LOIS M. SIMONS, Employee, v. RIDGEVIEW MED. CTR., SELF-INSURED/BERKLEY RISK ADM=RS, Employer/Appellant, and WESTERN ORTHOPAEDICS & SPORTS MED., RIDGEVILLE MED. CTR., CONSULTING RADIOLOGISTS, RIDGEVIEW ANESTHESIA ASSOCS., and UNUM LIFE INS. CO. OF AM., Intervenors.
WORKERS= COMPENSATION COURT OF APPEALS
DECEMBER 1, 2006
CAUSATION - PERMANENT AGGRAVATION; EVIDENCE - EXPERT MEDICAL OPINION. Where the initial chart note and a letter report of the employee=s treating physician misstated the specific manner in which the employee testified that her injury took place, but the doctor=s records further revealed that the employee had corrected his misunderstanding of the events prior to his issuance of his causation opinion, the compensation judge could treat the mistake as a question of weight rather than foundation, and was not precluded from accepting the causation opinion as a matter of law. The compensation judge=s finding that the work injury was a substantial contributing cause of the aggravation of the employee=s pre-existing knee condition had substantial support in the evidence not only in the form of this expert medical opinion, but also in the fact that the employee had been asymptomatic prior to the injury and began having symptoms immediately thereafter.
Determined by Stofferahn, J., Wilson, J. and Pederson, J.
Compensation Judge: James F.. Cannon
Attorneys: Richard C. Lund, Law Offices of Donald F. Noack, Jr., Mound, MN, for the Respondent. David L. Christianson, Cronan Pearson Quinlivan P.A., Minneapolis, MN, for the Appellant.
DAVID A. STOFFERAHN, Judge
The self-insured employer appeals from the compensation judge=s finding that the employee=s June 3, 2003, work injury was a substantial contributing factor to a permanent aggravation of the employee=s bilateral knee condition. We affirm.
The employee, Lois M. Simons, was born in 1938 and is currently 68 years old. She has worked as a medical lab technician specializing in drawing patient blood samples since before 1960. She began working for the Mound Clinic in August 1978. Her work there consisted principally of drawing blood, taking throat cultures and skin scrapings, and performing blood, urine, and stool tissue tests. The employee=s work was predominantly performed while standing, with at least 80 percent of her work done in that position.
In January, 1989, the employee slipped on some stairs at the Mound Clinic and twisted her left knee. Over the next week or so, the employee had knee discomfort and some difficulty with fully flexing the knee. The Mound Clinic was also the employee=s medical provider, so she sought treatment there on January 20, 1989, where she was diagnosed with a probable left knee sprain and advised to wear a knee sleeve. The employee returned to her physician at the Mound Clinic on March 17, 1989, complaining that she had continued to have knee pain. Knee range of motion testing produced patella femoral crepitation and the femoral grind test was positive. The employee was diagnosed with post traumatic chondromalacia of the patella. An exercise program was recommended.
The employee next returned for treatment to the left knee in December 1989, reporting two days of left knee discomfort. Tenderness was localized to the medial patellar region. x-rays were negative and the cruciate ligament was intact. The employee was given Clinoril and was advised to perform quad sitting exercises.
The employee did not require further treatment until September and October 1990, when she treated twice for intermittent left knee pain accompanied with occasional clicking and popping. She was diagnosed with a chronic knee sprain. On May 21, 1991, the employee again returned to the Mound Clinic for treatment and reported that she continued to experience intermittent left knee discomfort, primarily when walking up or down stairs. The employee was referred for a trial of physical therapy and advised to restrict stair climbing at work.
The Mound Clinic records show that the employee next required treatment for her knees on November 4, 1993. She reported that she had begun having intermittent discomfort in both knees for some time and was now having increasing pain in the medial aspect of the right knee despite no specific injury. An x-ray of the right knee was unremarkable except in showing minimal joint space narrowing. The doctor prescribed Lodine and advised the employee to return for an orthopedic follow-up if her pain did not resolve.
On November 15, 1993, the employee slipped on ice outside the Clinic and fell, twisting her right knee. She sought treatment the next day and then saw Dr. James E. Johanson, an orthopedist, a few days later. Dr. Johanson noted that the employee had a varus position of the right knee at almost 10 degrees of varus. X-rays showed narrowing of the medial joint line on the right and similar narrowing, though worse, on the left. He diagnosed early degenerative changes of the medial joint line in the right knee, and recommended that the employee undergo an MRI of the right knee to rule out a medial meniscus tear. Her right knee was injected with cortisone in December 1993. The MRI was performed on December 27, 1993, and showed a probable horizontal degenerative cleavage tear in the inferior surface of the posterior horn of the medial meniscus. The employee was treated conservatively with Naprosyn and quadriceps exercises.
The employee continued to work in her usual job over the next several years without any treatment for the knees. On March 28, 1996, the employee was seen by Dr. Johanson for an unrelated problem. Dr. Johanson noted that the employee still continued to have occasional pain along the medial side of the right knee, but that this had markedly improved. He recommended she continue doing her quadriceps exercises.
Over the next seven years the employee continued working in her usual job without restrictions associated with her knees. She testified that her knees gave her very little trouble during this period and that she never missed any work due to knee problems. At some time during this period, the Mound Clinic was purchased by the employer, the Ridgeview Medical Center. The employee continued in her usual job without interruption, now as a Ridgeview employee.
On June 3, 2003, the employee had just finished drawing blood from a patient and was crossing in front of him to put a cap on the blood vial when he extended his leg, tripping her. She managed to catch herself and prevent a complete fall by grabbing onto the blood drawing table next to the patient=s seat, but as she twisted and lurched forward, she experienced a feeling of snapping and popping in the knees. She reported the injury to the clinic manager and a first report of injury was prepared, which the employee signed on June 5. In it, the employee stated that she had been tripped by a patient, resulting in a Acrack and sharp pain in right knee@ and that her left knee Anow . . . also catches & wants to collapse.@
The employee testified that she hoped that her knee pain would go away within a few days, but it continued to worsen. She began to have difficulty going up and down the stairs to her basement apartment.
The employee knew that an orthopedic physician, Dr. Robert E. Heeter, made twice-weekly visits to her workplace for patient appointments there. When he was at the clinic on June 13, 2003, the employee sought treatment from him for her knees. Dr. Heeter=s chart notes for that date state that the employee was Atripped by a patient and landed on her flexed knees@ after which she felt a pop and snap in the right knee and also had an onset of aching, soreness and swelling in the left knee. Examination showed a small effusion present in each knee as well as mild crepitation through the range of motion. X-rays showed medial compartment osteoarthritis with the medial compartment space reduced to about one millimeter. Dr. Heeter concluded that the employee=s injury had resulted in a significant aggravation of the employee=s pre-existing arthritic problems in both knees, as she had previously been asymptomatic. He recommended that the employee undergo Hyalgan injections to her knees in the hope of delaying a need for knee replacement surgery. The employee=s left knee was injected with Kenelog and Marcaine.
The employee underwent four Hyalgan injections of the left and right knees on various dates during July, August and September 2003.
At a follow-up appointment with Dr. Heeter on September 19, 2003, the doctor noted that the employee had clarified to him that she did not fall onto her flexed knees, but instead Atripped, buckling forward and catching herself,@ straining her knees in the process.
On April 23, 2004, Dr. Heeter saw the employee and noted that she continued to have knee pain despite the Hyalgan injections and would likely need total joint replacement arthroplasty in both knees.
The employee underwent knee replacement surgery in the left knee on May 26, 2004. On January 18, 2005, Dr. Heeter noted that he expected the employee=s permanent partial disability to rate at 8 percent for total condylar knee arthroplasty, based on the left knee replacement already done and in anticipation of right knee replacement A. . . for a knee that was significantly aggravated in a slip and fall work-related injury.@ The right knee surgery was performed on February 9, 2005.
The employee was seen for an examination on behalf of the self-insured employer by Dr. Mark Engasser on September 14, 2004. Dr. Engasser noted that the employee had not fallen on her knees during the June 3, 2003, work incident. He did not consider bending or twisting of the knees medically sufficient to permanently or significantly aggravate the employee=s pre-existing osteoarthritis of the knees. In his view, the June 3, 2003, work injury was mild and temporary in nature and any symptoms associated with that injury would have resolved within two or three days. Thus, he considered the employee=s disability and medical treatment after about June 6, 2003, to be wholly associated with her pre-existing condition and unrelated to the work injury. Dr. Engasser did agree that the medical treatment for the employee=s knees, including knee replacement surgery, had been reasonable and necessary for her knee problems. Because of the employee=s knee problems, Dr. Engasser recommended that the employee be restricted to light duty work, but considered that work involving 80 percent standing would be suitable.
In a letter report dated March 9, 2006, Dr. Heeter again expressed his opinion that the employee=s work injury Awas a significant aggravating factor . . . causing her arthritic knees to be decompensated with persistent, active synovitis, swelling and significant aggravation of the pre-existing condition.@ However, the doctor again in this report gave a history of injury involving the employee having fallen forward landing on flexed knees.
A hearing was held before a compensation judge on March 31, 2006, to determine, among other things, whether the employee=s June 3, 2003, work injury was a substantial contributing cause of her subsequent disability and need for total knee replacement surgery. Following the hearing, the judge found that the work injury on that date was a substantial contributing factor to a permanent aggravation of the employee=s left and right knee conditions and that her knee replacement surgeries were causally related to the work injury. The employer appeals.
At the hearing, the compensation judge was faced with the question of whether the June 2003 incident was a minor, temporary injury or whether it resulted in a permanent aggravation of a pre-existing condition. The compensation judge determined that the employee=s injury was a permanent aggravation. In his memorandum, the compensation judge referred to the fact that for at least seven years the employee had no medical treatment for her knees and worked her regular job without restrictions. The compensation judge also accepted the opinion of Dr. Heeter.
The employer argues on appeal that the medical evidence relied upon by the compensation judge lacked adequate foundation, and that substantial evidence fails to support the compensation judge=s findings on causation. Specifically, the employer points to the statements in Dr. Heeter=s initial chart note of June 13, 2003, later repeated in his March 9, 2006, letter report, to the effect that the employee=s injury involved her having fallen on flexed knees. The employee testified that she did not actually fall on her knees, but instead caught herself on the blood drawing table, after her knees twisted and she began to fall. The employer=s expert physician, Dr. Engasser, opined that a mere twisting injury to the knees could not have caused a permanent aggravation of the employee=s pre-existing bilateral knee osteoarthritis. Accordingly, the employer argues, Dr. Heeter=s opinion was predicated on a mistaken understanding of a material fact, and lacks foundation, so that the compensation judge was not entitled to rely upon it.
The competency of a witness to provide expert medical testimony depends upon both the degree of the witness= scientific knowledge and the extent of the witness= practical experience with the matter which is the subject of the offered testimony. Reinhardt v. Colton, 337 N.W.2d 88, 93 (Minn. 1983). Dr. Heeter examined and treated the employee, took her history, reviewed the relevant medical tests, and was aware of the employee=s symptoms and progress. This is a sufficient level of knowledge to establish a doctor=s competence to render an expert opinion. See, e.g., Grunst v. Immanuel‑St. Joseph Hospital, 424 N.W.2d 66, 40 W.C.D. 1130 (Minn. 1988)
However, to constitute an adequate foundation, the facts upon which an expert relies for his or her opinions must be supported by the evidence. McDonald v MTS Sys. Corp., 43 W.C.D. 83 (W.C.C.A. 1990), summarily aff'd (Minn. July 13, 1990). Certainly, Aa doctor's opinion regarding causation which is based on an inadequate factual foundation is of little evidentiary value," and may not be relied on by the compensation judge. Id. See also Medalen v. WASP, Inc., 64 W.C.D. 10 (W.C.C.A. 2003).
If Dr. Heeter had expressed the same view as Dr. Engasser, that a twisting injury would have been insufficient to cause a permanent aggravation of the employee=s knee conditions, then the employer=s argument might have greater force. However, there is nothing in any of Dr. Heeter=s records to suggest that he considered this distinction to be material to his opinion. In fact, the only information suggestive of Dr. Heeter=s reasoning in reaching his opinion is in a line in his initial chart note giving his diagnostic impression, in which he states that the employee Ahad a significant aggravation of her arthritic condition with her slip and fall event. She was asymptomatic prior to this.@ The compensation judge might reasonably infer from this statement that Dr. Heeter was relying more on the history of the employee=s symptoms than on the precise mechanism of injury in reaching his opinion on causation. Dr. Heeter did not further explain his view on causation; however, an absence of an explanation of how the mechanism of injury worked to aggravate the employee=s pre-existing condition goes to the weight rather than the foundation of a doctor=s causation opinion. Goss v. Ford Motor Co., 55 W.C.D. 316 (W.C.C.A. 1996).
In addition, it was clear from Dr. Heeter=s records that he had in fact been corrected by the employee about the mechanism of the injury, and had nonetheless continued to hold the view that the employee=s work injury had caused a significant aggravation of her pre-existing knee condition. Although the doctor=s initial misstatement of the mechanism of injury eventually was repeated in his 2006 letter opinion, the compensation judge was entitled to conclude that the doctor had simply inadvertently recopied his earlier error while reviewing his initial chart note to dictate that letter, and that he did not rely specifically on an erroneous view of the mechanism of injury in reaching his opinion on causation.
Thus the compensation judge could, by reasonable inferences from the evidence, determine that these errors in Dr. Heeter=s records did not represent a mistake of material fact sufficient to undermine the foundation for his opinion. As such, the misstatements about how the employee=s injury occurred in Dr. Heeter=s initial chart note and final written opinion figured solely in the persuasiveness or weight to be accorded the opinion. Drews v. Kohl=s, slip op. at 6 (W.C.C.A. March 28, 1996). See also Reinhardt, supra, 337 N.W.2d at 93. The compensation judge was clearly aware of the discrepancies in Dr. Heeter=s notes and letter opinion, as he discusses the matter at length in his memorandum. Despite these discrepancies, the judge adopted Dr. Heeter=s view over that of Dr. Engasser. Absent a clear foundational defect in the opinion relied upon, this court will generally affirm a compensation judge=s choice between conflicting expert opinions. Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).
Finally, we note that the compensation judge expressly relied in large part on the fact that the employee=s knees had been asymptomatic, needed no medical treatment, and occasioned no time loss from work for more than seven years leading up to the June 2003 work injury, but experienced an onset of symptoms in conjunction with that injury which have continued undiminished thereafter and which led to her need for knee replacement surgery. This history of symptoms did not comport well with Dr. Engasser=s opinion that the June 3, 2006, work injury was temporary in nature and resolved within two or three days. A compensation judge is permitted to use the fact that a condition did not preexist a work injury to support a finding of causation. Gustafson v. Mr. Carrot Inc., slip op. (W.C.C.A. Mar. 29, 1994 ), citing Laurent v. Sterling, Inc., slip op. (W.C.C.A. Mar. 9, 1994).
We conclude that the compensation judge=s determination in this case is supported by substantial evidence, and that the result is not clearly erroneous. We therefore affirm.