The employee appeals from the compensation judge’s finding that the employee failed to establish that his personal injury of July 18, 2005, was a substantial contributing factor in the need for proposed lumbar spine surgery.  We affirm.

James Kroells [the employee] began working for Cemstone, Inc. [the employer], as a cement truck driver in about 1987.  Prior to the injury here at issue, he had a long history of back complaints, most of them related to his cervical and thoracic spine but some occasional ones related to his low back and legs.  While the latter complaints were not of severe pain, medical records do reflect significant pre-existing degenerative changes in the lumbar spine.

On July 13, 2005, the employee saw Dr. Albert Salazar at the Fairview Cedar Ridge Clinic, complaining that his back had begun to hurt several days earlier without any triggering incident.  On examination, Dr. Salazar noted that the employee appeared to be in mild to moderate pain and had an antalgic gait, although on examination the lumbosacral area revealed no local tenderness or mass.  The doctor did note painful and reduced lumbosacral range of motion, but there were no radiating lower extremity symptoms, and deep tendon reflexes, motor strength, and sensation were normal, including heel and toe gait.  The doctor diagnosed a lumbar strain, prescribed medication, recommended rest and cold packs along with analgesics and muscle relaxants, and instructed the employee to “call or return to clinic prn if these symptoms worsen or fail to improve as anticipated.”

Five days later, on July 18, 2005, the employee sustained an admitted work-related injury to his low back as a result of a fall from his cement truck.  He was climbing the metal ladder on the back of the truck when a rung snapped and he fell backwards about four or five feet to the ground, landing on his buttock and hip.  The employee contacted Dr. Salazar’s clinic about a week later, on July 25, 2005, for a refill of the medication that had been prescribed for him on July 13.  No clinic notes were prepared on July 25, 2005, and it does not appear that the employee actually saw Dr. Salazar.^[]

The employee was examined by Dr. Salazar for the first time following his July 18, 2005, work injury on August 22, 2005.  On that date, the employee provided a history of having injured his low back “several months ago.”  As he had noted on July 13, 2005, Dr. Salazar recorded that the mechanism of injury was unknown, and his findings on examination were essentially the same as those he had made on July 13, 2005.  X-rays of the lumbar spine revealed no fracture or dislocation but did reveal “arthritis of the back.”  Dr. Salazar’s assessment was “lumbar strain and possible herniated disc at L4-5 S1.”

On August 24, 2005, the employee called Dr. Salazar’s office, reporting that he was still having extreme back pain and that it was getting worse each day, and an MRI scan of the lumbar spine was ordered.  The MRI, performed on August 25, 2005, was interpreted as showing severe central stenosis at the L4-5 level secondary to degenerative spondylolisthesis and a thickened ligamentum flavum.  In addition, at L5-S1 there was moderate to severe bilateral L5 foraminal stenosis, greater on the right than on the left, due to loss of disk height and lateral endplate spurring.  Four days later, on August 29, 2005, the employee awoke with severe back pain.  He called the clinic and was taken off work, and a referral to a spine specialist was ordered.

Dr. Salazar’s office notes make reference to a work injury for the first time on September 12, 2005.  On that date, the employee telephoned the doctor’s office to report that he was still waiting for a reply to an inquiry into possible workers’ compensation coverage for his injury.  Dr. Salazar’s nurse prepared a note for the doctor, indicating that “[the employee] feels work comp will not validate claim since saw you in clinic for back pain before injury occurred. [W]ondering if there is anything you can do to validate that claim is valid.”

On September 22, 2005, Dr. Salazar mailed a letter to the employee addressed “Dear Sirs,” in which he stated in part the following:

The employee was seen in consultation by orthopedist Dr. John Sherman on October 10, 2005.  In the history provided to Dr. Sherman, the employee described the fall from his truck on July 18, 2005, and indicated that, one week prior to that incident, “he was experiencing some upper back pain which was diagnosed as a muscle strain.”  The employee explained that he had been using analgesics and muscle relaxants following his muscle strain and that, when he discontinued this pain medication, he noted significant low back pain in addition to bilateral thigh pain, greater on the right than on the left.  He also indicated that he had noted a burning sensation in the right great toe at the time.  After examining the employee and reviewing his MRI scan, Dr. Sherman concluded that the employee’s symptoms were most likely due to his spinal stenosis and that his work activities were a substantial contributing factor in his need for treatment.  On those conclusions, Dr. Sherman recommended a lumbar epidural steroid injection.

The epidural steroid injection apparently only helped for one day, and the employee returned to see Dr. Sherman on December 1, 2005.  Dr. Sherman again related the employee’s condition to his work activities, “given his history that he lacked significant low back pain complaints and/or neurogenic claudication prior to his fall at work.”  Treatment options were discussed, and Dr. Sherman recommended lumbar decompression surgery.

At the request of the employer and insurer, the employee was examined by orthopedic surgeon Dr. Richard Hadley on January 11, 2006.  In his report dated January 12, 2006, Dr. Hadley diagnosed severe central stenosis at the L4-5 level, together with foraminal stenosis at the L5-S1 level.  He concluded that the employee’s scoliosis, central stenosis, and degenerative spondylolisthesis noted on imaging studies predated the injury of July 18, 2005, and were not caused by that event, and he did not believe that the medical records documented any objective change in the employee’s condition since the work incident.  In support of this conclusion, Dr. Hadley noted that “Dr. Salazar’s physical examination as recorded in the available records appears to be identical between July 13, 2005, and August 22, 2005.”  He found the employee’s past treatment and proposed surgical decompression to have been and to be reasonable and necessary but unrelated to the claimed injury.  He attributed no work restrictions or permanent partial disability to the injury of July 18, 2005.

On February 21, 2006, the employee filed a claim petition seeking approval for the surgery recommended by Dr. Sherman.

In a letter dated April 26, 2006, Dr. Salazar reiterated the employee’s history of the fall from the truck on July 18, 2005, and his complaint of back pain continuing since that event.  He concluded that “it does seem that the pain [the employee] is experiencing is indeed the result of this accident and the treatment to date has been reasonable.”

The employee’s claim for approval of the proposed low back surgery came on for hearing before a compensation judge on June 6, 2006.  The sole issue presented to the judge was whether the employee’s work injury of July 18, 2005, was a substantial contributing factor in the need for that surgery.  At the hearing, the employee testified that he “overdid it” the weekend prior to July 13, 2005, and that he thought he had pulled a muscle in his mid-back.  He stated further that his pain was located just below his shoulder blade and that it was aggravated by coughing or movement.  He specifically denied any low back symptoms, and he disputed the accuracy of Dr. Salazar’s July 13, 2005, office note, explaining that he had subsequently discussed the content of the note with Dr. Salazar.

In a findings and order issued June 14, 2006, the compensation judge found that the employee had not shown that the July 18, 2005, specific injury was a substantial contributing factor in the need for the proposed lumbar surgery.  The judge therefore denied payment for the proposed surgery.  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 (2004).  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 the 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 contends that no evidence, including the opinions contained in Dr. Hadley’s report, supports the judge’s findings and order.  He argues that the judge found the employee to be “generally credible” and that the fact that the employee sustained an injury to his low back on July 18, 2005, is undisputed.  He contends that at no time prior to this date did any physician recommend low back surgery or record complaints consistent with a need for low back surgery.  Further, he argues, because Dr. Salazar recorded an inaccurate history and subsequently corrected the record, and because Dr. Hadley did not reference or explain away these repeated corrections, the judge’s findings are unsupported by the record.  We are not persuaded.

In a memorandum accompanying his findings and order, the compensation judge explained that there were two main reasons why he was unable to conclude that the July 18, 2005, injury was a substantial contributing factor in the employee’s need for lumbar surgery.  The judge stated,

It is well settled that the employee has the burden of proving that any claimed medical expenses were 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).  Contrary to the employee’s assertion, Dr. Salazar did not acknowledge that he recorded an inaccurate history.  Nor do the records support the employee’s assertion that his symptoms were substantially different on August 22, 2005, from what they were on July 13, 2005.  While the employee’s low back symptoms quite clearly worsened after his work injury, the records do not clearly support the conclusion that that worsening was due to the work injury.  “Where two opposing inferences can be drawn with equal justification from the same circumstantial evidence, it cannot be said that one preponderates over the other, and in that event the party having the burden of proof must lose.  If different inferences can justifiably be drawn from the evidence in the case, the inference drawn by the factfinder will not be disturbed on appeal.”  Dille v. Knox Lumber/Div. of Southwest Forest, 452 N.W.2d 679, 681, 42 W.C.D. 819, 823 (Minn. 1990).

While the employee did submit medical and factual evidence in support of his claim for low back surgery causally related to his fall on July 18, 2005, the compensation judge was not required to accept entirely either the employee’s testimony as to his symptoms or his interpretation of the medical records.  The judge’s analysis of the evidence, particularly of the medical records, is entirely reasonable and supported by the record as a whole.  As the judge explained in his memorandum, Dr. Salazar’s letters subsequent to his office notes on July 13, 2005, do not dispel the discrepancy between those office notes and the employee’s testimony as to his symptoms on that date.  Nor do the records support the employee’s testimony that his symptoms were entirely different after the work injury and before his next visit to Dr. Salazar on August 22, 2005.  While the judge could reasonably have reached a different conclusion based on the evidence, the conclusion that the judge did reach is supported by the record.  Accordingly, the judge’s determination that the employee has not shown that his July 18, 2005, specific injury was a substantial contributing factor in his need for the proposed lumbar surgery is affirmed.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.

The employee also contends that the opinions contained in the independent medical report of Dr. Hadley are not supported by adequate foundation and should not have been afforded evidentiary value.  Specifically, the employee contends that Dr. Hadley referenced only Dr. Salazar’s erroneous history and not his subsequent corrections to the record.  We are unpersuaded by this argument also.  The competency of a medical expert to provide an expert opinion depends upon both the extent of the scientific knowledge of the expert and the expert’s practical experience with the matter that is the subject of the expert opinion.  Reinhardt v. Colton, 337 N.W.2d 88 (Minn. 1983).  Dr. Hadley is an orthopedic surgeon, and he examined the employee on January 11, 2006.  On that occasion, he obtained a history from the employee, reviewed the relevant medical records, and performed a physical examination.  As a general rule, this level of knowledge is sufficient to afford foundation for the opinion of a medical expert.  See, e.g., Caizzo v. McDonald’s, 65 W.C.D. 378 (W.C.C.A. 2005).  The fact that Dr. Hadley did not specifically reference Dr. Salazar’s September 2005 statements that the employee’s symptoms at that time were different from those described on July 13, 2005, does not render Dr. Hadley’s opinions without foundation.

In the present case, the judge’s decision appears to have been based primarily upon the judge’s conclusion that the employee had not met his burden of proving that his work injury was a substantial contributing factor in his need for surgery even aside from Dr. Hadley’s expert opinion.  To the extent, however, that the judge may have relied on Dr. Hadley’s opinions in reaching his conclusion, we conclude that Dr. Hadley’s opinions were adequately founded and provide substantial evidence to support the judge’s decision.  We therefore affirm the judge’s decision in its entirety.