Posterior occupancy ratio–guided anterior cervical discectomy and fusion combined with unilateral biportal endoscopic decompression for pincer-type cervical spondylotic myelopathy: a case report and literature review

Pincer-type cervical spondylotic myelopathy (CSM) represents a severe clinical phenotype characterized by simultaneous spinal cord compression from both ventral and dorsal structures, frequently necessitating circumferential decompression. Although traditional single-stage combined anterior-posterior (A-P) open surgery provides adequate decompression, it is often associated with extensive surgical trauma and an elevated risk of perioperative complications. A focused literature review was conducted in PubMed, Embase, and Web of Science (inception to December 31, 2025) using keywords related to ‘pincer-type cervical spondylotic myelopathy’, ‘circumferential decompression’, ‘anterior cervical discectomy and fusion’, and ‘biportal endoscopy’. Eligible publications included case reports/series and clinical studies describing surgical strategies for combined ventral and dorsal cervical cord compression; the identified literature generally supports the feasibility of minimally invasive anterior–posterior hybrid approaches as reported here. A 75-year-old male presented with a 10-year history of neck pain and acute progressive numbness and weakness of the left upper extremity over 10 days, with MRI demonstrating ventral disc herniations at C3–C4 and C4–C5 and concomitant dorsal ligamentum flavum hypertrophy (LFH) at C3–C4. To quantitatively evaluate the dorsal contribution to stenosis, the Posterior Occupancy Ratio (POR) was measured on axial T2-weighted images at the most stenotic level using the formula: POR = a/b×100%, where a denotes the maximal protrusion distance of the ligamentum flavum and b represents the bony sagittal diameter at the same level. The POR at C3/4 was 48%, supporting the need for concomitant posterior decompression. The patient subsequently underwent a single-stage hybrid procedure consisting of ACDF (C3-C4 and C4-C5) and posterior UBE decompression at C3-C4.The total operative time was 185 min, with an estimated blood loss of approximately 50 mL. Postoperative symptomatic relief was significant; at the 3-month follow-up, the Japanese Orthopaedic Association (JOA) score had improved from 11 to 16. No complications, such as cerebrospinal fluid leak, surgical site infection, or C5 palsy, were reported. Follow-up MRI demonstrated complete resolution of the circumferential compression at C3-C4 and significant restoration of spinal cord morphology. Quantitative metrics such as the Posterior Occupancy Ratio (POR) may assist preoperative planning by highlighting substantial posterior contribution to stenosis; a single-stage ACDF combined with posterior UBE appears to be a feasible, minimally invasive option in selected pincer-type CSM cases, but the proposed POR threshold and decision framework remain provisional and require prospective validation.