Mid-Term to Long-Term Outcomes of Total Hip Arthroplasty Using a Cementless Trochanteric Sparing Short Stem Through Direct Anterior Approach: A Single-Center Study.

Background: Total hip arthroplasty (THA) is increasingly performed in younger patients, necessitating long-term femoral bone preservation. Metaphyseal engaging short stems offer potential benefits by reducing stress shielding and preserving bone stock. However, lacking long-term data in large quantities and younger patients in the literature led this study to assess mid-term to long-term outcome of these short stems. Methods: This retrospective study evaluated the long-term outcomes of 755 hips (667 patients) underwent THA using the Fitmore stem via a direct anterior approach. Clinical and radiographic assessments were conducted, and survival rates were determined using Kaplan-Meier analyses. Statistical analyses were performed to identify associations and predictors of stem revision. Results: The overall survival rate for the Fitmore stem was 92.11% at an average follow-up of 10 years. No revisions were performed due to aseptic loosening of the femoral component. Stem revisions were performed in 20 hips, primarily due to periprosthetic fractures followed by periprosthetic joint infections and recurrent dislocations. The clinical outcomes showed significant improvements in HHS, WOMAC Index, and VAS pain scores. Radiographic analysis revealed acceptable rates of complications, with minimal stem subsidence, no severe bone loss, and a low incidence of radiolucent lines and cortical hypertrophy. Conclusions: The Fitmore stem demonstrated favorable mid-term to long-term outcomes in terms of implant survival, functional scores, and radiographic assessments even in younger populations. The findings contribute to the existing body of knowledge on the Fitmore stem's efficacy and safety in preserving bone and achieving satisfactory clinical outcomes in THA. Level of evidence: IV.