JOA - 2026-05-13 - Journal Article
The One-Year Postoperative Trajectories of Knee Joint Angle Recovery During Walking After Total Knee Arthroplasty in Women: A Cross-Sectional Study.
Fan CH, Hsu JH, Yu PA, Chen CL, Wen-Wei Hsu R, Hsu WH
Topics
Key Takeaway
Swing-phase knee flexion (55–75% of gait cycle) at 3–12 months post-TKA significantly predicted all KOOS subscales except sports/recreation, while operated-limb kinematics stabilized by 3 months postoperatively.
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Summary
This study examined how 3D gait kinematics evolve over the first postoperative year in women undergoing unilateral primary TKA and whether dynamic knee angles predict KOOS outcomes. Using 1D statistical parametric mapping, operated-limb knee joint angles stabilized by 3 months with minimal subsequent change, and swing-phase knee flexion (55–75% gait cycle) significantly predicted all KOOS subscales except sports/recreation. Inter-limb asymmetry was limited to greater terminal swing flexion in the non-operated limb at 3 months only.
Key Limitation
Cross-sectional design at each time point precludes within-subject longitudinal tracking of individual kinematic trajectories and their causal relationship with KOOS change.
Original Abstract
BACKGROUND
Total knee arthroplasty (TKA) effectively alleviates pain in end-stage knee osteoarthritis; however, postoperative functional recovery, particularly gait restoration, remains variable. Although knee range of motion (ROM) typically recovers early after surgery, its relationship with patient-reported outcomes such as the Knee injury and Osteoarthritis Outcome Score (KOOS) is inconsistent. Understanding how dynamic knee joint kinematics during walking evolve over time and relate to perceived function may provide sensitive recovery indicators.
METHODS
Women who underwent unilateral primary TKA were assessed at three, six, nine, and 12 months postoperatively. A three-dimensional gait analysis was used to quantify knee joint angles during walking, and KOOS subscales were collected concurrently. A one-dimensional statistical parametric mapping was applied to examine temporal changes in knee joint kinematics and their associations with KOOS outcomes.
RESULTS
Knee muscle strength, walking speed, and all KOOS subscales improved progressively over the first postoperative year. Knee joint kinematics of the operated limb stabilized by approximately three months, with minimal subsequent changes. There were no significant inter-limb differences observed, except for greater terminal swing knee flexion in the non-operated limb at three months. Notably, knee flexion angles of the operated limb during the swing phase (approximately 55.0 to 75.0% of the gait cycle) significantly predicted all KOOS subscales except sports/recreation.
CONCLUSION
These findings indicate that dynamic knee joint angles during walking, rather than static ROM measures, are closely associated with perceived knee function after TKA. Gait-based kinematic assessments may serve as valuable objective markers for monitoring recovery and guiding rehabilitation.