The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

The worker is appealing the decision made by the Workers Compensation Board ("WCB") that he was not entitled to benefits beyond April 17, 2013 as his current left knee condition was related to a pre-existing condition and was not aggravated or enhanced by his compensable injury. A hearing was held on January 22, 2014 to consider the matter.

Issue

Whether or not the worker is entitled to benefits beyond April 17, 2013.

Decision

That the worker is not entitled to benefits beyond April 17, 2013.

Decision: Unanimous

Background

On May 20, 2011, the worker injured his left knee when he caught his foot in a skid while preparing water tanks in the back of his truck. On May 26, 2011, the worker was diagnosed with an ACL (anterior cruciate ligament) injury. The worker's claim for compensation was accepted and benefits and services were paid.

On July 21, 2011, the worker was seen by an orthopaedic surgeon with respect to his left knee condition. The orthopaedic surgeon noted that the worker had considerable swelling of his lower leg with indentations from his knee brace. There was a large effusion and tenderness along the medial compartment. Range of motion was limited and the worker appeared to have a positive Lachman. The surgeon noted that x-rays of the knee showed a joint effusion with no associated fractures. The surgeon opined that the worker had an apparent meniscus tear and may have a locked fragment.

On August 5, 2011, the worker underwent an MRI assessment of his left knee which showed a MCL (medial collateral ligament) partial tear and associated bone bruising to the anterior aspect of the lateral tibial plateau and proximal fibula. There was a small partial tear of the popliteus muscle. The ACL and patella were considered normal.

On December 9, 2011 the worker underwent an arthroscopy and was diagnosed with synovitis of the left knee. The operative report also indicated that there were no identified articular cartilage lesions, and no meniscus or obvious ACL tearing.

A WCB medical advisor stated on January 1, 2012, that the extensive synovitis noted in the operative report was not causally related to the effects of the initial workplace injury. The medical advisor commented that inflammatory synovitis or inflammation of the joint lining was typically secondary to conditions such as rheumatoid arthritis. He said that recovery from arthroscopic knee surgery would occur within 6 to 8 weeks.

In February 2012, medical reports indicated that the worker's left knee condition did not improve and a second left knee arthroscopy was performed on February 18, 2012.

On April 20, 2012, a WCB medical advisor documented that he discussed the worker's case with a WCB orthopaedic consultant. In response to questions posed by the WCB case manager, the medical advisor stated:

• The February 18, 2012 arthroscopy noted the presence of "previous medial meniscus tear was identified." The presence of a meniscus tear was not reported on the August 5, 2012 MRI nor was this condition seen at arthroscopy on December 2, 2011. A medial meniscus injury was therefore not attributable to the May 2011 workplace incident.
• The findings at both arthroscopies are suggestive of a condition called pigmented villonodular synovitis (PVNS) which was a proliferative condition of synovium and not known to be related to knee trauma. Other causes of an inflammatory synovitis such as rheumatoid arthritis, idiopathic arthritis or psoriatic arthritis should be considered as possibly causative of the worker's operative findings.
• The treating surgeon noted in follow-up of the second knee arthroscopy that there was no lab or microbiological evidence of a knee infection. This was important to exclude as a complication of the initial arthroscopy or perhaps as a complication of the May 2011 workplace incident.
• There was no apparent relationship to the May 2011 workplace incident.
• All treatments are directed to the effects of a non-compensable condition.

In a physiotherapy report of May 30, 2012, it was recorded that the worker's left knee function was quite limited and there was no improvement with range of motion.

In a consultation report dated August 29, 2012, the treating rheumatologist stated:

"I have found no evidence of a connective tissue disease nor rheumatoid arthritis on historical nor on laboratory grounds. The course of events is in keeping with a logical sequence that began with an injury 2 years ago, hemarthrosis, tendinous and muscular damage, which has not recovered since then."

On October 12, 2012, the WCB orthopaedic consultant noted that the current diagnosis was chronic synovitis of the left knee, and partial ankylosis of the left knee. He said the diagnosis of the workplace injury was based on clinical MRI evidence, a partial tear of the medial collateral ligament and a possible bony contusion. He noted that the original MRI, however, did identify hemosiderin deposition in the synovium which could relate to a traumatic hemarthrosis caused by the compensable injury or a pre-existing condition. He noted from the initial reports that the worker did not seek medical attention for a few days and the description of injury did not suggest a high velocity mechanism. It was felt that there was only a temporal relationship between the compensable injury and the current diagnosis.

The orthopaedic consultant also commented that the anticipated recovery for a knee strain and partial MCL tear would normally be within 6 to 8 weeks. He stated that in spite of the recent opinion by the rheumatologist, the report of the initial arthroscopy did not identify any significant traumatic lesion of the joint, rather an intense synovitis, and the surgical procedure was synovectomy for biopsy and treatment. He noted that the worker denied any previous symptoms in the left knee prior to the compensable injury and as the arthroscopy was performed 4 months after the compensable injury, the synovial changes identified, to some extent, might relate to the compensable injury in the nature of traumatic synovitis.

The WCB orthopaedic consultant referred the worker to an independent rheumatologist for an assessment. In his report dated January 24, 2013, the independent rheumatologist opined that:

"Balancing probabilities, I do not suspect that it is related to the left knee injury incident May 20, 2011. This likely represents an idiopathic monoarthritis affecting his left knee."

On April 4, 2013, a WCB medical advisor stated:

"Two arthroscopic procedures failed to identify any mechanical or traumatic lesions of menisci or articular surfaces. The thickening of the medial collateral ligament, unchanged in two imaging studies may or may not have been related to the compensable injury of this claim, as it is unchanged and was present on the original study, three months post-injury…The claimant's continuing significant loss of function and pain relate to the diagnosis of chronic inflammatory arthritis and do not relate to the workplace injury of May 2011."

In a decision to the worker dated April 11, 2013, the WCB case manager stated: "Given the mechanism of injury and the accepted diagnosis (temporary condition expected to resolve in a short period of time), subsequent tests, exploratory surgery, treatment, WCB medical opinions and specialist opinions it is my opinion that on a balance of probabilities you have recovered from the effects of your compensable injury and that any ongoing symptoms that you may be experiencing are unrelated."

On May 23, 2013, the worker's family physician stated: "Currently he is partially disabled from the left knee injury. [The worker] will benefit from some compensation regarding his work related left knee injury. He never had any pre-existing left knee problems prior to his injury."

On July 10, 2013, the Worker Advisor Office requested Review Office to reconsider the WCB's decision of April 11, 2013. The worker advisor submitted that the referenced medical information demonstrated that the worker developed symptoms of left knee synovitis shortly after the May 20, 2011 twisting injury and these symptoms had persisted throughout the claim. There was no clinical evidence to date to support that there was a systemic cause for the worker's left knee synovitis. It was felt that the evidence predominantly associated the worker's chronic left knee synovitis to the May 20, 2011 injury and that he had not recovered from this condition.

In its decision dated October 16, 2013, it was determined by Review Office that the worker was not entitled to benefits beyond April 17, 2013. Review Office stated that the medical evidence in proximity of the compensable injury was consistent with a left knee strain/sprain and it accepted this as the compensable diagnosis. It felt that the current medical evidence outlined a pre-existing condition of left knee synovitis which was not accounted for in relation to the accident. Based on WCB policy, Review Office found that the compensable injury was no longer contributing to the worker's loss of earning capacity or need for medical aid. The worker's pre-existing condition was not aggravated or enhanced and the pre-existing condition was not a compensable condition. On October 23, 2013, the worker advisor 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 has an accepted claim for a left knee injury. The worker is seeking compensation benefits beyond April 17, 2013. Relevant provisions of the Act include:

• ss. 4(1) provides that 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.
• ss. 39(1) provides that wage loss benefits will be paid: “…where an injury to a worker results in a loss of earning capacity…”
• ss. 39(2) provides that the WCB will pay wage loss benefits until such a time as the worker’s loss of earning capacity ends.
• ss. 40(1) provides that the loss of earning capacity is the difference that the worker's net average earnings before the injury and the net average amount the WCB determines the worker is capable of earning after the accident.

Worker's Position

The worker was represented by a worker advisor who provided a written submission. The worker answered questions from his representative and the panel.

The worker advisor submitted that the worker's ongoing left knee difficulties are related to his May 20, 2011 compensable injury and that he is entitled to coverage beyond April 17, 2013. She noted that

• the worker's family physician said the worker did not have a pre-existing left knee condition prior to the May 20, 2011 injury.
• the worker reported the onset of pain, swelling and loss of range of motion shortly after the May 20, 2011 twisting left knee injury.
• although other left knee conditions were noted on MRI and through arthroscopy, the persisting debilitating condition has been synovitis.
• a rheumatologist concluded that there was no evidence of tissue disease or rheumatoid arthritis and that no inflammation was found in the worker's other joints.

The worker advisor concluded that the worker sustained a twisting injury to his left knee on May 20, 2011 and developed symptoms of synovitis shortly after the incident, that the medical information supports that these symptoms had persisted since the injury, and there is no clinical evidence to confirm that the condition is due to either a systemic or other pre-existing conditions.

The worker described the accident which caused the injury. He said he was filling water tanks on a truck when he caught his left foot in some skids and twisted his knee. He said that he fell and was upside down with his foot caught. Over the next few days his left knee was sore but he was able to continue working. However, it worsened and he went to the local hospital on May 26.

The worker acknowledged that he worked the balance of May 20, a couple hours on May 21 and full shifts on May 23, 24, and 25 plus 11.5 hours of overtime.

Employer's Position

The employer was represented by its Human Resource Manager. The General Manager also attended.

The employer representative advised that the worker did not report the injury to the employer on the day of the incident. She said the employer was first informed of the incident on May 26 when the worker dropped off a doctor's note.

The employer representative advised that she interviewed the worker prior to hiring him and did not note any evidence of medical difficulties. She advised that the accident occurred on the worker's second day of employment with the employer. She provided information on the worker's hours during his first week of employment subsequent to the date of the incident. She also advised that the employer would have accommodated the worker had he been willing to work.

The employer representative said the employer does agree that the worker's current condition is not related to the workplace accident.

Analysis

The worker is appealing the WCB decision that he is not entitled to benefits beyond April 17, 2013. For the worker's appeal to be successful, the panel must find that the worker's medical condition and related loss of earning capacity are due to his workplace accident. The panel was not able to make this finding. The panel finds, on a balance of probabilities, that the medical information does not support a relationship between the worker's injury and his condition after April 17, 2013.

In reaching this decision, the panel notes that the worker underwent surgery on two occasions with different surgeons. The surgeons did not identify any mechanical or traumatic lesions of the menisci on the articular surfaces. The first surgeon reported that "There are no identified articular cartilage lesions, no meniscus tearing, and no obvious ACL tearing." The second surgeon reported "anterior cruciate ligament and posterior cruciate ligament were stable to probe. Lateral compartment was similar with no intervention required." Both surgeons found the knee to contain significant synovitis.

After the two operations, the first surgeon speculated that the cause of the synovitis might be a reactive synovitis or "an underlying inflammatory arthritis, especially in view of the elevated ESR, CRP and rheumatoid factor."

The worker was then assessed by two rheumatologists.

The panel notes that the first rheumatologist who the worker saw concluded that "The course of events is in keeping with a historical sequence that began with an injury 2 years ago, which led to hemarthrosis, tendinous and muscular damage. He has not recovered." The panel notes that the first rheumatologist's opinion is based upon a traumatic injury to the knee; however the surgeons who operated on the knee found no evidence of this.

The independent rheumatologist saw the worker on January 24, 2013. The physician reviewed the laboratory test and examined the worker. He ruled out reactive synovitis and opined that:

"[The worker] has persistent left knee synovitis clinically, with no clear previous history of a ligamentous tear requiring repair. He has had two extensive synovectomies and the limited pathology/histology showed reportedly "chronic synovitis." The exact etiology of this persistent synovitis is unclear. Balance of probabilities, I do not suspect that is related to the left knee injury of May 20, 2011. This likely represents an idiopathic monoarthritis affecting his left knee."

The panel notes that a WCB orthopedic consultant reviewed the file and commented that "Two arthroscopic procedures failed to identify any mechanical or traumatic lesions of menisci on articular surfaces." The consultant opined that "The claimant's continuing significant loss of function and pain relate to the diagnosis of chronic inflammatory arthritis and do not relate to the workplace injury of May 20, 2011."

The panel acknowledges that there is a temporal relationship between the injury and the original swelling, but that the medical evidence does not support a finding that the worker's condition after April 17, 2013 is related to the accident.

The worker's appealed is dismissed.

Panel Members

A. Scramstad, Presiding Officer
A. Finkel, Commissioner
P. Walker, Commissioner

Recording Secretary, B. Kosc

A. Scramstad - Presiding Officer

Signed at Winnipeg this 11th day of February, 2014