Unicompartmental Knee Arthroplasty (UKA) has been indicated for inactive elderly patients over 60, but for young and active patients less than 60 years old, it has been regarded as a contraindication. The purpose of this study is to evaluate the usefulness of UKA performed on young Asian patients under 60 years of age by analyzing clinical outcomes, complications and survival rate. The subjects were 82 cases, which were followed up for at least 5 years (from 5 to 12 years). Only Oxford phase III® (Biomet Orthopedics, Inc, Warsaw, USA) prosthesis was used for all cases. The clinical evaluation was done by the range of motion, Knee society score (KSS), WOMAC score. The radiographic evaluation was performed on weight bearing long-leg radiographs, AP and lateral view of the knee and skyline view of the patella. The survival rate was estimated by Kaplan-Meier survival analysis.Purpose
Materials and Methods
Despite the excellent clinical success of total knee arthroplasty (TAK), controversy remains concerning whether or not to resurface the patella. This has led to a number of randomized controlled trials. Randomized controlled trials constitute the most reliable source of evidence for the evaluation of the efficacy of a potential intervention. But most of these studies include all degree of osteoarthritis of the patellofemoral joint. So we did this prospective study to compare clinical and radiological outcomes after TKA with or without patellar resurfacing in patients with grade IV osteoarthritis on patellofemoral joint. 123 cases (93 patients) with Kellgren-Lawrence grade IV osteoarthritis on patellofemoral joint were enrolled for this study. At the operating room, they were randomly assigned to undergo patella resurfacing (62 cases) or patella retention (61 cases). Among them, 114 cases that could be followed for more than 2 years were included in this study (resurfacing group; 59 cases, retention group; 55 cases). When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. Preoperative and postoperative clinical outcomes were evaluated and compared regarding the Hospital for Special Surgery Patellar (HSSP) score (total 100 point; anterior knee pain, functional limitation, tenderness, crepitus, Q-strength). We also compared Hospital for Special Surgery (HSS) and WOMAC scores, and range of motion (ROM). We also compared radiological outcomes at the final follow up, with regards to mechanical axis of the lower limb, patella tilt and patella congruence angle between two groups.Background
Materials and Methods
Knee kinematics are altered by total knee arthroplasty (TKA) both intentionally and unintentionally. Knowledge of how and why kinematics change may improve patient outcome and satisfaction through improved implant design, implant placement or through rehabilitation. In the present study we imaged and compared the 6 degree-of-freedom (DOF) patellofemoral (PF) and tibiofemoral (TF) kinematics of 9 pre-TKA subjects to the kinematics of 15 post-TKA subjects (Zimmer NexGen LPS implants) using a novel sequential-biplanar radiographic protocol that allowed imaging the postoperative patellofemoral joint under weightbearing throughout the range of motion, which has not been done previously to our knowledge. There were clear, statistically significant differences between the pre-TKA and post-TKA kinematics: for the TF joint, the tibia was more posterior and inferior (max 20 mm and 15 mm, respectively) in the post-TKA group compared to the pre-TKA group (p<0.001), and had neutral alignment in the post-TKA group compared to varus alignment (max 9°) in the pre-TKA group (p<0.001). For the PF joint, the patella was shifted more posteriorly and medially, and tilted more medially in the post-TKA group compared to the pre-TKA group (p<0.001). There were no significant differences in PF superior/inferior translation and flexion/extension (p>0.5). Both groups showed differences from normal kinematics, based on the literature. The kinematic differences are likely due to a combination of surgical, implant and patient factors. To investigate this further, we imaged the 9 pre-TKA subjects a minimum one year after their surgery; analysis of these data is in progress. Computed tomography (CT) scans and quality of life surveys were also taken before and after surgery. By comparing the preoperative and postoperative kinematics and shape for the same subjects, and analysing the interrelationships amongst these, we aim to determine if a different implant shape or different component positioning could create more normal kinematics, resulting in a better clinical outcome.
