The employer and insurer appeal from the compensation judge’s determination that the employee’s claim for medical expenses was not barred by res judicata or collateral estoppel.  They further appeal from the finding that pool therapy was reasonable and necessary, and from the finding that the June 3, 2005, work injury aggravated or accelerated the degenerative changes at the employee’s SI joints and was a substantial contributing factor in the claimed treatment expenses.  We affirm.

The employee, Sheri L. Meyers, worked in the receiving department for the employer, a supplier of electrical parts to contractors.  On June 3, 2005, while moving a heavy box from a forklift to a floor-level shelf, the employee felt a “pop” in her low back and experienced an onset of low back pain below the belt line.  She first sought treatment at the Park Nicollet Clinic on June 7, 2005, where she was diagnosed with a lumbar strain.  She was given moderate work restrictions, a prescription for Flexeril and Vicodin, and was advised to return in one week for a recheck.

A first report of injury was filed with the Department of Labor and Industry on June 9, 2005, describing the employee’s injury as a lumbar strain/sprain or a sacral strain.

The employee tried chiropractic treatment over the next week but experienced no improvement.  On June 14, 2005, she returned to the Park Nicollet Clinic, where she saw Dr. Constance Pries.  She continued to have low back pain, primarily into the left buttock and left thigh.  Dr. Pries diagnosed bilateral acute L5 radiculopathy, took the employee off work, and recommended an MRI scan.  The employee was prescribed Percocet for pain management.  The MRI, done on June 22, showed disc desiccation with minimal diffuse bulges and mildly degenerative disc disease at L2‑3, a normal spine at L3-4, and mild desiccation and minimal bulging without herniation at L5-S1.

On June 23, the employer and insurer accepted liability for the June 3, 2005, work injury and began paying temporary total disability benefits.

On June 24, 2005, the employee returned to the Park Nicollet clinic and saw Dr. John Dunne.  Dr. Dunne diagnosed “low back pain, mild ligamentous problems” and prescribed physical therapy, home exercises and medication.  The employee then returned to Dr. Pries on July 1, 2005 reporting no improvement following the physical therapy.  Dr. Pries prescribed a trial use of a TENS unit and released the employee to part-time light-duty work, which the employee attempted but found too painful.  On July 13, the employee again returned to Dr. Pries.  Dr. Pries thought the employee might have a left SI strain, and recommended an SI joint injection.

The employee had the injection on July 18, 2005.  She went to urgent care on July 24 and 25, where she reported that after the injection, the pain had gotten worse and she had nausea and vomiting and pain down to the left leg.  Dr. Pries saw the employee again on July 29, 2005, when she reported she had not improved and was unable to work due to pain.  Dr. Pries recommended a CT scan of the pelvis to visualize the SI joints.

The scan, performed on August 2, 2005, revealed sclerotic changes on both SI joints, right greater than left, without associated frank destructive changes.  There was also a chip fracture of the anterior aspect of the sacral side of the right SI joint.  The employee next returned to Dr. Pries on August 5.  The doctor concluded that the degenerative changes shown at the employee’s SI joints in the pelvic CT scan were “longstanding over many years.”  The employee’s physical exam was benign and Dr. Pries authorized the employee to return to full-time, unrestricted work.

The employee sought treatment from Dr. Anne Brutlag, in Park Nicollet’s physical medicine and rehabilitation department beginning on September 21, 2005.  On that date, the employee’s pain was in the low back, right sacroiliac, left buttock, and right thigh.  Dr. Brutlag diagnosed “low back pain, sacroiliac mechanic dysfunction, possible chip fracture right SI joint.”  She kept the employee off work, continued her medications, and recommended physical therapy.

In October 2005, Dr. Brutlag noted that standard physical therapy had not been helpful.  She prescribed aquatic therapy instruction at Courage Center.  The employee started the pool therapy in November.  In December 2005, Dr. Brutlag released her to return to work with restrictions at two hours per day.  The employer provided the employee with work within her restrictions.

On December 28, 2005, the employee was examined for the employer and insurer by Dr. David Boxall.  Dr. Boxall opined that the June 3, 2005, work injury had been a mild strain of the low back from which maximum medical improvement was reached by July 1, 2005.  He found no evidence of an SI joint injury.  In a subsequent report dated April 4, 2006, he concluded that there was no objective basis to restrict the employee’s work.  He further opined that the employee had “augmented” her symptoms due to functional overlay and an apparent dependence on prescription narcotics.

In January 2006, Dr. Brutlag recommended that the employee increase her work hours gradually to six hours per day, three days per week.  She extended the employee’s pool therapy at Courage Center.

An MRI scan on March 7, 2006 showed no significant change from the earlier scan done on June 22, 2005.  The employee returned to Dr. Brutlag the next day and complained of low back, right buttock and leg pain, with her symptoms having escalated over the past two weeks.  Dr. Brutlag treated the employee by sacroiliac joint injection, recommended further aquatic therapy, and continued the employee’s use of Percocet.

On April 26, 2006, the employer and insurer filed a Notice of Intent to Discontinue temporary partial disability benefits based on the opinion of Dr. Boxall.  Following an administrative hearing on discontinuance pursuant to Minn. Stat. § 176.239, a compensation judge denied discontinuance, concluding that the employee’s symptoms were related to an aggravation of her pre-existing SI joint condition as a result of the work injury.  The employer and insurer requested a formal hearing by a Petition to Discontinue, filed on July 14, 2006.

On August 25, 2006, a hearing on the discontinuance was held before Compensation Judge Harold Schultz at the Office of Administrative Hearings.  In his findings and order of September 14, 2006, Judge Schultz found that the lumbosacral strain/sprain sustained in the June 3, 2005, work injury had resolved.  He further found that the employer and insurer had shown by a preponderance of the evidence presented that the June 3, 2005, injury was not a substantial contributing factor in the employee’s wage loss and need for medical treatment as of the date of hearing.  However, the compensation judge did not make any finding as to whether the injury had or had not aggravated the employee’s SI joint condition, finding instead that “it is unclear and it cannot be determined from the current record if the employee sustained more than a lumbosacral strain/sprain on June 3, 2005.”  In his memorandum, the judge noted that he “does not accept Dr. Boxall’s opinion that the employee sustained only a low back strain on June 3, 2005,” and that the employee was “free to bring a claim . . . for any other benefits, if there is convincing evidence which supports her current condition as being related to the effects of the personal injury.”

The employee appealed from the discontinuance granted by Judge Schultz.  No appeal was taken by either party from the finding that it could not be determined whether the employee had sustained any further injury on June 3, 2005, other than a lumbosacral strain/sprain.  This court affirmed the discontinuance.^[1]

On September 13, 2006, Dr. Brutlag saw the employee and opined that the employee had been “well instructed in an independent program by the aquatic physical therapist at Courage Center and is capable of and willing to do the program independently.”  She noted that the employee had recently been doing the pool therapy independently in her apartment’s outdoor pool until it closed for the season.  She recommended that the employee be provided with a health club membership for access to a pool during the winter months.

The employee filed a claim petition on January 3, 2007, seeking temporary partial disability since the August 26, 2006, hearing before Judge Schultz and reimbursement for recent medical treatment provided by Dr. Brutlag.  An amendment to the claim petition on March 8, 2007, sought payment for pool therapy.  The employer and insurer denied liability in their answer.

On January 10, 2007, the employee told Dr. Brutlag that she was having more difficulty managing her symptoms and that her Percocet was not providing adequate control of her pain.  The doctor gave her a prescription for Oxycontin to be taken twice daily, and advised her that she might also take up to six Percocet per day as needed for “breakthrough pain.”  She also recommended a trial of right-sided SI injections.  The employee underwent three such injections in April and May, 2007, noting a brief relief of symptoms after each.

The employee continued to treat with Dr. Brutlag who has seen her every few months for monitoring of her prescriptions and status.  On each occasion Dr. Brutlag continued to recommend therapeutic aquatic exercises.

In a narrative report written to the employee’s attorney on August 8, 2007, Dr. Brutlag offered the opinion that the 2005 work injury was a substantial contributing factor in rendering the employee’s pre-existing SI joint dysfunction symptomatic, and in the need for work restrictions and ongoing medical treatment.

The employee was evaluated for the employer and insurer by Dr. Richard Hadley on November 8, 2007.  Dr. Hadley disagreed with Dr. Brutlag.  While he acknowledged that the employee had significant degenerative arthritis of the sacroiliac joints, he offered the opinion that the injury on June 3, 2005, was only a lumbar strain and did not contribute to the employee’s SI condition.  In his view, the employee’s current symptoms were the result of chronic low back pain of unknown etiology.  He did not think that the employee needed any restrictions due to the work injury, although he deemed moderate lifting and carrying restrictions appropriate due to the employee’s pre-existing sacroiliac joint condition.  In his view, medical treatment rendered to October, 2005, was appropriate, while none of the treatment thereafter was reasonable or necessary.

In December 2007, the employee entered into a full, final and complete stipulation for settlement, with the sole exception of future reasonable and necessary medical treatment.  Among the possible claims foreclosed was any future claim for health club memberships.  The parties all specifically reserved their various claims and defenses.

The employee filed a medical request on October 6, 2008, seeking reimbursement for out of pocket prescription expenses, ongoing prescription costs, costs of treatment with Dr. Brutlag, and approval of pool therapy.  In a medical response filed on October 10, 2008, the employer and insurer denied the employee required any medical treatment, based on the opinion of Dr. Hadley; they further asserted that the employee’s use of narcotic prescription medications was not only unrelated to the work injury but was unwarranted and excessive.

As the medical request was being certified, the employer and insurer agreed to pay for office visits with Dr. Brutlag.  The remaining issues presented by the medical request were considered at an administrative conference pursuant to Minn. Stat. § 176.106, on November 24, 2008.  After reviewing the matter, the arbitrator at the conference concluded that the employee’s claims were precluded as a matter of res judicata by Compensation Judge Schultz’s 2006 Findings and Order.  By a Decision and Order Pursuant to Minn. Stat. § 176.106, served and filed on December 2, 2008, the arbitrator denied the employee’s medical request.

The employee filed a request for formal hearing.  Prior to the hearing, the employer and insurer filed a motion to dismiss the matter as res judicata.  The motion was denied, and the matter went on to hearing before a compensation judge of the Office of Administrative Hearings on February 18, 2009.  Following the hearing, the judge concluded that the Findings and Order of Judge Schultz did not preclude litigation of the issue of whether the employee had sustained a work-related aggravation to her pre-existing SI joint condition, or of claims for medical treatment related to such a condition.  The compensation judge specifically adopted the opinion of Dr. Brutlag that the June 3, 2005, work injury had aggravated or accelerated the degenerative changes in the employee’s SI joints.  She further found that the work injury was a substantial contributing factor in the prescribing of narcotic medications, and to Dr. Brutlag’s recommendations for ongoing pool therapy.  However, while she found pool therapy to be reasonable and necessary, she found that the employee’s use of narcotic pain medications was not reasonable or necessary.  The employer and insurer appeal.

The employer and insurer appeal from the compensation judge’s conclusion that Judge Schultz’s 2006 findings and order were not res judicata with respect to the issues before her.  Res judicata is a doctrine bringing finality to legal proceedings in which “a final judgment on the merits bars a second suit for the same claim” by the same parties.  Kaiser v. Northern States Power Co., 353 N.W.2d 899, 902 (Minn. 1984).  Principles of res judicata are applicable in workers’ compensation proceedings.  See, e.g., Alexander v. Kenneth R. LaLonde Enters., 288 N.W.2d 18, 31 W.C.D. 407 (Minn. 1980).  However, res judicata applies in workers’ compensation cases only with respect to issues specifically litigated and decided in prior proceedings.  See, e.g., Fischer v. Saga Corp. , 498 N.W.2d 449, 450, 48 W.C.D. 368, 369 (Minn. 1993); see also Westendorf v. Campbell Soup Co., 243 N.W.2d 157, 158, 28 W.C.D. 460, 460 (Minn. 1976).

The employer and insurer argue that Judge Schultz’s findings must be interpreted as implicitly including a determination that the employee’s SI joint condition was either unrelated to the work injury or that any work related aggravation of her SI joint condition had resolved by the date of the August 25, 2006, hearing.  They contend that such an interpretation is warranted by the “plain language” of the judge’s findings, and that the compensation judge’s contrary interpretation of the prior findings rested only on an erroneously “perceived” ambiguity in the language of the findings.

To interpret the 2006 findings and order, we must look at the precise words used in the relevant findings, numbers 36, 37, and 39.  Where there is an ambiguity, we will also look at any language in the judge’s memorandum that clarifies the intent of the findings.

The employer and insurer argue that Judge Schultz specifically found that the effects of the employee’s 2005 work injury were temporary and had fully resolved by the date of the August 25, 2006, hearing.  Accordingly, they contend, the employee was barred from asserting that any subsequent disability and medical treatment was related to that injury.  We believe this contention is based on a mischaracterization of Judge Schultz’s findings.  In finding 37, the only finding expressly dealing with the resolution of some part of the work injury, the compensation judge found only that a lumbosacral strain/sprain had resolved.  Clearly, finding 37 does not constitute a final determination regarding the status of an aggravation of a dysfunction of the SI joints.

The employer and insurer counter that findings 36 and 39, if read together, demonstrate that the judge’s finding of a temporary or resolved injury implicitly includes other conditions, such as the employee’s SI joint dysfunction now at issue.  In finding 39, the judge found, in essence, that the preponderance of the evidence at hearing failed to support a causal link between the employee’s injury and her current disability and medical treatment.  They contend that finding 36, in which the judge found the evidence unclear as to other potential effects of the work injury, simply memorializes the idea that the employee had “not carried her burden of proof” to show any other condition as a basis for a determination that the ongoing disability or medical treatment was related to the work injury.

This argument would be more persuasive if the compensation judge’s memorandum had not clearly indicated that he had rejected Dr. Boxall’s view that the work injury had resulted solely in a lumbosacral strain/sprain.  In addition, the judge’s memorandum specifically states that the intended effect of his findings was to leave the employee free to bring a later claim based on “convincing evidence which supports her current condition as being related to the effects of the personal injury.”  In light of this clear expression of the judge’s reasoning and intentions, we must reject the contradictory view that the judge implicitly meant to render an implicit determination about any condition beyond the lumbosacral strain/sprain component of the employee’s injury.

Finally, the employer and insurer argue that for Judge Schultz to leave unresolved the possibility and effects of other conditions potentially caused by the work injury would have been contrary to the law and evidence before him, in light of an employee’s burden of proof on all issues related to eligibility for benefits.  Thus, they argue, even if the judge’s findings could reasonably bear the interpretation that he intended to leave those issues open, this court should nonetheless give them a res judicata or collateral estoppel effect.  We do not, however, reach the question whether Judge Schultz erred as a matter of law or fact in failing to make a finding on the causation or status of the employee’s alleged SI joint condition.  Any argument that the judge committed errors of law or fact in his 2006 findings should have been raised in an appeal from the 2006 order.  The sole issue before us is thus one of the interpretation and import of those findings, not their propriety.  Having reviewed the express language of the judge’s findings as well as the judge’s memorandum, we conclude that the issue of causation for an SI joint aggravation was not determined in the former proceeding.

In the absence of a final determination of the issue of whether the employee’s 2005 work injury aggravated her SI joint condition, res judicata or collateral estoppel here did not foreclose determination of that issue at the subsequent hearing below.  Cf., e.g., Thompson v. J & L Steel Erectors, 68 W.C.D. 235 (W.C.C.A. 2008).

The employer and insurer point out that pool therapy was instituted in late 2005 and was specifically litigated during the 2006 hearing.  They contend that, regardless whether the 2006 findings were res judicata with respect to the claimed aggravation of the employee’s SI joint dysfunction, the issue of pool therapy was at least foreclosed by the judge’s finding that the preponderance of the evidence failed to establish a causal link between the work injury and current medical treatment.  We agree that the question of pool therapy was foreclosed through the date of hearing.  However, findings involving the need for, or the reasonableness or effectiveness of medical treatment are generally not deemed res judicata for later periods.  Cf., e.g., Gullickson v. Commonwealth Elec. Co., slip op. (W.C.C.A. Nov. 28, 1989) (medical restrictions determined for a prior period were not res judicata for a subsequent period).

The compensation judge found that the 2005 work injury had aggravated or accelerated the pre-existing degenerative changes in the employee’s SI joints.  She further accepted Dr. Brutlag’s recommendations for ongoing therapeutic pool exercises as reasonable and necessary.  The employer and insurer contend that substantial evidence fails to support these findings.  They rely on the medical opinions expressed by Drs. Hadley and Boxall, who held the view that the employee’s SI joint condition had been unaffected by the work injury.

In reaching her findings, the compensation judge expressly accepted the contrary medical opinion of treating physician Dr. Brutlag, who explained her views in deposition testimony.  The judge’s findings on both issues were further supported by the employee’s testimony and by the medical records.  Among the factors supporting Dr. Brutlag’s view were the absence of significant symptoms prior to the work injury in contrast with those subsequent to it; the presence of a chip fracture at the SI joint which suggested a possible traumatic injury; and the fact that diagnostic injections made at the SI joint in the spring of 2007 provided short-term relief of the employee’s symptoms.  As to the recommendation for pool therapy, there were progress notes from Courage Center showing improvement.  The treating physician’s chart notes also chronicle increases and decreases in the employee’s pain and level of function related to the extent to which she was or was not able to continue with the exercises.

Appellants argue that it was improper for the compensation judge to reject that part of Dr. Hadley’s opinion which denied that the work injury aggravated the employee’s SI joint condition, since the compensation judge had accepted the part of his opinion which rejected the use of narcotic medications as reasonable and necessary treatment.  They cite Tomford v. Mark’s Welding, slip op. (W.C.C.A. Dec. 6, 2006), contending that case stands for the proposition that a compensation judge may not accept portions of a medical report while rejecting other portions.  We disagree with their interpretation of that case, which reversed and remanded certain findings merely because the facts the judge found to support one finding were irreconcilably inconsistent with those necessary to support the other.  As that case itself noted, a judge is free to adopt part of a witness’ testimony, while rejecting other parts, so long as the selection does not result in a set of conclusions which are internally inconsistent.  See, e.g., City of Minnetonka v. Carlson, 298 N.W.2d 763 (Minn. 1980).

With respect to the pool therapy,^[2] the appellants also contend that Dr. Brutlag failed to document the utility of the employee’s pool exercise program, or to set out a specific treatment plan for those exercises.  We note, however, that the employee completed training at Courage Center to instruct her in the techniques and types of exercises appropriate for her condition and symptoms, and that she had demonstrated an ability to manage the program independently prior to her discharge from therapy there.  In addition, although Dr. Brutlag did not provide detailed instructions as to the specific exercises to perform, her chart notes do contain specific recommendations as to the number of times per week that the exercises should be done.  In any event, this was not a case involving the application of medical treatment parameters, and the degree of supervision over the program provided by Dr. Brutlag was a matter which went to the weight, rather than to the admissibility, of Dr. Brutlag’s treatment recommendations.

A compensation judge’s choice between conflicting medical opinions is generally upheld unless the facts assumed by the expert in rendering his opinion are not supported by the evidence.  Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).  We see no foundational defect with Dr. Brutlag’s opinion, and no basis for disregarding the compensation judge’s choice of expert opinion.  There is substantial evidence present to support the judge’s findings, and we affirm.