Tapered, Fluted, Titanium Stems in Revision Total Hip Arthroplasty

Establishing stable femoral component fixation in revision total hip arthroplasty (rTHA) remains challenging. Early monobloc tapered, fluted, titanium (TFT) designs were complicated by high rates of subsidence, while modular designs were complicated by taper corrosion and junctional fractures. Newer generation monobloc stems have been designed to minimize subsidence. Therefore, the aim of this study was to present the clinical and radio-graphic results of the most recent modular and monobloc TFT designs.

Patients undergoing rTHA in which TFT femoral stems were used, whether modular or monobloc, were included in this retrospective review. Included stems had the same design characteristics and were from the same manufacturer. The only difference was neck modularity. Radiographic analysis for stem subsidence was performed. Clinical outcomes including Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and re-revisions were collected. We examined survivorship for the endpoints of subsidence or re-revision for any reason.

Ninety-four (66 monobloc, 28 modular) hips met inclusion criteria, with a median follow-up of 25.9 months. Mean stem subsidence was 1.9±0.2 mm in the modular group and 2.1±0.3 mm in the monobloc group (P=.56), with 90 of 94 (95%) stems subsiding less than 5 mm. Twelve hips (13%) required re-revision with no difference in survival between the groups. HHS and WOMAC scores significantly improved from preoperative to last recorded follow-up in both groups (P≤.01).

Advances in implant design including spline geometry and more aggressive tapers in monobloc TFT femoral components offer encouraging clinical outcomes with an overall low risk of clinically significant subsidence. [Orthopedics. 2025;48(2):79-86.].