Radiographic angles in hallux valgus: comparison between manual and computer-assisted measurements

Radiographic angles are used to assess the severity of hallux valgus deformity, in preoperative planning, assessing postoperative outcomes, and in comparing results between interventions. The manual method to measure these angles has been shown to be prone to errors and to be time consuming. Computer programs are now available to assist in angular measurements. This study was undertaken to compare the reliability and time taken between the 2 methods. A total of 30 radiographs were used from a population of patients with hallux valgus deformity. The radiographs were digitized for computer-assisted measurements. The technical error of measurement (TEM) was calculated for intra- and interobserver data to assess the error in angular measurement with both methods. The technical error of measurement was lower with the computer-assisted method, suggesting that this method is more reliable. Furthermore, the time taken was also reduced with this method.