BACKGROUND:Mobile bearing (MB) total knee design has been advocated as a means to enhance the functional characteristics and decrease the wear rates of condylar total knee arthroplasty (TKA). However, it is unclear if these designs achieve these goals. QUESTIONS/PURPOSES: We asked whether function of patients or survivorship would be greater or complications would be lesser in groups of patients with MB compared with fixed bearing (FB) TKA. We also sought to describe retrieval findings. METHODS: We randomized 507 primary TKAs in 416 eligible patients to receive MB (n = 252) orFB (n = 255) devices from November 2001 to August 2007 (Investigational Device Exemption G000180, ClinicalTrials.gov registration number NCT00946075). Patients were blinded to treatment allocation. WOMAC Index, SF-12Health Survey, knee range of motion, and Knee Society scores were collected and compared preoperatively and at 6, 12, and 24 months postoperatively. We recorded device failures and complications until October 2009. Kaplan-Meier survivorship was compared using the log rank test. Twelve retrieved MB devices underwent pathologic analysis. The minimum postoperative time was 2.2 years (mean, 5.9 years; range, 2.2-7.9 years). RESULTS: We found no differences in mean clinical assessment scores or mean score changes from baseline at any postoperative interval through 2 postoperative years. Nineteen of the 252 MB and 13 of the 255 FB knees hadundergone revision of any component. Estimated survival at 6 postoperative years was similar for the two devices: 90.1% (95% confidence interval [CI], 84.1-93.9) for MB and 94.2% (95% CI, 90.1-96.6) for FB. Two MB and no FB tibial components were revised for loosening. There was one case of MB insert dislocation. Retrieved MB devices demonstrated no unexpected wear or mechanical device failures. CONCLUSION: We found no evidence of functional advantage of the MB design. Survivorship was similar, although the study is limited by short duration of followup.
RCT Entities:
BACKGROUND: Mobile bearing (MB) total knee design has been advocated as a means to enhance the functional characteristics and decrease the wear rates of condylar total knee arthroplasty (TKA). However, it is unclear if these designs achieve these goals. QUESTIONS/PURPOSES: We asked whether function of patients or survivorship would be greater or complications would be lesser in groups of patients with MB compared with fixed bearing (FB) TKA. We also sought to describe retrieval findings. METHODS: We randomized 507 primary TKAs in 416 eligible patients to receive MB (n = 252) or FB (n = 255) devices from November 2001 to August 2007 (Investigational Device Exemption G000180, ClinicalTrials.gov registration number NCT00946075). Patients were blinded to treatment allocation. WOMAC Index, SF-12 Health Survey, knee range of motion, and Knee Society scores were collected and compared preoperatively and at 6, 12, and 24 months postoperatively. We recorded device failures and complications until October 2009. Kaplan-Meier survivorship was compared using the log rank test. Twelve retrieved MB devices underwent pathologic analysis. The minimum postoperative time was 2.2 years (mean, 5.9 years; range, 2.2-7.9 years). RESULTS: We found no differences in mean clinical assessment scores or mean score changes from baseline at any postoperative interval through 2 postoperative years. Nineteen of the 252 MB and 13 of the 255 FB knees had undergone revision of any component. Estimated survival at 6 postoperative years was similar for the two devices: 90.1% (95% confidence interval [CI], 84.1-93.9) for MB and 94.2% (95% CI, 90.1-96.6) for FB. Two MB and no FB tibial components were revised for loosening. There was one case of MB insert dislocation. Retrieved MB devices demonstrated no unexpected wear or mechanical device failures. CONCLUSION: We found no evidence of functional advantage of the MB design. Survivorship was similar, although the study is limited by short duration of followup.
Authors: Moon Seok Park; Sung Ju Kim; Chin Youb Chung; In Ho Choi; Sang Hyeong Lee; Kyoung Min Lee Journal: J Bone Joint Surg Am Date: 2010-07-21 Impact factor: 5.284
Authors: A J Price; J L Rees; D Beard; E Juszczak; S Carter; S White; R de Steiger; C A F Dodd; M Gibbons; P McLardy-Smith; J W Goodfellow; D W Murray Journal: J Bone Joint Surg Br Date: 2003-01
Authors: Stephen Graves; Art Sedrakyan; Valborg Baste; Terence J Gioe; Robert Namba; Olga Martínez Cruz; Susanna Stea; Elizabeth Paxton; Samprit Banerjee; Abby J Isaacs; Otto Robertsson Journal: J Bone Joint Surg Am Date: 2014-12-17 Impact factor: 5.284
Authors: B L Fransen; D C van Duijvenbode; M J M Hoozemans; B J Burger Journal: Knee Surg Sports Traumatol Arthrosc Date: 2016-06-20 Impact factor: 4.342
Authors: Koen T Van Hamersveld; Perla J Marang-Van De Mheen; Huub J L Van Der Heide; Henrica M J Van Der Linden-Van Der Zwaag; Edward R Valstar; Rob G H H Nelissen Journal: Acta Orthop Date: 2018-02-16 Impact factor: 3.717