title: Internal rotation resistance strength test: a new diagnostic test to differentiate intra-articular pathology from outlet (Neer) impingement syndrome in the shoulder.
abstract: This prospective study introduces a new sign to differentiate between outlet impingement and non-outlet (intra-articular) causes of shoulder pain in patients with positive impingement sign: the internal rotation resistance strength test (IRRST). It was hypothesized that positive test results are predictive of non-outlet impingement, whereas negative test results confirm outlet impingement. A prospective comparison between IRRST and arthroscopic findings of 115 consecutive patients showed the test to be highly accurate in differentiating between these two diagnoses (positive predictive value 88%, negative predictive value 96%, sensitivity 88%, specificity 96%, and accuracy 94.5%). The IRRST, in conjunction with impingement and apprehension signs, adds to our armamentarium of tests that distinguish between subacromial outlet impingement and intra-articular forms of pathology.
authors.affiliation: Advanced Orthopedic Centers, Richmond, Va 23294, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Zaslav
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001182:Arthroscopy / Q000379:methods*; D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000209:etiology; D010808:Physical Examination / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012783:Shoulder Dislocation / Q000175:diagnosis* / Q000601:surgery; D019534:Shoulder Impingement Syndrome / Q000175:diagnosis* / Q000601:surgery