The dimensions of the hip labrum can be reliably measured using magnetic resonance and computed tomography which can be used to develop a standardized definition of the hypoplastic labrum

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA sports traumatology, arthroscopy : official journal of the ESSKA, 2021-05, Vol.29 (5), p.1432-1452
• Main Authors: Walker, Madison, Maini, Larissa, Kay, Jeffrey, Sansone, Mikael, Mascarenhas, Vasco V., Simunovic, Nicole, Ayeni, Olufemi R.
• Format: Article
• Language: English
• Subjects: Acetabulum; Arthroscopy; Bone dysplasia; Clinical decision making; Clinical Medicine; Computed tomography; Decision making; Hip; Imaging techniques; Klinisk medicin; Labrum; Magnetic resonance imaging; Medical imaging; Medicine; Medicine & Public Health; Orthopedics; Patients; Resonance; Sports Medicine; Tomography
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-020-06330-9

Purpose The purpose of this study was to examine the existing literature to determine the dimensions of the acetabular labrum, with a focus on hypotrophic labra, including the modalities and accuracy of measurement, factors associated with smaller labra, and any impacts on surgical management. Methods Four databases (PubMed, Ovid [MEDLINE], Cochrane Database, and EMBASE) were searched from database inception to January 2020. Two reviewers screened the literature independently and in duplicate. Methodological quality of included papers was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. Where possible, data on labral size were combined using a random effects model. Results Twenty-one studies (5 level II, 9 level III, 7 level IV) were identified. This resulted in 6,159 patients (6,436 hips) with a mean age of 34.3 years (range 8.4–85). The patients were 67.3% female with an average follow-up of 57.3 months. There was no consistent definition of labral size quoted throughout the literature. The mean width on MRI/MRA was 7.3 mm (95% CI 6.9–7.8 mm), on computed tomography arthrography was 8.7 mm (95% CI 8.0–9.3), and during arthroscopy was 5.0 mm (95% CI 4.9–5.2). Inter-observer reliability was good to excellent in all modalities. Labral hypotrophy may be associated with increased acetabular coverage. Hypertrophic labra were highly associated with acetabular dysplasia ( r  = − 0.706, − 0.596, − 0.504, respectively; P