Modulation of Spinal Deformities in Patients With Neurofibromatosis Type 1

Abstract

Spinal deformities in patients with neurofibromatosis 1 should be regarded as deformities in evolution. One should resist assigning these evolving deformities to either the dystrophic or nondystrophic end of the spectrum without considering the possibility of modulation across the spectrum. A spinal deformity that develops before 7 years of age should be followed closely for evolving dystrophic features (i.e., modulation). When a curve acquires either three penciled ribs or a combination of three dystrophic features, clinical progression is almost a certainty.

Skeletal abnormalities in neurofibromatosis type 1: Approaches to therapeutic options

“…The term dystrophic has been utilized in the orthopedic literature to describe a dysplastic type of scoliosis with a rapid course of progression [Durrani et al, 2000]. Although no diagnostic criteria for dystrophic scoliosis exist, Durrani et al [2000] described nine specific radiographic features associated with dystrophic scoliosis (rib penciling, vertebral rotation, posterior vertebral scalloping, anterior vertebral wedging, lateral vertebral scalloping, vertebral wedging in either the sagittal or coronal plane, spindling of the transverse process, widened interpedicular distance, and enlarged intervertebral foramina). Non-dystrophic scoliosis is more common [Vitale et al, 2002] and resembles idiopathic adolescent scoliosis in the NF1-unaffected population.…”

Neurofibromatosis type 1 is a genetic skeletal disorder

“…One NF clinic reported that 38% of NF1 individuals had one or more orthopedic finding [Crawford and Schorry, 1999]. Skeletal manifestations of NF1 include long bone dysplasia with and without pseudarthrosis, sphenoid wing dysplasia, bone cysts, pectus deformities, relative macrocephaly, short stature for familial background, and dystrophic scoliosis with vertebral scalloping, vertebral wedging, spinal canal narrowing, vertebral body narrowing, and ribpenciling [Crawford and Bagamery, 1986;Schorry, 1999, 2006;Durrani et al, 2000;Vitale et al, 2002;Ramachandran et al, 2004;Tsirikos et al, 2004].…”

The Skeleton Abnormalities in Patients with Neurofibromatosis Type 1: Important Consequences of Abnormal Gene Function

“…Rotation of the ribs (the ribs resemble twisted ribbons) Table 3. The radiologic appearance of the dystrophic scoliosis (Durrani et al, 2000) Distinctive radiographic features of dystrophic scoliosis, usually presented in the preadolescent child, include a short-segment sharply angulated curve (involving four to six vertebrae), scalloping of vertebral margins, vertebral wedging, spinal canal widening, defective pedicles, and rib-penciling . It is potentially debilitating and may rapidly progress to neurological impairment.…”