The inter-sternohyoid median (ISM) approach: a novel median anterior corridor to the cervical spine - anatomical study and preliminary clinical application.

PURPOSE: To describe the inter-sternohyoid median (ISM) anterior cervical spine approach and report anatomical validation and early clinical outcomes with a matched historical comparator.

METHODS

We performed anatomical and radiological studies to define the novel ISM surgical corridor. Subsequently, we retrospectively reviewed 25 cases operated with the ISM approach for cervical spine surgery. A matched historical cohort of 75 patients treated with standard anterolateral approaches was included (1:3 matching by sex, age ± 3 years, and number of operated levels). Outcomes included operative time, postoperative length of stay, Numeric Pain Rating Scale (NPRS), modified Rankin Scale (mRS), 1-month dysphagia (Dysphagia Outcome and Severity Scale [DOSS] ≤ 6), complication rate, and recurrence.

RESULTS

Anatomical and radiological assessment confirmed that the ISM corridor can provide access to selected subaxial levels. In the preliminary clinical application, corridor creation required 7-10 min. No complications were registered in either group at 30-day follow-up. Dysphagia at 1 month showed an absolute risk difference of - 8.0% (95% CI - 14.7 to - 2.7), a hypothesis-generating finding in this exploratory matched historical comparison. Matched-set mean differences (ISM-controls) were small for operative time (- 0.29 min), length of stay (- 0.76 days), NPRS at 1 month (- 0.47 points), and mRS at 1 month (- 0.14 points).

CONCLUSION

In selected patients, the ISM approach provides a short, medial, relatively orthogonal corridor to the subaxial cervical spine with feasible exposure and encouraging preliminary feasibility findings. The present exploratory analysis does not establish clinical superiority; prospective studies with larger comparative cohorts, objective anatomical measurements, and longer follow-up are warranted.