A New Trend in Cobb Angle Measurement: The Use of iPhones

The Cobb angle is a radiographic measurement for spinal deformities. The measurement is investigated both for the manual method of plain films and the computer-aided measurement of digitized films. We compared a manual method using a pencil and protractor with a computerized method using an iPhone for measuring standing radiographs in adolescent idiopathic scoliosis. There were no statistically significant differences between the two methods according to the mean Cobb angles (p > 0.05). The mean time consumed for the iPhone set was significantly shorter than that for the manual set (p < 0.05). The iPhone-aided measurement for the Cobb angle showed good reliability and efficiency. We conclude that the iPhone is a clinically good alternative measuring tool to the traditional protractor.