Comparative mid-term evaluation of unilateral and bilateral total knee arthroplasty utilizing metal-backed components: An assessment of functional and clinical outcomes

This prospective, post-marketing surveillance (PMS) study (Freedom 400) aimed to evaluate the clinical and functional outcomes of both unilateral and bilateral total knee arthroplasty (TKA) utilizing cruciate retaining/posterior stabilized (CR/PS) implants with metal-backed components (MBC). Between November 2016 to January 2019, 408 patients underwent either unilateral or bilateral TKA at ten centers across India. Patients with primary end-stage osteoarthritis (OA) or inflammatory arthritis were included whereas, revision TKA patients were excluded from the study. Primary endpoints were 3-year implant survivorship and revision rates, with secondary endpoints including range of motion (ROM), Knee Society Score (KSS), and quality of life (QoL) assessed through WOMAC and SF-36 at 6 weeks, 6 months, 1- and 3 years. The study comprised 242 unilateral and 166 bilateral TKA patients, with an average age of 65.13 ± 8.35 and 64.34 ± 7.25 years, respectively. Both groups exhibited a mean body mass index of 27.13 ± 4.73 kg/m2 and 27.80 ± 4.41 kg/m2. Female patients dominated the groups: 78.1 % and 86.75 % respectively, and the primary diagnosis was OA: 97.11 % and 96.39 %, respectively. Significant ROM improvement was observed in both groups (p