Treatment of femoral fracture above a knee prosthesis: 18 cases followed 0.5-14 years

We reviewed 16 patients who sustained 18 fractures above a total knee prosthesis. 5 fractures were undisplaced and were treated with either skeletal traction or a plaster cylinder. 3 did well, 1 patient suffered a cerebral vascular accident while still in plaster and 1 patient died of heart failure while on skeletal traction. 7 displaced fractures were treated initially with skeletal traction. 1 patient had a nonunion of the fracture and 2 a malunion and malfunction of the knee. 4 underwent various operations later because of malalignment and nonunion of the fracture with poor functional results. 6 displaced fractures were treated with immediate internal fixation. 5 recovered well and returned to pre-fracture activities. 1 patient's plate broke and further surgery was needed. We conclude that displaced fractures above a knee prosthesis should be treated with immediate stable internal fixation and early mobilization. Nonoperative treatment was satisfactory only for minor undisplaced fractures.