Smith + Nephew

Smith & Nephew Richards Inc.

Tim Vendrely

Thomas Andrew Carls

Leo A Whiteside

Chris E Johnson

John K Steele

Khosrow Naraghian

Tony Melkent

John Steele

The method of implanting a femoral and a tibial knee prosthesis and instruments for surgically implanting the femoral and tibial prosthesis component as disclosed. The method includes the formation of a plurality of surgical cuts on the patient's distal femur. A trial tibial prosthesis is then fitted to the surgically prepared distal femur. The trial prosthesis has a femoral articulating surface and a non-articulating surface that fits the patient's distal femur at the surgical cuts. A surgeon then forms a transverse cut on the patient's proximal tibia. The surgeon places a tibial trial prosthesis on the patient's proximal tibia, the trial prosthesis including a tibial trial stem that fits the patient's intramedullary canal, a tibial trial metallic tray or plate, and a plastic trial insert that fits the tibial tray or plate. The plastic insert includes a tibial articulating surface that can articulate with the femoral articulating surface. The respective articulating surfaces are placed in contact and the surgeon then moves the patient's knee through a full range of motion. During this movement of patient's knee through a full range of motion, the surgeon uses a lever that is attached to the trial tibial prosthesis to rotate the trial tibial prosthesis about its stem. The surgeon can try different rotational positions of the tibial trial prosthesis each time moving the knee through a full range of motion to ensure proper orientation and an accurate fit.

Tibial trial prosthesis and bone preparation system

A trial femoral prosthesis for use in knee joint replacement surgery includes a trial prosthesis body that is generally J-shaped. The prosthesis body provides a distal articulating surface and a proximal non-articulating surface. The articulating surface includes medial and lateral condylar portions, a distal portion, and an anterior portion. An elongated stem extends from the distal non-articulating surface for anchoring the trial prosthesis to the intramedullary canal of the patient's femur. Wedge trial insert members are connectable to the trial prosthesis body at the non-articulating surface. The inserts can be of different shape and different thicknesses and can be independently placed on opposite sides of the stem. However, the prosthesis body can be used independently without any inserts. The apparatus assists a surgeon who is going to revise a total knee that had been previously implanted. If a surgeon needs a wedge insert for the trial, a corresponding wedge is placed on the final knee implant. The trial prosthesis body and wedges each provide cutting edges that remove bone in the exact places in order to make the implant fit snugly. The cutting edges shave bone material when the surgeon drives the trial onto the distal femur. If bone needs to be removed in the distal area to accommodate a wedge insert, cutting guide slots are provided in the trial prosthesis body. If bone needs to be removed in the anterior or posterior chamfer area, angled chamfer cutting guide slots are provided in the trial prosthesis body.

Revision femoral trial prosthesis

A distal femoral cutting block apparatus for use in knee surgery includes an instrument body that has generally flat opposing parallel surfaces and a plurality flat peripheral surfaces to form a generally rectangular body. The body provides anterior and posterior surfaces and medial and lateral surfaces. The transverse slot carries a valgus module that is movably disposed in the slot. The valgus module includes a tubular sleeve member having a pair of opposed sides that abut the body at the slot. A portion of the tubular sleeve member is threaded and the threaded portion extends away from the body. An open ended bore extends through the tubular member. The open ended bore of the tubular sleeve member of the module accommodates an intramedullary rod that fits the patient s intramedullary canal. A lock nut engages the threaded section of the module for locking the module in a desired position on the cutting block body by engaging the threaded portion and the instrument body to rigidly affix them together.

Distal femoral cutting guide apparatus for use in knee joint replacement

A method of preparing a patient's proximal tibia with a surgical saw and cutting instrumentation is disclosed. The method of the present invention prepares the patient's proximal tibial to receive a tibial implant. The patient's intramedullary canal is first reamed and then an intramedullary rod is placed in the intramedullary canal as a reference. A first cutting instrument is bound on the rod above the patient's proximal tibia. The first cutting instrument includes a stylus that is used to set the depth of cut by referencing the top of the proximal tibia. The proximal tibia is then transversely cut with the saw by tracking the first cutting guide surfaces with the saw. The first cutting instrument is removed together with its stylus. A secondary cutting instrument is then placed on the rod above the proximal tibia. The second cutting instrument has a cutter at its center for cutting longitudinally into the proximal tibia. A secondary cut is made on the proximal tibia by tracking the secondary cutting instrument and a guide surface provided on the upper end of the cutters that engage the center of the proximal tibia.

Growing community of inventors

Memphis, TN, United States of America

Tim Vendrely