Comparison between manual and computer-assisted measurements of hallux valgus parameters

Background: The aim of this study was to determine if there are intraobserver and interobserver differences in reliability when measuring hallux valgus angles (HVA), 1-2 intermetatarsal angles (IMA), and distal metatarsal articular angles (DMAA) manually compared to computer-assisted means. Our hypothesis was that the measurements taken by computer-assisted methods of these three forefoot angles would be superior in consistency and accuracy compared to manual measurements. Methods: Four examiners studied 20 weightbearing anteroposterior radiographs of patients with hallux valgus. Manual measurements were taken on photographic prints using a goniometer and a fine point pen. Computer-assisted measurements were taken on digitized images using computer software. Three sets of measurements by both of these methods were taken 1 week apart. Results: There was no statistically significant difference between digital and manual measurements for any of the three angles measured (p.05). However, the reliability of measurements within a range of 5 degrees for both methods was 70.6% for HVA, 84% for 1-2 IMA, and 59% for DMAA. Conclusion: There were no significant differences in interobserver and intraobserver reliability in measuring 1-2 IMA and HVA, regardless of the method of measurement; however, there was a significant difference in interobserver reliability when measuring the DMAA either on computer or manually (p = < .05).