The validity and accuracy of clinical diagnostic tests used to detect labral pathology of the hip: A systematic review

Abstract

Acetabular labral tears are an area of increasing interest to clinicians involved in the diagnosis of musculoskeletal complaints of the hip. This review systematically evaluated the evidence for the diagnostic accuracy and validity of reported symptoms, physical examination and imaging in this complex population. Studies published in English prior to May 2010 were included. One reviewer searched information sources to identify relevant articles. Two reviewers independently assessed studies for inclusion, extracted data and evaluated quality using the Quality Assessment of Diagnostic Studies Tool.

Twenty one studies were included. Meta-analysis was limited owing to heterogeneity between studies. Results showed Magnetic Resonance Arthrography to consistently outperform Magnetic Resonance Imaging. Computerised Tomography also showed high accuracy levels for the few studies identified. Studies investigating physical tests were of poor quality demonstrating a need for further research in this area. Symptoms likely to be present in patients presenting with acetabular labral tears were found to be anterior groin pain and mechanical hip symptoms; however, additional good quality studies are needed to consolidate findings.

Introduction

Intra-articular lesions of the hip have increasingly been identified as the source of unexplained hip and groin pain (Kelly et al., 2005). In a recent study evaluating diagnosis of longstanding groin pain, the most prevalent condition was hip joint pathology, with acute labral tears and impingement syndromes accounting for a large proportion of diagnoses (Bradshaw et al., 2008). Prevalence of acetabular labral tears in patients presenting with hip or groin pain has been reported to be between 22% (Narvani et al., 2003) and 55% (McCarthy et al., 2001). As a diagnosis, this is further supported by reports of positive outcome from arthroscopic resection and excision of the torn acetabular labra (Fitzgerald, 1995, McCarthy and Busconi, 1995, Farjo et al., 1999, Byrd and Jones, 2001).

The diagnosis of hip injuries is complex due to the challenging anatomy and biomechanics around the hip and groin (Feeley et al., 2008). Many factors predispose patients to acetabular labral tears, including femoral acetabular impingement, Legg-Calve-Perthes Disease (LCP), slipped capital epiphysis, and repetitive or acute hip trauma (McCarthy et al., 2003, Martin et al., 2006). Clinicians, particularly musculoskeletal physiotherapists working in extended roles, require a thorough knowledge of presenting symptoms, physical findings and imaging techniques, and their diagnostic accuracy in relation to acetabular labral tears, to recognise the need for early investigations and to guide appropriate management. To be useful to clinicians, a diagnostic test must possess high sensitivity to rule in a condition and high specificity to rule out a condition (Deeks, 2001). Alongside other summary statistics, sensitivity and specificity provide measures of diagnostic accuracy (Deeks, 2001).

History taking was found to be the most important part of the diagnostic process by Peterson et al. (1992) in a study on medical outpatients, with examination and laboratory testing improving diagnostic ability by a further 12% and 11% respectively. McCarthy and Busconi (1995) judged history taking and physical examination to be the best predictors of intra-articular hip pathology, in their cohort study of patients with refractory hip pain (n = 59). The patient history and physical findings are therefore important entities to explore in this patient population alongside diagnostic imaging.

Symptoms associated with acetabular labral tears include pain, locking, catching, instability, giving way, and stiffness (Martin et al., 2006). These symptoms, however, are also highly prevalent in other patient populations including those with LCP, loose bodies, degenerative joint disease and osteonecrosis (O’Leary et al., 2001). A number of physical tests are used to assess the hip complex. Those routinely used to test for acetabular labral tears include the Modified Thomas Test (Narvani et al., 2003), hip impingement test (Narvani et al., 2003, Burnett et al., 2006), hip quadrant test (Narvani et al., 2003), Scour test (Martin et al., 2008) and Fitzgerald’s provocative test (Fitzgerald, 1995). Most of the physical tests that are used to aid diagnosis of labral pathology have not been formally validated (Martin et al., 2006).

Current imaging techniques include magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) (Czerny et al., 1996) and computerised tomography (CT) (Yamamoto et al., 2007). Hip arthroscopic examination is time consuming, costly and invasive (Keeney et al., 2004) and can only be performed by a small number of specialist orthopaedic surgeons. Consequently, most clinicians are reliant on conventional methods of diagnosis using data from the patient history, physical examination and accessible forms of imaging to guide decision making in clinical practice.

The objective of the study was to determine diagnostic accuracy and validity of the patient history, physical examination and imaging for the diagnosis of acetabular labral tears in patients presenting with hip pain. Current literature on the diagnosis of labral pathology was identified and presented to support clinical decision making when considering labral pathology as a differential diagnosis.