Is Routine Spine MRI Necessary in Skeletally Immature Patients With MHE? Identifying Patients at Risk for Spinal Osteochondromas.

BACKGROUND: Multiple hereditary exostoses (MHE) is an autosomal dominant condition leading to development of osteochondromas throughout the body. Although long bones are most often affected, spine involvement may occur and usually requires advanced imaging for diagnosis. However, the high cost of detection, infrequent occurrence, and very low likelihood of spinal cord compression and neurological injury, create a management conundrum. The purpose of our investigation is to identify patients at greatest risk for spinal lesions and refine indications for advanced imaging.

METHODS: All MHE patients in a 24-year period were retrospectively reviewed. Skeletally immature patients with advanced imaging of the spine were further evaluated. The demographic characteristics, family history, clinical presentation, past surgical history, tumor burden, and distribution of patients with spinal lesions were compared with those without.

RESULTS: In total, 227 MHE patients were identified and 21 underwent advanced spinal imaging. Spinal lesions were found in 8 of the 21 screened patients (38.1%, 3.5% overall), of which 4 were intracanal and 1 was symptomatic (4.8%, 0.4% overall). Only the symptomatic patient underwent excision of the spinal lesion. Patients with spinal lesions had higher tumor burden than those without (median, 28.5 vs. 19 locations; P=0.010). There was a significant association with rib (P=0.018) and pelvic (P=0.007) lesions, which may serve as "harbinger" lesions. The presence of both a rib and a pelvic lesion used as a screening tool for spinal lesions produces a sensitivity of 100% and specificity of 69%.

CONCLUSIONS: Symptomatic spinal involvement in children with MHE is rare and tends to occur in patients with higher tumor burden. We recommend limiting advanced spine imaging to children with neurological symptoms or with rib and pelvic "harbinger" lesions. Patients without these findings are unlikely to have spine involvement needing intervention. This approach offers an opportunity to avoid unnecessary testing and substantially reduce costs of diagnostic imaging.

LEVEL OF EVIDENCE: Level III.