T B Birmingham1, R Moyer2, K Leitch3, B Chesworth4, D Bryant5, K Willits6, R Litchfield7, P J Fowler8, J R Giffin9. 1. School of Physical Therapy, Faculty of Health Sciences, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: tbirming@uwo.ca. 2. School of Physiotherapy, Faculty of Health Professions, Dalhousie University, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: rebecca.moyer@dal.ca. 3. Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: kleitch@uwo.ca. 4. School of Physical Therapy, Faculty of Health Sciences, University of Western Ontario, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: bcheswor@uwo.ca. 5. School of Physical Therapy, Faculty of Health Sciences, University of Western Ontario, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: dianne.bryant@uwo.ca. 6. Department of Surgery, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: kwillit@uwo.ca. 7. Department of Surgery, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: rlitchf@uwo.ca. 8. Department of Surgery, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: fowler@uwo.ca. 9. Department of Surgery, Schulich School of Medicine and Dentistry, University of Western Ontario, Canada; Fowler Kennedy Sport Medicine Clinic, London Health Sciences Centre, Ontario, Canada; Bone and Joint Institute, University of Western Ontario, Canada. Electronic address: rgiffin@uwo.ca.
Abstract
OBJECTIVE: To evaluate 5-year outcomes after lower limb realignment and test the hypothesis that surgery-induced changes in selected biomechanical risk factors for medial knee osteoarthritis (OA) are associated with clinically important improvements. DESIGN: We prospectively evaluated patient-reported outcomes, full-limb standing radiographs and gait biomechanics before, 6 months (surgery-induced change) and 5 years after medial opening wedge high tibial osteotomy (HTO) in 170 patients (46.4 ± 8.9 years, 135 males) with knee OA and varus alignment. Logistic regression tested the associations of 6-month changes in mechanical axis angle and knee adduction moment with achieving an increase of ≥10 points in the Knee injury and Osteoarthritis Outcome Score (KOOS)4 at 5 years, with and without adjusting for covariates. Gait data were also compared to existing data from healthy controls. RESULTS: Mean 5-year changes (95% confidence interval (CI)) were: KOOS4: +14.2 (10.8, 17.6); mechanical axis angle: +8.21° (7.58, 8.83); knee adduction moment: -1.49 %BW*Ht (-1.35, -1.63). The postoperative knee adduction moments were typically lower than values for healthy controls. When divided into quartiles, although all strata improved significantly, patients with reductions in knee adduction moment of 1.14-1.74 %BW*Ht (neither largest nor smallest changes) had highest 5-year KOOS4 scores. The 6-month change in knee adduction moment (odds ratios (OR) = 0.38; 95% CI: 0.22, 0.67), preoperative KOOS4 (OR = 0.96; 95% CI: 0.94, 0.99) and preoperative medial tibiofemoral narrowing grade (OR = 0.62; 95% CI: 0.37, 1.00) were negatively associated with having a 5-year clinically important improvement (C-statistic = 0.70). CONCLUSIONS: Substantial improvements in biomechanical risk factors and patient-reported outcomes are observed 5 years after medial opening wedge HTO. The surgery-induced change in load distribution during walking is significantly associated with long-term clinically important improvement.
OBJECTIVE: To evaluate 5-year outcomes after lower limb realignment and test the hypothesis that surgery-induced changes in selected biomechanical risk factors for medial knee osteoarthritis (OA) are associated with clinically important improvements. DESIGN: We prospectively evaluated patient-reported outcomes, full-limb standing radiographs and gait biomechanics before, 6 months (surgery-induced change) and 5 years after medial opening wedge high tibial osteotomy (HTO) in 170 patients (46.4 ± 8.9 years, 135 males) with knee OA and varus alignment. Logistic regression tested the associations of 6-month changes in mechanical axis angle and knee adduction moment with achieving an increase of ≥10 points in the Knee injury and Osteoarthritis Outcome Score (KOOS)4 at 5 years, with and without adjusting for covariates. Gait data were also compared to existing data from healthy controls. RESULTS: Mean 5-year changes (95% confidence interval (CI)) were: KOOS4: +14.2 (10.8, 17.6); mechanical axis angle: +8.21° (7.58, 8.83); knee adduction moment: -1.49 %BW*Ht (-1.35, -1.63). The postoperative knee adduction moments were typically lower than values for healthy controls. When divided into quartiles, although all strata improved significantly, patients with reductions in knee adduction moment of 1.14-1.74 %BW*Ht (neither largest nor smallest changes) had highest 5-year KOOS4 scores. The 6-month change in knee adduction moment (odds ratios (OR) = 0.38; 95% CI: 0.22, 0.67), preoperative KOOS4 (OR = 0.96; 95% CI: 0.94, 0.99) and preoperative medial tibiofemoral narrowing grade (OR = 0.62; 95% CI: 0.37, 1.00) were negatively associated with having a 5-year clinically important improvement (C-statistic = 0.70). CONCLUSIONS: Substantial improvements in biomechanical risk factors and patient-reported outcomes are observed 5 years after medial opening wedge HTO. The surgery-induced change in load distribution during walking is significantly associated with long-term clinically important improvement.
Authors: Codie A Primeau; Trevor B Birmingham; Kristyn M Leitch; Kevin R Willits; Robert B Litchfield; Peter J Fowler; Jacquelyn D Marsh; Bert M Chesworth; Stephanie N Dixon; Dianne M Bryant; J Robert Giffin Journal: CMAJ Date: 2022-03-21 Impact factor: 16.859