Abstract: A halo system orthopedic appliance includes an adjustable two poster arrangement in which the connections between the respective posts and the appliance are made with respective clamp mechanisms. Each poster is slidably received in a channel formed by each clamp. Each clamp is rotatably received on a single clamp screw which when tightened simultaneously fixes the slidably adjusted position of the post relative the clamp and the rotatably adjusted position of the clamp relative the appliance. Serrations on opposing surfaces between respectively paired clamps and adapter brackets carried on the halo ring, and respectively between two clamps and superstructure supported on a patient vest, enhances the clamping effect. During application of the appliance, the patient's skeletal process is first aligned in a desired orientation, and thereafter the four respective clamps located adjacent each end of the pair of posters are secured.

Abstract: An improved mechanical joint construction for pivotally interconnecting two members, particularly members of an orthopedic or orthotic body appliance, to limit the degree of pivotal movement between the members and adjustably control the position of limited pivotal movement of the two members; comprising first securement components for attachment to a first appliance member to be interconnected and presenting a generally flat planar surface with pivot pin extending outwardly from the surface and a protrusion on the surface spaced radially from the pivot pin; second securement components for rigid attachment to a second appliance member to be interconnected and comprising an inner peripherally serrated plate with central opening for receipt of the pivot pin to support the inner plate for rotation thereon, an arcuate slot in the inner plate spaced radially from the opening therein and receiving the protrusion for movement between ends of the slot to limit relative rotational movement of the inner plate on the p