Fig. 2

For the knees in the FBRE group, the cutting block adapter was placed over the distal femur anterior cortex to register the DCX (a, b). Strategies to avoid pitfalls during DCX registration: insertion of the Schanz pins into the distal femur should be proximal enough (red arrow), and trochlear osteophytes should be removed completely (yellow arrow); intervening soft tissue between the cutting block adapter and the distal femur anterior cortex should be avoided (blue arrow); and retraction of the soft tissue flaps should be adequate (black arrow) (b)