Comparison of Preoperative Methods for Intramedullary Nail Length Measurement and Determination of the Best Method for Estimation in Femur and Tibia Fractures

Tibia and femur fractures are among the most common fractures and intramedullary nailing is the standarad treatment. This study was performed to determine the best preoperative method for estimating the intramedullary nail length.
In a cross sectional study, 82 patients with tibia and 25 patients with femur shaft fracture were studied in a training center of Kerman-Iran. The estimated preoperative intramedullary nail length and the length of used nail at operation were compared. The measurment methods for femur fractures were greatrer trochanter-patella, greater trochanter-lateral epicondyle and olecranon-fithe finegr tip; and for tibia fractures were medial malleolus-tuberosity, intact leg radiogram and olecranon fifth metacarp were assessed. Data was assesed by statistical methods.
Almost all of the examined methods showed "good" interobserver and intraobserver reliability. In femur fracture, the greater to patella method showed the best ICC (0.876) and the lowest SEM (0.777). In tibia fracture, best ICC (0.860) and the lowest SEM (0.602) were for medial malleolus tubercle method. For femur fractures, 64% of the measurements in greater to patella, 93% in olecranon fifth finger, 100% of greater to epicondyle methods; and for tibia fractures 40.9% in medial malleolus tubercle, 37.3% of olecranon metacarp and 65.06% of radiogram method were larger than the nail used at operation.
The best method for estimation of nial length was medial malleolus to tuberosity for tibia fractures, and greater to patella method for femur fractures; however none of the examined methods was found completely suitable.