The application of a radiographically determined ratio as a new technique to identify the optimal level of transverse skin incision for anterior cervical spine surgery.

A transverse skin incision for anterior cervical spine surgery gives an excellent cosmetic result but is not extensile, thus accuracy of incision placement is essential. We describe a new, fast and inexpensive method of accurate transverse skin incision placement that does not rely on anatomical landmarks or intraoperative fluoroscopy. A ratio, determined by measurements from a lateral cervical spine radiograph, was applied to measurements on the patients' neck to determine the site for incision. The use of a ratio was designed to remove any inaccuracies related to X-ray magnification differences. A retrospective review of 54 consecutive anterior cervical spine procedures undertaken with this technique was performed. The operative level ranged from C2-C3 to C7-T1, the most common being C5-C6. Post-operative radiographic measurement of the incision site (marked by skin clips) demonstrated a mean distance of 5 mm (range 1-8 mm) from the centre of the skin clips to the predetermined ideal midpoint for each individual. In no case was it necessary to radically extend or to make a separate incision. The technique described is an accurate method of determining the level of transverse skin incision placement for cervical spine surgery that reduces intra-operative fluoroscopy time, radiation dose and expense.