Short- to Mid-Term Clinical Outcomes of Posterior-Stabilized Cementless Total Knee Arthroplasty with Trabecular Metal Components

OBJECTIVE: This study aimed to evaluate the short- to mid-term clinical results of posterior-stabilized trabecular metal total knee arthroplasty (TKA) with cementless fixation of all components and investigate the radiographic changes of tibial and patellar components and cut bone surfaces over time. METHODS: We retrospectively collected the data of 128 knees from 88 consecutive patients who had undergone initial TKA with NexGen LPS-Flex TM implants. A total of 66 knees from 45 patients (mean ± standard deviation age: 70.3 ± 7.5 years) met the selection criteria, which had been employed cementless fixation of all parts and at least 3 years of postoperative follow-up duration. Clinical evaluations included range of motion, conventional knee score, function score, postoperative complications, and revision. For radiological evaluations, the bone contact surface of each implant was divided into 7 zones for tibial component and 2 zones for patellar component. Each region was examined immediately after surgery, at 6 and 12 months, and then every year afterwards. RESULTS: The mean observation period of 45 subjects was 4.2 years. Adequate fixation of tibial components was maintained during follow-up, although the patellar components of 2 knees required revision after repeated falls. No loosening was observed in any implants. The initial gap in tibial components disappeared in all knees, and a reactive line remained in 4 knees. There were no revisions, except for 2 cases, which were ascribed to patellar component fracture caused by repeated falls. CONCLUSION: Cementless posterior-stabilized trabecular metal TKA appears to be a good surgical option. Longer-term examination for revision cases is required to validate our results.