RT Journal A1 Field, Richard E. A1 Rajakulendran, Karthig T1 The Labro-Acetabular Complex JF The Journal of Bone & Joint Surgery JO The Journal of Bone & Joint Surgery YR 2011 FD May 4 VO 93 IS Supplement_2 SP 22 OP 27 DO 10.2106/JBJS.J.01710 UL http://dx.doi.org/10.2106/JBJS.J.01710 AB The human hip is subjected to several hundred million loading cycles during a lifetime. Hip instability and femoro-acetabular impingement cause damage to the rim of the acetabulum. The acetabular rim is a highly specialized structure known as the labro-acetabular complex. A unidirectional flow of synovial fluid has been identified in this region. The synovial fluid circulation is driven by the bellows-like movement of the zona orbicularis and depends on hip flexion and extension. Surgical repair of the damaged labro-acetabular complex should satisfy two goals. First, the labrum should be preserved or reconstructed when possible. Second, the precipitating cause of the labro-acetabular damage must be addressed.