Supracondylar Fracture of the Femur Following Prosthetic Knee Arthroplasty

Sixty-one supracondylar fractures above prosthetic knee replacements in 58 patients were reviewed with a mean follow-up time of 3.7 years (range, 9 months to ten years). The mean interim between arthroplasty and fracture was 2.9 years (range, intraoperative to ten years). Twenty-seven cases demonstrated notching of the anterior femoral cortex. Seventeen patients suffered from a severe neurologic disorder. Group A consisted of 30 patients with 31 fractures treated by open reduction and internal fixation or revision arthroplasty. Follow-up study revealed 25 unions, three malunions, one nonunion, and two above-knee amputations for deep sepsis. Four of 31 patients had increased pain levels or change in ambulatory status postoperatively. Group B consisted of 30 fractures in 28 patients treated by casting alone or traction followed by cast bracing. Follow-up examination showed 17 unions, seven malunions, and six nonunions. Fifteen of the 30 patients had increased pain levels or change in ambulatory status after treatment. Casting produced significant decreases in motion in both groups. The results indicate that this fracture is associated with anterior notching of the femoral cortex and preexisting neurologic disorders. Patients with a supracondylar fracture following prosthetic knee arthroplasty are best managed by secure internal fixation and early motion.