Decision #109/11 - Type: Workers Compensation

Preamble

The employer is appealing a decision made by the Review Office of the Workers Compensation Board ("WCB") that held that the worker sustained a personal injury from an accident arising out of and in the course of her employment. A hearing was held on June 7, 2011 to consider the matter.

Issue

Whether or not the claim is acceptable.

Decision

That the claim is acceptable.

Decision: Unanimous

Background

Facts and Evidence:

The worker filed a claim with the WCB that she had injured her left knee while entering the employer's premises to start work on the morning of June 8, 2010. She reported the incident as follows:

"I was going up the steps at work. We have one cement step. My left knee suddenly gave out on me and I collapsed. I didn't fall to the ground. I grabbed onto the door, to prevent myself from falling. This caused me to injure my left knee."

The injury was immediately reported to the employer and the worker sought medical treatment. The family physician who examined the worker on June 8, 2010 documented that the worker was limping and had pain with flexion of the left knee over 90°. The physician diagnosed a left knee strain, ordered x-rays and recommended physiotherapy.

On June 9, 2010, the worker was assessed at a sports medicine clinic. The physical findings documented medial joint line tenderness with painful range of motion with flexion. The diagnosis was a medial meniscus tear of the left knee.

On June 10, 2010 a physiotherapist assessed the worker and also diagnosed a left medial meniscal tear.

X-rays of the worker’s left knee revealed advanced degenerative changes involving the patellofemoral joint and degenerative changes involving the lateral compartment of the knee joint.

On June 22, 2010 the family physician's progress report noted continued pain on flexion over 90° with tenderness over the posterior aspect, medial and lateral aspect of the knee. The diagnosis was knee injury with possible medial meniscus tear and/or ligamentous injury.

The WCB adjudicator accepted the worker’s claim for benefits noting on file that the fall occurred at the employer’s premises and that it was reported promptly and medical attention was sought.

An MRI of the worker’s left knee taken on July 15, 2010 showed severe degenerative change of the patellofemoral articulation, femorotibial chondromalacia and a radial tear over the posterior root of the medial meniscus.

A WCB medical advisor reviewed the file on August 13, 2010 and noted that the radial tear of the left knee medial meniscus may be pre-existing in relation to previous left knee instability or alternatively, the meniscal tear would be consistent with the mechanism of injury reported on June 8, 2010.

A consultation with an orthopedic surgeon was arranged. The orthopedic surgeon reviewed the mechanism of injury and noted that the worker had a significant past history of having multiple patellar dislocations starting as a teenager. The surgeon was of the view that the worker had a left medial meniscal tear and osteoarthritis, particularly of the patellofemoral compartment, secondary to her recurrent patellar dislocations. He recommended a left knee arthroscopy to deal with the meniscal pathology and noted that this would not give the worker a normal knee given the significant arthritic changes. The WCB authorized surgery.

On August 23, 2010, the employer's representative appealed the acceptance of the claim to the Review Office on the ground that the injury did not arise out of the worker’s employment. It was the employer's position that the worker's injury was not caused by any hazard of the workplace but was due solely to her pre-existing degenerative condition and was, therefore, not compensable.

The Review Office asked its medical consultant to review the file in light of the worker’s prior history of knee problems and severe degenerative changes to provide assistance in determining whether the worker’s knee injury was related to the climbing of the stair on June 8, 2010 or whether it was related to the worker’s pre-existing knee instability and degenerative changes.

The worker underwent arthroscopy on November 2, 2010. The arthroscopy revealed that the worker had a left knee flap tear over the posterior third medial meniscus as well as degenerative changes over the patellofemoral and medial tibiofemoral compartments.

The medical consultant provided a report dated November 8, 2010, which reviewed in detail the medical reports on file and the mechanism of injury. In assessing the MRI report that revealed degenerative changes and a radial tear of the medial meniscus of the left knee, the consultant commented that the “radial tear identified in the medial meniscus, is one of that is typically more symptomatic than the horizontal cleavage tears which are primarily degenerative. The MRI here would document a probable acute injury superimposed upon associated degenerative change in the knee joint.”

With respect to the worker’s diagnosis the medical consultant concluded as follows:

“At this time, the most probable diagnosis to account for the claimant’s clinical picture in relationship to the workplace event is an acute radial flap tear to the medial meniscus. The sudden onset of significant pain that lead (sic) to limping, as well as limited range of motion, coupled with provocative meniscal tests, the x-ray changes, the MRI, as well as the findings at arthroscopy, all indicate a probable diagnosis of an acute tear of the medial meniscus. The claimant also has underlying patellofemoral arthrosis, as well as medial tibiofemoral arthrosis. These conditions were probably pre-existing and not caused by the event in question.”

In considering the mechanism of injury, the medical consultant also concluded:

“While weight bearing, in a flexed position going up a stair, there is a significant amount of load greater than body weight going through the compartments of the individuals (sic) knee joint, applying load directly to the meniscus. In a clinical context, it is very common for individuals to present with probable meniscal tears without significant violence, at the age of the claimant. In this matter, there is little doubt that the acute presentation of the knee joint transpired at the time of the event in questions, as detailed by the claimant, and multiple caregivers. The findings of the claimant’s knee joint are uniformly suggestive of this diagnosis, and no other diagnosis. In this matter, I would state that the diagnosis of radial tear of the medial meniscus, is consistent with a mechanism of injury of ascending a stair.” [emphasis added]

The medical consultant also provided an opinion as to whether the worker’s underlying degenerative changes in the knee joint caused it to give way. The consultant was of the opinion that the degenerative changes would not normally cause the knee to give way, stating as follows:

“The MRI documents that the claimant had probable pre-existing degenerative change at the patellofemoral articulation, as well as the femorotibial articulation. These conditions do not normally lead to the knee joint giving way. Giving way is usually due to an acute meniscal injury, underlying instability from anterior cruciate ligament deficiency or a loose body. The claimant has not manifested anterior cruciate ligament deficiency or a loose body.”

The medical consultant’s opinion was forwarded to the employer's representative for comment. A response from the representative was received dated December 1, 2010. No additional medical information was provided by the employer.

On December 13, 2010, the Review Office held that the claim was acceptable. The Review Office accepted the opinion of the WCB medical consultant that the worker's pre-existing condition of the left knee would not normally lead to the knee joint giving way and that the diagnosis of a radial tear of the medial meniscus was consistent with a mechanism of injury of ascending a stair. The Review Office concluded that the worker was entering the employer’s premises in order to perform her work duties and therefore the injury arose out of and was causally connected to the employment.

The employer appealed the Review Office's decision to the Appeal Commission and a hearing was held.

Reasons

Analysis:

Under subsection 4(1) of The Workers Compensation Act, an injury is compensable, if it is the result of an accident arising out of and in the course of employment.

As noted in WCB Policy 44.05.20, General Premises, “arising out of the employment” is mostly concerned with whether the activity giving rise to the injury is causally connected to the employment and “in the course of employment” refers to an injury which occurs within the time of employment, at a location where the worker may reasonable be, and while performing work duties or an activity incidental to employment. The policy further states that “in the course of employment” is not limited to the actual tasks or hours of work and that “generally, a worker is in the course of employment upon entering or departing the employer’s premises, at a time reasonably close to the beginning or end of work, and using an accepted means of entering and leaving the employer’s premises, all in relation to performing activities for the purposes of the employer’s business”.

WCB Policy 44.05, Arising Out Of and in the Course of Employment, also clarifies the concept of “arising out of and in the course of employment”. It states in part that “generally, an injury or illness is said to have “arisen out of employment” if the activity giving rise to it is casually connected to the employment – that is, if it is caused by some hazard which results from the nature, conditions or obligations of the employment.”

In the case at hand, the worker was entering the employer’s premises in order to begin her day at work when she sustained an injury to her left knee climbing the stair at the front door. The panel is of the opinion that when the worker ascended the stair to enter the building she was performing an activity incidental to her employment. The panel finds the worker was entering the employer's premises at a time reasonably close to the start of her shift and was using an accepted means of entering the building. The accident occurred “in the course of employment”.

The issue before this panel is whether the worker’s left knee meniscal tear also arose out of her employment in the sense that it was causally connected to her employment or activities incidental to her employment. The panel is of the opinion that when the worker ascended the stair to enter the building she was performing an activity incidental to her employment.

The WCB will not cover injuries resulting solely from the effects of a worker’s pre-existing condition. The panel must determine whether the work-related activity of climbing the stair was the probable cause of the worker’s meniscal tear or whether this injury solely related to the effects of the worker’s pre-existing degenerative knee condition.

The panel is of the view that in the circumstances of this case, the worker’s injury was caused, on the balance of probabilities, by the action of ascending the stair and not by her degenerative knee condition. We have reached this conclusion for the following reasons:


  • The medical consultant described the hazard or risk of injury that may be present when climbing a stair and that may result in a meniscal tear. The consultant explained that the shifting of weight in a flexed position going up a stair places a significant amount of load greater than body weight on an individual’s knee joint, which is applied directly to the meniscus. The medical consultant was of the opinion that the radial tear of the medial meniscus was consistent with a mechanism of injury of ascending a stair.
  • The medical consultant also explained that the radial tear identified on the MRI in the medial meniscus, is one that is typically more symptomatic than the horizontal cleavage tears which are primarily degenerative. In his opinion, the sudden onset of significant pain that led to limping, the limited range of motion, the MRI, and the findings at arthroscopy, all indicate a probable diagnosis of an acute tear of the medial meniscus;
  • The medical consultant considered the worker’s degenerative knee condition and whether it may have been the cause of the worker’s knee giving way at the time of her injury. The medical consultant indicated that the worker’s underlying degenerative changes would not normally lead to the knee joint giving way and that the probable cause of her knee giving way was the acute meniscal injury.

The panel notes that the employer did not provide any medical evidence contradicting the conclusions reached by the medical consultant.

The panel accepts the opinion of the medical consultant and, in light of all of the medical evidence and circumstances of this case, determines on a balance of probabilities that the worker’s left knee meniscal tear was causally connected to her employment activities. The panel therefore finds that the worker’s injury arose out of and in the course of her employment. The claim is accepted and the employer’s appeal is denied.

Panel Members

M. Thow, Presiding Officer
C. Devlin, Commissioner
P. Walker, Commissioner

Recording Secretary, B. Kosc

M. Thow - Presiding Officer

Signed at Winnipeg this 29th day of July, 2011

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