The Infra-hyoid Median Approach: A Novel Surgical Corridor to the Anterior Subaxial Cervical Spine. Step-by-Step...

The classical anterior approach to the subaxial cervical spine, the Cloward and Smith-Robinson approach (SRA), has been the standard for decades, but it follows an oblique trajectory needing severe muscle retraction with potential postoperative morbidity. This study introduces a new infra-hyoid median approach (IHMA), which accesses the spine through a medial corridor between the omohyoid and sternohyoid muscles.

A total of 5 cadaveric specimens were dissected. A stepwise anatomic dissection was recorded and detailed, as well as a 3-dimensional photogrammetry model. Both the SRA and IHMA were performed on 3 specimens. Computed tomography scans were imported to ApproachViewer, a neuronavigation software, and used to quantify surgical volumes and exposure surfaces. During neuronavigation, the retraction forces applied on the medial soft tissues of the neck were measured with an analog manometer. Statistical analysis was conducted.

The SRA was divided into high-retraction (hrSRA) and minimum-retraction (mrSRA) depending on the forces applied medially to reach the midline. In both the non-crossing and crossing configuration, the IHMA offered a significantly wider exposure (153 ± 19.5 and 414.3 ± 76.4 mm2) compared with both hrSRA and mrSRA (hrSRA: 122.6 ± 31.5 and 345.4 ± 79.7 mm2; mrSRA: 95.5 ± 10.5 and 249.8 ± 46.6 mm2). The same evidence was found regarding working volumes (IHMA: 116.3 ± 23.7 and 617.3 ± 100 mm3; hrSRA: 79.2 ± 34.5 and 412.9 ± 95.3 mm3; mrSRA: 60.8 ± 12.1 and 308.8 ± 90.6 mm3). The IHMA and mrSRA required fewer, comparable retractions than hrSRA.

The study presents and validates a new approach to the anterior subaxial cervical spine. Compared with traditional SRA, the IHMA offers similar or better exposure while requiring much less tissue retraction. It provides wider working areas and greater exposure with minimal soft tissue and visceral manipulation, suggesting potential benefits in reducing postoperative complications.