Diagnostics of Intra-articular Hip Pathology: Relation Between Physical Tests, Imaging, and Arthroscopy Findings

Abstract

The clinical diagnosis of intra-articular hip pathology, like femoroacetabular impingement (FAI) and labral pathology, is mostly based on imaging techniques as X-ray and Magnetic Resonance Imaging Arthrography (MRI-A). Although there is a vast amount of physical diagnostic tests available, studies have shown that the large diversity of tests, the lack of standardization and the low quality of research make it difficult to provide the clinician with a correct diagnosis based on these physical diagnostic tests. The purpose of this study was to examine the agreement between physical diagnostic tests and imaging findings using the arthroscopy results as gold standard in a population of patients with intra-articular hip pathology. A retrospective cohort study was performed. In the patient files outcomes on physical examination tests, imaging and operative findings of 78 patients (43 males/35 females) who had undergone an arthroscopy for intra- articular hip pathology were reviewed by a single independent researcher. Subjects had a mean age of 36.4 (range, 16-59 years). The anterior hip impingement test, flexion-abduction-exorotation test (FABER), resisted straight leg raise test (RSLR), Fitzgerald test, Thomas Test, and Scour test were investigated. A detailed imaging evaluation including alpha angle, center edge angle, cross-over sign, protrusio acetabuli, joint space narrowing, Tönnis grade and signs of labral pathology was performed. All patient records were retrieved to verify the exact diagnosis based on arthroscopy. The agreement of a positive finding on the physical test versus arthroscopy was 91% (71/78) for the anterior impingement test, 82% (64/78) for the FABER test, 21% (15/69) for the RSLR test, 74% (56/76) for the Fitzgerald test, 14% (10/74) for the Thomas test, and 49% (20/41) for the Scour test. Currently 50% of the database is complete. Full analysis of agreement between physical tests, imaging and arthroscopy findings will be finished at the end of June. Analysis will also be performed for clusters of physical tests and for specific intra-articular disorders. To the authors' knowledge, it is the first study to investigate these physical diagnostic tests independently and combined versus imaging and arthroscopy results in this population. This may lead to a faster and more accurate diagnosis of intra-articular hip pathology.