Case #1 - Posterior Stabilized Femoral Component

The following Patient-Matched Implant case illustrates a typical request of the Biomet Patient-Matched Implant team. Joseph Tauro, M.D. requested a one-of-a-kind device for his patient because of an abnormal right distal femur. The femoral condyles are rotated posteriorly or backward compared to a normal femur. Because of this, Dr. Tauro was unable to treat this patient with a standard Maxim® femoral component (Figure 1).


Dr. Tauro supplied a CT scan as well as A/P and lateral radiographs. A three-dimensional reconstruction of the distal femur with the CT scan was created to assist in the development of a custom knee implant design (Figures 2 & 3).



The design proposal template we sent to Dr. Tauro (Figures 4, 5, and 6) show the one-of-a-kind device modified from a standard 70mm Maxim posterior stabilized femoral component. The "one-piece" design includes a stem that is 13.0mm in diameter and 203mm in length. The stem bridges the fracture for support, and was grooved for rotational stability. The anterior flange of the device was extended anteriorly and superiorly to ensure that the anterior cortex would not be notched when making the anterior cut. Because the tibia and patella were anatomically straightforward, standard tibial and patellar components were used with the custom femoral component.




To make this custom device, a wax replica of the design was created. This wax pattern was used in the investment wax casting process to make the cobalt-chrome implant. Delivery of the Patient-Matched device was nine weeks following Dr. Tauro’s approval, although this process now takes 5-6 weeks to complete. Included with the device were the instruments necessary to prepare the femur for the Patient-Matched Implant: a drill guide for mounting the A/P contour block and a custom anterior cutting block.

The postoperative x-rays (Figures 7 & 8) show the successful surgical result.



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