Anatomic features of the carpal scaphoid: validation of biometric measurements and symmetry with three-dimensional MR imaging.

Abstract

The goals of reconstructive surgery for scaphoid fracture nonunions include restoration of normal scaphoid length and shape by use of the contralateral scaphoid bone as a geometric model. A literature search revealed limited documentation of normal biometric measurements and no validation of scaphoid anatomic symmetry. A study was performed to provide normative data and evaluate the right-to-left symmetry of specific geometric measurements of the scaphoid. One hundred normal carpal scaphoid bones in 30 healthy subjects and 40 patients were examined with three-dimensional magnetic resonance (MR) imaging. Standardized oblique projections were reconstructed from each three-dimensional data set, and seven biometric measurements of each scaphoid were obtained. Normative data from the study group were obtained by means of analysis of all 100 scaphoids. Right-to-left symmetry was validated with the biometric measurements of both scaphoids in the healthy subjects. These data validate scaphoid symmetry and provide 95% confidence intervals for specific biometric measurements that are used for preoperative planning of surgical reconstruction of scaphoid nonunions.