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.