title: Fluoroscopic analysis of kinematics after posterior-cruciate-retaining knee arthroplasty.
abstract: We used fluoroscopy to study the kinematics of the knee in 47 patients with total knee arthroplasty (TKA) and four control subjects with normal knees while performing a single-leg deep-knee bend. The videos were analysed using still photographs taken at 5 degrees increments of flexion. Femorotibial contact points, patellar ligament rotation, and patellar rotation were calculated from each image. Maximum weight-bearing flexion was determined for each knee. Compared with the control group, posterior-cruciate-retaining TKA did not reproduce normal knee kinematics in any case, but showed a starting point posterior to the tibial midline which translated anteriorly with flexion. The curves from successive knee bends could not be consistently reproduced. Under weight-bearing conditions, the maximum flexion for any PCR TKA was 98 degrees and several patients could not flex beyond 70 degrees.
authors.affiliation: Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee 53211, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Stiehl
authors.forename: R D
authors.initials: RD
authors.lastname: Komistek
authors.forename: D A
authors.initials: DA
authors.lastname: Dennis
authors.forename: R D
authors.initials: RD
authors.lastname: Paxson
authors.forename: W A
authors.initials: WA
authors.lastname: Hoff
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005471:Fluoroscopy; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007720:Knee Prosthesis; D008023:Ligaments, Articular / Q000503:physiopathology; D009068:Movement; D010147:Pain Measurement; D010329:Patella / Q000503:physiopathology; D016119:Posterior Cruciate Ligament; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology; D012399:Rotation; D013314:Stress, Mechanical; D016474:Weight-Bearing / Q000502:physiology