The alternative kinematic alignment (KA) technique for total knee arthroplasty (TKA) aims at restoring the native joint line orientation and laxity of the knee. The goal is to generate a more physiological prosthetic knee enabling higher functional performance and satisfaction for the patient. KA TKA have only been reported so far with cruciate retaining and posterior-stabilised designs. Similarly, medial pivot design for TKA has been recently developed to enable more natural knee kinematics and antero-posterior stability. The superiority of KA technique and medial pivot implant design is still controversial when compared to current practice. Our study aims to assess the value of KA TKA when performed with medial pivot implants. We conducted a retrospectively matched case-control study. Clinical data was prospectively collected on patients as part of an ongoing ODEP study. Thirty-three non-selected consecutive KA TKAs performed by the lead author were matched to a control group of 33 measured resection with mechanically aligned (MA) TKAs performed by other consultant surgeons. Patients were matched for sex, age, BMI and pre-operative Oxford Knee Score (OKS). Pre-operative median OKS was 21 points (max 48), mean age was 69, mean BMI 31, and there were 21 female patients in both arms. The medial pivot GMK Sphere implant (Medacta, Switzerland) was used in all cases. OKS and EQ-5D scores were measured pre-operatively and at 1-year post-op. Patient outcome satisfaction scores were assessed at 1-year follow-up using a visual analogic scale (VAS). Pre- and post-operative knee radiographs were analysed using TraumaCad software.Introduction
Methods
Historically, the clinical performance of novel implants was usually reported by designer surgeons who were the first to acquire clinical data. Regional and national registries now provide rapid access to survival data on new implants and drive ODEP ratings. To assess implant performance, clinical and radiological data is required in addition to implant survival. Prospective, multi-surgeon, multi-centre assessments have been advocated as the most meaningful. We report the preliminary results of such a study for the MiniHip™femoral component and Trinity™ acetabular component (Corin Ltd, UK). As part of a non-designer, multi-surgeon, multi-centre prospective surveillance study to assess the MiniHip™stem and Trinity™ cup, 535 operations on 490 patients were undertaken. At surgery, the average age and BMI of the study group was 58.2 years (range 21 to 76 years) and 27.9 (range 16.3 to 43.4) respectively. Clinical (Harris Hip Score, HHS) and radiological review have been obtained at 6 months, 3 and 5 years. Postal Oxford Hip Score (OHS) and EuroQol- 5D (EQ5D) score have been obtained at 6 months and annually thereafter. To date, 23 study subjects have withdrawn or lost contact, 11 have died, and 9 have undergone revision surgery. By the end of March 2018, 6 month, 1, 2, 3, 4, and 5 year data had been obtained for 511, 445, 427, 376, 296 and 198 subjects respectively.INTRODUCTION
METHODS
