Limitations of arthroscopy for managing coxa profunda

Abstract

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.

Limitations of Postless Hip Arthroscopy for a Patient with Coxa Profunda

“…Across the literature, indications and limitations of postless technique are seldom discussed. The utility of postless distraction for patients who require greater traction force, such as patients with coxa profunda or other challenging bone anatomy, is unknown 2 , 3 , 7 , 13 . For this reason, Mei-Dan et al's observation that less than 1% of hips are undistractable using postless technique is difficult to generalize to patients with deep hips 2 .…”

“…In evaluating postless systems, Kollmorgen et al indicated weight as a disadvantage for patients under 120 lbs 4 , suggesting that weight may limit the traction force attainable. Because patients with coxa profunda are likely to require more traction force during hip arthroscopy 7 , additional studies are necessary to quantify the force required and provide guidance for the use of postless distraction on patients with deep hips.…”

“…In addition, there are some variations in coxa profunda morphology. Because the Tönnis angle is often zero or negative in coxa profunda cases, the acetabular rim can obstruct instrument introduction into the joint 7 . A hip with coxa profunda and a mild sloping sourcil (Fig.…”

“…Furthermore, the significant traction force necessary to arthroscopically treat patients with coxa profunda also predisposes them to a higher risk of traction-related injuries 1 , 7 . Telleria et al reported that each 1 lb increase in traction force increased the likelihood of a nerve event by 4% 1 .…”

“…However, indications and limitations for postless distraction are seldom discussed. Patients with coxa profunda, in which the acetabular fossa is medial to the ilioischial line on a standard anteroposterior radiograph, routinely require more traction force than patients without this finding and consequently are more prone to traction-related complications 1 , 7 . However, the degree to which postless distraction can provide visualization into deeper hips is unknown.…”