Prevalence of Osteochondromas in the Spine in Patients with Multiple Hereditary Exostoses

Multiple hereditary exostoses (MHE) is an autosomal-dominant disorder characterized by the development of multiple cartilage-capped exostoses originating from the physis that are known as osteochondromas. The potential for these osteochondromas to impinge on the spinal cord is a clinical concern. The aim of our study was to determine the prevalence of osteochondromas in the spine in individuals with MHE. Additionally, we aimed to identify any risk factors for neural-impinging osteochondromas.

We prospectively enrolled a cohort of patients and their family members with MHE at a single institution from 2010 to 2022. Demographics, osteochondroma location, and clinical outcomes were documented. Magnetic resonance imaging (MRI) scans were made and interpreted by a pediatric musculoskeletal radiologist. Patients were categorized based on osteochondroma location: no spinal involvement, on the spinal column, in the spinal canal but not impinging, or neural-impinging. We also noted when osteochondromas were present on the ribs and pelvis to assess if these were predictive of spinal involvement.

Ninety-four patients with MHE (50% female; 78% White; mean age, 23 years) were enrolled. Fifty (53%) had no spinal involvement. Twenty-two (23%) had osteochondromas located on the spinal column, 18 (19%) had osteochondromas in the spinal canal, and 4 (4%) had an osteochondroma causing neural impingement. Of the 4 with neural impingement, 2 displayed paraparesis requiring immediate surgical intervention. The remaining 2 patients were observed clinically and monitored with use of serial MRI scans. One patient developed symptoms and underwent surgical excision of the osteochondroma. The remaining patient remained stable throughout the follow-up period. Age, gender, and the presence of osteochondromas on the ribs and pelvis were not associated with spinal involvement, osteochondromas in the canal, or neural impingement.

Although nearly half of the patients had spinal osteochondromas, neural impingement was rare (4%). Neither age, gender, nor the presence of rib and pelvic osteochondromas were associated with spinal involvement, osteochondromas in the canal, or neural impingement. This information can be used to guide clinical decision-making regarding the use of MRI scans for patient screening.

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.