HYPOTHESIS: Our aim was to test whether anatomically designed metallic radial head implants could better reproduce native radiocapitellar contact pressure and areas than nonanatomic implants. METHODS: The distal humerus and proximal radius from 6 cadaveric upper extremities were serially tested in supination with 100 N of compression force at 4 angles of flexion (0°, 30°, 60°, and 90°). By use of a thin flexible pressure transducer, contact pressures and areas were measured for the native radial head, an anatomic implant, a nonanatomic circular monopolar implant, and a bipolar nonanatomic implant. The data (mean contact pressure and mean contact area) were modeled using a 2-factor repeated-measures analysis of variance with P ≤ .05 considered to be significant. RESULTS: The mean contact areas for the prosthetic radial heads were significantly less than those seen with the intact radial heads at every angle tested (P < .01). The mean contact pressures increased significantly with all prosthetic radial head types as compared with the native head. The mean contact pressures increased by 29% with the anatomic prosthesis, 230% with the monopolar prosthesis, and 220% with the bipolar prosthesis. Peak pressures of more than 5 MPa were more commonly observed with both the monopolar and bipolar prostheses than with the anatomic or native radial heads. CONCLUSIONS: The geometry of radial head implants strongly influences their contact characteristics. In a direct radius-to-capitellum axial loading experiment, an anatomically designed radial head prosthesis had lower and more evenly distributed contact pressures than the nonanatomic implants that were tested.
HYPOTHESIS: Our aim was to test whether anatomically designed metallic radial head implants could better reproduce native radiocapitellar contact pressure and areas than nonanatomic implants. METHODS: The distal humerus and proximal radius from 6 cadaveric upper extremities were serially tested in supination with 100 N of compression force at 4 angles of flexion (0°, 30°, 60°, and 90°). By use of a thin flexible pressure transducer, contact pressures and areas were measured for the native radial head, an anatomic implant, a nonanatomic circular monopolar implant, and a bipolar nonanatomic implant. The data (mean contact pressure and mean contact area) were modeled using a 2-factor repeated-measures analysis of variance with P ≤ .05 considered to be significant. RESULTS: The mean contact areas for the prosthetic radial heads were significantly less than those seen with the intact radial heads at every angle tested (P < .01). The mean contact pressures increased significantly with all prosthetic radial head types as compared with the native head. The mean contact pressures increased by 29% with the anatomic prosthesis, 230% with the monopolar prosthesis, and 220% with the bipolar prosthesis. Peak pressures of more than 5 MPa were more commonly observed with both the monopolar and bipolar prostheses than with the anatomic or native radial heads. CONCLUSIONS: The geometry of radial head implants strongly influences their contact characteristics. In a direct radius-to-capitellum axial loading experiment, an anatomically designed radial head prosthesis had lower and more evenly distributed contact pressures than the nonanatomic implants that were tested.
Authors: Pierre Laumonerie; David Ancelin; Nicolas Reina; Meagan E Tibbo; Panagiotis Kerezoudis; Stephanie Delclaux; Nicolas Bonnevialle; Pierre Mansat Journal: Int Orthop Date: 2017-05-12 Impact factor: 3.075
Authors: Pierre Laumonerie; Meagan E Tibbo; Panagiotis Kerezoudis; Marc Olivier Gauci; Nicolas Reina; Nicolas Bonnevialle; Pierre Mansat Journal: Int Orthop Date: 2018-07-30 Impact factor: 3.075
Authors: Pierre Laumonerie; Meagan E Tibbo; Nicolas Reina; Thuy Trang Pham; Nicolas Bonnevialle; Pierre Mansat Journal: Int Orthop Date: 2018-08-10 Impact factor: 3.075
Authors: Pierre Laumonerie; Nicolas Reina; Claudia Gutierrez; Stephanie Delclaux; Meagan E Tibbo; Nicolas Bonnevialle; Pierre Mansat Journal: Int Orthop Date: 2017-09-21 Impact factor: 3.075
Authors: Pierre Laumonerie; Maroun Raad; Meagan E Tibbo; Panagiotis Kerezoudis; Nicolas Bonnevialle; Pierre Mansat Journal: Shoulder Elbow Date: 2019-05-19