Landmarks for cast application and the importance of adequate padding
Proximally, the posterior edge of the cast lies distal to the popliteal fossa, laterally it remains distal to the neck of the fibula and the at risk common peroneal nerve. Anteriorly, it can approach the tibial tubercle. An easy landmark is 3-4 fingerbreadths below the popliteal crease. All toes should be visible dorsally. The common peroneal nerve, superficial to the proximal fibula, may be compressed by the top of a below-knee cast. Adequate padding and cast molding (posterior flattening and apex anterior angle) help to minimize this risk.