Validity and reliability of the “Pendleton test”: An innovative special test for intraarticular hip pathology

Abstract Background Hip pain is common in sports medicine. Utility of legacy special tests for examination of intraarticular hip lesions is mixed at best. Objective To establish criterion‐reference validity, intertester reliability, and test–retest reliability of the Pendleton test in screening for intraarticular hip pathology. Design Criterion standard, blinded. Setting Tertiary care, institutional. Patients Thirty patients (16 female, 14 male) with chronic anterior or anterior‐medial hip pain were recruited from a military outpatient sports medicine clinic. Interventions The independent variables for test–retest and intertester reliability were session and tester, respectively. The relationship between intraarticular hip pathology and pain level was examined as a secondary objective. Main Outcome Measures Magnetic resonance imaging (MRI) positivity for intraarticular pathoanatomic injury was used as the criterion reference for validity. Sensitivity, specificity, positive predictive value, negative predictive value, and receiver‐operator curves were calculated. Cohen's kappa statistics were used for establishing test–retest and intertester reliability. Results MRI positivity was 33% and 50% for anteroinferior or any intraarticular lesions, respectively, and was not significantly associated ( β  = 0.59, p  = .20) with pain level when adjusted for gender, age, and rank. Sensitivity of the Pendleton test was 70% for anterior intraarticular lesions and 67% for any intraarticular lesion. Specificity was 15% for anterior intraarticular lesions and 6.7% for any intraarticular lesion. Positive predictive value was 29% for anterior intraarticular lesions and 42% for any intraarticular lesions, and negative predictive value was 50% and 17%, respectively. The area under the curve of the Pendleton test was 0.60 (95% confidence interval: 0.37–0.84) for anterior articular lesions and 0.71 (95% confidence interval: 0.52–0.90) for any intraarticular lesions. Intertester reliability (kappa = 0.77, p  < .001) and test–retest reliability (kappa = 0.80, p  < .001) were substantial. Conclusions The Pendleton test exhibited excellent reliability, adequate sensitivity, and poor specificity for detecting intraarticular lesions of the hip. The presence of intraarticular lesions on MRI was not associated with hip pain level.