Reliability of 2 Smartphone Applications for Cobb Angle Measurement in Scoliosis

BACKGROUND: As mobile technology has evolved, smartphone applications have been used for radiographic angle measurements in daily clinical practice. This study aimed to assess the reliability of 2 smartphone applications (iPinPoint and Cobbmeter) in measuring scoliosis Cobb angles compared with picture archiving and communication system (PACS) tools. METHODS: Anteroposterior whole spinal digital radiographs of 50 patients were retrospectively analyzed. Four observers measured Cobb angles of predetermined major structural curves using the tools in the PACS software and 2 smartphone applications. The inter- and intraobserver reliabilty were measured using intraclass correlation coefficients (ICC). RESULTS: Very good interobserver agreement was seen with PACS, iPinPoint, and Cobbmeter measurements (ICC, 0.991, 0.980, and 0.991, respectively). Intraobserver reliability of the 4 observers was also very good for all techniques (ICC > 0.9 for all observers). CONCLUSIONS: Both smartphone applications were reliable in measuring scoliosis Cobb angles, with reference to PACS tools. They may be useful when digital or manual mesurement tools are not available.