Abstract
Introduction
The free hand technique remains the most popular method for distal locking; however, radiation exposure and increased operative time is a major concern. In an endeavor to overcome this concern, a new technique of distal locking with nail over nail technique is evaluated.
Method
Seventy patients with femoral diaphyseal fractures treated by intramedullary nailing were divided in two groups: distal locking either with free hand technique (group 1) or with nail over nail technique (group II). Group I contained 35 patients (21 males and 14 females) with average age of 44.14 years. Group II contained 35 patients (19 males and 16 females) with average age of 45.7 years. In group II 1.5 mm of over-reaming was performed to avoid the nail deformation while insertion.
Results
Average diameter of the nails used in free hand technique was 11.3 mm and 10.7 mm in nail over nail technique. Precision problems in insertion of distal interlocking screws occurred in 9 screws in group I and 11 screws in group II. The average number of images/exposures taken by image intensifier for nail insertion, for distal locking, and for the complete procedure in group I, were respectively 25.8, 24.2, and 50.08 compared with 24.8, 4.1 and 28.9, respectively in group II. All second distal (more proximal) holes were inserted successfully in group II. The statistically extremely significant decrease in radiation by 44% in the average total number of images required during the complete procedure was observed in nail over nail technique versus free hand technique.
Conclusion
This prospective study on distal locking of femoral intramedullary nails shows that radiation exposures to achieve equivalent precision are reduced with the nail over nail technique as compared with the free hand technique. It can also be used when an image intensifier is unavailable or goes out of order peroperatively. However, over reaming of 1.5mm is the key to the success of technique as it avoids nail deformation during insertion. Level of evidence: therapeutic level IV.
