Comparison of Bending Strength of Six Different Type of the First Metatarsal Osteotomies

Chu, In Tak; Chung, Yang Guk; Chang, Cheong Ho; Kang, Young Mok

Abstract

PURPOSE
We compare the sagittal stability of 6 different osteotomies of the metatarsal shaft : the proximal crescentic, proximal chevron, Mau, Scarf, Ludloff, and biplanar closing wedge osteotomies.
MATERIALS AND METHODS
Ten fresh frozen, human cadaveric specimens were used for each osteotomy. All specimens were then dissected out en bloc as the first metatarsal -medial cuneiform complex which was fixed with 3 Kirschner wires and clamped to a MTS Mini Bionix load frame. Cantiliver bending load was applied until bony fracture, pull out of screw, or a displacement of osteotomy greater than 2 mm as measured by the extensometer was observed. The data was compared with Student's t-test.
RESULTS
The average bending strength for 6 osteotomies were 199.56 kg/cm2 in proximal crescentic osteotomy, 205.3 kg/cm2 in proximal chevron osteotomy, 372.0 kg/cm2 in Ludloff osteotomy, 428.4 kg/cm2 in Scarf osteotomy, 508.8 kg/cm2 in biplanar closing osteotomy, and 530.0 kg/cm2 in Mau osteotomy. Statistical analysis revealed insignificant difference (P>0.01) between Ludloff and Scarf and biplanar closing wedge and Mau osteotomies. There were statistical differences between Mau or Scarf osteotomy and proximal chevron or crescentic osteotomy.
CONCLUSION
Proximal chevron and proximal crescentic osteotomies need longer postoperative immobilization for the prevention of plantar angulation of first metatasus.