The Appeal CommissionThe Workers Compensation Act of Manitoba

Preliminary Issue

With respect to the second issue above, the panel notes that two surgeries were performed on January 3, 2008 consisting of a right carpal tunnel release and a right cubital tunnel release. At the hearing, the union representative advised the panel that he would only be advancing an argument for acceptance of the surgery for the right carpal tunnel release.

Background

On January 24, 2007, the worker notified the WCB that she was experiencing pain in both wrists, which she related to her repetitive duties as a grocery cashier, using a keyboard to punch in codes and swiping items over a scanner. She indicated that her job requires a lot of lifting, gripping, twisting and bending of her hands and wrist throughout her shift. Her shifts range from 6 to 8 hours and she was employed with this employer for 6.5 years. She reported that she uses both arms and that it was initially worse in her right hand but now the pain was the same in both hands. The symptoms began about four years before and she was using a brace on both hands. She described sharp pain going up her forearms to her hands and pain, tingling and numbness in her hands and fingers, which had significantly worsened in the previous weeks.

The worker continued to work her regular hours as a cashier of 25 to 28 hours per week with shifts reduced to no more than 5 hours each. She also continued to work 24 hours per week in a second job as a health care aide.

A doctor’s progress report dated February 4, 2007 indicated that the worker sought treatment on January 15, 2007 and January 23, 2007 for discomfort and paresthesia in her hands, wrists and forearms. The report notes objective findings consisted of positive Tinel’s and tenderness in the ulnar nerve with radicular symptoms and that nerve conduction studies were pending. On February 14, 2007, this physician advised the WCB that the worker was suffering from bilateral carpal tunnel syndrome (“CTS”). Physiotherapy treatment was approved by the WCB on February 26, 2007 and the worker was placed on modified duties with the employer.

The worker was referred to a neurologist who examined her on February 28, 2007 and reported that Tinel’s test was positive over both median nerves and negative over the ulnar nerve. The neurologist outlined his impression as follows: “Whereas the historical data suggests initial symptoms in the ulnar distribution bilaterally, the findings at present are more compatible with bilateral carpal tunnel syndrome.” The neurologist requested nerve conduction studies (“NCS”) of the right and left ulnar and median nerves.

The NCS results dated March 9, 2007 indicated that there was evidence of mild right carpal tunnel syndrome and that there was no definite evidence of an ulnar nerve lesion on the right side. No abnormality was reported on the left carpal tunnel.

On April 12, 2007, an orthopaedic specialist examined the worker and noted a positive Tinel sign on the right side and a negative Tinel sign on the left hand. The specialist recommended decompression of the right median nerve. By letter dated April 18, 2007, the WCB advised the surgical clinic that the worker’s claim was accepted for both wrists and requested an expedited appointment.

A WCB medical advisor reviewed the file on April 24, 2007 noting the diagnosis of bilateral CTS and that recent NCS results confirmed right CTS. The advisor recommended that the worker avoid repetitive work involving flexion/extension of her wrists. On April 25, 2007, the WCB approved further physiotherapy treatment for both wrists.

On May 14, 2007, the worker was seen by a plastic surgeon. The surgeon noted that the NCS results confirmed mild right carpal tunnel syndrome but the left carpal tunnel was reported as normal. The surgeon performed the Tinel’s test and noted that it was strongly positive over both carpal tunnels and cubital tunnels and the Phalen’s test was positive over the median nerve after 20 seconds. The surgeon was of the opinion that clinically the worker had bilateral carpal and cubital tunnel syndromes. A right carpal and cubital tunnel release was recommended along with a left carpal and cubital tunnel release at a later date.

On May 23, 2007, a WCB orthopaedic consultant wrote to the plastic surgeon noting that the neurologist diagnosed only bilateral carpal tunnel syndrome and not cubital tunnel syndrome. The consultant advised that the WCB would authorize right carpal tunnel decompression and if after recovering from surgery the worker continued to have symptoms on her left side, the WCB would consider a left carpal tunnel decompression.

On June 11, 2007, the family physician wrote to the WCB in support of the surgeon’s request to release both the carpal and cubital tunnels at the same operation. The family physician noted that the worker’s symptoms of paresthesia and pain radiating down the forearm and into the hand clearly fit the anatomical pattern of the median nerve in both hands and the ulnar nerve in, both hands. He noted that the worker has a positive Phalen’s sign in both hands; positive Tinel’s sign in both hands at the median nerve at the wrist and over the ulnar nerve at the elbow and probable wasting of the thenar muscle bilaterally. The physician also noted the worker’s concern about coming off anti-coagulent medication on multiple occasions if the surgeries were not performed at the same time.

A WCB orthopaedic consultant reviewed the file on June 20, 2007 and concluded that there was no convincing clinical information regarding the diagnosis of cubital tunnel syndrome. He noted that the slight wasting of the thenar muscles bilaterally would be attributable to carpal tunnel compression of the median nerve. He noted that the worker’s concerns regarding discontinuance of anti-coagulant medication would not alter his opinion that if there was cubital tunnel syndrome, it did not arise out of the workplace.

On June 27, 2007, the plastic surgeon advised the WCB that the worker had been scheduled to have surgery to both the right carpal and cubital tunnel areas at the same time, with the cubital tunnel release covered by Manitoba Health.

The WCB arranged for the worker to undergo repeat nerve conduction studies on July 24, 2007. The results showed no indication of right or left carpal tunnel syndrome or of cubital tunnel syndrome.

A WCB call in examination took place on August 9, 2007. The WCB medical advisor noted that the worker had been diagnosed with both bilateral cubital and carpal tunnel syndromes but indicated that the symptoms and clinical findings were not entirely consistent with either of these diagnoses noting the negative nerve conduction studies. The medical advisor concluded that given the nature of the worker’s symptoms and the negative nerve conduction studies, the exact diagnosis causing her complaints was uncertain, the risk/benefit ratio for surgery was not favourable, and surgery would not be authorized for any carpal tunnel or cubital tunnel releases.

In a decision letter dated August 30, 2007, the worker was advised that the WCB was unable to clinically confirm the diagnoses of bilateral carpal or cubital tunnel syndrome and therefore, the WCB was not accepting responsibility for the proposed right carpal tunnel surgery or for wage loss benefits beyond September 8, 2007.

The worker’s surgeon advised the WCB that based on clinical examination, the worker’s condition is consistent with bilateral carpal and cubital tunnel syndrome and he was scheduling the worker for surgery. The WCB responded in a letter dated November 9, 2007 advising that the repeat nerve conduction studies failed to indicate carpal or cubital tunnel syndrome and it was their policy not to authorize nerve entrapment surgery when nerve conduction studies are negative.

On December 20, 2007, the worker’s union representative appealed the WCB’s decision. The submission from the union included a letter dated October 17, 2007 from the worker’s surgeon explaining the reason why normal nerve conduction studies do not alter his clinical diagnosis of bilateral carpal and cubital tunnel syndrome. The surgeon noted the following:

“The diagnosis of carpal and cubital tunnel syndrome is mainly made and relied upon by clinical and historical examination. The nerve conduction studies are not 100% sensitive and are designed with a margin of safety so that they do not overcall patients, that is to diagnose someone with carpal tunnel syndrome that clinically is normal. Approximately 10% of patients with carpal tunnel syndrome will have normal nerve conduction studies and approximately 25% of patients with cubital tunnel syndrome will have normal nerve conduction studies. It is very common to operate on these patients with normal nerve conduction studies and EMG’s but with positive historical and clinical findings, and with excellent outcomes. It is also common that the degree of compression can fluctuate and many patients will have the nerve conduction studies done at a time when their symptoms are mild and therefore the test will not pick up the delayed conduction in the nerve. This is also why many patients may have a positive tinel sign on certain examinations and at other times when the compression is milder the tinel sign will be negative.”

On January 3, 2008 the worker underwent right carpal and right cubital tunnel releases. On January 23, 2008, a WCB medical advisor reviewed the operative report and union submission and concluded that the likelihood of surgery being successful given the inconsistent symptoms, clinical findings and NCS results was poor. On January 24, 2008, primary adjudication informed the worker that there would be no change to the previous decision to end responsibility for her claim. The case was forwarded to Review Office for consideration.

The Review Office asked a WCB senior medical advisor to review the file. The WCB senior medical advisor advised that he was unable to provide a probable diagnosis to account for the worker’s condition citing the absence of electrodiagnostic findings at the elbow or on the left side. The WCB advisor was asked whether the worker’s complaints were likely related to her job duties as a cashier and he responded as follows:

“The position of a grocery cashier would clearly carry with it numerous activities which are consistent with the generation of a repetitive motion disorder. Repetitive postures, the application of force, repetitive movements, all are consistent with a repetitive motion type of disorder. Therefore, there is a possible relationship between the claimant’s work as a cashier, and her clinical condition. Until such time as a probable diagnosis is reached, however, this relationship can only be described as possible and not probable in my opinion.”

On February 28, 2008, Review Office determined that the worker was not entitled to wage loss benefits beyond September 8, 2007 and that responsibility could not be accepted for the worker’s right wrist surgery which took place on January 3, 2008. The Review Office held that on a balance of probabilities a relationship between the worker’s ongoing complaints and her work as a cashier had not been established. On December 8, 2008, the union representative appealed the Review Office’s decision to the Appeal Commission.

Prior to the Appeal Commission hearing, the union representative submitted a medical report from the worker’s surgeon dated June 13, 2008 indicating that following surgery on January 3, 2008, the worker stated she had immediate relief of her symptoms and no longer had the numbness in her digits and thumb and the pain in the wrist and elbow was gone. Left carpal and cubital tunnel surgeries were scheduled for July 8, 2008.

The union representative also submitted a report from the worker’s physiotherapist dated September 10, 2008 noting that following the surgeries on January 3, 2007 and July 8, 2008, the worker reported near resolution of her pre-operative pain and paresthesia. In the physiotherapist’s opinion, the worker’s clinical diagnosis was bilateral cubital and carpal tunnel syndrome.

At the hearing, the employer’s representative took the position that the worker suffered from cubital and carpal tunnel syndrome bilaterally, but that her job duties as a cashier were not the probable cause of this condition. The employer’s representative argued that while the cashier’s duties were repetitive, they did not involve constant repetitive flexion and extension against significant resistance generally associated with CTS. The employer’s representative questioned whether this particular worker was taking long breaks and rest periods in performing her duties as a cashier.

The worker testified that she worked her duties as cashier punching in codes and scanning items for the whole of each shift. If she worked a 4 or 5 hour shift, she took only one 15 minute break and spent the rest of the time at the till engaged in these duties. If she worked a 7 or 8 hour shift she had two 15 minute breaks and one 30 minute break. She testified that she was constantly grabbing items of varying weights including cans and bags of flour weighing 10 pounds with her right hand, transferring them to her left and pushing them over the scanner onto the belt. The worker’s evidence was that the employer required a scanning speed of 30 items per minute and the worker achieved an average of 45 items per minute. The worker also explained that the store where she worked was very busy; that she worked at busy times with little or no waits between customers and that she spent all of her time at the till doing cashier duties.

Analysis

Subsection 4(1) of The Workers Compensation Act provides for compensation “where personal injury by accident arising out of and in the course of employment is caused to a worker”. For the panel to accept the worker’s appeal, we must find that on a balance of probabilities, the worker’s hand and wrist problems were causally related to her job duties as a cashier. The panel finds that the worker’s bilateral hand and wrist problems are so related.

In reaching this decision, the panel is of the opinion that the evidence supports a finding that the worker suffered from bilateral carpal tunnel syndrome and that this condition was caused by her job duties. The panel finds that the cashier duties described by the worker and supported by the physical demands analysis for the position of cashier involved the type of repetitive movement and application of force consistent with this disorder.

In this case, the WCB medical advisors accepted the causal relationship between the worker’s duties and the development of the worker’s hand and wrist symptoms and were unanimously of the opinion that the worker suffered from bilateral carpal tunnel syndrome up until repeat nerve conduction studies were done on July 24, 2007. Prior to that time, the WCB medical consultants were of the opinion that there was clinical information supporting their diagnosis that the worker suffered from bilateral carpal tunnel syndrome. These clinical examination findings included a range of historical and clinical examination findings such as positive tinel and phalen tests as well as the NCS test conducted on March 7, 2007, which only showed evidence of right carpal tunnel syndrome. In his letter of May 23, 2007, the WCB medical advisor, after reviewing all of the previous medical information, concluded that there was insufficient evidence to support surgery for cubital tunnel release; however, he did not question the neurologist’s diagnosis of bilateral carpal tunnel syndrome and authorized surgery on the right carpal tunnel. This consultant also noted that “nerve conduction tests do not necessarily relate to the clinical severity”.

The worker’s surgeon provided a more extensive explanation of the difficulties with relying on NCS results when he noted in his October 17, 2007 letter that 10% of patients with carpal tunnel syndrome will have normal nerve conduction studies; that the degree of compression can fluctuate and many patients will have the nerve conduction studies done at a time when their symptoms are mild and the test will not pick up the delayed conduction in the nerve; and that it is very common for patients with normal NCS results and positive historical and clinical findings to have excellent surgical outcomes. In fact, the worker’s evidence and the medical and physiotherapist’s reports post-surgery indicate a successful outcome with near resolution of symptoms on the right and left hand.

The panel has concluded after considering all of the medical evidence, the file record and the evidence at hearing that the worker suffered from bilateral carpal tunnel syndrome that arose out of and in the course of her employment as a cashier. The panel therefore accepts the worker’s appeal and finds that the worker is entitled to wage loss benefits beyond September 8, 2007 and responsibility should be accepted for the surgical release of her right carpal tunnel performed on January 3, 2008.