Decision #71/11 - Type: Workers Compensation

Preamble

A hearing was held on March 10, 2011 to consider the matter.

Issue

Whether or not the worker is entitled to benefits beyond August 11, 2009.

Decision

That the worker is not entitled to benefits beyond August 11, 2009.

Decision: Unanimous

Background

In an Employer's Report of Injury dated February 19, 2009, the employer indicated that the worker slipped and fell backwards on February 10, 2009 and injured his right knee. The worker booked off on February 13, 2009 for a doctor's appointment for two hours. A sprain/strain of the knee was reported.

A doctor's first report confirmed that the worker was seen for treatment on February 13, 2009 and was reported to have subjective complaints of pain in the right knee which increased with activity. Objective findings were no swelling, no erythema, no heat, ligaments good, no pain with meniscal testing.

In a follow-up report dated February 27, 2009, the worker reported subjective complaints of increased pain with sudden starts and stops. Slight pain with rotation and with stairs. No swelling was noted and no effect on work with previous restrictions. Objective findings were good range of motion, minimal tenderness of the lateral/medial tibial condyles and no ligamentous laxity.

In follow-up report dated March 26, 2009, the worker's subjective complaints included locking of the knee with pivoting, pain on stairs and some swelling with exertion. Objective findings were no erythema, no edema, good range of motion, ligaments good, and slightly tender medial and lateral joint.

On May 27, 2009, the worker underwent an MRI of the right knee which showed a tear proximal to the posterior cruciate ligament ("PCL") and a horizontal tear of the medial meniscus.

On July 27, 2009, the case was referred to a WCB medical advisor by primary adjudication. The case manager noted that the worker had a history of knee problems dating back to 2003 with locking, tender medial joint line and ACL laxity. In response to questions posed by the case manager, the medical advisor provided the following opinion:

The noted medial meniscus finding on MRI is common in asymptomatic individuals and is difficult to relate to the February 10, 2009 injury given the clinical findings of the February 13, 2009 and February 27, 2009 findings. At this time, the medial meniscus horizontal cleavage tear which may or may not be symptomatic cannot be related on a clinical and temporal basis to the compensable injury. PCL tears are typically as a result of significant direct impact on a bent knee forcing significant posterior translation of the tibia in relation to the femur. The documented February 10, 2009 injury does not involve these mechanisms. Further there was no documented effusion (which would be expected 3 days post PCL rupture) or ligament laxity in the February 13, 2009 report. As such, at this time, the writer is unable to establish a causal relationship to the compensable injury.

In a decision dated August 11, 2009, primary adjudication advised the worker that as of August 12, 2009, no further medical or time loss would be accepted as related to his compensable injury.

On October 31, 2009, the worker's union representative asked Review Office to reconsider the decision and to make determinations on the following issues:

  1. Whether the worker's ongoing right knee difficulties were the result of the February 10, 2009 workplace injury;
  2. Whether an enhancement or aggravation of a pre-existing condition had occurred as a result of the compensable injury; and
  3. Whether the worker's employment caused changes within the knee joint to be accelerated.

Attached with the union's submission were medical reports from the treating physician and surgeon, information from a co-worker who witnessed the worker's accident, information from a supervisor who confirmed that the worker limped and complained of knee difficulties from the date of accident to the present and medical literature.

By report dated October 19, 2009, the treating physician indicated:

  • The first visit with the worker was three days after the twisted right knee injury.
  • He did not feel that lack of effusion three days post injury was sufficient evidence to exclude acute injury.
  • There was a definite injury with subsequent findings on MRI consistent with an injury, and not degenerative changes
  • The most significant injury involved the medial meniscus as the surgeon was planning to repair the meniscus not the ligament and that would be the basis for any time taken from work.

In correspondence dated November 4, 2009, the treating surgeon wrote:

"Unfortunately, since I was not involved in his care until 5 mos. after the injury and therefore did not examine him until then, I cannot refute or support the temporal relationship of the injury. It appears that [treating physician] did not document an effusion or ligamentous laxity. However, I do feel that the mechanism of injury described would be sufficient to cause either of the identified injuries. An effusion would be expected after PCL rupture, but not necessarily with a meniscal tear.

No degenerative changes are identified on the MRI report I have. However, a horizontal tear usually occurs in a degenerative meniscus. Therefore, if the meniscal tear occurred on February 10, 2009 it would be considered an enhancement of a pre-existing condition. This does not relate to the PCL tear."

As Review Office determined that the union representative's submission contained new information that was not previously considered by primary adjudication, the file was returned to consider the new information.

On December 16, 2009, the WCB case manager contacted the witness who saw the worker's accident. The co-worker stated the following:

  • the worker was walking outside and the ground was slippery/iced;
  • the worker was carrying objects. He could not recall what but some objects were under the worker's arms and others were being carried in front of his body;
  • the worker lost his footing and fell backwards. The worker fell "kind of twisted". The worker fell back with his leg behind him landing on his back. He could not recall which leg it was but he believed it was the right leg;
  • the worker did not fall forward or directly onto a bent knee. The one leg was "kind of bent behind him" as he fell and the worker fell on his back, and the objects fell on him and some fell on the ground;
  • the worker was slow to get up. He helped him gather his things and then the worker continued to work. He could not recall if the worker complained for the remainder of the day.

In a decision dated December 17, 2009, primary adjudication indicated that there would be no change to the decision of August 11, 2009. With regard to the PCL tear, the case manager referred to the information he obtained from the witness who saw the worker's accident. He noted that a PCL tear was associated with direct force on a bent knee or direct force on the front of the shin forcing the knee backward or causing hyperextension. It was felt that the mechanism of injury described by the witness was not in keeping with a PCL tear.

The case manager noted that the worker's union representative provided argument that the twisting motion of the accident could have caused the horizontal medial meniscus tear and associated parameniscal cyst. The case manager noted that the medical literature provided by the union mentioned that radial tears are associated with traumatic events and horizontal tears are more in keeping with degenerative changes within the knee joint. He noted that upon his research of parameniscal cysts, there was a medical consensus that points to the conclusion that: cysts in association with horizontal tears are thought to be degenerative in nature and that a cyst void of an associated tear is thought to be traumatic in nature. The attending physician provided the opinion that he could see no degenerative changes within the MRI; however, the case manager said this was not in keeping with current medical evidence or standard orthopaedic opinion. As there was no radial tear or cyst void of associated tear, the case manager could not find that the horizontal medial meniscus tear was related to the February 10, 2009 compensable accident.

The case manager confirmed that the worker had pre-existing degenerative joint disease ("DJD") and that imaging had not shown any additional injury other than the DJD. The case manager indicated that he could not come to the conclusion that the worker's knee, on a balance of probabilities, was enhanced due his compensable injury.

Finally, the case manager stated that he could not address the issue of whether the worker's employment in general caused or enhanced his DJD, as this was outside the scope of this claim and that a new claim would have to be filed to consider this issue.

In a submission to Review Office dated December 30, 2009, the union representative stated, "…all information on common causes of PCL and meniscal tears (both in keeping with the accident description), and most notably, the drastic change in the worker's function (sic) ability immediately following the workplace injury, it is our position that the workplace injury of February 10, 2009 caused the PCL tear, as well as an enhancement to any pre-existing condition (menisci) within the joint. As such any/all time loss, benefits and treatments associated with and since the workplace injury of February 10, 2009 should be accepted for responsibility by the WCB."

On March 15, 2010, the employer's representative submitted to Review Office that it opposed any amendment to the case manager's decisions dated August 11, 2009 and December 17, 2009. The representative submitted that there was no credible evidence that would establish a cause and effect relationship between the May 27 MRI pathology and the incident of February 10, 2009. He relied on the clinical findings of the attending physician which revealed no effusion, no ligamentous laxity and specific meniscal testing designed to delineate such a lesion. With respect to the issue of enhancement or aggravation of a pre-existing condition, the representative indicated he was unaware of any diagnostic confirmation that these two conditions existed prior to the February 10, 2009 accident.

On March 31, 2010, the union representative provided rebuttal to the employer's submission of March 15, 2010.

On April 14, 2010, a medical opinion was obtained from a WCB orthopaedic consultant which stated:

  • On balance of probabilities, the PCL tear is not related to the compensable injury; and
  • On balance of probabilities, enhancement of the tear of the medial meniscus occurred in relation to the compensable injury and resulted in ongoing symptoms including the sensation of locking, and leading to an orthopaedic recommendation of surgery on the meniscus.

In a decision dated May 20, 2010, Review Office determined that the worker was not entitled to benefits beyond August 11, 2009. Review Office indicated that it accepted the description provided in the Employer's Incident and Injury form dated February 11, 2009 that the worker "slipped & fell backwards" causing an injury to the right knee. When considering this mechanism of injury, Review Office accepted the opinion provided by the WCB orthopaedic consultant on April 14, 2010 which stated in part:

The physiotherapist report dated 13 May 2009 refers to right hamstring problems. A stretching injury of the right hamstrings would be expected with hip flexion and knee extension - not dropping down and striking the bent right knee on the ground.

Review Office indicated that it did not accept the description on file that the worker "…fell backwards with his right knee slamming down onto concrete." It did accept that the worker twisted his right knee as this was the description provided to the physician and orthopaedic specialist.

Review Office referred to evidence on file to support its position that the PCL tear of the right knee and the complete horizontal tear involving the posterior horn and body of the medial meniscus, were not related to the workplace accident of February 10, 2009.

Review Office was unable to find that the worker's medial meniscus injury, which was considered to be a pre-existing condition, was aggravated or enhanced as a result of the accident.

Review Office accepted that the compensable injury was a sprain involving the worker's right knee and also involved weakness pertaining to the worker's hamstring. Review Office felt that the PCL injury was caused sometime after the February 10, 2009 accident as the symptoms expected with this type of injury were not present immediately following the accident. It was felt that any possible further medial meniscal tearing would have been associated with the time the PCL occurred. It therefore did not find that any aggravation or enhancement of the worker's medial meniscus occurred on February 10, 2009.

Review Office noted that the description of "locking" appeared March 26, 2009, some six weeks post accident. As this symptom was commonly found with meniscus injuries in general, Review Office opined that on a balance of probabilities, the worker did not have an injury to his medial meniscus on February 10, 2009.

It did not find evidence to support that the worker suffered any long lasting effects from his hamstring injury and therefore considered it to be resolved. It concluded that the compensable injury of a right knee strain would have resolved by August 11, 2009. It did not accept the findings of a PCL or medial meniscus tear as being caused by or aggravated/enhanced as a result of the workplace accident/compensable injury. On June 8, 2010, the worker's union representative appealed Review Office's decision to the Appeal Commission and a hearing was arranged.

Following the hearing, the appeal panel requested additional information from the worker's family physician. This information was later received and was forwarded to the interested parties for comment. On April 26, 2011, the panel met further to discuss the case and render its final decision.

Reasons

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(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.

The worker’s position:

The worker was accompanied by a union representative at the hearing. It was the worker's position that given the violent mechanics of his twist and fall injury, the medical support from the hands-on treating physicians, and most obviously, the immediate and unresolved changes in the worker's functional ability until post surgery, the WCB should accept full responsibility for all time loss, benefits and services from the time of injury until post surgery resolution of the symptoms. It was submitted that both the PCL and meniscal injuries were either initiated or enhanced on February 10, 2009, changing the worker's life significantly until corrective surgery was performed. It was noted that after the surgery, the worker had only a brief two week healing period of time loss from work, following which he has enjoyed a full recovery with little difficulty, despite the remaining PCL tear within his knee joint.

The employer’s position:

An employer advocate represented the employer at the hearing. It was submitted on behalf of the employer that the evidence did not support the worker's position. The employer noted that as a result of the slip, the worker only missed a total of two hours from work and thereafter was able to continue with his regular duties. Three days later, he was seen by his attending physician who provided a diagnosis of sprained right knee, which was arrived at after the physician performed meniscal testing. Noticeably absent was any effusion, erythema or ligamentous laxity. Follow up examinations also revealed minimal tenderness, no ligamentous laxity, no swelling and good range of motion. The only symptoms suggestive of a meniscal tear were the subjective complaints of locking, which did not appear until March 26, 2009. It was submitted that the preponderance of evidence supported the decision of the WCB.

Analysis:

The issue before the panel is whether the worker is entitled to wage loss benefits beyond August 11, 2009. The key question concerns whether the worker’s right knee PCL tear and horizontal medial meniscal tear which led to arthroscopic surgery on December 10, 2009 are related to the workplace accident of February 10, 2009. In order for the appeal to be successful, the panel must find that surgery was required because of the injury which occurred at work on February 10, 2009. After reviewing the evidence as a whole, we find on a balance of probabilities that the surgery was not required as a result of the injury sustained in the workplace accident and accordingly, the worker is not entitled to wage loss benefits beyond August 11, 2009.

In the panel's opinion, the injury suffered by the worker on February 10, 2009 was limited to a right knee strain and that the other pathology which led to the need for surgery was neither caused nor aggravated/enhanced by the slip and fall work accident. In coming to this conclusion, the panel relied on the following:

  • At the hearing, the worker stated that initially after the fall, his knee was red and it began swelling mainly underneath the kneecap on the right side. The swelling progressed right around the whole knee afterwards. His knee also became discoloured with blue bruising, again mainly on the outside right aspect of the knee. The worker's evidence was that he applied ice to reduce the swelling.
  • The panel notes, however, that at the time of the worker's first attendance with his physician on February 13, 2009, the written report indicates no swelling, no erythema, no heat, the ligaments were good and there was no pain with meniscal testing.
  • November 4, 2009 correspondence from the treating surgeon indicates that effusion would be expected after a PCL rupture, but not necessarily with a meniscal tear.
  • Given the absence of swelling and the identified anatomical location of swelling and discoloration as the lower outer aspect of the right knee, the panel finds that the evidence does not support that the worker suffered a PCL tear at the time of the workplace accident.
  • The treating surgeon's opinion left open the possibility that a meniscal tear occurred, despite the absence of swelling three days after the accident. The difficulty then was the fact that the worker's attending physician noted no pain with meniscal testing.
  • Following the hearing, the panel asked the attending physician to outline his usual practice regarding knee examinations. In his response, the physician described a thorough knee examination which included provocative testing specifically for meniscal injury. Although it was submitted at hearing that the worker has a high pain threshold, the panel is not convinced that this would result in a negative provocative test for meniscal injury.
  • The first report of "classic" meniscal tear symptoms did not occur until March 26, 2009 when the worker reported knee locking with pivoting to his attending physician.
  • The operative report dated December 10, 2009 (obtained post-hearing) indicated an extensive horizontal cleavage tear, which is more suggestive of a degenerative rather than acute etiology.
  • Given the absence of swelling, negative meniscal testing, and no report of locking until late March, 2009, it is difficult for the panel to find that an aggravation or enhancement of a pre-existing meniscal tear occurred on the accident date.

The panel therefore finds on a balance of probabilities, that neither the worker’s right knee PCL tear nor the horizontal medial meniscal tear which led to arthroscopic surgery on December 10, 2009 are related to the workplace accident of February 10, 2009. It follows that the worker is not entitled to benefits beyond August 11, 2009. The worker's appeal is dismissed.

Panel Members

L. Choy, Presiding Officer
A. Finkel, Commissioner
M. Day, Commissioner

Recording Secretary, B. Kosc

L. Choy - Presiding Officer

Signed at Winnipeg this 8th day of June, 2011

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