PURPOSE This study was performed to determine the incidence of acute bone-patellar tendon-bone autograft harvest complications after anterior cruciate ligament (ACL) reconstruction. METHODS Over a nearly 20-year period (September 1986 to April 2006), 1,725 consecutive patients underwent primary ACL reconstruction using bone-patellar tendon-bone autograft by 3 fellowship-trained sports medicin...

INTRODUCTION: Patellofemoral pain (PFP) is closely related to static patellar malalignment and patellar maltracking. The etiology of patellar maltracking is multifactorial; relating to femoral shape, passive soft-tissue restraints; and/or an imbalance of forces on the patella. A number of structures, both passive and active, contribute to the force balance on the patella. Previous studies have ...

INTRODUCTION The moment arm (ma) of a tendon is a crucial quantity for musculoskeletal dynamics as it defines how the linear force within a muscle is transformed into a torque. For the quadriceps this relationship is complicated by the fact that the patella serves as an intermediary (a dynamic fulcrum) between the quadriceps and tibia. Thus, the term effective quadriceps moment arm (EQma) was c...

The purpose of this study was to test the hypothesis that patella alta leads to a less favourable situation in terms of patellofemoral contact force, contact area and contact pressure than the normal patellar position, and thereby gives rise to anterior knee pain. A dynamic knee simulator system based on the Oxford rig and allowing six degrees of freedom was adapted in order to simulate and rec...

OBJECTIVE To compare the plateau-patella angle method to the methods already established for patellar height measurement in patients undergoing high tibial osteotomy. METHODS This is a retrospective study of 13 patients undergoing medial opening tibial osteotomy. The patellar height was measured in pre and post-operative radiographs by the methods from Insall-Salvati, Caton-Deschamps, Blackbu...

Complications involving the knee extensor mechanism and patellofemoral joint occur in 1% to 12% of patients following total knee arthroplasty and have major negative effects on patient outcomes and satisfaction. The surgeon must be aware of intraoperative, postoperative, and patient-related factors that can increase the rate of these problems. This review focuses on six of the most commonly enc...