Patellofemoral Joint Contact Area During Gait is Significantly Reduced in ACL-reconstructed and Uninjured Contralateral Knees Compared to Healthy Controls.

Computed tomography, magnetic resonance imaging, and biplane X-ray fluoroscopy were combined to determine patellofemoral contact area in the anterior-cruciate-ligament reconstruction and uninjured contralateral knees of 15 individuals (26.3 ± 3.9 years) during level walking and downhill walking, and the results were compared to data for 10 healthy controls (29.8 ± 6.1 years).

On average, total, lateral, and medial patellofemoral contact areas in anterior-cruciate-ligament reconstruction and contralateral knees were approximately one-half of those in healthy knees (p < 0.001).