Jnl Wrist Surg 2016; 05(01): 047-051
DOI: 10.1055/s-0035-1570396
Scientific Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Effect of Scaphoid Fracture Site on Scaphoid Instability Patterns

Frederick W. Werner
1  Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York
,
Hugo St-Amand
2  Division of Plastic and Reconstructive Surgery, Centre de Santé et de Services Sociaux de Gatineau, Gatineau, Quebec, Canada
,
Hisao Moritomo
3  Department of Physical Therapy, Osaka Yukioka College of Health Science, Osaka, Japan
,
Levi G. Sutton
1  Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York
,
Walter H. Short
1  Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York
› Author Affiliations
Further Information

Publication History

13 October 2015

23 November 2015

Publication Date:
31 December 2015 (online)

Abstract

Background Scaphoid fractures are common carpal fractures that are often misdiagnosed as wrist sprains and may go on to nonunion. The location of the fracture site may influence the stability of scaphoid nonunions.

Purpose To determine whether the stability of a scaphoid nonunion depends upon the fracture's location, we tested the hypothesis that a simulated fracture distal to the apex of the scaphoid dorsal ridge will have greater interfragmentary motion than proximal.

Methods Eleven cadaver wrists were moved through three wrist motions using a wrist simulator. In six wrists, a fracture was created distal to the scaphoid apex, and in five a fracture was created proximal to the apex. Sensors attached to the distal and proximal parts of each scaphoid measured the interfragmentary motion during wrist motion.

Results In those wrists in which the scaphoid was sectioned distal to the apex, the distal fragment became significantly more unstable relative to the proximal fragment. It flexed, ulnarly deviated, and pronated. These motion changes were less when the scaphoid was sectioned proximally.

Discussion Scaphoid fractures distal to the scaphoid apex will have greater interfragmentary motion. The mobility of the fragments at the fracture site is possibly a more important contributory factor of nonunion in scaphoid waist fractures than for proximal scaphoid fractures.

Clinical Relevance Understanding the effect that the location of a scaphoid fracture has on the potential for nonunion may influence the modalities of treatment and follow-up.

Note

Work was performed at SUNY Upstate Medical University.