Usefulness of bilateral plate fixation for periprosthetic distal femur fracture after total knee arthroplasty

INTRODUCTION: Recently, good results of locking compression plate (LCP) have been reported in the case of fixation using plate, but when fractures extend too distal over the proximal border of femoral component, operations are highly challenging. PRESENTATION OF CASE: Author reports two cases that couldn't get reliable fixation by LCP alone because of poor bone quality with chronic infection and far juxta-fracture of prosthesis. Fractures were fixed to the medial and lateral sides of the distal femur with LCPs and were healed successfully. DISCUSSION: Indirect healing (endochondral bone formation) using anatomical alignment and bridge plating using LCP is usually used rather than direct healing (intramembranous) through anatomical reduction and rigidly stable fixation for periprosthetic distal femoral fracture. Proper flexible fixation is helpful for indirect bone healing through the callus formation, but too flexible fixation cannot maintain fracture fragments until the callus formation provides sufficient stability. Medial parapatella approach for additional medial side plating have many advantages that it can confirm the screw length which not penetrate intercondylar box or medial cortex, and can check component stability, rotation, wear of the polyethylene insert. CONCLUSION: Bilateral plate fixation through additional medial parapatella approach is useful method for obtaining secure fixation to poor bone quality or extremely distal femoral periprosthetic fracture.