The treating orthopaedic consultant suspected a torn meniscus and for this reason he performed the arthroscopy. The arthroscopy however did not substantiate this diagnosis, as there were no torn menisci detected. "The entire pathology found during the arthroscopy would have pre-existed the accident by a substantial period of time despite the worker's claim that he never had any prior knee trouble before this accident." Review Office also made reference to WCB policy on pre-existing conditions, namely

It was Review Office's opinion that the claimant had recovered from the effects of the accident and the surgical procedure by March 6, 1998. It was felt that any conditions beyond this time were more probably the result of the pre-existing condition and not the accident or the aggravation sustained in the accident. The worker was therefore not entitled to benefits beyond March 6, 1998. It was the opinion of Review Office that enhancement of the pre-existing condition by reason of this accident had not been proven.

On February 16, 1999, the union representative appealed Review Office's decision and requested an oral hearing. The union representative contended that the claimant suffered from an enhancement of his pre-existing condition and provided a January 7, 1999, report from the treating physician in support of his position. On April 20, 1999, an oral hearing was convened.

Following the hearing and discussion of the case, the Appeal Panel requested and received reports from the treating orthopaedic specialist dated May 25, 1999, and from the attending physician dated June 14, 1999. These were then forwarded to the interested parties for comment.

On July 20, 1999, the Appeal Panel met again to discuss the case and decided to arrange for the claimant to be examined by an orthopaedic consultant. This examination later took place on September 23, 1999. In brief, the independent orthopaedic consultant stated that the claimant suffered from right knee arthrosis and ACL deficiency to the right knee. On a balance of probabilities, the claimant probably did not sustain an ACL injury to his knee at the time of this accident although it cannot be totally excluded. The independent orthopaedic consultant indicated that the claimant suffered from osteoarthritis of his right knee and that the work place injury enhanced the osteoarthritic knee from the point of view that it had not settled and he was still quite debilitated despite the fact that this injury was over two years ago. It was felt that the claimant would not be able to return to any heavy labour work.

On November 5, 1999, the independent specialist's report was forwarded to all interested parties for comment. On November 29, 1999, the Appeal Panel met to render its final decision on the matter.


The claimant injured his right knee while in the course of his employment on September 15, 1997. It has been agreed to by all the medical specialists who examined him over the past two years that at the time that he injured his knee he was suffering from a pre-existing condition of osteoarthritis of his right knee. Although it cannot be totally excluded, the Panel notes that there appears to be a majority consensus of medical personnel who have worked on the claimant's file, that on a balance of probabilities, that he did not sustain an ACL injury to his knee at the time of the accident. The Panel accepts this medical finding.

However, at the time of the hearing of this matter, it is also undisputed that the claimant has continued to suffer from right knee problems which began with the accident on September 15, 1997. The independent specialist confirmed as of his examination of the claimant on September 22, 1999, that the claimant had the following current symptomatology:

    "Today on physical examination he had swelling of the right knee with an effusion and increased heat. His range of motion was 0 - 120 degrees. He was ACL deficient with positive Lachman and anterior drawer. His knee checked well in regards to his PCL, MCL and LCL. He had a very minimal pivot shift that did not show any significant instability when doing the pivot shift test. He was tender over the medial joint line and over the patellar undersurface with ballottement and palpation. His right knee had no increased effusion. He had a full range of motion flexing to 140 degrees and having full extension with his ligaments being stable. This gentleman's guadriceps size shows a discrepancy of about 2cm. With the right being smaller than the left.

    X-ray examination from January, 1997 shows that he has significant arthrosis involving the medical lateral compartment of the knee as well as the patellofemoral joint. There is osteophyte formation and the degree of arthrosis seen is obviously long-standing."

We know that the claimant suffered a compensable accident. We also know that he had a pre-existing condition in the area of his body that was affected by the accident. We further know that at least up to his examination by the independent specialist on September 22, 1999, the claimant was continuing to experience significant problems with that same area of his body. The issue for the Panel is thus whether or not the compensable injury aggravated or enhanced the pre-existing condition. This determination must be made given the policy of the WCB on Pre-Existing Conditions. The salient parts of that policy read as follows:

    1. 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 Worker's Compensation Board will accept responsibility for the full injurious result of the accident.
    2. Where a worker has:
      1. recovered from the workplace accident to the point that it is no longer contributing, to a material degree, to a loss of earning capacity, and
      2. the pre-existing condition has not been enhanced as a result of an accident arising out of and in the course of the employment, and
      3. the pre-existing condition is not a compensable condition,

                  the loss of eanring capacity is not the responsibility of the WCB and benefits will not be paid."

This section of the policy must be read in light of the definition section of the same policy which reads as follows:


    1. Aggravation
      The temporary clinical effect of a compensable accident on a pre-existing condition such that the pre-existing condition will eventually return to its pre-accident state unaffected by the compensable accident.
    2. Enhancement
      Where a compensable injury permanently and adversely affects a pre-existing condition or makes necessary surgery on a pre-existing condition.
    3. Pre-existing Condition
      A condition that existed prior to the compensable injury."

This Appeal Panel sought and obtained the opinion of an independent specialist who appears to have thoroughly examined the claimant and reviewed his past history with the WCB. The Panel specifically asked the independent specialist whether or not he could find any evidence of a pre-existing condition and if so whether the pre-existing condition was aggravated or enhanced. The answer of the independent specialist was that "there was indeed a pre-existing condition of osteoarthritis of his right knee and that this condition enhanced his osteoarthritic knee from the point of view that it has not settled and he is still quite debilitated"

Consequently, in keeping with WCB policy and the opinion of the independent specialist, this Panel is of the unanimous view that the claimant is entitled to benefits beyond March 6, 1999 as he has suffered a compensable injury that continues to adversely affect his pre-existing condition of osteoarthritis which may in the long run make surgery necessary (a total knee replacement in the opinion of the independent specialist). The worker's loss of earning capacity has been caused in part by a compensable accident and in part by a non compensable pre-existing condition, or the relationship between the two. According to WCB policy, the ongoing loss of earning capacity is the responsibility of the WCB as long as the loss of earning capacity continues.

Panel Members

K. Dunlop, Q.C., Presiding Officer
A. Finkel, Commissioner
R. Frisken, Commissioner

Recording Secretary, B. Miller

K. Dunlop, Q.C. - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 11th day of January, 2000