The employer and insurer appeal from the compensation judge’s finding that the employee’s bilateral knee condition was related to his admitted work injury of April 25, 2007, and from her award of continuing temporary total disability benefits.  We affirm.

Markus Vandenbosch was employed by Waste Management, Inc. on April 25, 2007, when he was injured on the job.

The employee began working for the company in 2003.  His job title was driver but his primary duties were to work on a route with a driver.  He would ride on the back of a truck, pick up garbage cans, and empty them into the truck.  He worked an eight hour day but frequently worked overtime.  The employee stood for the entire route, standing on a small platform at the back of the truck.  He jumped off to pick up and empty a can and then jumped back on the platform to the next stop.  The employee testified that he made about 1,000 stops a day and that he had no physical problems doing the job.

Medical records in evidence indicated the employee had a work injury to his right knee in 1992.  He underwent what was identified as a “partial posterior horn meniscectomy roughly 5% and plica resection.”  There is no evidence of any subsequent treatment for the right knee.  In 1995, the employee slipped on a wet floor in a restaurant and fell.  He complained of left knee pain, was diagnosed with a “left knee upper tibial contusion,” and was treated in an emergency room with ice and pain relievers.  There are no records of any subsequent treatment to his left knee.

The employee also had a head injury at an early age, resulting in developmental disabilities.  The QRC and the employee’s mother testified that the employee was unable to read or write and testified the employee’s memory, comprehension, and ability to communicate were impaired.

On April 25, 2007, the employee was standing on the platform at the back of the truck when the driver drove too close to a telephone pole.  The employee was unable to jump off in time and was crushed between the truck and the pole.  At the hearing, the employee stated, “All I remember is that I fell down on my face on the ground.”

The employee was seen at Fairview Ridges Hospital but was transferred to Regions Hospital on April 25 for more intensive care.  On admission, abrasions were noted on the employee’s lower extremities.  His primary pain complaints were in the right leg and in his low back.  After evaluation, the physicians involved in his case concluded the employee had deep venous thrombosis (DVT) in his right leg.  An additional initial diagnosis was L4-5 radiculopathy but the final diagnosis was that of lumbar plexopathy.

The parties stipulated at the hearing that the employee sustained a lumbar plexopathy as a result of the work injury and stipulated that the employee had reached maximum medical improvement for this condition.  The parties are also in agreement that the employee is at maximum medical improvement for the DVT in his right leg.  The dispute at the hearing was whether the employee suffered knee injuries on April 25, 2007.

The QRC, Nikki Vader, testified at the hearing that she began working with the employee on May 8, 2007, when he was in Regions Hospital.  She stated further that the employee was complaining of knee problems when she first started working with him.  A chart note of that date from Regions noted that, “his left leg is giving out.”  The chart notes also indicate that the employee’s left leg gave out and he fell in the hospital on May 15, 2007.

Because of his left leg problems, he was referred for an orthopedic consultation and saw Dr. Randy Twito on June 5, 2007.  Dr. Twito noted “the left knee has continued to buckle and have fairly sharp intermittent pain.”  Dr. Twito recommended “an MRI to evaluate for intraarticular pathology such as torn meniscus.”

An MRI was done on June 12, 2007, but through error, the MRI was done on the right leg and not the left.  The right knee MRI was read as showing “a tear in the body of the medial meniscus extending to the inferior articular service.”  The MRI also showed “extensive soft tissue edema.”

The employee returned to Dr. Twito on June 14, 2007.  Dr. Twito noted the error in scanning the right knee and commented with regard to the results of the right knee MRI that “the scan is consistent with medial meniscus tear and soft tissue edema from a crush injury.”  Dr. Twito continued to recommend an MRI of the left knee.

The left knee MRI was done on June 25, 2007.  The radiologist’s impression was:

At the request of the employer and insurer, the employee was evaluated by Dr. Robert Barnett on April 10, 2008.  Examination of the left knee was noted to be normal except for patellofemoral crepitation.  With regard to the left knee, Dr. Barnett diagnosed a “strain and contusion second to the injury April 25, 2007, resolved.”  It was Dr. Barnett’s opinion that the “changes involved in the patellofemoral and medial compartment” were degenerative in nature, preexisting, and not related to the work injury.  His opinion was the same with respect to the right knee.  Dr. Barnett concluded that the employee was at maximum medical improvement for the April 25, 2007, work injury.

The employer and insurer filed a Notice of Intention to Discontinue Benefits on August 15, 2008, seeking to discontinue temporary total disability benefits because the employee had reached maximum medical improvement with the service of Dr. Barnett’s report and that 90 days had expired since that service.  An Objection to the Discontinuance was filed August 22, 2008.

Dr. Twito wrote a report dated August 25, 2008, at the request of the employee’s attorney.  In it, Dr. Twito stated:

This matter was heard by Compensation Judge Peggy A. Brenden on October 23, 2008.  In her findings and order, the compensation judge determined that the “April 25, 2007, work injury is a substantial contributing factor in the bilateral meniscus tears sustained by the employee.”  The compensation judge also found that the left knee surgery proposed by Dr. Twito was reasonable and necessary and that the employee was not at maximum medical improvement.  The employer and insurer were ordered to continue to pay temporary total disability benefits.  The employer and insurer appeal.

The employer and insurer argue that the compensation judge erred in determining that the employee’s work injury was a substantial contributing factor in the bilateral meniscus tears.  They contend the finding is not supported by substantial evidence and that the compensation judge improperly shifted the burden of proof on this issue to the employer and insurer.

According to the employer and insurer, substantial evidence does not support the compensation judge’s decision because there is no evidence to connect the work injury to any injury to the knee.  Dr. Twito did not provide an explanation as to the mechanics of how a crush and fall led to knee problems.  Further, the employee provided no testimony of a specific trauma involving his knees at the time of his injury.

As the employee points out, however, this court has held that the lack of an explanation of the mechanics of the injury does not render the medical expert’s opinion on causation to be without foundation.  Henchal v. Federal Express Corp., No. WC07-212 (W.C.C.A. Jan. 30, 2008).  Dr. Twito’s treatment of the employee, including his review of the MRI scans taken of the employee’s knees, provide foundation for his opinion.  Grunst v. Immanuel-St. Joseph Hosp., 424 N.W.2d 66, 40 W.C.D. 1130 (Minn. 1988).

The inability of the employee to explain the mechanics of his injury is not significant in the context of this case.  Acceptance of the argument by the employer and insurer would also call into question the causation of the employee’s plexopathy or DVT, neither of which would be explained by the employee’s simple statement that he fell on his stomach.  Medical causation is generally not in the province of an injured employee.  For this reason, the parties submitted the opinions of two medical experts, Dr. Twito and Dr. Barnett.  The compensation judge accepted the opinion of Dr. Twito.  Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).

We find substantial evidence in the record which supports the opinion of Dr. Twito.  The employee’s uncontroverted testimony was that his job required him to jump off and on a platform at the back of the truck 1000 times a day and yet he had no physical problems doing the job.  The initial medical records from Regions showed abrasions on the employee’s legs, demonstrating trauma to that part of the employee’s body.  The hospital records contain a number of references to the employee’s left leg buckling and giving out.  There is no evidence of this occurring before the work injury.

Most importantly, however, the argument of the employer and insurer ignores Dr. Barnett’s opinion.  In his April 10, 2008, report, Dr. Barnett reported one of his diagnostic impressions as being “left knee strain and contusions secondary to injury April 25, 2007, resolved.”  His conclusion was clearly that the trauma of the work injury resulted in an injury to the left knee, even though he did not explain the mechanics of that injury.  The issue then is not whether the employee had a knee injury, but whether the extent of that injury included bilateral meniscus tears.

On that issue, the compensation judge weighed the records of the employee’s treatment for his knees before the injury, the employee’s testimony about his job and his condition before the injury, the testimony of the QRC, the medical records, and the opinions of Dr. Twito and Dr. Barnett.  We find no merit in the argument that in considering this evidence, the compensation judge improperly shifted the burden of proof to the employer and insurer.

According to the brief of the employer and insurer, “the memorandum makes it apparent the compensation judge inappropriately shifted the burden of proof to the employer and insurer to prove the employee did not sustain injuries to his knees.”  We turn then to a consideration of the compensation judge’s decision and memorandum.  The memorandum must be read in the context of the findings.  The findings detail the evidence which the compensation judge found persuasive in accepting the employee’s claim.  Because the compensation judge did not find the employer and insurer’s evidence persuasive, that evidence was not detailed in the findings but was addressed in the memorandum.  We find nothing in the memorandum suggesting the compensation judge improperly applied the burden of proof in this case.  The memorandum is simply an explanation as to why the employer and insurer’s position was not accepted by the compensation judge.

The determination of the compensation judge that the employee’s work injury was a substantial contributing factor in his bilateral meniscus tears is supported by substantial evidence.  The employer and insurer did not dispute the finding that the surgery recommended by Dr. Twito was reasonable and necessary or the finding that the employee was not at maximum medical improvement because of the need for surgery.

Accordingly, the compensation judge’s decision is affirmed.