Patient-Specific Techniques for Hip Replacement

Background * In the 19th century, Sir John Charnley successfully introduced total joint replacements for hips. In order to prevent implant fixation failure and accelerated polyethylene wear, it was initially recommended that implants were systematically positioned in a "biomechanically-friendly" way, which disregarded most of the individual anatomy (medialized acetabular cup, systematized cup version and inclination, etc.) * While those initial surgical techniques made popular and clinically successful total joint replacements, many complications (aseptic loosening, pain, excessive wear) have remained and mainly the persistence of frequent instability after THA. In response to those complications, many improvements were developed in the area of joint replacement over the last few decades, with one the most recent dating from 2017 and being the development of a surgical technique Rationale * The kinematic alignment (KA) technique for total hip arthroplasty (THA) aims at restoring the acetabular center of rotation and as much as possible the constitutional acetabular anteversion by using the transverse acetabular ligament (TAL) as a reference landmark. Also, the technique aims (1) at making personalized choice for the hip component design, (2) at defining the cup positioning, and (3) at sometimes considering additional spine surgery based on the assessment of the individual spine-hip relation. * KA techniques for hip replacements are relatively new, likely to become popular over time, and their true value remains to be determined.