Patellar implant with variable weights for knee repair surgery

A device for repairing a patient patella, the patient patella having a moment of inertia and a center of gravity, the device comprising:

• a plurality of pegs comprising at least two pegs with different weights from each other;
• and a patellar trial piece comprising an articular surface member, a drill guide, and an enclosure attached to a bottom surface of the drill guide, the patellar trial piece and the pegs configured to be attached together through the drill guide, the enclosure configured to cover the attached pegs and the patellar trial piece configurable to correct at least one of the moment of inertia and the center of gravity of the trial piece to correspond to that of the patient patella, wherein the plurality of pegs are fixedly insertable in and removable from the drill guide of the patellar trial piece during a knee repair surgery.

A system for repairing a patient patella, the patient patella having a moment of inertia and a center of gravity, the system comprising:

• a plurality of variable weights comprising at least two pegs with different weights from each other;
• a patellar trial piece comprising an articular surface member, a drill guide, and an enclosure attached to a bottom surface of the drill guide, the patellar trial piece and the variable weights configured to be attached together through the drill guide, the enclosure configured to cover the attached variable weights, and the patellar trial piece configurable to correct at least one of the moment of inertia and the center of gravity of the trial piece to correspond to that of the patient patella to achieve optimal tracking and full range of motion;
• and a patellar implant with embedded weights, wherein the embedded weights correspond to the at least two pegs with different weights, and wherein a total weight of the patellar implant is in accordance with a combined mass of a shaved part of the patient patella.