Comparison Of Rotating-platform And Fixed-bearing Total Knee Arthroplasthy

Objective: The purpose of this study was to provide an evidence-based clinical andradiographic evaluation of a rotating-platform prosthesis in total knee arthroplasty (TKA)by comparing it with a fixed-bearing posterior stabilized prosthesis, and to provide thereference for clinical orthopedist in total knee arthroplasty that which prosthesis is better.Methods: From May2002to January2009, we performed a prospective randomizedstudy in the First Affiliated Hospital of Soochow University. According to inclusion andexclusion criteria,213patients(231knees) meet criteria. In the fixed-bearing group,107patients(115knees), including36men (39knees) and71women (76knees), wereperformed with Genesis Ⅱ posterior-stabilized fixed-bearing prosthesis (Smith-Nephew,USA). Their mean age was65.0±9.2years, and body mass index was27.2±2.2kg/m2. Inthe rotating-platform group,106patients(116knees),including31men (37knees) and75women (79knees) were performed with Gemini MKII (Link,Germany) rotating-platformprosthesis. Their mean age was62.3±7.7years, and body mass index was27.8±2.4kg/m2.The patients were scored using KSS Score for knees and Feller Score for Patella. Thepostoperative radiographic examinations included measuring the femoral angle, the tibialangle, the tibial posterior slope, the femoral flexion angle, the rate of patellar tilt orsubluxation and the tibia coverage in the coronal and sagittal plane. To observe andcompare the prevalence of lateral retinacular release, the postoperative ROM, thepostoperative radiographic examinations, the postoperative mean KSS score and Fellerscore between two groups. All dates were analyzed using SPSS16.0software, significantstatistical difference used P<0.05.Results: There was no statistical discrepancy in sample size, gender, age, body massindex(BMI), etiology of arthritis, preoperative range of motion, Feller Score and KSSscore between two groups (P>0.05). The mean length of follow-up was6.4years (range3to9years). There was no lining prolapse, spin out, osteolysis, prosthesis loosening or othercomplication occured in any of the patient. Six patients (116knees;5.2%) in the rotating-platform group had anterior knee pain (AKP)6months after surgery, comparedwith seven patients (115knees;6.1%) in the fixed-bearing group.This difference was nosignificant (P=0.76). Comparing the two groups, there was no significant difference in theprevalence of lateral retinacular release, the postoperative ROM, the postoperative meanKSS score and Feller score (P=0.71, P=0.15, P=0.08and P=0.22). In the follow-up X-rayshowed five patients (115knees;4.3%) in the fixed-bearing group while six patients (116knees;5.2%) in the rotating-platform group with patellar tilt or subluxation. The differencewas no significant (P=0.77). With the number available, we also could detected nosignificant difference between the two groups of patients with regard to measured femoralangle, tibial angle and tibial posterior slope (P=0.26, P=0.29, P=0.89and P=0.77).Conclusion: Regardless of performing the rotating-platform TKA or thefixed-bearing TKA, the patients would gained the improvement of and function,therebyimproved patient’s life quality and recovered daily activity. There was no significantdifference in early and mid-term results of the rotating-platform TKA and thefixed-bearing TKA. So far the fixed-bearing is not required to be completely replaced bythe rotating-platform. However, the long-term efficacy needs to be evaluated further.