SHORT TERM COMPARISON OF CLINIC RADIOGRAPHIC RESULTS OF TOTAL HIP REPLACEMENT WITH SHORT FEMORAL STEM IN OBESE AND NON-OBESE YOUNG PATIENTS. SINGLE CENTER PROSPECTIVE PILOT STUDY.

Abstract

Background: Total hip arthroplasty (THA) is a highly successful orthopedic procedure increasingly performed on younger, obese patients due to its ability to improve functional outcomes and quality of life. However, obesity presents challenges related to implant selection and long-term outcomes, particularly with the use of short femoral stems. While short stems offer benefits such as bone preservation and reduced stress shielding, their reliability in obese patients remains underreported.

Aim: Compare functional and radiographic results of THA in obese versus non obese young patients.

Methods: This single-center case-control study evaluated clinical and radiographic outcomes of obese patients (BMI ≥30 kg/m²) undergoing primary uncemented THA with short femoral stems. A total of 120 patients (60 obese, 60 nonobese) were enrolled, matched 1:1. Outcomes assessed included surgical parameters, Harris Hip Score (HHS), Roles and Maudsley satisfaction score, and radiographic implant evaluations at a minimum follow-up of two years. Statistical comparisons were performed using SPSS, with a significant threshold of p<0.05.

Results: Operative times and incision lengths were modestly longer in obese patients (p<0.05). Mean postoperative HHS improved significantly in both groups, with scores of 91±3.7 (obese) and 93±2.5 (nonobese). Radiographic analysis showed excellent implant positioning, with all components within the Lewinnek safe zone. Minor radiolucencies and subsidence (≤2 mm) were observed in a small subset of obese patients but were clinically insignificant. Complication rates were low and comparable between groups, with one superficial infection in the obese group and one deep venous thrombosis in the nonobese group.

Conclusions: Short femoral stems in uncemented THA demonstrate safe and effective performance in obese patients, yielding clinical and radiographic outcomes comparable to nonobese patients. Short stems provide the added advantage of bone preservation, which is critical for revision surgery in younger, obese populations. Larger studies with longer follow-up are needed to validate these findings and assess long-term implant survival.