Search results for " Notch"
showing 3 items of 53 documents
Physiological incongruity of the humero-ulnar joint: a functional principle of optimized stress distribution acting upon articulating surfaces?
1993
Investigations into the distribution of subchondral bone density in the human elbow have suggested that the geometry of the trochlear notch deviates from a perfect fit with the trochlea, and that the load is transmitted ventrally and dorsally rather than through the centre of the humero-ulnar joint. We therefore decided to make a quantitative assessment of the degree of incongruity between the two components in 15 human specimens (age distribution 60 to 93 years) with different types of joint surface. Polyether casts of the joint cavity were prepared under loads of 10, 40, 160 and 640 N. The thickness of the casts was then measured at 50 predetermined points, and an area distribution of the…
Morphomechanics of the humero-ulnar joint: I. Joint space width and contact areas as a function of load and flexion angle
1995
BACKGROUND Previous studies have shown that the trochlear notch is deeper than necessary for an exact fit with the humerus. However, humero-ulnar joint space width and contact areas have so far not been quantified for variations in the load and angle of flexion. METHODS Six fresh cadaveric specimens were investigated at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion and at loads of 25 and 500 N, simulating resisted elbow extension. The joint space width and contact were determined, using polyether casting material. RESULTS At 25 N all joints made contact in the ventral and dorsal aspects of the articular surfaces, whereas in the depth of the trochlear notch the joint space w…
Aston Medical Duocentric® Reversed Prosthesis: Proposition of New Glenoid Component Design to Prevent Scapular Neck Notching
2015
Medialization of the center of rotation in reverse shoulder arthroplasty (RSA) results in greater excursion of the proximal humerus especially in adduction leading to a mechanical conflict against the neck of the scapula, thus creating a specific complication: scapular notching, in up to 90 % of RSA. We describe our third generation of RSA in Dijon, the Duocentric prosthesis. This prosthesis provides a new proposition to prevent the notching problem with an inferior overhang integrated to the glenoid baseplate. Such an inferior extension prevents the malpositioning of the hemisphere and resurfaces the “critical zone” preventing notching.Phenomenon while a smaller neck-shaft angle on the hum…