ANALYSIS OF THREE TYPES OF FIXATION OF THE WEIL OSTEOTOMY

 

Journal of Foot and Ankle Surgery

in revision

 

Craig T. Jex, D.P.M., St. John North Shores Hospital,

 26755 Ballard Road, Harrison,Township, MI 48045

 

Steve Rundell, B.S.,College of Engineering, Michigan State University,

A414-C East Fee Hall, East Lansing, MI 48824-1316

 

Chanda J. Wan, D.P.M, St. John North Shores Hospital, 26755 Ballard Road,

Harrison, Township, MI 48045, (586) 466-5379, Fax: (586) 465-7217, Chanda.wan@stjohn.org

 

Brian MacDonald, D.P.M., F.A.C.F.A.S., St. John North Shores Hospital,

26755 Ballard Road, Harrison Township, MI 48045

 

Roger C. Haut, Ph.D., College of Osteopathic Medicine, College of Engineering,

 Michigan State University, A414-E East Fee Hall, East Lansing, MI 48824-1316

 

ABSTRACT:

The Weil osteotomy is a popular method for the treatment of lesser metatarsalgia.  A variety of fixation methods exist for lesser metatarsal osteotomies.  This study assessed three methods of fixation for the Weil osteotomy.  Forty sawbone models were divided equally into four groups: a control and Weil osteotomies that were fixated with either two crossed Kirschner wires (0.045” k-wires), or Synthes[1] noncannulated 2.0mm cortical screws, and or Osteomed[2] cannulated 2.4mm cortical screws.  The control group consisted of intact lesser ray sawbones.  Each specimen was then stressed through a computer-controlled hydraulic tensile testing machine while recording maximum load, energy, and stiffness.  The mean load to failure of the groups was control, 62.9N; k-wire, 22.9N; cannulated screw, 31.3N; noncannulated screw, 19.9N.  There was no statistical difference between the three groups of fixation methods in terms of the maximum load supported.  The mean energy to failure of the control was 326J; K-wire, 79J; cannulated screw, 163J; noncannulated screw, 66J.  The cannulated screw allowed for a statistically greater amount of energy to reach failure than the noncannulated screw (p<0.05).  The mean structural stiffness of the control was 7.3 N/mm; k-wire, 2.8N/mm; cannulated screw 3.3 N/mm; noncannulated screw, 3.2N/mm.  There was no statistical difference between the three groups of fixation methods in terms of structural stiffness.The current results indicated that there was a trend towards better biomechanical stability with the 2.4mm cannulated screw than the 2.0mm noncannulated screw for the fixation of the Weil osteotomy in the clinical setting.



[1] Synthes Paoli, PA 19301

[2] Osteomed Addison, TX 75001

Orthopaedic Biomechanics Laboratories,

 College of Osteopathic Medicine,

 Michigan State University,

 East Lansing, Michigan 48824

 

Please address correspondence to:

 

Roger C. Haut, Ph.D.,

 Orthopaedic Biomechanics Laboratory,

 College of Osteopathic Medicine,

 A414 East Fee Hall,

 Michigan State University,

 East Lansing, MI 48824,

Tel:  (517)355-0320,

 Fax:  (517)353-0789,

  E-mail:  haut@msu.edu