- See:
-
Orthopaedic Manifestations of Myelomeningocele:
- Discussion:
- scoliosis in myelomenigocele may have a multifactorial etiology:
- idiopathic causes;
- myelomeningocele structural defect;
-
congenital defects
- paralytic etiology;
- 15-20% of children who have myelomeningocele have congenital vertebral abnormalities in
addition to
congenital scoliosis;
- over-all incidence of scoliosis in pts who have thoracic-level lesion is 85%;
- all children who are born with an osseous dysraphism at level of T12 or higher, are at risk for
the development of a severe scoliotic deformity for which arthrodesis is needed;
- progression of scoliosis in myelomeningocele is natural;
-
progressive scoliosis in myelomeningocele:
- may manifest as lower extremity spasticity;
- MRI is helpful in evaluating these children;
-
diff dx:
-
tethered cord:
- if curve continues to progress despite neurosurgical release of tethered cord, then curve
must be stabilized with spinal fusion;
- non-functioning shunt:
- must be corrected before attempt is made to correct the scoliotic deformity;
- Arnold Chiari malformation:
-
syringomyelia:
- hydromyelia:
- hydrocephalus:
-
treatment considerations:
- goal is to have a compensated spine of normal height over level pelvis, w/ preservation of normal sagittal alignment;
- documented progression of curve is indication for early fusion, just as in child who does not have myelomeningocele;
- Bracing:
- orthotic treatment is helpful for the more common paralytic curve until the child reaches puberty;
- although
bracing does not alter natural history of deformity, it promotes spinal growth
& preserves better sitting posture, esp in pts who have lesion at thoracic level;
- carefully fitted, custommolded, bivalve plastic total-contact
thoracolumbosacral orthosis provides
maximum support and allows monitoring of the skin over pressure-sensitive areas;
- custom-molded chair insert for sitting is valuable for the child who has high thoracic-level
lesion or severe kyphotic deformity;
- attempts at bracing (TLSO) may fail & require subcutaneous rodding for very young children and fusion later;
- Operative Treatment of Scoliosis:
-
preop eval:
- aggressive evaluation of urinary tract, treatment of urinary tract infection, &
periop ATB are important in reducing wound infections;
- treatment of the scoliosis without recognition of syringomyelia and Chiari malformation can lead to paraplegia;
-
paralytic scoliosis:
- treated w/ anterior arthrodesis combined w/ posterior arthrodesis and secure internal fixation, plus bone grafting;
-
luque sublaminar wiring w/ fixation to
sacrum;
- curves > 60 deg require initial anterior release & fusion;
- Selection of fusion level;
- it is difficult to decide which levels to include in spinal fusion;
- 55-deg curve that ends at L-3 can probably be corrected satisfactorily w/ anterior/posterior
fusion & instrumentation so that sacral fusion will not be necessary;
-
fusion to sacrum:
- arthrodesis to pelvis is often needed to correct severe pelvic obliquity and dysraphism;
- in pts w/ high-level myelomeningocele, it is important to fuse to sacrum if
curve is major and cannot be corrected below 15 deg;
- in child w/ low lumbar myelomeningocele who is able to walk, a fusion
to sacrum will impair walking ability & confine child to wheelchair;
- sacrum should not be fused in walking child unless it is absolutely necessary;
-
high-level myelomeningocele:
- it is important to fuse to
sacrum if curve is major and cannot be corrected below 15 degrees;
-
low level myelomeningocele:
- in pt w/ low lumbar myelomeningocele who is able to walk, fusion to
sacrum will impair
walking ability & confine child to a wheelchair;
-
staged anterior & posterior arthrodesis:
- in young child, it is important to maintain anterior/posterior fusion, otherwise
crank shaft
phenomenon" may develop w/ continued progression of curve;
- staged anterior & posterior arthrodeses are necessary to achieve adequate correction and solid
fusion due to absence of posterior osseous elements, muscle weakness, & lack of ligamentous
support in the dysraphic spine,
- combined anterior & posterior arthrodeses allow for major correction of spinal deformity
as well as stabilization of
pulmonary function and improvement of respiration;
-
posterior arthrodesis:
-
Luque and
CD systems may allow isolated posterior arthrodesis w/o need for anterior fusion;
- Complications:
- spinal operations in patients who have
myelomeningocele have been associatted w/
high incidence of complications such as pseudarthrosis, loss of correction, & sepsis;
Surgical management for scoliosis in myelomeningocele:
Correction of deformity and alteration of functional status.
Mazur J, Menelaus MB, Dicksen DR, et al:
J Pediatr Orthop 1986;6:568.
The crank shaft phenomenon.
Dubousset J, Herring JA, Shufflebarger H:
J Pediatr Orthop 1989;9:542-550.
