A prospective study of a new technique.Objective:
The aims of this study were to report a manual technique for measuring vertebral curves on digital spine radiographs, and to assess the agreement of this technique with that of digital software for measuring vertebral curves.Summary of Background Data:
Modern picture archiving and communication systems (PACS) typically include software for evaluating radiographic measurements. However, in the outpatient spine setting, patients may present with radiographs stored on a physical disc, which may not include software for measuring vertebral curves. Certain smartphone applications may be used to determine curve magnitude; however, the need exists for an accurate manual technique to measure vertebral curves on digital radiographs in the absence of available analytic software or smartphone technology.Methods:
We prospectively reviewed anteroposterior and lateral spine radiographs of 24 spinal deformity patients. Two independent observers measured Cobb angles for: (1) the major coronal curve; (2) the thoracic kyphosis (T2–T12); and (3) the lumbar lordosis (T12–S1). Measurements were made: (1) digitally using our institution’s PACS; and (2) by a manual technique, which involves placement of an adhesive Post-It note directly on the computer screen, transcribing the angle onto the Post-It note with a pencil, and measuring the angle with a handheld goniometer. Intraclass correlation coefficients (ICCs) were calculated to determine the agreement between the 2 methods.Results:
For both observers, the agreement between the digital PACS and manual Post-It techniques was graded as excellent for both coronal and sagittal plane curves (all ICCs>0.9). Interobserver reliability between the 2 observers was also graded as excellent for both the PACS and Post-It techniques (all ICCs>0.9).Conclusions:
The Post-It technique for measuring Cobb angles demonstrated excellent agreement with the PACS system in our series of spinal deformity patients. Curves on digital radiographs can be accurately measured using a convenient manual technique.