Du Hyun Ro1, Hyuk-Soo Han1, Seong Hwan Kim2, Yoon-Ho Kwak1, Jae-Young Park1, Myung Chul Lee3. 1. Seoul National University Hospital, Chongnogu, Seoul, Republic of Korea. 2. Hanmaeum Changwon Hospital, Republic of Korea. 3. Seoul National University Hospital, Chongnogu, Seoul, Republic of Korea. Electronic address: leemc@snu.ac.kr.
Abstract
BACKGROUND: The goals of this study were (1) to document the gait pattern of patients with unilateral knee osteoarthritis (OA), (2) to determine the knee adduction moment (KAM) changes in the non-operated knee, and (3) to identify the predictors of change in KAM in the non-operated knee. METHODS: The study recruited 23 patients with advanced unilateral knee OA. The preoperative Kellgren-Lawrence (KL) grade of the non-operated knee was one or two; non-operated knee pain, rated using a numeric rating scale (NRS), was less than three out of 10 points. We used a commercial gait analysis system to evaluate kinetics and kinematics. Radiological and gait measurements at the two-year follow-up were compared with baseline data. RESULTS: The preoperative asymmetrical gait cycle characterized by elongation of the stance phase of the non-operated knee became symmetrical after TKA. The average KAM of the non-operated knee increased (P=0.010) and it was best predicted by the baseline mechanical axis of the non-operated knee. If the baseline mechanical axis was varus four degrees or above (varus group), the average KAM increased by 0.64 (% body weight×height, P=0.015), while for varus less than four degrees (non-varus group), KAM was unchanged. The KL grade was increased in the varus group (P=0.020) but it was unchanged in the non-varus group. Average pain NRS score was also higher (P=0.044) in the varus group. CONCLUSIONS: Close follow-up is necessary for patients with a baseline varus deformity of the non-operated knee because of the higher possibility of developing pain, subsequent arthritis and increased joint loading of the non-operated knee. LEVEL OF EVIDENCE: III, retrospective cohort study.
BACKGROUND: The goals of this study were (1) to document the gait pattern of patients with unilateral knee osteoarthritis (OA), (2) to determine the knee adduction moment (KAM) changes in the non-operated knee, and (3) to identify the predictors of change in KAM in the non-operated knee. METHODS: The study recruited 23 patients with advanced unilateral knee OA. The preoperative Kellgren-Lawrence (KL) grade of the non-operated knee was one or two; non-operated knee pain, rated using a numeric rating scale (NRS), was less than three out of 10 points. We used a commercial gait analysis system to evaluate kinetics and kinematics. Radiological and gait measurements at the two-year follow-up were compared with baseline data. RESULTS: The preoperative asymmetrical gait cycle characterized by elongation of the stance phase of the non-operated knee became symmetrical after TKA. The average KAM of the non-operated knee increased (P=0.010) and it was best predicted by the baseline mechanical axis of the non-operated knee. If the baseline mechanical axis was varus four degrees or above (varus group), the average KAM increased by 0.64 (% body weight×height, P=0.015), while for varus less than four degrees (non-varus group), KAM was unchanged. The KL grade was increased in the varus group (P=0.020) but it was unchanged in the non-varus group. Average pain NRS score was also higher (P=0.044) in the varus group. CONCLUSIONS: Close follow-up is necessary for patients with a baseline varus deformity of the non-operated knee because of the higher possibility of developing pain, subsequent arthritis and increased joint loading of the non-operated knee. LEVEL OF EVIDENCE: III, retrospective cohort study.
Authors: Stefan van Drongelen; Hanna Kaldowski; Timur Tarhan; Ayman Assi; Andrea Meurer; Felix Stief Journal: BMC Musculoskelet Disord Date: 2019-11-10 Impact factor: 2.362