The employee appeals from the compensation judge’s finding that the bariatric surgery recommended by the employee’s treating physicians “is not causally related to and is not reasonable or necessary to cure or relieve the effects of the employee’s work related left knee injury of June 8, 2006.”  We affirm the judge’s determination that the proposed bariatric surgery is not reasonable or necessary, but we reverse the judge’s finding on causation.

Nicole Bauer [the employee] began working as a truck driver for FedEx Freight East in May of 2005.  Her main job duties included driving a semitrailer truck and unloading it either manually or with a pallet jack.  On June 8, 2006, while lifting and moving a table out of her delivery truck, the employee twisted awkwardly and sustained an injury to her left knee.  The employee had no previous history of injury to her left knee at the time but did have a long history of being overweight and a documented medical history of morbid obesity since at least 2001.  At the time of her injury, the employee was not quite thirty-two years old, and the employer was self-insured against workers’ compensation liability.

The employee immediately reported the injury to her employer and sought medical treatment at the St. Mary’s Medical Center in Duluth.  She was regularly followed thereafter at Duluth Clinic Occupational Medicine, where she began a program that included rest, medications, physical therapy, and activity modification.  Improvement was slow, and the employee was referred for an MRI of the left knee and an orthopedic consultation with Dr. Troy Erickson.  At that exam, on July 18, 2006, Dr. Erickson noted the employee’s history of obesity and her current weight of 262 pounds.  He reviewed the employee’s x-rays and her recent MRI and assessed a torn left ACL, with bone bruising of the tibia and femur and medial and lateral meniscal tears.  The doctor recommended that the employee continue with physical therapy to improve her range of motion.

By September 12, 2006, Dr. Erickson noted that the employee had progressed in her rehabilitation, and he recommended proceeding with surgery.  The following week, at her preoperative physical, the employee weighed 299 pounds.  The employee was cleared for surgery, and on October 5, 2006, Dr. Erickson performed an ACL reconstruction, along with a partial medial meniscectomy, a minimal lateral meniscectomy, and a patellar chondroplasty.

Following surgery, the employee began another course of physical therapy, but on December 8, 2006, she fell when her knee buckled, sustaining a fracture of her left patella.  She was then referred to Dr. Jefferson Davis, who, on December 12, 2006, performed an open reduction and internal fixation of the left patella fracture.

In follow-up with Dr. Davis on March 21, 2007, the employee reported a grinding sensation in her knee, and Dr. Davis concluded that this represented some possible hardware impingement.  In accordance with that assessment, on March 27, 2007, the employee underwent another surgical procedure, to remove the hardware in the patella and an arthroscopy was also performed.  The ACL appeared to be intact, but the patellofemoral joint was noted to have extensive synovitis and chrondral damage, so a chondroplasty was performed along with a lateral release.

Following her third knee surgery, the employee re-entered physical therapy and continued to have moderate discomfort.  On September 12, 2007, Dr. Davis administered a Kenalog injection to the employee’s left knee, from which the employee reported only mild symptom improvement for about a week.  Thereafter she underwent a series of Supartz injections, with no relief of her symptoms.  On February 6, 2008, the employee underwent another surgery, described as a patellar chondroplasty and lateral release.

By late April of 2008, Dr. Davis concluded that arthroscopic treatment for the employee’s condition had been exhausted, and he requested a consultation with Dr. Michael Gibbons.  On June 3, 2008, the employee saw Dr. Gibbons and complained of a cracking and grinding sensation in her knee.  She also complained that her knee would occasionally give out due to pain.  The doctor noted the employee’s history of obesity and her current weight of 318 pounds.  He related her ongoing problems to post-traumatic degenerative changes of her patellofemoral joint.  He explained to the employee that her clinical situation was very difficult, because he considered her too young to consider total knee arthroplasty and her obesity only made the problem worse.  He went on to discuss bariatric surgery with her, and, because he thought that weight loss “is probably the most important thing that she can do for her knee,” he strongly encouraged her to seek intervention.  Although concluding that the employee was not a candidate for total knee arthroplasty, Dr. Gibbons thought that she might benefit from a patellofemoral arthroplasty, and he referred her to Dr. Thomas Kaiser for evaluation.

Dr. Kaiser first examined the employee on July 23, 2008.  He noted that, because of inactivity since her initial injury, she had gained weight and was now at 300 pounds.  The doctor assessed a possible re-tear of her medial meniscus, along with “significant patellofemoral degenerative change with maltracking.”  He recommended an MRI of the left knee, additional x-rays, and a weight loss clinic evaluation to see if she was a candidate for any sort of weight loss management because of her morbid obesity.

The employee obtained the recommended MRI and x-rays, and she returned to see Dr. Kaiser on August 13, 2008.  The employee had evidently been evaluated for weight loss surgery but had learned that the process takes a period of time.  She therefore asked Dr. Kaiser if something could be done for her knee that would allow her to be more active.  The doctor continued to assess significant degenerative change in the patellofemoral joint, and he emphasized the need for the employee to go through a complete workup for weight loss surgery.  In discussing potential knee surgery and weight loss surgery with the employee and her QRC, Amy Brown, Dr. Kaiser stated:

On January 9, 2009, the employee was examined for the self-insured employer by orthopedic surgeon Dr. Michael D’Amato.  In a report issued January 16, 2009, the doctor opined that the employee’s left knee condition and the treatment thus far provided for that condition had been reasonable, necessary, and causally related to the employee’s work injury.  But Dr. D’Amato concluded that the employee’s morbid obesity clearly pre-existed her work injury and was the sole cause of her need for weight loss.  In his opinion, the employee’s work injury did not play any role in the development of her morbid obesity, and therefore any treatment for her morbid obesity would be the result of her pre-existing condition.  At the same time, it was also his opinion that “weight loss . . . is an extremely important issue with regards to treatment of her left knee symptoms.”  He believed that her morbid obesity contributed to her ongoing left knee symptoms and that weight loss might result in significant improvement.  While Dr. D’Amato believed that the employee required additional medical treatment, particularly with regard to weight loss, he did not believe that a patellofemoral joint replacement was reasonable and necessary for a 34-year old individual with morbid obesity.  It was his opinion that “weight loss should be obtained first and this may help relieve her symptoms to the point where an arthroplasty procedure can be avoided altogether.”  Finally, Dr. D’Amato did not believe that the employee had reached maximum medical improvement [MMI] from her June 8, 2006, injury.

The employee saw Dr. Kaiser in follow-up on March 6, 2009, at which time she reported increasing knee pain since her last visit.  She informed the doctor that she had been working with a dietician about the prospect of obtaining bariatric surgery but that she would still require another three to four months of sessions before surgery would be considered.  The employee expressed frustration with her limited activity level and discomfort and wondered what she could do.  Dr. Kaiser again discussed possible surgical options, including an arthrotomy with lateral facetectomy and possibly a patellofemoral joint replacement.  Dr, Kaiser included this treatment plan on his report of workability.

The employee did not return to see Dr. Kaiser for over a year.  In the meantime, on December 2, 2009, the self-insured employer arranged for the employee to be examined by Dr. Daniel Leslie, a specialist in laparoscopic and bariatric surgery.  As part of his evaluation, Dr. Leslie reviewed the employee’s medical records, including records from a weight loss surgery program in Duluth.  The employee informed Dr. Leslie that she had consulted with Dr. Tracy Pitt, who had recommended that she undergo a gastric bypass operation.  The employee reported also that she had undergone most of the preoperative requirements to qualify for the surgery but she had subsequently lost her insurance because she was not physically working for FedEx and was therefore unable to proceed.

Dr. Leslie noted that the employee had a documented history of morbid obesity since at least July of 2001.  He agreed with Dr. D’Amato that her morbid obesity was not caused by her knee injury, because she already had that diagnosis prior to her knee injury.  Still, it was his opinion that, “[b]ecause of [the employee’s] knee injury and inability to sustain activity and exercise at the same level as she had prior to the injury, certainly weight gain since the injury and inability to lose weight is substantially contributed to by the knee injury.”  Moreover, “[g]iven the nature of [her] weight and knee injury, she clearly needs to lose weight in order to optimize her outcomes after a future knee operation.”  Dr. Leslie did take issue with the particular bariatric surgery evidently recommended by the employee’s treating physicians.  While agreeing that “weight loss surgery is certainly reasonable and most likely necessary for [the employee],” he did not believe that a laparoscopic Roux-en-Y Gastric Bypass (RYGB) operation was a good option for the employee.  Dr. Leslie stated that all patients who undergo RYGB have a risk of marginal ulcer, which is a form of peptic ulcer disease related to the gastric bypass anatomy.  In the employee’s case, he opined, the risk was even higher because of her history of tobacco use in combination with her need for ibuprofen to address her knee pain.  As a better option, Dr. Leslie suggested a laparoscopic adjustable gastric band operation, which does not entail the same long-term risk of marginal ulcer.

Eight months later, on August 6, 2010, the employee returned to see Dr. Kaiser.  The doctor noted at that time that weight loss surgery had been denied by workers’ compensation and, because the employee no longer had medical insurance, she could not go forward with that surgery.  In addition, Dr. Kaiser no longer believed that a patellofemoral arthroplasty would be adequate for the employee.  He now concluded that her osteoarthritis was tricompartmental in nature and that a total knee arthroplasty would be necessary.  He continued to urge weight loss surgery for the employee, and he stated, “I really feel strongly that the weight loss surgery is going to have to come first because now my only option is a total knee and I want that to last as long as possible.”

On August 15, 2010, the employee filed a medical request for the total knee replacement recommended by Dr. Kaiser, and, without any particular specificity, for “weight loss surgery.”  In support of her claim, the employee attached only the office notes prepared by Dr. Kaiser.

The matter came on for hearing before a compensation judge on November 23, 2010.  Issues at hearing were as follows: (1) “whether the bariatric surgery recommended by the employee’s treating doctors is causally related to the employee’s work-related left knee injury of June 8, 2006,” (2) “whether the bariatric surgery recommended by the employee’s treating doctors is reasonable and necessary to cure or relieve the effects of the employee’s left knee injury of June 8, 2006,” and (3) “whether the left total knee replacement surgery recommended by Dr. Thomas E. Kaiser is premature at this time.”  Evidence offered at the hearing included the employee’s testimony, records of treatment for her knee from the Duluth Clinic, and the IME reports from Drs. D’Amato and Leslie.

In a findings and order issued December 10, 2010, the compensation judge determined that “the bariatric surgery recommended by the employee’s treating physicians is not causally related to and is not reasonable or necessary to cure and relieve the effects of the employee’s work related left knee injury of June 8, 2006.”  She found also that the left total knee replacement surgery recommended by Dr. Kaiser was premature at this time.  The employee appeals.

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 (2010).  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, the employee concedes that the compensation judge could conclude that the Roux-en-Y Gastric Bypass operation proposed by her doctors was not reasonable and necessary, and she acknowledges that the judge was correct in determining that a left total knee replacement as recommended by Dr. Kaiser would be premature.  The employee argues, however, that the judge erred in finding that bariatric surgery is not causally related to the employee’s work-related left knee injury of June 8, 2006.  She argues that there is no factual basis to conclude that weight loss surgery is not reasonable and necessary to cure and relieve her from the effects of her work injury, and she contends that the procedure recommended by Dr. Leslie, upon whom the judge relied, should be adopted.  We agree, in part.

We would note first that the judge’s denial of the employee’s claim for weight-loss surgery was only a denial of the surgery “recommended by the employee’s treating physicians.”  Based on Dr. Leslie’s report, the recommended surgery was apparently the RYGB procedure.  The employee has the burden of proving that claimed medical expenses are reasonable, necessary, and causally related to the work injury.  See, e.g., Adkins v. University Health Care Ctr., 405 N.W.2d 233, 39 W.C.D. 898 (Minn. 1987).  No records from the physicians, certified nurse practitioners, or dieticians who examined or evaluated the employee in the weight loss clinic were submitted into evidence.  Absent such evidence, the judge determined, based on Dr. Leslie’s opinion, that the RYGB operation was not reasonable or necessary, and the employee concedes that this finding by the judge is supported by substantial evidence.

In her memorandum, however, the judge appears to base her denial of the proposed surgery in part on a finding that the employee’s morbid obesity is not causally related to the work injury.  The judge stated, “[t]here is no evidence in the present case that the employee’s obesity caused or substantially contributed to the left knee injury of June 8, 2006, or that the left knee injury caused or substantially contributed to the obesity.”  We agree with the employee that the origin of the employee’s obesity, or whether that obesity substantially contributed to the knee injury, is irrelevant.  It is undisputed that the employee’s left knee condition is causally related to the work injury.  It is also undisputed that the employee’s morbid obesity pre-existed the work injury.  The employer is liable, however, for any medical treatment reasonably required to cure and relieve the employee from the effects of that injury.  Minn. Stat. § 176.135, subd. 1(a).  The relevant question here is not what caused the employee’s morbid obesity, or whether that morbid obesity caused the knee injury, but whether medical treatment for the employee’s morbid obesity is reasonably required to cure and relieve the employee from the effects of her injury.  Here, Dr. Gibbons, Dr. Kaiser, Dr. D’Amato, and Dr. Leslie all agree that significant weight loss by the employee is needed to address her knee pain and problems.  Indeed, in Dr. D’Amato’s opinion, significant weight loss by the employee may even help relieve the employee’s symptoms “to the point where an arthroplasty procedure can be avoided altogether.”

In Hopp v. Grist Mill, 499 N.W.2d 812, 48 W.C.D. 450 (Minn. 1983), the employee sustained an admitted right knee injury that allegedly led to the development of a deep venous thrombosis in the right leg.  Because the employee was morbidly obese, a treating physician concluded that weight loss was essential to the treatment of the employee’s deep venous condition and recommended gastric bypass surgery for weight loss.  The employer and insurer objected to the bypass surgery, contending that the employee’s deep venous condition was due to her morbid obesity, not to her knee injury, and that the proposed gastric bypass surgery was related to her obesity and for the treatment of her health in general.  A compensation judge determined that the employee’s right knee and right leg venous conditions were causally related to her work injury, and the supreme court affirmed the compensation judge’s award of benefits related to the gastric bypass surgery.  The court noted that, while the employee’s general health would benefit from weight reduction, a medical expert had clearly stated that the gastric bypass surgery was directed primarily to the medical care of the employee’s deep venous thrombosis, which was a consequence of the work injury.

In the present case, the consequence of the employee’s work injury is a knee condition, and the medical evidence of record supports the conclusion that weight loss surgery is reasonably required to cure and relieve the employee from the effects of that condition.  While nobody denies that the employee’s morbid obesity has been a life-long condition for her, the purpose of the recommended weight loss surgery is treatment of the work injury, not treatment of the employee’s overall health.  The referrals for weight loss evaluation and treatment have primarily been prompted to treat the work-related knee condition.  Finding no substantial evidence in the record to support the judge’s causation determination, we reverse that portion of Finding 3 which holds that the bariatric surgery recommended by the employee’s treating physicians is not causally related to the employee’s work-related left knee injury of June 8, 2006.

We decline, however, to grant the employee’s request that we adopt the opinion of Dr. Leslie that a different procedure is appropriate, a procedure that apparently was neither requested nor litigated before the judge.  As previously noted, the employee did not submit into evidence any records or opinions from the medical personnel who examined or evaluated the employee in the weight loss clinic.  The burden of proof on medical claims remains with the employee, and there is no evidence in the record before us that the employee requested the surgery discussed by Dr. Leslie or that that surgery has been contemplated by her treating physicians.

To conclude, we affirm the judge’s denial of the bariatric surgery recommended by the employee’s treating physicians, we reverse her determination that that proposed surgery was not causally related to the work injury, and we decline to adopt the opinion of Dr. Leslie to the extent of awarding a surgery neither claimed nor litigated before the judge.