The employee appeals from various findings supportive of the compensation judge's denial of permanent partial and permanent total disability compensation.^[1]  We reverse and remand for further findings and order.

On November 29, 2000, Dawn Peterson sustained a work-related injury to her right upper extremity while assisting a resident in the course of her employment as an activities leader with Benedictine Health Center [the employer].  Ms. Peterson [the employee] was forty-nine years old on that date and was earning a weekly wage of $280.00.  The self-insured employer admitted liability and commenced payment of benefits.  Eventually, following a hearing on February 18, 2003, and by findings and order of Compensation Judge James Cannon filed April 3, 2003, the employee was determined to have developed a right upper extremity reflex sympathetic dystrophy [RSD] consequent to her November 2000 work injury, in accordance with the medical diagnoses of four different physicians.  This conclusion was not appealed.  In that same April 3, 2003, decision, Judge Cannon also found, however, that the employee had 0% permanent partial disability as a result of her work-related right upper extremity injury, notwithstanding her claim for a 15% whole-body rating related to her diagnosis of mild RSD under Minnesota Rule 5223.0410, subpart 7A, and for an additional 3% rating related to carpal tunnel syndrome under Minnesota Rule 5223.0470, subpart 2B(3).  The judge denied the RSD-related claim because the employee did not prove that she was subject to at least five of the eight factors listed in Minnesota Rule 5223.0410, subpart 7, as required under that rule for a permanent partial disability rating, and he denied the carpal tunnel-related claim on grounds that the employee had not had a repeat EMG as required under subpart 2B(3) of Rule 5223.0470.  Finally, Judge Cannon concluded also that the employee was not permanently and totally disabled, explaining in his memorandum that, even had she been able to meet the 17% permanent partial disability threshold required for permanent total disability status under Minnesota Statutes § 176.101, subdivision 5(2)(a) - which the judge found unmet - the employee had not proven that she was permanently disabled and unemployable from either a medical or a vocational point of view.

About seven months later, on November 17, 2003, the employee filed a claim petition, realleging entitlement to various benefits, including permanent total disability benefits and compensation for permanent partial disability of 38% of her whole body - 15% related to her right arm, 3% related to carpal tunnel syndrome, and 20% related to depression.  The claim was made consequent to work injuries on November 29, 2000, in the nature of mild RSD in the right arm, carpal tunnel syndrome with surgical release in the right wrist and hand, ligament tears in the right wrist, and “[c]hronic diffuse myalgias and paresthes[]ias and other diffuse symptomatology due to a chronic anxiety state.”  The employer denied the claims on November 26, 2003, and on February 19, 2004, the employee amended her claim petition to allege entitlement also to an award of penalties, on grounds that the employer had refused payment for certain treatment expenses in violation of Judge Cannon’s order.

On March 26, 2004, the employee was examined for the employer by orthopedic surgeon Dr. Paul Dworak,^[2] who diagnosed the following: (1) diffuse subjective symptoms of multiple arthralgias affecting both right and left upper and lower extremities, not substantiated by any objective physical findings; (2) multiple somatic complaints of pain and symptoms, presumed to be aggravated by [the employee’s] underlying psychiatric disorder; (3) status post right carpal tunnel endoscopic release with no evidence of any recurrent median nerve dysfunction; (4) history of depression; (5) history of anxiety; and (6) history of panic attacks.  Dr. Dworak indicated further that, while he respected Judge Cannon’s acceptance of an RSD diagnosis, “quite honestly, I see no orthopedic evidence whatsoever of reflex sympathetic dystrophy.”  He indicated that, from an orthopedic standpoint, he would place no restrictions on the employee’s work activities and that it was his opinion that she had been fully capable of employment from and after November 29, 2000.  He opined further that the employee was no longer benefitting from any medical treatment barring psychiatric evaluation, and he rated her upper extremity-related permanent partial disability at 0% of her whole body.

On January 28, 2005, occupational medicine specialist Dr. Jed Downs, who had been treating the employee since February of 2001, issued a report to the employee’s attorney in answer to various queries.  In his report, Dr. Downs diagnosed various conditions in the employee, including RSD, chronic pain, fibromyalgia, back symptoms, psychiatric conditions, and pain down the legs.  Based on these diagnoses but without specifying whole-body percentages, Dr. Downs indicated that he would rate the employee’s permanent partial disability under any of several different specified subparts of the Minnesota Rules, depending on which of the employee’s fluctuating conditions happened to be currently symptomatic and to what extent.  Dr. Downs indicated further that he found the employee’s November 2000 work injury to be a substantial contributing factor in “any or all” of the employee’s diagnoses, and he opined that the employee’s medical care had been reasonable and necessary.  Finally, it was Dr. Downs’ opinion that the employee was not capable of returning to work even on a part-time basis, “that her overall condition, does more likely than not, permanently and totally disable her from gainful employment.”

In a subsequent deposition on March 28, 2005, Dr. Downs testified that he had rated the employee’s permanent partial disability for her right upper extremity RSD under Minnesota Rule 5223.0400, subparts 6A and 6B, for mild and moderate conditions respectively, depending on when the employee was examined.  He explained that, “[i]n the . . . six to seven weeks after she has an epidural steroid injection, it’s probably mild.  In the three to four weeks before she gets her next epidural steroid injection, it’s probably moderate.”  Using the fifty-seven percent multiplier found in Minnesota Rule 5223.0540, subparts 1.F., Dr. Downs rated the employee’s whole body impairment related to her right upper extremity at 14.25% if mild and at 28.5% if moderate.

On April 19, 2005, Dr. Dworak testified by deposition in response to Dr. Downs’ testimony and the reports and testimony of various other doctors, essentially confirming his conclusions of March 26, 2004, and clearly questioning the credibility of the employee’s complaints.

The employee’s claims came on for hearing before Compensation Judge Gregory A. Bonovetz on April 26, 2005.  Issues at hearing included (1) whether, as a result of her November 2000 upper extremity work injury, and notwithstanding Judge Cannon’s unappealed finding of 0% permanent partial disability on April 3, 2003, the employee had suffered any permanent partial disability to her right upper extremity and if so to what extent and (2) whether the employee had been permanently totally disabled since April 4, 2003, as a result of her November 2000 work injury.  By findings and order filed June 30, 2005, Judge Bonovetz found that “[s]ince the persistent presence of at least five of [eight rule-specified] conditions is required for a permanent partial disability rating for reflex sympathetic dystrophy and since the employee does not exhibit at least five conditions, by operation of rule the employee has sustained no permanent partial disability to the right upper extremity as a result of reflex sympathetic dystrophy.”  The judge found also that, “[u]nder the terms of the Minnesota Workers’ Compensation Act,” the employee had not been permanently totally disabled since April 4, 2003.  The judge concluded his accompanying memorandum with the following explanation of his decision not to award permanent total disability benefits:

The employee asserts on appeal that the compensation judge erred as a matter of law in declining to award permanent partial disability for her admitted RSD condition.  Citing this court’s decision in Stone v. Harold Chevrolet, the employee argues that the requirement in Minnesota Rule 5223.0410, subpart 7, that five of eight criteria be met for payment of permanency benefits for RSD, is invalid in light of the statutory requirement in Minnesota Statute § 176.021, subd. 3, that benefits are due for “functional loss of use or impairment of function, permanent in nature.”  See Stone v. Harold Chevrolet, 65 W.C.D. 102, 110 (W.C.C.A. 2004); Minn. Stat. § 176.021, subd. 3.  The Stone conclusion, she contends, renders benefits dependent only on the severity of the RSD condition, not on whether that condition meets any arbitrary number of criteria.  See Stone, 65 W.C.D. at 111-12.  Here, the employee argues, because there is no dispute that the employee does in fact have RSD in her right upper extremity, the issue of the employee’s entitlement to permanency benefits related to that condition must be reversed and remanded to the judge for further findings and an award dependent only on the severity of the condition, without consideration of whether she has met the diagnostic criteria of the rule.  The respondent employer argues that, while Judge Bonovetz did base his denial of permanent partial disability benefits on the conditions set forth in the rule, the evidence as a whole, including the objective medical evidence and the employee’s testimony, does not support a finding of a permanent functional loss of use or impairment of function.  Therefore, the employer argues, despite the Stone decision, a rating of higher than 0% is not appropriate and Judge Bonovetz’s decision on this issue should be affirmed on the facts.  We disagree and remand the issue to the compensation judge for further findings, concluding, in keeping with Stone, that, “[w]hen a diagnosis of RSD is established,” as it is here, “the compensation judge should determine the extent of permanent partial disability by applying” the rule.  Stone, 65 W.C.D. at 111.

In Stone, this court implied that, while perhaps useful in evaluating a contested diagnosis of RSD in the lower extremity, the eight factors identified in the first paragraph of Minnesota Rule 5223.0430, subpart 7, do not determine an injured employee’s entitlement to permanent partial disability benefits where the employee’s diagnosis is definitely established.  See generally Stone, 65 W.C.D. 102.  By analogy, this conclusion applies also in Minnesota Rule 5223.0410, subpart 7, which pertains to RSD in the upper rather than lower extremity and is otherwise identical.  Permanency benefits for RSD must be based on the severity of the employee’s permanent functional loss of use or impairment of function.  Id.  In the present case, Judge Bonovetz expressly based his denial of benefits not on the severity of the employee’s functional loss of use or impairment of function but on the employee’s failure to prove that she satisfied five of the eight factors specified in the diagnostic part of Rule 5223.0410, subpart 7.  Nor was the issue of the severity of the employee’s functional loss or impairment of function ever even addressed, much less made basic.  We therefore remand the issue to the compensation judge for a finding on the severity of the employee’s functional impairment and an appropriate rating under the schedule.

To the extent that it may have been implicit in either of the parties’ arguments here on appeal, we would acknowledge here in conclusion on this issue that, although not expressly raised on appeal, the issue of the res judicata effect of Judge Cannon’s decision was raised at the hearing below.  Res judicata, or “claim preclusion,” is essentially a finality doctrine in which “a final judgment on the merits bars a second suit for the same claim by parties or their privies.”  Kaiser v. Northern States Power Co., 353 N.W.2d 899, 902, (Minn. 1984).  Res judicata does not preclude litigation of issues that were not specifically decided in a prior proceeding.  See, e.g., Fischer v. Saga Corp., 498 N.W.2d 449, 48 W.C.D. 368 (Minn. 1993); Westendorf v. Campbell Soup Co., 243 N.W.2d 157, 28 W.C.D. 460 (Minn. 1976).  Determining exactly what issues were litigated in any given proceeding can be problematic.  In his findings and order, Judge Cannon did not specifically identify permanent partial disability as an issue before him for determination, although it was certainly incidental to the employee’s claim for permanent total disability benefits, and the judge did issue a finding regarding it.  Moreover, while finding that the employee had developed RSD as a result of her work injury, the judge did not address whether, as a result of that condition, the employee had actually suffered a functional loss of use or impairment of function.  The judge explained in his memorandum that he did not award permanent partial disability benefits because the employee did not have five of the eight conditions listed in Minnesota Rule 5223.0410, subp. 7.  Similarly, Judge Bonovetz denied the employee’s claim for permanent partial disability benefits by operation of rule and not on the severity of the employee’s functional loss of use or impairment of function.  Under the particular circumstances presented here, where the underlying issue of the severity of the employee’s functional impairment was never litigated, we believe that the employee’s claim for permanent partial disability should be allowed to proceed on the merits.  Cf. Johnson v. Consolidated Freightways, Inc., 420 N.W.2d 608, 613-14 (Minn. 1988) (res judicata is not to be applied rigidly; “[a]s a flexible doctrine, the focus is on whether its application would work an injustice on the party against whom estoppel is urged”) (citations omitted).

At Finding 9, Judge Bonovetz concluded that “[u]nder the terms of the Minnesota Workers’ Compensation Act the employee has not been permanently totally disabled since April 4, 2003.”  In his memorandum, the judge clearly indicates that his denial of permanent total disability benefits was based on the employee’s failure to prove that she was subject to the minimum amount of permanent partial disability statutorily required for her to be entitled to permanent total disability compensation.  See Minn. Stat. § 176.101, subd. 5(2)(a).  Judge Bonovetz drew no conclusions as to any medical, vocational, or other additional bases for entitlement to permanent total disability benefits.  See Schulte v. C. H. Peterson Constr., 278 Minn. 79, 83, 153 N.W.2d 130, 133-34, 24 W.C.D. 290, 295 (1967) (“[a] person is totally disabled if his physical condition, in combination with his age, training, and experience, and the type of work available in his community, causes him to be unable to secure anything more than sporadic employment resulting in an insubstantial income").^[3]  The employee contends that Judge Bonovetz’s conclusion is both factually and legally erroneous, in that (1) “depending upon the outcome of the RSD permanent partial disability rating [upon remand], the requisite permanent partial disability might exist, necessitating [further] findings on permanent total disability,” and (2) “even if, after an RSD permanent partial disability rating, [the employee] does not meet the permanent total thresholds, findings on permanent total still must be made in that the permanent partial disability thresholds, for permanent total, are unconstitutional.”

We remand the issue for findings pursuant to the employee’s first argument in the event that the judge finds the employee sufficiently permanently partially disabled to meet the statutory threshold for permanent total disability.  With regard to the employee’s second argument, this court is, as the employee has acknowledged in her brief, without authority to consider constitutional questions, and, in the event that the employee has not sustained the required permanent partial disability, we see no basis for requiring the judge to issue findings in anticipation of a potential appeal to the Minnesota Supreme Court on constitutional grounds.