The employee appeals from the compensation judge’s findings that the employee’s work-related falls on April 6 and 7, 2008, did not substantially contribute to his left hip or low back condition; that the employee has no residual effect from those falls; and that he is not entitled to reinstatement of weekly indemnity benefits.  We affirm.

The employee, 66 years of age at the time of hearing, has a long history of musculoskeletal conditions.^[1]  In 1971, he sustained a work-related injury to his low back for which he underwent surgery on March 6, 1972.  That surgery, performed by Dr. Paul Van Pufflin, consisted of a laminectomy/diskectomy at L5-S1.

The employee was seen again by Dr. Van Pufflin in October of 1975 for symptoms in his low back, with numbness in his right leg and foot.  He received treatment for these symptoms for several months.

In February of 1981, the employee experienced increased low back pain following a motor vehicle accident, and on November 15, 1982, he underwent a bilateral hemilaminectomy L5-S1, with decompression of S1 nerve roots and a lumbro-sacral fusion.

In July of 1994, the employee sustained a work injury, which included a lumbar strain, while working as a pipefitter.  He subsequently worked light duty through approximately 1999, when he settled that workers’ compensation case.^[2]

The employee saw Dr. Joseph Henry in July of 1999 for right hip pain.  X-rays taken at the time revealed mild degenerative changes of the hips and SI joints.  An MRI of the pelvis showed no evidence of significant bony pathology or avascular necrosis in either hip.

When seen by Dr. Edward E. Martinson in November of 1999, the employee complained of increasing pain in his lower back and episodes of right hip locking.  He was referred to neurosurgeon Dr. Robert Donley, who, in December of 1999, advised the employee that surgical intervention was not warranted at that time.

The employee was seen by Dr. Kenneth Irons, his primary care physician, on March 24, 2000, complaining, in part, of right hip pain and lower back pain.  The employee indicated that he had made application for disability retirement to his pipefitters union.

On October 18, 2000, the employee returned to Dr. Martinson, complaining of ongoing lower back and right hip pain.  When he returned to Dr. Martinson in June of 2001, the employee reported that he had been approved for Social Security disability benefits.  Thereafter the employee operated an excavation business, primarily installing and repairing septic/sewer systems, working essentially full time during the summers from 2001 through 2004.

In November of 2001, x-rays of the employee’s hips and pelvis reflected moderate degenerative changes in the right hip as well as the left, but with more joint space narrowing on the right.  Dr. Henry recommended an inter-articular injection of the right hip, which was performed on November 13, 2001.  The employee had additional injections in 2002, without substantial relief, and, on December 9, 2002, he underwent a total right hip arthroplasty.

The employee was seen on August 1, 2006,^[3] by an orthopedic surgeon, Dr. Joseph Henry, following an intra-articular injection on July 6, 2006, for left hip pain of several months duration.  While x-rays of the employee’s pelvis revealed some mild medial arthrosis, Dr. Henry recommended no further treatment at that time, since the employee had experienced almost 90% relief of his left hip pain from the injection.^[4]

Orthopedist Dr. Janus Butcher examined the employee on August 7, 2007, at which time the employee was complaining of right hip pain radiating from the low back down to the knee.  The employee described this pain as similar to that which what he had experienced before his laminectomy.  Dr. Butcher diagnosed spinal stenosis and prescribed a Medrol Dosepak.

The employee underwent an MRI of the lumbar spine on August 15, 2007, followed by a steroid injection.  He returned to Dr. Butcher reporting some improvement from the Medrol Dosepak but no significant relief from the injection.

The employee was seen by neurosurgeon Dr. Robert Donley on September 20, 2007.  Dr. Donley diagnosed lumbar spondylosis with severe spinal stenosis at L3-4.  On November 14, 2007, the employee underwent decompressive laminectomies involving L3-5, medial L3-4 and L4-5 partial facetectomies, and decompression of the thecal sac.

The employee returned to Dr. Donley on January 3, 2008, complaining of right hip pain into the right buttocks.  While he had right heel numbness, that symptom had begun to improve after his back surgery.

On April 1, 2008, the employee began work for Lakehead Constructors, Inc. [the employer], as a boilermaker.  A few days later, on April 6, 2008, he slipped and fell at work, falling on his right shoulder and right hip/buttock.  He returned to work on April 7, 2008, but fell again, this time falling forward onto his forehead, nose, and right shoulder.

The employee first treated for these injuries on April 9, 2008, at the Duluth Clinic Urgent Care, and was referred to the emergency room at St. Mary’s Medical Center.  X-rays of the hips, lumbar spine, thoracic spine, and cervical spine revealed no fractures.

When seen by Dr. Irons on April 21, 2008, the employee complained in part of left leg pain, which had been present before his 2007 back surgery and had recurred.  The employee’s exam on that date revealed slight tenderness in the lumbar spine, with mild spasm.

The employee had physical therapy beginning on May 12, 2008, for right low back and buttock pain.  When seen in his primary care doctor’s office on May 20, 2008, the employee complained of stabbing pain in the left buttock with prolonged walking or sudden twisting or turning and occasional numbness in the left shin area.

A lumbar MRI was performed on June 3, 2008.  No change from the August 2007 MRI scan was noted except for a slightly worsened degenerative disc bulge at L4-5.  The employee again reported pain radiating down the left leg, with some anterior left leg numbness.

In the summer of 2008, the employee returned to self-employment in excavating.  In June or July, he slid down the embankment of an excavated hole.

The employee saw neurosurgeon Dr. Nancy Ensley on August 4, 2008.  His primary complaint at that time was of sharp pain in the left low back, which went into the buttock if he twisted or moved quickly.  Dr. Ensley found no indication for low back surgery at that time but stated that the employee had degenerative joint disease of the left hip, which, at some point, would likely require surgery.  She recommended that the employee follow up with an orthopedist and opined that the degenerative joint disease of the left hip was not related to his falls at work.

An independent medical examination was performed on August 26, 2008, by Dr. Tilok Ghose.  It was his opinion that the employee had sustained a contusion to his right hip on April 6, 2008, and a contusion to his nose on April 7, 2008.  He felt that the employee had reached maximum medical improvement [MMI] by April 21, 2008, without any residual effects from those falls.  The employer and insurer then filed a notice of intention to discontinue benefits, and benefits were discontinued effective September 22, 2008.  In response, the employee filed an objection to discontinuance.

On September 30, 2008, orthopedist Dr. Douglas Hoffman referred the employee for an intra-articular hip injection later that day.  On October 13, 2008, the employee reported to Dr. Hoffman that he had been 100% pain free for two days but that the pain had subsequently returned.  An MRI of the left hip performed on October 13, 2008, showed no collapse of the femoral head nor any definite fracture line.  The scan did, however, show some osteoarthritis and mild bone edema.

The employee underwent left L4-5 and L5 facet joint injections, administered by Dr. Seidelmann, on October 21, 2008.  Left-sided medial branch blocks and intralaminen epidural steroid injections at L3-4 were performed in November of 2008.

On November 26, 2008, the employee was examined at the Twin Cities Spine Center by Dr. Daryll Dykes, who also reviewed the lumbar MRIs from 2007, May of 2008, and October of 2008.  It was his opinion that the three MRIs showed no significant differences, and he recommended against additional surgery.

The employee returned to Dr. Hoffman on December 8, 2008.  According to his office notes, Dr. Hoffman had received a call from Dr. Ensley, informing him that it was her feeling that, while there was some pain coming from the employee’s lumbar spine, there was “a significant component from the hip.”  Dr. Hoffman referred the employee to orthopedic surgeon Dr. J. Joseph Davis.

On his return to Dr. Ensley on December 12, 2008, the employee had complaints of ongoing low back pain and a noticeable limp on the left.  Dr. Ensley recommended that the employee see Dr. Davis about a total left hip arthroplasty.

At Dr. Ensley’s suggestion, the employee was also evaluated by occupational medicine specialist Dr. Lynn Quenemoen.  Dr. Quenemoen saw the employee on December 26, 2008, and concluded that the employee had suffered a temporary aggravation of his preexisting low back condition as a result of his two falls.  Dr. Quenemoen left causation as to the left hip up to Dr. Davis, suggesting that a pathology specimen be taken in the event the employee underwent a total hip arthroplasty.

The employee underwent a left total arthroplasty, performed by Dr. Davis, on January 9, 2009.  Specimens taken on that date showed chronic/preexisting avascular necrosis, which had caused a reactive fracture/collapse.

In February of 2009, Dr. Davis wrote to the employee’s attorney, opining that the employee’s falls in April of 2008 had significantly aggravated the employee’s left hip condition and had contributed to the need for the left total hip arthroplasty.

On April 28, 2009, the employee returned to Dr. Davis, reporting overall hip pain resolution but continued pain in his low back, left of the SI joint.  Dr. Davis noted that he was hopeful that the employee’s low back discomfort would gradually resolve as the employee was walking in a more normal manner.  He released the employee to light-duty work.

On May 8, 2009, Dr. Ensley diagnosed the employee as having lumbar spondylosis and referred him for physical therapy.

Dr. Ghose’s deposition was taken on January 16, 2009.  At that deposition, Dr. Ghose opined that the employee’s left hip process and ultimate surgery were the result of a preexisting age-related degenerative arthritis, which had progressively worsened, and that the falls had not caused or aggravated that left hip condition.  He further testified that, at most, the employee could have sustained a low back contusion in his falls, which would have resolved within three weeks.

The objection to discontinuance proceeded to hearing, and, in findings and order filed on June 16, 2009, the compensation judge found that the employee’s low back condition had resolved without residuals by the date of Dr. Ghose’s examination; that the employee’s falls at work in April of 2008 did not temporarily or permanently affect, aggravate, or cause the employee’s left hip condition, that the employee had no residual effects from those falls; and that the employee was not entitled to reinstatement of weekly indemnity benefits.  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 (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 employee first contends that Dr. Ghose did not have adequate foundation for his opinions and that the compensation judge therefore erred in accepting those opinions.  We are not persuaded.

As acknowledged by the employee, Dr. Ghose, as a medical doctor who reviewed medical records and performed an examination of the employee, had adequate foundation to render opinions about the employee’s condition.^[5]  What the employee is really arguing is that Dr. Ghose’s opinions are not reliable because he

Dr. Ghose’s deposition was taken on January 16, 2009, one week following the employee’s left hip replacement.  The surgical report and pathology report were not available at that time.  Dr. Ghose testified that he did not examine the employee’s left hip on the date of his exam because the employee made no complaints of left hip pain.  Dr. Ghose based his testimony on his review of additional medical records and a lengthy hypothetical given to him by the employer and insurer’s attorney.  It was ultimately Dr. Ghose’s opinion that the employee’s two falls at work in April of 2008 did not cause or aggravate the employee’s left hip condition.  According to Dr. Ghose, if the falls had been a significant contributing cause of the employee’s left hip condition, the onset of symptoms would have been much closer in time to those falls.^[6]  Dr. Ghose was also of the opinion that a fall onto the right hip would not cause injury to the left hip.

The surgical and post-surgical pathology reports were reviewed by Dr. Davis for purposes of rendering his causation opinion of February 13, 2009.  While it was his opinion that the April 2008 falls had significantly aggravated the employee’s left hip condition, Dr. Davis admitted that the avascular necrosis of the left hip noted in the January 2009 pathology report clearly preexisted the collapse of the femoral head.^[7]  In addition, Dr. Davis apparently based his opinion in part on a description of the employee’s falls contained in a letter from the employee’s attorney.  In that letter, the attorney represented that, on April 7, 2008, the employee had slipped and “twisted his left hip to avoid falling on his right hip,” that neither fall had resulted in the employee striking his left hip, and that the employee had some pain in his left buttock later on the day after the April 7, 2008, injury but “not enough to tell his doctors about.”  However, the employee did not testify to these things at hearing.^[8]

Questions of medical causation fall within the province of the compensation judge.  Felton v. Anton Chevrolet, 513 N.W.2d 457, 50 W.C.D. 181 (Minn. 1994).  A judge’s choice between experts whose testimony conflicts is usually upheld unless the facts assumed by the expert in rendering his opinion are not supported by the evidence.  Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).

In the instant case, where Dr. Ghose had adequate foundation, that is, familiarity with the employee’s medical history and treatment following the falls in 2008, the compensation judge could properly rely on his opinions.  There is no suggestion anywhere in the record that any information contained in the surgical report or pathology report would have changed Dr. Ghose’s opinions, in that he relied primarily on the delay in onset of left hip symptoms as the basis for his opinions.

We would note, in addition, that the compensation judge did not rely solely upon the opinions of Dr. Ghose.  The judge also expressly accepted the opinion of “treating neurosurgeon Dr. Nancy Ensley,” to the effect that the employee’s left hip condition and treatment were unrelated to the falls in April, 2008.  As previously indicated, Dr. Ensley, a treating doctor, noted on August 4, 2008, that the employee had degenerative changes of the left hip which were “obviously not work related.”  The opinions of Dr. Ghose and Dr. Ensley provide substantial evidence to support the judge’s finding that the employee’s left hip condition was not related to his work injuries in April of 2008.

The employee contends that the compensation judge should have adopted the opinion of Dr. Ensley as to causation for the employee’s low back condition and that it was reversible error for the judge “to fail to discuss medical opinions submitted or to fail to address the employee’s theory of the case.”  The employee further contends that the compensation judge “ignored. . . the comprehensive evaluation and opinion expressed by Dr. Lynn Quenemoen.”  Again, we are not persuaded.

Dr. Ensley’s opinion is contained in the “plan” portion of her office note for August 4, 2008.  Specifically, she stated, “to rule-out any unexpected injuries from his two falls at work I would suggest a total body bone scan because of increased left low back and pelvic pain since the fall at work.  This is work related.”  In her December 12, 2008, office note, Dr. Ensley noted that she had reviewed prior x-rays, MRIs, and the bone scan and had “not been able to sort out anything there that needs definitive attention.”  She further noted that the employee was concerned “as to what is considered related to his workplace fall and what is not” and that she had explained to him that “generally we try to leave those decisions and opinions to a third party that is not involved in his treatment.”

On December 26, 2008, Dr. Quenemoen noted initially that “determining causation in this case is very difficult if not impossible.”  She went on, however, to state, “at the very least I think the work-related falls caused an aggravation of his back condition.  Whether this constitutes a temporary or permanent aggravation is not clear at this time since his left hip condition hasn’t been fully evaluated or treated yet.”

Contrary to the employee’s argument, a judge need not discuss every piece of evidence introduced at hearing.  Regan v. VOA Nat’l Housing, 61 W.C.D. 142 (W.C.C.A. 2000).  We also reject the employee’s contention that, “if Dr. Ensley was competent to express an opinion on the left hip condition . . . then the court certainly should have also adopted the opinion of Dr. Ensley regarding the low back condition.”  A compensation judge may accept part of an expert’s opinion while rejecting other parts.  See, e.g., Klasen v. American Linen, 52 W.C.D. 284 (W.C.C.A. 1994).  The employee’s contention that the compensation judge “ignored” the opinion of Dr. Quenemoen is also without basis.  The compensation judge made a specific finding that incorporated that doctor’s opinion.

Again, the judge’s decision regarding causation of the employee’s low back condition boils down to a choice between conflicting expert opinions.  The judge accepted the opinion of Dr. Ghose.  The employee has cited to no facts assumed by that expert that are not supported by the evidence.  Nord, 360 N.W.2d 337, 37 W.C.D. 364.

This was a complicated case.  The medical evidence was extensive.  The employee had a history of low back difficulties dating back to 1971, and, while Dr. Quenemoen’s opinion supported the employee’s contention that the falls in 2008 aggravated or accelerated his low back condition, there was also evidence to the contrary.  The issue on appeal is not whether the evidence will support an alternative finding but whether substantial evidence supports the findings made by the compensation judge.  Hengemuhle, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239.  Because Dr. Ghose’s opinion provides substantial evidence to support the judge’s findings regarding the employee’s low back condition, we affirm the judge’s decision on that issue.