Published online Aug 18, 2021. doi: 10.5312/wjo.v12.i8.534
Peer-review started: February 14, 2021
First decision: May 3, 2021
Revised: May 10, 2021
Accepted: July 20, 2021
Article in press: July 20, 2021
Published online: August 18, 2021
Processing time: 178 Days and 5.2 Hours
Short stems in total hip arthroplasty (THA) are becoming increasingly popular. In Germany, already 10.4% of all primary THAs are performed using a cementless short stem. The concept of modern, calcar-guided, short stems aims for an individualized reconstruction of the hip anatomy by following the calcar of the femoral neck, a bone- and soft-tissue-sparing implantation technique, and physiological loading. The stem design uses either metaphyseal fixation alone or additional diaphyseal anchoring, depending on the stem alignment and indication. These individualized anchorage types increase the potential indications for the safe use of a short stem. The design features may account for potential advantages of current short stem implants compared with earlier short-stem designs, particularly in cases of reduced bone quality or osteonecrosis of the femoral head and femoral neck fractures. The implantation technique, however, requires distinct knowledge regarding the characteristics of varus and valgus positioning, with the potential for clinical consequences. A learning curve for surgeons new to this technique must be taken into account. Cortical contact with the distal lateral cortex appears to be crucial to provide sufficient primary stability, and the use of intraoperative imaging to identify “undersizing” is highly recommended. Current results of several national registries indicate that calcar-guided short stems are among the most successful implants in terms of mid-term survivorship. However, long-term data remain scarce. This review introduces the characteristics of calcar-guided short-stem THA and summarizes the current evidence.
Core Tip: Modern calcar-guided short stems offer numerous advantages compared with conventional total hip arthroplasty (THA). The broad potential to reconstruct the individual hip geometry, the reduced proximal bone remodeling, and the simplified soft-tissue-sparing implantation represent true accomplishments in THA. Mid-term data indicates encouraging outcomes and excellent implant survival. If long-term data confirm these promising results, chances are good that calcar-guided short stems will become the future standard in THA.