Ph Hernigou (Créteil)
Resurfacing has been reported to be efficacious with respect to improvement in physical function and reduction in pain in several papers. However, resurfacing may not have as predictable an outcome nor as long-lasting a result as total hip arthroplasty. Patients may have the majority of their symptoms relieved, yet still suffer from groin pain from the contact of the metal prosthesis onto the native acetabular bone. This is similar in nature to the results seen in the bipolar population.
With respect to reliability of the surgical outcome, resurfacing offers a potential advantage over core decompressions, fibular grafts, and indeed osteotomies, given the difficulty in preoperatively delineating cartilaginous flap tears associated with osteonecrosis. resurfacing addresses not only the osteonecrosis, but also the cartilaginous issues by complete removal of the cartilaginous surface intraoperatively.
Resurfacing is perhaps the most technically difficult of all the procedures recommended for osteonecrosis of the hip, given that a surgical dislocation of the hip is required. Furthermore, given the limited access to the femoral head, there are technical challenges with proper component positioning. As well, great care must be taken to avoid notching of the femoral neck, which is intimately related to jig placement prior and subsequently a function of surgical exposure.
In order to improve the reliability of the outcome of the operative intervention and to decrease the incidence of groin pain, several prosthetic manufacturers have reintroduced the concept of a resurfacing with a concomitant cup arthroplasty, resulting in a metal-on-metal bearing surface. Unfortunately, the orthopaedic audience is well aware of previous experience with this concept, subsequently deterring many surgeons from embracing the revisiting of this concept.
A major limitation with respect to acetabular resurfacing with concomitant resurfacing relates to the amount of host bone that needs to be removed in order to accommodate the acetabular component. The limiting aspect of the surgical intervention is the native size of the femoral neck, which dictates the size of the femoral component utilized in order to avoid notching of the femoral neck and subsequent periprosthetic fracture. However, in doing so, the surgeon is often forced to ream the acetabulum to an extent greater than would be required for a primary total hip arthroplasty. This represents a philosophical problem with respect to the entire concept of resurfacing combined with cup arthroplasty given the fact that the postulated « conservative » procedure on the femoral side is coupled with an « aggressive » surgical approach to the acetabulum.