The number of locking screws predicts the risk of nonunion and reintervention in periprosthetic total knee arthroplasty fractures treated with a nail.

Periprosthetic knee fractures following total knee arthroplasty are increasing proportionally to the number of primary procedures done. We performed a retrospective review of Rorabeck type II fractures treated with a retrograde nail, trying to find the relationship between failure and the number of distal locking screws used. Twenty-six patients were included. The number of distal interlocking screws (patients with one or two distal interlocking screws and patients with three screws) correlated with nonunion (p < 0.1), did not correlate with the malunion rate (p > 0.1) and correlated with the reintervention rate (p < 0.1).