Femoral Head Lag Screw Position for Cephalomedullary Nails

• DOI: 10.1097/bot.0b013e318229acca
• Publication Date: 2012-02-15T09:44:11Z
• Authors: Paul R. T. Kuzyk; Rad Zdero; Suraj Shah; Michael Olsen; James P. Waddell; Emil H. Schemitsch
• Keywords: Calcar; Lag screw; Biomechanics

The purpose of this study was to determine if lag screw position affects the biomechanical properties a cephalomedullary nail used fix an unstable peritrochanteric fracture.Unstable fractures were created in 30 synthetic femurs and repaired with Long Gamma 3 Nails using one 5 positions: superior, inferior, anterior, posterior, or central. Radiographic measurements including tip-apex distance calcar referenced calculated from anteroposterior lateral radiographs. Specimens tested for axial, bending, torsional stiffness then loaded failure axial position. Analysis variance linear regression statistical analysis.The inferior had significantly greater mean than superior (P < 0.01), anterior = 0.02), posterior 0.04) positions. revealed less compared other positions 0.01 all 4 pairings). No differences noted bending stiffness. Superior central load-to-failure P 0.02) 0.05) There significant negative correlations between on radiographs center femoral neck radiographs.The produced highest Anterior lowest stiffnesses load-to-failure. Inferior placement radiograph is recommended.