Three-dimensional Spinal Canal Morphometric Analysis and Relevant Spinal Cord Occupational Ratios in Congenital Cervical Spinal Stenosis: A Classification Algorithm of the Stenosis Phenotypes and Data-driven Decompression Approach.

OBJECTIVES: No standardized magnetic resonance imaging (MRI) parameters have defined the 3-dimensional morphoanatomy and relevant spinal cord occupation ratios (occupation of spinal cord dimensions/similar dimensions within the spinal canal) in congenital cervical stenosis (CCS). METHODS: A retrospective, comparative analysis was conducted on 200 patients >18 years of age with myelopathy and CCS (mean age, 52.4 years) and 200 age-matched controls with no myelopathy or radiculopathy. The variables assessed from high resolution MRI included sagittal and axial spinal canal dimensions (MRI Torg-Pavlov ratios) from C3 to C7. Morphometric dimensions from the sagittal retrodiscal and retrovertebral regions as well as axial MRI dimensions were compared. Sagittal and axial spinal cord occupation ratios were defined and correlated with spinal canal dimensions. RESULTS: Multivariate analyses indicated reduced sagittal and axial anteroposterior (AP) spinal canal dimensions and a large reduction in transverse spinal canal dimensions at all spinal levels. There was a small significant correlation between AP sagittal spinal canal dimensions and axial transverse spinal canal dimensions at C3-C5, but not at C5-C6. Small correlations were noted between AP sagittal spinal canal dimensions and AP axial spinal cord and axial cross-sectional area occupation ratios at C3-C6, but there was no correlation with axial mediolateral spinal cord occupation ratios. CONCLUSIONS: The stenosis effect can involve any dimension, including the transverse spinal canal dimension, independent of other dimensions. Owing to the varied observed morphoanatomies, a classification algorithm that defines CCS specific phenotypes was formulated. Objectivizing the stenosis morphoanatomy may allow for data-driven patient-focused decompression approaches in the future.

The New England Neurosurgical Society: growth and evolution over 70 years.

The New England Neurosurgical Society (NENS) was founded in 1951 under the leadership of its first President (Dr. William Beecher Scoville) and Secretary-Treasurer (Dr. Henry Thomas Ballantine). The purpose of creating the NENS was to unite local neurosurgeons in the New England area; it was one of the first regional neurosurgical societies in America. Although regional neurosurgical societies are important supplements to national organizations, they have often been overshadowed in the available literature. Now in its 70th year, the NENS continues to serve as a platform to represent the needs of New England neurosurgeons, foster connections and networks with colleagues, and provide research and educational opportunities for trainees. Additionally, regional societies enable discussion of issues uniquely relevant to the region, improve referral patterns, and allow for easier attendance with geographic proximity. In this paper, the authors describe the history of the NENS and provide a roadmap for its future. The first section portrays the founders who led the first meetings and establishment of the NENS. The second section describes the early years of the NENS and profiles key leaders. The third section discusses subsequent neurosurgeons who steered the NENS and partnerships with other societies. In the fourth section, the modern era of the NENS and its current activities are highlighted.

Postlaminectomy lumbopelvic sagittal changes in patients with developmental lumbar spinal stenosis grouped into Roussouly lumbopelvic sagittal profiles: 2- to 10-year prospective follow-up.

OBJECTIVE: Roussouly lumbopelvic sagittal profiles are associated with distinct pathologies or distinct natural histories and prognoses. The associations between developmental lumbar spinal stenosis (DLSS) and native lumbopelvic sagittal profiles are unknown. Moreover, the relative effects of multilevel decompression on lumbar sagittal alignment, geometrical parameters of the pelvis, and compensatory mechanisms for each of the Roussouly subtypes are unknown. This study aimed to explore the association between DLSS and native lumbar lordosis (LL) subtypes. It also attempts to understand the natural history of postlaminectomy lumbopelvic sagittal changes and compensatory mechanisms for each of the Roussouly subtypes and to define the critical lumbar segment or specific lordosis arc that is recruited after relief of the stenosis effect. METHODS: A total of 418 patients with multilevel DLSS were grouped into various Roussouly subtypes, and lumbopelvic sagittal parameters were prospectively compared at follow-up intervals of preoperative to < 2 years, 2 to < 5 years, and 5 to ≥ 10 years after laminectomy. The variables analyzed included LL, upper lordosis arc from L1 to L4, lower lordosis arc from L4 to S1, and segmental lordosis from L1 to S1. Pelvic parameters included pelvic incidence, sacral slope, pelvic tilt, and pelvic incidence minus LL values. RESULTS: Of the 329 patients who were followed up throughout this study, 33.7% had Roussouly type 1 native lordosis, whereas the incidence rates of types 2, 3, and 4 were 33.4%, 21.9%, and 10.9%, respectively. LL was not reduced in any of the Roussouly subtypes after multilevel decompressions. Instead, LL increased by 4.5° (SD 11.9°-from 27.3° [SD 11.5°] to 31.8° [SD 9.8°]) in Roussouly type 1 and by 3.1° (SD 11.6°-from 41.3° [SD 9.5°] to 44.4° [SD = 9.7°]) in Roussouly type 2. The other Roussouly types showed no significant changes. Pelvic tilt decreased significantly-by 2.8°, whereas sacral slope increased significantly-by 2.9° in Roussouly type 1 and by 1.7° in Roussouly type 2. The critical lumbar segment that recruits LL differs between Roussouly subtypes. Increments and changes were sustained until the final follow-up. CONCLUSIONS: The study findings are important in predicting patient prognosis, LL evolution, and the need for prophylactic or corrective deformity surgery. Multilevel involvement in DLSS and the high prevalence of Roussouly types 1 and 2 suggest that spinal canal dimensions are closely linked to the developmental evolution of LL.