Screw Fixation of Os Acetabuli: An Arthroscopic Technique.

An os acetabuli (OA) increases the contact area and surface area of the acetabulum and is important to maintain congruity of the hip joint. Thus preservation of this ossicle is important to prevent loss of contact area and ensure containment of the femoral head. We describe an all-arthroscopic approach to the fixation of OA with a compression screw. Initially, the fibrous tissue is debrided between the acetabular rim and the OA, a guidewire is placed through the OA up to the acetabular rim, and a screw is inserted over the wire. Compression of the OA is achieved with bone-to-bone contact. This technique prevents loss of femoral head coverage, reducing the risk of subluxation and subsequent osteoarthritis.