Postoperative Radiographic Assessment of the Vega Posterior-Stabilized TKA.

Abstract

Different biomechanical designs are incorporated into various total knee arthroplasty (TKA) implants. The posterior-stabilized prosthesis design utilizes a polyethylene post and femoral cam in place of the posterior cruciate ligament. This produces a more stable component interface, increased range of motion, and potentially a less technical procedure. This study aimed to assess the short-term (>2 year) outcomes associated with the Vega System posterior-stabilized knee prosthesis (Aesculap Implant Systems, Center Valley, Pennsylvania) based on postoperative radiographs using the Knee Society Roentgenographic Evaluation and Scoring System (KSRESS). Thirty-seven TKA patients who had received the Vega posterior-stabilized knee prosthesis and had postoperative radiographs at each follow-up for a minimum of 2 years were enrolled, retrospectively. Two independent observers evaluated the radiographs using KSRESS. Descriptive statistics were used to analyze the data. The average age and body mass index of patients enrolled was 67 years (range, 51-89 years) and 38.5 kg/m(2) (range, 21.2-54 kg/m(2)), respectively. Patients had radiographic follow-up for an average of 36 months (range, 24-58 months). Comparison between first and last available postoperative radiographs revealed a stable femoral and tibial interface with no significant change in prosthesis alignment over the follow-up period. Assessment of the short-term survivorship of the Vega posterior-stabilized prosthesis using KSRESS revealed no significant change in alignment after 2 years of follow-up; however, mid- to long-term studies assessing this junction are needed. A future prospective study using KSRESS in combination with clinical follow-up is recommended to allow comparison of the Vega posterior-stabilized to other prostheses. [Orthopedics. 2016; 39(3):S56-S60.].