The employee appeals from the compensation judge’s determination that his work injury of February 12, 2003, was a temporary aggravation of a pre-existing condition.  We affirm.

This matter arises out of a work injury sustained by the employee, Eugenio Calbillo, on February 12, 2003, while he was employed by MG Waldbaum in Gaylord, Minnesota.  The issue on appeal is whether the compensation judge’s determination that the 2003 work injury was a temporary aggravation of a previous condition has substantial support in the evidence as a whole.

The employee was working as a carpenter in Texas on August 15, 1986, when he injured his low back while attempting to lift a heavy object.  The initial diagnosis at Val Verde Regional Medical Center, in Del Rio, Texas, was of a low back sprain with bilateral sciatica.  A CT scan done on September 7, 1986, was read as showing “a moderate central bulging disc at L4-5, with facet arthropathy on the left particularly, and an asymmetric left central bulge at L5-S1, somewhat more prominent-again with facet arthropathy as well.”  Surgery was done on March 3, 1987, a procedure described in the records as “a hemilaminectomy and discectomy at L4-5.”

There are no medical records in evidence of any treatment the employee might have received in Texas for his low back after surgery.  The employee moved to Minnesota in 1993.  It appears that he did not work in the period from after his surgery until his move to Minnesota but the reasons for that are unclear from the record.^[1]  The employment application with MG Waldbaum is dated August 23, 1994, and the employee apparently began his employment there shortly thereafter.  MG Waldbaum raises chickens at its facility in Gaylord.  The employee was a house person for the company.  He checked feed, water, lighting and ventilation in barns, removed dead birds from cages, conducted repair and preventive maintenance on barn equipment, and cleaned the barn.

There is no indication that the employee received medical care for his low back after his move to Minnesota.  The employee testified at the hearing that he had no difficulty with his back after his move to Minnesota and he was able to do his regular job without any problems. The employee sustained injuries to both shoulders in May 2001 while working at MG Waldbaum.  The employee treated with Dr. Scott Stevens at Orthopaedic and Fracture Clinic in Mankato and had right shoulder surgery in November 2001, and treated with Dr. Stevens through November 2002.  The treatment was limited to the shoulder.

On February 12, 2003, the employee slipped and fell on ice while walking between barns.  He reported the incident to his employer the same day.

Initially, the employee did not receive medical treatment for the slip and fall incident, opting instead to receive pain medication from the company nurse.  He first saw a doctor on April 24, 2003, when he returned to Dr. Stevens.  Dr. Stevens obtained a history that the employee had fallen on ice on February 12 and had discomfort since that time.  On the date of his visit, the employee reported low back pain and pain in his buttocks and the posterior of both legs.  X-rays taken on that date were read as showing disc narrowing and arthritic changes at the L4-5 level and, to a lesser extent, at L5-S1.

Dr. Stevens provided medication, referred the employee for physical therapy, and recommended an MRI.  The MRI, taken on June 3, 2003, showed “spinal stenosis of moderate severity at L4-5 related to enhancing epidural scarring.  No evidence for recurrent disc facet degenerative changes at L4-5 and L5-S1.  Otherwise fairly well maintained disc at other lumbar levels.  No spinal stenosis or other significant findings demonstrated.”

After the physical therapy prescribed by Dr. Stevens, the employee continued to experience low back and leg pain.  On August 3, 2003, Dr. Stevens noted the employee had not had significant relief from epidural steroid injections and the employee was referred to Twin Cities Spine Center.  The employee was placed on restrictions to avoid carrying over 10 pounds and to avoid pushing or pulling over 25 pounds.  The employee saw Dr. Darrell Dykes at Twin Cities Spine Center on September 26, 2003.  Dr. Dykes took a history of the employee’s earlier surgery and a history that the employee did very well between that surgery and the incident in February 2003.  As his impression, Dr. Dykes stated that “the patient’s history, physical examinations and studies are consistent with degenerative spondylosis, most advanced at the L4-5 level, status post laminectomy, discectomy 12 years ago.”  Given the employee’s failure to improve after treatment, Dr. Dykes recommended fusion surgery at the L4-5 level.  Dr. Dykes also placed work restrictions on the employee of no lifting above 25 pounds and no excessive lifting, carrying, pushing or pulling.

The employer and insurer had the employee’s medical records reviewed by Dr. Jeffrey H. J. Nipper, an orthopedist.  In his report, dated December 6, 2003, Dr. Nipper concluded that, although the employee may have sustained a back sprain or strain when he fell in February, the employee’s ongoing symptoms represented a natural progression of the pathology already existing in the employee’s spine.  Dr. Nipper did not believe that the employee’s work injury required further treatment.

The employee, who had continued to work for the employer, was terminated from his job on December 8, 2003.  The employee was unable to explain at the hearing the reasons for his employer’s actions.  There was no evidence from the employer on this point.

The employee returned to see Dr. Dykes on January 23, 2004.  In his chart note for that date, Dr. Dykes addressed the question of causation.  “While it is clear that this patient has a degenerative process and previous treatment for his back, he did have over 18 years of good function without symptoms until his fall at work in February 2003.  Accordingly, it is my opinion, to a reasonable degree of medical certainty that his current symptoms and need for the proposed treatment are directly related to his work injury of February 2003.”

The employee filed a claim petition in January 2004, seeking wage loss benefits after December 8, 2003, and medical benefits including authorization for the surgery proposed by Dr. Dykes.  The employer and insurer denied primary liability, denied notice and denied that the employee was entitled to any workers’ compensation benefits.

The employee was seen for an IME by Dr. Paul Wicklund on May 4, 2004.  Dr. Wicklund reviewed medical records but it does not appear from his report that he saw any of the records from the employee’s treatment in 1986 and 1987.  In his report of May 6, 2004, Dr. Wicklund stated that, in his opinion, “the employee’s slip and fall in February was a temporary low back contusion and sprain.”  Dr. Wicklund expressed doubt that surgery was appropriate and stated that, in any event, any treatment needed was not due to the work injury.

The employee’s claim petition was heard by Compensation Judge Kathleen Behounek on March 2, 2005.  In her Findings and Order of July 29, 2005, the compensation judge determined that the employee had sustained a work injury on February 12, 2003, and had provided appropriate notice of that injury to the employer.  She found that the work injury was a temporary aggravation of his pre-existing lumbar condition which lasted three months and denied the employee’s claims for benefits.  The employee appeals.

On appeal, the employee argues that the compensation judge erred in concluding that the employee’s work injury was a temporary aggravation of a pre-existing condition.^[2]  According to the employee, the compensation judge failed to apply the appropriate legal standard in determining whether an injury is permanent or temporary in that she failed to apply the factors set forth in McClellan v. Up North Plastics, slip op. (W.C.C.A. Oct. 18, 1994).^[3]

In McClellan, this court identified a number of factors which a compensation judge may consider in determining whether an aggravation of a pre-existing condition is permanent or temporary.  Those factors are: (1) the nature and severity of the pre-existing condition and the extent of restrictions and disability resulting therefrom; (2) the nature of the symptoms and extent of medical treatment prior to the aggravating incident; (3) the nature and severity of the aggravating incident and the extent of restrictions and disability resulting therefrom; (4) the nature of the symptoms and extent of medical treatment following the aggravating incident; (5) the nature and extent of the employee’s work duties and non-work activities during the relevant period; and (6) medical opinions on the issue.

This court has not stated that use of the McClellan factors by a compensation judge is mandatory.  Further, the parties introduced evidence on all of the McClellan factors, and it is clear from her decision and memorandum that the compensation judge considered this evidence despite the fact that she did not specifically cite to McClellan.  Further, the employee, in his brief, does not identify any McClellan factors which were ignored by the compensation judge but argues instead that consideration of the McClellan factors should have led to a different result.  The question for this court however, is not whether a different decision from the compensation judge was possible but whether substantial evidence supports the compensation judge’s decision.  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 37 W.C.D. 235, (Minn. 1984).

We find substantial evidence to support the compensation judge’s decision.  After his evaluation of the employee for low back pain on April 24, 2003, Dr. Steven’s initial impression was of degenerative disc disease with possible disc bulge and he ordered an MRI.  The MRI, according to Dr. Stevens, did not show disc bulge, and Dr. Stevens stated in his chart note of June 5, 2003, that the MRI “demonstrates a prior laminectomy on the left side at L4-5 along with the very degenerative disc disease and evidence of moderate spinal stenosis.  This is thought to be related to epidural scarring rather than recurrent disc extrusion . . .” (emphasis added).  These findings and comments suggest that the employee did not injure a disc in his February 2003 injury and that his symptoms were due to his previous back condition.  In her memorandum, the compensation judge referred to the significance of these findings.

Contrary to the statement of the employee in his brief, Dr. Stevens did not provide an opinion that the employee’s ongoing symptoms were the result of his 2003 work injury.  Dr. Dykes provided an opinion in his January 23, 2004, chart note that the employee’s condition was related to his 2003 work injury but based his statement almost completely on the reported lack of symptoms for the past 18 years.  He did not address the MRI findings.  In contrast, both Dr. Nipper and Dr. Wicklund, who provided opinions on causation at the request of the employer and insurer, noted the objective findings and testing and concluded that the employee’s present condition was the result of an ongoing degenerative process and not the result of his 2003 slip and fall.

The lack of treatment for a number of years before the 2003 work injury and the ability of the employee to work without restrictions before the 2003 injury are important factors, but they do not mandate a finding that the employee’s 2003 injury was the cause of his ongoing symptoms.  The opinions of Drs. Nipper and Wicklund provide the basis for a conclusion by the compensation judge that the employee’s 2003 work injury was a temporary aggravation which resolved after three months.

Given this evidence, we conclude that substantial evidence supports the compensation judge’s determination that the employee’s work injury of February 12, 2003, was a temporary aggravation of his previous condition.  The decision of the compensation judge is affirmed.