The employer appeals the compensation judge’s findings that the proposed low back decompression and fusion surgery was reasonable, necessary, and causally related to the employee’s February 2013 work injury.  We affirm.

On February 7, 2013, Denise Bantz, the employee, was involved in a motor vehicle accident while working for H.O.M.E.S., Inc., the employer, which was self-insured for workers’ compensation liability.  The employee sought treatment the next day at Fairview Mesaba Clinic for her cervical and lumbar spine, left shoulder, right hip, and right elbow.  She was treated with medication and physical therapy.  Her low back pain worsened and she began experiencing right leg pain and right foot numbness.  An April 17, 2013, lumbar spine CT scan indicated spondylolytic spondylolisthesis of L5 on S2 and neural foraminal narrowing at L5-S1.  On April 29, 2013, the employee was treated with an epidural injection.

The employee was referred to a neurosurgeon, and was evaluated by Dr. Dionysios Klironomos from St. Luke’s Neurosurgery Associates on May 20, 2013.  Dr. Klironomos ordered cervical and lumbar MRI scans.  A June 14, 2013, lumbar spine MRI indicated L5-S1 spondylolisthesis with associated osteophytes, a broad-based disk protrusion with partial annular tear at L5-S1 with L5 nerve root compression, and a small central disk protrusion at L4-5.  The employee was able to continue working, but with a 20 pound lifting restriction. 

In July 2013, Dr. Klironomos diagnosed L5-S1 spondylolisthesis and right L5 nerve compression, and recommended posterior lumbar interbody fusion surgery.  He noted that in a January 27, 2014, report that the L5-S1 spondylolisthesis was likely developmental and “it is possible that [the employee] aggravated a pre-existing condition with respect to that injury.  However, it is not possible to know for certain.”  (Employee’s Ex. 3.)  He recommended L5-S1 decompression and fusion surgery.  In a February 19, 2014, deposition, the employee testified that she had ongoing right leg pain and right foot numbness.  Dr. Klironomos stated in a March 20, 2014, report that the employee’s MRI indicated “an asymmetric broad-based disk protrusion with compression of the right L5 nerve root in the foramen at L5-S1 on the right,” which “could have been accelerated by the motor vehicle collision.”  He also relied on the fact that her right leg symptoms began after the accident to conclude that “it is highly probable that the motor vehicle collision on [February 7, 2013,] accelerated the necessity for the need for decompression and lumbar fusion surgery for [the employee].”

The employee had a previous work-related low back injury on July 29, 2009, and was diagnosed with cervical strain with headaches and lumbar strain with right-sided sciatica.  She was treated with medication and physical therapy from September 25 through October 16, 2009.  The employee did not lose any time from work for the 2009 injury.  After physical therapy was completed, the employee did not note any improvement and reported that she had increased right leg pain along the lateral thigh and ankle.  A cervical spine MRI scan was unremarkable.  The employee later testified that her headaches stopped after treatment with medication.  There are no medical records indicating any low back or right leg treatment from late October 2009 until after the 2013 work injury.

On September 16, 2013, the employee was examined by Dr. Nolan Segal at the employer’s request.  Dr. Segal diagnosed multi-level degenerative disc disease with developmental lytic spondylolisthesis at L5-S1 which was unrelated to her 2013 work injury.  He stated that the spondylolisthesis was a pre-existing condition which was not aggravated by the work injury.  He opined that the employee did not need any further treatment relative to her work injury and that her need for surgery was not related to the work injury and should only be done if she stopped smoking.  The employee has smoked cigarettes for 27 years.  Dr. Klironomos did not comment on the employee’s smoking history or the need for her to stop smoking before the surgery.

In November 2013, the employee filed a claim petition for approval and payment of the proposed low back fusion surgery and for attorney fees.  The employer denied the claim.  In January 2014, Dr. Nolan issued a supplemental report summarizing medical journal articles on studies showing that smoking has adverse effects on spinal fusion surgery, including an increase in pseudoarthrosis, inhibition of fusion, and a decreased success rate.  (Employer’s Ex. 2.)  Dr. Nolan issued another report on April 14, 2014, after reviewing additional medical records.  He concluded that the employee’s February 7, 2014, work injury was not a substantial contributing factor of the employee’s current leg symptoms due to her developmental condition and her previous history of right lumbar radicular symptoms in 2009.

After a hearing on April 22, 2014, the compensation judge found that the employee’s February 2013 work injury was a substantial aggravating and contributing cause of the employee’s current low back and right leg symptoms and her need for surgery.  He also found that the decompression and fusion surgery was reasonable and necessary.  In his memorandum, the compensation judge noted that the employee should stop smoking before the surgery, but that failure to do so should not preclude the employee from necessary medical care.  The self-insured employer 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.  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 compensation judge relied on Dr. Klironomos’ opinion and specifically found Dr. Segal’s opinion unpersuasive.  A judge’s choice between expert opinions is generally upheld unless the facts relied upon 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).  The employer argues that Dr. Klironomos’ opinion lacks foundation, claiming that he relied on incorrect information that the employee’s symptoms improved after physical therapy in 2009 and that she did not have right leg symptoms between October 2009 and the 2013 injury.  Based on this information, the employer argues that Dr. Klironomos erroneously assumed that the employee had recovered from this condition.

The employer is correct that the employee’s physical therapy records do not indicate that the employee’s right leg symptoms had improved as of October 16, 2009, and that the employee was reporting right leg pain down to her ankle at that time.  However, there are no further medical records of treatment for any of the employee’s conditions until after the 2013 work injury.  The employee testified that these symptoms did not continue throughout that time, that she did not seek further treatment, and that her work activities were not affected.  (T. 35-36.)  Dr. Klironomos had adequate foundation for his opinion and could reasonably conclude that the employee’s current right leg symptoms had started after the 2013 work injury and that the injury accelerated the employee’s need for surgery.  We find no foundational deficiency in his expert opinion, and we conclude that the judge was entitled to rely upon this opinion.

The employer also argues that since Dr. Klironomos’ opinion is based on the employee’s ongoing right leg symptoms after the 2013 injury and because the employee testified at the hearing that she was not currently having right leg symptoms, the compensation judge erred by finding that the employee “now has pain down her right leg.”  (Finding 2.)  We disagree.  When asked at the hearing if she had right leg symptoms that day, the employee responded that she did not.  But she also testified that she still experiences the symptoms, just not all the time.  (T. 46.)  In the February 2014 deposition, the employee testified that she had ongoing right leg pain and right foot numbness.  The compensation judge could infer that the employee had ongoing right leg symptoms in making his causation determination.  Substantial evidence supports the judge’s finding that the employee’s 2013 work injury is a substantial contributing cause of the employee’s current low back and right leg symptoms and her need for surgery, and we affirm.

The employer also argues that the surgery is not reasonable and necessary because the employee’s smoking habits significantly decrease the likelihood that the spinal fusion surgery will be successful.  The compensation judge found that fusion surgery can be successful even in a patient who smokes.  The employer argues that this conclusion is not supported by any evidence in the record, and cites Dr. Segal’s opinion and medical articles which indicate that smoking decreases the likelihood of a successful fusion surgery.  The employer further cites the employee’s testimony at the hearing that she did not have a current plan to quit smoking.  The employee, however, testified that if the recommended surgery “were approved, I would definitely quit.”  (T. 71.)  The judge noted that smoking only increases the odds for a failed fusion, as Dr. Segal and the medical articles indicated.  The judge could reasonably infer that a successful fusion was possible for a patient who smokes or could have credited the employee’s testimony of her intent to quit smoking.  Substantial evidence supports the compensation judge’s finding that the proposed fusion surgery is reasonable and necessary, and we affirm.