title: Kinematics of semi-constrained total elbow arthroplasty.
abstract: We used 11 cadaver elbows and a three-dimensional electromagnetic tracking device to record elbow movements before and after implantation of a 'loose-hinged' elbow prosthesis (modified Coonrad). During simulated active motion there was a maximum of 2.7 degrees (+/- 1.5 degrees) varus/valgus laxity in the cadaver joints. This increased slightly after total elbow arthroplasty to 3.8 degrees (+/- 1.4 degrees). These values are lower than those recorded for the cadaver joints and for the prostheses at the limits of their varus/valgus displacements, indicating that both behave as 'semi-constrained' joints under physiological conditions. They suggest that the muscles absorb some of the forces and moments that in a constrained prosthesis would be transferred to the prosthesis-bone interface.
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: S W
authors.initials: SW
authors.lastname: O'Driscoll
authors.forename: K N
authors.initials: KN
authors.lastname: An
authors.forename: S
authors.initials: S
authors.lastname: Korinek
authors.forename: B F
authors.initials: BF
authors.lastname: Morrey
mesh_terms: D001696:Biomechanical Phenomena; D002102:Cadaver; D004551:Elbow Joint / Q000502:physiology*; D055590:Electromagnetic Phenomena / Q000295:instrumentation; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D007595:Joint Prosthesis; D009068:Movement / Q000502:physiology; D012399:Rotation