Knee Frontal-Plane Biomechanics in Adults With or Without Bone Marrow Edema-Like Lesions After Anterior Cruciate Ligament Injury

Abstract

Lateral subchondral bone bruises (BBs) occur frequently with anterior cruciate ligament (ACL) injuries. These BBs are associated with pain during weight bearing, leading individuals to increase medial tibiofemoral loading to alleviate pain laterally. Increased medial tibiofemoral loading may precipitate the development or progression of posttraumatic osteoarthritis; however, no in vivo biomechanical data exist to confirm that lateral BBs increase medial tibiofemoral loading as measured by the external knee-adduction moment (KAM). To determine whether lateral BBs after ACL injury increase the external KAM during walking. Descriptive laboratory study. University research laboratory. Eleven volunteers with an ACL injury (age = 20.36 ± 4.03 years, height = 177.60 ± 8.59 cm, mass = 79.70 ± 16.33 kg), 12 with an ACL injury and a lateral BB (ACL + BB; age = 19.25 ± 5.58 years, height = 170.71 ± 9.40 cm, mass = 66.79 ± 11.91 kg), and 12 healthy controls (age = 19.67 ± 5.19 years, height = 173.29 ± 11.58 cm, mass = 67.07 ± 11.25 kg) participated. We recorded peak KAM during 3 walking trials (1.1 ± 0.6 m/s) in which participants walked over a force platform located in the field of view of a motion-capture system. Peak KAM was calculated during the first half of stance using standard inverse-dynamics analysis, averaged across trials, and examined via 1-way analysis of variance. Knee pain and function were determined from the International Knee Documentation Committee Subjective Knee Evaluation Form and compared among groups via the Kruskal-Wallis test. Peak KAM did not differ among groups (ACL injury = 0.14 ± 0.07 Nm·kg-1·m-1, ACL + BB = 0.21 ± 0.08 Nm·kg-1·m-1, control = 0.20 ± 0.08 Nm·kg-1·m-1; F2,35 = 3.243, P = .052). Knee-pain frequency and severity were greater in the ACL-injury (frequency = 2.55 ± 1.81, severity = 3.36 ± 1.75; both P < .001) and ACL + BB (frequency = 3.58 ± 2.81, severity = 4.08 ± 3.20; both P < .001) groups than in the control group (frequency = 0.00 ± 0.00, severity = 0.00 ± 0.00). Knee function was greater in the control group (100.00 ± 0.00) than in the ACL-injury (59.35 ± 17.31; P < .001) and ACL + BB (46.46 ± 25.85; P < .001) groups. The ACL + BB groups did not walk with a greater external KAM than the ACL-injury or control groups. Thus, lateral tibiofemoral BB did not influence knee frontal-plane loading after ACL injury.