Decision #93/13 - Type: Workers Compensation

Preamble

The worker is appealing the decision made by the Workers Compensation Board ("WCB") that there was no relationship between his 1994 compensable accident and his total knee replacement and therefore he was not entitled to further benefits. A hearing was held on May 30, 2013 to consider the matter.

Issue

Whether or not the worker is entitled to further benefits.

Decision

That the worker is not entitled to further wage loss or medical aid benefits.

Decision: Unanimous

Background

On October 21, 1994, the worker slipped on an ice-covered bridge and hyper-extended his left knee and twisted his back. The worker reported that the pain in his knee went away but then it returned and progressively became worse. On October 28, 1994 he reported the accident to his employer and later sought medical attention in May 1995. On August 1, 1995 the worker underwent surgery for the excision of a bipartite patella fragment of the left knee.

On February 9, 1996, the WCB's Review Office accepted that the worker injured his left knee on October 21, 1994 and that his claim for compensation was acceptable. It did not, however, accept that the worker's time loss and subsequent surgery of August 1, 1995 were related to the October 21, 1994 accident.

On September 4, 1996, the worker's claim was the subject of an Appeal Commission hearing and the appeal panel accepted that the August 1, 1995 surgery and resulting time loss was related to the injury of October 21, 1994. The appeal panel considered the following opinion of the treating orthopaedic surgeon in making its decision:

In my opinion, [the worker] did have a bipartite patella and based on the history provided of not having any previous symptoms until his hyperextension injury at work, I think the most likely explanation is that he did damage the synchondrosis between the 2 patellar fragments and this did not heal with conservative management, therefore, the bipartite patella was excised on August 1, 1995.

My opinion is based on the history as provided to me by [the worker] that he did not have any symptoms prior to his hyperextension injury at work and, therefore, in my opinion his knee symptoms were directly related to the work injury.

The appeal panel also considered the comments made by a WCB orthopaedic consultant dated November 10, 1995 that: "A hyperextension injury could but not likely damage the synchondrosis between the 2 patella ossifications…"

On August 12, 2003, the worker underwent further surgery to his left knee. The WCB was not contacted or informed about this surgery at the time. The postoperative diagnosis was a degenerative medial meniscal tear, Grade 4 chondromalacia medial tibial plateau, Grade 3 chondromalacia femoral condyle, Grade 2 chondromalacia.

In May 2012, the worker advised the WCB that he required a total knee replacement and that it was related to the effects of his 1994 compensable injury. The WCB then obtained information from the treating surgeon regarding the worker's left knee condition. The information was reviewed by a WCB orthopaedic consultant on August 1, 2012 to determine whether or not there was a relationship between the total knee replacement and the compensable accident. The consultant's responses were as follows:

  • the diagnosis of the workplace injury was aggravation of a left patellar synchondrosis at the site of a congenital bipartite patella. This diagnosis proposed by the treating orthopaedic surgeon was supported by the WCB Appeal Commission.

  • a return to pre-injury functioning would be expected following surgery of the separate lateral ossification centre of the left patella on August 1, 1995.

  • the diagnosis requiring surgery on August 12, 2003 and on February 13, 2012 was osteoarthritis ("OA") of the left knee. There was now a left total knee arthroplasty of the posterior stabilized type carried out on June 7, 2012.

  • the current diagnosis was not the result of the October 21 injury on balance of probabilities.

  • the degree of OA of the left knee was documented in the surgeon's report of February 13, 2012 where limited range of motion in a few degrees of standing varus were noted.

  • the pre-existing conditions were the anatomic variant of congenital bipartite left patella and a degenerative joint disease of the lateral femoral condyle. The latter would be the expected result of excessive friction between the broad lateral extension of the patella and the lateral part of the patella-femoral joint.

  • there was no objective medical evidence that the injury to the patella nor the surgery to remove the lateral portion of the patella would have initiated the degenerative process in the weight-bearing portion of the medial knee compartment.

  • the surgical procedures carried out on August 12, 2003 and June 7, 2012 were not related to the compensable diagnosis on balance of probabilities.

By letter dated August 24, 2012, the worker was advised that the WCB was unable to accept responsibility for any costs related to his left knee as the WCB was unable to establish a relationship existed between his left knee difficulties and the work injury of October 21, 1994. The decision was based on the opinion expressed by the WCB orthopaedic consultant dated August 1, 2012.

On September 7, 2012, the worker outlined his position that the deterioration in his left knee (O/A, the broken/separated bipartite patella, the cartilage damage, the swelling and pain) was the result of his compensable workplace accident of October 1, 1994. The worker indicated that he never had a knee problem until the workplace accident. He never had arthritis in any part of his body until the accident and surgery of August 1, 1995 and a number of years later it began to manifest in his left knee. The worker felt that there was no logical or reasonable explanation for the deterioration of his knee other than the workplace accident and the resulting surgery.

On October 12, 2012, a WCB case manager advised the worker that she reviewed the report submitted by the treating orthopaedic surgeon, but felt that the report did not provide any new information regarding the status of his left knee. The case manager indicated that she was unable to change her previous decision that a relationship had not been shown to exist between the 1994 work injury and his current left knee difficulties. On November 2, 2012, the worker appealed the decision to Review Office.

On December 6, 2012, the employer's representative indicated that the WCB's orthopaedic consultant provided a pathophysiological explanation to support that a relationship did not exist between the total knee replacement and the original incident of October 21, 1994. He said there was no qualified medical opinion to the contrary and that the case management decision of August 24, 2012 should be upheld by Review Office. The worker provided rebuttal arguments to the employer's submission on December 17, 2012.

On January 16, 2013, Review Office determined that the worker was not entitled to further benefits. Review Office referred to specific file information to support that the degenerative changes in the worker's knee were not related to his compensable accident and that the torn meniscus contributed in a comparatively insignificant way to the need for the total knee arthroplasty. On February 15, 2013, the worker appealed Review Office's decision to the Appeal Commission and a hearing was arranged.

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. The worker's entitlement to benefits will be determined by the wording of the Act as it appeared at the time of his workplace accident in October 1994.

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 38(2) provides that where the board determines that a worker has suffered an impairment, it shall pay a lump sum impairment award to the worker.

Subsection 39(1) of the Act provides that wage loss benefits will be paid: “…where an injury to a worker results in a loss of earning capacity…” 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 ends, or the worker attains the age of 65 years.

Worker’s position

The worker was self-represented at the hearing and provided the panel with an extensive written submission which included some medical literature. The worker provided specific comment and points of rebuttal on several portions of the Review Office decision. The worker's overall position was summarized in his summation which stated:

The claimant had a workplace accident on October 31 (sic), 1994 and as a result, suffered trauma to his knee. He was diagnosed by three doctors as having torn his meniscus and damaged (fractured/separated) his patella. The patella was found by way of x-ray at HSC to be a bipartite patella, which, unbeknownst to him, he had been born with. The damage to the patella was considered a fracture or "damage to the synchrondrosis" of the bipartite patella. Subsequently, the piece of bone had to be removed surgically, and the remaining patella repaired. This sequence of events and resulting surgery were recognized and accepted by the Appeal Commission on September 4, 1996.

Since the accident there has been a deterioration in the claimant's knee which must be seen as a natural progression from the trauma to the knee as a result of the workplace accident in 1994 to the development of secondary osteoarthritis in the knee joint, to the deterioration of the knee joint, to the final phase where he had to undergo a total knee joint replacement. The accident occurred on October 31 (sic), 1994. The claimant continued to walk on the damaged leg (knee) and carry out his day-to-day routine, all the while, unbeknownst to him, further damaging and causing further deterioration to his knee. Due to circumstances beyond his control, the claimant was not operated on until August 1, 1995, a total of nine months later.

The worker submitted that there had been no evidence of osteoarthritis in his knee at the time of the original accident and that the osteoarthritis developed as a result of the trauma caused by the workplace injury. It was a progressive set of events which developed from the accident until the time of the knee replacement surgery. There was no other reason for the worker to have arthritis in his left knee except for the accident. He should therefore be entitled to further benefits.

Employer’s Position

A representative from the employer appeared at the hearing. The employer's position was that, on a balance of probabilities, the preponderance of evidence failed to establish the necessary nexus between the worker's knee replacement and the compensable accident of October 21, 1994. It was noted that the medical documentation had been reviewed by a WCB orthopaedic consultant who indicated that on a balance of probabilities, the surgical procedures of August 12, 2003 and June 7, 2012 were not related to the compensable diagnosis. In his pathophysiological explanation, the consultant attributed the need for the surgeries to osteoarthritis. There was no qualified rebuttal of this medical opinion on file. It was also noted that the worker erroneously submitted that his workplace injury was diagnosed and accepted by the Appeal Commission as a torn meniscus and a damaged synchondrosis of a bipartite patella. The employer noted that only the surgery relative to the bipartite patella was accepted, with no reference to a meniscal tear at that time.

With respect to the meniscal tear, the employer noted that a May 27, 2003 report from the surgeon described the tear of the meniscus as being degenerative and that the tear did not present itself until greater than 8 years following the October 21, 1994 incident. There were no clinical findings suggestive of a meniscal tear when the worker was treated in July 1995.

With respect to the bipartite patella, the medical opinion on file indicated that following the surgery for excision of fragment on August 1, 1995, a return to pre-injury functioning would be expected.

Overall, the employer's position was that there was no medical opinion on file that would establish a relationship between the knee replacement and the compensable incident and there was no rebuttal of the orthopaedic opinion that a relationship did not exist. It was therefore submitted that the WCB's decision be confirmed.

Analysis

The issue before the panel is whether or not the worker is entitled to further benefits. In order to decide the appeal, the panel must determine the extent of the injury suffered by the worker as a result of the October 1994 accident, and then determine whether he received all the compensation benefits available under the Act. On a balance of probabilities, the panel finds that the compensable injury was limited to excision of his left bipartite patella, and that the worker's subsequent issues relating to a meniscal tear and osteoarthritis were not causally related to the compensable injury. As a result, we find that the worker is not entitled to further wage loss or medical aid benefits.

In coming to our decision, the panel relied on the following:

  • In the September 4, 1996 Appeal Commission decision, the panel accepted responsibility for the August 1, 1995 surgery and related time loss as being related to the October 1994 injury. The injury was confirmed to be a hyperextension type of injury which damaged the synchondrosis between the two patellar fragments of the worker's bipartite patella. A meniscal tear was not part of the accepted diagnosis.
  • The medical opinion on file was that following this type of surgery a return to pre-injury functioning would be expected and there was no objective medical evidence that the hyperextension injury or excision surgery would have initiated the degenerative process in the weight bearing portion of the medial knee compartment.
  • Medical reports indicate that the worker did quite well for three or four years after the 1995 surgery. At the hearing, the worker confirmed that he returned to work and had a functional recovery for the first several years after the surgery. This would suggest that the injury was limited to the bipartite patella.
  • The evidence does not support the finding that a meniscal tear was part of the October 1994 injury. In particular:
    • In the period immediately following the workplace accident, the medical reports do not report findings consistent with a medial meniscal tear;
    • The 1995 surgery was a success and resulted in a functional recovery;
    • A meniscal injury is not referenced in the medical reports until September 22, 1995, almost one year post-accident;
    • The 2003 operative report describes the tear as a degenerative medial meniscal tear (as opposed to an acute tear, which would have been expected if the hyperextension injury caused the tear).
  • The only medical opinion on file addressing the issue of causation is the August 1, 2012 opinion of the WCB orthopaedic consultant. The panel considers the consultant's analysis to be thorough, and there is no contrary medical opinion on file. We therefore accept his conclusion that the surgical procedures of August 12, 2003 and June 7, 2012 were not related to the compensable diagnosis.

Based on the foregoing, the panel finds that the October 21, 1994 left knee injury was limited to a hyperextension injury which resulted in the 1995 bipartite excision surgery. We find that the worker experienced a functional recovery from that injury and his subsequent left knee difficulties resulting in the August 2003 arthroscopy and the June 2012 total arthroplasty were not causally related to the original workplace injury. We therefore find that the worker is not entitled to further wage loss or medical benefits.

The panel notes that in this appeal, the focus was on entitlement to wage loss and medical aid benefits related to the surgeries of August 2003 and June 2012. As outlined above, the panel finds that there is no entitlement in this regard. We do note, however, that the worker's entitlement to a permanent partial impairment award for any residual deficit caused by the bipartite patella excision was never considered by the WCB. There was a comment by the WCB orthopaedic consultant on August 1, 2012 that the "PPI related to the workplace injury would not be rateable" but this was never formally adjudicated by the WCB. The worker is entitled to be considered for potential entitlement in this regard. This is not to say that the worker will be granted a permanent partial impairment award. The panel only notes that this is a benefit to which the worker may potentially have a right which was never considered by the WCB. The worker may request the WCB to follow up with further investigations in this regard.

The worker's appeal is dismissed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
P. Walker, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 25th day of July, 2013

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