Hip resurfacing: expectations and limitations

Open Access-This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the source is credited. Sir—We read with interest the article by Pieter T. J. Spierings (2008) pertaining to the hip resurfacing expectations and limitations. We would like to make some comments and discuss some of the conclusions of the article: 1. For the conservative approach of the acetabular bone stock, from our experience we do not agree that more bone is removed in hip resurfacing (HRA) than in total hip arthroplasty (THA). The author does not take into account the difference in gender in the indications of both procedures. That a small survey about sales of prostheses done among the largest distributors in the Netherlands showed that there would be more excessive bone loss in resurfacing is possible, but it has been well established in all papers about HRA and THA, that the majority of patients are male in HRA (70%), female in total hip (70%) (Buergi and Walter 2007). In general the cup size in females is about 6 to 8 mm smaller than the size in male patients, which supports our point that there is not a difference between the 2 procedures even in the Netherlands. There is also a difference in bone removal of the acetabu-lum in different implants because of different instrumentation, techniques and design, but this has not yet been shown to be statistically significant. Vendittoli in a prospective, randomized study compared conservation of acetabular bone after THA and HRA of the hip (Venditolli et al. 2006). The results suggested that removal of bone on the acetabular side in HRA was comparable with that of THA, the mean or median diameters of the last reamer used or the mean size of the acetabular component (54.90 mm (44 to 64) for resurfacing arthroplasty and 54.74 mm (48 to 62) for THR, p = 0.770. The same results were also seen in other studies (Naal et al. 2009). Moonot showed hip resurfac-ing acetabular components was 2.03 mm less than that of the acetabular components in the uncemented total hip replacements (p < 0.0001) (Moonot et al. 2008). We will not deny that an excessively large cup is never done in resurfacing, but this is seen as a mistake in the resurfacing technique as is also the high abduction angle in …