The self-insured employer appeals from the compensation judge's conclusion that the medical treatment at issue was causally related to the employee’s work injury.  We affirm.

On February 12, 1996, Frank Cruz, Jr., sustained an injury to his mid and low back when he slipped on some ice and fell onto his back in the course of his work as a meter reader with the City of St. Paul.  The City of St. Paul [the employer] was self-insured against workers’ compensation liability at the time of the injury, and Mr. Cruz [the employee] was twenty-four years old and earning a weekly wage of $425.20.

The employee’s history of medical treatment for his mid and low back condition is extensive and complex since the date of his February 1996 work injury, including as it does consultation with and examination by no fewer than sixteen different physicians.  On February 16, 1996, he saw Dr. Norman Westhoff, to whom he reported that the onset of symptoms after his slip and fall four days earlier had been gradual but that those symptoms were now present all of the time and included shooting pain into his right leg.  Upon examination, Dr. Westhoff concluded that the employee’s symptoms were work-related, diagnosed a lumbar strain, prescribed home icing, Motrin, and physical therapy, and released the employee to return without restrictions to his job with the employer.

On March 1, 1996, the employee apparently slipped again on ice in the course of his work with the employer, this time landing on his right arm and ribs.  He saw Dr. Westhoff again on that date, complaining of “pain all across the low back” but now complaining also that he thought that he had broken some ribs.  Dr. Westhoff diagnosed a dorsal strain and rib contusion, restricted the employee from working for one day, prescribed medications, and anticipated that the employee would reach maximum medical improvement [MMI] by March 8, 1996.  Four days later, on March 5, 1996, the employee saw Dr. Julia Halberg, requesting a change in medication.  Dr. Halberg reviewed the employee’s x-rays and, noting in part “a marked compression fracture of the T8 vertebral body of undetermined age,” imposed work restrictions and ordered a bone scan.  The employee returned to Dr. Halberg the following day, complaining of having been awakened suddenly the night before by a sharp pain and popping sensation in his right rib cage.  X-rays revealed a questionable fracture now more prominent at T9, and Dr. Halberg restricted the employee from all work and ordered the bone scan to be full body.  According to a report of Dr. Westhoff the following day, the scan revealed a pathologic and nonwork-related rib fracture.

On March 11, 1996, the employee underwent a CT scan of both his chest and his abdomen and pelvis.  The scan was read to reveal multiple lesions of the skeleton, which the reading radiologist thought “might represent a process such as multiple enchondromatosis, multiple neural fibroma,”^[1] or malignancy.  Due evidently to the rib fracture and not to the work-related rib contusion, which Dr. Westhoff termed “not disabling,” the employee remained subject to work restrictions until about May 11, 1996, when he was released to return to work unrestricted.  Pelvic and lumbar x-rays on May 13, 1996, revealed bone lesions that were reported not to have changed since films taken in March of 1989 and therefore to be “most likely . . . benign and likely related to some form of dysplastic bone such as fibrous dysplasia.”  By a Health Care Provider Report dated October 12, 1996, Dr. Halberg indicated that the employee had reached MMI with regard to his 1996 work injuries on May 13, 1996, with 0% permanent partial disability.

On January 17, 1997, nearly a year after his February 1996 injury, the employee sustained a second work-related injury to his mid and lower back, when he again slipped on some ice in the course of his work for the employer, apparently avoiding falling but wrenching his back.  Subsequent to this injury, on January 23, 2997, the employee saw Dr. Halberg again, who diagnosed a thoracic strain, which, assuming the employee’s history to be correct, she concluded to be work related. She released the employee to return to work subject to restrictions, prescribing medications and physical therapy.  The employee’s symptoms increased, and on February 11, 1997, he commenced treatment with Dr. John Harapat.  Eventual lower lumbar and pelvic x-rays on February 25, 1997, were reported on March 5, 1997, to “likely represent fibrous dysplasia,” and on March 7, 1997, Dr. Harapat released the employee to return to his job half time until March 12, 1997.  On the latter date, the doctor concluded, the employee could resume full-time work, would be at MMI with respect to his work injury, and would have no further need for treatment.

On July 11, 1997, the employee saw his family physician, Dr. T. Elumba, regarding continuing low back pain, and Dr. Elumba referred him to orthopedic surgeon Dr. Arnulf Svendsen at Summit Orthopedics.  Dr. Svendsen saw the employee on August 25, 1997, and recommended an MRI scan of the employee’s lumbar spine and pelvis.  The scan was conducted on September 2, 1997, and was read to reveal a suspected pathologic compression fracture at L5 and multiple osseous lesions in the right femur, pelvis, sacrum, and lower three vertebrae, which the radiologist concluded would be consistent with the employee’s history of “eosinophilic granulomas.”  On September 5, 1997, Dr. Svendsen opined that the employee was “going to require permanent restriction of his activities due to the pain caused by the injury of January 1997.”  Dr. Svendsen confirmed this opinion on September 12, 1997, in a letter to the employer, in which he stated as follows:

On October 1, 1997, in a letter to Dr. Svendsen, neurologist Dr. Kenneth Hoj concurred that, upon examination of the employee, he believed that the employee’s low back pain was related to the employee’s January 17, 1997, fall and work, which “most likely resulted in a compression fracture at L5.”  He indicated that he was “going to see about obtaining results of a previous biopsy to see if this is an eosinophilic granuloma” and “what role this may be playing with it though I think [the employee’s] major concern is the fall as a cause of the process.”

In a treatment note for October 24, 1997, Dr. Svendsen indicated that the employee had been doing primarily sedentary and limited light work, and he reiterated that the employee’s low back symptoms “were secondary to the fall in January of 1997.”  With the employee’s low back still continuing on December 19, 1997, Dr. Svendsen referred the employee first to Dr. John Dowdle and eventually to another of his colleagues at Summit Orthopedics, Dr. Jonathan Biebl, who saw the employee on March 31, 1998, and recommended a CT myelogram.  The scan was conducted on April 9, 1998, and was read to reveal multiple osseous lesions in the pelvis and low back unchanged since the September 2, 1997, MRI scan.  On April 14, 1998, Dr. Biebl ordered a whole-body bone scan, which was conducted on April 27, 1998, and was read to reveal lesion findings similar to those seen on earlier scans but “[n]othing to suggest a pathologic fracture.”

On April 30, 1998, the employee was examined for the employer by orthopedic surgeon Dr. Michael Davis.  After reviewing various medical records and radiological reports, Dr. Davis concluded, in a report to the employer’s claims adjuster, that the employee did sustain a lumbosacral strain at work on February 12, 1996, which might have been associated with a pathological compression fracture through a preexisting lesion at L5.  He explained that he did not believe, however, that the possible fracture at L5 was of any great significance or that the strain itself was related to the employee’s fracture at T8, “which is a typical ‘vertebral plana’ seen in eosinophilic granuloma,” here dating from the employee’s childhood or early adolescence.  It was Dr.  Davis’s opinion that the employee’s fractures had essentially healed and that none of his residual discomfort was due to his work-related injuries.  It was his opinion also that a “Park Aide” job that was being offered to the employee was physically inappropriate for the employee, “[c]onsidering [the employee’s] multiple bony lesions,” but he believed the employee capable of other full-time work, not entailing repetitive bending, twisting, and lifting of more than twenty-five pounds.  Dr. Davis concluded also that the employee had reached MMI with respect to his work injuries of February 12, 1996, and March 1, 1996.  Shortly thereafter, on May 18, 1998, the employee was examined also at the office of Dr. Jim Phillips at the Twin Cities Spine Center, who noted that radiographs had revealed “the possibility of a prior fracture at the distal aspect of L4, L5 and compression of the S1,” which was “probably made simpler by the presence of his multiple skeletal lesions.”

On June 1, 1998, evidently in response to several queries from the employer’s claims adjuster, Dr. Davis indicated that a compression fracture of a lumbar vertebral body with the mild deformity evident on the employee’s September 2, 1997, MRI scan would be rated as a 4% permanent partial disability of the body as a whole, pursuant to Minnesota Rules 5223.0390, subpart 2A(2).  Dr. Davis emphasized that the employee’s multiple spinal bone lesions due to his eosinophilic granuloma were present prior to the employee’s work injury and that they “very definitely predisposed [the employee] to the fractures which he sustained.  More than likely, had he not had the pre-existing bone lesions, it would have been a less significant injury or possibly no injury at all.”  Dr. Davis went on to state, however, that he did not believe that the injuries themselves had resulted in any permanent aggravation of the pre-existing eosinophilic granuloma condition.

On July 6, 1998, the employee saw spine surgeon Dr. Francis Denis at the Twin Cities Spine Center, who recommended anterior and posterior fusion, opining that the need for it was “the result in great part of his work accident of January of 1997 in spite of the pre-existing condition of fibrous dysplasia.”  The employee did not pursue the recommended of surgery.  On October 6, 1998, noting that the employee was complaining of weakness and numbness in his left leg from the anterior thigh, Dr. Biebl ordered an EMG of the employee’s left lower extremity and peroneal and tibial nerves.  On October 14, 1998, the employee saw occupational health specialist Dr. Vijay Eyunni, who diagnosed chronic degenerative disc disease of the lumbar spine and released him to work restricted from heavy lifting and repetitive bending, twisting, and turning.  The ordered EMG, conducted on October 16, 1998, was read to be essentially normal, and on October 20, 1998, Dr. Eyunni revised his diagnosis to chronic lumbosacral strain and released the employee again to restricted work.

The employee’s back spasm and radiating pain continued into the spring of 1999, and on April 21, 1999, Dr. Biebl recommended that the employee return to see Dr. Denis for reconsideration of surgery.  Dr. Denis evidently reiterated his recommendation, but, according to a note of Dr. Biebl on September 7, 1999, the recommendation became tied up legally.  About a year later, on August 1, 2000, with the employee continuing to complain of leg pain down his left thigh and his leg bothering him “all the time,” Dr. Biebl recommended that the employee “needs to have the surgery done” and that he return to see Dr. Denis for that purpose.  The employee’s low back pain continued into the following year, and on January 23, 2001, the employee complained to Dr. Edward McEllistrem of a flare-up that radiated into his buttocks.  Dr. McEllistrem diagnosed a low back strain superimposed on an underlying disc disorder “characterized by instability and eosinophilic granulomas” and apparently referred the employee back to Dr. Denis, who examined the employee on March 26, 2001.  Noting that the employee “continues to have significant low back pain with left leg pain,” Dr. Denis found the employee to be fairly normal on motor testing, except for some evidence of abnormality with straight leg raising tests on the left, and he and the employee discussed further the possibility of surgery.

On January 22, 2002, the employee underwent an MRI of the lumbar spine, which was read to reveal multiple osteolytic lesions within L3, L5, and the right and left iliac bones, and the radiologist recommended further evaluation for malignancy.  On February 20, 2002, upon order from Dr. Biebl, the employee underwent another lumbar MRI scan, which was read to reveal “multiple bone lesions; some larger, some smaller and some new when compared to previous study,” all “consistent with eosinophilic granulomas.”  The scan was read also to reveal increasing right neural foraminal stenosis at L5-S1 due to those bone lesions.  On March 12, 2002, Dr. Biebl concluded that the scan had revealed “expansive lesion of the posterior elements of L5 now” but “no essential granuloma,” although there did appear to be “some foraminal stenosis on the right that [the employee] did not have previously.”  On May 23, 2002, the employee returned to see Dr. Denis, who noted that the employee “continues to have severe back pain with leg pain.”  Dr. Denis’s first impression, pending review of the employee’s recent MRI scans, was that the employee required “a fusion in the area of his burst fracture of L5, superimposed on his hyperdysplasia,” or perhaps just a decompression alone.  Dr. Denis examined the employee again on September 16, 2002, when he noted that the employee “continues to be symptomatic in his lower back and leg,” particularly on the left side but also on the right.  Dr. Denis recommended continued anti-inflammatory medications and work restrictions.

By December 12, 2003, Dr. Biebl was still diagnosing chronic low back pain, noting active bilateral radicular pain in the employee as nothing new.  On June 16, 2004, the employee filed a claim petition, alleging entitlement to payment of $2,335.63 in medical expenses for treatment received from three providers since March of 2001 and to compensation for a permanent partial disability to 4% of his whole body consequent to his work injury on January 17, 1997.  In its answer on July 6, 2004, the employer denied payment on grounds that the work injury was only a temporary aggravation of an underlying and preexisting condition and that the medical care at issue was “due to a condition which is unrelated to the Employee’s work injury of January 17, 1997"–“a congenital condition identified as multiple osseous lesions [that] are a consequence of the Employee’s underlying non-work related disease process of eosinophilic granulomas.”  The employee continued to treat with Dr. Biebl at Summit Orthopedics through January 26, 2004.

On August 17, 2004, the employee saw Dr. Johanna Toninato with renewed severe back pain, which was now sharp and shooting down his right leg.  Dr. Toninato noted at the start of her treatment note that the employee “[s]ays he has had pain on and off since eight years ago when he had a work related injury,” that “[h]e also has some cysts on his vertebrae and on other bones,” and that “there is an ongoing battle of whether this is work comp or not.”  With that the doctor diagnosed “[o]ld work related injury with ongoing pain, now with exacerbation,” recommended continued exercises and work restrictions, and renewed the employee’s medication prescription.  On September 21, 2004, the employee underwent a whole-body bone scan that was read to reveal findings similar to earlier scans, “although there is more intense increased uptake over the region of the right SI joint, sacrum, and right maxilla.”

On November 2, 2004, the employee was examined for the employer by orthopedic surgeon Dr. John Sherman.  Upon taking a history from the employee, reviewing his medical records, and physically examining him, Dr. Sherman concluded in part that “[i]t is a possibility that [the employee’s] multiple Eosinophilic granuloma, which is present in multiple bony locations, is partially responsible for [the employee’s] ongoing symptoms.”  Dr. Sherman concluded that, “[b]ased on [the employee’s] history, it is unlikely that he sustained a fracture with the slip back in January of 1997,” in that, “[i]f he, in fact, had sustained a fracture at the time of the slip in January 1997, he acutely would have had marked severe pain in his low back.”  “It is more likely than not that his compression deformity is due to the pre-existing condition of histiocystosis-X and not due to any injury.”  Dr. Sherman opined also that the employee “would have reached [MMI] following the lumbar strain in January 1997 within 3-4 months following the slip.  The subsequent treatment that he has had rendered is due to the pre-existing diagnosis of histiocystosis and not due to any injury in January of 1997.”  Dr. Sherman opined in summary in part,

On July 18, 2005, Dr. Sherman testified by deposition, in part reiterating the conclusions and opinions that he had voiced in his report of November 2, 2004.  Specifically, he testified that he did not think that the anterior/posterior fusion surgery from L4 to S1 that had been proposed by Dr. Denis was warranted, that the employee was not subject to any permanent impairment related to his 1997 work injury, and that any pain as well as any pathology that was currently present in the employee’s low back was due to his underlying histiocytosis-X condition.  He testified that the employee would have reached MMI with regard to his January 16, 1997, work injury as early as March 12, 1997, and that the employee’s MRI scan conducted pursuant to treatment at the Twin Cities Spine Center in 2002 and physical therapy he underwent in 2003 and 2004 were related to his histiocytosis-X condition and not to his January 27, 1997, work injury.  Dr. Sherman testified further that, had the employee sustained a compression fracture on the latter date, he would have presented immediately with acute pain.  He testified also that, although the treatment in dispute was not causally related to the work injury, it was nevertheless reasonable as treatment for the preexisting condition.  Dr. Sherman did agree with Dr. Davis, that the employee’s preexisting histiocytosis-X condition can predispose a person to more ready fractures upon trauma.

The matter came on for hearing on July 21, 2005.  Issues at hearing included the following:  (1) whether, pursuant to Minnesota Rules 5223.0390, subpart 2A(2), the employee had sustained a work-related permanent partial disability to 4% of his whole body consequent to either his February 1996 work injury or his January 1997 work injury and (2) whether the employee’s treatment with Drs. Toninato and Chlebeck at the East Metro Family Practice in August and November of 2004, the employee’s treatment with Dr. Denis at the Twin Cities Spine Center in March 2001 and May and September 2002, the employee’s MRI scan at St. Paul Radiology on February 20, 2002, and the employee’s consultations with Drs. Biebl and Svendsen at Summit Orthopedics from August 1997 through January 2004 were all reasonable, necessary, and causally related to either of those work-related injuries.  At the hearing, the parties stipulated in part that the employee had sustained a work-related injury to his low back on January 17, 1997.  By findings and order filed September 15, 2005, the compensation judge concluded in part that the employee had failed to prove that either of his work injuries was a substantial contributing factor in any permanent partial disability to his low back.  The judge also concluded, however, that the medical treatment and diagnostic procedure at issue were nevertheless “reasonable, necessary, and causally related to the employee’s work-related injury of January 17, 1997,” and that the four intervening providers were therefore entitled to reimbursement from the employer.  The employer appeals.

In reviewing cases 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 (1992).  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, “[f]actfindings are clearly erroneous only if the reviewing court on the entire evidence is left with a definite and firm conviction that a mistake has been committed.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).  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 the evidence or not reasonably supported by the evidence as a whole.”  Id.

The compensation judge found that the employee had failed to prove that either of his work injuries was a substantial contributing factor in any permanent partial disability to his low or mid back, but she nevertheless awarded payment of $2,532.86 to four providers for medical services provided to the employee between August 25, 1997, and November 14, 2004.  In her memorandum, the judge discusses separately the expenditures at issue to each of the four providers, concluding in each case that the employee’s work-related injury in January of 1997 was a substantial contributing factor in the employee’s need for the treatment.  The employer contends that the judge’s award of the medical benefits at issue was both unsupported by substantial evidence, in light of the judge’s unappealed finding that the employee’s low back compression fracture was due to a preexisting bone disease, and legally inconsistent with her denial of permanent partial disability benefits.  This is a close issue, and had we been the judge we might well have decided it differently, but we cannot say that the judge’s decision was unreasonable.

The treatment here at issue with Dr. Denis at the Twin Cities Spine Center on three occasions in 2001 and 2002 was each time noted by the doctor as being pursuant to continuing symptoms in the low back and left leg.  In that Dr. Denis’s original assessment on July 6, 1998, had been that the employee’s need for the surgery that he was recommending was “the result in great part of [the employee’s] work accident of January of 1997 in spite of the pre-existing condition of fibrous dysplasia,” it was not unreasonable for the compensation judge to conclude that the employee’s January 1997 work injury was a substantial contributing factor in Dr. Denis’s continuing consultation.  Moreover, the MRI scan at St. Paul Radiology on February 20, 2002, that is here at issue^[2] was conducted at the request of Dr. Biebl, who remained supportive of Dr. Denis’s recommendation of surgery.  For that reason it was also not unreasonable that the compensation judge found the need for that MRI scan reasonable and necessary and causally related to the January 17, 1997, work injury.  Upon seeing the employee at the East Metro Family Practice on August 17 and November 14, 2004, respectively, both Dr. Toninato and Dr. Chlebeck specifically acknowledged the employee’s intermittent pain since his work injury eight years earlier, neither of them suggesting that that injury was not causally related to the employee’s symptoms, although Dr. Toninato did note that there was “an ongoing battle” over that issue.  Again, in light of these facts, we cannot conclude that it was unreasonable for the compensation judge to conclude that the employee’s work injury was a substantial contributing factor compelling the consultations at issue at East Metro Family Practice.

Finally, it was also not unreasonable for the compensation judge to conclude that the employee’s 1997 work injury was a substantial contributing factor in his need for treatment by Drs. Biebl and Svendsen at Summit Orthopedics between August 25, 1997, and January 26, 2004.  Early in that period, Dr. Svendsen concluded unequivocally, in his treatment note of September 5, 1997,  that the employee would require permanent restrictions “due to the pain caused by the injury of January 1997,” confirming that opinion in a letter to the employer on September 12, 1997, in which he opined that “the symptoms of the low back pain from January of 1997 appear to be related to a work-related fall” and that “[t]he non-work-related problem of eosinophilic granuloma may or may not play a part in the [employee’s] chronic low back pain.”  The treatment of Dr. Biebl, Dr. Svendsen’s colleague at Summit Orthopedics, began in consultation for and continued pursuant to the treatment of Dr. Svendsen and indeed supported the surgical recommendation of Dr. Denis, who also saw the employee’s condition as causally related to his work injury.  Under these facts, and notwithstanding the fact that Dr. Biebl may not appear himself to make as express a causal connection as do the other doctors between the work injury and the employee’s low back condition, we cannot conclude that it was unreasonable for the compensation judge to find that the employee’s treatment with Drs. Svendsen and Biebl at Summit Orthopedics was reasonable and necessary and causally related to the employee’s January 1997 work injury.

Because it was not unreasonable in light of the whole record in this case, we cannot find substantial evidence to reverse the compensation judge’s award of reimbursement to the four intervening providers in this case, notwithstanding the opinion of Dr. Sherman to the contrary.  See Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985) (a trier of fact'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); see also Tuomela v. Reserve Mining Co., 299 Minn. 203, 204, 216 N.W.2d 638, 639, 27 W.C.D. 312, 313 (1974) (although, under Flansburg v. Giza, 284 Minn. 199, 201-02, 169 N.W.2d 744, 746, 25 W.C.D. 3, 6 (1969), unopposed expert medical testimony cannot be disregarded, such testimony is not necessarily conclusive upon the trier of fact).  Nor do we find the judge’s award legally inconsistent with her conclusion that the employee did not prove entitlement to compensation for permanent partial disability pursuant to Minnesota Rule 5223.0390, subpart 2A(2).  That rule provides for compensation consequent to a compression fracture, and, while evidently attributing the employee’s fracture to his preexisting condition, the judge could reasonably have viewed a substantially contributing portion of the employee’s accompanying symptoms as continuing consequences of the January 1997 work injury, consistent with the opinions of Drs. Svendsen, Denis, and Biebl.  See Johnson v. L. S. Black Constr. Co., slip op. (W.C.C.A. Aug. 18, 1994) (a compensation judge is free to accept a portion of an expert's opinion, yet reject other portions of that expert's opinion), citing City of Minnetonka v. Carlson, 298 N.W.2d 763, 767 (Minn. 1980) (a factfinder generally "may accept all or only part of any witness' testimony").  Therefore we affirm the judge’s award of the medical benefits here at issue.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.