Decision #112/21 - Type: Workers Compensation


The worker is appealing the decision made by the Workers Compensation Board ("WCB") that her permanent partial impairment rating has been correctly calculated. A file review was held on July 20, 2021 to consider the worker's appeal.


Whether or not the permanent partial impairment rating has been correctly calculated.


That the permanent partial impairment rating has been correctly calculated.


This claim has been the subject of a previous appeal. Please see Appeal Commission Decision No. 17/20 dated February 14, 2020. The background will therefore not be repeated in its entirety.

The worker has an accepted claim for a medial meniscus tear of her left knee which occurred at work on March 28, 2005. On September 12, 2005, the worker underwent a left knee partial medial meniscectomy and chondroplasty of the medial femoral condyle. Due to further issues, a total left knee arthroplasty was authorized by the WCB on March 29, 2012 and performed June 19, 2012.

On July 11, 2013, the worker's WCB case manager requested that a WCB medical advisor review the worker's file to determine her eligibility for a permanent partial impairment ("PPI") rating and award. On August 6, 2013, the WCB medical advisor opined that the worker had reached maximum medical improvement of her compensable injury and should be assessed for a cosmetic PPI rating and a rating for loss of mobility in her left knee. The WCB medical advisor further opined that the worker had a major pre-existing condition.

On August 21, 2013, the worker attended a PPI examination with the WCB medical advisor. Following that examination, the medical advisor reported a 20 degree difference in flexion between the worker's left knee as compared to her right knee. Combining that with a cosmetic impairment rating of 1.0%, the medical advisor calculated the worker's PPI rating to be 4.6%. Based on what was considered to be a major pre-existing condition, as identified by the medical advisor on August 6, 2013, the medical advisor determined that the worker's PPI rating should be prorated by 50%, resulting in a total recommended PPI of 2.3% whole person impairment. On August 22, 2013, the WCB advised the worker that she was entitled to a PPI rating of 2.3% and a PPI award in the amount of $640.00.

On September 3, 2013, the worker requested that Review Office reconsider the WCB's decision. The worker submitted that she continued to have difficulties with her left knee, despite the total knee replacement, as well as "off and on again" pain in the opposite right-sided hip, particularly going up stairs or inclines/slopes, and asked Review Office to reconsider her PPI rating.

On October 24, 2013, Review Office determined that the worker's PPI rating had been correctly calculated. Review Office accepted the findings of the WCB medical advisor who conducted the PPI examination, as well as the medical advisor's opinion that the evidence on file demonstrated pre-existing degeneration of the left medial meniscus and left medial compartment. Review Office agreed with the PPI rating calculation of 4.6%, and prorating of that calculation by 50%, resulting in a 2.3% whole person impairment.

On April 29, 2021, the worker appealed the Review Office decision to the Appeal Commission and a file review was arranged.


Applicable Legislation and Policy

The Appeal Commission and its panels are bound by The Workers Compensation Act (the "Act"), regulations and policies of the WCB's Board of Directors. As the worker was injured in March 2005, the provisions of the Act which were in effect at that time are applicable.

Subsection 4(9) of the Act provides that the WCB may award compensation in respect of an impairment that does not result in a loss of earning capacity.

Subsection 38(1) of the Act provides that the WCB "shall determine the degree of a worker's impairment expressed as a percentage of total impairment." Subsection 38(2) provides a scale for the value of lump sum awards based on the degree of impairment, which is adjusted on an annual basis and published in a regulation.

The WCB Board of Directors has established Policy, Permanent Impairment Rating Schedule (the "PPI Policy"), to be applied for accidents occurring between January 31, 2003 and December 31, 2014, inclusive. Impairment benefits are calculated under the PPI Policy by determining a rating which represents the percentage of impairment as it relates to the whole body.

The PPI Policy provides that the degree of impairment will be established by the WCB's Healthcare Services Department in accordance with the Policy, and that whenever possible, and reasonable, impairment ratings will be established strictly in accordance with the schedule which is attached as appendix A to the PPI Policy.

Appendix A to the PPI Policy provides that permanent impairment from a workplace injury is measured by: loss of a part of the body; loss of mobility in the joints; loss of function of any organs of the body identified in the schedule; and cosmetic deformity of the body.

For injuries to lower extremities, Appendix A provides that:

The impairment rating for partial loss of movement or function resulting from direct injury or related surgical procedures…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.

Appendix A also allows for a cosmetic rating for disfigurement. The rating for disfigurement is done by the WCB's Medical Department and the degree of disfigurement is determined on a judgmental basis. To maintain consistency in awards for disfigurement, and to make the awards as objective as possible, the Medical staff makes reference to a folio of previous disfigurement awards.

The WCB Board of Directors also established Policy, Pre-Existing Conditions (the "Pre-Existing Policy"), for decisions on or after June 23, 1992. The Pre-Existing Policy describes how a pre-existing condition may affect entitlement to benefits, and provides as follows with respect to an impairment award:


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.


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 was self-represented on the appeal. The worker provided her Appeal of Claims Decision Form on April 29, 2021, and a further written submission on May 12, 2021 in support of her appeal.

The worker's position, as indicated in her written submissions, was that the 2.3% PPI rating was incorrect, was contrary to the medical information on file, and was inconsistent with WCB policy.

In her Appeal of Claims Decision Form, the worker noted she was appealing the reduction in her PPI rating from 4.6% to 2.3% due to her having a pre-existing condition. The worker submitted that her PPI rating should not have been reduced on this basis. She attributed the reduction of her PPI rating to a decision by her WCB case manager to decrease the employer's responsibility on the claim by 50%, stating that the worker had a "pre-existing injury." The worker submitted that this was an improper decision by the case manager, who was not a medical professional, and that this decision affected her PPI rating.

The worker insisted that there was no pre-existing condition. She submitted that she was legitimately injured at work in 2005 during the course of her evening shift, and that the subsequent "relapse" of that original injury resulted in total knee replacement surgery in 2012, which was approved by the WCB and related to the workplace injury. The worker indicated there were letters and reports on file which stated there was no pre-existing condition and her injuries were only due to the workplace incident.

The worker also noted in her Appeal of Claims Decision Form that due to the total knee replacement or implant on her left knee, that knee could only reach a maximum flexion of 120°, resulting in a range of motion which was 20° less than for a normal knee of 140°. In her further submission on May 12, 2021, the worker noted that the chart in the PPI Policy referring to loss of movement/function indicated flexion of 150°, which she submitted was for a normal and non-operated knee. The worker submitted that there was therefore a 30° difference in flexion between her left knee with the implant as compared to the normal, non-operated knee which could reach to 150°, and that this difference of 30° should have been taken into account and resulted in a higher PPI rating.

Employer's Position

The employer did not participate in the appeal.


The issue on this appeal is whether or not the permanent partial impairment rating has been correctly calculated. For the worker's appeal to be successful, the panel must find that the Act and/or WCB policy were not properly applied in establishing the worker's PPI rating. The panel is unable to make that finding, for the reasons that follow.

In terms of the calculation of the worker's PPI itself, the panel notes that the rating of 4.6% as assessed by the WCB medical advisor was comprised of a cosmetic rating (due to scarring of the left knee) and a rating of 3.6% attributable to a loss of mobility in the worker's left knee. The panel further notes that the worker did not contest the cosmetic portion of that rating at 1.0%.

With respect to the calculation of the loss of mobility in the worker's left knee, the panel reviewed the notes of the WCB medical advisor who performed the PPI assessment on August 21, 2013. The panel finds that the medical advisor appears to have examined the worker properly and made appropriate measurements as contemplated under the PPI Policy. The panel further finds that the impairment rating of 3.6% for loss of range of motion was calculated in a manner which was consistent with the process outlined on page 12 of the PPI Policy for calculating the impairment rating for loss of range of motion.

While the worker argued in her most recent submission that reference in the Policy to flexion of 150° for a normal and non-operated knee should have been taken into account, and a difference of 30° in flexion between her impaired left knee and that 150° should have been recognized and resulted in a higher rating for loss of range of motion, the panel is unable to accept that argument. The WCB medical advisor also measured the worker's right or symmetric knee during the PPI examination, noting flexion on the right knee of 140°, and a difference of 20° in flexion between the worker's two knees. The panel notes that the evidence does not support, nor was it suggested, that the worker's right knee was somehow impaired or other than normal. In the circumstances, the panel finds that comparison of the actual measurement of the range of motion of the worker's right and left knees as representing the loss of range of motion in the left knee and degree of whole person impairment was reasonable and appropriate and consistent with the PPI Policy.

With respect to the 50% reduction of the PPI rating on account of a major pre-existing condition, the panel is satisfied that the evidence supports that the worker had significant degenerative changes to her left knee prior to the workplace injury. The panel is of the view that such a conclusion is supported by:

• An April 22, 2005 MRI of the worker's left knee, showing chondromalacia involving the lateral patellar facet and myxoid degeneration involving the medical meniscus.

• The September 12, 2005 Operative Report of arthroscopic surgery on the worker's left knee, which involved a partial medial meniscectomy and chondroplasty of the medial femoral condyle. Findings in that report included significant grade 2 to 3 chondromalacia and minor tears and thinning of the medial meniscus, and the postoperative diagnoses were minor degenerative medial meniscal tear and grade 2 to 3 chondromalacia medial femoral condyle.

The panel notes that our view in this regard is consistent with the notes of a call-in examination of the worker on November 10, 2005 with a WCB medical advisor and a WCB physiotherapy consultant, who opined that subsequent to her March 28, 2005 injury, the worker "underwent MRI and arthroscopy which revealed mostly degenerative changes with chondromalacia and degenerative tears of the meniscus. Both of these findings would be considered to have pre-existed her injury and were likely aggravated by her injury."

The panel also places weight on the further WCB medical advisor's August 6, 2013 review of the worker's file in connection with the PPI assessment, where he noted that "Imaging studies as well as findings at arthroscopy demonstrated evidence of pre-existing degeneration of the left medial meniscus as well as left medial compartment." The panel agrees with and adopts the WCB medical advisor's analysis of the evidence and conclusion based on his review, that there was considered to be a major pre-existing condition that warranted the 50% prorating. As a result, the panel finds that the worker's PPI rating of 4.6% for loss of range of mobility and scarring in the left knee, was properly reduced by 50%, to 2.3%.

The panel also considered the calculation of the monetary amount of the PPI award and is satisfied that it was correctly calculated at $640.00 in accordance with the scale for the value of lump sum awards under subsection 38(2) of the Act, as adjusted by regulation.

In arriving at our decision, the panel acknowledges the worker's submissions with respect to the impact her injury has had on her life, including with respect to loss of wages or income and pain she experiences as a result of her injury. The panel notes, however, that an impairment award is not related to, or a substitute for, loss of earning capacity, nor is it intended to compensate a worker for pain or suffering resulting from an injury.

In conclusion, the panel finds that the Act and WCB policy were properly applied in establishing the worker's PPI rating. The panel therefore finds that the worker's permanent partial impairment rating has been correctly determined.

The worker's appeal is dismissed.

Panel Members

M. L. Harrison, Presiding Officer
J. Peterson, Commissioner
R. Ripley, Commissioner

Recording Secretary, J. Lee

M. L. Harrison - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 17th day of September, 2021