Then and now, design matters: significant improvements in the clinical and radiological performance of cementless hip resurfacing
Metal-on-metal (MoM) bearings with a cemented femoral component and a cementless acetabular shell has historically been the gold standard for fixation in surface arthroplasty (SA) of the hip. Lately, there has been an increase in the availability of cementless femoral fixation. Since there is a paucity of literature on the clinical performance of modern generation cementless designs in SA, we aimed to perform a review of the literature on this type of fixation, as well as to report our institutional mid-term survival with a MoM cementless hip design. A comprehensive literature search provided information on joint arthroplasty registries, case-series, case-controlled studies and randomized controlled-trials reporting on the performance of hip resurfacings with cementless femoral fixation and its comparison with cemented fixation. Even though initial attempts of cementless femoral fixation showed high failure rates in the early 1990s, modern cementless porous-coated designs have proven to be non-inferior, with excellent mid- and long-term results in terms of survival and clinical outcomes. Our experience showed a two-, five-, and eight-year survivorships of 99.6% (95% CI: 98.8–100%), 98.3% (95% CI: 96.3–100%), and 98.3% (95% CI: 96.3–100%), respectively; with only 2 aseptic femoral failures. In SA of the hip, cementless femoral fixation has evolved in such a fashion that is the fixation of choice for SA in many centers. Modern implants have similar outcomes to that of cemented fixation in the early to mid-term. However, long-term clinical outcomes are still necessary to determine whether these results will continue or surpass that of cemented femoral fixation in SA.