The Appeal CommissionThe Workers Compensation Act of Manitoba

Preamble

The worker is appealing the decision made by the Workers Compensation Board ("WCB") which determined the worker's job duties did not enhance the pre-existing condition in his thumbs and therefore he was not entitled to wage loss benefits. A hearing was held on April 18, 2013 to consider the matter.

Issue

Whether or not the worker is entitled to wage loss benefits after May 3, 2005.

Decision

That the worker is entitled to wage loss benefits after May 3, 2005.

Decision: Unanimous

Background

On January 27, 2005 the worker filed a claim with the WCB for difficulties he was experiencing with both thumbs which he related to his job duties as a sheet metal mechanic. The date of accident was recorded as being November 1, 2003 and the date the accident was reported to the employer was on July 1, 2004. The worker indicated that the reason for his delay in reporting was because he thought his bilateral thumb problems were related to every day aches and pains. The worker provided the following details of his work duties which he believed caused his injury:

I work three saws (big band saw 268 inches, cut off saw, smaller band saw) and I do a lot of grinding on an air grinder where I am using my thumbs to push down on a small lever.

I do a lot of pushing and cutting on the band saw for the past 30 years. When parts come in and they need to be cut, I use the band saw. I am constantly pushing, twisting, pulling on the parts to put them through the band saw. I use mostly my thumbs to maneuver the parts through the saw blade.

For the past six or seven years, I have been working on the saws and grinder for eight hours a day. For the past two years, I am not on the saws as much but still on a daily basis. Basically I handle a lot of parts while using the saws and grinders.

With respect to the onset of his thumb problems, the worker indicated:

I have been having problems with my thumbs for the past four or five years. For the past two years, the pain has been really noticeable. At first, my thumbs were sore and then it progressed to a constant pain in my thumbs. Both thumbs started to swell with the last two years. My right thumb is bigger than my left thumb.

The Employer's Accident Report dated February 7, 2005 indicated that the worker advised them on January 26, 2005 that he was going to have surgery on both thumbs. The worker reported that his doctor told him that it was a repetitive strain injury related to his work duties.

In a report to the WCB dated February 4, 2005 the family physician noted that the worker complained of problems with his thumbs in May 2002. He said he used his hands all day long grinding, using machinery and holding small pieces of equipment. The physician felt that the worker had osteoarthritis at the base of his thumbs and he was treated with medication. The worker was seen again for his thumb problems in November 2002, June 2003 and August 2003. In June 2004, the worker's thumbs were more swollen and sore, particularly his right thumb. An appointment was then made for him to see a surgeon. After the consultation the worker was booked for surgery.

In a decision dated April 7, 2005, the worker was advised that his claim for compensation was not acceptable as it was felt that his thumb condition diagnosed as osteoarthritis could not be linked to his employment activities or to an accident arising out of and in the course of his employment. The worker disagreed with the decision and an appeal was filed with Review Office. The worker argued that his thumb condition was related to the repetitive nature of his job duties over a 30 year career span.

On May 3, 2005, the worker underwent reconstruction of the right first CMC joint. The post operative diagnosis was pantrapezial osteoarthritis right first CMC joint.

On May 27, 2005, an advocate for the employer asked Review Office to uphold the decision that the worker's claim for compensation was not acceptable. The advocate noted that the x-ray reports on file showed that the osteoarthritis was not limited to the worker's thumbs but also involved both of his wrists, including the trapezio-scaphoid articulation in the right wrist. This suggested that the presence of osteoarthritis was not a sequela or that it arose out of the worker's workplace duties.

Following a review of the worker's appeal, Review Office referred the case back to the adjudicator to arrange for a jobsite visit and videotaping of the worker's job duties.

A WCB rehabilitation specialist performed a work site assessment on June 23, 2005 to assess the worker's employment activities with particular attention to his hand thumb mechanics, weights and sizes of items handled and the repetitive nature of the handling. The specialist's report is on file dated June 30, 2005.

On August 2, 2005, a WCB medical advisor answered questions posed by initial adjudication with respect to the worker's claim. The medical advisor stated that the worker's employment activities did not play a role in the development of his osteoarthritis; that it was possible that the workplace activities caused temporary aggravations during the course of the disease progression; and that the worker's need for surgery was related to the primary disease process of osteoarthritis of the first CMC joints and was not related to his employment activities.

By letter dated September 26, 2005, the worker was advised that the WCB found no causal relationship between his work duties and his diagnosed condition of osteoarthritis in his thumbs. It was felt that the osteoarthritis was a pre-existing condition. The worker was further advised that the WCB would not accept responsibility for the May 3, 2005 surgery or the associated time loss or treatment. The worker was advised that the WCB only accepted responsibility for a temporary aggravation of the osteoarthritis of his thumbs.

On July 26, 2006, the worker's union representative submitted medical information from the worker's family physician and plastic surgeon for consideration by the WCB. The union representative contended that the worker's 25 to 30 year employment as a band saw operator contributed to the degenerative changes in his thumbs and the need for surgical intervention.

In a report to the union representative dated May 3, 2006, the family physician outlined the opinion that the worker's many years of continuous overuse activity of working with heavy tools requiring pressure over the thumbs had put him at risk for developing osteoarthritis of the thumbs. She noted that the worker did not have osteoarthritis in any other joints that were troubling him at the moment.

In a report to the union representative dated May 29, 2006, the plastic surgeon stated that the worker's job involved a lot of heavy lifting, gripping and pinching activities and he also used a number of power and vibrating tools. The surgeon noted that with repetitive lifting and gripping there was always force being exerted across the scaphotrapezial trapezoid joint. This would cause more wear and tear and exacerbation of his symptoms. The surgeon also stated:

Even though it is difficult to prove that [the worker's] workplace activities caused the degenerative arthritis in his wrists, his activities certainly will exacerbate his symptoms.

By definition this is a compensable injury. If [the worker] had a light sedentary desk type job where there was minimal use and wear and tear on his hands and wrists, it is very probable that he would not have developed as severe of symptoms as he did. It is my opinion that [the worker's] underlying condition of degenerative arthritis involving both the scaphotrapezial trapezoid joints of both wrists was certainly enhanced by his workplace activities and therefore should be a compensable injury by the Workers Compensation Board.

On August 24, 2006, the WCB asked the union representative to comment on the work site assessment of June 23, 2005.

On September 11, 2006, the union representative stated that the work site assessment in the worker's opinion was more reflective of his workplace activities over the last several years. He noted that the WCB rehabilitation specialist mentioned that the worker was the primary operator of the number 8 band saw on a daily basis for 6 to 7 years. However, the worker contended that his condition was the result of 25 years or more as the primary band saw operator.

In a letter dated October 16, 2006, the union representative was advised that a final review of the file was completed and that no change would be made to the decision of September 26, 2005.

On June 15, 2007, the worker's union representative asked Review Office to review the worker's claim. The representative indicated that three treating physicians agreed that the worker's bilateral thumb condition was related to his workplace activities. He felt that the worksite assessment did not reflect an accurate description as to what the worker was exposed to during his 25 years or more of employment or how he used his thumbs to operate the machinery.

On August 20, 2007, the employer's representative indicated to Review Office that they concurred with the WCB that the worker had been fairly compensated for an aggravation of a pre-existing disease and that surgical intervention was not a WCB responsibility.

On August 16, 2007, Review Office asked a WCB orthopaedic consultant to comment on whether the medical evidence supported that the worker's pre-existing condition was enhanced by his work duties.

On August 21, 2007, the WCB orthopaedic consultant advised Review Office that the worker's bilateral degenerative arthritis developed over a prolonged period of time and that the etiology of this condition was multi-factorial. He said that repetitive activity with the hands was just one of the many factors that could aggravate the condition or could lead to enhancement of the condition necessitating subsequent surgical intervention. He said it was not necessarily causal for the condition itself.

In a decision dated August 23, 2007, Review Office determined that there was no entitlement to wage loss benefits beyond May 3, 2005. Review Office indicated that it accepted the WCB medical opinions outlined on August 2, 2005 and August 21, 2007. It confirmed that the worker's job duties would have caused the worker to experience pain symptoms in both thumbs and agreed with the decision to accept the claim based on an aggravation of a pre-existing condition. Review Office felt there was insufficient medical evidence to support that the worker's job duties enhanced the pre-existing condition or that the job duties resulted in the need for surgery.

On October 12, 2010, the union representative wrote a further appeal to Review Office noting that the worker had undergone surgery to both thumbs and was away from the workplace from May 3, 2005 to August 8, 2005 and May 25, 2006 to September 12, 2006. He noted that although surgical reconstruction was required, the worker claimed that he did not have full mobility of his thumbs. The worker was requesting a permanent partial impairment award and other applicable compensation. The union representative also provided a medical report from an occupational health physician dated April 29, 2010 to support that the worker's bilateral osteoarthritis condition was work-related.

On November 24, 2010, Review Office determined that there was insufficient evidence to warrant a change in its previous decision of August 23, 2007 and that it accepted the August 2, 2005 opinion of the WCB medical advisor. Review Office noted that the occupational health physician: "indicated that there were some suggestions in the medical literature that workplace factors may be (emphasis mine) associated with the development of osteoarthritis. Review Office is of the opinion this does not constitute sufficient medical evidence to support, on a balance of probabilities, that the worker's job duties were causal in the development of the diagnosed condition or that the job duties enhanced the worker's condition."

On May 29, 2012, the union representative provided Review Office with new medical information to consider dated March 6, 2012. The worker's treating plastic surgeon stated:

…I would partially agree with WCB's view point that his work place activities did not cause his underlying condition of osteoarthritis…However, I would strongly disagree with the opinion that the worker's work place activities only caused temporary aggravations of the disease progress. If [the worker's] workplace activities included repetitive lifting and gripping, pinching, pushing or pulling activities with his hands, it is quite easy to see how this would aggravate and enhance and accelerate his underlying condition…There are obviously external factors that can enhance an underlying condition and cause it's (sic) progression to the point where surgical intervention is required. In [the worker's] case these external factors were his workplace activities. Although [the worker's] duties may not have caused his underlying condition they certainly played a role in the aggravation and enhancement of his condition to the point where he required surgical reconstruction.

In a submission to Review Office dated June 19, 2012, the employer's representative commented that upon review of the report from the WCB's rehabilitation specialist who analyzed the worker's workplace tasks in June 2005, there was no mention made that repetitive lifting or gripping or pinching activities with his hands was required to do the job of a saw operator. The employer concurred with Review Office's previous decision that the worker had been fairly compensated for an aggravation of a pre-existing disease and that benefits related to the surgical intervention beyond May 3, 2005 were not the responsibility of the WCB.

On July 4, 2012, the union representative submitted a response to the employer submission of June 19, 2012.

In a decision dated July 25, 2012, Review Office determined that there was no entitlement to wage loss benefits beyond May 3, 2005 and there was no entitlement to a PPI rating. Review Office agreed that some of the work activities required the worker to have his thumbs in a hyper-extended position and that some of the work activities required some forceful pushing and gripping. It was because of these requirements that the claim was acceptable and it was felt that these duties aggravated the worker's pre-existing condition.

Review Office found that the conclusions made by the plastic surgeon were speculative as it appeared that he did not have detailed information regarding the worker's job duties. There was also no medical evidence to suggest that exposure to vibrations would aggravate or enhance the worker's pre-existing condition of osteoarthritis. Review Office concluded that the information submitted was not sufficient evidence to allow it to change its previous decision. The union representative disagreed with the decision made by Review Office and an appeal was filed with the Appeal Commission. A hearing was held on April 18, 2013 to consider whether the worker was entitled to wage loss benefits beyond May 3, 2005.

Reasons

Applicable Legislation and Policy:

The Appeal Commission and its panels are bound by The Workers Compensation Act (the “Act”), regulations and policies of the Board of Directors.

Under subsection 4(1) of the Act, where a worker suffers personal injury by accident arising out of and in the course of employment, compensation shall be paid to the worker by the WCB.

Subsection 39(1) of the Act provides that wage loss benefits will be paid: “…where an injury to a worker results in a loss of earning capacity…” Subsection 39(2) of the Act provides that the WCB will pay wage loss benefits until such a time as the worker’s loss of earning capacity ends, or the worker attains the age of 65 years.

WCB Policy 44.10.20.10 (the “Policy”) addresses the issue of pre-existing conditions when administering benefits. The Policy states:

The Workers Compensation Board of Manitoba will not provide benefits for disablement resulting solely from the effects of a worker’s pre-existing condition as a pre-existing condition is not “personal injury by accident arising out of and in the course of the employment.” The Workers Compensation Board is only responsible for personal injury as a result of accidents that are determined to be arising out of and in the course of employment.

The Policy further provides:

1. WAGE LOSS ELIGIBILITY

a. Where a worker’s loss of earning capacity is caused in part by a compensable accident and in part by a non compensable pre-existing condition, or the relationship between them, the Worker’s Compensation Board will accept responsibility for the full injurious result of the accident.

b. Where a worker has:

1) recovered from the workplace accident to the point that it is no longer contributing, to a material degree, to a loss of earning capacity, and

2) the pre-existing condition has not been enhanced as a result of an accident arising out of and in the course of the employment, and

3) the pre-existing condition is not a compensable condition, the loss of earning capacity is not the responsibility of the WCB and benefits will not be paid.

The definition portion of the Policy gives the following definitions:

Aggravation: The temporary clinical effect of a compensable accident on a pre-existing condition such that the pre-existing condition will eventually return to its pre-accident state unaffected by the compensable accident.

Enhancement: When a compensable injury permanently and adversely affects a pre-existing condition or makes necessary surgery on a pre-existing condition.

Worker’s Position

The worker was represented by a union representative at the hearing. It was submitted that the worker had been continuously employed since November 1974 and during that time he was the sole band-saw operator for the manufacturing operations of the employer. After 39 years of performing his work duties, he developed bilateral osteoarthritis of the first left and right carpal metacarpal joints. His work using heavy tools put a lot of pressure over his thumbs. The worker's doctors supported the position that exposure to work over many years requiring pressure over the thumbs and overuse activity to this area put the worker at risk for developing an osteoarthritic condition in his thumb joints. Furthermore, the worker did not have any other evidence of osteoarthritis in any other joints which were troubling him. It was submitted that the worker's injuries were a result of his long term occupational exposure as the primary band-saw operator in the employer's workplace. Pursuant to the Act, the worker should be compensated for his injuries and his recovery time away from the workplace.

Employer’s Position

A representative from the employer and an advocate were present at the hearing. It was submitted that the worker was not entitled to further wage loss benefits. The current adjudication on the file was an aggravation of a pre-existing disease process. The identified disease process was osteoarthritis. Osteoarthritis is not caused by workplace activities; however, workplace activities can aggravate the condition. There was very limited epidemiological evidence relating first carpal metacarpal osteoarthritis to work exposure. The occupational health physician's examination referred to clear evidence of osteoarthritic changes in the worker's hips, shoulder, elbows, knees, feet, hands and wrists, thereby indicating that the condition was not limited to the worker's thumbs. It was noted that the worker's evidence was that his band saw work activity decreased over the last two years of his employment. Given the decrease in activity, it was submitted that the need for surgeries was more likely related to the natural progression of the disease rather than the worker's employment activities. It was also noted that the job position allowed the worker to self-pace his activities so he had opportunity to eliminate the repetitiveness of the job task involved. Further, the job did not really involve the activities identified by the plastic surgeon as being ones which would tend to aggravate, enhance and accelerate the underlying condition, namely repetitive lifting, gripping, pinching and pulling.

Overall, it was submitted that the worker's injury was limited to a short term aggravation of osteoarthritis in the first metacarpal joints and that the work duties did not create a need for surgery or a need for wage loss benefits beyond May 3, 2005.

Analysis

To accept the worker’s appeal, we must find on a balance of probabilities that his loss of earning capacity beyond May 3, 2005 was causally related to his job duties. We are able to make that finding.

The panel agrees with the determination by the WCB that the bilateral osteoarthritis in the worker's first carpal metacarpal joints was not caused by his work duties. We agree that the osteoarthritis was a pre-existing degenerative condition which would have been present in the worker's thumbs regardless of his occupation.

The panel also agrees that the worker's job duties as a band saw operator had the effect of aggravating the pre-existing osteoarthritis. At the hearing, there was extensive evidence regarding the manner in which the worker operated the band saw and we are satisfied that when performing his duties, the worker made extensive bilateral use of his hands and thumbs, and that he repetitively gripped, pinched and pushed, often with significant force involved.

The question in this case is whether the aggravation caused by the work duties was so severe as to necessitate the surgeries which were performed in May 2005 (right thumb) and May 2006 (left thumb). If they did, then as per the Policy, the worker's pre-existing condition was enhanced and the worker is entitled to further compensation benefits.

On a balance of probabilities, the panel is satisfied that the natural progression of the worker's pre-existing osteoarthritis was accelerated by his work, such that his two surgeries were required. In coming to this conclusion, the panel places significant weight on the opinion of the treating plastic surgeon, who stated:

Even though it is difficult to prove that [the worker's] workplace activities caused the degenerative arthritis in his wrists, his activities certainly will exacerbate his symptoms. By definition this is a compensable injury: If [the worker] had a light sedentary desk type job where there was minimal use and wear and tear on his hands and wrists, it is very probable that he would not have developed as severe of symptoms as he did.

In this regard, the panel notes the extensive use by the worker of both thumbs in his job duties equivalent to gripping and pinching, in particular while using the band saws. These are factors which had been proposed by the treating plastic surgeon that would tend to aggravate, enhance or accelerate the underlying OA condition.

Our conclusion that the worker's pre-existing condition was accelerated by the work duties is further supported by the fact that the only effective way to treat the aggravation was ultimately to perform the reconstructive surgery on the worker's thumbs. The worker was not able to manage

the pain with conservative treatment while remaining in the workplace. Whenever he tried to perform his work duties, he would experience an increase in symptoms. It is notable that the worker's evidence was that his symptoms diminished when he went on holidays and was absent from the workplace.

With respect to the arguments that the worker's osteoarthritis was not limited to his thumbs, we acknowledge the occupational health physician's comments that: "although you have radiographic evidence of osteoarthritis in other joints, the arthritis in your thumbs is disproportionate to what is seen in other areas." He concluded by stating: "I feel that your occupational exposures both aggravated and enhanced your development of bilateral osteoarthritis of the first carpal metacarpal joint."

Finally, the panel notes that the August 21, 2007 WCB medical advisor's opinion does not refute that the work duties could lead to enhancement of the pre-existing condition. He stated: "… repetitive activity with the hands is just one of the many factors that could aggravate the condition, and also one of the many factors that could lead to further enhancement of the condition necessitating subsequent surgical intervention." While the WCB medical advisor declined to find a direct causal connection, he did acknowledge that a connection was possible.

Based on the foregoing, the panel accepts that the aggravation caused by the worker's job duties worsened his symptoms such that surgical reconstruction was made necessary bilaterally. As such, the panel finds that the worker's pre-existing condition was enhanced and we find that he is entitled to wage loss benefits beyond May 3, 2005. The worker's appeal is allowed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
P. Walker, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 31st day of May, 2013