Abstract
BACKGROUND: The majority of hip arthroplasties in the United States utilize cementless acetabular and femoral components. Despite their similarities, stem geometry can still differ. The purpose of this study is to compare the clinical results of two wedge-type stem designs. METHODS: A retrospective study of patients who underwent primary THA utilizing a direct anterior approach between January 2016 and January 2017. Two cohorts were established based on femoral stem design implanted. Descriptive patient characteristics and surgical and clinical data was extracted which included surgical time, length of stay (LOS), presence of pain (categorized as groin, hip, or thigh pain) at the latest follow-up, and revisions. Immediate postoperative radiographs were compared with the latest follow-up radiographs to assess limb length discrepancies, stem alignment, and stem subsidence. RESULTS: A total of 544 patients were included. 297 patients received the Group A stem (morphometric) and 247 patients received the Group B stem (flat-tapered). A significantly higher proportion of Group B stems subsided ≥3 mm and were in varus alignment than the Group A design. Additionally, a significantly greater number of patients who received the Group B stem reported postoperative hip and thigh pain. The logistic regression found that the Group B stem was 2.32 times more likely to subside ≥3 mm than the Group A stem. CONCLUSION: Our study suggests modestly improved radiographic and clinical outcomes and fewer instances of thigh pain, subsidence, and varus alignment in the patients who received the Group Ahip stem. Further studies are warranted to assess long-term significance.