The self-insured employer appeals from the compensation judge’s determination that the employee’s injury on March 13, 2009, represented a permanent aggravation of his preexisting condition that has precipitated his need for surgery.  The employee cross-appeals from the compensation judge’s determination that the employee is not entitled to a rehabilitation consultation.  We affirm the compensation judge’s findings and order, with the exception of the finding related to the rehabilitation consultation, which we reverse.

Chad A. Woodford, the employee, began working in November 2005 for Xcel Energy, the self-insured employer.  The claim at issue on appeal relates to an injury the employee sustained on March 13, 2009, while working as a yard equipment operator.  On that date, the employee attempted to lift a garbage can, and experienced severe low back pain.  He consulted his family physician, Dr. Elaine Hirschfield, with whom he had previously treated for his low back; she restricted him from work and he has remained off work since then.  The employee eventually was diagnosed with left-sided sciatica with neural foraminal spinal stenosis as well as degenerative disc disease at the L5-S1 and L4-5 levels.  He has undergone medical treatment which, by now, has included orthopedic treatment and a recommendation for a two-level decompression and instrumented spinal fusion.

The employee reported his injury to his supervisor the same day he was injured, initially referring both to the lifting incident and to an earlier low back injury.^[1]  The employer denied primary liability for the claimed 2009 injury, contending that the employee’s condition was related to his significant pre-existing back condition for which he was awaiting surgery, and also contending that the employee had provided inconsistent reports of the origin of his low back pain.  In April 2009, the employee filed a claim petition, seeking payment of temporary total disability benefits, payment of medical expenses, and provision of rehabilitation assistance, including a rehabilitation consultation.

The employee initially injured his low back in December of 2005, as the result of an automobile pedestrian accident that occurred while he was assisting a driver whose car was in a ditch.  While he was standing and attempting to attach a tow rope to the disabled car, the employee was hit by another car.  He was examined at the North Memorial Medical Center emergency department where he was diagnosed with lumbar strain and left knee contusion.  The employee consulted Dr. Elaine Hirschfield for follow-up treatment, primarily reporting left knee pain but also advising of aching in his low back; she diagnosed lumbar strain and left knee contusion, with no evidence for internal derangement in his knee.

Dr. Hirschfield restricted the employee from work until late December 2005, at which time he returned to work on a light-duty basis, performing janitorial duties for one to two months.  He eventually returned to his regular job duties and obtained follow-up treatment for his left knee from Dr. Hirschfield.  By February 2006, the employee consulted Dr. Paul Crowe for an orthopedic evaluation of his knee.  Dr. Crowe concluded that the employee’s left knee was stable and referred him to a physical therapist for patellofemoral exercise.

By July 2006, the employee again consulted Dr. Crowe, reporting both left leg and low back pain.  He had by then undergone chiropractic treatments for his low back symptoms, with no improvement.^[2]  Dr. Crowe’s orthopedic examination and testing revealed positive results, and an MRI scan conducted in June 2006 revealed a broad-based central and left paracentral disk herniation at the L5-S1 level with mass effect on the traversing left S1 nerve.  Dr. Crowe provided the employee with an epidural steroid injection, which provided no pain relief.

By August 2006, Dr. Crowe advised the employee that he probably needed a surgical decompression or disc excision; the employee declined surgery, and Dr. Crowe instead prescribed a regimen of tapered Prednisone.  That medication provided no relief, and Dr. Crowe ultimately performed surgery in April 2007, in the nature of laminotomy and excision of a herniated disc on the left side of the L5-S1 vertebral level.

By October 2007, due to his continued low back pain, Dr. Crowe referred the employee to Medical Advanced Pain Specialists, where he underwent an assessment for potential participation in a chronic pain rehabilitation program, and also received a medial branch block for diagnostic purposes.  By January 2008, the employee sought emergency room treatment, due to an exacerbation of his low back pain resulting from bouncing on large equipment at work.  He also consulted Dr. Hirschfield, reporting low back pain extending into his left thigh.  A follow-up MRI scan showed a recurrent left paracentral disk protrusion at the L5-S1 level, but no progression of the disk degeneration at the L4-5 level.  The employee returned to Dr. Crowe in February 2008, reporting worsened pain in the past two months and a flare-up of low back and left leg pain after moving heavy equipment at work.  Dr. Crowe provided the employee with an epidural steroid injection for treatment of his symptoms.

It appears that the option of surgery was discussed by the employee and Dr. Crowe in early 2008, although the record does not specify the type of surgery under consideration.  In February 2008, Dr. Crowe noted that the employee was “not interested in having surgery at this point.  In about a year and a half he would like it taken care of.”  The employee testified that he was working as a temporary employee at that point, and was concerned that if he left his job for any reason at any time before the temporary position expired, he would lose that job.  By mid-March 2008, Dr. Crowe noted that the employee felt no benefit from the Prednisone prescribed earlier, and that the employee would call ahead several weeks when he was finally able to schedule surgery, but that “it could be a year.”

The employee did not consult Dr. Crowe any further in 2008 but instead continued to consult Dr. Hirschfield periodically, and continued to use pain medication.  In November 2008, he reported ongoing symptoms in his left thigh and a burning pain on both sides of his spine.  Dr. Hirschfield’s chart notes in November 2008 reflect that the employee planned to have a “redo surgery on his back when he can take the time off from work.”  She referred the employee to the Minneapolis Clinic of Neurology for further advice on his radicular symptoms, although the record contains no medical records from that clinic.

The employee next consulted Dr. Hirschfield on the injury date at issue, March 13, 2009, reporting severe low back pain and left leg pain which started at work after he bent down to try to lift a garbage container.  Dr. Hirschfield diagnosed an acute exacerbation of the employee’s disc degeneration.  She restricted him from work until he underwent a surgical evaluation; her chart note states that she urged the employee to “pursue his surgery sooner than fall 2009.”

Dr. Crowe, who had last seen the employee a year earlier, examined the employee on March 19 and diagnosed an acute lumbar strain from his lifting injury.  Dr. Crowe initially expected a “complete resolution” of the employee’s lumbar strain, prescribed Flexeril, and informed the employee that he would refer him for an MRI scan if his condition did not improve after one week.  By early April, however, the employee’s symptoms had progressively worsened.  An MRI scan conducted on April 7, 2009, was interpreted to show a small left paracentral disc herniation decreased in size from the January 2008 MRI scan, no evidence of new disc herniation at L5-S1 level, and a disc protrusion at the L4-5 level, associated with an annular tear, slightly increased from the January 2008 MRI, with mild secondary central canal stenosis.

Dr. Crowe advised the employee that he had two levels of significant disc degeneration, and that if he “had anything done it would probably be a two level fusion.”  Dr. Crowe attempted conservative treatment, including a left L5-S1 transforaminal epidural steroid injection, which provided only temporary relief.  Following a lumbar discogram in late April, Dr. Crowe again concluded that the employee was a candidate for a two-level fusion.

On August 24, 2009, at the request of the self-insured employer, Dr. Mark Friedland examined the employee.  At that time, the employee reported constant low back pain and pain, weakness and intermittent numbness in his left leg and thigh.  Dr. Friedland concluded that the employee’s pedestrian accident in December 2005 caused a significant injury to the L4-5 and L5-S1 discs.  He found no substantial change between the findings of the MRI scans conducted in 2008 and 2009, and therefore felt that any minimal changes would be consistent with a natural progression of degenerative disc disease.  Dr. Friedland acknowledged that Dr. Crowe did not specify, in his 2008 clinical notes, the type of surgical procedure he anticipated for the employee, but that:

Dr. Crowe also addressed the issue of causation.  In his opinion, the employee’s previous herniated disc and the degenerative condition resulting from his earlier surgery were permanently aggravated by work injuries he had sustained.  Dr. Crowe referred to one injury as “perhaps February 7, 2008, when he was working heavy equipment,” and to the injury on March 13, 2009, which, in his opinion, was a substantial contributing factor to the employee’s current disability and need for medical treatment.  Dr. Crowe concluded that surgery would be reasonable and necessary based on the attempts at conservative treatment and the employee’s discogram pain studies.

The employee’s claim petition was addressed at hearing on September 25, 2009.  The parties stipulated that the surgery proposed by Dr. Crowe would be reasonable and necessary for the employee’s back condition, although causation for that condition remained in dispute.  In her findings and order issued following that hearing, the compensation judge found that the employee’s injury on March 13, 2009, represented a permanent aggravation of his post-surgically repaired herniated disc at the L5-S1 level.  She relied on Dr. Crowe’s opinion in reaching her conclusions, finding his opinion on the issue of causation to be accurate and well-reasoned.  The compensation judge also found that, as a result of his lifting injury on March 13, 2009, “the employee needs a two-level decompression and instrumented spinal fusion at the L4-5 and L5-S1 levels, as proposed by Dr. Crowe,” and that the March 13, 2009 injury represented a substantial contributing factor in the need for surgical repair.  The compensation judge awarded payment of temporary total disability benefits since March 16, 2009.  She concluded that Dr. Crowe has not yet released the employee to return to work and that the employee credibly testified about his severe leg and back pain that both limits his activities and movements and must be controlled through the use of pain medication.

As to the employee’s request for a rehabilitation consultation, the compensation judge denied that request.  The compensation judge concluded that the employee was not a qualified employee since, at the present time, no treating doctor had advised when the employee could be reasonably expected to return to work within restrictions and therefore it was premature to assume the employee will be unable to return to work for the employer.

The employer appeals from the compensation judge’s findings that the employee’s March 13, 2009, injury was a permanent aggravation of his preexisting condition and from the award of temporary total disability and payment of medical expenses.  The employee cross-appeals from the compensation judge’s determination that the employee is not entitled to a rehabilitation consultation.

The compensation judge relied on Dr. Crowe’s opinion that the employee’s March 2009 injury substantially contributed to his low back condition and his need for additional surgery.  The employer appeals, arguing that Dr. Crowe lacked the foundation to render such an opinion, and therefore the compensation judge had no basis to rely on that opinion when rendering her decision.  The employer specifically contends that Dr. Crowe did not explain, in his report of August 17, 2009, how the March 2009 work injury permanently aggravated the employee’s underlying condition; why his initial diagnosis of a lumbar strain later changed to a diagnosis of spinal stenosis and degenerative disc disease; what objective evidence supported his opinion; and whether the employee’s symptomatic flare-up in February 2008, to which Dr. Crowe referred, also represented a permanent aggravation of the employee’s underlying condition.

To be of evidentiary value, an expert medical opinion must be based on adequate foundation.  Welton v. Fireside Foster Inn, 426 N.W.2d 883, 41 W.C.D. 109 (Minn. 1988); Bode v. River Valley Truck Ctr., No. WC09-132 (W.C.C.A. Sept. 29, 2009).  The competence of a witness to render expert medical testimony depends upon both the degree of the witness’s scientific knowledge and the extent of the witness’s practical experience with the matter at issue.  Reinhardt v. Colton, 337 N.W.2d 88 (Minn. 1983).  Our review of Dr. Crowe’s records shows that he examined the employee on numerous occasions between 2006 and 2009, originally in 2006 following his motor vehicle accident.  Over the course of his treatment of the employee, Dr. Crowe conducted physical examinations of the employee, obtained histories from him, reviewed the employee’s films from his x-rays and MRI scans of his lumbar spine, reviewed results from diagnostic testing, recommended conservative medical treatment, including epidural injections, and conducted surgery on his lumbar spine in April 2007.  As a general rule, this level of knowledge establishes a doctor’s competence to render an expert opinion.  See Grunst v. Immanuel-St. Joseph’s Hosp., 424 N.W.2d 66, 40 W.C.D. 1130 (Minn. 1988).  Dr. Crowe had adequate foundation for his medical opinion.

As to the employer’s argument that Dr. Crowe’s opinion was deficient because he did not explain the basis for his causation opinion, an expert medical opinion does not lack foundation because the doctor fails to explain the mechanism of injury or the underlying reasons for his opinion.  Rather, the presence or absence of such testimony goes to the weight that may be afforded the opinion by the compensation judge.  All that is required, under the facts of the case when considered as a whole, is that a competent medical witness opined that the injury causally contributed to the disabling condition.  See, e.g., Goss v. Ford Motor Co., 55 W.C.D. 316 (W.C.C.A. 1996); Darnick v. Swett & Crawford, slip op. (W.C.C.A. Oct. 29, 2002).  Here, Dr. Crowe clearly expressed his opinion that the 2009 lifting incident caused injury to the employee’s lumbar spine resulting in a need for surgical treatment.  His opinion was adequately founded, and the compensation judge could reasonably rely on that opinion.

The employer also argues that the compensation judge did not address the discrepancy between the employee’s testimony and that of the supervisor to whom the employee reported his injury, and that the judge never explained whether she was accepting the testimony of the employee or supervisor.  We disagree with that characterization.  In her memorandum, the compensation judge referred to the testimony of both witnesses, and specifically cited to their individual descriptions of the employee’s duties as an equipment operator and to their respective testimony concerning the employee’s report of his 2009 injury.  The judge acknowledged that the employee and supervisor have differing recollections about the employee’s report and later telephone calls, but they both agree “there was discussion of a lifting incident and there was a discussion of the employee’s pre-existing condition.”  The compensation judge explained that the “characterization by the manager and the employee as to whether or not this is a new injury or attributable to the pre-existing injury is not the determining factor in deciding causation.”

We agree with that conclusion by the judge.  Questions of causation fall within the province of the compensation judge, and the witnesses’ assessments of causation are not determinative.  See Felton v. Anton Chevrolet, 513 N.W.2d 457, 50 W.C.D. 181 (Minn. 1994).  In addition, where the record contains conflicting medical opinions, as here, concerning the employee’s diagnosis and need for surgery and on the issue of causation, it is the compensation judge's responsibility, as trier of fact, to resolve conflicts in expert testimony.  Nord v. City of Cook, 360 N.W.2d 337, 342, 37 W.C.D. 364, 372 (Minn. 1985).  As we have often held, this court will generally affirm a compensation judge’s decision which is based on a choice between competing medical opinions.  Perry v. ADB Constr., Inc., 68 W.C.D. 491 (W.C.C.A. 2008).

It is evident from the findings and order that the compensation judge reviewed the medical opinions and records, as well as the witnesses’ testimony, when determining the issues before her.   The judge concluded that there was a causal relationship between the employee’s 2009 work injury and his current low back condition and need for surgery.  Factors that the compensation judge considered when reaching her conclusions included the nature of the employee’s equipment operator job; his ability to perform that job when first hired by the employer in 2005 and after he recovered from his pedestrian accident in December 2005; the symptom flare-up that the employee experienced in February 2008 and the ongoing chronic pain that the employee experienced in 2008 and early 2009; and the onset of more severe low back symptoms that the employee reported on March 13, 2009.  The compensation judge also outlined the medical expert opinions provided by both Drs. Crowe and Friedland, and adopted Dr. Crowe’s opinion as she considered it to be accurate and well-reasoned.

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).  Substantial evidence, including expert medical opinions, supports the compensation judge’s findings that as a result of his March 13, 2009, injury, the employee sustained an injury to his lumbar spine, and that there is a causal connection between the employee’s injury and his current condition and need for the recommended surgery.  Accordingly, we affirm those findings.

The employee’s request for rehabilitation services was also at issue at the hearing.  The compensation judge found that the employee’s request for a rehabilitation consultation was premature.  In her memorandum, the compensation judge explained that the employee was not a qualified employee for rehabilitation services, as defined by the Minnesota Rules, “since there is no treating doctor’s opinion of his work ability indicating when the employee can be reasonably expected to return to work within specified restrictions, as defined by Minn. R. 5220.0100, subp. 22C.”^[4]  (Memo., p. 7.)  The compensation judge also concluded that it was premature to assume the employee would be unable to return to work for the employer, and, because there was no evidence of the same, the employee “is not a qualified employee at this time.”  Id.  The employee appeals, arguing that the compensation judge erred as a matter of law when determining that the employee was not entitled to a rehabilitation consultation.  We agree.

According to Minn. Stat. § 176.102, subd. 4(a), “a rehabilitation consultation must be provided by the employer to an injured employee upon request of the employee, the employer, or the Commissioner. . . .  If a rehabilitation consultation is requested, the employer shall provide a qualified rehabilitation consultant.”  In this case, the employee requested a rehabilitation consultation in his claim petition served on April 6, 2009, and in his amendment to the claim petition served on June 2, 2009.  The purpose of a rehabilitation consultation is to determine whether the employee is qualified to receive statutory rehabilitation services.  The Minnesota Rules require that an employee must be determined to be a qualified employee for rehabilitation services before a rehabilitation plan can be implemented.  Minn. R. 5220.0100, subp. 22, and Minn. R. 5220.0130, subp. 1.

An employee is entitled to a rehabilitation consultation as a matter of right, unless the employer or insurer has filed a timely request for a waiver of the same.  Schierman v. Diversified Printers, slip op. (W.C.C.A. Jan 13, 1998); Minn. R. 5220.0110, subp. 7.A.  Whether an employee is a “qualified employee” as referred to in the statute, “is not a threshold issue in determining whether an employee is entitled to a rehabilitation consultation.”  Wagner v. Bethesda Hosp., slip op. at 3 (W.C.C.A. Jan. 5, 1995).  The purpose of the rehabilitation consultation is to determine that issue, and therefore, in the absence of timely filing a waiver, for which there is provision in the rules, an employee is entitled to a consultation.  “Once a rehabilitation consultation has been held, an employer and insurer have the right to challenge the determination made by the rehabilitation consultant, pursuant to Minn. R. 5220.0950, but cannot, in effect, forestall the determination of the rehabilitation consultant” of whether the employee is a qualified employee.  Id.

In this case, there is no dispute that the employee requested rehabilitation services, specifically a rehabilitation consultation, in his claim petition and amended claim petition.  Under the statute and the rules, the employee is entitled to a rehabilitation consultation.  We therefore reverse the compensation judge’s denial of the same, and order the provision of a rehabilitation consultation to the employee.