With the recent approval by the FDA of the Birmingham Hip Resurfacing Implant, there has been interest generated primarily by the implant manufacturer for surface replacement. This is a procedure that has been part of the orthopedic armamentarium for over 30 years. Historically, the surface replacement procedure has never been as popular or successful as total hip replacement. With the change in materials going to a metal-on-metal type of articulation, the procedure has improved and there is hope that this will be a more viable option in the future.
The benefit of surface replacement is the ability to use a very large femoral head which allows better motion with lower risk of dislocation and by not violating the proximal femur to the same extent as a hip replacement, it has been touted as affording an easier revision.
In reality, in the past, there has been more bone sacrifice on the socket side during a surface replacement thus compromising the ability of the surgeon to revise these procedures. Bone loss in the proximal or top part of the femur in revision surgery is not a difficult problem to deal with. However, bone loss on the socket side due to increased reaming for a surface replacement has traditionally made for more challenging revisions.
With the advent of large head total hip replacement over the last few years and the use of one-piece acetabular metal-on-metal components, hip replacement has now progressed to a point where similar sized heads are available for hip replacement without having to perform a different type of procedure such as surface replacement. As a result of this, there has been a significant increase in the use of large head total hip replacements over the last 12 months. Many of the advantages previously attributed to surface replacement are now available with traditional hip replacement using the large head format. I predict that as a result of this, the interest in surface replacement will be somewhat dampened in the United States as most surgeons prefer to do a hip replacement procedure which is familiar and more straight forward then a surface replacement. The theoretical advantages of surface replacement have largely been accomplished by large head total hip replacements. Time will tell and I think we will see a shaking out of these differences over the next 12 to 24 months.