Noboru Shimada1, Masataka Deie2, Kazuhiko Hirata1, Yasuhiko Hiate1, Naoya Orita1, Daisuke Iwaki1, Yoshihiro Ito1, Hiroaki Kimura3, Evangelos Pappas4, Mitsuo Ochi5. 1. Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan. 2. Institute of Biomedical and Health Sciences, Graduate School of Health Sciences, Hiroshima University, Hiroshima, Japan. snm3@hiroshima-u.ac.jp. 3. Department of Rehabilitation Medicine, Hiroshima University Hospital, Hiroshima, Japan. 4. Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia. 5. Department of Orthopedic Surgery, Hiroshima University, Hiroshima, Japan.
Abstract
PURPOSE: In total knee arthroplasty (TKA), dynamic knee loading may loosen the artificial joint and bone or cause polyethylene wear after prolonged use. TKA decreases knee adduction moment at 6 months, but this effect is lost by 1 year post-operatively. However, lateral thrust after TKA has not been clarified. We hypothesized that like knee adduction moment, lateral thrust would return to baseline levels by 1 year post-operatively. METHODS: Participants were 15 patients who underwent TKA for medial knee OA. Japanese Orthopaedic Association (JOA) score, numeric rating scale, and gait analysis (measurement of peak knee adduction moment, knee varus angle at peak knee adduction moment, lateral thrust, and gait speed) were performed preoperatively (baseline) and 3 weeks, 3 and 6 months, and 1 year post-operatively. RESULTS: JOA score improved from 55 ± 9.8 to 78 ± 12.1 at 1 year post-operatively, and pain decreased significantly from baseline at each follow-up (p < 0.001). Significant increases in gait speed were observed at 6 months and 1 year (p < 0.001). Peak knee adduction moment during stance phase was significantly lower at 3 weeks, 3 months, and 6 months compared to baseline (p < 0.05), but no significant changes were seen at 1 year. Knee varus at peak knee adduction moment did not differ significantly between any measurement points, while lateral thrust was decreased at 6 months and 1 year compared to baseline (p < 0.05). CONCLUSIONS: Temporal courses of changes up to 1 year after TKA differed between knee adduction moment and lateral thrust, so our hypothesis was rejected. LEVEL OF EVIDENCE: IV.
PURPOSE: In total knee arthroplasty (TKA), dynamic knee loading may loosen the artificial joint and bone or cause polyethylene wear after prolonged use. TKA decreases knee adduction moment at 6 months, but this effect is lost by 1 year post-operatively. However, lateral thrust after TKA has not been clarified. We hypothesized that like knee adduction moment, lateral thrust would return to baseline levels by 1 year post-operatively. METHODS:Participants were 15 patients who underwent TKA for medial knee OA. Japanese Orthopaedic Association (JOA) score, numeric rating scale, and gait analysis (measurement of peak knee adduction moment, knee varus angle at peak knee adduction moment, lateral thrust, and gait speed) were performed preoperatively (baseline) and 3 weeks, 3 and 6 months, and 1 year post-operatively. RESULTS: JOA score improved from 55 ± 9.8 to 78 ± 12.1 at 1 year post-operatively, and pain decreased significantly from baseline at each follow-up (p < 0.001). Significant increases in gait speed were observed at 6 months and 1 year (p < 0.001). Peak knee adduction moment during stance phase was significantly lower at 3 weeks, 3 months, and 6 months compared to baseline (p < 0.05), but no significant changes were seen at 1 year. Knee varus at peak knee adduction moment did not differ significantly between any measurement points, while lateral thrust was decreased at 6 months and 1 year compared to baseline (p < 0.05). CONCLUSIONS: Temporal courses of changes up to 1 year after TKA differed between knee adduction moment and lateral thrust, so our hypothesis was rejected. LEVEL OF EVIDENCE: IV.
Authors: Karl F Orishimo; Ian J Kremenic; Ajit J Deshmukh; Stephen J Nicholas; Jose A Rodriguez Journal: Clin Orthop Relat Res Date: 2011-11-29 Impact factor: 4.176