PATELLO FEMORAL CHANGES 24.5 YEARS AFTER BPTB ACL RECONSTRUCTION

Abstract

Introduction: The degenerative changes in the patello-femoral joint after an autologous bone-tendon-bone anterior cruciate ligament reconstruction were studied using plain radiology more than 24 years after the surgical procedure.

Material and Methods: One hundred patients out of a total of 148 patients could be reviewed at 24.5 years follow-up. Radiological analysis included joint space width narrowing classification of the medial and lateral facet according to IKDC and patellar height according to Caton-Deschamps index (CDI).

Results: Fifty four percent of patients had medial femorotibial moderate or severe degenerative changes.

Medial patello-femoral degenerative changes were found more frequently and these lesions were more pronounced: 20% had narrowing < 50% (IKDC C) and 4% had narrowing > 50% (IKDC D). Onset of medial patellofemoral osteoarthritis was correlated with medial femorotibial osteoarthritis (p< 0,001).

Patellar height was statistically different between the operated and controlateral knee (CDI = 0.92 and 0.96, p< 0.001). Patella baja (CDI< 0.8, frequency 9.9%) was correlated with medial femoro-patellar osteoarthritis (< 0.001) and postoperative cast immobilisation (p=0.047).

Discussion: Patello-femoral degenerative changes observed 24.5 years after ACL reconstruction are part of the global degenerative changes of the knee joint. Harvesting of the patellar tendon for anterior cruciate ligament reconstruction results in a only 0.04 point decrease of the Caton-Deschamps index 24.5 years after surgery.