Abstract: A hip joint prosthesis is formed of a coil spring having a middle section bounded by first and second opposite ends, with one of the two ends configured as a femoral fixing end and the other of the two ends configured as an acetabular fixing end. A central axis of the coil spring extends between the two opposite ends, providing a freely movable, flexible central coil linking the two ends.

Abstract: A hip prosthesis device including a femoral stem, the femoral stem including an elongate stem sleeve having a blind hole extending in a longitudinal direction and a hole opening at an upper frontal end of the stem sleeve; a stem core having an elongate stem shaft inserted in the blind hole and slidable in the longitudinal direction, a neck having a lower neck portion and an upper neck portion, a lower end of a lower neck portion attached to an upper end of the stem shaft, the upper neck portion attachable to a femoral head; a shock absorber mechanism operatively provided between the stem shaft and the stem sleeve to act against a downwardly directed longitudinal sliding motion of the stem shaft relative to the stem sleeve; and a closure cap positioned to close the hole opening with a through hole which the neck extends with its lower neck portion.

Abstract: A transdermal intraosseous device for coupling a bone stump to an external prosthetic device includes a bone fixator, an external connector and a plurality of modular interface components. The bone fixator includes a proximal portion configured for anchoring into the bone stump of the patient and a distal portion including a base collar configured for subcutaneous implantation. The external connector has a distal portion for coupling to the external prosthetic device and a proximal portion for coupling to the distal portion of the bone fixator. Each interface component can be removably coupled to the base collar and has different size and shape to provide a surgeon-selected transition between the prosthetic device and the patient's skin.

Abstract: A device for containing bone graft material includes a mesh outer sleeve extending longitudinally from a proximal end to a distal end and sized and shaped to correspond to a profile of an outer surface of a target bone. The outer sleeve includes a longitudinal slot extending along a length thereof. The device also includes a mesh inner sleeve connected to an interior surface of the outer sleeve via at least one strut so that a bone graft collecting space is defined therebetween. The inner sleeve is sized and shaped to correspond to a profile of a medullary canal of the target bone. In addition, the device includes an interstitial mesh extending radially away from an exterior surface of the inner sleeve toward an interior surface of the outer sleeve to hold graft material in the bone graft collecting space.

Abstract: A load bearing implant comprising a femoral implant stem made from a bio-compatible metal having an elastic modulus far greater than that of natural bone. When the implant heals within a bone cavity, the implant essentially carries substantially the entire load. Transfer of load to the surrounding bone tissue is lost due to lack of use after healing. Flexing a stiff implant applies a large load at the implant distal end. The bone cortex is thereby allowed to thicken, causing thigh pain long after implant healing. The femoral implant has a bone ingrowth coating on the proximal end, allowing firm attachment of the implant in the bone cavity. The distal end has a central aperture and a helical machined groove that permits flexing of the distal portion of the femoral implant stem. This flexing occurs in a manner similar to surrounding bone tissue, preventing thigh pain.

Abstract: An artificial cement-less hip prosthesis stem comprises an inner construct 7 which reacts with a load acting on a hip joint and an outer construct 8 for transmitting the load acting on the inner construct to a femur 1. The inner construct has an inner body 7B which reacts with the load transmitted from a neck 7A. The outer construct has both an outer body 8A which is bell mouth-shaped toward an epiphysis so as to surround the inner body 7B and a leg 8B extending toward a medullary cavity. The torsional rigidity given to the proximal end and the distal end of the outer body 8A and the leg 8B is regulated so as to be lower than the torsional rigidity given to an intermediate portion 18 of the outer body 8A.

Abstract: An intramedullary fixation device and associated method. The intramedullary fixation device includes a first intramedullary component having a first bone-attachment end and a first elongated member, a second intramedullary component having a second bone-attachment end and a second elongated member, and a compliant member coupling the first and second intramedullary components for applying bone-compressing stress. The second intramedullary component defines a sleeve such that the first elongated member can pass therethrough.

Abstract: A femoral stem for hip prosthesis is disclosed comprising: a main body with a mainly longitudinal development and a generally wedge shaped, which is inserted into the femoral canal present in the body of the femur; a central body of a generally trapezoidal shape integral with the main body, located in the proximal zone of the femur; an appendix projecting from the central body provided with a terminal pin receiving spherical head of joint into the cotyle belonging to the prosthesis and inserted into the acetubular zone of the pelvic bone. The main body and the central body are defined by a shaped surface on one side and a mixtilinear surface on the opposite side from which a shaped notch is starting involving the central body and extending up to the proximity of the projecting appendix.

Abstract: An endoprosthesis utilizes a biomechanical structure based on the lever model of first degree. Contrary to the widespread practice, the inventive structure has a stem placed inside the femur bone, which is not rigidly attached to this bone. Accordingly, the bone, following its known tendency to slightly pivot away from the medial plane of the body in response to the loads, does not directly contact the stem. The neck portion experiences even greater loads then the stem. The supporting anchor has a region extending laterally from the stem and pressing against a supporting surface of the housing, which also extends laterally from the body of the housing. Since the stem, supporting anchor and neck are typically constitute a one-piece component, the lateral surfaces of the supporting anchor and housing are in continuous frictional contact during displacement of the stem and housing relative to one another.

Abstract: A prosthetic implant having a fixation stem with varying stiffness is disclosed. The stem comprises an elongated core and segments extending outward from the core. The segments are spaced apart so as to define transverse grooves surrounding the core between adjacent segments. The longitudinal length of the grooves, and the materials used for the core and the segments are selected such that the stiffness of the stem varies from the proximal end to the distal end. Typically, the stiffness of the stem will be lower at the distal end such that the distal end of the stem bears less force when loaded and thereby transfers more load to the proximal end of the stem, which has a higher stiffness. As a result, stress shielding, in which the load bypasses the proximal end of the stem, is minimized and bone resorption adjacent the proximal end of the stem is decreased.

Abstract: A hip joint endoprosthesis which comprises a shank, a joint ball at the upper end region of the shank, a joint socket, within which the joint ball is mounted to be rotationally movable, and a joint gap present between the joint ball and the joint socket. The joint socket and/or the joint ball has in the interior thereof a closed liquid-filled, gas-filled or gel-filled region. This is separated from the joint gap only by a thin, resiliently deformable edge region of the joint socket or joint ball.

Abstract: Skeletal implant of the type to be used for connecting at least two elements of the skeleton. The implant has two parts. Each of the parts is capable of being connected to one of the elements. The implant also uses at least one shock-absorbing device located between the at least two parts. The shock-absorbing device has an adjustable coefficient of resistance.

Abstract: The present invention provides a tibial tray assembly for attaching within a cavity formed in a tibia. The tibial tray assembly includes a main body, an anchor, and a compliant portion disposed between the main body and the anchor. The main body includes a tibial tray that is operable to engage a prepared tibia surface. The anchor is operable to be retained within the cavity formed in the tibia and includes an attachment mechanism located within the cavity and operable to fixedly attach the anchor within the cavity formed within the tibia. The compliant portion disposed between the main body and the anchor is operable to be expanded and contracted.

Abstract: A prefabricated joint is employed for the prosthetic joint. The joint includes prefabricated socket, ball, and capsule. The capsule is attached from the ball to the socket. The capsule seals the area between the ball and socket and prevents wear debris from entering the body cavity. In the case of the hip joint, the doctor need only attach the prefabricated unit to the femoral unit to connect the prosthetic joint after the prefabricated unit and femoral unit have been placed into the acetabular and femur, respectively.

Abstract: A joint prosthesis comprising at least a first and a second load carrying member, the first load carrying member being substantially more shock absorbing and resilient than the second load carrying member.

Abstract: A bone attachment assembly for a remaining portion of a long bone diaphysis following resection is provided. The assembly includes a main body, means for anchoring the device with respect to the remaining bone portion, such as an anchor body, and means for attaching the main body to the means for anchoring. The means for attaching the main body may preferably be in the form of one or more washer springs retained upon a connecting rod attached to the means for anchoring. The assembly may be connected to an orthopedic appliance, an interposed orthopedic appliance connected to a second bone attachment assembly, or a transcutaneous bar for attaching an external appliance. A reaming device for creating an intramedullary cavity, a guide device for guiding an aperture-forming procedure in a remaining bone portion, and a milling device for shaping an interface surface of the bone in a preselected geometry are also provided.

Abstract: A femoral stem for use with an artificial hip joint assembly having helical cuts formed in the shaft thereof. The helical cuts form a restoring force spring-like shock absorbing geometry which permits the rigid metal material to grossly conform to the elastic modulus of the patient's bone. This femoral stem reduces the shock loading and attending pain associated with activities, such as standing, walking, and descending stairs, which often plague hip replacement patients.

Abstract: A modular hip implant that can be custom fit to an individual patient, including a shock absorption system that absorbs compressive stresses that are imparted to the implant. The size of the femoral ball member, size of the femoral stem, femoral neck length, and tension in the shock absorption system are all individually adjustable parameters, depending on the particular patient. A unique coupling member houses a modular spring mechanism that serves as the shock absorber. The coupling member is received into the ball member to an adjustable depth, the adjustment of which varies the length of the femoral neck. The length of the femoral neck can be adjusted during surgery without requiring additional parts.

Abstract: A device is provided for anchoring an endoprosthesis in a bone, for example a thigh portion of a hip joint endoprosthesis in a femur. The device is configured in the form of a quiver-like receptacle which can be implanted in the bone for receiving a shaft of the endoprosthesis. The receptacle comprises an inner wall enclosing the shaft and an outer wall disposed at a distance therefrom. A space between the inner wall and the outer wall is filled with a medium, in which an externally applied pressure is uniformly distributed substantially to all sides for damping impacts exerted on the endoprosthesis.

Abstract: A bone attachment assembly for a remaining portion of a long bone diaphysis following resection is provided. The assembly includes a main body, means for anchoring the device with respect to the remaining bone portion, such as an anchor body, and means for attaching the main body to the means for anchoring. The means for attaching the main body may preferably be in the form of one or more washer springs retained upon a connecting rod attached to the means for anchoring. The assembly may be connected to an orthopedic appliance, an interposed orthopedic appliance connected to a second bone attachment assembly, or a transcutaneous bar for attaching an external appliance. A reaming device for creating an intramedullary cavity, a guide device for guiding an aperture-forming procedure in a remaining bone portion, and a milling device for shaping an interface surface of the bone in a preselected geometry are also provided.

Abstract: A bone attachment assembly for a remaining portion of a long bone diaphysis following resection is provided. The assembly includes a main body, an anchor for anchoring the device with respect to the remaining bone portion and an attachment portion for attaching the main body to the anchor. The assembly may be connected to an orthopedic appliance, an interposed orthopedic appliance connected to a second bone attachment assembly, or a transcutaneous bar for attaching an external appliance. A reaming device for creating an intramedullary cavity, a guide device for guiding an aperture-forming procedure in a remaining bone portion, and a milling device for shaping an interface surface of the bone in a preselected geometry are also provided. In the method of the present invention, a cavity is created within a remaining bone portion using the reaming device. At least one aperture is created using the guide device, and the bone surface is milled to a preselected geometry using the milling device.