Limitations of arthroscopy for managing coxa profunda.

Coxa profunda is a complex entity that can result in femoro-acetabular impingement (FAI). A meticulous evaluation of the type of acetabular overcoverage is essential to determine which treatment is best suited to each individual patient. Focal overcoverage with no posterior impingement can be treated by arthroscopic recontouring of the disproportionate acetabular wall. Any femoral deformities should be managed during the same procedure. General overcoverage, with predominant postero-inferior impingement, requires open surgery to obtain access to the entire acetabular rim. Rim resection should be sparing, to avoid removing an excessive proportion of the joint surface, yet sufficient to eliminate the impingement. In the event of protrusio acetabuli, which is the extreme form of coxa profunda, reverse peri-acetabular osteotomy should be considered, particularly if the acetabular roof angle is reversed. In some patients, chiefly those with coxa vara, valgus femoral osteotomy should be considered as a means of redirecting the loads towards the acetabular roof, thereby diminishing the forces that tend to drive the femoral head deeper into the socket.