Sequentially Irradiated and Annealed Highly Cross-Linked Polyethylene: Clinical and Radiographic Outcomes in Total Knee Arthroplasty at 10-Year Follow-up.

Highly cross-linked polyethylene (HXLPE) has become the preferred bearing surface in total hip arthroplasty. However, its acceptance in total knee arthroplasty (TKA) has not been as robust because of concerns pertaining to wear and its impact on implant failure. Therefore, this multicenter study was purposed to evaluate the 10-year (1) radiographic outcomes; (2) complications; and (3) implant survivorship in patients with TKA receiving a sequentially irradiated and annealed HXLPE. A retrospective, multi-center study was performed on 139 patients (171 TKAs) who underwent primary TKA with HXLPE and possessed a minimum of 10-year follow-up. Radiographs were analyzed for radiolucencies along the implant-fixation interface using the Modern Knee Society Radiographic Evaluation System. Kaplan-Meier analysis determined implant survivorship when the end points were revision for polyethylene wear and polyethylene revision for any reason. Sixteen TKAs (9.9%) demonstrated periprosthetic linear radio-lucencies. Seventeen TKAs (9.9%) required additional surgeries, 9 (5.3%) of which were revisions, with 1 (0.6%) TKA requiring revision because of polyethylene wear. Other causes of revision included instability (1.8%), infection (1.6%), and arthrofibrosis (1.6%). The mean time to revision was 5.9 years (range, 0.1-11.1 years). Survivorship pertaining to polyethylene revision for wear was 99.4%, whereas all-cause polyethylene revision was 94.7%. This study in patients undergoing primary TKA using a second-generation HXLPE demonstrated excellent results with respect to polyethylene wear characteristics and strength with a 99.4% survivorship at 10 years. [Orthopedics. 2023;46(2):e111-e117.].

Comparison of outpatient versus inpatient total knee arthroplasty.

UNLABELLED: New protocols have been designed for outpatient total knee arthroplasty procedures, but concerns exist about the potential for increased complication rates. We compared the results of two selected matched cohorts of 64 patients who underwent total knee arthroplasty during the same time period. One cohort of patients, who had no severe medical conditions, lived within one hour of the office, and had help at home, followed an accelerated pathway in which they were discharged within 23 hours of surgery, and the other cohort followed a standard inpatient protocol, with a mean hospital stay of 2.3 days (range, 2-4 days). There were no perioperative complications in either cohort, and none of the patients who followed the outpatient protocol returned to the hospital for any reason. At a mean followup of 24 months (range, 12-41 months), the mean Knee Society knee scores of the outpatient and inpatient cohorts were 96 points (range, 67-100 points) and 95 points (range, 78-100 points), respectively. The mean Knee Society function scores were 89 points (range, 50-100 points) and 90 points (range, 60-100 points), respectively. We believe outpatient total knee arthroplasty may be a safe procedure in certain selected patients, with similar outcomes to a traditional protocol. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Total knee arthroplasty using cementless keels and cemented tibial trays: 10-year results.

The problem of early mechanical stability of cemented and cementless keels of the tibial component in total knee arthroplasty (TKA) is controversial. The purpose of this study was to assess clinical and radiographic outcomes of a cohort of 51 TKAs using a cemented platform with cementless keel fixation. At a mean follow-up of 10.4 years (range, 7 to 14 years), the mean Knee Society Score (KSS) was 93 points (range, 59 to 100 points), and the mean functional score was 73 points (range, 0 to 100 points). Only one patient demonstrated progressive tibial radiolucencies at 13.1 years follow-up, which resolved with a revision with an exchange of components. The results of this study suggest that a proximally cemented tibial tray with a press-fit keel TKA provides excellent mean 10-year outcomes.