Kinematics of the patellofemoral joint in total knee arthroplasty.
Sagittal plane patellofemoral kinematics was determined for 81 subjects while performing a weight-bearing deep knee bend under fluoroscopic surveillance. Fourteen normal knees, 12 anterior cruciate ligament (ACL)-deficient knees, and 55 total knee arthroplasties (TKAs) were assessed. Of TKAs, 39 had resurfacing with a dome-shaped patella, 8 had resurfacing with an anatomic mobile-bearing patella, and 8 were unresurfaced. TKA patellae experienced more superior patellofemoral contact and higher patellar tilt angles compared with the normal knees and ACL-deficient knees (P <.05). Patellofemoral separation at 5 degrees (+/-3 degrees ) extension was seen in 86% cruciate-retaining and 44% cruciate-stabilized TKAs and 8% ACL-deficient knees but not in the normal knees or mobile-bearing TKAs (P <.05). The patellar kinematic patterns for subjects having a TKA were more variable than subjects having either a normal knee or an ACL-deficient knee. Kinematic abnormalities of the prosthetic patellofemoral joint may reduce the effective extensor moment after TKA.
Stiehl
J B
JB
Midwest Orthopaedic Biomechanical Laboratory, Columbia Hospital, Milwaukee, Wisconsin, USA. jbstiehl@aol.com
Komistek
R D
RD
Dennis
D A
DA
Keblish
P A
PA
D016118:Anterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery; D001696:Biomechanical Phenomena; D019544:Equipment Failure Analysis; D005471:Fluoroscopy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007720:Knee Prosthesis; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology*; D016896:Treatment Outcome; D016474:Weight-Bearing / Q000502:physiology*