Minimum 2-Year Outcomes Of A Modern Monoblock Titanium Fluted Tapered Revision Stem For Complex Primary and Revision Total Hip Arthroplasty.

INTRODUCTION: Modular titanium fluted tapered (TFT) stems have demonstrated excellent clinical success for femoral revision total hip arthroplasty (THA) surgery. This aim study reports the short-term outcomes of a novel modern monoblock TFT stem used for revision and complex primary THA with a minimum of 2 years of follow-up.

METHODS: We identified 126 patients who received a single monoblock TFT stem; 26 patients for complex THA (failed fracture fixation) and 100 patients for revision THA. The reasons for revision THA included 40 for previous periprosthetic joint infection (PJI), 42 for aseptic loosening, 9 for trunnionosis, and 9 for periprosthetic fractures. The Paprosky grading for femoral bone loss at the time of surgery and the measured subsidence of femoral stems at 3-month follow-up were determined. We evaluated the number and indications for re-operations.

RESULTS: The mean time from surgery was 3.9 years (range, 2.0 to 6.9). A paired t-test analysis showed significant improvement from pre-operative versus post-operative clinical outcome scores (P < 0.001) for Harris Hip Score (38.76 +/- 15.24 versus 83.42 +/- 15.38), Western Ontario and McMaster Universities Arthritis Index (45.6 ± 19.0 versus 69.9 ± 21.3), Veterans RAND 12 Item Health Survey (VR12) Physical component (31.7 ± 8.1 versus 37.8 ± 11.3), and VR12 Mental component (48.2 ± 12.2 versus 51.6 ± 12.5). The Paprosky grading for femoral bone loss was Grade 1 (3.9%), Grade 2 (35.7%), Grade 3A (47.6%), Grade 3B (11.1%), and Grade 4 (1.6%) cases. There were 18 re-operations (14.7%), with 13 for PJI (7 treated with implant retention, 6 treated with a two-stage revision), 4 for instability, and one for acetabular aseptic loosening. There were no aseptic failures of the stem.

CONCLUSION: This novel modern monoblock TFT stem provided reliable femoral fixation and has increasingly supplanted the use of modular TFT stems for complex primary and revision surgery in our institution.