JERRY A. KEPPERS, Employee/Cross-Appellant, v. RED WING SHOE CO., SELF-INSURED/CONSTITUTION STATE SERVS., Employer/Appellant, and MAYO CLINIC, FAIRVIEW RED WING MED. CLINIC, and FAIRVIEW RED WING HOSP., Intervenors.
WORKERS’ COMPENSATION COURT OF APPEALS
APRIL 30, 2010
EVIDENCE - RES JUDICATA. Where there was an unappealed finding in a previous proceeding that the employee’s injury was a substantial cause of his “ongoing” knee problems, where the judge suggested in his memorandum that this finding had res judicata effect on the employee’s entitlement to more recent periods of wage replacement and different medical benefits, but where there was no evidence of actual application of res judicata principles in the judge’s current findings and orders, the compensation judge’s suggestion that res judicata applied was erroneous, but not to the extent of mandating reversal of the judge’s findings and order.
CAUSATION - SUBSTANTIAL EVIDENCE. Where the employer contended that the employee’s work-related knee injury was completely resolved by means of a 2008 arthroscopic meniscus repair and that his ACL problem pre-existed his 2006 work injury, where the only pre-injury ACL abnormality was a fraying that was fully repaired in 2005, where the employee’s ACL was now partially torn, and where the judge’s decision was supported by expert medical opinion, the compensation judge’s conclusion that the employee’s work injury was a substantial factor in his need for total knee replacement was not clearly erroneous and unsupported by substantial evidence.
MEDICAL TREATMENT & EXPENSE - REASONABLE & NECESSARY; MEDICAL TREATMENT & EXPENSE - SURGERY. Where the employee was diabetic and had a nonhealing infection in his right knee, where the employer’s medical expert had opined that any need for the recommended total right knee replacement was neither causally related to the work injury nor reasonable and necessary given the infection, and where the judge had found the need for the surgery causally related to the work injury but not reasonable and necessary given the infection, the compensation judge’s denial of total knee replacement in reliance on the employer’s doctor’s opinion was not clearly erroneous and unsupported by substantial evidence, notwithstanding the doctor’s contrary causation opinion.
Determined by: Pederson, J., Wilson, J., and Stofferahn, J.
Compensation Judge: Gary P. Mesna
Attorneys: T. Michael Kilbury, Peterson, Logren & Kilbury, St. Paul, MN, for the Cross Appellant. Brian J. Holly, Aafedt, Forde, Gray, Monson & Hager, Minneapolis, MN, for the Appellant.
WILLIAM R. PEDERSON, Judge
The self-insured employer appeals from the compensation judge’s application of principles of res judicata and from his awards of wage replacement and medical benefits, and the employee cross-appeals from the judge’s denial of the employee’s request for surgery. We affirm.
The first reference to Jerry Keppers’ right knee in his medical records is on August 24, 1999, when he was seen regarding pain that he had felt in the knee during a night of dancing, after a “pop” that his sister had heard at the time. An MRI scan was conducted on August 27, 1999, and was read as normal, except in that the posterior horns of the lateral and medial menisci revealed some “lamellation” and that of the latter also appeared somewhat frayed, although no clear-cut tear was identified. Later that same year, on September 27, 1999, Mr. Keppers tore his right quadriceps tendon when he fell at home, following which he underwent immediate open surgical repair. He retore the same right quadriceps tendon on November 12, 1999, when he slipped and fell on some steps, again at home. These injuries resulted in several surgeries in late 1999 and the spring of 2000, several of them in an attempt to mitigate a staph infection complicated by Mr. Keppers’ diabetes. Medical records four years later, in May of 2004, indicate that Mr. Keppers sustained an abrasion of his right knee in that year as well, which seemed, again perhaps due to his diabetes, to be taking a long time to heal.
Mr. Keppers sought treatment for his right knee again in November of 2005, after it “popped out and went back in” while he was in the process of mowing his lawn. After physical therapy and injection treatment apparently proved ineffective, on December 2, 2005, orthopedic surgeon Dr. Everett Hughes performed arthroscopic surgery on the knee, which resulted in debridement of the medial femoral condyle, removal of multiple loose chondral fragments, and debridement of the medial and lateral menisci. According to the operative summary, the arthroscopy also revealed
what appeared to be significantly frayed edges of the lateral side of the ACL which had become loose and were impinging in the lateral compartment. These were debrided with the shaver and we were able to better visualize the lateral compartment. At that point there were no significant degenerative changes of the lateral compartment.
Mr. Keppers was still in some pain on January 10, 2006, and he accepted Dr. Hughes’ recommendation of Supartz injections. Mr. Keppers apparently had a good result from the treatment by the end of the month, and he was released to work without restrictions.
On July 20, 2006, Mr. Keppers [the employee] sustained a work-related injury again to his right knee when he tripped over a pallet and fell and landed directly on the front of the knee, in the course of his work making leather boots with Red Wing Shoe Company [the employer], for whom he had apparently worked for over eighteen years. Subsequent to his injury, the employee was restricted from working for twenty-four hours and was then instructed by his doctor for a month to “take it easy.” On August 23, 2006, about a month after the injury, the employee was terminated by the employer, evidently for failure to adhere to appropriate call-in protocols. The employee had been forty-six years old on the date of his injury and had been earning a weekly wage of $558.00. The employer, which was self-insured against workers’ compensation liability at the time, admitted liability for the injury and commenced payment of various benefits.
On December 13, 2006, the employee was examined for the employer by orthopedic surgeon Dr. Richard Strand. In his report on December 19, 2006, Dr. Strand diagnosed contusion of the right knee anterior extensor mechanism, status post extensive surgeries for quadriceps rupture and degenerative arthritis of the right knee, together with degenerative arthrosis of the right knee, status post septic knee arthritis, status post arthroscopic decompression. Dr. Strand opined that the underlying cause of the contusion was the employee’s fall on July 20, 2006, that the degenerative arthritis was due to apparently pre-existing malalignment of his patella together with his subsequent quadriceps tendon rupture and associated surgeries for infections, and that the underlying cause of the arthrosis was the employee’s age, size, weight, previous severe injuries to his extensor mechanism, and septic arthritis in the knee. The doctor opined that the employee’s contusion work injury was not the cause of his current complaints, which the doctor concluded were due to extensive pre-existing disease and were being magnified. It was the doctor’s opinion that treatment for the contusion of the employee’s patella was reasonable and necessary at the time but that that injury was now healed and ongoing problems were not work related. Dr. Strand indicated that in his opinion the employee was not in need of any further treatment for his work-related contusion, although, regardless of causation, he might eventually need treatment for his degenerative arthritis. The doctor opined that the employee was not at the time of the examination a candidate for total knee replacement, there being no evidence that such surgery would relieve his knee disease, and given the employee’s severe cardiac disease, diabetic neuropathy, and history of knee infection. Concluding that the employee was “far more functional than he says he is,” Dr. Strand indicated that the only restrictions required by the employee would be restrictions on extended standing, climbing, stooping, and walking, related to the employee’s degenerative arthritis. Dr. Strand concluded that the employee had already reached maximum medical improvement [MMI] with regard to his July 20, 2006, work injury, probably within about six weeks of the incident. Finally, the doctor concluded that the employee’s July 20, 2006, work injury was a temporary aggravation of a pre-existing condition and that the employee had not sustained any permanent partial disability as a result of it.
On June 25, 2007, with symptoms persisting in the employee’s right knee, the employee’s surgeon, Dr. Hughes, issued a narrative report to the employee’s attorney. In his report, the doctor recommended a diagnostic arthroscopy of the employee’s right knee, the employee being unable to have an MRI scan, given the placement of a cardiac defibrillator in his chest. Noting that the employee “had essentially complete resolution of his symptoms” following his previous arthroscopy in 2005, Dr. Hughes went on to indicate that, in his opinion, the employee’s current right knee condition, need for restrictions, and need for the recommended surgery were all directly related to his July 20, 2006, work injury.
On August 16, 2007, the employee filed a claim petition, alleging entitlement to various benefits consequent to his July 20, 2006, work injury, including temporary total disability compensation, rehabilitation services, and the arthroscopic surgery recommended by Dr. Hughes.
On December 17, 2007, Dr. Strand issued to the employer’s attorney another evaluation of the employee’s medical condition, based on a review of his earlier examination findings together with subsequent and additional medical records. In his evaluation, Dr. Strand opined that the underlying cause of the employee’s current knee condition was totally unrelated to his work-related contusion of July 20, 2006. He concluded further that there was no evidence that the employee suffered any permanent partial disability as a result of his work injury, and he did not believe that the employee was at that time in need of any further medical care or treatment related to that injury. Moreover, it was his opinion, finally, that the repeated arthroscopic diagnostics and debridement that the employee had undergone were “not helpful” and that the employee was
a poor candidate for arthroscopic surgery [in] that he has severe cardiac disease, he has poorly controlled diabetes mellitus, and he has peripheral neuropathy changes at this time and certainly, even if he did have an anterior cruciate ligament tear, no one would recommend a reconstruction of his anterior cruciate ligament with his severe medical problems and his age.
The matter eventually came on for hearing on January 4, 2008. By findings and order filed March 3, 2008, the compensation judge concluded in part that the employee’s 2006 work injury was “a substantial aggravating and contributing cause of” his ongoing right knee problems and that the proposed arthroscopic surgical procedure was reasonable and necessary to cure or relieve the effects of that injury. The judge denied, however, the employee’s request for temporary total disability benefits continuing from January 8, 2007, because the employee had not made a diligent effort to find employment within his restrictions. A rehabilitation consultation was ordered, and on April 8, 2008, the employee underwent the consultation with QRC Bill Rutenbeck and was found to be a qualified employee for rehabilitation assistance. On that same date, Dr. Hughes restricted the employee from working until after his surgery, including a possible anterior cruciate ligament [ACL] reconstruction.
On April 10, 2008, Dr. Hughes performed the recommended surgery - - a right knee arthroscopy, partial medial meniscectomy, and debridement of notch scar tissue. In his post-operative report, Dr. Hughes noted in part that there were grade 3 and 4 changes to the medial femoral condyle, that the medial meniscus was torn, and that the ACL was observed to be partially torn. Dr. Hughes indicated that he had performed only the meniscectomy and not addressed the ACL, because it was deemed unlikely to benefit from any type of reconstruction.
Subsequent to his surgery, the employee was restricted from all work, and on April 14, 2008, he commenced physical therapy. He apparently did not have a good result from his surgery, and his symptoms actually seemed to get worse with the therapy. On May 15, 2008, QRC Rutenbeck wrote to the employer’s claims representative, Phil Rendina, advising him that he understood from the employee that Dr. Hughes had implied that the employee might eventually require a total knee replacement. On May 20, 2008, Dr. Hughes released the employee to return to work at only sedentary employment, noting that he had “[q]uite significant degenerative changes to his knee with problems with persistent pain and instability.” On June 4, 2008, QRC Rutenbeck administered some vocational testing, and attention was given to developing an appropriate vocational plan. No formal job search was immediately commenced, however, apparently in light of the possibility of further surgery in the near future.
On August 6, 2008, the employee’s physical therapist noted “an open area on the [right] kneecap itself,” about the size of a dime, that was “through the layers of the skin” and “actually deep into the fascial tissue and nearly expos[ing] the tendon.” The therapist had a physician and some wound specialists examine the lesion, and it was treated with a dressing and some ointment. With injection therapy and physical therapy proving essentially ineffective in relieving the employee’s pain, on August 12, 2008, Dr. Hughes formally recommended a total knee replacement. The doctor noted on that date that the employee “does have an area of difficult healing from an injury to the anterior aspect of his knee, but there is no distinct infection going on.” Upon this surgical recommendation by Dr. Hughes, all vocational planning was put on hold.
On August 22, 2008, the employee was seen by his primary doctor, Dr. Karl Molenaar, apparently with regard to Dr. Hughes’ surgical recommendation. Dr. Molenaar noted that the employee had “bumped [his knee] a number of months ago and unfortunately he has developed an ulcer in this area.” The doctor diagnosed “[d]iabetic wound” and recommended that the employee “cannot have knee surgery while this is an open wound.” On August 27, 2008, the employee saw in consultation Dr. Thomas Blee, on referral from Dr. Molenaar. Dr. Blee reported “a hematoma and an open sore on the kneecap,” caused by an “injury about six months ago where he fe[l]l on his right kneecap” and “developed a hematoma and an open sore on the kneecap.” Dr. Blee noted further, “Visible at the base of the wound is the bursa over the knee joint,” concluding, “This is going to take a long time to heal.” The infection was still worsening on September 5, 2008, and Dr. Molenaar admitted the employee to the hospital, where Dr. Hughes performed on that date a right prepatellar bursectomy, with irrigation, debridement, and closure of the anterior knee wound.
The employee was examined another time by Dr. Strand on September 24, 2008. In his report on that date, Dr. Strand reiterated his opinion that the employee’s July 20, 2006, contusion work injury was not in any way related to his current right knee problems. He opined also that, given his cardiac and diabetic neuropathy conditions, the employee was not a candidate for a total knee arthroplasty. The doctor then went on to state that the
present infection in [the employee’s] knee could certainly cause an osteomyelitis in the patella, which is a problem. The infection in his knee as it is right now is in danger of needing significant ablative surgery, and a total knee in this gentleman, in my opinion, would be very dangerous, I am fully sure. Total knee arthroplasty with an infection could result in an amputation.
Any need for a total knee replacement was, the doctor opined, caused by a degenerative arthritis that pre-existed the employee’s work injury and that was neither significantly aggravated nor accelerated by that work injury. Dr. Strand recommended that, due to his diabetic and cardiac problems and the open and draining wound to his knee, the employee should be restricted to sedentary work only, adding that there were no restrictions resulting from his July 20, 2006, work injury. The doctor reiterated that the employee had reached MMI from his work injury by the date of his previous examination on December 13, 2006. Finally, Dr. Strand repeated that the employee was “in a reasonably dangerous situation where any invasive surgery could result in significant disaster . . . . The most important fact in this man’s condition now is his diabetes and the previous infection in his knee, which would make it, in my opinion, foolish to attempt a total knee arthroplasty.”
A month later, in a letter to Mr. Rendina dated October 24, 2008, QRC Rutenbeck confirmed an earlier suggestion to Mr. Rendina “that we initiate job placement services if there is going to be a significant delay regarding the employee’s knee replacement surgery.” On November 3, 2008, the employer filed a Notice of Intention to Discontinue [NOID] the employee’s temporary total disability benefits, based on Dr. Strand’s report of September 24, 2008, and on a contention that the infection in the employee’s right knee was unrelated to his work injury and constituted a superseding intervening cause of any ongoing disability, the work injury being therefore not a substantial contributing factor in the employee’s current disability. On November 11, 2008, the employee was referred by QRC Rutenbeck to a job placement specialist for the purpose of initiating a job search.
On November 20, 2008, Dr. Hughes issued another narrative report to the employee’s attorney, in which he reiterated his recommendation of total knee replacement. He expressed further in his report his opinion that the employee was not yet at MMI and was likely to have substantial improvement in the performance of daily functions as a result of the recommended surgery. The doctor acknowledged the employee’s multiple other medical conditions, including diabetes and smoking and cardiac problems, but he concluded that these conditions did not preclude the employee from pursuing the recommended total knee arthroplasty. Finally, Dr. Hughes reiterated his opinion that the employee’s work injury of July 20, 2006, “caused substantial injury to [the employee’s] ACL leading to instability to the knee hastening and accelerating the degenerative changes that he had already experienced.”
On December 4, 2008, an administrative conference was held on the employer’s NOID. In her order on discontinuance issued December 8, 2008, the compensation judge concluded in part that the employee’s current condition was not causally related to his July 2006 work injury, and on that basis she granted the discontinuance. The following day, December 9, 2008, the employee began working at a job as a cashier at Walmart, at which he earned about $8.25 an hour, working an average of about twenty-eight hours a week. He subsequently missed some work at this job as a result of his heart condition, his knee infection, and his underlying knee condition, there being no evidence as to the relative amount of time lost due to each.
By December 16, 2008, the employee’s infection was worsening again and necrotic, and Dr. Hughes recommended surgical irrigation, debridement, and removal of foreign debris. The following day, the employee underwent a preoperative evaluation by Dr. Molenaar, who approved of the surgery, acknowledging in his report the employee’s nonknee-related diagnoses of diabetes, stent-treated coronary artery disease, hypertension, hyperlipidemia, history of acid reflux, hypertriglyceridemia, hypercholesterolemia, depression, and nicotine dependency. The surgery was evidently performed, and the wound was wrapped in a vacuum dressing to assist in healing.
On December 31, 2008, the employee filed an objection to discontinuance, seeking reinstatement of his wage replacement benefits, together with a medical request seeking approval of a total right knee replacement as recommended by Dr. Hughes. The employer subsequently objected to the request, based on the report of Dr. Strand. In January and early February 2009, the employee’s wound showed signs of satisfactory healing, and on February 17, 2009, Dr. Molenaar recommended an assessment for chronic pain treatment, in hopes that the employee would eventually be able to actually clear his infection and move on to getting his right knee replacement. On February 19, 2009, the employee’s December 31, 2008, objection to discontinuance and his medical request of the same date were consolidated for hearing. As of March 10, 2009, the infection in the employee’s right knee was still chronic, with sizeable effusion.
On May 26, 2009, QRC Rutenbeck testified by deposition. He indicated in part that it was his understanding that the employee was restricted from all work for about five or six weeks after his April 10, 2008, arthroscopic surgery and was not released to return to work with sedentary restrictions until May 20, 2008. He testified that the employer’s claims representative, Mr. Rendina, was reluctant from the start to initiate job placement services until the employee’s functional abilities improved but that he did authorize vocational testing. Mr. Rutenbeck testified also that, although the employee was currently still working at his job at Walmart, it would not, in his opinion, be appropriate to terminate the employee’s rehabilitation services. He explained that his opinion was based on the possibility that additional surgery might be imminent and on a continuing question as to the suitability of the Walmart job, which entailed activity very arguably outside the employee’s sedentary restrictions.
The matter, initially set for hearing on March 10, 2009, eventually came on for hearing on June 16, 2009. Issues at hearing included the employee’s entitlement to ongoing wage loss benefits, including the issue of whether there has been a superseding intervening cause of the employee’s disability, and the employee’s entitlement to the recommended right knee replacement surgery, including the issues of whether any need for that surgery is causally related to his work injury and whether that surgery is reasonable and necessary. Evidence admitted at hearing included the testimony of the employee, in part that the infection in his right knee was “pretty much taken care of” by the date of the hearing.
By findings and order filed August 14, 2009, the compensation judge concluded in part that the employee’s work injury of July 20, 2006, was a substantial aggravating and contributing cause of the employee’s ongoing right knee problems and his need for a total knee replacement. The judge asserted in his memorandum that the employer’s arguments denying causation in the current proceeding were the same as those it had made in the prior hearing before him and that “[t]he court’s prior ruling is the law of the case and, under the principle of res judicata, cannot be re-litigated.” The judge went on to conclude that the employee was entitled to temporary total disability benefits from October 30, 2008, through January 2, 2009, and to temporary partial disability benefits ongoing from January 3, 2009, based on his underlying degenerative knee condition and torn ACL, both of which the judge found to be work related and treatment for which the judge found also compensable.
The judge concluded further, however, that the proposed total knee replacement, though causally related to the work injury, was not reasonable and necessary at the present time, in that a continuing infection in the knee made the procedure currently too dangerous. The judge found little evidence that the infection was substantially caused by the employee’s work injury or his arthroscopic surgery. He concluded instead that it was a result of the prolonged open wound on the employee’s knee, which in turn had occurred when the employee fell and scraped the knee due in no way to his underlying knee condition. Nor did the judge find that the infection in the knee was a superseding intervening cause of the employee’s current disability, the knee being subject also, in addition to the infection, to significant degeneration and a torn anterior cruciate ligament, both work related.
In addition to the employee’s infection, the judge found also that the employee was a smoker and had other serious medical conditions, including heart problems, diabetes, obesity, diabetic neuropathy, and degenerative arthritis. While finding the employee’s treatment for his underlying knee condition compensable, the judge found treatment for all unrelated conditions, including the infection in the right knee and these other maladies, not compensable. Upon all of these findings, the judge ordered the self-insured employer to pay to the employee temporary total disability benefits from October 30, 2008, through January 2, 2009, together with temporary partial disability benefits continuing from January 3, 2009. The judge further ordered the employer to pay the intervenor, Mayo Clinic, for all treatment that it had issued related to the employee’s underlying right knee condition. The judge denied, however, the employee’s claim for approval of total knee replacement surgery. The employer appeals from the judge’s finding that its defenses to causation are subject to principles of res judicata and from the judge’s awards of wage replacement and medical benefits, and the employee cross-appeals from the judge’s reliance on the opinion of Dr. Strand in denying the employee’s request for the surgery.
STANDARD OF REVIEW
In reviewing cases on appeal, 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.” Minn. Stat. § 176.421, subd. 1. 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.” 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, “[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 Foods 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, “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.” Id.
1. Res Judicata & Prejudice
At Finding 3, the compensation judge reported the following in reference to the prior hearing in this matter, held on January 4, 2008:
In a Findings and Order served and filed on March 3, 2008, the court determined that the right knee problems that the employee was having at the time of the hearing were causally related to the 2006 work injury and that the work injury was a substantial aggravating and contributing cause of the ongoing knee problems.
In his memorandum, the judge went on to explain that this
means that the employer is now responsible for the employee’s entire knee condition including the preexisting problems (except for the infection). The preexisting knee condition was not the result of a prior work injury and apportionment of liability is not allowed. The court’s prior ruling is the law of the case and, under the principle of res judicata, cannot be re-litigated in a subsequent proceeding.
The employer contends that the judge erred as a matter of law in this conclusion, in that the current litigation presented separate and distinct claims, issues, and defenses. The employer argues that its defenses in the current proceeding were based primarily on its assertion that the employee’s April 10, 2008, arthroscopic surgery intervened to cure and relieve the employee’s medial meniscus work injury. That defense, it argues, was clearly unlitigated at the first hearing, in that the April 10, 2008, surgery post-dated the first hearing. The employer argues further that a reading of the judge’s 2008 decision “highlights [the judge’s] belief that the arthroscopic surgery would relieve and cure the effects of the work-related injury, leading a reasonable person to believe that the aggravating cause is only temporary in nature.” This inference, the employer argues, is contrary to implications in the memorandum of the judge’s 2009 decision, that the injury is permanent - - permanency being also, the employer argues, an issue unlitigated at the first hearing. Finally, the employer argues that the judge’s conclusion in the decision here at issue was legally erroneous for being prejudicial, in that it presumed, contrary to case law precedent, that any permanent aggravation of a pre-existing condition caused by the work injury necessarily renders the work injury a substantial cause of the condition itself and its treatment. We conclude that, while it was inaccurate for the judge to assert his conclusion under the doctrine of res judicata, the judge’s findings and ultimate conclusion are supported by substantial evidence and are not prejudicial.
A decision as to an employee’s entitlement to temporary wage replacement and/or medical benefits for a particular period of time is not res judicata with regard to his or her entitlement to such benefits for a different period of time and/or treatment. Evidence and defenses will differ with each new period of wage replacement and each new requested treatment, as here they do. The three reports of Dr. Strand upon which the employer based its current defense - - made in December 2006, December 2007, and September 2008 - - did repeatedly allege that the employee’s 2006 work injury was a temporary one that had fully resolved, most likely within six weeks after the injury - - notwithstanding the compensation judge’s March 2008 finding that the injury was still a substantial cause of the employee’s “ongoing” knee problems at that time. However, other defenses to the employee’s claim that his work injury has continued to be “ongoing,” during subsequent benefit periods and requiring different treatment, have also been asserted. Hence, the doctrine of res judicata has no application here, since neither the specific issues of the 2008 proceeding nor the doctrine itself was at issue at the 2009 proceeding.
That said, however, and notwithstanding the judge’s brief reference to the doctrine, in a single sentence, in his memorandum, we find nothing in any of the compensation judge’s August 2009 findings or orders to suggest that the judge’s conclusions in this recent proceeding, regarding total knee replacement surgery and wage replacement continuing since October 30, 2008, were dictated by any res judicata effect of his March 2008 conclusions in the previous proceeding, regarding arthroscopic surgery, rehabilitation benefits, and wage replacement prior to that time.
At Finding 10 the compensation judge concluded that the employee’s July 2006 work injury was a “substantial aggravating and contributing” cause of the employee’s ongoing right knee problems and need for total knee replacement, and at Findings 14 and 15 he concluded that the employee was therefore entitled to temporary total and temporary partial disability benefits. In addition to finding the judge’s decision erroneous as a matter of law, as addressed above, the employer contends that these conclusions of the judge as to causation are unsupported by substantial evidence. The employer argues that the employee’s work-related injury of July 2006 was completely resolved with his April 2008 arthroscopic surgery and that the contrary opinions of Dr. Hughes, on which the judge relied, were “flawed, inaccurate and deficient,” contrary to those of Dr. Strand. We are not persuaded.
The employer contends that the employee’s work injury was completely and permanently resolved with the April 2008 repair of his right medial meniscus tear, arguing that the torn ACL evident during the arthroscopy was a condition pre-existing the work injury. We note, however, that the only abnormality reported in the most recent pre-injury reference to the employee’s ACL, in Dr. Hughes’ December 2, 2005, arthroscopic operative report, is only some fraying that was completely resolved by simple debridement, whereas the most recent post-injury reference, in Dr. Hughes’ April 10, 2008, arthroscopic operative report, notes that “the ACL was observed to be partially torn.” Moreover, in his November 20, 2008, narrative report to the employee’s attorney, Dr. Hughes expressly opined that this condition was directly related causally to the employee’s July 20, 2006, work injury. The employer has argued that the opinions of Dr. Hughes have failed to take into consideration the doctor’s own prior operative reports, which the employer argues showed significant preexisting degenerative changes in the employee’s knee, including ACL involvement. The record documents, however, a clear change in the ACL, from frayed pre-injury to torn post-injury, and we find due consideration for that record in Dr. Hughes’ opinion that the torn ACL has led to an instability that has in turn been “hastening and accelerating the degenerative changes that [the employee] had already experienced.” The employer argues that Dr. Hughes’ opinions fail also, contrary to the opinions of Dr. Strand, to take into consideration, as possible causes of the employee’s current condition, the employee’s morbid obesity, his history of smoking, his multiple surgical interventions on the left knee, his diabetic joint neuropathy, his ten-year history of significant joint degeneration and arthritis, and his ten prior right knee surgical interventions. Dr. Hughes addressed these considerations also in the November 20, 2008, narrative report in which he reiterated his recommendation of total knee surgery. We conclude that it was not unreasonable for the compensation judge to rely on the opinion of Dr. Hughes and that the judge’s conclusion on the issue of causation is not therefore or otherwise unsupported by substantial evidence. See Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985) (a trier of fact's choice between experts whose testimony conflicts is usually upheld unless the facts assumed by the expert in rendering his opinion are not supported by the evidence); Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.
3. Denial of Surgery
At Finding 7, the compensation judge described the infection in the employee’s right knee for which the employee had been treated since August 2008, concluding that “[t]here is little evidence that the infection has been cured.” At Finding 11, the judge went on to conclude that the total knee replacement requested by the employee - - while causally related to the work injury, as found in Finding 10 - - was not currently reasonable and necessary, because “[t]he chronic infection in the right knee makes the procedure too dangerous at the present time.” In his memorandum, the compensation judge explained that he was “persuaded by the opinion of Dr. Strand” in reaching this conclusion. The employee contends that the judge’s conclusion is clearly erroneous and unsupported by substantial evidence, in that the report of Dr. Strand, upon which the judge relied, had neither the necessary evidentiary support nor the requisite factual foundation to be relied upon, leaving Dr. Hughes’s opinion recommending the surgery uncontroverted. We are not persuaded.
In his brief, the employee’s only argument as to the sufficiency of evidentiary support for Dr. Strand’s opinion is that the doctor’s opinion was based on a conclusion that the employee’s work injury was only temporary and has already resolved, which the employee contends is contrary to the law of the case. As the employee observes, this conclusion by Dr. Strand as to the duration of the employee’s injury constitutes an opinion that the employee’s work injury is no longer causally related to his current condition. Without explanation, however, the employee appears to ignore the fact that the judge concluded expressly at Finding 10 - - in the employee’s own favor - - that the employee’s work injury was causally related to his need for knee replacement surgery. The judge’s denial of knee replacement surgery was based not on a conclusion that such surgery was not causally related to the work injury but on a conclusion that such surgery was not reasonable and necessary “at the present time.” Dr. Strand’s opinion as to causation is not relevant to the issue of whether the requested surgery is currently reasonable and necessary in light of the employee’s chronic infection. Nor do we find Dr. Strand’s opinion insufficient on foundational grounds to have been relied on to the extent that it was. In that the employee has not addressed, either foundationally or in terms of substantial evidence, the actual basis for the judge’s denial of his request for total knee replacement, we will not reverse the judge’s denial of the surgery, which we find reasonably supported on its expressed basis in the medical opinion of Dr. Strand. See Nord, 360 N.W.2d at 342-43, 37 W.C.D. at 372-73; Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.