Table 1.

Summary of techniques to avoid patellofemoral complications after total knee arthroplasty

Complication	Technique for avoidance
Patellar maltracking or instability	Femoral component design: extended and deepened trochlear groove Femoral component rotation (3° external rotation compared to posterior condylar axis) Tibial component rotation (central third of tibial tubercle) Place patellar button in medialized position Lateral patellar facetectomy
Patellar clunk	Use femoral component with low intercondylar box ratio Avoid substantial changes in joint line height, decreased patellar thickness or use of small patellar button Maintain posterior femoral condylar offset
Patellar avascular necrosis	Avoid unnecessary lateral retinacular release Avoid excessive patellar reaming
Patellar fracture	Use all-polyethylene patellar component Avoid excessive patellar resection when resurfacing
Anterior knee pain	Attempt to minimize any of the above issues Select appropriately sized femoral and patellar components; preoperative templating to avoid patellofemoral offset changes Circumferential patellar denervation