186 results about "Left femoral head" patented technology

A replacement device for resurfacing a joint surface of a femur and a method of making and installing such a device is provided. The custom replacement device is designed to substantially fit the trochlear groove surface, of an individual femur. Thereby creating a "customized" replacement device for that individual femur and maintaining the original kinematics of the joint. The replacement device may be defined by four boundary points, and a first and a second surface. The first of four points is 3 to 5 mm from the point of attachment of the anterior cruciate ligament to the femur. The second point is near the bottom edge of the end of the natural articulatar cartilage. The third point is at the top ridge of the right condyle and the fourth point at the top ridge of the left condyle of the femur. The top surface is designed so as to maintain centrally directed tracking of the patella perpendicular to the plane established by the distal end of the femoral condyles and aligned with the center of the femoral head.

An Extramedullary system of alignment for total knee arthroplasties uses a small diode laser at the center of the knee adjustable to the longitudinal axis of the femur to triangulate the center of the femoral head. It utilizes a V-Frame positioning device that fits into the distal femoral intercondylar notch and is tangent to the articular surfaces of the notch. It is also parallel to the anterior femoral cortex by using a removal tongue flange that sits flat on the filed surface of the anterior cortex. This prepositions the Distal Femoral Resector Guide within a few degrees of the center of the femoral head. An adjustment knob on the V-Frame pivots the distal femoral resector guide to the exact center of the femoral head for that particular patient accomplishing fine adjustment of the longitudinal axis of the femur. There is only one position where the laser beam will go through the center of the target no matter where you position the leg and that is when the target's bulls-eye is exactly over the rotational center of the femoral head. Since the laser confirms this position, the surgeon is assured that the alignment is accurate. The Distal Femoral Resector Guide is then fixed to bone with fixation pins and the resection made with a power saw. The laser is moved to the target mount to act as a longitudinal “laser ruler” for the remainder of the operation.

A femoral head prosthesis assembly and operation instruments thereof. The operation instruments include a hollow femoral neck holder with a configuration adapted to the surface configuration of the femoral neck and a shaper blade for cutting a replacement end of the femur into a predetermined configuration. A guide tube is disposed on a top face of the femoral neck holder. A transverse slot is formed on the femoral neck holder for indicating a femoral head cutting line. The femoral head prosthesis assembly includes a cap body and an artificial femoral head. A root section of the cap body has an inner surface in conformity to the surface of the femoral neck. A top section of the cap body has a cross section adapted to that of the replacement end. The cap body can be precisely securely bonded with the replacement end of the femur.

The surgeon grasps the jig by its handle and manipulates the head of the jig through the patient wound and onto the femoral neck. The head of the jig includes jig location means in the form of an elongate rod which acts as a spacer. The spacer has an end which abuts the trochanteric fossa so as to position the slot of the jig at the required position, which is between 5 mm and 25 mm, and most preferably 15 mm, from the trochantic fossa. Additional jig location means are provided by a surface adapted to receive a bone formation. This surface is provided by contours on the base of the head which are adapted to mate with contours of the femur. The slot is oriented generally perpendicularly to the elongate dimension of the rod. The slot functions as a surgical tool guide means which is positioned by the jig at the correct position for osteotomisation of the neck. Advantageously, osteotomisation takes place while the femoral head is still disposed within the acetabulum.

A femur fixture for a hip-joint prosthesis comprising an intraosseous anchoring structure of a generally circular cross-section for screwing laterally into a complementary bore drilled laterally into the neck of a femur after resection of the femur head to an anchored position. The intraosseous anchoring structure has a proximal end, a distal end, a relatively short frusto-conical proximal section at the proximal end, and a proximal cylindrical section having a screw thread profile thereon. The proximal cylindrical section extends from the frusto-conical proximal section towards the distal end of the anchoring structure. The frusto-conical proximal section and the proximal cylindrical section each being dimensioned so as to bear against the cortex of the femur neck when the intraosseous anchoring structure is in the anchored position. The invention also relates to a set of such femur fixtures, wherein the frusto-conical proximal section and the proximal cylindrical section of each fixture in the set have different dimensions, whereby the fixture in the set having the frusto-conical proximal section and the proximal cylindrical section of correct size for abutting the cortex of the femur neck of a particular patient can be selected for use in that patient.

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.

A prosthetic hip-joint includes: a. a prosthetic acetabulum cup for implantation into a pelvis; b. a prosthetic femoral assembly which includes: i. a ball-shaped femoral head that during implantation becomes located within the cup; and ii. a femoral stem that is fixed at a first end to the head, and that has a second end distal from the first end which is adapted for implant into a medullary canal of a femur, and c. a liner assembly adapted to he secured to the cup and is also adapted to receive and to constrain the head against dislocation. In one aspect the hip-joint permits the head to rotate through an angle which exceeds at least 153 degrees while concurrently constraining the head against dislocation. In another aspect the hip joint constrains the head a dislocation by a preestablished amount of force which is adjustable during implantation thereof.

A femoral head offset and neck length required in a femoral component to be engaged with an acetabular component are determined for establishing appropriate hip mechanics in a prosthetic hip joint. Alternate selected sleeves of different lengths are interposed between a trial femoral head component and a trial femoral stem component movable relative to one another to admit each selected sleeve, interoperatively, for serial trialing to determine an appropriate trial distance, the appropriate trial distance corresponding to the required femoral head offset and neck length in the prosthetic hip joint.

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.

Disclosed therein is a big femoral head and femoral head surface replacement, which are used for hip osteoarthritis and vascular necrosis of femoral head. As a person get older and aged, the weight bearing hip joint is indispensably changed to osteoarthritis and sometimes showed avascular necrosis of the femoral head with unknown etiology. The deformed femoral head and hip joint should be replaced with the THA. Till now, the total hip replacement is performed in such a way that the necrosed femoral head and a healthy femoral neck are all removed and a femoral stem is inserted into the marrow cavity, and in this case, a small femoral head causes a reduction of a range of motion and dislocation of the hip joint occasionally, and osteolysis due to abrasion of plastic acetabular liner. In case of a conventional femoral head surface replacement (hereinafter, called “conventional FHSR”), a complication of femoral neck fracture and could not combined use with conventional THA. Recently, hard bearing system such as metal on metal THA or ceramic on ceramic THA without using plastic has been introduced to solve the problem of osteolysis due to abraded plastic particles generated when the THA is worn out as time goes. But there also have many problems as a limited range of motion, resected normal femoral neck and difficulties of rereplacement of the femoral stem. Because of the big femoral head or the FHSR can increase the range of motion and lower dislocation rate these devices are gradually widespread in young active person and Asian peoples. This invented design of the modularity gives the convenience to the surgeon and economically lower burden to patients to use of the FHSR and big femoral head system. The related accessory showed initial stability of the FHSR during operation and prevent from femoral neck fracture in follow-up periods.

A joint replacement prosthesis and procedure reduce the number of steps to complete a joint replacement. The joint replacement prosthesis comprises a ball and socket unit that fixes the ball in the socket prior to surgery. The unit is coupled to a bone structure in the patient and is coupled with a prosthesis that is fixed to another bone of the patient, such as a femoral implant fixed in a femur and providing a coupling at the end of a neck portion that is easily fit into a femoral head and acetabulum unit. A tether may be used to retain the ball in the socket and/or the ball may be retained by extension in the socket that do not restrict patient motion.

An implant is provided for replacing the proximal portion of a femur having a substantially intact natural femoral neck and a lateral side opposite the femoral neck, with a bore extending from the femoral neck through a lateral side of the femur. The implant comprises a sleeve having a flange for engaging a proximally facing resected surface of the neck surrounding the bore in the femur and having a bore with an inwardly tapered conical portion. A shaft member having a longitudinal axis, a distal end, and a proximal end is placed in the bore through the femur. The shaft member has an intermediate conically tapered male portion for coupling to the conically tapered bore of the sleeve and a proximal end having a conically tapered portion. A head member having a distal end and a proximal substantially-spherical portion and a tapered recess is configured for positioning in a natural or prosthetic hip socket.

An external proximal femoral prosthesis for total hip arthroplasty (THA) is described, which fundamentally comprises a shell configured a hollow, thin-wall, asymmetric bell shape and a plurality of tension anchor means. An inner transverse cross contour of the shell forms a cavity, which could be affixable to a profile of outer surface of the area of neck, trochantic bed and calcar of the proximal femur. A neck portion of the shell is compatible with acetabular components (ball and cup). The prosthesis is mechanically fastened by tension anchor means during the operation and further biologically secured by in-growing bone through the side holes on the shell wall and into its interior coating surface of implant wall thereafter. The loading force on the femoral head would be well transferred and distributed on the shell and then directly conducted into the cortical bone of the femoral shaft therearound.

Femoral head modular resurfacing systems are described. The systems primarily include a head component and a stem component. The configuration of the head component and stem components allow for minimum invasiveness into the femur head region, thus conserving greater amounts of bone tissue than would be possible with conventional hip replacement systems. The systems also provide for various angles and offsets to be achieved between the systems and the femur head. The systems are useful in partial hip replacement procedures, as well as total hip replacement procedures, in which case an optional acetabular component would also be employed.

A corrective element for the articulation between the femur and the pelvis, comprising a contoured body that can be inserted, without dislocation of the head of the femur, in the iliac acetabular region after incision of the articular capsule; the contoured body has a smooth outer surface that is substantially adapted to the iliac acetabular region and an inner surface that forms a seat for accommodating the femur head.

A femoral neck fixation prosthesis and method of using same which reduces bone loss and the avoids the other shortcomings of the prior art by allowing the fixation of a stable femoral head replacement while reducing the amount of the femur which must be reamed for the insertion of the prosthesis. The preferred embodiment provides that the femoral head is attached to a fixation prosthesis, which extends coaxially through the canal of the femoral neck, into the femur, and is then attached to the opposite lateral wall of the femur. In this manner, the prosthesis serves to imitate the original structure of the femoral neck. No other support members, either crosspins or arms extending into the length of the femur, are required.

A manufacturing method for a posterior column lag screw 3D navigation module used for acetabulum fracture comprises the following steps that A, according to simulation reestablishing, 3D reestablishing is performed according to pelvis thin layer CT scanning data of an object with the acetabulum fracture so as to obtain an original 3D reestablished model, on the basis of the original 3D reestablished model, fracture block division is performed along the fracture line, and the femur head is removed so as to obtain a fracture block separation model, and on the basis of the fracture model, a single fracture block 3D space position is adjusted to recover the normal anatomic form of the acetabulum, so that a fracture reduction model is obtained; B, according to virtual posterior column slag screw implanting simulation, on the basis of the fracture reduction model, a posterior column slag screw implanting fracture reduction model is simulated with a cylinder on the fracture reduction model; C, according to obtaining of a navigation module simulation body, the navigation module simulation body is established according to the cylinder, so that the navigation module simulation body with screw channels is obtained; D, the navigation module is obtained through 3D printing. The manufactured navigation module has the advantages that the manufacturing technology is simple, precision is high, and safety is good.