Establishment of Parameters for Congenital Thoracic Stenosis: A Study of 700 Postmortem Specimens

Abstract

Background Congenital thoracic stenosis (CTS) occurs when the bony anatomy of the canal is smaller than expected in the general population. The diagnosis currently is made based on the clinical impression from subjective radiographic studies, and the normal values for CTS have not been established. Questions/purposes We provided a statistical definition for CTS based on objective measurements of thoracic spine specimens and explored parameters that might predict CTS. Methods We selected 700 adult skeletal specimens from the Hamann-Todd Collection in the Cleveland Museum of Natural History (Cleveland, OH, USA). We used calipers to measure the sagittal canal diameter (SCD), interpedicle distance (IPD), and pedicle length (PL). At each level, canal area was calculated using a geometric formula, a standard distribution was created, and values two SDs below the mean were considered congenitally stenotic. . A SCD less than 15 mm and an IPD less than 18.5 mm were predictive of CTS at each level with sensitivities and specificities of 80% to 100%. Conclusions We statistically defined CTS at each level. A SCD less than 15 mm or IPD less than 18.5 mm predicted the presence of CTS at all levels. Clinical Relevance In a symptomatic patient, on routine radiologic examination, a physician should suspect stenosis of the thoracic canal if the SCD and IPD are less than 15 and 18.5 mm respectively. As a spinal deformity surgeon, the canal area is especially relevant when considering a possible canal intrusion by implants.

Diffuse Spinal Hyperostosis Causing Severe Spinal Stenosis and Thoracic Myelopathy

“…Of these problems, OLF is the most reported causative factor, but a combination of these problems can also be responsible. 2,3,5,6 In this case series, we report a unique association among three cases of critical multilevel spinal stenosis caused by diffuse spinal hyperostosis in young patients with morbid obesity.…”

“…Only 1% of these cases are reported to occur in the thoracic region. 3 Thoracic spinal stenosis (TSS) may co-occur with cervical or lumbar stenosis. 4 TSS is most frequently due to ossification of the posterior longitudinal ligament (OPLL), ossification of the ligamentum flavum (OLF), posterior osteophytes, or thoracic disk herniation (TDH).…”