Progressive Changes in Walking Kinematics and Kinetics After Anterior Cruciate Ligament Injury and Reconstruction: A Review and Meta-Analysis

Abstract

Context: Anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) result in persistent alterations in lower extremity movement patterns. The progression of lower extremity biomechanics from the time of injury has not been described.

Objective: To compare the 3-dimensional (3D) lower extremity kinematics and kinetics of walking among individuals with ACL deficiency (ACLD), individuals with ACLR, and healthy control participants from 3 to 64 months after ACLR.

Data sources: We searched PubMed and Web of Science from 1970 through 2013.

Study selection and data extraction: We selected only articles that provided peak kinematic and kinetic values during walking in individuals with ACLD or ACLR and comparison with a healthy control group or the contralateral uninjured limb.

Data synthesis: A total of 27 of 511 identified studies were included. Weighted means, pooled standard deviations, and 95% confidence intervals were calculated for the healthy control, ACLD, and ACLR groups at each reported time since surgery. The magnitude of between-groups (ACLR versus ACLD, control, or contralateral limb) differences at each time point was evaluated using Cohen d effect sizes and associated 95% confidence intervals. Peak knee-flexion angle (Cohen d = -0.41) and external knee-extensor moment (Cohen d = -0.68) were smaller in the ACLD than in the healthy control group. Peak knee-flexion angle (Cohen d range = -0.78 to -1.23) and external knee-extensor moment (Cohen d range = -1.39 to -2.16) were smaller in the ACLR group from 10 to 40 months after ACLR. Reductions in external knee-adduction moment (Cohen d range = -0.50 to -1.23) were present from 9 to 42 months after ACLR.

Conclusions: Reductions in peak knee-flexion angle, external knee-flexion moment, and external knee-adduction moment were present in the ACLD and ACLR groups. This movement profile during the loading phase of gait has been linked to knee-cartilage degeneration and may contribute to the development of osteoarthritis after ACLR.

Keywords: anterior cruciate ligament deficiency; gait biomechanics; knee osteoarthritis; movement dysfunction.

Figure 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart depicting the search strategy and process of study retention, which was completed July 1, 2015.

Figure 2.

A, Peak external knee-flexion moment and, B, knee-extension moment point estimates with 95% confidence intervals for the healthy control group, anterior cruciate ligament reconstruction (ACLR) contralateral limb group, anterior cruciate ligament deficiency (ACLD) group, and each reported time point after ACLR during stance phase of walking gait. All moments are normalized to percentage of body weight and height. The 95% confidence interval for the healthy control group is represented using a shaded bar for comparison to all groups and time points.

Figure 3.

A, Peak knee-flexion angle point estimates with 95% confidence intervals for the healthy control group, anterior cruciate ligament reconstruction (ACLR) contralateral limb group, anterior cruciate ligament deficient (ACLD) contralateral limb group, ACLD group, and each reported time point after ACLR during the stance phase of walking gait. B, Peak hip-flexion angle point estimates with 95% confidence intervals for the healthy control group, ACLR contralateral limb group, ACLD group, and each reported time point after ACLR during the stance phase of walking gait. The 95% confidence interval for the healthy control group is represented using a shaded bar for comparison to all groups and time points.

Figure 4.

A, Peak knee-adduction angle point estimates with 95% confidence intervals for the healthy control group, anterior cruciate ligament reconstruction (ACLR) contralateral limb group, anterior cruciate ligament deficient (ACLD) contralateral limb group, ACLD group, and each reported time point after ACLR during the stance phase of walking gait. B, Peak external knee-adduction moment point estimates with 95% confidence intervals for the healthy control group, ACLR contralateral limb group, ACLD group, and each reported time point after ACLR during the stance phase of walking gait. All moments are normalized to percentage of body weight and height. The 95% confidence interval for the healthy control group is represented using a shaded bar for comparison to all groups and time points.

Figure 5.

Peak knee-internal rotation angle point estimates with 95% confidence intervals for the healthy control group, anterior cruciate ligament reconstruction (ACLR) contralateral limb group, anterior cruciate ligament deficient (ACLD) group, and each reported time point after ACLR during the stance phase of walking gait. The 95% confidence interval for the healthy control group is represented using a shaded bar for comparison to all groups and time points.