Trial Placement

Femoral and Tibial Trialing

1. Insert thin bent Hohmanns laterally and medially (an Aufranc retractor can be placed posteriorly to sublux the tibia forward if necessary) and place the tibial trial.
2. Flex the knee to 90° and place the femoral trial.
3. Use the appropriate insert trial (begin with a 9 mm trial) to determine stability and alignment.
4. Perform a trial range of motion. The alignment marks on the front of the femoral and tibial trials should line up. The quick connect handle may be attached to the tibial trial and used to set the appropriate rotational alignment.
5. Extend the knee fully with the handle attached to the tibial trial. Pass the extramedullary rod through the handle to assess full leg alignment. Mark correct tibial rotational alignment on the anterior tibia using a cautery knife. Alignment can be checked with the spacer block. Since the spacer block has one end for flexion and one for extension, ensure the appropriate end is used.
6. Determine whether a porous or nonporous tibial implant will be used. Select the appropriate tibial fin punch to prepare the fins and punch through the tibial trial.

Note: If the tibial bone is sclerotic, begin the fin slot with a burr or thin saw blade before using the fin punch to prevent tibial fracture.

Patellar Trialing

1. Place the patellar trial into the prepared patella.
2. Perform a trial range of motion to assess patellar tracking. With cruciate retaining knees, medial-lateral placement of the femoral trial can be adjusted to optimize patellar tracking.
3. For cruciate retaining femorals, drill the femoral lug holes through the femoral trial with the femoral lug drill.
4. Remove the tibial trial. Attach the end of the universal extractor to the femoral trial. Remove the femoral trial. Use a towel clip to remove the patellar trial.