Radiocapitellar joint contacts after bipolar radial head arthroplasty.
OBJECTIVE
The purpose of this study was to determine radiocapitellar contacts before and after radial head replacement, using the bipolar design of Judet.


METHODS
Joint contacts were measured by moulding the joint surfaces of 6 fresh-frozen cadaveric specimens, in various positions of elbow flexion and forearm rotation.


RESULTS
Expressed as function of the radial cup, contact areas averaged 44% in the normal elbow, decreasing with flexion and increasing with supination (P < .05). After prosthetic implantation, contact areas averaged 33% and remained quite similar, irrespective of elbow position. Subluxation of the prosthetic head over the lateral margin of the trochlea was seen systematically with supination.


CONCLUSIONS
Because of intraprosthetic mobility, contact areas were not dependant on elbow position. This adaptability, however, also led to abnormal positioning of the prosthetic radial head with supination, subluxing over the trochlea lateral margin.
Moungondo
Fabian
F
Department of Orthopaedics and Traumatology, Université libre de Bruxelles, Campus Hospitalo-Facultaire Erasme, Brussels, Belgium.
El Kazzi
Wissam
W
van Riet
Roger
R
Feipel
Véronique
V
Rooze
Marcel
M
Schuind
Frédéric
F
D019643:Arthroplasty, Replacement / Q000379:methods*; D001696:Biomechanical Phenomena; D002102:Cadaver; D004551:Elbow Joint / Q000601:surgery*; D006801:Humans; D006811:Humerus / Q000502:physiology / Q000601:surgery*; D007593:Joint Instability / Q000517:prevention & control; D007595:Joint Prosthesis; D011403:Pronation / Q000502:physiology; D011474:Prosthesis Design; D011884:Radius / Q000502:physiology / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology*; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013484:Supination / Q000502:physiology