Browsing by Author "Waris, Eero"

The purpose of this study was to assess the best way to measure carpal alignment. The study compared computer-based measurements and manual measurements of the carpal alignment. The subjects of comparison were the methods of measuring the radioscaphoid, radiolunate, radiocapitate and radiometacarpal angles. 30 cone beam CT scans of healthy, uninjured, wrists were analyzed by automated software (Disior ltd) and by hand surgeons using lateral radiographs reconstructed from the CT scans. Six hand surgeons were given instructions on how to take the measurements. They analyzed both reconstructed radiographs in which the wrist bones were partially overlapping due to summation, and reconstructed radiographs, where overlapping of the wrist bones had been digitally removed. In addition, seven different hand surgeons were not given instructions on the measurement methods. They analyzed only the reconstructed radiographs with wrist bones overlapping. In manual measurements, the inter- and intra-observer reliability of the results varied from good to excellent (ICC: 0.77–0.99), both in the instructed and in the uninstructed group. Inter-observer reliability was better in the group instructed in the methods of measurement. Reliability was further improved in reconstructed radiographs where the overlapping of the carpal bones had been digitally removed. Intra-observer reliability was very similar in both the instructed and uninstructed groups, and improved when bony overlapping was removed. The software provided excellent intra-observer reliability (ICC 0.94-1.00) and result, that were highly comparable the instructed manual measurements from radiographs with no bony overlapping (mean difference range 1°-7°). Although statistically significant differences were seen between manual measurements and software measurements, the differences are too small to be clinically significant. The research shows that accurate and repeatable computer-aided measurements of the carpal alignment can be made from CT scans, thereby minimizing observational errors. Key words: Carpal alignment, measurement, reliability, computer-aided, digitally reconstructed radiographs