Examination of acetabular labral tear: a continued diagnostic challenge Michael P Reiman, 1 Richard C MatherIII, 2 Thomas W Hash II, 2 Chad E Cook 3 ▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/ bjsports-2012-091994). 1 Community and Family Practice, Duke University School of Medicine, Durham, North Carolina, USA 2 Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina, USA 3 Department of Physical Therapy, Walsh University, North Canton, Ohio, USA Correspondence to Dr Michael P Reiman, Community and Family Practice, Duke University School of Medicine, 2200 W. Main, Durham, NC 27705, USA; michael.reiman@duke.edu Accepted 25 June 2013 To cite: Reiman MP, Mather RC, Hash TW, et al. Br J Sports Med Published Online First: [ please include Day Month Year] doi:10.1136/bjsports-2012- 091994 ABSTRACT Acetabular labrum tears (ALT) are present in 22–55% of individuals with hip or groin pain. Tears can occur as a result of trauma or degeneration and are markedly associated with femoral acetabular morphological variations. An ALT can lead to biomechanical deficiencies and a loss of stability to the coxafemoral joint due to the labrum serving as a stabilising structure of this joint. The diagnosis of ALT is complex and multidimensional. Although tremendous improvements in diagnostic utility for ALT have occurred in the past 25 years, there are few patient history, clinical examination and special test findings that are unique to the condition. Imaging methods such as MRI, CT and ultrasonography have demonstrated reasonable accuracy, but not at a level that allows use as a stand-alone measure. Outcomes measures that focus on functional limitation or that are used to measure recovery should envelop the complexities of the condition and be captured using both self-report and physical performance measures. Only when patient history, objective testing, clinical examination special testing and imaging are combined can a clinician fully elucidate the multidimensional diagnosis of ALT. INTRODUCTION The reported prevalence of acetabular labral tears (ALT) in patients with hip or groin pain ranges from 22% to 55%. 1–4 Differential diagnosis of the hip joint poses a diagnostic dilemma, particularly given that pain in the hip region is often difficult to localise to a specific pathological structure. With the evolution of improved diagnostic imaging and advanced surgical techniques, examination of the hip joint and periarticular structures as a primary pain source for hip-related pain/dysfunction has received a significant increase in attention. 5–7 Although limited information exists in support of diagnostic utility, emphasis on patient history, clinical examination findings, MRI, MRI arthrogra- phy (MRA) CT arthrography and anaesthetic intra-articular injection pain response is currently advocated for determining the presence of intra-articular hip joint pathology. 8 Clearly delin- eating the specific pathology in the hip can be diffi- cult, 9 10 since patients visit multiple healthcare providers over an extended period of time prior to diagnosis of ALT. 11 Additionally confounding the diagnostic process of the hip joint is a lack of con- sensus regarding what elements of the examination are considered essential. 12 The purpose of this paper was to examine the most current evidence and provide a systematic approach (based on this evidence) for examination of patients with a sug- gestion ofALT. ANATOMY/BIOMECHANICS/EPIDEMIOLOGY/ MECHANISM OF INJURY The acetabular labrum is a fibrocartilaginous struc- ture that lines the majority of the acetabular socket. 13 Histologically, the labrum can be divided into capsular and articular portions. 14 15 The capsu- lar portion consists of dense connective tissue (colla- gen types I and III), whereas the articular portion consists of fibrocartilage (collagen type II) 14 and is contiguous with the acetabular articular cartilage. 16 Blood supply to the labrum enters from the capsule and supplies the outer 1/3 of the labrum. 14 Pain-sensing free nerve endings are located most densely in the superior and anterior portions of the labrum, suggesting that it is a pain-generating structure. 14 16 The acetabular labrum increases the articular surface area by 22% and acetabular volume by 33% and is believed to create a seal in the hip joint. 16 Biomechanical analyses suggest that the labrum is stressed by a compressive load and extremes of hip joint motion. 14 17 18 Therefore, a tear of the labrum alters physiological functions such as enhancement of joint stability and equitable load distribution. 14 Acetabular labral tears are common and fre- quently asymptomatic; 96% of cadaver hips with a mean age of 78 years (range, 61–98years) had ALT, with 74% of the tears located in the anterosuperior quadrant. 16 Arthroscopic observations support the concept that femoroacetabular impingement (FAI), labral disruption, chondral lesions or combinations of each are frequently inter-related and part of a continuum of degenerative joint disease. 18–21 Most ALTs are characterised by the insidious onset of symptoms. An increased prevalence of ALT has been shown to occur in athletes participat- ing in tennis, ballet, hockey, football and soccer. The repetitive twisting and pivoting motions typic- ally performed by these athletes in a flexed, weight- bearing position most likely create microtrauma, resulting in the eventual mechanical alteration of the joint. 22 Five categories of ALT have been described based on aetiology: traumatic, congenital, degenerative, capsular laxity and idiopathic. Traumatic tears have an identifiable history and can involve additional acetabular trauma. 13 Congenital tears are charac- terised by the presence of acetabular dysplasia. 22 Degenerative labral tears are identified through radiographic evidence and often involve other degenerative changes of the joint. 22 Capsular laxity can be divided into either global laxity (due to sys- temic connective tissue disorders) or focal rota- tional laxity known to occur in sports such as golf, hockey and baseball. 23 In the absence of other Reiman MP, et al. Br J Sports Med 2013;0:1–11. doi:10.1136/bjsports-2012-091994 1 Review BJSM Online First, published on July 31, 2013 as 10.1136/bjsports-2012-091994 Copyright Article author (or their employer) 2013. Produced by BMJ Publishing Group Ltd under licence.