Background: Hypertrophic labrum in dysplastic hip has been frequently reported and is known as limbus in developmental dysplasia of the hip. However, hypertrophic labrum without hip dysplasia has not been reported to date. The purpose of this study was to define hypertrophic labrum and to investigate the prevalence and clinical significance of an abnormally hypertrophic labrum in non-dysplastic hips.
Methods: Between 2007 and 2014, direct CT arthrography was performed in 464 patients (470 hips) who had chronic groin pain and positive impingement or Faber test. There were 189 male (192 hips) and 275 female (278 hips) patients. The mean age was 46.8 years (range, 16-74 years). The hypertrophic labrum was defined as a labrum wider than two standard deviations away from the mean. Surgical correlation of hypertrophic labrum was obtained in cases with hip arthroscopy by a single surgeon.
Results: Seventeen hips (3.6%) were found to have a hypertrophic labrum which had a mean width of 11.2 mm (±1.1) (range, 9.8-14.1 mm). The average width (±SD) of the labrum without hypertrophy was 5.5 mm (±2.4) (range, 2-9.8 mm). Arthroscopic findings of the hypertrophic labrum included fissure and longitudinal tear at the chondrolabral junction and they were associated with chondral abnormality adjacent to the lesion.
Conclusions: Hypertrophic labrum without hip dysplasia is not rare with a high incidence of tears. Care should be taken during arthroscopic access to the hip joint in patients with this morphologic variation as iatrogenic damage can occur more easily.
Level of evidence: Case Series; Level IV.
Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.