The Efficacy of Dynamization of Static Interlocking Intramedullary Nailing as A Trial Leading to Bony Union of Femur Shaft Fracture

Kim, Byung Soon; Cho, Duck Yeon; Yoon, Hyung Ku; Han, Soo Hong; Kim, Jin Yong; Kim, Yong Wook

Abstract

PURPOSE: To evaluate the efficacy of dynamization of static interlocking intramedullary nailing as a trial leading to bony union of femur shaft fracture, delayed union of femur shaft fracture underwent dynamization were investigated. MATERIALS & METHODS: Between april 1995 and December 2000, 162 patients were treated static interlocking intramedullary nailing, 14 patients were selected who had underwent dynamization. The average age was 39 years old (range 24 to 61), they were 11 men and 3 women. The type of fractures were two communited, seven segmental and five simple fractures. Dynamization were done by removal of proximal or distal interlocking screw. We defined complete bony union as radiological and clinical bony union. Also we measured leg length discrepancy and angulation by radiologic parameters.
RESULTS
Of the 14 patients who showed delayed union, 7 patients were noted successful bony union by dynamization, and of the 7 patients who failed union by dynamization, 6 patients were noted bony union by supportive operative treatments(bone graft : 4 patients, nail exchanging : 1 patient, both method 1 patient). One patient was seen nonunion state because of patient's refusal of treatment. 7 patients who were noted successful bony union by dynamization had 2 degrees~6 degrees(average 4.14 degrees) varus-valgus angulation and 4 degrees~9 degrees(average 6 degrees) AP angulation, and 3 of the 7 patients showed leg length discrepancy(LLD) greater than 2 cm. The other 7 patients had 2 degrees~5 degrees(average 3.57 degrees) varus-valgus angulation and 3 degrees~7 degrees(average 5 degrees) AP angulation, and 2 of the 7 patients showed LLD greater than 2cm. Of the 14 patients, 5 patients showed limping.
CONCLUSION
Dynamization of intramedullary nainling is a simple and valuable method for improving bony union of femur shaft fracture in the case of delayed union. But if the delayed unions are seen due to large bone defect, supportive operative treatments (bone graft, nail exchanging etc.) to avoid significant complica-tion(shortening and angulation) is needed.