Mobile- and fixed-bearing total knee arthroplasty for knee osteoarthritis Comparisons of early clinical outcomes
- VernacularTitle:活动衬垫和固定衬垫全膝关节置换治疗膝骨性关节炎的早期临床结果比较
- Author:
Zijian LI
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2008;12(48):9589-9593
- CountryChina
- Language:Chinese
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Abstract:
BACKGROUND: Although mobile bearing knee prosthesis exhibits good movement and low wear rate in vitro studies,its clinical effect in vivo is still contraversial. OBJECTIVE: To compare and observe the range of motion and clinical outcomes of mobile bearing knee prosthesis and fixed bearing knee prothesis at least 1 year after operation. DESIGN,TIME AND SETTING: A randomized controlled observation. The experiment was performed at the Joint Reconstruction Center,Seoul National University Bundang Hospital,Seoul,Korea between November 2003 and July 2006. PARTICIPANTS: Four hundrend and eighty-eight patients (669 knees) with knee osteoarthritis undergoing total knee arthroplasty (TKA) were selected,of them 244 (341 knees) were treated with fixed bearing knee prothesis and 244 (328knees) with mobile bearing knee prosthesis.METHODS: The surgery was performed by the same physician (TK Kim). With patellar medial approach,the patella was not turned over,but dislocated laterally to expose the bone. Space measurer was used to expand and measure the Space. According to the measurements,soft tissues were released and balanced until the flexion gap was within 3-4 mm more than extension gap or 1-2 mm extension gap more than flexion gap. For varus knees,2-3 mm larger lateral gap was accepted. In all cases,the patella was resuffaced,and implant fixation was carried out with cement.MAIN OUTCOME MEASURES: Degrees of flexion contracture and maximum flexion angle were measured with a goniometer. The knee pain and functional status were evaluated by American Knee Society (AKS) scores,Patellofemoral scores,Western Ontario McMaster Universities Osteoarthritis Index scales (WOMAC) and SF-36 systems.RESULTS: There was no significant difference between two groups in terms of sex,age,body height,body mass and body mass index. No differences wre found in postoperative socres of Patellofemoral scores,WOMAC and SF-36systems (P>0.05). The mean AKS scores of fixed bearing knee prothesis group were higher than mobile group (48.5±3.2,47.5±4.8,P=0.010). The flexion defomity of two groups was significantly corrected following surgery (P=0.341). No differences were found in terms of range of motion (P=0.412) and knee function (P>0.05).CONCLUSION: The mobile bearing design has no advantages in postoperative range of motion,pain relief and knee function relative to fixed bearing design. Surgical technique is critical to achieve good clinical outcomes.
