The employer and insurer appeal from the judge’s decision that the employee was employed full-time by two employers on the date of injury and that the work injury substantially contributed to the employee’s left shoulder condition and need for the recommended surgery.  We affirm in part and vacate in part.

The employee was seen at Regions Hospital on June 26, 2003, by Dr. Ralph Bovard.  At that time, the employee reported having sustained a gunshot wound to the left shoulder while living in Ethiopia approximately 18 to 19 years earlier.^[1]  Dr. Bovard noted that the employee’s chief complaint was left shoulder pain, with a pain level of 6.  On examination, the employee was unable to elevate his arm much above 45 degrees in either abduction or forward flexion.  He also seemed unable to supinate the hand strongly or to effectively activate his biceps.  Dr. Bovard’s assessment was left proximal third humerus open fracture secondary to the gunshot wound, with chronic nonunion.  A Sarmiento brace for the left upper shoulder was prescribed, but the employee found the brace uncomfortable and felt that he had less left upper extremity function while wearing it.  Dr. Bovard noted that the employee was employed at that time, doing utility work that required pushing and pulling, with maximum lifting of up to 50 pounds.  Dr. Bovard referred the employee to Dr. Marc Swiontkowski for a surgical consultation.

The employee was seen by Dr. Swiontkowski on August 1, 2003.  This doctor also noted that the employee was currently performing manual labor, with maximum lifting of up to 50 pounds, which the doctor found to be “amazing.”  The employee had no radicular symptoms in the hand and reported that he never had burning dysesthesia.  His main complaint was of “pain in the shoulder, particularly with activity and sleeping on that side.”  Dr. Swiontkowski opined, “it is reasonable to attempt to get this to heal with a custom-angled blade plate to optimize proximal fixation and iliac crest bone graft.”  Surgery was scheduled for August 10, 2003, but the employee did not go through with it.

The employee underwent physical therapy for cervical spine pain/strain at NovaCare Rehabilitation in October and November of 2004.  Treatment was not directed to the employee’s left shoulder, but, in a progress note dated December 15, 2004, the physical therapist recorded that the employee had a history of a gunshot wound to the left shoulder, with severely restricted range of motion and strength.^[2]

The employee was working as a utility laborer for HMS Host Corporation [the employer] on March 31, 2009, when he slipped on a wet floor while carrying a 50-pound carton of pop.  He landed on his left side and had pain in the low back, left arm, and left shoulder.^[3]  He treated with Dr. Thomas Lange at HealthPartners in Regions Hospital on April 1, 2009.  Dr. Lange noted that the employee had been working for the employer for 10 years and had done well in spite of a chronic proximal humeral fracture nonunion.  The doctor diagnosed a sprain of the humerus, nonunion on the left.  An x-ray taken that day showed an old unhealed fracture involving the proximal humeral diaphysis.  The radiologist reported no acute injury and that this x-ray did “not appear significantly changed compared to 2003.”^[4]

When seen by physician assistant Jackie Schechinger on April 7, 2009, the employee was complaining of significant pain in the neck and left shoulder, radiating down to his left hand and fingers.  The employee described this “as a burning-type pain with associated tingling.”

When seen by neurosurgeon Dr. Jeff Golan on May 15, 2009, for neck and low back pain, the employee reported having pain going down the left arm “involving the whole arm, forearm and fingers.”  The doctor stated that the employee “does not believe that the symptoms in the left arm are related to his neck although they seem to have been worse ever since his fall.”

Dr. Golan referred the employee to physiatrist Dr. Richard Timming, who examined the employee on May 21, 2009.  Dr. Timming recorded the gunshot wound history, with the employee reporting that he had been able to function at his job, despite his shoulder condition, until the work injury.  The employee told Dr. Timming that he was no longer able to flex his shoulder and that he had lost strength and had more weakness.  On exam, the doctor found no flexion above 5 degrees, and he diagnosed a possible rotator cuff tear.  However, an MRI performed on June 1, 2009, was negative for a rotator cuff tear.

According to a physical therapy progress note of June 23, 2009, the employee was “confused as to why he was able to use his L shoulder to help lift 50 lb objects prior to his accident and that the arm is essentially useless now with constant pain.”

The employee was seen by Dr. Lange again on July 21, 2009.  At that time, Dr. Lange opined that the employee had become significantly limited by the nonunion of the humerus.  “For many years, it was painless, but I believe in my interpretation of the events, that the injury resulted in somehow breaking up some adhesions or some of the fibrous tissue that was keeping the nonunion relatively painless.”  The doctor predicted that, if they could get the employee “healed in his arm,” it would be easier to address his neck, shoulder, and low back issues.  He referred the employee to Dr. Peter Cole.

Dr. Cole examined the employee on August 10, 2009.  The employee reported no pain at that time, except when he tried to move his left shoulder.  The doctor noted that the employee had no function in the shoulder.  The doctor also noted,

The employee was examined by Dr. Buck on August 27, 2009.  On exam of the employee’s shoulder, the doctor found very limited “shoulder forward flexion, abduction approximately 10 to 20 degrees with forward flexion and shoulder abduction.”  X-rays taken that day were interpreted by Dr. Buck as showing no changes from the x-rays in 2003.  He recommended the two-stage reconstruction surgery to try to alleviate some of the employee’s pain.

The employee returned to Dr. Timming on September 17, 2009.  Dr. Timming noted the gunshot wound to the employee’s left humerus, with non-union, and also recorded a history of the work injury “with increasing pain and weakness.”

On October 5, 2009, the employee again discussed surgery with Dr. Buck, who noted that the employee wanted to proceed with the two-stage surgery in spite of the risks.  The first stage of the procedure was scheduled for mid-October 2009, but the employer and insurer denied liability for that surgery.

The employee filed a medical request on December 18, 2009, seeking approval of the recommended left arm surgery.  The employer and insurer responded by questioning the causal relationship between the employee’s work injury and the need for the recommended surgery.

The employee was examined by independent medical examiner Dr. Stephen Barron on January 20, 2010.^[5]  In his report of January 26, 2010, Dr. Barron opined that the nonunion was “a totally pre-existing condition,” which had resulted from the gunshot wound 18 to 20 years earlier.  It was his opinion that the 2009 work injury was not a substantial contributing cause of the nonunion or the need for surgery to correct that condition.  He did agree that the recommended surgery was reasonable and necessary to treat the nonunion.

When the medical request proceeded to hearing, the issues were identified as whether the employee had sustained an injury to his left shoulder on March 31, 2009, the nature of that injury, and whether that injury was a substantial contributing cause of the employee’s need for the proposed surgery.  In findings and order filed on March 19, 2010, the compensation judge found that, in addition to working for the employer, the employee was employed full-time by a restaurant on the date of injury, and that the work injury was a substantial contributing cause of the employee’s need for the proposed surgery.  The employer and 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 (2008).  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).

The employer and insurer contend that the judge’s finding that the employee was employed by two employers on the date of injury was not relevant to the issues before the court.  The employee did not respond to this argument in his brief.  Because the issue of whether the employee was employed by two employers was not raised as an issue at hearing and was not relevant to the issue at hand, we vacate that finding.

The judge found that the recommended surgery was reasonable and necessary “in the attempt to cure and relieve the employee from the effects of the March 31, 2009, personal injury” and that the work injury was a substantial contributing cause of the employee’s need for that surgery.  In his memorandum, the compensation judge stated, “at a minimum, the employee has a nonunion of the humerus and that condition was aggravated by the trauma [work injury].”  “The compensation judge accepts the substance of the records of Drs. Cole and Buck regarding the occurrence and significance of the left shoulder injury at work.”  The employer and insurer contend that the judge’s conclusion, as to the work-related aggravation, is not supported by substantial evidence and “is not supported by the majority of doctors who treated the employee after his March 31, 2009, injury.”  We are not persuaded.

The employee went without medical treatment for his left shoulder condition from 2003 until the 2009 work injury.  During that time, he worked successfully in a job that required him to lift up to 50 pounds.  After the work injury, the employee was found by Dr. Buck to have only 10 to 20 degrees of forward flexion and abduction, as opposed to 45 degrees in 2003.  Dr. Cole noted that the employee had no function in the shoulder when he saw the employee in August of 2009.  Drs. Timming and Lange noted a decrease in left shoulder function after the work injury.  Medical providers also noted increasing pain in the left shoulder following the 2009 work injury, including Dr. Lange, physician assistant Schechinger, Dr. Timming, and Dr. Buck.

The employer and insurer are correct in noting that neither Dr. Buck nor Dr. Cole opined specifically that the work injury was a substantial contributing cause of the employee’s need for surgery.  But Dr. Buck’s records do reflect that the employee had worked for the employer “for approximately 10 years and has done well in spite of a chronic proximal humeral fracture nonunion” and that the employee had increased pain and decreased function in the left shoulder after the 2009 work injury.  His records also indicate that the surgery was recommended to improve the employee’s level of pain.

Similarly, Dr. Lange provided an explanation as to how the work injury had caused increased pain in the employee’s left shoulder/arm.  In that same office note of July 21, 2009, Dr. Lange stated that the employee “seemed to be in an agreeable frame of mind to consider repair of this nonunion.  The pain from the nonunion has gone on for about 4 months since the injury.”  It is reasonably inferable, from this office note, that the surgery was proposed to reduce or alleviate the pain that the employee had been experiencing since the work injury.

While the employer and insurer also contend that Drs. Buck and Cole lacked adequate foundation for their opinions, they have given no specific examples of alleged deficiencies.  A judge’s choice between expert opinions is generally 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).  There is no evidence that Dr. Buck, at least, relied on any facts not supported by the evidence.^[6]

Finally, the employer and insurer contend that medical records since March 31, 2009, refute the judge’s conclusion that the “employee has had significant symptoms in the left shoulder since the occurrence of the injury.”  We are not convinced.

In May of 2009, Dr. Timming noted that the employee had been able to function in his job, despite a humerus nonunion, until the time of his work injury.  In July of 2009, Dr. Lange noted that the employee’s arm had been painless for many years and implied that the employee had experienced pain continuously subsequent to his work injury.  Dr. Cole noted that the employee had no function in his shoulder and that it hurt to try to move it.  In August of 2009, Dr. Buck found that the employee had only 10-20 degrees of abduction in the right shoulder, whereas medical records in 2003 reported abduction at 45 degrees, and, in September of 2009, Dr. Timming noted that the employee had been experiencing increased pain and weakness since the work injury.  Substantial evidence clearly supports the judge’s conclusion that the employee has continued to experience significant, increased left shoulder symptoms since the date of injury.

The employee’s testimony, the lack of medical treatment for his shoulder condition for six years prior to the work injury, the evidence of increased pain and loss of function after the work injury, and the opinions of Drs. Lange and Buck provide substantial evidence to support the judge’s decision that the work injury aggravated the preexisting nonunion of the left humerus and was a substantial contributing cause of the employee’s need for surgery.  The judge’s findings in this regard are therefore affirmed.