Kinematic comparison of posterior cruciate sacrifice versus substitution in a mobile bearing total knee arthroplasty.
Interest in mobile bearing total knee arthroplasty (TKA) has increased significantly. The objective of this in vivo study was to analyze 2 different mobile bearing TKAs during gait and during a knee bend from 0 degrees to 90 degrees flexion. Femorotibial contact positions for 10 subjects, implanted by a single surgeon, were analyzed using videofluoroscopy. Five subjects were implanted with a posterior-stabilized mobile bearing TKA (PS), and 5 subjects were implanted with a posterior cruciate-sacrificing mobile bearing TKA (PCS). Each subject, while under fluoroscopic surveillance, performed 2 weight-bearing activities: i) normal gait and ii) deep-knee bend. This study showed that the kinematic patterns for subjects having either a PS or PCS mobile bearing TKA were similar during gait but different during a deep-knee bend. Subjects having a PS TKA experienced more posterior femoral rollback of the lateral condyle during the deep-knee bend. Findings of kinematic similarities in gait and differences in a deep-knee bend between these 2 mobile bearing designs are similar to previously published findings of fixed bearing posterior cruciate-retaining and PS TKA.
Haas
Brian D
BD
Rocky Mountain Musculoskeletal Research Laboratory, Denver, Colorado 80222, USA. haasb@aol.com.
Komistek
Richard D
RD
Stiehl
James B
JB
Anderson
Dylan T
DT
Northcut
Eric J
EJ
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D005471:Fluoroscopy; D006801:Humans; D007720:Knee Prosthesis; D008875:Middle Aged; D011474:Prosthesis Design; D014741:Video Recording