Ortho-Preferred

Myelomeningocele Scoliosis



- 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


Efficacy of surgical management for scoliosis in myelomeningocele: correction of deformity and alteration of functional status.

The crank shaft phenomenon.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, April 25, 2012 11:58 am