A Biomechanical Comparison of Intramedullary Nail and Crossed Lag Screw Fixation for Tibiotalocalcaneal Arthrodesis
Foot Ankle Int. 1997 Oct;18(10):639-643
Berend ME, Glisson RR, Nunley JA
BACKGROUND: This study compared the mechanical bending and torsional properties of intramedullary nail fixation and lag screw fixation for tibiotalocalcaneal arthrodesis.
METHODS: Seven matched pairs of human cadaver lower extremities were studied, with one hindfoot in each pair stabilized with a 12 mm x 150 mm interlocked intramedullary nail inserted retrograde across the subtalar and ankle joints. The contralateral hindfoot was stabilized with two crossed 6.5 mm cannulated screws inserted across both the ankle and subtalar joints. Specimens were subjected to cantilever bending tests in plantarflexion, dorsiflexion, inversion, and eversion and to torsional tests in internal and external rotation.
RESULTS: The intramedullary nail construct was significantly (P < 0.05) stiffer than the crossed lag screw construct in all four bending directions and both rotational directions: plantarflexion (nail, 42.8 N/mm; screws, 16.4 N/mm; P = 0.0003), dorsiflexion (nail, 43.0 N/mm; screws, 10.3 N/mm; P = 0.0005), inversion (nail, 37.7 N/mm; screws, 12.3 N/mm; P = 0.0024), eversion (nail, 35.4 N/mm; screws, 10.8 N/mm; P = 0.0004), internal rotation (nail, 1.29 N-m/degree; screws, 0.82 N-m/degree; P = 0.01), external rotation (nail, 1.35 N-m/degree; screws, 0.44 N-m/degree; P = 0.0001).
Copyright © 1997 (Foot Ankle Int. Oct;18(10):639-643) by the American Orthopaedic Foot and Ankle Society, Inc., originally published in Foot & Ankle International, and reproduced here with permission.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Tuesday, May 8, 2012 9:32 am