Taher, Inc., and Indiana Insurance appeal from the judge’s finding that the employee sustained a work-related injury while employed by Taher.  We reverse.

The employee began work for Dairy Farmers of America [DFA] in 1993.  On May 14, 2009, the employee was extracting a box of cheese, weighing approximately 40 pounds, from a box maker machine when she felt a sharp pain in her low back.  She was originally diagnosed with a lumbar sprain/strain and received physical therapy.

In July of 2009, the employee was seen by orthopedist Dr. Robb Rutledge, who restricted her to sedentary work.  An MRI performed on August 20, 2009, showed a broad-based disc bulge at L3-4 impinging on the L3 nerve root on the left, degenerative disc disease, and facet degenerative joint disease with severe central canal stenosis at L3-4 and mild to moderate central canal stenosis at L4-5.

DFA assigned the employee to light-duty work for several months, but, in August 2009, she was terminated when DFA no longer had work within her restrictions.

The employee was seen on October 6, 2009, by Dr. Edward Santos, an orthopedic surgeon, complaining of pain in the low back and left buttock.  Dr. Santos attributed the employee’s back pain to stenosis at L3-4 and severe bilateral facet arthritis at L3-4 and L4-5.  He restricted the employee from all work and recommended an epidural steroid injection, which was performed on October 16, 2009.  Dr. Santos’s office notes of November 17, 2009, indicate that the injection had completely alleviated the employee’s leg symptoms but that she still complained of low back pain.  At that time, he encouraged the employee to continue with “nonoperative treatment.”

Subsequently, on December 8, 2009, Dr. Rutledge restricted the employee to limited bending and twisting and no lifting over 10 pounds.

In January of 2010 the employee began a job search in accordance with a rehabilitation plan.  She returned to Dr. Rutledge on February 23, 2010, complaining of left-sided low back pain with radiation down the left leg.  At that time, the employee reported that, if she had to bend, twist, or lift, her pain would worsen.  Dr. Rutledge restricted the employee from work and referred her for another epidural injection.  He also noted that the employee might be a surgical candidate.

In April of 2010, the employee underwent an independent medical examination by Dr. Thomas J. Raih, at the request of DFA and its workers’ compensation insurer.  At that time, Dr. Raih diagnosed the employee as having preexisting multilevel lumbar degenerative disc disease, which had been temporarily aggravated by the 2009 work injury, and a disc protrusion at L3-4 caused by that same injury.

The epidural injection recommended by Dr. Rutledge was not administered until May 7, 2010.  On May 25, 2010, Dr. Rutledge opined that the employee was almost back to normal, and he released her to work four to six hours per day, with a 20-pound lifting restriction.  On June 29, 2010, Dr. Rutledge noted that the employee could work eight hours per day with a 20-pound lifting limit and that she should avoid excessive twisting and bending.  She was hired and worked briefly in a retail store in mid-August of 2010 but found the physical demands of that job too hard on her back.  On August 31, 2010, she was hired by Taher, Inc., preparing and serving food to children in a school setting.  She worked full-time for the first two weeks, but Taher then changed her schedule to four hours a day, five days a week.  Her job did not require any lifting, but she had to stand throughout her work shift.

On October 5, 2010, the employee told Dr. Rutledge that the May 7, 2010, epidural had helped for two or three months but that, over the past couple of months, her pain had returned to where it was before the injection.  The doctor limited her to four hours of work a day with a 10- to 20-pound lifting limit and referred her to Dr. Santos to discuss the possibility of surgery, opining that “the injection of cortisone having helped her would be a preview of what might happen if she has a decompression or fusion or both.”

The employee saw Dr. Santos on January 25, 2011, complaining of low back pain and bilateral lower extremity pain.  In a letter to Dr. Rutledge, Dr. Santos stated that the employee “has a diagnosed case of severe L4-5 and L5-S1 stenosis.”  He reviewed her 2009 MRI and noted that it clearly showed severe stenosis of the L4-5 level and moderate stenosis at the L5-S1 level with both levels exhibiting severe facet arthritis on both sides.  He opined that the employee had exhausted nonoperative measures and was a candidate for an L4-5 and L5-S1 decompression and transforaminal lumbar interbody fusion.

A second MRI was performed on February 16, 2011.  The radiologist noted that the right L3-4 central stenosis was slightly increased, the left L4-5 foraminal stenosis was slightly increased, and the central stenosis at L3-4 was mildly increased, when compared to the 2009 scan.

On April 11, 2011, in a letter to Taher, Dr. Rutledge stated that the employee was suffering from a chronic back condition and should be excused from work.  She has not worked since that time, and Dr. Rutledge agrees with Dr. Santos’s recommendations regarding surgery.  Dr. Rutledge wrote a letter to the employee’s attorney on February 10, 2011, stating that the employee’s symptoms “are the result of her work injury May 14, 2009.”

In August of 2011, Dr. Raih conducted a review of the employee’s medical records and deposition testimony and issued an addendum report, stating that only the disc protrusion on the left at L3-4 was related to the 2009 injury.  He went on to opine that the employee had sustained a second injury while employed at Taher and that responsibility for the recommended surgery should be apportioned 50% to the Taher injury and 50% to her preexisting degenerative condition.  He also opined that “surgical treatment . . . is based on the longstanding, chronic degenerative disc disease and development of spinal stenosis and spondylolisthesis and not the injury of May 14, 2009.”

The employee underwent an independent medical examination by Dr. Terry Hood on January 11, 2012, at the request of Taher and its workers’ compensation insurer.  Dr. Hood diagnosed preexisting lumbar stenosis and a disc protrusion at L3-4.  He concurred that the proposed fusion surgery was reasonable to treat the employee’s current condition and apportioned the need for that surgery 30% to the employee’s prior work as a cabinet maker, 60% to the employee’s 2009 work injury, and 10% to the employee’s weight and smoking history.

This case proceeded to hearing, and, in findings and order filed on October 23, 2012, the compensation judge found, in relevant part, that the employee had sustained a Gillette-type^[1] injury to her low back on April 11, 2011, while employed by Taher.  The judge further concluded that the 2011 injury was a substantial contributing cause of the employee’s current condition and need for medical treatment, and she apportioned responsibility for temporary total disability benefits from April 15, 2011, and for the proposed fusion surgery on a 50/50 basis between the 2009 injury and the 2011 injury.  Taher and its insurer appeal.

On appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”  Minn. Stat. § 176.421, subd. 1 (2012).  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

On appeal, Taher and its insurer contend that substantial evidence does not support the judge’s finding that the employee sustained a Gillette injury culminating on April 11, 2011.  We agree.

The compensation judge adopted the opinion of Dr. Raih, as set forth in his report of August 12, 2011, as to the occurrence of the disputed Gillette injury.  The judge found that Dr. Raih “noted that the changes in the employee’s condition after she began work at Taher supported a conclusion that the employee suffered a work injury with that employer.”  In actuality, Dr. Raih stated, “based on the additional information provided, in my opinion, Ms. Huebbe did sustain a second injury while employed at [Taher].”  Similarly, he apportioned 50% of the responsibility for the recommended surgery to “the injury sustained at [Taher]” based on “the new information provided.”

Dr. Raih’s 2011 report references “subsequent and additional medical records” that he reviewed, citing to some records related to treatment prior to the employee’s work injury at DFA, and some from the period between the date of injury and his exam of the employee on April 29, 2010.  He went on to specifically note the epidural injection on May 7, 2010, Dr. Santos’s recommendation for surgery on January 25, 2011, and the subsequent MRI on February 16, 2011.

Dr. Raih also stated in his addendum report that he had reviewed the employee’s deposition testimony and other “updated information.”  Dr. Raih’s report, however, provides no explanation as to the doctor’s understanding of when the employee began work at Taher, how long she worked at Taher, or even what her work activities involved.^[2]  Similarly, Dr. Raih provided no explanation as to whether the employee had sustained a specific or a Gillette injury while at Taher or just when that injury would have occurred.  The other medical records also fail to support the conclusion that the employee sustained a Gillette injury while employed by Taher.  The comparison of the 2009 MRI and the 2011 MRI noted only mild to moderate changes, and no doctor has related those changes to an injury at Taher.

The question of a Gillette injury depends primarily on the medical evidence.  Steffen v. Target Stores, 517 N.W.2d. 579, 50 W.C.D. 464 (Minn. 1994).  Here, the judge relied on Dr. Raih’s narrative opinions concerning the nature and extent of the employee’s work injury at Taher.  A judge’s choice between expert opinions is usually upheld unless the facts assumed by the expert are not supported by the evidence.  Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).  However, in this case, it is unclear precisely what facts were assumed by Dr. Raih in his reference to “additional information provided,” and he offered no explanation as to the basis for his conclusion that the employee sustained a work injury while at Taher.^[3]  The judge’s finding that the employee sustained a work-related Gillette-type injury while employed at Taher is therefore unsupported by substantial evidence, and we reverse.