The employer and insurer appeal the compensation judge’s findings that a two-level cervical fusion surgery was reasonable and necessary medical treatment and was causally related to the employee’s March 18, 2008, personal injury.  We affirm.

Sharon Wiehoff, the employee, slipped on the stairs at her home on February 27, 2008, and experienced an onset of neck pain.  Prior to that date, the employee had no symptoms, treatment, or limitation associated with her neck, arms, or hands.  Following this incident, the employee’s neck pain gradually improved and she continued with her usual job duties for Independent School District No. 15, the employer, which was insured for workers’ compensation liability by Indiana Insurance, the insurer.

On March 18, 2008, the employee shoveled heavy deep snow at work and lifted eight fifty-pound bags of salt.  She then worked inside breaking down lunch tables when she felt an immediate pain between her shoulder blades that caused her to drop to her knees.  The employee was asked by a co-worker whether she wanted an ambulance.  The employee said she could not afford an ambulance and continued with her work duties.  The employer and insurer admit the employee sustained a personal injury on March 18, 2008, in the nature of a temporary cervical strain.

The employee underwent a cervical MRI scan on April 22, 2008, which showed multi-level degenerative disc disease, a reversal of the cervical lordosis, severe disc space narrowing at C5-6 and C6-7, a small right posterolateral disc herniation at C5-6 with annular bulging contributing to mild central spinal canal stenosis and encroachment on a moderate to severely chronically narrowed right neural foraman and mild impingement of the right C6 nerve root.  On April 24, 2008, the employee gave Dr. Roman Smulka a history of her fall at home with treatment by Dr. Mark Schoemacher for muscle/neck strain.  The employee also gave a history of lifting fifty pound bags of salt at work and shoveling, with an onset of pain over her right shoulder blade.  The doctor diagnosed cervicalgia and prescribed pain medication.

On April 30, 2008, the employee saw Dr. David Kraker, an orthopedic surgeon, on referral from Dr. Smulka.  The employee stated her symptoms began on February 27 when she slipped on the stairs but stated the pain improved over the next few days.  The employee gave a history of her March 2008 incident at work with an onset of cervical spine pain and numbness into her fourth and fifth fingers.  The employee denied any radicular arm pain or weakness.  Dr. Kraker recommended an epidural steroid injection and physical therapy and instructed the employee to remain off work.

The employee received an epidural steroid injection and then commenced physical therapy.  In June 2008, the employee saw Dr. Philip Hoversten at the Allina Medical Clinic.  She reported neither the epidural injection nor the physical therapy improved her condition substantially and she continued to complain of neck and shoulder pain.  On examination, Tinel’s and Phalen’s signs were negative but cervical range of motion was limited.  Dr. Hoversten diagnosed chronic neck and shoulder pain and recommended an active rehabilitation program and restrictions at work.  A few weeks later, Dr. Margo Hutchinson at the same clinic noted the employee had increased cervical pain but found no radiculopathy with axial compression.  The doctor recommended continued physical therapy.

The employee saw Dr. Sherif Roushdy at Advanced Spine Associates in October 2008.  The doctor recorded a history of cervical pain with radiation into her right arm and her left shoulder.  The doctor’s diagnoses were cervical radiculopathy, cervical spondylosis, and multi-level degenerative disc disease.  Dr. Roushdy scheduled another epidural steroid injection, a facet joint nerve block and ablation, and continued physical therapy.

Dr. Richard Hadley examined the employee in November 2008 at the request of the employer and insurer.  The doctor stated his neurologic examination was normal but noted the employee had a non-anatomic sensory deficit that could not be explained by any anatomic abnormality of the cervical spine.  Dr. Hadley found mild limitation of motion of the cervical spine on examination and mild tenderness in the area of C7 with no palpable muscle spasm.  The doctor concluded the employee had multi-level degenerative disc disease which pre-existed her personal injury.  Dr. Hadley opined the employee sustained a cervical strain at home in February 2008 which was exacerbated by her work activities on March 17, 2008.  Dr. Hadley opined the employee reached maximum medical improvement [MMI] on November 18, 2008, and stated the employee was capable of working subject to restrictions.

The employee returned to see Dr. Kraker in February 2009 with continued complaints of neck pain radiating into her right arm and weakness in her right hand.  The doctor found decreased grip strength in the employee’s right hand and suspected a progressive right C6 radiculopathy.  Dr. Kraker recommended a cervical CT scan.  Dr. Roushdy performed a cervical epidural steroid injection several days later with only mild pain improvement.  Thereafter, the employee followed with Dr. Roushdy whose diagnosis remained cervical radiculopathy, cervical spondylosis and multi-level degenerative disc disease.

Dr. Hadley reexamined the employee in June 2009.  The employee complained of neck pain with radiation into her right shoulder, which was aggravated by activity.  On examination, the doctor noted demonstrated limitation of motion of the cervical spine and grip strength weakness on the right side.  Dr. Hadley noted that the employee had numerous abnormalities of her cervical spine, the most significant being foraminal stenosis between C5 and C6, which would be consistent with a C6 nerve radiculopathy.  The doctor’s diagnoses remained unchanged as did his opinion that the employee reached MMI as of November 18, 2008.  The doctor recommended, however, that the employee undergo a selective injection of the right C6 nerve root partly for diagnostic and partly for therapeutic reasons.

The employee continued to follow with Dr. Roushdy until May 2010 when she returned to see Dr. Kraker.  The doctor reviewed a March 2010 cervical CT scan which showed severe foraminal stenosis at C5-6 on the right with a paracentral disc herniation contributing to nerve root compression, moderate bilateral foraminal stenosis at C6-7 and severe disc degeneration with disc collapse at both C5-6 and C6-7.  On examination, the doctor found decreased right hand grip strength and diminished right biceps and triceps strength.  Dr. Kraker recommended an anterior cervical disectomy and fusion at C5-C7.  The doctor stated he did not believe the employee’s cervical radiculopathy would improve without surgery due to the severe stenosis present at C5-6.

On May 12, 2010, Dr. Charles Burton examined the employee at the request of the employer and insurer.  The doctor reported the employee was neurologically intact on examination and he concluded the employee had never demonstrated true radiculopathy.  His diagnosis was longstanding multi-level degenerative disc disease unassociated with evidence of objective neurologic impairment.  Dr. Burton opined this condition was aggravated by the employee’s injuries in February and March 2008 but he concluded the employee reached MMI from the effects of her March 2008 personal injury in November 2008.  The doctor stated Dr. Roushdy’s treatment was appropriate for the employee’s degenerative disc disease but opined the surgical recommendation of Dr. Kraker was unnecessary because the employee was neurologically intact and premature because the employee had not had an EMG of her upper extremities.

The employee continued to follow with Dr. Roushdy.  In July 2010, the doctor reviewed the employee’s March 2010 CT scan and opined she should proceed with an anterior cervical discectomy and fusion due to her cervical radiculopathy.

In August 2010, the employee saw Dr. Hart Garner, a neurosurgeon, for a second opinion.  On examination, the doctor found normal strength in the employee’s hand and arms with normal deep tendon reflexes.  The doctor reviewed the recent CT scan and the April 2008 MRI scan which, he concluded, demonstrated significant foraminal stenosis particularly at C5-6 on the right.  Dr. Garner went on to state,

In October 2010, the employee returned to see Dr. Roushdy with complaints of severe pain into her neck and both arms.  His diagnosis remained degenerative disc disease and chronic bilateral upper extremity pain consistent with radiculitis.  In November 2010, Dr. Roushdy noted the employee continued to have dysesthesias in both arms with normal strength and reflexes.  Follow up examinations by Dr. Roushdy in December 2010 and January 2011 were unchanged.

Dr. Burton reexamined the employee on January 17, 2011.  The employee then complained of pain in both shoulders and arms with spasms and a tendency to drop items.  The doctor again stated the employee had extensive multi-level degenerative disc disease unassociated with evidence of any neurologic impairment.  Dr. Burton concluded that radiculopathy had not been substantiated either by neurologic examination or by an EMG.  Dr. Burton opined there was no objective evidence to support the recommendation that the employee undergo a discectomy and fusion surgery.

The employee was seen by Dr. Matthew Hunt, a neurosurgeon, in January 2011.  The doctor concluded the employee’s symptoms were consistent with radiculopathy, especially at C6 and probably at C7.  An EMG study ordered by Dr. Hunt was essentially normal with no evidence of radiculopathy in either arm.  The employee returned to see Dr. Hunt in February 2011.  The doctor noted the employee’s EMG study did not demonstrate any sign of carpal tunnel syndrome and stated that he was “willing to proceed with a C5-7 anterior cervical discectomy and fusion once the patient has quit smoking.”  (Employee’s Ex. D.)

Dr. Burton issued a supplemental report in March 2011, after reviewing the EMG study.  The doctor stated the EMG examination documented no evidence for radiculopathy or plexopathy which, he concluded, confirmed that the employee had no objective evidence of radiculopathy.  Dr. Burton again stated opined the proposed discectomy and fusion was contra-indicated and opined the employee was a poor candidate for such a surgery.

The employee filed a claim petition seeking various benefits and approval for the two-level cervical fusion.  Prior to hearing, the parties resolved all of the issues except for the surgery.  Following a hearing, the compensation judge found the proposed two-level cervical fusion was reasonable and necessary to cure and relieve the employee from the effects of her March 18, 2008, personal injury and was causally related to that injury.  The employer and insurer appeal.

The appellants contend the compensation judge’s finding that the two-level cervical fusion surgery proposed by Dr. Kraker is reasonable and necessary is unsupported by substantial evidence.  They argue that although Dr. Roushdy and Dr. Kraker recommended a fusion surgery, neither of them had the benefit of the February 2011 EMG study prior to rendering their opinions.  Dr. Hunt did consider the EMG in rendering his opinion that a fusion surgery was appropriate treatment but the appellants contend he did not explain why the surgery was appropriate given the negative EMG test.  Further, they argue Dr. Hunt did not review the employee’s medical history prior to rendering his opinions.  The appellants contend the opinions of Drs. Roushdy, Kraker, and Hunt are factually unsupported and lack foundation.

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.  Drews v. Kohl’s, 55 W.C.D. 33 (W.C.C.A. 1996) (citing Reinhardt v. Colton, 337 N.W.2d 88, 93 (Minn. 1983)), summarily aff’d (Minn. July 11, 1996).  There is no dispute as to the scientific expertise of either Dr. Roushdy or Dr. Kraker or that they both examined the employee on multiple occasions.  Dr. Hunt examined the employee and his report reviewed in some detail the employee’s past medical history.  As a general rule, this level of knowledge is sufficient to afford foundation for the opinions of medical experts.  See, e.g., Caizzo v. McDonald’s, 65 W.C.D. 378 (W.C.C.A. 2005).  Dr. Hunt concluded the employee’s symptoms were consistent with radiculopathy, but ordered an EMG of both arms to rule out carpal tunnel syndrome.  The EMG showed no evidence for carpal tunnel syndrome so the doctor stated he was willing to proceed with a C5-C7 anterior cervical discectomy and fusion.  Clearly, Dr. Hunt did not conclude the negative EMG negated the necessity for surgery.  While the doctor did not fully explain his reasoning, any such failure goes to the weight to be afforded the opinion, not its admissibility.  See Goss v. Ford Motor Co., 55 W.C.D. 316 (W.C.C.A. 1996), summarily aff’d (Minn. Oct. 17, 1996).  We conclude Drs. Roushdy, Kraker, and Hunt all had foundation for their opinions and the compensation judge could properly rely upon them.

The appellants also assert there is insufficient evidence in the nature of objective test findings and consistent clinical findings to support a conclusion that the employee has radiculopathy.  In support of this argument, the appellants cite to medical records which document that at various times the employee has had full range of motion in her hands and shoulders, full upper extremity strength, no radiculopathy with axial compression of the neck and no motor/sensory impairments of the arms.  The appellants also contend the normal EMG study establishes the employee has no radiculopathy.  Accordingly, the appellants ask this court to reverse the compensation judge’s finding that the proposed surgery is reasonable and necessary.

There is some merit to the appellants’ argument.  We note, however, there are physical therapy notes referencing positive Spurling nerve root compression tests and clinical notes documenting decreased grip strength in the right hand, a positive Spurling sign with evidence of a radicular component into the right arm at the C5 to C7 distribution, positive evidence of facet loading at C4-C7, and diminished right biceps and triceps strength.  The cervical MRI scans reflect significant degenerative disc disease and a bulging disc at C5-6 causing significant forminal stenosis particularly evident at C5-6 on the right.  Dr. Hunt examined the employee in January 2011 and opined that her symptoms seemed consistent with a C6 radiculopathy.  There is, therefore, evidence in the medical records supporting the compensation judge’s decision.  Further, as the compensation judge correctly noted, a surgical recommendation is not based exclusively on objective testing.  A doctor’s professional judgment is also a significant factor in any decision to perform surgery and the compensation judge may rely on the doctor’s opinion.  On balance, we cannot conclude the decision of the compensation judge was clearly erroneous or unsupported by substantial evidence.  We affirm the compensation judge’s finding that the proposed surgery was reasonable and necessary medical treatment.

Finally, the appellants assert the judge’s finding that the employee’s personal injury caused the need for the proposed surgery is unsupported by substantial evidence.  Only Dr. Burton, the appellants argue, provided a properly founded causation opinion and he concluded the fusion surgery was not causally related to the employee’s work injury.  Accordingly, the appellants assert the compensation judge’s decision awarding the fusion surgery should be reversed.  We disagree.

Questions of medical causation fall within the province of the compensation judge.  Felton v. Anton Chevrolet, 513 N.W.2d 457, 459, 50 W.C.D. 181, 184 (Minn. 1994).  A work injury is compensable if the employment is a substantial contributing factor not only to the cause of the condition but also to the aggravation or acceleration of a pre-existing condition.  Wallace v. Hanson Silo Co., 305 Minn. 395, 235 N.W.2d 363, 28 W.C.D. 79 (1975).  An employee need not prove that the employment was the sole cause, only a substantial contributing cause of the disability for which benefits are sought.  See Swanson v. Medtronics, Inc., 443 N.W.2d 534, 536, 42 W.C.D. 91, 94-95 (Minn. 1989).

Dr. Hart Garner opined the employee’s personal injury was a substantial contributing factor to her need for surgery.  The appellants, however, contend his opinion lacked adequate factual foundation because his report contained no reference to the employee’s February 2008 fall at home and because he did not review the employee’s medical records.  Dr. Garner did, however, obtain a history from the employee that she had no significant problems with her arms and neck prior to her March 2008 personal injury.  This history is consistent with the judge’s unappealed finding that the employee’s neck pain gradually improved following the February 2008 incident and she was able to work thereafter without restrictions.  Further, there is no medical evidence reflecting the employee sought treatment for neck pain until her March 2008 personal injury.  That Dr. Garner was apparently unaware of the February 2008 incident may go to the weight to be afforded his opinion but does not impact its admissibility.  The compensation judge could reasonably rely upon the opinion of Dr. Garner in concluding the proposed fusion surgery was causally related to the employee’s personal injury.  Since that decision is supported by substantial evidence, it must be affirmed.  See Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).