LAUSR

1. The purpose of this study was to report the rate of complications using a short-stem implanted through the direct anterior approach (DAA) and to evaluate mid-term clinical and radiological results focusing on femoral stem fixation. The short stem used in the study, AMIStem-H® (Medacta, Switzerland), is a cementless short femoral stem with a rectangular triple-tapered design and hydroxyapatite (HA) coating. We have used short stems for DAA surgery for many years and have achieved satisfactory results in clinical practice. There is different from the use of AMIStem-H® (Medacta, Switzerland). The short stem we used is Triloc stems (DePuy Company, USA) which has featuring GRIPTIONTM Coating. The stem is similar to conventional, proximally coated tapered stems but with a shorter distal taper to avoid stress-shielding, often extending only to the proximal aspect of the diaphysis. This type of stem is designed for proximal stress transfer [2]. Ulivi et al. [3] examined 163 Tri-Lock Bone Preservation stems (DePuy) with a minimum seven year follow-up and found no cases of aseptic loosening and no progressive radiolucent lines or periprosthetic osteolysis, demonstrating adequate radiographic osseointegration, with one revision for dislocation, and two patients reported thigh pain. In DAA surgery, the clinical effects of different designs of short stems are quite different. Whether AMIStem-H® is the best option for DAA surgery remains to be discussed. 2. Hip and knee joints in the USA in 2013 (The American Association of Hip and Knee Surgeons, AAHKS) recommended a bodymass index > 40 kg/m. Of patients whose total hip arthroplasty should not be used, this recommendation also applies to DAA-THA. But in this study, 13 patients with BMI > 40 kg/m. And the study did not really address the impact of obesity on the experimental conclusions. 3. All procedures were not performed by a single surgeon, and the article does not describe whether different surgeons performed direct anterior total hip arthroplasty in the same way. This would add uncertainty to the research.