The Appeal CommissionThe Workers Compensation Act of Manitoba

Applicable Legislation

Payment of compensation for an impairment and the method for determining the amount of the impairment award are provided for under subsections 38 (1) and (2)of the Act, which reads as follows:

Determination of impairment

38(1) The board shall determine the degree of a worker's impairment expressed as a percentage of total impairment.

Calculation of impairment award

38(2) Where the board determines that a worker has suffered an impairment, the board shall pay to the worker as a lump sum an impairment award in the following amount, for an impairment that is determined by the board to be

(a) 1% or greater but less than 30%: $1,030 for each full 1% of impairment;

(b) 30% or greater: $30,900 plus $1,240 for each full 1% of impairment in excess of 30%.

In accordance with the Act, the Board of Directors enacted WCB Policy 44.90.10.02 Permanent Impairment Rating Schedule (the “Permanent Impairment Policy”) which provides guidelines on how impairment awards are to be calculated. The Policy states:

1. The degree of impairment will be established by the Healthcare Management Services Department of the Workers Compensation Board in accordance with this policy. The degree of impairment established by this Department can only be altered on review and approval by the Executive or Senior Director responsible subject to the normal appeal process.

2. Whenever possible, and reasonable, impairment ratings will be established strictly in accordance with the schedule attached as Appendix A….

4. If a worker had a pre-existing condition the worker is eligible for an impairment award based on the difference between the new combined rating and the rating assigned to the pre-existing condition. The Healthcare Management Services Department will assign a fair rating to the pre-existing condition based on the best information available.

For injuries to lower extremities, Appendix A provides as follows:

Loss of Movement/Functions

The impairment rating for partial loss of movement or function resulting from direct injury or related surgical procedures (including patellectomy and his prosthesis) will be proportional to the amount of movement or function that is lost, based on clinical findings, as a percentage of the assigned ratings for complete joint immobility.

In accordance with the Act, the Board of Directors enacted WCB Policy 44.10.20.10 Pre-Existing Conditions (the Pre-Existing Conditions Policy) which provides guidelines for calculation of impairment awards where there are pre-existing conditions. The Pre-Existing Conditions Policy provides that:

3. IMPAIRMENT AWARD ELIGIBILITY

If a worker is injured as a result of a compensable accident and the injury results in a rateable impairment, the existence of a pre-existing condition will not negate the worker’s entitlement to an impairment award. However, if the worker’s impairment (whether caused by the compensable accident or a surgical intervention made necessary by the compensable accident) is an enhancement of a pre-existing but non-compensable impairment, the worker is eligible for an impairment award based on the difference between the new combined rating and the rating assigned to the pre-existing condition.

4. ASSIGNED RATING FOR PRE-EXISTING CONDITIONS

When it is reasonable to do so, the assigned rating for the pre-existing condition will be based on the impairment rating schedule adopted by the WCB. However, when this is not practical, the assigned rating will be determined as follows:

(a) A pre-existing condition which is deemed to be minor will be assigned a 0% rating.

(b) A pre-existing condition which is deemed to be major will be assigned a rating equivalent to 50% of the total combined impairment rating.

Worker’s Position

The worker disputes the method of calculation of the PPI rating. He submits that the left knee measurements should not have been used as a baseline for establishing a normal range of motion, on the basis that any pre-existing degeneration of the knee joints was likely bilateral, and that the range of motion of his left knee at the time of measurement would not therefore have accurately reflected a normal range of motion.

The worker also disputes the 50% pro-rating of the impairment rating on the basis of a major pre-existing injury. The worker contends that he did not have a pre-existing condition in his right knee, relying upon a report from his orthopaedic surgeon, dated July 27, 2011 wherein the surgeon notes that the MRI of June 5, 2009 showed “…some chondromalacia along the medial femoral/tibial compartment” and opines that this “…could have been the result of the medial meniscal tear.”

Employer’s Position

The employer did not make a submission in response to the worker’s appeal.

Analysis

The sole issue for determination by this panel is whether the worker's PPI award was properly calculated. In order for the worker's appeal to succeed, the panel must find that the terms of the Permanent Impairment Policy were not properly applied to the worker's particular set of circumstances.

The panel has considered the worker's entitlement to an impairment award for loss of movement or function in his right knee. The medical evidence before us indicates a compensable diagnosis of a right medial meniscus tear arising out of the workplace injury of November 25, 2008.

Measurements of the worker’s range of motion in the right knee were taken on February 25, 2011 in the course of a WCB call-in examination of the worker. Based on the information provided by the worker that there was no prior injury or damage to the left knee and the medical evidence on file, the physiotherapy consultant determined that the passive mobility measurement of the left knee was an appropriate comparator for measurement of the mobility of the injured right knee. In other words, the range of motion measurements of the left knee were relied upon as indicating the normal range of motion for this worker for the purpose of calculating the expected range of motion for the right knee.

To calculate the PPI, the difference between the actual range of motion of the worker’s right knee measured in degrees (125 degrees) and the normal expected range of motion for that joint (140 degrees, based on the left knee measurements taken) was calculated. The difference of 15 degrees was then divided into the normal measurement (established from similar measurements of the left knee) with the result that the percentage of deficit in range of motion was calculated at 10.7%. Taking into account that the maximum rating under Appendix A to Policy 44.90.10.02, Permanent Impairment Rating Schedule for a fused knee injury is 25%, the impairment was calculated at 2.7%.

The worker disputes this method of calculation of the rating, on the basis that the left knee measurements should not have been used as a basis for establishing a normal range of motion. The worker instead contends that any pre-existing degeneration of the knee joints was likely bilateral, and that the range of motion of his left knee at the time of measurement would not therefore have accurately reflected a normal range of motion.

The medical evidence available to us does not support the worker’s argument on this point. There is no medical evidence with respect to any damage or injury to the worker’s left knee. There is also no medical basis to assume that degeneration of the knees is bilateral, as suggested by the worker. We therefore find that the left knee was an appropriate comparator for calculation of the deficit from a normal range of motion.

The impairment rating established was then prorated by 50% to reflect a major pre-existing injury to the worker’s right knee, pursuant to the Pre-Existing Conditions policy. This resulted in a total rating of 1.35%.

The worker disputes this reduction in the PPI rating to reflect a major pre-existing injury and points to a recently obtained medical opinion that suggests the chondromalacia along the medial femoral/tibial compartment could be a result of the accepted compensable diagnosis of a horizontal tear in the right medial meniscus.

In raising the argument that this is not a pre-existing condition, the worker is effectively seeking to have this panel add the diagnosis of chondromalacia along the medial femoral/tibial compartment to the previously accepted compensable diagnosis. This question is improperly before us and outside the jurisdiction of this panel to determine, as it has never been adjudicated by the Review Office.

We note that the evidence before us is consistent with the finding that the worker had a major pre-existing condition. In his July 22, 2009 opinion, the WCB medical advisor refers to “pre-existing patellofemoral changes.” In his January 7, 2011 opinion, the WCB physiotherapy consultant also noted “On review of the complete file there is considered to be a major pre-existing condition related to the PPI.”

In the absence of prior adjudication as to whether the worker had a pre-existing condition in his right knee, we must base our decision solely upon the basis of the accepted compensable diagnosis and medical evidence, which supports that the worker had a major pre-existing condition.

Based on the measurements of his right knee range of motion taken February 25, 2011, we are satisfied that the worker's PPI was correctly calculated in accordance with the Act and Policy. We agree with the WCB that 2.7% is the proper rating for the worker's permanent right knee impairment, and that, on the basis of the worker’s major pre-existing injury, this rating was properly reduced by 50% to a total rating of 1.35%.

The panel notes that the award of $1,030.00 correctly reflects the worker's financial entitlement to a PPI award pursuant to subsection 38(2). Subsection 38(2) outlines a set formula for calculation of impairment awards 1% or greater but less than 30%. We are satisfied that applying the formula to the worker's PPI award of 1.35% results in an award of $1,030.00.

The panel therefore finds that the worker's permanent partial impairment award has been correctly calculated.

The worker's appeal is therefore dismissed.