Surgical decompression versus structured conservative management for mild degenerative cervical myelopathy: A systematic review of functional outcomes and disease progression

Objective: To conduct a comparative systematic review following the PRISMA 2020 guidelines to evaluate short term (6 to 24 months) and long term (3 to 10 years) functional outcomes, neurological progression rates, cervical biomechanical parameters, and treatment related complications between surgical decompression and structured conservative management in patients with mild degenerative cervical myelopathy (defined by a modified Japanese Orthopaedic Association [mJOA] score of 15 to 17 or Nurick grade 0 to 1). Methods: A systematic literature search of open access peer reviewed studies published in English from January 2011 through October 2026 was performed across PubMed/MEDLINE, Google Scholar, and LILACS. Surgical technique descriptions, standalone case reports, noncomparative case series, narrative literature reviews, other systematic reviews, editorials, letters, technical notes, and any articles with retractions or errata were strictly excluded. Thirty-five original clinical studies comprising randomized controlled trials, prospective multicenter cohorts, propensity score matched cohorts, and national spine registries were included. Two independent reviewers performed study selection, data extraction, and quality assessment using the Cochrane Risk of Bias 2 (RoB 2) tool and the Newcastle Ottawa Scale (NOS). Results: Across 35 included studies encompassing 8,142 patients, surgical decompression in mild degenerative cervical myelopathy produced statistically and clinically significant improvements in mJOA score (mean gain of +0.9 to +1.6 points versus -0.5 to +0.1 points in conservative care, p < 0.001), Neck Disability Index (mean reduction of 9.5 to 12.4 points versus 1.4 points in conservative care, p < 0.001), and Short Form 36 Physical Component Summary (+5.7 to +6.8 points, p < 0.001) at 1 to 2 years. Under structured conservative management, 25.0 percent to 43.6 percent of mild patients experienced clinically meaningful neurological deterioration (≥1 point mJOA decline) within 2.5 to 5 years, leading to surgical crossover in 24.0 percent to 35.6 percent of cases. Biomechanical predictors of nonoperative failure included segmental angular hypermobility exceeding 11 degrees, dynamic spondylolisthesis exceeding 2 mm, cervical kyphosis, spinal cord compression ratio below 0.40, and T2 weighted intramedullary hyperintensity. In stable mild patients lacking dynamic instability, randomized 10 year follow up showed no significant functional difference between conservative and surgical arms. Surgical complication rates in mild cohorts ranged from 11.2 percent to 18.9 percent, predominantly transient dysphagia and superficial wound events. Conclusion: Early surgical decompression provides superior short term and long term functional recovery, quality of life gains, and protection against irreversible neurological deterioration in mild degenerative cervical myelopathy associated with dynamic biomechanical instability, cervical kyphosis, or high grade cord compression. Structured conservative management with close clinical surveillance remains a safe initial option exclusively for stable mild disease without dynamic canal stenosis or intramedullary signal alterations.