Abstract: A shaped halo vest includes front and back vest components for overlying the front and back of the patient's upper torso. Each component is shaped three-dimensionally to load selected areas of the body, i.e., selected muscle groups, and avoid loading other selected areas of the body, i.e., bony prominences. The shaping includes three-dimensional compound curves for bowing the molded plastic vest components inwardly to transfer loads or outwardly to avoid transfer of loads. The marginal edges of the vest components are flared outwardly to avoid pinching or bruising the underlying tissue upon relative movement of the patient and vest. The three-dimensional compound curves and the flared edges contribute to the structural rigidity of the vest. The front and back components are secured one to the other by adjustable straps along the opposite sides of the lower portions of the vest and adjustable length shoulder straps. Vent holes are provided in the back vest component.

Abstract: A skull pin provides greater resistance to shear forces so that it may be more readily made of titanium, ceramic or gem stone, yet still prevents undue penetration, and can be tightened if wear or erosion of the skull results from cyclic loading. The pin is used with a halo or cervical traction ring, and has a main, externally threaded, circular cylindrical body, and a skull engaging portion. The skull engaging portions is formed by first and second concentric, in-line cylinders terminating in conical sections, the first conical section terminating in the second cylinder (which resists shear forces much better than conventional skull pins), and the second conical section terminating in a pointed tip. The first cylinder has a diameter of about 0.18 inches, the first conical section has a length of about 0.09 inches and approximately a 60.degree. taper angle, the second cylinder has a length of about 0.03 inches and a diameter of about 0.07 inches, and the second conical section has approximately a 60.degree.