Case report : femoral shaft fracture resulting from femoral tracker placement in navigated TKA

Abstract

Computer-assisted navigation is a surgical tool that may decrease malalignment outliers in TKA. With any new surgical technique, there is the possibility of unexpected complications that raise caution. We report two patients with displaced femoral fractures at optical tracker pin placement sites created for routine performance of navigated TKA. Our experience suggests single bicortical 5-mm pins placed in the femoral shaft have the added risk of creating a stress riser leading to the potential for fracture. Females may have a higher risk for this complication. We believe bicortical pin fixation in the femur or tibia no longer is indicated.

Fig. 1A–D

(A) Anteroposterior and (B) lateral radiographs of a 71-year-old woman show a displaced distal femoral fracture at the optical tracker pin placement site 9 weeks postoperatively. (C) Anteroposterior and (D) lateral radiographs show the fracture after retrograde intramedullary nailing.

Fig. 2A–D

(A) Anteroposterior and (B) lateral radiographs of a 77-year-old woman show a displaced distal femoral fracture at the optical tracker pin placement site 3 months postoperatively. (C) Anteroposterior and (D) lateral radiographs show the fracture after retrograde intramedullary nailing.