Abstract: A fastener system for use in reattaching a skull flap in an opening formed in a patient's skull during brain surgery is simple, quick and easy to use, and cost effective. The system includes a fastener element and a substantially disc shaped lock element. The fastener element has a shank with a plurality of ratchet teeth, and a plurality ridges extending upwardly from the shank a distance greater than the height of the ratchet teeth, and substantially perpendicular to the ratchet teeth. The ridges engage at least one of the skull and skull flap and either bend or collapse, or cut locking grooves into the skull or skull flap, to provide a force holding the shank in engagement with the skull and skull flap. The lock element may have force concentrating projections extending outwardly toward the fastener head, and the head may have a plurality of resilient[ outrigger leaves.

Abstract: A fastener system for use in reattaching a skull flap in an opening formed in a patient's skull during brain surgery is simple, quick and easy to use, and cost effective. The system includes a fastener element and a substantially disc shaped lock element. The fastener element has a shank with a plurality of ratchet teeth, and a plurality ridges extending upwardly from the shank a distance greater than the height of the ratchet teeth, and substantially perpendicular to the ratchet teeth. The ridges engage at least one of the skull and skull flap and either bend or collapse, or cut locking grooves into the skull or skull flap, to provide a force holding the shank in engagement with the skull and skull flap. The lock element may have force concentrating projections extending outwardly toward the fastener head, and the head may have a plurality of resilient[ outrigger leaves.

Abstract: A fastener system for use in reattaching a skull flap in an opening formed in a patient's skull during brain surgery, is simple, quick, and easy to use, and is cost effective. The system includes a fastener element and a substantially disc shaped lock element. Both are made of bio-compatible radiolucent rigid plastic material. The fastener element has a substantially disc shaped head and a shank, the shank having substantially flat first and second substantially parallel surfaces having ratchet teeth on them. The shank typically has a thickness, with ratchet teeth, where it extends through a gap between the skull flap and the skull, of about 1-2 mm. The lock element has a through extending opening defined at least in part by locking teeth which cooperate with the ratchet teeth to allow the lock element to be brought tightly into contact with the skull and skull flap to hold the fastener and lock elements in place and to position the skull flap in the skull.

Abstract: Interlocking surface elements are created in such a way that there is almost 100% engagement between the surfaces, so that they positively lock together, and will not cam with respect to each other. Each element comprises a number of uniformly dimensioned semi-conically shaped surfaces emanating from a common center and disposed in an alternating inverted configuration. Each surface has first and second edges extending in a longitudinal direction. A flat surface of substantially constant dimension in a plane substantially perpendicular to the longitudinal direction connects the first and second edges of adjacent, alternately inverted, semi-conically shaped surfaces, so as to maximize the engagement area between the elements. The elements may be of vacuum formed plastic, molded plastic, or metal stampings. They may be circular (e.g. disc shaped) in plan, and the semi-conically shaped surfaces may all be hollow.

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.

Abstract: Cervical traction tongs having cooperating first and second curved arms made of MRI and biologically compatible and CT transparent material. Skull pins having main bodies of MRI and biologically compatible and CT transparent material, and pointed skull engaging tips of radiolucent material (e.g. single crystal alumina ceramic) extend through openings at one end of the arms, while at the other ends the arms are connected together in an adjustable manner, so as to adjust the spacing between the pin pointed tips. The arms have enlarged circular end terminations having radially extending serrations which cooperate together, and are held in a position to which they are moved by a through extending bolt and nut. The arms have sufficient elasticity to provide constant pressure urging the pointed pin tips against the human skull during use. A flexible strand for applying tension is passed through an arcuate elongated opening in the serrated end terminations of the arms.

Abstract: A bone penetrating pin for medical use includes, in one embodiment, a shank provided at one end with a bone penetrating element of titanium or single crystal alumina ceramic material, and a driving head at the other end. A removable cap is applied to the driving end, the cap including upper and lower cylindrical portions of substantially identical diameters interconnected by an intermediate portion of substantially smaller diameter. The upper portion is formed with oppositely extending arms for application of torque through the cap to the shank and bone penetrating element. The intermediate portion of the cap is designed to fail in shear upon the application of torque in excess of a predetermined maximum; that is, it provides a torque limiting function.

Abstract: A steerable medical probe device, such as a catheter, comprises a flexible, inner tubular body, a plurality of electrical conductors wrapped about the inner tubular body; and an insulating layer surrounding the conductors. Rigid non-conductive rings are adhesively secured at axially spaced locations along the distal end of the probe. A plurality of shape memory titanium-nickel wires extend between adjacent pairs of rings, and are electrically connected to a control device and power source. The control device may be operated to apply low current pulses selectively through one or more of the wires to effect contraction of the heated wires and thereby cause the distal end of the probe to bend in a desired direction.

Abstract: The skull of a patient is immobilized utilizing a generally ring-shaped member (crown) that can be used in place of a conventional halo or tongs, and is affixed to the patient's skull utilizing particularly advantageous skull pins. The crown has a first major portion which is in a first plane, and has a second portion extending at an angle out of the first plane. Preferably it has a generally horseshoe shape in plan view, with first and second ends spaced from each other, those ends being part of the second portion of the crown. Skull pins pass through threaded openings in the crown, including threaded openings in the second portion to attach the crown below a capital distal plane extending between the top of the ears and the top of the eyes of the patient's head. The rigid crown is preferably of a boron fiber or graphite fiber reinforced plastic. The skull pins, which do not artifact any more than bone does, comprise an exteriorly threaded cylinder of plastic (e.g.

Abstract: A portable cervical traction device is utilized to temporarily positively maintain cervical traction while a patient is transported from a stationary traction station to another station, such as an X-ray station. While the patient is in traction at a traction station, the backplate and shoulder supports of the portable device are attached to the patient. Upstanding from the backplate are a pair of telescoping components with compression springs, and at the top of those components is a cross bar. Slide rods extend outwardly from the cross bar to overhang the shoulder supports, and a slide bar slides along the slide rods. A cam cleat on the slide bar is moved into engagement with the traction cable at the traction site, and suitable counter-traction force is applied by compressing the springs associated with the telescoping components. Then the traction cable is released from its attachment at the traction station, and is wrapped around a deck cleat.

Abstract: A special halo assembly is used with a stereotaxic device including a frame having four radiolucent substantially planar walls with radiopague indicia formed on the walls, and is operatively fixed to the frame walls by brackets to positively position the halo assembly in a predetermined position with respect to the walls. The frame is fixed with respect to a radiotherapy machine or a CT scanner. The halo assembly includes a number of brackets each having a first portion fixed to the ring component of the assembly, and a second substantially planar portion extending radially outwardly from the ring component. A method of practicing radiotherapy on a patient having a brain lesion or the like is accomplished utilizing the device. The halo assembly is surgically affixed to the patient's head to be maintained in place until all radiotherapy sessions for the patient are completed.