DANIEL INFANTE, Employee, v. CEMSTONE PRODS. CO. and STATE FUND MUTUAL INS. CO., Employer-Insurer, and CEMSTONE PRODS. CO. and ST. PAUL COS., Employer-Insurer/Appellants, and WESTERN ORTHOPEDICS, CENTER FOR DIAGNOSTIC IMAGING, HICKOK & SCHULTZ, ABBOTT NORTHWESTERN HOSP., INSTITUTE FOR LOW BACK & NECK CARE, RIDGEVIEW MEDICAL CTR., CONCRETE PRODS. COS. TRUST, ALLINA HOME OXYGEN & MEDICAL EQUIP., and METROPOLITAN ORTHOTIC LAB., Intervenors.

 

                                 WORKERS= COMPENSATION COURT OF APPEALS

                                                             FEBRUARY 14, 2003

 

HEADNOTES

 

CAUSATION - SUBSTANTIAL CONTRIBUTING CAUSE.  Substantial evidence, including expert medical opinion, supported the compensation judge=s decision that the employee=s disability and need for treatment were substantially caused by the employee=s 2001 work injury but not by earlier work injuries, which the compensation judge reasonably found to be temporary.

 

Affirmed.

 

Determined by Wilson, J., Rykken, J., and Stofferahn, J.

Compensation Judge:  Carol A. Eckersen.

 

OPINION

 

DEBRA A. WILSON, Judge

 

The employer and St. Paul Companies appeal from the compensation judge=s decision that the employee=s December 3, 2001, work-related low back injury permanently aggravated his preexisting low back condition and substantially contributed to his disability and need for medical treatment, including surgery, following the injury.  The employer and St. Paul Companies also appeal from the judge=s determination that earlier work injuries were merely temporary.  We affirm.

 

BACKGROUND

 

The employee has worked for Cemstone [the employer], or its predecessor corporation,^[1] since 1974, employed the entire time as a Aready mix@ truck driver, delivering concrete to construction sites.  In addition to driving the truck, the employee was at times required to climb a ladder on the truck to add chemicals to the concrete, to wash the truck, and to wash and rehang the concrete chute on the truck.  The employee estimated that steel chutes weighed from 55 to 70 pounds, aluminum chutes from 35 to 45 pounds.  He delivered from four to seven loads of concrete a day and would apparently wash and rehang the chutes after each delivery.

 

The employee=s medical records contain a history of sporadic low back complaints dating back to at least 1978, when he slipped on some steps at home, landing on his back.  X-rays taken following this incident were read to disclose some narrowing at L4 on the right.  In July of 1980, the employee was involved in a rear-end motor vehicle collision, after which he treated primarily for cervical symptoms, but he also mentioned low back pain during periods of hospitalization to treat neck pain after the accident.  Eight years later, in 1988, while hospitalized for suspected meningitis, the employee again complained of some low back symptoms.  However, lumbar x-rays taken during this hospitalization were read to be negative, and there is no evidence of any ongoing treatment or recommended restrictions related to low back complaints following any of these incidents.  The employee testified, in fact, that he experienced no residual low back pain after either the 1978 fall or the 1980 motor vehicle accident and that he did not specifically remember experiencing back pain during his 1988 hospitalization.

 

On October 13, 1994, the employee fell at least four to six feet from his ready mix truck into a hole at a construction site, landing on an I-beam and striking his right hip and low back.  The employee was diagnosed with low back strain with right hip pain and was advised to observe certain restrictions on his work activities.  By November 28, 1994, after physical therapy, he was back at his regular job, without restrictions, and physicians concluded that he had reached maximum medical improvement [MMI], with no residual permanent partial disability.  The employer and its insurer at the time, State Fund Mutual Insurance Company [State Fund], evidently paid medical expenses and 3.4 weeks of wage loss benefits.

 

The employee sustained a second work-related injury on August 8, 1996, when his truck hit a bump in the road, causing him to bounce and strike his head on the roof of the cab.  He was seen that same day for complaints of neck pain and headaches and was advised to rest at home.  Within a few days, he also reported low back pain, with pain down the left leg to the knee.  Dr. Richard Edwards, who performed an orthopedic evaluation, eventually reported that the employee had a long history of degenerative arthritis of the low back.  While recommending that the employee use aluminum rather than steel chutes, at least for a few weeks, Dr. Edwards released him to work without restrictions as of September 6, 1996.  The employer and State Fund paid 1.2 weeks of wage loss benefits related to this incident.

 

The employee performed his usual job with the employer, without further low back treatment or specific formal restrictions, for the next five years.  He testified, however, that he was able to use a truck with aluminum chutes until 1998 or 1999 and that he believed that he was permanently restricted to using aluminum chutes.  He also testified that he had continuing occasional low back symptoms after the August 8, 1996, incident, that he somewhat modified his activities at home and work, and that he did not seek further treatment because he thought nothing could be done.

 

On October 12, 2001, the employee was seen by Dr. Peter Schmitz for bilateral knee symptoms.^[2]  During this appointment, the employee also complained of low back symptoms Asince a truck accident, which occurred six years ago.@  X-rays revealed Asevere arthrosis of the facet joints at L4-5 and decreased disc space at L4-5,@ and Dr. Schmitz recommended an MRI.  Approval for the MRI was evidently refused by the employee=s health insurer and by State Fund.  In a report dated November 13, 2001, Dr. Schmitz indicated that the employee=s current low back condition was related to the accident of Aapproximately six years ago,@ that the employee had reached MMI but still had mechanical symptoms, and that the employee had a 3.5% whole body impairment.

 

By letter dated November 17, 2001, the employee=s attorney notified the employee of Dr. Schmitz=s report, enclosing two copies of a claim petition seeking benefits related to the employee=s October 13, 1994, and August 8, 1996, work injuries.  The employee signed one of the copies, and the claim petition was served on the employer and State Fund by mail on December 7, 2001.  In the meantime, on December 3, 2001, the employee was allegedly involved in another work-related incident while driving his truck.  St. Paul Companies was the employer=s workers= compensation carrier on this date.

 

The employee testified that, on the morning of December 3, 2001, his truck hit a Aswale@ in the road, causing his truck seat to bottom out, and he heard something Apop@ in his back and felt immediate low back and radiating left leg pain and numbness.  When seen by Dr. Joseph Van Kirk that same day, the employee reported the work incident, indicating also that he had had two past back injuries and Ahas recently been having more difficulty.@  Dr. Van Kirk prescribed a prednisone Aburst and taper@ and scheduled an MRI scan, which was performed a few days later.  When the employee saw Dr. Schmitz again on December 14, 2001, Dr. Schmitz did not record any history of the December 3, 2001, incident in his chart notes.  However, in response to a letter from the employee=s attorney, Dr. Schmitz later reported that the employee had in fact informed him of the December 3, 2001, incident at work.

 

The employee underwent facet injections and was then seen by Dr. Robert Heeter, on referral from Dr. Schmitz, on February 5, 2002.  Dr. Heeter ordered an EMG and bone scan and indicated that the employee was unable to work.  The employee continued to complain of Asignificant low back pain with a radicular component@ and experienced a worsening of his symptoms in mid March of 2002, for which he was hospitalized.  He was then referred to Dr. Richard Salib, who diagnosed degenerative spondylolisthesis at L4-5, with central spinal stenosis.  On April 17, 2002, the employee underwent surgery consisting of a posterolateral fusion, bilateral laminectomy, and anterior interbody fusion at L4-5, with implantation and bone graft.  He has been off work since the surgery.

 

The matter came on for hearing before a compensation judge on June 27, 2002, for resolution of the employee=s claim for various benefits from State Fund and/or St. Paul Companies as a result of the injuries of October 13, 1994, and August 8, 1996, and/or an alleged injury of December 3, 2001.^[3]  State Fund asserted that the 1994 and 1996 injuries were merely temporary; St. Paul Companies denied primary liability for the alleged injury of December 3, 2001.  Evidence included the employee=s medical records, the deposition testimony and reports of Dr. Salib, the deposition testimony and report of Dr. David Boxall, St. Paul Companies= independent medical expert, and the report of Dr. John Dowdle, State Fund=s examiner.  The primary issue was medical causation for the employee=s low back condition and need for fusion surgery.

 

In a decision issued on September 9, 2002, the compensation judge concluded that the employee=s injuries of October 13, 1994, and August 8, 1996, were merely temporary and that the effects of those injuries had ended well prior to the period at issue in these proceedings.  The compensation judge also determined, however, that the employee had sustained a work-related low back injury on December 3, 2001, as claimed, which had permanently aggravated his preexisting low back condition, and which was a substantial contributing cause of his disability and need for medical care, including surgery, thereafter.  St. Paul Companies was therefore ordered to pay the claimed wage loss and medical expense benefits.  St. Paul Companies appeals.

 

STANDARD OF REVIEW

 

In reviewing cases on appeal, the Workers= Compensation Court of Appeals must determine whether Athe 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 (1992).  Substantial evidence supports the findings if, in the context of the entire record, Athey 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, A[f]actfindings are clearly erroneous only if the reviewing court on the entire evidence is left with a definite and firm conviction that a mistake has been committed.@  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).  Findings of fact should not be disturbed, even though the reviewing court might disagree with them, Aunless 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.@  Id.

 

DECISION

 

1.  Nature of the December 3, 2001, Injury

 

St. Paul Companies contends that substantial evidence does not support the judge=s decision that the December 3, 2001, incident permanently aggravated the employee=s low back condition.  In support of this argument, St. Paul Companies emphasizes the evidence concerning the existence of a preexisting low back condition, including the employee=s testimony that he was never entirely symptom free after the 1994 work injury and that he somewhat modified his activities after the 1996 incident.  St. Paul Companies also relies heavily on the testimony of Dr. Salib, who indicated that the degeneration in the employee=s lumbar spine developed over many years and that, if an MRI scan had been performed immediately prior to the December 3, 2001, incident, it would have disclosed results virtually identical to the scan taken a few days after the work incident.  Finally, St. Paul Companies asserts that the compensation judge did not adequately analyze the record on this issue under the factors enumerated in McClellan v. Up North Plastics, slip op. (W.C.C.A. Oct. 18, 1994), which indicates as follows:

 

Several factors may be considered when determining whether an aggravation of a pre-existing condition is temporary or permanent, including: (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.  AWhich of these factors are significant in a particular case and the weight to be given to any factor is generally a question of fact for the compensation judge.@  Wold v. Olinger Trucking, Inc., slip op. (W.C.C.A. Aug. 29, 1994).

 

Id.  St. Paul Companies= arguments are not persuasive.

 

The compensation judge=s findings reflect a detailed consideration of the medical evidence relating to each of the employee=s injuries and to the employee=s condition following each injury.  Furthermore, in her memorandum, the judge discussed additional issues relevant to the December 3, 2001, injury, explaining as follows:

 

The employer and St. Paul Companies argue that the employee=s claim of an injury is not credible because Dr. Schmitz=s December 14, 2001 note does not record a history of the mechanism of injury.  He testified that he told Dr. Schmitz.  Dr. Schmitz later noted the history of the injury and agreed that the incident was a substantial contributing cause of Mr. Infante=s low back condition and need for surgery.  I found the employee=s testimony and Dr. Schmitz=s letter to be credible and persuasive on this issue.  The employee met his burden of proving that he sustained an injury on December 3, 2001.

 

The employer and St. Paul Companies also argued that the employee filed a Claim Petition on December 11, 2001 that did not include the December 3, 2001 date of injury.  The employee=s signature is dated December 7, 2001.  They argue that the December 3, 2001 incident is so insignificant that it was not even claimed on the Claim Petition or that this omission raises more questions about the employee=s credibility.  The Claim Petition was later amended to add the additional date of injury.  The employee=s testimony that he signed the Claim Petition form in his attorney=s office before it was completed and filed adequately explains why the December 3, 2001 date of injury was not included at that time.

 

The December 3, 2001 injury was a permanent aggravation of the employee=s low back condition.  The employee described severe low back pain with pain and numbness radiating to his right leg.  Mr. Infante missed more time from work following this injury than he missed following either of the two prior work injuries.  For the first time, surgery was considered and then performed.  Mr. Infante has been off work since Dr. Heeter recommended that he stop working.  The preponderance of the evidence leads me to conclude that the December 3, 2001 injury was a substantial contributing aggravation of the employee=s low back condition.

 

The judge=s decision illustrates that she adequately considered the evidence relevant to medical causation, and her rationale is supported by the record.  We would also note that the judge=s decision as to causation is supported by the March 29, 2002, report of Dr. Dowdle, who indicated that, if the employee=s complaints at the time did not respond to conservative care, the 2001 injury would be considered to be a Apermanent aggravation of [the employee=s] underlying degenerative disc condition.@  The employee=s complaints were not in fact alleviated by conservative care and he went on to require a complicated fusion procedure, performed less than a month after Dr. Dowdle=s examination.  The judge=s decision is also supported by the deposition testimony of Dr. Salib, who testified that the December 3, 2001, work injury was by far the primary cause of the employee=s need for surgery and time off, despite the fact that the lumbar degeneration was longstanding,

 

[b]ecause prior to the event he was able to work, carry on normal activities with minimal limitations, and following the incident he became disabled by the pain, developed weakness in the leg, essentially a foot drop, neurological deficit which did not precede the December 3, 2001 incident.

 

In fact, Dr. Salib=s testimony alone provides more than adequate support for the judge=s causation decision.  See Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).  We therefore affirm the judge=s decision that the incident of December 3, 2001, permanently aggravated the employee=s preexisting condition and substantially contributed to the employee=s disability and need for medical care, including surgery.

 

2.  Nature of the 1994 and 1996 Injuries

 

St. Paul Companies also contends that substantial evidence does not support the judge=s decision that the 1994 and 1996 injuries were merely temporary.  We acknowledge that there is evidence that would support attributing some ongoing responsibility to the 1994 and/or 1996 injuries and, therefore, to State Fund.  As previously noted, the employee indicated that he had continuing low back symptoms after both injuries and that he modified his work and home activities and considered himself restricted to using aluminum concrete chutes at work after the 1996 injury.  In addition, Dr. Salib indicated that the 1996 injury was responsible for 7% of the employee=s ongoing disability and need for surgery,^[4] and Dr. Schmitz assigned the employee a 3.5% whole body rating in November of 2001, which he attributed to the 1994 and 1996 work injuries.  The fact remains, however, that the employee was not subject to any formal continuing restrictions after either of these injuries and that he was able to return to his usual job without the need for time off and without seeking additional medical care for low back symptoms from September 6, 1996, until at least October of 2001.  Finally, both Dr. Dowdle, State Fund=s examiner, and Dr. Boxall, St. Paul Companies= own examiner, indicated that the 1994 and 1996 injuries were merely temporary.  As such, while the record might also support assigning some ongoing responsibility to the 1994 and 1996 injuries, we cannot conclude that the judge erred by finding these injuries to be temporary.  We therefore affirm the judge=s decision on this issue as well, together with her order requiring St. Paul Companies, alone, to pay the awarded benefits.