THE BIFID POSTERIOR LABRUM: AN ANATOMICAL VARIANT OF THE ACETABULAR LABRUM

A. Tzaveas, R. Miller, R. Villar
The Richard Villar Practice, Wellington Hospital, London, UK
Aim of the study: To present three cases of a bifid posterior labrum in the hip joint diagnosed arthroscopically.
Material and methods: Three patients underwent hip arthroscopy because of chronic pain in the joint. The first, aged 17, had MRI appearances of a tear of the posterosuperior portion of the labrum. Two further patients, aged 35 and 36, who had symptoms from the hip also underwent arthroscopy.
Results: All patients showed the arthroscopic appearance of a bifid acetabular labrum along its posterior portion. As the labrum was found to be stable on the acetabular rim, we did not proceed to any therapeutic intervention. In addition, the patients had other intra-articular lesions, such as a tear of the anterior labrum, early osteoarthritic changes and the presence of loose bodies, which were treated accordingly.
Conclusions: Although the anatomy and histology of the acetabular labrum have been described extensively, there are no published studies confirming the existence of anatomical variants in its shape. We therefore propose that the bifid posterior labrum is an anatomical variant rather than a pathological lesion. Although tears of the posterior labrum are not unknown, they are rare. Consequently, any preoperative MRI appearance of a tear of the posterior labrum should be approached with caution, so that a false positive result is avoided.