The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

An Appeal Panel review was held on April 7, 2000, at the request of the employer.

Issue

Whether or not there is entitlement to a permanent partial impairment award of 5% for deep vein thrombosis, related to the effects of the June 1990 workplace injury.

Decision

That there is entitlement to a permanent partial impairment award of 5% for deep vein thrombosis related to the effects of the June 1990 workplace injury.

Background

During the course of his employment as a labourer on June 20, 1990, the claimant slipped while getting out of his truck and twisted his left ankle. On June 21, 1990, x-rays of the left ankle revealed minor degenerative changes in the ankle joint with minimal bone lipping. Tiny plantar calcaneal spur was also noted. No other bone or joint abnormality was identified. The initial diagnosis was a left capsular sprain. The claim was accepted by the Workers Compensation Board (WCB) and benefits commenced.

Subsequent medical information revealed that the claimant developed a deep vein thrombosis (DVT) in his left lower leg. On October 10, 1990, a WCB medical advisor indicated that the claimant was disabled from the effects of the compensable injury as well as from the DVT. Restrictions were outlined with respect to standing, walking and sitting. The medical advisor recommended a support bandage or stocking to the left leg to minimize swelling.

On November 15, 1990, a WCB medical advisor was asked to review the file with respect to "...what time frame would apply to restrictions related to CI (compensable injury)". The medical advisor responded that restrictions were outlined mainly for the DVT, which was the result of the compensable injury. He could not comment with respect to time frame, as DVT was an unpredictable prognosis.

On December 24, 1990, the medical advisor was asked, "Further to your comments of 15/11/90, would the DVT be considered an underlying condition that is prolonging the clmt's recovery from his CI?" The medical advisor responded, "DVT is the result of the CI and is the main and possibly only reason for his ongoing disability but this will be protracted and will leave him with some permanent restrictions." The medical advisor went on to indicate that the DVT was now responsible for the claimant's time loss from work and not the ankle sprain.

The case was reviewed again by a WCB medical advisor on January 16, 1991. The medical advisor reported that the twisted ankle was treated with a back slab, bandage and rest. The immobility of the leg and pressure of the slab produced stagnation of blood flow through the leg and this stagnation led to the clot resulting in a DVT. On February 28, 1991, the attending physician stated that the claimant could try and return to work which he did on March 4, 1991.

In July and September 1997, the claimant experienced further difficulties with his left leg while at work. The WCB accepted the recurrences as being related to DVT in the left ankle and to be a sequela of the June 1990 accident.

On September 2, 1999, a WCB impairment awards medical advisor assessed the claimant and a 5% permanent partial impairment was recommended for the deep venous thrombosis of the left leg. On October 8, 1999, Rehabilitation & Compensation Services advised the claimant that the 5% PPI award would be implemented effective November 1997, "the date objective evidence of thrombosis to the peroneal vein was confirmed through venography." On November 17, 1999, the employer appealed the 5% rating decision to Review Office. On November 24, 1999, a union representative, acting on behalf of the claimant, submitted rebuttal argument.

On January 7, 2000, Review Office confirmed that the claimant was entitled to a permanent partial impairment award of 5% for deep vein thrombosis, related to the effects of the June 1990 workplace injury. Review Office stated in its decision that it discussed the employer's submission outlining their concerns and their submitted specialist's report, with the WCB's impairment award medical advisor. The medical advisor noted that his decision to assign a rating of 5% was based upon his clinical findings on September 2, 1999, the November 3, 1997, left leg venogram results and the opinions expressed by a Professor of Surgery, Section of Vascular Surgery, in January 1999.

Review Office believed from the whole of the medical evidence that the claimant developed a deep vein thrombosis as a result of the 1990 compensable injury. WCB policy 44.90.10 that specifically deals with the Permanent Impairment Rating Schedule allowed for a rating of 10% for deep thrombosis of the thigh and leg. As noted by the medical advisor, the evidence suggested thrombosis of the peroneal veins but not of the deep vein above the knee. Review Office considered it reasonable to award the claimant a 5% rateable impairment. On February 1, 2000, the employer appealed the Review Office's decision and a non-oral file review was arranged.

Reasons

The issue in this appeal is whether or not there is entitlement to a permanent partial disability award (PPD) of 5% for deep vein thrombosis (DVT), related to the effects of the June 1990 workplace injury. The relevant subsection of the Workers Compensation Act (the Act) is subsection 40(1) which provides for permanent partial disability resulting from an injury and relevant WCB Policy is Section 44.90.10, Permanent Impairment Rating Schedule, which sets out impairment ratings. The employer is appealing the Review Office decision of January 7, 2000 awarding the claimant a 5% permanent partial impairment award as set out in the issue.

Subsection 40(1) states:

Compensation for permanent partial disability

40(1) Where permanent partial disability results from the injury, the board shall allow periodical payments during the lifetime of the worker sufficient, in the opinion of the board, to compensate for the physical loss occasioned by the disability, but not exceeding 75% of his average earnings.

We find the weight of the evidence, on a balance of probabilities, supports a finding that the claimant is entitled to a permanent partial impairment award of 5% for a DVT of the lower left leg, related to the effects of the June 1990 workplace accident.

The claimant sustained an injury to his left ankle at work on June 20, 1990 and developed a DVT of the left calf as a result of the treatment of his injury. On December 20, 1990 a WCB medical advisor indicated:

"DVT is the result of the C.I. and is the main and possibly only reason for his ongoing disability but this will be protracted and leave him with some permanent restrictions."

On January 16, 1991 the medical advisor further indicated:

" The twisted ankle was treated with a back slab and bandage and rest. Immobility of the leg and pressure of the slab produces stagnation of blood flow through the veins of the leg and this stagnation leads to the clot, hence the DVT."

The claimant suffered a recurrence of the DVT in his left calf at work on September 24, 1997 which was accepted by the WCB. On September 2, 1999, the claimant was assessed by a second WCB medical advisor for a permanent partial impairment award. The medical advisor calculated the award to be 5% for DVT of the left leg, effective November 1997, the date when there was objective evidence of thrombosis in the peroneal vein confirmed by venogram on November 3, 1997.

The WCB medical advisor who assessed the claimant for the permanent partial impairment rating of 5% based his rating on his clinical findings on examination, the objective findings on venogram of the left leg performed on November 3, 1997 and on the opinion of a Professor of Surgery, Section of Vascular Surgery in a report dated January 4, 1999.

We accept the examination findings of September 2, 1999 provided by the WCB medical advisor who assessed the claimant for a permanent partial impairment award and his rationale for the rating recorded in a WCB memorandum to file dated December 17, 1999.

We also note that medical literature submitted by the claimant's union representative in this appeal supports the contention that permanent impairment can result from DVT in the lower legs. In particular we note from the literature:

" Any destruction of the small vein system in the leg will mean that there are fewer channels available for blood to return to the heart. Blood then tends to pool in the leg, leading to chronic swelling of the leg. Alternative channels may develop in the form of varicose veins, which are the large diluted veins just underneath the skin: they represent a transfer to the superficial venous system of the extra load caused by the damaged and occluded deep venous system. Swelling in the leg is complicated by the fact that the blood clots also destroy the one-way valves in the veins. Blood therefore backs up in the leg and worsens the swelling. Once the valves have been damaged by a blood clot, they will never function again, and there is no possible way of repairing them."

WCB Policy 44.90.10 specifically contemplates a maximum rating for vascular impairment of 10% for DVT of the thigh and leg. Venography performed on November 3, 1997, as confirmed by the WCB medical advisor, indicated a degree of opacification of the peroneal veins of the left calf suggestive of a thrombus involving the deep veins and that the deep veins above the knee were normal. Therefore we find a 5% rateable impairment award for DVT of the left calf to be reasonable in the circumstances and deny the employer's appeal.

Panel Members

D.A. Vivian, Presiding Officer
A. Finkel, Commissioner
R. Frisken, Commissioner

Recording Secretary, B. Miller

D.A. Vivian - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 13th day of April, 2000