Posterior Cervical Muscle-Preserving Interspinous Process Approach and Decompression: 2 Case Reports With Surgical Video Demonstration

We report 2 cases of cervical myelopathy treated using a posterior cervical muscle-preserving interspinous process approach with decompression. This technique allows effective central decompression while preserving the extensor musculature and the anchoring function of the spinous processes. The first case involved a 64-year-old woman with multilevel cervical stenosis and myelopathy who underwent decompression at C5–7. The second case involved a 70-year-old woman with C4–5 ossification of the yellow ligament and progressive left arm weakness who underwent single-level decompression. Notably, neither case exhibited significant foraminal stenosis. In both procedures, a small midline incision was made to expose the interspinous space, followed by retraction of the interspinalis cervicis using a blunt mini-Gelpi retractor and undercutting decompression performed with a Kerrison punch and a high-speed drill. No intraoperative complications were observed. Postoperatively, both patients demonstrated neurological and functional improvement, including increased modified Japanese Orthopaedic Association and 36-Item Short Form Health Survey scores, decreased visual analogue scale pain scores, and preserved cervical alignment without evidence of dynamic instability on flexion–extension radiographs. The accompanying surgical videos illustrate the operative steps in detail and highlight the advantages of this minimally invasive technique for both single-level and multilevel decompression.