The employee appeals the compensation judge’s findings and order denying; (1) medical care related to the spinal cord stimulator; (2) temporary total disability benefits; and (3) permanent partial disability benefits.  The self-insured employer cross-appeals the compensation judge’s finding that the employee was entitled to temporary partial disability benefits.  We affirm in part and vacate in part.

On August 6, 2008, David J. Mach sustained a work-related injury to his right leg while working as a crane operator for Wells Concrete Products Co., the employer, which was self-insured for workers’ compensation liability.  The employee was assisting other workers when he was hit in the left thigh by an auger attachment to a skid steer.  The employee was hospitalized at the Albany Area Hospital and Medical Center and treated by Dr. Heather Swanson for swelling and abrasion on the left thigh.  An x-ray of the left thigh indicated no fracture.  The employee was discharged on August 8, 2008, with instructions to follow up with physical therapy.  The employee returned to Dr. Swanson on August 11, reporting that his leg had turned cold and purple.  Dr. Swenson noted on examination that the employee’s left leg was cool to the touch with a bluish-purple color.  An MRI was read as normal and the radiologist suggested that a sympathetic abnormality was possible.

On September 17, 2008, the employee reported increased leg pain to Dr. Swanson, who diagnosed likely sympathetic dystrophy, recommended an orthopedic evaluation, and referred the employee for physical therapy.  After moving to northeast Minnesota, the employee attended physical therapy at the Iron Range Rehabilitation Center and was evaluated by Dr. T. Scott Douglas at the Duluth Clinic-Virginia Medical Center on September 29, 2008.  Dr. Douglas diagnosed a contusion and crush injury to the left leg, patellofemoral tendonitis, sacropelvic dysfunction, slight decrease in temperature of his left lower leg and foot, but no other physical findings suggesting reflex sympathetic dystrophy (RSD) such as swelling, mottling, or loss of range of motion at that time.

The employee continued to seek treatment with Dr. Douglas for increasing pain in his left knee in October and November 2008.  On December 4, 2008, the employee underwent an MRI of the left knee, which indicated no evidence of a meniscal tear, cruciate, or collateral ligament injury, possible mild patellar tendonitis, and small subchondral cyst, and a synovial cyst.  Based on this MRI, Dr. Douglas referred the employee to an orthopedic specialist.  On December 16, 2008, the employee treated at the Duluth Clinic Urgent Care, reporting that his left foot had turned purple on three occasions, tingling in his left leg, and a sharp stabbing pain in his left thigh.  The physician’s assistant who examined the employee noted that the employee’s left foot was cooler than the right and had markedly different coloration compared to his right foot, and assessed likely complex regional pain syndrome (CRPS).  The employee was treated with medication and again referred to an orthopedic specialist.  The employee was seen at Orthopedic Associates on December 17, 2008, but no treatment was advised.

On December 19, 2008, the employee was evaluated by Dr. Brian Konawalchuk from the Duluth Clinic occupational medicine department.  Dr. Konowalchuk noted that on examination the employee’s left foot was purple compared to the right foot which resolved when both feet were extended, that there was a several centimeter depression consistent with the impact site, and that there was residual from the vastus lateralis tear and hematoma formation.  He concluded that there were no consistent CRPS findings at that time and that the employee’s symptoms were consistent with the quadriceps tear and patellofemoral dysfunction.  The doctor also noted that the employee would be monitored for the possibility of CRPS, but he thought it not likely at that time.  The employee was referred for physical therapy and work hardening.  In January 2009, the employee was referred to Dr. Troy Erickson, an orthopedic surgeon, who discussed treatment options with the employee.  The employee chose a surgical option.

The employee underwent left knee arthroscopic surgery performed by Dr. Erickson on January 30, 2009.  The surgery included chrondroplasty of the medial femoral condyle and open repair of the suprapatellar pouch and of the quadriceps muscle.  The employee was instructed to wear a leg brace and referred for physical therapy at Mercy Hospital Moose Lake for strengthening and range of motion progress.  The employee was evaluated by Dr. Konowalchuk on April 7, 2009.  He released the employee to work with restrictions.  The employee continued physical therapy and was evaluated by Dr. Konowalchuk again on April 28, 2009.  The employee continued to report leg and knee pain but was released to work without restrictions.  On May 5, 2009, the employee was examined by Dr. Erickson, who instructed the employee to continue with home strengthening, found the employee to be at maximum medical improvement, and released the employee to return to work without restrictions.  The employee returned to work but still experienced pain after working.  On May 29, 2009, Dr. Konowalchuk prescribed a compression sleeve for the employee to use while working.

The employee continued to treat with Dr. Konowalchuk, and on September 2, 2009, reported unbearable left leg pain, swelling, purple discoloration.  The doctor noted no swelling or discoloration on examination and that temperature, sensation pulses, and skin texture were within normal limits.  He prescribed Neurontin, restricted the employee from operating heavy equipment, and referred the employee for physical therapy.  On September 14, 2009, the employee was evaluated by Dr. Konowalchuk and reported frequent color changes in his left leg.  The doctor noted that he had not seen color changes, dystrophic change, hair change or temperature alteration during his evaluations.

A September 17, 2009, MRI was read as unremarkable.  On September 21, 2009, Dr. Konowalchuk examined the employee, noting that the employee’s left leg had a mild purplish discoloration from above the knee to his toes and there was mild coolness on the left leg compared to the right leg.  He stated that the employee did not meet the criteria for RSD at that time but ordered vascular studies and a bone scan.  The vascular studies were negative and the bone scan indicated moderate asymmetric increased blood flow activity in the proximal medial left thigh to inguinal region.  Dr. Konowalchuk referred the employee to the Department of Orthopaedic Surgery at the University of Minnesota Medical Center—Fairview.  Dr. Robert LaPrade and Dr. Jeffrey Macalena examined the employee and concluded “[m]ost of his knee pain does seem to be coming from the distal aspect of his thigh as well and this seems to be most bothered by clinical examination of the hyperesthesias associated with this thigh.  This coupled with the fact that we see some superficial vascular changes in the skin that is also consistent with a complex regional pain syndrome, we would recommend follow up with a pain specialist, one who has experience with complex regional pain syndrome . . . .”  The employee returned to Dr. Konowalchuk on October 6, 2009.  The doctor referred the employee to the Mayo Clinic, which the employer denied.  The employee reported worsening pain to Dr. Konowalchuk on October 26, 2009.  The doctor noted mild discoloration on the employee’s left leg and mild lateral swelling near the surgical incision.  He assessed CRPS and indicated that the employee did not appear to be in condition to return to work as a crane operator.^[1]

On November 16, 2009, the employee was evaluated by Dr. Irfan Altafullah, a neurologist, at the employer’s request.  Dr. Altafullah noted that the employee’s left leg was cooler than the right and had a dusky color around the left knee.  He diagnosed the employee with type I chronic regional pain syndrome and recommended two lumbar sympathetic blocks.  Dr. Konowalchuk also referred the employee for possible lumbar sympathetic block.  Dr. Obioma Igboko at the Duluth Clinic Pain Management Center noted that the employee’s complaints of pain, dysesthesias, allodynia, and hyperesthesias could be the early beginnings of CRPS, and performed nerve blocks on November 19 and December 9, 2009.  The employee reported that the first block had decreased his pain, but the second block had not helped as much.  The employee attempted physical therapy, but discontinued therapy in January 2010.  Dr. Konowalchuk indicated that he had nothing more to offer the employee than palliative care and placed the employee at maximum medical improvement, but the employee was off work pending a functional capacities evaluation.

On February 1, 2010, the employee reported to Dr. Konowalchuk that his leg had a grayish discoloration the night before.  The doctor noted the area to be benign, referred the employee for pain management, and released the employee to work with restrictions.  On February 23, 2010, the employee again returned to Dr. Konowalchuk reporting worsening symptoms.  The doctor indicated that on examination, the employee’s left leg was slightly swollen and had a purplish discoloration.  He again referred the employee to the Mayo Clinic.

On March 8, 2010, the employee sought treatment for his left leg pain with Dr. Andrew Will at the Twin Cities Pain Clinic, which the employee had arranged on his own.  Dr. Will referred the employee for a psychological evaluation for a trial spinal cord stimulator.  After the evaluation, the employee was found to be a good candidate for the stimulator.  During another appointment in April 2010, mild purple hyperpigmentation of the employee’s left leg was noted.  The employee completed a spinal cord stimulator trial and reported decreased pain.  Dr. Will recommended a stimulator implant.  Dr. Konowalchuk took the employee off work pending the implant surgery.  The employee reported low back pain at an April 28, 2010, appointment with Dr. Will.  Also on April 28, 2010, the employee was examined again by Dr. Altafullah, who found that a spinal cord stimulator was not reasonable, that the employee was at maximum medical improvement, and that the employee’s mild RSD had “burnt out.”

On May 17, 2010, the employee underwent spinal cord stimulator implantation surgery, performed by Dr. Will.  The employee experienced some pain relief and was able to reduce his pain medication.  Dr. Will took the employee off work for two weeks with a gradual increase in activity for eight to twelve weeks with restrictions.  In September 2010, the employee returned for an adjustment to his stimulator.  The employee was taken off work, and in October 2010, Dr. Will indicated in a report of work ability that he did not expect the employee to return to work.  Later in October, the employee reported new onset low back pain that started after his spinal cord stimulator was adjusted on September 29, 2010.  An October 22, 2010, lumbar CT scan indicated a right L5-S1 herniation and minimal bulging at L4-5.  The employee continued to report severe low back pain radiating into the right thigh.  Dr. Will suggested a surgical consultation.

On December 1, 2010, the employee underwent a rehabilitation consultation with QRC Rachel Peterson at the Department of Labor and Industry’s Vocational Rehabilitation Unit.  Based on Dr. Will’s report that the employee was not released to work and was not likely to be able to return to work, the QRC found the employee was not eligible for rehabilitation services.

The employee continued to treat with Dr. Will through March 2011 for low back pain, left thigh pain, and new pain in his left hip.  Dr. Will opined that the employee’s lumbar disc herniation had resulted from the employee’s chronic gait disturbances and that the employee was off work due to chronic pain from his left leg injury.  Dr. Will rated the employee’s RSD condition at 20% permanent partial disability under Minn. R. 5223.0420, subp. 6A.  He testified by deposition when he examined the employee on March 8, 2010, he found no ecchymosis, swelling, deformity, atrophy, color change, hair growth differences, or temperature changes of the left leg.  He also testified that edema, changes in local skin color, osteoporosis, dyshidrosis, temperature changes, limitations in passive range of motion, and alteration of skin tone were not detected on his examinations of the employee, and that he first saw the results of the bone scan on the day of the deposition.  He stated that he does not require a finding of a certain number of symptoms when making a diagnosis of RSD, and disagreed that the employee’s RSD had “burnt out.”

On December 30, 2010, the employee was examined by Dr. Nolan Segal at the employer’s request.  Dr. Segal opined that the employee did not have CRPS or RSD, that the neurostimulator was not necessary, that the employee’s low back pain was not related to his leg injury, that the employee was capable of full-time work with restrictions, and that the employee did not sustain a permanent partial disability rating for RSD.

In an August 31, 2010, claim petition, the employee claimed that he had developed RSD in his left leg as a result of his August 6, 2008, work injury.  The employee claimed temporary partial disability benefits, temporary total disability benefits, permanent partial disability benefits, and medical expenses, including the spinal cord stimulator implantation.  The employer objected.  A hearing was held on March 29, 2011.  The record was held open for submission of Dr. Will’s deposition transcript, which was taken on April 5, 2011.  The record closed on April 25, 2011.  Also after the hearing, the parties submitted closing arguments.  In that document, the employee conceded that he could not prove that his physical condition was the cause of his wage loss in the summer of 2010 since he was working at the union scale wage and worked all hours available.  The compensation judge denied the employee’s claim for medical treatment related to the spinal cord stimulator, temporary total disability benefits, and permanent partial disability related to an RSD condition.  The compensation judge awarded the employee temporary partial disability benefits from June 6 through September 20, 2010.  The employee appeals the denial of medical treatment related to the spinal cord stimulator, temporary total disability benefits, and permanent partial disability related to an RSD condition.  The employer cross-appeals the award of temporary partial disability benefits from June 6 through September 20, 2010.

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.^[2]  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.^[3]  Fact findings are clearly erroneous if the reviewing court, looking at the entire evidence, is left with a definite and firm conviction that a mistake has been committed.^[4]  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.”^[5]

The employee contends the compensation judge erred when he found the employee failed to establish through the medical evidence that he suffers from RSD or CRPS.  The employee further contends that the Findings and Order of the judge are without substantial evidence to the extent the decision fails to consider the basic constellation of symptoms as diagnostic tools to identify his condition.  The employee maintains the judge erred as a matter of law by analyzing the question of whether the employee has CRPS under Minn. R. 5223.0420, and denying the employee’s claim for failure to meet the conditions listed in the rule.  We are not persuaded.

The central issue in the case is whether substantial evidence supports the judge’s finding that Dr. Will’s deposition testimony of April 5, 2011, and the medical records taken as a whole do not support a diagnosis of CRPS/RSD.  We review the judge’s decision under substantial evidence in view of the entire record as submitted under established legal principles.

The findings of the compensation judge are to be affirmed if they are supported by evidence a reasonable mind might accept as adequate.  The WCCA should consider the evidence which supports the compensation judge’ findings, opposing evidence, and evidence from which conflicting inferences can be drawn.  The WCCA, however, must give “due weight to the opportunity of the compensation judge to evaluate the credibility of witnesses.”  Where more than one inference may reasonably be drawn from the evidence, the compensation judge’s findings shall be upheld.^[6]

The employee states the objective test to determine the presence of CRPS is a bone scan.  His bone scan revealed a moderate asymmetric increase in blood flow activity in the affected area.  The employee argues the bone scan was not given the sufficient weight by the physicians on which the compensation judge relied.  He stated in his reply brief that the bone scan “is the gold standard, yet it was completely ignored by each adverse examiner, and consequently, by the compensation judge.”^[7]

From the date of the scan to the date of the hearing, multiple doctors reviewed the results of the bone scan and multiple medical experts came to different conclusions on whether the employee suffers from CRPS/RSD.  Dr. Konowalchuk found mild sympathetic abnormalities in 2008 and 2009.  He noted a slight decrease in temperature of the left lower leg, and markedly different coloration within the affected area before and after the date of the bone scan.  By 2010, Dr. Konowalchuk found the employee to be at maximum medical improvement with sympathetic abnormalities of swelling and discoloration.

In 2009, Dr. Altafullah found the employee met the criteria for CRPS Type I but over time Dr. Altafullah found the employee had reached maximum medical improvement and made no finding of permanent sympathetic abnormalities stating in his April 28, 2010, report that the employee’s mild RSD had “burnt out.”  Dr. Altafullah noted inconsistencies between objective findings and the employee’s subjective complaints.

Dr. Segal performed an independent medical evaluation in December of 2010 that included a medical record review.  The medical records provided to Dr. Segal included records from St. Mary’s Duluth Clinic Health System where the September 23, 2009, bone scan was performed.  In his report, Dr. Segal noted a complex recovery to the left leg after an arthroscopic debridement, stating:

Because the employee had no objective physical examination findings of CRPS or evidence of RSD, Dr. Segal concluded the employee does not have any findings consistent with CRPS/RSD.  By contrast, Dr. Will was of the opinion that CRPS/RSD is a neuropathic type of condition where hypersensitivity of the skin and complaints of pain without additional objective physical findings are valid indicators of CRPS/RSD, and concluded that the employee has an active diagnosis of CRPS/RSD.  Dr. Will testified he did not use the criteria listed in the rules to establish an active diagnosis and disability.

RSD/CRPS diagnoses are controversial and complex.  In this case, the inconsistent and divergent opinions of the medical experts increased the degree of complexity in reaching a conclusion on a diagnosis.  The employee was treated and evaluated by numerous medical doctors.  The judge provided detailed findings on the employee’s medical history from 2008 to the date of hearing in a chronological order.  The employee’s medical records clearly indicate that the employee has at times demonstrated some of the listed symptoms, including skin color changes, swelling and positive bone scan findings.  However, in finding 67, the judge concluded that the employee failed to show, through Dr. Will’s deposition testimony and the medical records taken as a whole, that he suffers from CRPS/RSD.

Conflicts in expert medical testimony and other reliable evidence to support or oppose an existing diagnosis must be resolved by the compensation judge.^[9]  The judge adopted the medical opinions of Drs. Altafullah and Segal over the medical opinions of Dr. Will.  The bone scan was an objective physical finding that was essentially given a different degree of weight by the various physicians.  It was not overlooked by the physicians on which whose opinions the compensation judge relied.  We thus find no basis to conclude the judge ignored the results of the bone scan to reach a legal conclusion.  The findings must be affirmed under the substantial evidence rule.

The employee, however, maintains the judge erred as a matter of law by analyzing the question of whether the employee has CRPS/RSD under Minn. R. 5223.0420, and denying the employee’s claim for failure to meet the conditions listed in the rule.  In Stone v. Harold Chevrolet,^[10] this court held that the presence of the listed criteria in the permanent partial disability rules is not a condition precedent to a diagnosis of RSD.  Rather, the medical records and testimony establish or defeat a diagnosis of RSD.  If the compensation judge determines that the employee has CRPS/RSD, the extent of permanent partial disability is determined by the listed conditions in Minn. Rule 5223.0430, subp. 6 or by a Weber rating.^[11]

We believe there is some confusing language in the judge’s memorandum:^[12]

The employee appeals from the compensation judge’s denial of a permanent partial disability rating.  A permanent functional impairment rating requires a disability related to the active diagnosis.  The employee failed to prove he had a current ratable condition under the statute or under Weber.  The compensation judge’s denial of a permanent partial disability rating is affirmed.

The compensation judge adopted the medical opinions of Dr. Segal and Dr. Altafullah over that of Dr. Will and found that the medical treatment related to the spinal cord stimulator was not reasonable and necessary medical treatment for the employee’s work injury.  Both Dr. Segal and Dr. Altafullah opined that the claimed stimulator implantation was not reasonable and necessary medical treatment.

The employee argues that Dr. Segal’s and Dr. Altafullah’s opinions lack adequate foundation.  To be of evidentiary value, an expert medical opinion must be based on adequate foundation.^[13]  The question of foundation goes to the competency of a witness to render an expert opinion.  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.^[14]  Foundation may be established by personal knowledge, a hypothetical question, or testimony at the hearing.^[15]  The employee argues that since the employer’s attorney informed both doctors of her personal observations of the employee’s leg condition when requesting their opinions, the foundation for the doctors’ opinion is not based on facts supported by the record.  We disagree.  Dr. Segal and Dr. Altafullah examined the employee, took a history, and reviewed his medical records.  As a general rule, this level of knowledge establishes a doctor’s competence to render an expert opinion.^[16]  The foundation for Dr. Segal’s and Dr. Altafullah’s medical opinions was based on their personal knowledge of the employee’s condition based on their examination of the employee, his history, and his medical records, not on the information given to them by the employer’s attorney.  The compensation judge did not err by relying on their opinions.

It is the compensation judge's responsibility, as trier of fact, to resolve conflicts in expert testimony.^[17]  This court will generally affirm a compensation judge’s decision based on a choice between competing medical opinions.^[18]  Substantial evidence supports the compensation judge’s finding that the medical treatment related to the neurostimulator was not reasonable and necessary medical treatment for the employee’s work injury.  Accordingly, we affirm.

The compensation judge found that the employee’s August 2008 work injury is not a substantial contributing factor to his inability to work after September 20, 2010, and that the employee’s wage loss is related to other factors such as a non-work related back condition or is the employee’s personal choice.  The employee argues that there is no evidence to support the judge’s finding that his inability to work after September 20, 2010, was related to his low back symptoms.  The employee suffers from a L5-S1 disc herniation with possible impingement of the large S1 nerve root.  Dr Segal opined that the employee’s low back condition was unrelated to the employee’s work injury.  He also opined that the employee was capable of full-time employment with restrictions, including avoiding bending, lifting, and twisting and no lifting or carrying over 40 pounds, for the employee’s low back condition.  The compensation judge could reasonably conclude that the employee’s inability to work is related to his non-work-related low back condition based on Dr. Segal’s opinion.

The judge also noted that the employee has not conducted any job search in denying the employee’s claim for temporary total disability benefits from September 21, 2010, through the dated of the hearing.  Generally, employees who are capable of working must make a diligent job search to establish total disability.^[19]  The fact that an employee has not sought post-injury work goes to the evidentiary weight of the assertion that the employee is totally disabled.^[20]

Substantial evidence supports the compensation judge’s denial of the employee’s claim for temporary total disability benefits.  We affirm.

After the hearing, the employee conceded that he could not prove that his physical condition was the cause of his wage loss in the summer of 2010 since he was working at the union scale wage and worked all hours available.  The compensation judge awarded temporary partial disability benefits from June 6 through September 20, 2010.  The employer cross-appealed the award of temporary partial disability benefits, arguing that the compensation judge erred by deciding this issue after the employee had withdrawn the issue.  On appeal, the employee does not dispute the employer’s position on this issue.  Therefore, we vacate the compensation judge’s award of temporary partial disability benefits from June 6 through September 20, 2010.