Decision #124/09 - Type: Workers Compensation

Preamble

This appeal deals with a decision made by Review Office of the Workers Compensation Board (“WCB”) which determined on December 11, 2008 that the worker’s left knee difficulties and subsequent surgery were not related to his compensable work event of May 29, 2007. The worker disagreed with the decision and an appeal was filed with the Appeal Commission through the Worker Advisor Office. A hearing was held on May 6, 2009 to consider the matter.

Issue

Whether or not the worker’s ongoing left knee difficulties and subsequent surgery are related to the May 29, 2007 compensable injury.

Decision

That the worker’s ongoing left knee difficulties and subsequent surgery are not related to the May 29, 2007 compensable injury.

Decision: Unanimous

Background

The Worker’s Accident Report filed on September 25, 2007 indicated that the worker suffered an injury to his left knee on May 29, 2007 from the following work related accident:

“I tripped over a hose by the pressure washer and twisted my left knee…my foot caught in a coil of the hose; I stumbled and tried to regain my balance so I was kinda staggering and stepping on the hose again (hose is about 40 feet long and was coiled back and forth)…My other knee was bothering me at the time but the left knee was particularly bothering me…I saw the surgeon August 13. He said I have fluid pockets and some torn cartilage in both knees and that I will need orthoscopic (sic) surgery at some point.”

The Employer’s Accident Report filed on September 28, 2007 indicated that the worker tripped on a pressure washer hose and fell to his knees. The worker reported that his left knee hurt a bit but that it was healing and he did not think medical attention would be necessary. On September 25, 2007, the worker advised that he did not think he had damaged his knee initially but he was seeing a doctor and surgeon and surgery was recommended on both knees.

Medical reports on file indicated the following:

· May 30, 2007 – the family physician indicated that the worker “called back due to abnormal x-ray” and that he had some swelling to the left knee. An MRI was ordered.

· August 13, 2007 – an orthopaedic specialist reported that the worker had chronic knee pain and that he had previous arthroscopic surgery to his left knee due to arthritis. He noted that examination of the left knee revealed medial crepitus and lack of range of motion from 0 to 100 degrees only. He noted that an MRI scan showed distinct osteoarthrosis on the left knee. An arthroscopy was suggested.

· June 25, 2007 – an MRI on both knees was performed and radiological results for the left knee were reported as : “Multi-compartment OA [osteoarthritis] with multi-septated joint effusions and vertical tears of the posterior horn of the medial meniscus along with truncation of the medial meniscus secondary to advanced OA changes. Chondromalacia of the patellofemoral and medial femorotibial compartments is demonstrated.”

· October 17, 2007 surgical report – the post-operative diagnosis was “Osteoarthrosis Medial Compartment. Medial Meniscus Tear. Tumour Capsule and Synovium Left Knee.”

· October 29, 2007 – the family physician reported that the worker had been followed quite regularly for his osteoarthritis condition but at some stage in 2007 had mentioned there was an actual incident that occurred at his previous place of employment where he thought he tripped over something.

On November 8, 2007, the worker was advised that the WCB accepted responsibility for the workplace event of May 29, 2007 based on the confirmed report from his employer but no responsibility would be accepted for his ongoing knee difficulties beyond that date. The adjudicator found that the worker’s pre-existing left knee condition was contributing to his current symptoms, that his disability due to surgery was also the result of his pre-existing condition and that there was no evidence to support an aggravation due to the May 29 workplace event.

Subsequent to the November 8, 2007 adjudicative decision, a report was received from the orthopaedic surgeon for an examination that occurred on December 3, 2007. He noted that the worker was seen in follow up of his left knee arthroscopy. He stated that he and the worker had a long discussion regarding the acute onset of his left knee problems in relation to his compensable injury. The surgeon noted that on the day of injury, the worker’s foot got caught in a loop of a pressure hose and he stumbled with a rotatory injury to his left knee. He stated, “There is no doubt that this can cause an acute tear which has nothing to do with the underlying mild arthritis that he had. To my mind, therefore, this is an acute injury followed by the meniscus cyst which developed over a few months and this is certainly due to the injury as described to me.”

In a further decision dated December 18, 2007, the worker was advised that the new medical information submitted by the surgeon did not alter the previous WCB decision. The adjudicator stated in part that the “underlying mild arthritis” noted by the surgeon in his report of December 3, 2007 was contrary to the official findings on x-ray, CT scan and post operative surgery which described the worker’s knee condition as “advanced/severe osteoarthritis”. After considering the severity of the worker’s knee condition, the adjudicator found that his knee symptoms were consistent with his existing chronic problem and that it was unrelated to the workplace event of May 29, 2007.

On January 18, 2008, a worker advisor submitted that the December 3, 2007 orthopaedic report supported that the mechanics of the May incident could have resulted in an acute tear of the worker’s left knee. She submitted that the worker’s increased left knee symptoms from the May 2007 incident until surgical repair in October 2007 provided evidence of a causal relationship and that the WCB should be responsible for the worker’s surgical treatment and recovery period.

A submission was received from the employer’s representative dated May 27, 2008. It stated that the employer was not in dispute that a compensable accident took place in May 2007 but was of the view that the accident was minor and would not cause any significant disability.

Prior to considering the worker’s appeal, Review Office requested and obtained additional medical information from the orthopaedic surgeon which was reviewed and commented on by a WCB senior medical advisor on November 10, 2008. The medical advisor stated:

“…I would state that this claimant’s most probable diagnosis is severe bilateral osteoarthrosis of the knees, mostly affecting his medial knee joint compartments. It is probable that this has been a long-standing condition for him. I would state that the claimant’s symptomatology is more probably emanating from the osteoarthrosis, than it is from the meniscal pathology identified at arthroscopy, or on the MRI…The large tumor was also probably causing some of his symptoms and it was not probably related to the compensable event. In general, the severe osteoarthrosis as described in this claimant’s knees would be symptomatic as would be the synovial tumor and these conditions would be his pain generator in relationship to his knee joint….In my opinion, I do not believe the claimant’s surgery was related to the compensable event in question.”

In a decision dated December 11, 2008, Review Office confirmed that the worker’s ongoing left knee difficulties and subsequent surgery were not related to his compensable injury. Review Office indicated in its decision that it gave significant weight to the WCB medical advisor’s November 10, 2008 opinion that the worker’s symptomatology was probably emanating from non-work related pre-existing factors. It found that the medical evidence did not support a causal relationship between the worker’s ongoing left knee difficulties and subsequent surgery to his compensable left knee injury. On January 6, 2009, the worker advisor appealed Review Office’s decision to the Appeal Commission and a hearing was arranged.

Subsequent to the May 6, 2009 hearing, the panel met on several occasions to discuss the case. Prior to rendering a decision on the issue under appeal, the appeal panel obtained additional information from the radiologist who interpreted the June 2007 MRI results as well as from an independent orthopaedic surgeon. On November 10, 2009, the panel met further to discuss the case and rendered its final decision.

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. Subsection 4(1) of the Act provides:

4(1) Where, in any industry within the scope of this Part, personal injury by accident arising out of and in the course of the employment is caused to a worker, compensation as provided by this Part shall be paid by the board out of the accident fund, subject to the following subsections. (emphasis added)

The key issue to be determined by the panel deals with causation and whether the worker’s left knee difficulties and subsequent surgery were required as a result of the workplace accident of May 29, 2007.

The worker’s position:

The worker was assisted by a worker advisor at the hearing. It was submitted that the evidence supports that the worker’s left knee symptoms became increasingly worse following the May 29, 2007 incident and required surgical treatment. The worker described a sharp pain on the inside of the left knee following the accident and this sharp pain subsided following surgical treatment. He is now back to his full regular duties. It was submitted that the sharp pain was the result of an acute injury sustained at work and that the WCB should be responsible for the surgical treatment of the left knee. The report of the orthopedic surgeon was relied upon to support that the mechanism of injury could have caused an acute tear to the knee.

The employer’s position:

A representative from the employer was present at the hearing. It was submitted on behalf of the employer that while there is no dispute that a compensable accident took place, it would not appear that the accident itself caused significant disability. The workplace incident was not the primary cause of the worker’s knee surgery as he had already been receiving treatment for a serious pre-existing knee condition. It was submitted that the eventual surgical procedure would have occurred in any event due to the significant pre-existing osteoarthritis of the affected knee, as well as other degenerative changes in the knee joint. The employer agreed with the WCB’s decision to end responsibility on this claim and to reject responsibility for the surgery.

Analysis:

The issue before the panel is whether the WCB should accept responsibility for the worker’s ongoing left knee difficulties and subsequent surgery. In order for the appeal to be successful, the panel must find that the left knee surgery, which was performed on October 17, 2007, was required because of the knee injury which the worker suffered at work in May, 2007. After reviewing the evidence as a whole, we find on a balance of probabilities that the surgery was not required as a result of an injury sustained in the May, 2007 accident; accordingly, the WCB should not accept responsibility for the ongoing left knee difficulties and subsequent surgery.

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

  • Prior to the workplace accident, the worker already had known osteoarthritis for which he was being followed regularly by his family physician;
  • The August 13, 2007 consultation letter from the orthopaedic surgeon to the family physician indicates that surgery to the left knee was suggested due to more distinct osteoarthrosis on the left knee and fatty changes in the distal femur. Arthroscopy of the left knee was suggested with debridement and removal of multiple loculated cysts in the suprapatellar pouch. The letter describes left knee issues which are typically more associated with osteoarthritis than an acute meniscal tear.
  • The post-operative diagnosis outlined in the surgical report of October 17, 2007 indicates: “osteoarthrosis medial compartment, medial meniscus tear, tumor capsule and synovium left knee.” The panel finds, on a balance of probabilities, that none of these diagnoses can be related to the workplace accident. In that regard, we accept the September 30, 2009 opinion of the independent orthopaedic surgeon which states: “I do not believe it is probable that the pathology, specifically findings of osteoarthritis, degenerative meniscal tear and meniscal cyst, found at the time of surgery, was caused by the incident which occurred at work in May 2007.”

The worker’s position relies upon the treating orthopedic surgeon’s report of December 3, 2007 where he opines that: “There is no doubt that this (the workplace accident) can cause an acute tear which has nothing to do with the underlying mild arthritis that he had. To my mind, therefore, this is an acute injury followed by the meniscus cyst which developed over a few months and this is certainly due to the injury described by me.” The panel has concerns with this opinion on causation for two reasons. First, the panel questions the surgeon’s characterization of “underlying mild arthritis” in the face of the worker’s previous medical history and the same surgeon’s description of “severe osteoarthrosis” in the surgical report. The discrepancy is significant. Second, the panel finds it unlikely that a tumor of that size, which was described as “huge” in the surgical report, could develop in four and a half months. We again rely upon the opinion of the independent orthopaedic surgeon which states: “The cystic meniscus that was removed at the time of surgery is evidence of likely long standing degenerative meniscal pathology.”

Overall, we find that the file information does not disclose evidence which would convince us on a balance of probabilities that the worker suffered an acute meniscal tear or other injury which necessitated surgery when he fell at work in May 2007. We adopt the analysis of the Review Office medical advisor that the pre-existing severe bilateral osteoarthrosis of the knees and the large tumor were probably causing the worker’s left knee symptomatology and that these conditions would be the pain generators in relationship to the worker’s knee joint. We also accept the medical advisor’s opinion that the event in question did not lead to an enhancement or an aggravation of the worker’s underlying severe osteoarthrosis of the left knee joint.

We therefore find that the ongoing left knee difficulties and subsequent surgery are not the responsibility of the WCB. The worker’s appeal is dismissed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
D. Zirk, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 23rd day of December, 2009

Back