Anterior cruciate ligament reconstruction alters the patellar alignment

Although there are many articles dealing with anterior cruciate ligament (A CL) reconstruction, there are none dealing with the possibility of changes of the patellofemoral alignment after these procedures. Forty-six patients were evaluated preoperatively and 1 year postoperatively, after undergoing intra-articular ACL reconstruction for changes of the patellofemoral alignm ent. Patella-tilt and congruence angles were measured on tangential view ra diographs that were taken in the supine position. Analysis of covariance wa s performed and revealed a significant change of the congruence angle I yea r postoperatively. The patella-tilt did not change. One year postoperativel y, the patella shifted on average 5 degrees medially after ACL grafting. It can be deduced that anterior knee pain after ACL reconstruction could be c aused by distinct changes in the patellofemoral alignment.