Decision #45/11 - Type: Workers Compensation

Preamble

The worker filed a claim with the Workers Compensation Board ("WCB") for a low back injury that occurred at work on March 12, 2009. The claim for compensation was accepted and benefits were paid to the worker up to March 16, 2010 when it was determined by primary adjudication that he had recovered from the effects of his compensable injury and that his current symptoms were related to pre-existing degenerative disc disease. The decision was upheld by Review Office on May 6, 2010. The worker disagreed and an appeal was filed with the Appeal Commission. A hearing was held on February 15, 2011 to consider the matter.

Issue

Whether or not the worker is entitled to wage loss benefits after March 16, 2010.

Decision

That the worker is not entitled to wage loss benefits after March 16, 2010.

Decision: Unanimous

Background

The worker reported to the WCB that he injured his low back on March 12, 2009. He was salting and sanding a walkway when he slipped on ice and fell to the ground. He was unable to complete his shift that day and left work because of the pain.

The employer's accident report indicated that the worker was salting and sanding when he slipped and fell backwards on March 12, 2009.

Medical reports showed that the worker attended a hospital facility on March 12, 2009 for a back injury. The report noted that the worker had a pre-existing back injury. The worker had mild tenderness in the lumbar spine and tenderness to the right lumbar area. The diagnosis was lower back pain.

The claim for compensation was accepted based on the diagnosis of a back strain/contusion and benefits were paid to the worker.

With regard to the worker's pre-existing back history, an MRI report of the lumbar spine dated April 7, 2008 revealed the following findings:

At the L2-3 level there is minor posterior disc bulging without evidence of significant central or foraminal stenosis.

At the L3-4 level there is a mild posterior disc bulge. No significant central or foraminal stenosis results.

At the L4-5 level there is mild disc bulging without significant central or foraminal stenosis. Degenerative changes are also demonstrated at the left facet with synovial cysts noted.

At the L5-S1 level there is a posterior annular tear with mild posterior disc bulging. No evidence of nerve root contact or compression is identified. No significant central or foraminal stenosis results.

In a report dated June 9, 2008, a neurosurgeon reported that he saw the worker on May 15, 2008. He noted that the MRI study confirmed degenerative disc disease at L3-L4, L4-L5 and L5-S1. There was a small annulus tear in L5-S1. He said he did not see severe spinal stenosis or signs of neural compression that would prompt one to consider surgical intervention for the worker's symptoms. He suggested that the worker see a physiatrist for further treatment rather than have spine surgery.

With regard to medical treatment beyond March 12, 2009, a doctor's first report dated April 16, 2009 reported that the worker had a tender coccyx, lumbar region muscle spasm, and pain down both legs with the right more affected than the left. Straight leg raising was reduced bilaterally.

A physiotherapist's initial assessment of the worker dated April 15, 2009 diagnosed the worker with an L4-5 disc prolapse. On May 6, 2009, the physiotherapist reported that the worker's progress was slow. He had constant pain to his low back which shot up to the neck. The worker also complained of headaches.

On May 8, 2009, the treating physician referred the worker to a pain clinic specialist. The physician reported that the worker had chronic severe low back pain with radiculopathy into both legs. He noted an injury at the work place.

On May 22, 2009, the treating physician noted that the worker had headaches and low back pain with radiculopathy of the right leg unchanged. He also had weakness in the left leg.

A doctor's progress report dated July 20, 2009 indicated that minimal activity involving the arms was creating headaches and radiculopathy in the right arm C4-C5 distribution. Back symptoms and leg symptoms were unchanged. Due to the long waiting periods to see a specialist, an assessment by the WCB on further management was suggested.

On August 9, 2009, the worker underwent an MRI of the lumbar spine and the results showed the following findings:

The L1-2 and L2-3 levels appear normal.

The L3-4 level demonstrates moderate facet overgrowth and ligamentum flavum hypertrophy. There is no significant disc protrusion. The central canal and foramina are well maintained.

The L4-5 level demonstrates mild-to-moderate facet overgrowth and ligamentum flavum hypertrophy. There is a shall central disc protrusion. This does not appear to compromise the central canal or foramina.

The L5-S1 level is well maintained. There is no significant disc protrusion. The central canal and foramina are well maintained.

The worker was seen by a WCB medical advisor on August 17, 2009. The medical advisor reported that his clinical examination demonstrated a mild decrease in the range of motion of the lumbosacral spine and a negative neurological examination. He stated that a recent MRI demonstrated a shallow disc protrusion at L4-5 level, and that a previous MRI scan of the lumbosacral spine performed in 2008 prior to the compensable injury demonstrated mild multi-level degenerative disc bulges. He said the current clinical findings were most consistent with non-radicular nonspecific low back pain, with a shallow disc protrusion at L4-5 level on recent MRI scan. The worker had a history of pre-existing, symptomatic, multilevel degenerative lumbosacral disc disease. The consultant indicated that the worker would be referred to a spine physician for a possible corticosteroid injection and a more progressive physiotherapy treatment program when his symptoms have settled down, followed by a return to work program to his regular duties. Current workplace restrictions were outlined as follows: to avoid lifting more than 25 lbs and avoid repetitive or sustained bending at the waist, for a three month period.

On September 28, 2009, the worker commenced a graduated return to work program.

On October 6, 2009, the treating physician advised the WCB that the worker returned to work for three days and developed severe migraine headaches. The worker's back pain increased to a point of having difficulty getting up from the sitting position. The examination of the spine was unchanged since the last visit.

In a consultation report dated November 2, 2009, a physical medicine and rehabilitation specialist (physiatrist) stated in summary: "…this patient has a chronic history of low back pain, dating back approximately 10 years, with a recent change following a slip and fall at work. Currently he has a non-specific clinical presentation with some symptoms that may be consistent with radicular pain affecting either the right L5 or S1 spinal nerves. He has a normal neurological examination. In general, this clinical presentation is not well supported by the two imaging studies. It does not appear that the two studies are substantially different morphologically. It is probable that his headache and worsening low back pain is related to his chronic use of …medications."

In a follow-up report dated January 12, 2010, the treating physiatrist's impression of the worker's status was outlined as follows:

  • Acute on chronic low back pain, with possible radicular component affecting the L5 or S1 spinal nerves;
  • Chronic pain disorder; and
  • Possible depression

In a consultation report dated February 19, 2010, the pain clinic specialist advised the treating physician that the worker's pain was multifactorial in origin, and it was likely contributed to by facet joint arthropathy at the L4-5 and L5-S1 levels. With regard to the worker's neck complaints, there was no evidence of muscular or bony abnormalities on the examination. He did not, however, have any previous documentation of imaging at this level.

On March 8, 2010, a WCB medical advisor reviewed the file and outlined the following opinions:

  • the current diagnosis appears to be non-radicular low back pain in the setting of chronic low back pain secondary to degenerative disc disease and lumbar facet arthropathy. Dural tension tests have been negative and neurological findings have been inconsistent;

  • the worker's current symptoms were consistent with degenerative disc disease of the lumbar spine. There was a temporary exacerbation of his symptoms with the March 12, 2009 workplace incident.

  • the worker's current symptoms were not likely related solely to the injury of March 12, 2009 but more likely related to pre-existing degenerative changes in the lumbosacral spine.

In a March 9, 2010 decision, the worker was advised that the WCB could no longer accept responsibility for his claim beyond March 16, 2010 as it was felt that his current symptoms were likely related to the pre-existing degenerative changes in his lower back. On April 22, 2010, the worker appealed the decision to Review Office.

In a consultation report dated June 22, 2010, an orthopaedic surgeon reported "…the clinical evaluation does not match the perceived pain score as well as the Oswestry score of 70/100. He has chronic lumbar disc disease effecting every level of his spine. However, if a discogram at L5-S1 and L4-5 could prove the pain generator I will certainly consider him for a single level arthroplasty or possibly a double level if need be…"

On May 6, 2010, Review Office determined that the worker was not entitled to wage loss benefits after March 16, 2010. In making its decision, Review Office referred to various medical opinions on file from specialists and WCB medical consultants to support its position that the worker's current difficulties were no longer related to the back strain/contusion that he suffered at work on March 12, 2009. On October 7, 2010, the worker appealed Review Office's decision to the Appeal Commission and a hearing was arranged.

Reasons

Applicable legislation:

The issue before the panel is whether or not the worker is entitled to wage loss benefits after March 16, 2010. Under subsection 4(1) of The Workers Compensation Act (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(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 resulting from the accident ends.

WCB Policy 44.10.20.10 Pre-Existing Conditions (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.

Worker’s position:

The worker appeared at the hearing and was assisted by legal counsel. It was submitted that for an injury to be an "aggravation" rather than an "enhancement," the effect must have been temporary, such that the condition would return to its pre-accident state. In this present case, the worker's condition had not returned to its pre-accident state. His symptoms were now substantially worse than anything he experienced prior to March 2009. There was medical information on file which was supportive of the worker's position, and none of the medical information suggested that the workplace incident was not a material contributing factor to the worker's current state of disability. It was submitted that on a balance of probabilities, it was much more likely than not that the worker's current condition was due to the workplace incident and that the appeal ought to be allowed.

Analysis:

In order for the worker’s appeal to be successful, the panel must find that the ongoing difficulties the worker has experienced with his back after March 16, 2010 are related to the injuries he sustained in the workplace accident of March 12, 2009. While it is evident that the worker has not been able to return to his pre-accident status, the question to be determined is whether his difficulties are the result of the workplace accident, or whether they are attributable to degenerative changes in the worker’s back. On a balance of probabilities, we find that the work related low back injury had resolved by March 16, 2010 and that the worker’s current difficulties are attributable to degenerative changes in his lumbar spine.

At the hearing, it was emphasized by legal counsel that prior to the workplace injury, the worker had been in the workforce for many years and was able to manage his pre-existing condition. It was only after the work injury that he became unable to continue working. When asked about his condition prior to the accident, the worker's evidence was that he had "some headaches" and "some pain" but that it was manageable. He indicated that he had been under the care of his family doctor for 3 to 4 years prior to the accident, and in early 2008, his family doctor referred him to a neurosurgeon due to concerns about worsening low back pain. At about that time, he also started taking opiods for pain relief. The worker estimated that prior to the accident, he would take 2 to 3 tablets per day. The worker was susceptible to increased pain if he overexerted himself, and he regularly missed approximately 3 to 4 days from work per month. In 2007, he was off work for a full month due to an exacerbation of his low back condition.

Since the accident, the worker had been completely unable to work. His use of painkillers had increased to 5 to 6 tablets per day. The worker was currently under the care of an orthopedic surgeon. Diagnostic discograms had been performed in late 2010 but the worker was told that the results did not reveal any condition amenable to surgery. A further MRI had been ordered and the worker was scheduled for this in June 2011.

The difficulty the panel had with this case is that aside from a temporal relationship between increased complaints of pain and the workplace fall, there was little in the way of medical evidence to establish an ongoing injury from the workplace accident. A temporal relationship alone in this case is not sufficient to satisfy the panel that the worker's current complaints are related to the compensable injury.

On the other hand, there was extensive evidence of a significant pre-existing degenerative back condition which appeared to be getting progressively worse. At the time of the accident, the worker was already taking strong painkillers on a daily basis and was regularly missing time from work. None of the doctors who examined the worker found convincing evidence of a neurological or disc injury resulting from the accident. The MRI imaging from before and after the accident show little change in the extent to which the discs were protruding and none show any nerve root impingement. Meanwhile, the post-accident MRI results do show new findings of moderate facet overgrowth and ligamentum flavum hypertrophy, thus suggesting the worker's degenerative condition had advanced in the intervening sixteen months.

At the hearing, the panel was urged to place greater weight on the opinion of the family physician, given his regular contact with the worker and knowledge of the worker's condition both pre- and post- accident. While the panel agrees that the family physician identifies the date of accident as being the commencement of a change in the worker's condition, we do not read his brief reports as providing the opinion that the worker's ongoing back complaints after March 16, 2010 are related to the workplace injury. In fact, in a number of third party insurance forms completed by the physician, the primary diagnosis is identified as L4-5, L5-S1 disc degeneration.

Overall, the panel feels the worker had a slowly worsening low back condition, consistent with the natural progression of degenerative disease. While the workplace accident may have temporarily aggravated the worker's symptoms, we do not feel that his ongoing difficulties one year later are attributable to the original injury. In our opinion, paragraph 1(b) of the Policy applies, in that the injury from the workplace accident is no longer contributing to a material degree to the worker's loss of earning capacity and the medical evidence, and in particular, the MRI imaging, does not support that the pre-existing degenerative condition has been enhanced.

The panel therefore finds that the difficulties the worker experienced with his back after March 16, 2010 are not related to the injuries he sustained in his workplace accident. As a result, the worker is not entitled to wage loss benefits beyond March 16, 2010. The worker's appeal is dismissed.

Panel Members

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

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 13th day of April, 2011

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