The employee appeals from the compensation judge’s findings and order on remand, that the employee did not sustain a compensable rotator cuff tear and is not entitled to permanent partial disability benefits under Minnesota Rules 5223.0450, subparts 3 and 4.  We affirm.

On November 12, 2007, Darryl Michog [the employee] sustained a work-related injury to his left shoulder while lifting a case of chicken from a cart up to a chest-high shelf, in the course of his employment with Wal Mart Stores, Inc. [the employer].  At the moment of his injury, the employee heard a “pop” in his shoulder, followed immediately by the onset of pain in the shoulder and numbness and tingling in the left arm.  On the date of his injury, the employee was fifty-seven years old and was earning a weekly wage of about $444.00.^[1]

On December 24, 2007, the employee underwent an MRI scan of his left shoulder.  With the caveat that his evaluation was “severely limited due to motion artifact,” the examining radiologist indicated that he observed a “[s]uggestion of full thickness tear of the subscapularis tendon,” a “suspicion of a tear involving the interior glenoid labrum,” and a “[p]artial thickness tear of the supraspinatus tendon with suspicion of full thickness tear that is not demonstrated on the MR examination.”

On April 17, 2008, the employee was examined by orthopedic surgeon Dr. Bruce Piatt.  Physicians with whom the employee had treated previously had noted the suggestion of the possibility of a rotator cuff tear as the source of the employee’s complaints, but, after physical examination of the employee and review of his diagnostic imaging studies, Dr. Piatt concluded that, while the employee might have “maybe a minimal rotator cuff injury,” his primary problem was more probably related to “degenerative change” in the shoulder.  On June 27, 2008, Dr. Piatt performed a left shoulder arthroscopy with subacromial decompression and arthroscopic debridement of the glenohumeral joint, in treatment of what he diagnosed as left shoulder osteoarthritis, acromioclavicular joint arthritis, and subacromial impingement.  In his operative report, Dr. Piatt noted that the employee’s labrum was significantly degenerative but that his supraspinatus, infraspinatus, and subscapularis appeared to be “intact.”  He reported that the employee had had a type 3 acromion which had been converted to a type 1 with the acromionizer bur and that an anterior spur off the AC joint had been resected, although “a formial distal clavicle resection was not performed.”  On January 20, 2009, Dr. Piatt completed a Health Care Provider Report, in which he opined that the employee was entitled to permanent partial disability benefits for an impairment of 4% of his whole body, pursuant to Minnesota Rules 5223.0450, subparts 2.C. and 2.D. - - 3% for resection of the distal end of the clavicle under subpart 2.C. of the rule and 1% for chronic bicipital tendon rupture under subpart 2.D. of the rule.

On February 26, 2009, the employee was examined also, at the request of his attorney, by chiropractor Dr. Larry Stember.  In his report on that date, Dr. Stember opined that the employee had sustained a rotator cuff tear, which constituted an impairing condition entitling the employee to permanent partial disability benefits under subparts 3 and 4 of Rule 5223.0450, which he calculated to allow compensation for a 20% whole body impairment:  3% under subpart 2.C. of the rule for subacromial decompression, although, he concluded, no actual resection of the clavicle had been performed; 1% under subpart 2.D. for chronic bicipital tendon rupture; 2% under subpart 3.A.(1) for a partial thickness rotator cuff tear; and 14% under subparts 4.A.(1)(c), 4.B.(1)(c), and 4.C.(1)(b) of the rule, for loss of function.  On March 10, 2009, Dr. Piatt reiterated his 4% permanent partial disability rating without referencing his earlier observation of “maybe a minimal rotator cuff injury,” and the insurer paid compensation to the employee based on that 4% rating.

On June 23, 2009, the employee filed a claim petition, alleging entitlement to compensation for a 20% permanent partial disability, as recommended by Dr. Stember, less the 4% already paid by the insurer.  The employer and insurer eventually obtained a medical record review by orthopedist Dr. Richard Strand.  In his report on March 12, 2010, Dr. Strand agreed with the 4% rating of Dr. Piatt and its basis in the Minnesota Rules.  He explained, however, that the particular surgery performed by Dr. Piatt did not actually entail a distal clavicle resection but rather a removal of spurs at the AC joint.  Because the impingement syndrome corrected by the surgery was not actually provided for under the permanent partial disability schedules, he rated 3% of the employee’s total 4% disability under Minnesota Rules 5223.0450, subpart 2.A.C., as had Dr. Piatt but pursuant to the rating by analogy that is permitted under Weber v. City of Inver Grove Heights, 41 N.W.2d 918, 43 W.C.D. 471 (Minn. 1990).

The employee’s claim for the additional 16% permanent partial disability compensation came on for hearing before a compensation judge on April 7, 2010.  By findings and order issued April 23, 2010, the compensation judge determined that the weight of the evidence supported the reasoning and conclusion of Drs. Strand and Piatt, that the employee had sustained permanent partial disability to 4% of his body as a whole as a consequence of his November 2007 work injury.  The employee appealed, and, by a decision issued November 4, 2010, this court reversed in part, vacated in part, and remanded the decision of the compensation judge, for reconsideration in part as to whether the employee had sustained an impairing condition under Minnesota Rules 5223.0450, subpart 3 - - namely, a rotator cuff tear - - and, if so, whether that impairing condition is a substantial contributing factor in any loss of function rated under subpart 4 of that rule.

By agreement of the parties, the remanded issues were submitted to a compensation judge at the Office of Administrative Hearings by way of written argument without an in-person hearing, and the record in the matter closed on March 24, 2011.  Issues before the judge as stated in the judge’s findings and order included whether the employee had sustained an impairing condition under Minnesota Rules 5223.0450, subpart 3, and, if so, whether that impairing condition was a substantial contributing factor in any loss of function under Minnesota Rules 5223.0450, subpart 4.  By findings and order filed May 18, 2011, the compensation judge concluded in part that the employee “did not sustain a rotator cuff tear as a result of the November 12, 2007 incident,” such as would entitle him to permanent partial disability benefits under Minnesota Rules 5223.0450, subpart 3, and that he was therefore not entitled to any compensation for loss of function under subpart 4 of that rule.  On those findings, the compensation judge denied the employee’s claims for any permanent partial disability compensation beyond the 4% that had already been paid to him.  The employee appeals.

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.

The compensation judge found that the employee did not sustain a rotator cuff tear or any other condition identified under Minnesota Rules 5223.0450, subpart 3, such as would entitle the employee to additional compensation for loss of function under subpart 4 of that rule.  The employee contends that this finding is clearly erroneous and unsupported by substantial evidence.  He argues that there is ample evidence that the employee sustained at least a partial rotator cuff tear, that there is no evidence to the contrary, that Dr. Strand’s opinion regarding the employee’s permanent partial disability, on which the judge relied, was based on an incorrect interpretation of how the statute is to be applied, and that that opinion does not even address the issue of a possible rotator cuff tear.  We are not persuaded.

We acknowledge that there is evidence to support the employee’s claim that he sustained at least a partial rotator cuff tear as a result of his work injury.  But it is not the function of this court on appeal to assess whether substantial evidence might support a factual conclusion contrary to that reached by the compensation judge; this court’s function on factual review is only to assess whether substantial evidence exists to support the conclusion actually reached by the judge.  See Land v. Washington County Sheriff’s Dep’t, slip op. (W.C.C.A. Dec. 23, 2003); see also Ludford v. Honeywell, Inc., slip op. (W.C.C.A. Mar. 17, 2004); Moe v. Dr. Matthew A. Gahn, slip op. (W.C.C.A. Dec. 31, 2003); Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734, 40 W.C.D. 948, 957 (Minn. 1988) (“whether [the appellate court] might have viewed the evidence differently is not the point, but whether the findings of the compensation judge are supported by evidence that a reasonable mind might accept as adequate”).  Here, we conclude, there exists such evidence.

Although there appeared to be a “suggestion” and a “suspicion” of possible tears in the employee’s rotator cuff on his December 24, 2007, MRI scan, the radiologist noted that his evaluation was “severely limited due to motion artifact” and that at least one of the suspected tears was expressly “not demonstrated on the MR examination.”  Moreover, when the employee’s own surgeon, Dr. Piatt, actually looked inside the employee’s shoulder arthroscopically in the performance of his surgery on June 27, 2008, to correct the employee’s degenerative condition, he found the questionable parts of the employee’s shoulder - - the supraspinatus, the infraspinatus, and the subscapularis - - all “intact.”  Indeed, both Dr. Piatt’s rating and Dr. Strand’s rating of the employee’s disability constitute in themselves expert opinion - - and, as such, evidence - - in support of the judge’s decision.  The employee suggests that Dr. Piatt himself diagnosed a torn rotator cuff on February 5, 2009, in a letter to the insurer’s claims manager, and that Dr. Strand based his opinion on an incorrect legal interpretation of the permanency schedules, but we agree with the compensation judge, that the employee has not borne his burden of proof.

It is true that, in his February 5, 2009, letter to the claims manager, Dr. Piatt appears to admit that he “inappropriately” diagnosed a distal clavicle resection where he should have indicated “that the [employee] had a partial-thickness rotator cuff tear, which would give him a 2% PPD rating [under rule] 5223.0450, subpart 3A1.”  However, his immediately subsequent Health Care Provider Report, on March 10, 2009, contains no mention of any rotator cuff tear, instead including in its diagnosis only a tear of the biceps tendon and again rating the employee’s total permanent partial disability at 4% - - 3% again for a clavicle resection under subpart 2.C. of the rule and 1% for the bicipital tendon rupture under subpart 2.D. of the rule.  In a subsequent letter to the insurer’s claims manager on March 30, 2009, Dr. Piatt explains that he “did perform a limited distal clavicle resection,” in that he “did not formally removed the entire distal clavicle, but removed a large osteophyte from the interior surface of the clavicle.”  Dr. Piatt’s diagnosis of a rotator cuff tear is equivocal at best.

With respect to Dr. Strand’s application of the schedules, the employee contends that Dr. Strand was legally incorrect in finding Dr. Stember incorrect in combining his ratings of conditions described under subpart 2 of rule 5223.0450 with his ratings of conditions described under subpart 3 of the rule.  Whatever might be the employee’s arguments in this regard, the issue is moot for our purposes here on appeal.  The judge based his decision not on Dr. Strand’s opinion that a rotator cuff tear, listed under subpart 3 of the rule, cannot be combined with any condition described under subpart 2, but on the fact that the employee did not sustain a rotator cuff tear in the first place, such as would entitle him to combine such a rating with a rating for loss of function under subpart 4.  Nor was it essential to Dr. Strand’s rating that he address and exclude all or even any possible diagnoses contrary to his own, such as rotator cuff tear, prior to issuing a rating based on his own diagnoses.  Dr. Strand, agreeing with an established diagnosis of record, rated the employee’s chronic bicipital tendon rupture as a 1% whole body impairment under Minnesota Rules 5223.0450, subpart 2.D.  Noting also that surgically relieved impingement syndrome was not listed elsewhere under the permanency schedules, he reasonably, under the Weber rule,^[2] rated his diagnosis of a surgically removed bone spur as a 3% whole body impairment under subpart 2.C. of that rule, implying what Dr. Piatt later described as a “limited” distal clavicle resection.

Because the radiological findings were not definitive, because the judge’s decision was supported by expert medical opinions and because the judge’s factual conclusions were not otherwise unreasonable, we affirm in its entirety the compensation judge’s decision here on remand.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239; see also Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.A. 364, 373-73 (Minn. 1985) (“the 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.”)