Load mechanics of the midcarpal joint.
The midcarpal joint was studied in upper extremities of fresh cadavers with the use of a static positioning frame, pressure-sensitive film, and a microcomputer to analyze the contact prints. The contact area on the proximal side of the midcarpal joint was found to consist generally of four areas; the scaphoid-trapezium-trapezoid, the scaphoid-capitate, the lunate-capitate, and the triquetrum-hamate. The contact areas accounted for less than 40% of the available joint surface, even under loads of 118 pounds. The distribution of load through the midcarpal joint was scaphoid-trapezium-trapezoid 23%, scaphoid-capitate 28%, lunate-capitate 29%, and triquetrum-hamate 20%. The midcarpal joint, like the radiocarpal joint, appears to transmit load through distinct areas and through a relatively small portion of the available joint surface.
Viegas
S F
SF
Division of Orthopaedic Surgery, University of Texas Medical Branch, Galveston 77551.
Patterson
R M
RM
Todd
P D
PD
McCarty
P
P
D001696:Biomechanical Phenomena; D002348:Carpal Bones / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D013314:Stress, Mechanical; D014955:Wrist Joint / Q000502:physiology*