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

Takashige Momose,1 Yukio Nakamura,2 Masaki Nakano,2 Takashi Maeda,1 Susumu Morioka,3 Atsushi Sobajima,1 Yukio Nakatsuchi,1 Jun Takahashi,2 Masashi Nawata1 1Department of Orthopaedic Surgery, Marunouchi Hospital, Matsumoto, Nagano, 390-8601, Japan; 2Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Nagano, 390-8621, Japan; 3Department of Orthopaedic Surgery, Chikuma Central Hospital, Chikuma, Nagano, 387– 8512, JapanCorrespondence: Yukio NakamuraDepartment of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, JapanTel +81-263-37-2659Fax +81-263-35-8844Email yxn14@aol.jpObjective: 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.Keywords: cementless fixation, short- to mid-term clinical outcomes, total knee arthroplasty, trabecular metal component