Changes Following ACL Injury and Reconstruction

Subjects with anterior cruciate ligament reconstructed knees (ACL-R) are reported to have higher risk for knee osteoarthritis. Understanding changes following ACL injury and reconstruction may lead to prevention and early intervention of knee osteoarthritis. Twenty-nine subjects with unilateral ACL-R knee and 19 healthy subjects with bilateral ACL-intact knees (ACL-I) were recruited for the study. Using our custom MatLab program, the thigh dimensions (i.e., volume, thigh cross section centroids) were determined from 3D body scans. The 3-D knee joint motion and thigh skin stretch during level walking were determined using motion analysis and compared between groups during daily activities. For 14 left ACL-R knees (lACL-R), there were no significant bilateral differences in thigh volume, whereas, for 15 right ACL-R knees (rACL-R), their thigh volume was significantly smaller than their noninvolved left thigh. Significant bilateral differences in knee joint varus-valgus rotation were also found among rACL-R group. The altered secondary knee joint movement along with weaker and smaller knee muscles during daily activities may be responsible for posttraumatic osteoarthritis commonly seen in clinic.