30 results about "Hip resurfacing" patented technology

A method and device are provided in order to achieve desired orientation of an acetabular cup for total hip replacement or hip resurfacing. The method and device utilize preoperative CT, MRI or other scans, 3D computer modeling and a patient specific alignment jig created from CT, MRI or other data and computer 3D modeling. The device allows accurate placement of a drill hole to establish an acetabular axis and placement of an acetabular cup perpendicular to the axis.

Tools and methods for implanting hip resurfacing femoral prostheses along a path defined by the axis of a shaped femoral head surface are described. The prostheses are stemless partial ball components having an outer surface shaped to conform to an acetabular socket and may be a two part design having a mating sleeve component with an internal bore adapted to receive the shaped femoral head. The tools and methods are capable of accurately implanting both one and two piece ball components and sleeves without requiring the prosthesis to have a central stem or the preparation of a stem cavity in the femoral head and neck.

An instrument for guide pin placement in a femoral head and neck of a patient, the instrument having a reference pin guide member and a retrograde pin guide member adjustably attached to the reference pin guide member. The reference guide pin member has a bore configured for use in positioning and guiding an external reference pin. The retrograde pin guide member has a plurality of retrograde pin bores for use in positioning and guiding a retrograde reference pin into the femoral neck and head of the patient using a retrograde approach. If an initial retrograde reference pin is not positioned properly, one of the plurality of retrograde pin bores is used to insert another retrograde reference pin in a more desirable position using a retrograde approach.

The instantly disclosed implant is designed to resurface or partially replace (two versions) the arthritic or osteonecrotic femoral head in an anatomic fashion with maximum fixation, durability and stability. It will serve a wide range of patient ages, arthritic/traumatic deformity, and bone pathologies while providing for high performance activity. The implant has absolute fixation utilizing existing, contoured femoral head bone with or without bone cement/porous texturing, an internal plate with modular head attachment, and advantageously benefit from the concurrent use of precision guided instrumentation. This implant optimizes maximal femoral head contact with or without porous contact surfaces but does not rely purely on the head for long term stability. This new concept prevents the common failure mechanisms of femoral neck fracture, loosening and malpositioning as well as makes patient bone quality less important for this high performance hip resurfacing implant.

A method of resurfacing a femoral head involves using a chamfered reamer to ream only a top portion of the femoral head above an anterior lateral portion of the femoral head where the retinacular vessels supply blood to the femoral head. As no cylindrical reaming is performed on the lateral portions of the femoral head, damage to the retinacular vessels is avoided. The method thereby preserves femoral head vascularity. A surgical instrument tray for enabling a surgeon to perform this method includes both a reamer and a spherometer for assessing the sphericity of the femoral head to determine whether osteophyte growth on the femoral head is likely to cause femoro acetabular impingement. The instrument tray can also include a tool, such as a bone chisel or burr, for removing the osteophytes to restore the sphericity of the femoral head, rather than removing the osteophytes using a cylindrical reamer.

A method of locating an acetabular cup implant (100) in a pelvis comprises locating a plurality of reference points on the pelvis, defining a target location of the implant relative to the reference points, and placing the implant at the target location. A method of locating a femoral head implant (102) is also disclosed, together with associated guidance systems.

The present invention includes a measurement/assessment technique based upon a collection of angular and distance measurements taken with respect to x-ray visible osteo-anatomical artifacts to arrive at accurate and easily reproducible component placement. In the context of hip arthroplasty surgery the method of the present invention involves determinations, from two different two-dimensional views, of the angles and distances from osteo-anatomical artifacts, to allow a surgeon to approach a hip resurfacing operation with the distance and angular measurements to be translated into actual markings and device settings to be able to accurately ream the femoral head structure, position and affix the femoral cap and acetabular cup components in accordance with the pre-determined distance and angular measurements.

A targeting device for use in hip surgery and more particularly for use in hip replacement surgery or hip resurfacing surgery, which may include minimally invasive surgery. An exemplary embodiment of the targeting device comprises one or more sensor devices, a guide sleeve, a guide sleeve location adjustor, and a computer device with software for receiving data from the sensor device or devices and processing this data so as to determine the location of the centerline of the femoral neck. In other embodiments, the sensor devices are movable so as to obtain data at two or more different radial locations around the femoral neck or angularly spaced in order to obtain data in the anterior-posterior plane and in the superior-inferior plane. Moreover, the sensor devices can be placed on retractable arms.

A scalable modular hip resurfacing arthroplasty system includes (1) an alignment guide for precise guide pin insertion, (2) a modular cannulated cylindrical reamer assembly for accurate femoral head cylindrical reaming and central bone channel drilling, (3) a saw guide for an accurate femoral head osteotomy, (4) a soft tissue protector with a stepped design to shield and retract tissues, (5) a hip retractor that seats onto a prepared femur, (6) an outer hole drill guide aiding drilling of peripheral holes, and (7) a femoral resurfacing implant with a cap portion and central stem adapted for multiple modular attachments including plates. A method for preparing the proximal femur for hip resurfacing with novel stepped cylindrical femoral head osteotomy and central bone channel drilling, leaving an intact collar of cortical bone above the femoral head articular rim.

A femoral component (1) for a hip resurfacing arthroplasty comprising a femoral cap (2), adapted to engage with a cup (3) which is set into a pelvic bone (15), the femoral cap having a convex (4) surface and a concave surface (5), and a stem (6) attached to the concave surface of the femoral cap, characterised in that at least a portion of the stem is composed of a soluble material.

A device for guiding a drilling of a femoral head of a femur in femoral head resurfacing comprises a body defining a guide channel adapted to receive and guide a drilling component therein. Arms are pivotally connected to the body and biased toward one another, the arms each having a contact end extending below the body, the contact ends adapted to contact a femoral neck when the body is in a hovering position relative to the femoral head. Sensors produce a signal indicative of an orientation angle of each of the arms relative to the body. A processor unit calculates the orientation angles of the arms from the signal, and evaluates from the orientation angles an alignment of the body relative to the femur. A visual output produces a visual signal representative of said alignment. A method for aligning a drill guide device on a femur for subsequent drilling a femoral head with a guide channel in the drill guide device is also provided.

A variable hip resurfacing implant which allows for varying configuration options to account for characteristics of underlying degenerative hip joint disease and for both un-cemented and cemented application. The variable hip resurfacing implant generally includes a femoral head portion, bearing surface, outer rim, inner planar surface, central stem, and a central stem threaded hole.

A veterinary hip resurfacing prosthetic system includes a femoral cap and an acetabular cup. The cup shell has a thickness of less than 2 mm and a liner in the shell has a thickness of less than 2.5 mm in order to accommodate a larger femoral cap. Further included are features for preventing rotation of the liner relative to the shell, for releasably locking the liner in the shell, and for accessing the liner to remove it from the shell.

The present invention is an implant meant for hip resurfacing arthroplasty, a surgical reconstruction performed on patients with diseased hips, during which the surgeon replaces the surface of the femoral head with a polished metallic spherical shell. The presented implant consists of a metallic shell (1) with a polished hemispherical outer surface and an inner hemispherical concave surface, which possesses a trunnion (2) with a thread (4) and thin meridian fins (3) and is fully metal porous coated for osseointegration between implant and bone. The presented implant is fitted onto the appropriately contoured femoral head and is stabilized by means of a preload tension wire (5), which drills the femoral head and neck and exits the greater trochanter.; The wire attaches proximally to the thread (4) of the trunnion (2) of the shell and distally to a nut-washer combination (6), by the tightening of which establishment of preload is achieved.

A fixation technique is provided whereby a solid metal acetabular cup, such as is used with hip resurfacing implants, or so called “metal on metal” bearings used with traditional total hip replacement, which do use supplemental screw fixation, can achieve immediate fixation to the acetabulum using a acetabular fixation screw, which couples to an acetabular metal cup by way of a precision taper coupling (tapered interference fit) between the fixation screw and the acetabular cup. Under normal loading, the cold weld achieved between the two surfaces is stable, and disassociation between the two metal surfaces can be achieved only with significant force.

The present invention disclosed resolves the main problems of bone-sparing hip resurfacing surgery by using only an acetabular component in which the femoral head articulates, being only shaved to a spherical shape and cleared of osteophytes that could impinge on the acetabulum and so restrict the range of motion. The inner surface of the resurfacing cup is aspherical in shape creating an annular contact with the femoral head. The inner, articulating surface of the cup (10) is ADLC or pyrolytic carbon coated to reduce friction and wear of the femoral head. The surgical approach is well developed with surgery time significantly reduced by avoiding the use of the femoral resurfacing component. The cup is preferably of the double¬shell type for cementless fixation, but it can also be made as a single shell for cementless or cemented fixation. Should a revision surgery due to wear of the femoral head become necessary, the cup can be retained and combined with a dual mobility femoral component.