Comparative Computer-Aided Analysis of Three-Dimensional Carpal Alignment in Scapholunate Advanced Collapse and Healthy Wrists.

Purpose: Scapholunate dissociation frequently results in malalignment and scapholunate advanced collapse (SLAC). Previous analyses have relied on visual observations of carpal angles among the scaphoid, lunate, and capitate on lateral radiographs. However, the 3-dimensional carpal alignment during SLAC progression remains unclear.

Comparison of computer-aided and manual measurements in the evaluation of carpal alignment.

The purpose of this study was to compare computer-aided analysis and different methods of manual measurements in the evaluation of carpal alignment. The radioscaphoid, radiolunate, radiocapitate and radiometacarpal angles were measured on cone-beam computed tomography (CT) scans of 30 healthy wrists by automated software (Disior Ltd.) and by hand surgeons using lateral radiographs reconstructed from the CT data.

Association of ulnar variance with three-dimensional carpal alignment and demographics in asymptomatic volunteers.

Background: Several carpal pathologies are considered to be related to ulnar variance. Recently, computer-aided computed tomography (CT) analysis software was introduced to quantify three-dimensional (3D) carpal alignment with high accuracy and reliability.

Purpose: To determine the association of ulnar variance with 3D carpal alignment and demographics.

Three-dimensional carpal alignment: computer-aided CT analysis of carpal axes and normal ranges.

Assessment of carpal alignment traditionally uses carpal bone axes measured on lateral radiographs. In this study, three-dimensional axes were defined for carpal bones using segmentation and numerical modelling of CT data of 121 neutrally positioned, asymptomatic wrists. The geometric axis was used for radius, scaphoid and capitate, whereas the axis based on a line perpendicular to the articular surface was used for the other carpal bones.

Computer-based three-dimensional measurement of carpal alignment: measurement techniques and normal ranges.

The three-dimensional carpal alignment was measured in the neutral wrist position in 121 asymptomatic volunteers using computer-based cone-beam CT analysis. Normal values and the reliability of the automated analysis are reported. An analysis software based on segmentation of CT images and mathematical modelling was used to determine several axis variants based on different landmarks and to calculate the intercarpal angles automatically.

Radiographic measurements of the normal distal radius: reliability of computer-aided CT versus physicians' radiograph interpretation.

We examined the reliability of a computer-aided cone-beam CT analysis of radiographic parameters of 50 normal distal radii and compared it with interobserver agreement of measurements made by three groups of physicians on two-dimensional plain radiographs. The intra-rater reliability of the computer-aided analysis was evaluated on 33 wrists imaged twice by cone-beam CT. The longitudinal axis, anterior tilt, radial inclination and ulnar variance were measured.