Anatomical study of the "trochanteric bursa".

Abstract

To resolve ambiguity in the literature about the anatomy of the "trochanteric bursa" or trochanteric subgluteus maximus bursa, this study examines the constancy, structure, and relationships of this bursa in a series of anatomical dissections of the hip. Sixteen embalmed hip specimens, from subjects aged 63-91 years, were examined. Subgluteus maximus bursae were demonstrated in 13 hips. In each of these a bursa, the deep bursa, was seen immediately superficial to the common attachment of the gluteus medius, minimus, and vastus lateralis muscles onto the greater trochanter. In five hips a smaller second bursa, the superficial bursa, was reflected with the gluteus maximus muscle. In two hips, four bursae were identified. The additional bursae were associated with either the deep or the superficial bursa. Examination of histological samples from the bursal walls confirmed the presence of a synovial lining in varying stages of development in seven of the eight bursae examined. Branches of the inferior gluteal nerve were seen to supply deep and superficial bursae in two dissections. The study data indicate that subgluteus maximus bursae at the level of the greater trochanter are an expected finding in the older age group and that they vary in number, position, and histological appearance. These features give rise to the hypothesis that these bursae are acquired as a consequence of excessive friction between the greater trochanter and the gluteus maximus as it inserts into the fascia lata.