Abstract: A system for performing osteotomies includes a bone plate and a retractor assembly. The bone plate generally includes a first mounting portion for attachment to a first bone portion, a second mounting portion for attachment to a ssecond bone portion, and an intermediate portion connecting the first mounting portion and the second mounting portion. The retractor assembly includes first and second handle members coupled for relative movement about a first pivot axis and first and second jaw members coupled to the first and second handle members, respectively.

Abstract: An apparatus for a spinal fixation generally includes a hook member and a linkage. The hook member includes an upper portion and a lower portion. The lower portion has a generally arcuate shape and defines an aperture passing therethrough. The lower portion has a curved shape for engaging the lamina. The linkage includes a generally flat plate and defines an arcuate service for matingly receiving the upper portion of the hook member so as to permit relative rotation therebetween. The apparatus further includes a coupling arrangement including a shaft passing through the recess of the linkage and an aperture of the hook member. The shaft includes an upper end and a lower end. A locking member is carried by a lower end and disposed within an aperture of the hook member. A nut is provided in threaded engagement with the upper end of the shaft.

Abstract: An apparatus for spinal fixation has a longitudinally extending core which provides structural integrity and allows for bone growth along the center column of the spine. The apparatus for spinal fixation further includes upper and lower platform members radially extending from upper and lower ends, respectively, of the core. The platform members each include a plurality of radially extending arms which define substantially triangular openings therebetween. The openings permit bone ingrowth therethrough to the space between the upper and lower platform members which is interrupted only by the core.

Abstract: A spinal fusion stimulator comprising an interbody fusion cage or other interbody fixation device adapted to be implanted in the intervertebral disc space of a patient's spine, the interbody fusion cage in the preferred embodiment having a hollow body with internal and external conductive surfaces. The stimulator includes a constant current generator connected to the interbody fusion cage and set to provide a DC current effective to produce a surface current density of at least 1 &mgr;A/cm2 in the interbody fusion cage when implanted.

Abstract: An external fixation system for securing a first bone portion in a fixed relationship with respect to a second bone portion. The fixation system includes at least one cylindrical support rod and a plurality of universal clamp assemblies for engagement with at least one support rod. The fixation system additionally includes various other distinct components for interconnecting the support rod with bone pins engaged with the bone. Some of the other components are formed to include serrations for engaging corresponding serrations provided on the universal clamp assemblies. Some of the components include a cylindrical portion, whereas other of the components include a rod receiving portion adapted to receive the at least one support rod or one of the cylindrical portions. These interchangeable and distinct components allow for a greater degree of surgeon flexibility in producing a desired construction to secure bone portions with bone pins.

Abstract: An external fixator for securing a bone through a first bone screw connected to a first portion of the bone and a second bone screw connected to a second portion of the bone. The external fixator includes a first bone screw clamping assembly for receiving the first bone screw and a second bone screw clamping assembly for receiving the second bone screw. The external fixator additionally includes an angular correction module connecting the first and second bone screw clamping assemblies. The angular correction module includes a first element and a second element coupled to allow articulation of the first bone screw clamping assembly relative to the second bone screw clamping assembly about a center of rotation spaced from the module.

Abstract: An apparatus for external fixation of the pelvis includes first and second pluralities of bone screws adapted to be connected to first and second portions of the pelvis, respectively. The apparatus additionally includes a first bone screw clamp for receiving the first plurality of bone screws and a second bone screw clamp for receiving the second plurality of bone screws. Further, the apparatus includes a frame for securing the first bone screw clamp to the second bone screw clamp. The frame includes a transversely extending member which is articulable between a first position and a second position such that the transversely extending member is displaced in an inferior/superior direction when the frame is articulated from the first position to the second position.

Abstract: An apparatus for adjustably securing the humerous, which is on a proximal side of elbow joint, relative to the ulna on the distal side of the elbow joint. The apparatus includes a central body having inner and outer ring members interconnected for relative rotation about a common mechanical axis adapted to align with the anatomical axis of the elbow joint. The central body defines a radiographic window for permitting lateral radiographic examination of the anatomical pivot axis of the elbow joint. The apparatus preferably includes a distraction mechanism for distracting the humerus perpendicular to the proximal end of the ulna.

Abstract: An implantable bone growth stimulator comprising an electrical signal generator having an anode connected thereto along with a prefabricated flexible wire mesh cathode that is extendable to at least twice its preformed initial length. The cathode in a preferred embodiment includes a single chain of conductive wire links formed as alternating loops and twists of two strands of monofilament titanium wire.

Abstract: An external fixator for securing a first bone portion in a fixed relationship with respect to a second bone portion. The fixator includes a bone screw clamping assembly for receiving a first bone screw which is connected to the first bone portion and which includes a spherical portion. The fixator further includes a bone screw clamping assembly which is operable to receive a second bone screw which is connected to the second bone portion and which has a spherical portion. The fixator also includes a connection member having a main body portion and an internal module adjustably mounted within the main body portion. The internal module receives a spherical end of one of the bone screw clamps and selectively permits universal movement thereof. The internal module may be linearly adjusted within the connection member independently in first and second directions which are substantially perpendicular to one another.

Abstract: An external fixator for adjustably securing first and second portions of a bone includes a ring assembly and a bone screw clamp assembly interconnected by a central body. The ring assembly secures one or more tension wires adapted to pass through the first portion of the bone. The bone screw clamp assembly secures one or more bone screws adapted to engage a second portion of the bone. The ring assembly includes a generally circular frame having a peripheral groove for securing a tension wire carriage anywhere therealong. The tension wire carriages are adjustable so that the tension wire may be positioned above or below the ring. One or more connector rods are used to rigidify the external fixator by interconnecting the ring assembly and the bone screw clamp assembly.

Abstract: An external fixator for securing a first bone portion in a position relative to a second bone portion. The fixator includes a first clamping assembly for receiving a first bone screw connected to the first bone portion and a second clamping assembly for receiving a second bone screw connected to the second bone portion. The first and second clamping assemblies are interconnected by a main body which includes a plurality of serrated joints. Each serrated joint preferably includes first and second overlapping flanges which carry cooperating serrated surfaces adapted to selectively interlock. Each joint includes a fastener defining a pivot axis, the fasteners being operative to mechanically separate the cooperating serrated surfaces upon rotation in a first direction.

Abstract: An external fixator for adjustably securing a first bone portion in a position relative to a second bone portion. The fixator includes a first clamping assembly for receiving a first bone screw connected to the first bone portion and a second clamping assembly for receiving a second bone screw connected to the second bone portion. The first and second clamping assemblies are interconnected by a connection member. The external fixator also includes a drive unit for controlling angular adjustment of the second clamping assembly relative to the first clamping assembly.

Abstract: An external fixator for securing a first bone portion in a fixed relationship with respect to a second bone portion. The fixator includes a bone screw clamp for receiving a first bone screw which is connected to the first bone portion and which includes a spherical portion. The fixator further includes a bone screw clamp which is operable to receive a second bone screw which is connected to the second bone portion and which has a spherical portion. The fixator also includes a connection member having a radiographic window to permit radiographic examination of the bone fracture, as well as a cantilever member operable to secure the spherical portions of the first and second bone screw clamps to the connection member.

Abstract: A fixator for securing a first bone portion in a position relative to a second bone portion. The fixator includes a first bone screw clamp that serves as a template for drilling a hole in a first bone portion and that secures the first bone screw to the fixator. The fixator also includes a second bone screw clamp that serves as a template for drilling a hole in the second bone portion and that secures the second bone screw to the fixator once the second bone screw is secured to the second bone portion. The fixator also includes a main body that is operable to secure the first bone screw clamp to the second bone screw clamp.

Abstract: Invented are methods and an apparatus for faradic stimulation of osteogenesis by control of electrochemical reactions through maintenance of a stimulus between a cathode and anode yielding only beneficial electrochemical reactions at the cathode, the site of desired osteogenesis, while preventing any detrimental reaction at the same. Said methods and apparatus maintain a stimulus yielding the maximum acceptable level of oxygen consumption and pH elevation at the cathode, either with or without the formation of hydrogen peroxide as only an intermediate chemical species, while preventing the initiation of hydrogen gas evolution at the same such that the stimulus results in depression of oxygen tension plus elevation of pH, environmental effects that favor osteogenesis, and prevents a reaction resulting in elevation of pH plus hydrogen gas evolution, the latter effect being detrimental to the same.

Abstract: A noninvasive apparatus for treating living tissue and cells by means of a pulsed electromagnetic field, and particularly suitable for bone growth stimulation. A treatment coil is noninvasively mounted in proximity to an afflicted body part to be treated, and an electronic generator coupled to said treatment coil generates pulses having a positive pulse portion 200 to 250 microseconds in duration and a negative pulse portion having a duration less than approximately 50 microseconds, the pulses further characterized by a smooth transition at least from the leading edge to a relatively flat top segment. High-frequency content is substantially reduced, particularly at frequencies above 200 kHz.

Abstract: A method including applying varying signals to a first electrode at the tissue site and a second electrode remote from the tissue site and monitoring the results to determine a distinctive transition in the current-voltage characteristics of the electrode pair. A signal is then selected and applied to the electrodes to operate beyond the transition. Periodically, a varying signal is applied to the electrodes and the monitoring process reperformed to determine a new transition and an appropriate signal is selected to operate beyond the transition.

Abstract: Venous blood flow in a non-ambulating human leg is involuntarily promoted in a repeating cycle of successively actuated venous pumps, in imitation of the pump-actuating sequence which characterizes normal walking. Specifically, in the preferred embodiment, the proximal calf pump and the distal calf pump are operated, in that sequential order, following a given operation of the foot pump and prior to the next successive operation of the foot pump.

Abstract: A method including applying varying signals to a first electrode at the tissue site and a second electrode remote from the tissue site and monitoring the results to determine a distinctive transition in the current-voltage characteristics of the electrode pair. A signal is then selected and applied to the electrodes to operate beyond the transition. Periodically, a varying signal is applied to the electrodes and the monitoring process reperformed to determine a new transition and an appropriate signal is selected to operate beyond the transition.