Abstract: An ergonomic hand grip for a hand operated tool has a pair of spaced apart curvilinear side beams having first ends and second ends, the first ends being coupled to each other; a forearm brace coupling the second ends of the side beams to each other, the forearm brace extending in a direction from the second ends toward the first ends, and only on one side of the side beams; and a gripping member mounted between the side beams, the gripping member being neither parallel to nor perpendicular to said side beams. The gripping member acts as a flat spring and the side beams act as a pair of torsion springs.

Abstract: A hip prosthesis (20) having a shell (22), liner (24), and retainer ring (26) is utilized for hip arthroplasty. The liner (24) fits inside the shell (22), which is attached to a patient's pelvis, and the retainer ring (26) engages a terminal liner margin (54) to inhibit expansion of and decrease the size of a restricted liner opening (72) defined by the liner margin (54). By inhibiting expansion of the liner opening (72), the ball (92) of a patient's femur (90) is securely held in the liner (24). In one embodiment, the liner (98) is inhibited from rotation relative to the shell (96) by a plurality of protrusions (106) which mate with recesses (102) in the shell (96). In that embodiment, the liner (98) is provided with catch lips (108) to hold the liner (98) in the shell (96) and a positioning flange (110) which operates to form a relief gap (120) between the shell (96) and the liner (98).

Abstract: Improved polymeric orthopaedic compositions are disclosed wherein sized, functional fibers are incorporated into a physiologically acceptable matrix. The compositions of the invention can be fabricated in the form of particulate powders adapted for reinforcment of bone cements, continuous media for such cements, and orthopaedic implant coatings. A complete implant attachment system is also provided, made up of a fiber reinforced implant coating, and a compatible fiber-reinforced cement. In preferred forms, the fibers have a layer of sizing thereover which is chemically joined both to the surface of the fibers and to the surrounding matrix, and the fibers are present at a level of at least about 6 volume percent. If desired, sized radiopaque particles may be incorporated into the compositions of the invention. The fibers are advantageously polymeric in nature and of intermediate stiffness, whereas the matrix fraction is preferably polymethylmethacrylate.

Abstract: Improved polymeric orthopaedic compositions are disclosed wherein sized, functional fibers are incorporated into a physiologically acceptable matrix. The compositions of the invention can be fabricated in the form of particulate powders adapted for reinforcment of bone cements, continuous media for such cements, and orthopaedic implant coatings. A complete implant attachment system is also provided, made up of a fiber reinforced implant coating, and a compatible fiber-reinforced cement. In preferred forms, the fibers have a layer of sizing thereover which is chemically joined both to the surface of the fibers and to the surrounding matrix, and the fibers are present at a level of at least about 6 volume percent. If desired, sized radiopaque particles may be incorporated into the compositions of the invention. The fibers are advantageously polymeric in nature and of intermediate stiffness, whereas the matrix fraction is preferably polymethylmethacrylate.

Abstract: An orthopaedic device designed to replace an articulating surface in a joint is provided. The device has a relatively low stiffness factor and is capable of applying normal physiological load onto the underlying bone. A low stiffness factor is achieved by a relatively thin device made from materials that have a low bulk modulus of elasticity. The device is provided with curvature to minimize bending stress in the device so that the device has sufficient mechanical strength to prevent stress induced failure. A tibial component made in accordance with this invention is also provided.

Abstract: An orthopaedic surgical implant apparatus includes an elongated intramedullary rod assembly 10 for use in uniting a pair of bone segments wherein each of the bone segments includes a medullary cavity. The elongated intramedullary rod assembly 10 defines a central longitudinal axis when assembled and includes first and second points of attachment 26, 48, the rod assembly 10 being adapted to be positioned within the medullary cavities of the bone segments and secured to the first bond segment at the first point of attachment 26 and to the second bone segment at the second point of attachment 48. Structure 18, 52 is provided for shortening the predetermined distance between the first and second points of attachment 26, 48 of the rod assembly in the direction of the longitudinal axis after the rod assembly has been connected to the first and second bone segments so that the first and second bone segments are brought into contact with and press against one another.

Abstract: The use of re-entrant foam material as implants is disclosed. The re-entrant foam material may comprise the entire implant or other material may be used as a substrate with either a portion of the implant made of re-entrant material or a coating of re-entrant material may be applied or bonded to the substrate.

Abstract: A three-plane goniometer or angle measuring apparatus includes three small potentiometers which are closely spaced together to measure rotation of the knee about three different axes. The unit is primarily mounted on a cuff on the outside of the thigh. The mounting assembly for the three plane goniometer includes a curved yoke where the ends of the yoke curve from the front to the rear, with the goniometer unit being held between the ends of the rearwardly extending arms of the yoke, so that accurate measurement may be maintained in all three planes even while the knee is bent to its extreme flexed position. Extending downwardly from the goniometer is a square rod which slidably engages a square hole in a nylon ball mounted in a two-axis gimbal, which is secured to a cuff strapped to the calf of the leg.