Answer to the Letter to the Editor of V. Kumar et al. concerning "Can standard anterior Smith–Robinson supramanubrial approach be utilized for approach down to T2 or T3?" by Singhatanadgige W, Zebala LP, Luksanapruksa P, Riew KD [Eur Spine J (2017) 26:2357–2362]

[摘要] We would like to thank the reader for taking interest in our manuscript [Singhatanadgige W, Zebala LP, Luksanapruksa P, Daniel Riew K (2016) Can standard anterior Smith–Robinson supramanubrial approach be utilized for approach down to T2 or T3? Eur Spine J. doi: https://doi.org/10.1007/ s00586-016-4631-0]. In this study, we evaluated a plain radiographic criterion for determining the feasibility of using the standard anterior Smith–Robinson supramanubrial approach for anterior surgery down to T2 or T3. If a line from the intended skin incision to the lower instrumented vertebrae (LIV) passes over the top of the manubrium, a standard Smith–Robinson approach without sternotomy was successfully used for all 44 patients in our study. Visualization to cervico-thoracic junction and upper thoracic vertebrae is difcult with plain radiographs. However, by adjusting the exposure using digital radiographs, we were able to visualize the cervico-thoracic junction and upper thoracic vertebrae in most cases. We adjusted the exposure back and forth while identifying the LIV by starting from a clearly visualized lower cervical vertebra. We did not attempt to visualize the CTJ using traction or swimmer’s views [Toksoy A, Bektas F, Eken C, Ceken K, Cete Y (2010) Value of the swimming position and arm traction in visualizing the cervicothoracic junction over the standard lateral cervical X-ray. Int J Emerg Med 3:85–90. doi: https://doi.org/10.1007/s1224 5-010-0159-y; Davis JW (1989) Cervical injuries—perils of the swimmer’s view: case report. J Trauma 29:891–893], as our criterion does not require the clear visualization of the vertebra. Even though it may not be perfectly clear on radiographs, our criteria should work, as long as one can draw the line [Cho W, Buchowski JM, Park Y, Maeda T, Nabb CE, Riew KD (2012) Surgical approach to the cervicothoracic junction: Can a standard Smith–Robinson approach be utilized? J Spinal Disord Tech 25:264–267. doi: https://doi. org/10.1097/BSD.0b013e31821c2d60].