Determining spinal level using the inferior angle of the scapula as a reference landmark: a retrospective analysis of 50 radiographs.

OBJECTIVE The purpose of this study was to determine which spinal segment most closely corresponds to the level of the inferior angle of the scapula (IAS) using measurements taken on A-P full-spine radiographs. METHODS Fifty sequentially selected radiographs were analyzed independently by two examiners. A straight edge was used to ascertain which spinal levels corresponded with the right and left IASs. For analysis, each spinal level was subdivided into three regions: upper vertebral body, lower vertebral body, and intervertebral space. RESULTS he mean spinal level corresponding to the left IAS was midway between the T8-9 interspace and the upper T9 body (range, lower T7 to upper T10). The mean spinal level corresponding to the right IAS was slightly lower, but still within the upper T9 body (range, lower T7 to lower T10). These levels correspond to the T8 spinous process. CONCLUSIONS There is a considerable amount of variability in where the IASs are located, but most commonly, they correspond to the level of the upper body of T9.