Decision #79/10 - Type: Workers Compensation
Preamble
The worker is presently appealing decisions made by Review Office which determined that he had no loss of earning capacity beyond October 10, 2008 and that his left knee complaints were unrelated to his right knee injury of June 23, 2006. A hearing was held on July 8, 2010 to consider these matters.Issue
Whether or not responsibility should be accepted for the worker’s left knee complaints as having a relationship to the right knee injury of June 23, 2006; and
Whether or not the worker is entitled to wage loss benefits beyond October 10, 2008.
Decision
That responsibility should not be accepted for the worker’s left knee complaints as having a relationship to the right knee injury of June 23, 2006; and
That the worker is not entitled to wage loss benefits beyond October 10, 2008.
Decision: Unanimous
Background
The worker filed a claim with the WCB for right leg/knee pain that he related to his job duties as a long haul transport driver on June 23, 2006. The claim for compensation was initially denied by primary adjudication but was accepted by Review Office on October 27, 2006. Review Office determined that the worker’s right knee injury occurred on May 31, 2006 when he was under a truck in a bent position. Medical information showed that the worker’s injury was initially diagnosed as a right hamstring strain but the accepted diagnosis was a lateral meniscus tear. On December 6, 2006, a partial lateral meniscectomy of the right knee was performed. The operative report initially indicated a left knee procedure, but this was subsequently amended to read "right knee".
When speaking with a WCB case manager on March 1, 2007, the worker indicated that his right knee remained unstable. He noted that he was able to walk for about 15 to 20 minutes at a time before he would start having difficulties with his knee. The worker indicated that his left knee gave him trouble as well because he was overcompensating for his right knee. The worker reported that he had left knee surgery in 2000 for non-work related degenerative changes.
On March 27, 2007, a WCB orthopaedic consultant reviewed the claim in order to provide primary adjudication with his opinion concerning the worker’s left knee difficulties. He stated:
There is evidence of significant osteoarthritis of the left knee, longstanding. No clinical evidence of new injury arising out of his compensable injury. Any possible further treatment is not WCB responsibility.
A June 14, 2007 MRI of the worker’s right knee showed a complex tear in the posterior medial meniscus along with patellofemoral chondromalacia.
In a report to the family physician dated July 6, 2007, the treating orthopaedic surgeon suggested that the worker undergo arthroscopic surgery to his right knee because of recent MRI findings that showed the possibility of a recurrent or persistent posterior horn medial meniscal tear. The surgeon also noted that the worker complained of left knee pain which seemed to be because of overcompensating for his right knee. The worker had bilateral genu varus and some medial tenderness. He felt the worker would also benefit from a left knee arthroscopy.
On July 24, 2007, the WCB orthopaedic consultant reviewed the new file information in relation to the worker’s knee conditions. With regard to the right knee, the consultant authorized the proposed arthroscopy. With regard to the left knee, the consultant stated:
There is no irrefutable evidence that the pre-existing osteoarthritis of the left knee has been enhanced by the compensable right knee injury. There is no evidence on file of details of the previous history of surgery to the left knee. Unless it is a WCB responsibility, and my understanding is that it is not, further investigation and treatment of the left knee is not a WCB responsibility.
On July 26, 2007, the WCB orthopaedic consultant wrote the treating orthopaedic surgeon to advise that the WCB was accepting responsibility for all costs associated with the right knee arthroscopy but not for the left knee arthroscopy. The consultant stated:
…information available indicates that there is established degenerative osteoarthritis of this joint, and while it is possible that the abnormal gait arising out of the right knee injury may have caused some increased symptoms from this pre-existing condition, the WCB is unable to accept responsibility for the proposed arthroscopic procedure on the left knee joint.
On September 25, 2007, the worker underwent bilateral knee arthroscopies. Initially, the operative report reversed the two knees and reported chondroplasty and partial medial meniscectomy of the left knee and chondroplasty of the right knee. This was later revised to show chondroplasty/partial medial meniscectomy of the right knee and chondroplasty of the left.
In a report dated October 22, 2007, the orthopaedic surgeon reported that the worker’s right knee showed type 3 chondromalacia of the patellofemoral joint and the worker had a chondroplasty. On the left knee, the worker had some early degenerative changes, type 3 chondromalacia of the patellofemoral joint and type 2 chondromalacia in the medial compartment. The surgeon indicated that the worker: “…doesn’t seem to be getting better although the reason he still has some discomfort is most likely related to his degenerative changes.”
The file was reviewed by the WCB orthopaedic consultant on November 14, 2007. The consultant stated that the operative report relating to the left knee did not alter his previous decision.
On December 10, 2007, a WCB sector services manager wrote the worker to advise that he was unable to make a connection between his right knee injury and any effect it may have had on his left knee condition. On December 24, 2007, the worker appealed the decision to Review Office.
On January 4, 2008, Review Office advised the worker that the medical information on his file was incomplete and therefore it was unable to consider his appeal. The worker was advised that his case would be returned to primary adjudication to obtain additional information concerning his left knee complaints.
On February 15, 2008, a WCB case manager spoke with the worker to obtain details of his prior left knee difficulties which the worker stated had started in 1995/1996 when he hurt his knee when coming off a football field. The WCB also obtained a report from the family physician dated June 9, 2008 which indicated that the worker was first seen for left knee pain on August 5, 1980 following a twist.
The worker had an MRI examination of the right knee on March 3, 2008. The results were outlined as follows:
Changes of chondromalacia is seen within the patellofemoral joint as described. Tear of the posterior horn of the medial meniscus is seen unchanged from the previous examination of 2007.
Right knee surgery was performed on May 23, 2008. The operative report gave a diagnosis of right knee osteoarthritis.
At the request of primary adjudication, a different WCB orthopaedic consultant reviewed the file information on June 19, 2008. In his opinion, there was no medical evidence of aggravation of the left knee because of problems with the right knee. He stated that increased weight bearing on the left knee for a period of time would not by itself be expected to cause deterioration of meniscal lesions.
On June 20, 2008, the WCB advised the worker that his left knee condition was not compensable as his left knee was symptomatic prior to the compensable injury and that the mechanism of increased weight bearing would not result in the diagnosis noted in his left knee. On August 25, 2008, the worker appealed the decision to Review Office.
On July 16, 2008, a WCB orthopaedic consultant reviewed the operative report. In his opinion, the worker’s current symptoms were caused by chondromalacia and patello-femoral arthritis of the right knee and it was not related to the compensable injury. It was indicated that the worker would achieve MMI (maximum medical improvement) 3 months after surgery. He indicated that the worker’s current workplace difficulties were not related to the compensable injury. The arthroscopy did not reveal traumatic changes of the menisci. He said the prognosis was guarded for a return to transport driving.
A senior WCB medical advisor reviewed the file information on September 10, 2008 and September 22, 2008. In his opinion, the worker’s right lateral and medial meniscus tears had resolved and the patellofemoral arthrosis was neither aggravated nor enhanced by the May 31, 2006 workplace accident. He said the December 6, 2006 right knee arthroscopy did not have a significant impact on the current patellofemoral based symptoms.
On October 1, 2008, Review Office determined that responsibility should not be accepted for the worker’s left knee condition as having a relationship to his right knee injury. In making its decision, Review Office relied on the medical opinions provided by the two WCB orthopaedic consultants over the opinion of the treating orthopaedic surgeon made on July 6, 2007.
On October 3, 2008, the worker was advised that wage loss benefits in relation to his right knee would be paid to October 10, 2008 inclusive and final as it was felt that the worker no longer had a loss of earning capacity related to the May 31, 2006 compensable injury.
On October 8, 2008, a worker advisor spoke with the WCB case manager. He referred to the WCB’s pre-existing policy and the definition of enhancement. He questioned whether the surgery was necessary because of the aggravation of the compensable injury.
On October 8, 2008, the WCB senior medical advisor outlined the opinion that the right knee surgery was not necessary on account of an aggravation of a pre-existing condition.
On March 19, 2009, the worker advisor appealed the WCB’s decision to end the worker’s wage loss benefits effective October 10, 2008. The worker advisor outlined the position that the worker had compensable restrictions that prevented him from returning to the trucking industry. He noted that the worker sustained an irregular tear of the free edge of the lateral meniscus which was cut out and shaved on December 6, 2006. He suggested that this was an enhancement in the form of an acceleration. The worker advisor noted that the WCB agreed to the operations performed on September 25, 2007 and May 8, 2008. The pre-existing aspects of the right knee were smoothed in an effort to alleviate the worker’s pain. He suggested that these conditions would be covered as well given the definition of enhancement which applies where a compensable injury permanently and adversely affects a pre-existing condition or makes surgery necessary on a pre-existing condition.
In a decision dated April 16, 2009, Review Office determined there was no entitlement to wage loss benefits beyond October 10, 2008. In making its decision, Review Office placed weight on the opinions expressed by the WCB senior medical advisor. Review Office was of the opinion there was insufficient medical evidence to support that the worker’s pre-existing right knee condition was aggravated by the May 31, 2006 compensable injury. There was no evidence to support that any of the surgeries were required due to an aggravation of the pre-existing condition. It concluded that there was no enhancement of the pre-existing condition and that the medical evidence supported that the current right knee difficulties were solely due to the pre-existing condition of chondromalacia patella and patellofemoral arthrosis.
On June 9, 2009, a different worker advisor asked Review Office to reconsider its prior decisions based on new medical evidence dated May 27, 2009. The worker’s physician outlined the opinion that the right knee condition was compatible with a meniscal tear which was a result of the May 31, 2006 work accident and a repeat arthroscopy was recommended. He noted that the worker also started to experience left knee pain a few months following his 2006 injury and that the pain was located on the anterior and lateral areas of his knee associated with instability. The physician noted that the worker had a medial meniscal tear and he required an MRI to confirm the diagnosis. In all probability, this was secondary to overuse of the left knee as the worker was not able to use his right knee following his injury of May 31, 2006.
In a decision dated July 21, 2009, Review Office determined that the May 27, 2009 report did not alter its previous decision that the worker’s right knee difficulties were solely due to the pre-existing condition of chondromalacia patella and patellofemoral arthrosis. It also found that the May report did not provide rationale to support the opinion that the left knee difficulties were due to the overuse of his left knee as a result of the right knee injury.
On December 22, 2009, the Worker Advisor Office provided Review Office with a November 26, 2009 report from an occupational health physician which supported that the worker’s work injury and subsequent surgeries resulted in significant enhancement that prevented the worker from returning to his pre-accident duties. The report also contained the opinion that the right knee impairment impacted on the condition of the left knee due to the greater reliance on the left leg for weight bearing and standing balance.
On January 18, 2010, a medical consultant to Review Office reviewed the file information and responded to three questions posed by Review Office. The medical consultant provided opinions that:
· there was insufficient medical evidence to support that the worker’s current right knee difficulties were related to the compensable injury of June 2006;
· the surgical procedures did not enhance the worker’s pre-existing right knee chondromalacia of the patellofemoral joint; and
· there was insufficient information to establish that the worker had greater reliance on his left knee for weight bearing and standing balance in the clinical examinations on file.
On March 10, 2010, Review Office confirmed that there was no entitlement to wage loss benefits beyond October 10, 2008 and that no responsibility should be accepted for the worker’s left knee condition. Review Office accepted the opinions of the medical consultant to Review Office in his January 18, 2010 memorandum to conclude that there was insufficient medical evidence to support a causal relationship between the worker’s current right knee difficulties and the compensable injury and subsequent surgeries. It found insufficient medical evidence to support that the worker’s left knee condition was related to the compensable injury. On March 17, 2010, the Worker Advisor Office appealed Review Office’s decisions to the Appeal Commission and a hearing was arranged.
Reasons
The issue under consideration by the appeal panel was framed using the accident date of June 23, 2006 but ultimately, it was determined by the Review Office on October 27, 2006 that the worker's injury occurred on May 31, 2006 when he was under a truck in a bent position.
Applicable Legislation:
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(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 44.10.80.40, Further Injuries Subsequent to a Compensable Injury (the “Further Injuries Policy”) applies to circumstances where a worker suffers a separate injury which is not a recurrence of the original compensable injury, but where there may be a causal relationship between the further injury and the original compensable injury. The Further Injuries Policy provides:
A further injury occurring subsequent to a compensable injury is compensable:
(i) where the cause of the further injury is predominantly attributable to the compensable injury; or
(ii) where the further injury arises out of a situation over which the WCB exercises direct specific control; or
(iii) where the further injury arises out of the delivery of treatment for the original compensable injury.
A further injury which occurs as a result of actions (for example, medical treatment) known by the worker not to be acceptable to the WCB is not compensable.
Worker’s Position:
The worker appeared at the hearing with the assistance of a worker advisor. It was submitted that there was, on a balance of probabilities, an ongoing relationship between the worker's right knee difficulties and his May 31, 2006 workplace injury. It was also submitted that the worker's left knee condition developed as a consequence of his compensable right knee injury.
With respect to the left knee, it was noted that the worker waited five months after his workplace injury before his first WCB approved right knee arthroscopy. File documentation confirmed that he made complaints of left knee pain prior to the surgery. He had difficulty recovering from the surgery, with ongoing pain, feelings of instability, episodes of his right knee giving way, as well as difficulty walking and climbing stairs. He underwent another two WCB supported arthroscopies in September 2007 and May 2008. During this entire time, the worker had ongoing difficulties with his right knee, which necessitated a greater reliance on the left knee. It was submitted that the increased demands placed on the worker's left knee caused an acceleration of the degenerative processes in the left knee joint. The left knee condition was compensable because the compensable right knee injury significantly contributed to its development/enhancement of a pre-existing degenerative knee condition.
With respect to the right knee, it was noted that despite evidence of pre-existing degenerative changes in the right knee, the worker was able to function in his occupation and daily living without difficulty until the compensable injury. The worker's evidence was that his knee has never been the same since the initial accident. It was submitted that the workplace accident caused structural damage to his knee joint, which caused pre-existing degenerative processes to progress at an accelerated pace. Furthermore, surgical treatments and attempts to mitigate the structural damage, only served to reduce the weakened foundation of the worker's right knee. The pre-existing degenerative processes had been enhanced by way of a compromised structural integrity and resultant accelerated deterioration. It was also submitted that given the convoluted medical evidence, the benefit of the doubt should be given to the worker and ongoing responsibility for his right knee condition should be accepted by the WCB.
Analysis:
There are two issues before the panel. Each will be addressed separately.
1. Whether or not responsibility should be accepted for the worker’s left knee complaints as having a relationship to the right knee injury of May 31, 2006.
The worker claims that he has suffered a secondary injury as a result of his compensable right knee injury. He contends that the pre-existing osteoarthritis in his left knee was worsened as a result of limping and altered gait. The worker’s evidence at the hearing was that by approximately July 2006, he was starting to experience pain in his left knee. The worker admitted that he had an arthroscopy to the left knee in 2000. At that time, he had what was termed “significant arthrosis” and the worker stated that the orthopedic surgeon “cleaned it up.” Since 2000, the worker said that he has had no problems with his left knee, aside from some minor aches and pains. After the compensable workplace injury, the worker started to limp and place more strain on the left side. He described his left knee problems as a feeling of grinding, with aching on the medial side of his knee and "ratcheting" on the lateral side. In July, 2008 he was referred to an orthopedic surgeon specializing in joint replacements and he was promptly listed for a total left knee replacement. This procedure was performed in January 2010, and the worker was still recovering from the surgery at the time of the hearing.
In order for the worker’s appeal on this issue to succeed, the panel must find that his left knee condition qualifies as a “further injury” under one of the three tests set out in the Further Injuries Policy. The test applicable to the worker’s left knee injury would be the one contained in paragraph (i), that is, whether or not the cause of the further injury is predominantly attributable to the compensable injury.
The administrative guidelines to the Further Injuries Policy provide as follows:
A subsequent accident or injury may be compensable if a relationship between the original compensable injury and the subsequent injury is established where:
1. The original injury causes or significantly contributes to the subsequent injury. For example, the subsequent injury results from a residual weakness in the area of the original injury (e.g. unstable knee) or from the use of a prosthetic devise or other appliance. The test for whether the subsequent accident is compensable may include whether, on balance of probabilities, the unstable knee caused or significantly contributed to the subsequent accident or whether the prosthetic device/appliance malfunctioned or there was extraordinary risk associated with the use of the device/appliance.
After reviewing the evidence as a whole, the panel is not satisfied, on a balance of probabilities, that the worker’s compensable right knee injury significantly contributed to the enhancement of his left knee osteoarthritis and we do not feel that the need for his left total knee replacement was predominantly attributable to the compensable injury. In coming to our decision, the panel relied on the following:
- In January 2010, the worker had total knee replacement surgery of his left knee. He had been referred for this surgery two years earlier by his second treating orthopedic surgeon. The panel does not accept that two years of limping/altered gait alone would cause the worker’s left knee to deteriorate to the point where knee replacement surgery was required. The panel is of the opinion that the deterioration was a long term process which had been continuing since long before the workplace accident. When the worker had his left knee arthroscopy in 2000, there was already “significant arthrosis” which in all likelihood continued to worsen;
- The worker’s evidence at the hearing was that since he went off work in October, 2006, he had been careful to stay off his feet and he estimated that on any given day, he would only spend about 1 hour in total on his feet, either standing or walking. In the panel’s opinion, this represents a relatively small amount of time when the left knee would be subjected to additional loading;
- Although the worker continued to work until October, 2006, he indicated that he did not perform much of the heavy physical work required by his job and he would get others to assist him. With respect to the driving duties, there would not be much strain on the left leg as the right leg was the one which he used to operate the accelerator and brake pedals.
- The panel agrees with the opinions of the WCB medical advisors that there is little in the way of evidence of additional weight bearing or balance abnormality of significance on the left side which would support a relationship between accelerated degeneration in the left knee and the compensable right knee injury.
For the foregoing reasons, we find that responsibility should not be accepted for the worker’s left knee complaints as having a relationship to the right knee injury of May 31, 2006. The worker’s appeal on this issue is dismissed.
- Whether or not the worker is entitled to wage loss benefits beyond October 10, 2008.
In order for the worker’s appeal on this issue to be successful, the panel must find that the worker’s current right knee complaints are related to the May 31, 2006 compensable injury. On a balance of probabilities, we are not able to make that finding.
The worker’s case was a complex one, involving multiple surgeries, inconsistent medical reports and varying opinions. It was submitted by the worker advisor that given the convoluted medical evidence, the benefit of the doubt should be given to the worker and ongoing responsibility for his right knee condition should be accepted by the WCB.
While the panel is sympathetic to all the frustration the worker has experienced in relation to sorting out the medical reports, we are of the opinion that there is enough information contained in the third arthroscopy report of May 23, 2008 to satisfy us on a balance of probabilities that the worker’s continuing right knee difficulties are not attributable to an acute injury sustained while at work on May 31, 2006. We are also satisfied that the treatment related to the May 31, 2006 injury, and in particular, the three arthroscopic surgeries, did not enhance or accelerate the pre-existing arthrosis in the worker’s right knee.
With respect to the existence of an acute injury, the panel notes that the third arthroscopy of May 23, 2008 identified that the meniscus was intact, despite the MRI findings. The occupational health physician and the worker's physician both suggested that the worker showed signs of a medial meniscal tear. The review by the medical consultant to Review Office rejected this diagnosis as being unsupported by the medical evidence. He relied primarily on the first and third arthroscopies of the right knee as reliable evidence that the meniscus was intact and that there was no medial meniscal tear. The panel agrees that the arthroscopic findings (and in particular, the findings on the third arthroscopy) are more reliable than what is suggested by the MRI images. After considering the evidence as a whole, the panel finds that the arthroscopic findings of an intact meniscus are the most reliable evidence upon which to conclude that there is no ongoing meniscal tear injury in the worker’s right knee which was caused by the work related accident. It therefore follows that the worker’s ongoing difficulties in his right knee are not due to an acute injury sustained at work.
With respect to whether the WCB approved surgeries enhanced a pre-existing condition in the worker’s right knee, the panel agrees with the assessments of the WCB medical advisors dated September 22, 2008 and January 18, 2010. Given that the degenerative changes in the worker’s right knee are primarily patellofemoral in nature, it is not evident that the meniscal arthroscopic interventions have made the patellofemoral pain worse. The panel also notes the comments in the January 18, 2010 assessment which state that on the third arthroscopy, the chondromalacia of the patellofemoral joint was still Grade iii, the same magnitude as was observed at the first arthroscopy. These clinical findings would indicate that there was not a progressive worsening of the pre-existing patellofemoral condition.
The November 26, 2009 report from the occupational health physician opines that the repeated partial medial meniscectomies had damaging effects on the knee leading to less stability of the knee joint with long term sequelae of enhancing degenerative changes. Again, the arthroscopic findings on the third arthroscopy do not support this position. The lateral compartment, cruciate ligaments, and cartilaginous surfaces of the medial compartment were all described as normal. The meniscus was described as being intact. The noted degenerative changes were limited to the patella and the trochlea. Therefore, while the panel accepts that arthroscopic interventions may in some circumstances cause enhancement of pre-existing degenerative changes, we find on a balance of probabilities that the evidence does not support that there was an enhancement in this case.
For the foregoing reasons, the panel finds that the worker’s current right knee complaints are not related to the May 31, 2006 compensable injury. Accordingly, the worker is not entitled to wage loss benefits beyond October 10, 2008. The worker’s appeal is dismissed.
Panel Members
L. Choy, Presiding OfficerC. Devlin, Commissioner
P. Walker, Commissioner
Recording Secretary, B. Kosc
L. Choy - Presiding Officer
Signed at Winnipeg this 23rd day of August, 2010