Patella Preparation

The easiest time to prepare the patella is after all tibial and femoral cuts are made, but prior to trial placement. In some cases, the patella is cut just after arthrotomy to facilitate exposure. Rotate the patella to 90°, measure its thickness, and determine the appropriate diameter implant.

Resurfacing (Onlay) Patella

1. Place two Kocher clamps just proximal and distal to the patella to hold the patella’s position.
2. Cut the patella using an oscillating saw.
3. Drill the peg holes using the drill guide.

Biconvex (Inset) Patella

1. Select the correct patellar reamer collet and slide it into place on the patellar reamer guide.
2. Attach the patellar reamer guide to the patella and tighten the reamer guide on the patella. (Figure 18)
3. Use the calipers to measure patella thickness.
4. Attach the patellar depth gauge for the selected patella design to the reamer guide.
   
   The reaming depth for each design is as follows:
   • Biconvex patellae: 13mm
   • Resurfacing patellae: 9mm
   • All-poly with Flex-Lok* peg: 15mm
   
   
   
5. Attach the patellar reamer dome and patellar depth stop to the patellar reamer shaft. Before this assembly is attached to drill, lower it through the patellar reamer guide until the reamer dome contacts the patella.
6. Swing the patellar depth gauge around so that the "claw" surrounds the patellar reamer shaft.
7. Lower the patellar depth stop until it contacts the patellar depth gauge and automatically locks in place.
8. Remove the depth gauge.
9. Attach the patellar reamer assembly to power equipment. Ream the patella until the depth stop engages the patellar reamer guide.