Epidemiology
2% scoliosis patients have NF
10 - 30 % NF patients have spinal deformity
- most common skeletal manifestation
- mostly non dystrophic variety
Types
A. Non dystrophic
- vertebral wedging, angulation and rotation
- very similar to idiopathic scoliosis
- right thoracic
B. Dystrophic
Cause
- may be due to intraspinal lesions such as tumours, meningoceles and dural ectasia
- can simply be bony dysplasia
Characterised by
- short segments, sharp angulation with severe apical rotation
- scalloping posterior margins
- widening of the spinal canal
- enlargement of neural foramina
- widened interpedicular distance
- thinned defective pedicles and lamina
- paraspinal mass
- rotation of ribs - 'pencilling'
Other problems
Cervical spine kyphosis
Atlantoaxial dislocation
- has been reported in five patients
- flexion and extension views are important in assessing cervical instability
- needed pre-op
Kyphosis
- marked acute posterior angulation
- can develop myelopathy and even paralysis
Intraspinal Tumours
Dural Ectasia
- circumferential dilatation of dural sac
- contains CSF and brown material
- erodes osseous structures
- very thin lamina
- can cause great angular deformity
- may have multiple dumbbell appearances
Dumbbell lesion
- single neurofibroma
Meningocoeles / pseudomeningocoeles
Management
Non Operative Management
Brace treatment
Not been effective in dysplastic curves
Can use early in non dysplastic
Operative Management
Non dystrophic
Issues
Recommend posterior fusion for progressive
- lower threshold for surgery than in idiopathic
- potential for progression much higher
Surgery as for idiopathic
Idiopathic
Brace 20 - 35o
Surgery > 35o
Dystrophic
Issues
A. All dystrophic curves need MRI to assess intraspinal lesion
B. All need C spine screening before surgery
- these patients also often have cervical spine abnormalities and instability
C. Incidence of pseudoarthroses ranges from 6% to 38% with isolated posterior fusion
- recomment addition of anterior fusion for dysplastic scoliosis is therefore recommended
- anterior release then posterior fusion
Indications
Anterior release and fusion followed by posterior fusion if > 50o
Kyphoscoliosis
Posterior fusion alone is usually insufficient in patients with kyphosis
Decompression of the cord with laminectomy
- contraindicated because the lesion is usually anterior
- removal of the posterior elements predisposes the patient to further postlaminectomy kyphosis.
- need decompression and fusion
> 50o
- brace early
- need anterior and posterior fusion
- may even need brace post surgery
- if have myelopathy symptoms may also need decompression
Lordoscoliosis
- in dystrophic