Treatment of the femoral shaft fracture with a curved heat-treated COP clover-leaf nail.

The commonly used straight intramedullary nail has certain limitations and disadvantages. Following radiographic and metallurgical studies we have developed a curved heat-treated clover-leaf nail using a newly developed precipitation hardening stainless steel (COP). The nail is bent with a slot on the convex side and the radius of curvature is 115 cm which corresponds to the anatomical antero-lateral convexity of the human femur. The nail has been satisfactory in clinical use since 1971 and has provided not only more stable internal fixation but also allowed fixation of fractures beyond the middle third of the shaft.