CONSEQUENCES OF A MID-THIRD BPTB-AUTOGRAFT EXCISION ON PATELLOFEMORAL BIOMECHANICS AND KNEE KINEMATICS

Introduction: This biomechanical study evaluates the consequences of a mid-third BPTB-autograft excision on patellofemoral biomechanics and knee kinematics. Of particular interest was the potential role of a BPTB-autograft excision on postoperative anterior knee pain in ACL replacement surgery. Methods: Isokinetic knee extension from 120 of flexion to full extension was simulated on 9 human knee cadaver specimens (5 male, 4 female, average age at death 43 years). Joint kinematics was evaluated by ultrasound sensors (CMS 100TM, Zebris, Isny, Germany), and retro-patellar contact pressure was measured using a thin-film resistive ink pressure system (K-ScanTM 4000, Tekscan, Boston). All data were taken before and after excision of a mid-third BPTB-autograft. Results: Following excision of a mid-third patella tendon autograft we found a significant (p Conclusions: We conclude that an excision of a mid-third patella tendon autograft results in a lengthening of the tendon with a proximalization of the patella. As the patellofemoral pressure decreases and the patella remains centralized, postoperative anterior knee pain following ACL-replacement using a BPTB autograft can not be explained by the results of our study.