Total Trapeziometacarpal Joint Arthroplasty Using the Uncemented HORUS® Prosthesis: Preliminary Results at 6-Month Follow-Up.

Background: Total trapeziometacarpal (TMC) joint arthroplasty has emerged as a surgical option for selected patients with TMC osteoarthritis. The HORUS® prosthesis (Evolutis, France) is a novel uncemented modular implant featuring a threaded screw-in trapezial cup coated with porous titanium and a PEXEL-E liner (vitamin E-infused cross-linked polyethylene) with a semi-retentive articulation. The purpose of this study was to report preliminary clinical and radiographic outcomes of total TMC joint arthroplasty using the uncemented HORUS® prosthesis at 6-month follow-up. Methods: Eleven patients (8 women, 3 men; mean age 63.6 ± 10.1 years) with Eaton-Littler stage II-III TMC osteoarthritis and at least 6 months of unsuccessful conservative treatment underwent total TMC joint arthroplasty using the HORUS® prosthesis. All procedures were performed by a single surgeon through a dorso-radial approach. Clinical outcomes were assessed preoperatively and at 15 days, 1, 3, and 6 months postoperatively using the Visual Analogue Scale (VAS), QuickDASH questionnaire, and Kapandji opposition score. Standardized radiographs were assessed at 1, 3, and 6 months for component position, periprosthetic radiolucency, cup migration/loosening, and stem subsidence. Results: One intraoperative trapezial fracture (1/11; 9.1%) required conversion to trapeziectomy with suspension arthroplasty; this patient was excluded from the prosthetic outcome analysis. In the remaining 10 patients, mean VAS decreased from 8.7 ± 1.1 preoperatively to 0.3 ± 0.7 at 6 months, mean QuickDASH decreased from 66.2 ± 11.3 to 14.5 ± 7.6, and mean Kapandji score increased from 5.8 ± 0.8 to 9.2 ± 0.6. One minor postoperative complication occurred (flexor tendinopathy of the third and fourth digits at 4 weeks). No dislocation, infection, or radiographic evidence of component migration, stem subsidence, or periprosthetic radiolucency was detected during the 6-month observation period. Conclusions: In this small preliminary series, the HORUS® prosthesis was associated with marked short-term improvements in pain, disability, and thumb opposition. These data should not be interpreted as evidence of long-term implant survival or a reduced risk of loosening because the cohort was small and follow-up was limited to 6 months. Larger comparative studies with longer follow-up are required to assess durability, implant-related complications, and revision risk.