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Uncemented Tantalum Monoblock Tibial Fixation for Total Knee Arthroplasty in Patients Less Than 60 Years of Age: Mean 10-Year Follow-up

Background: Although tibial component loosening has been considered a concern after total knee arthroplasty without cement, such implants have been used in younger patients because of the potential for ingrowth and preservation of bone stock. However, mid-term and long-term studies of modern uncemented implants are lacking. We previously reported promising prospective 5-year outcomes after using an uncemented porous tantalum tibial component in patients who underwent surgery before the age of 60 years. The purpose of this study was to determine clinical and radiographic implant survivorship at 10 years in this large series of young patients. Methods: The original cohort included 79 patients (96 knees) who were <60 years old at the time of surgery. All procedures were performed with an uncemented, posterior-stabilized femoral component and a porous tantalum monoblock tibial component by 1 high-volume arthroplasty surgeon at a single institution. Patients were followed prospectively. The Knee Society Score (KSS), radiographic findings, and any complications or revisions were recorded. Results: At the latest follow-up, 76% (60) of the 79 patients (74% [71] of the 96 knees) were available for evaluation or had undergone revision (n = 6); 7 patients had died with the implants in place, and 12 patients were lost to follow-up. The average follow-up for the available implants was 10 years (range, 8 to 12 years). There were no progressive radiolucencies on radiographic review. The mean functional KSS was 68 points (range, 0 to 100 points). All revisions were for reasons unrelated to tibial fixation: femoral component loosening (1), stiffness (1), pain and swelling (2), and instability (2). The all-cause revision rate was 6% (6 of 96 knees). Conclusions: Uncemented porous tantalum monoblock tibial components provided reliable fixation, excellent radiographic findings, and satisfactory functional outcomes at a mean of 10 years postoperatively. We identified no cases of tibial component loosening. These promising clinical and radiographic results support the use of uncemented tibial components. Such implants may produce well-integrated, durable long-term constructs in young patients. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.