- Discussion of Myelodysplasia
- Spinal Deformities:
-
vertebral column development:
- scoliotic & kyphosis in myelomeningocele may be either
congenital or
paralytic, or combination of both;
-
scoliosis in myelomenigocele:
-
kyphosis in myelomenigocele:
- need to distinguish between 2 distinct types of kyphosis both of which are centered over mid lumbar segment;
- C shaped curve w/o rigid segment;
- more progressive S shape curve w/ rigid kyphosis which often has
vertebral anomalies;
- pts less than 1 yr of age w/ a curve less than 90 deg can be expected to progress 8 deg / yr;
- pts older than 1 yr w/ curves greater than 90 deg may progress 13 deg / yr;
- radiographs:
- need to measure cobb angle on lateral radiographs;
- need to measure distance of kyphosis from line connecting C1 to S1;
- indications for treatment: (resection of kyphotic segment);
- increasing spinal deformity;
- respiratory deformity or crowding of abdominal contents;
- failure of skin ulcerations to heal;
- treatment:
- surgery should be delayed as long as possible inorder to delay recurrence;
- patent shunt is essential to prevent acute hydrocephalus, which can result from spinal sac excision usually necessary with kyphectomy;
- resection of kyphosis w/ local fusion or fusion to pelvis may be required;
- kyphectomy for severe
congenital kyphosis in pts with thoracic-level myelomeningocele is indicated for sitting imbalance or w/ skin problems occur over the apex;
- cordotomy:
- in the report by F Lalonde and J. Jarvis (JBJS 1999), the authors performed a cordotomy as a part of spinal correction in myelomeningocele patients
at an avg age of 9 years;
- cordotomy was performed at or below the level of the kyphosis;
- the mean kyphotic angle improved from 117 deg to 49 deg;
- only one patient showed deterioration of bladder function, whereas 8 out 9 patients showed improvement in bladder capacity and compliance;
- references:
-
Kyphotic deformity in patients who have a myelomeningocele. Operative treatment and long-term follow-up.
- Congenital kyphosis in myelomeningocele. The effect of cordotomy on bladder function.
F. Lalonde and J. Jarvis. JBJS. Vol 81-B. 1999. p 245-249.
- Upper Extremity:
- pt w/ incr upper extremity weakness should be evaluated for arrested hydrocephalus due to an Arnold Chiari malformation;
- Lower Extremity:
-
functional prognosis:
- quadriceps strength is the most important determinant of ambulation in adulthood;
- significant quadriceps weakness indicates a high lumbar neurologic level, and the prognosis for long term ambulation is poor;
- in children and adolescents, sacral and L5 lesions are consistent w/ community ambulation;
- where as the vast majority of children will be community ambulators, upto one third of adults will have a significant decline in their ability
to walk by adulthood (relying instead on wheel chairs);
- even w/ sacral level myelomenigocele long term functional results in adults is not promising;
- adults will commonly experience progressive motor and sensory loss in the foot and ankle (leading to reclassification of low lumbar level dysplasia);
- references:
- Ambulation in patients with myelomeningocele: A multivariate statistical analysis. Samuelsson L, Skoog M: J Pediatr Orthop 1988;8:569-575.
-
Myelomeningocele at the sacral level. Long-term outcomes in adults.
- Walking ability after transplantation of the iliopsoas: A long term follow-up. SA, Menelaus MB: J Bone Joint Surg 1984;66B:656.
-
hip in myelomeningocele:
-
fractures:
- frx are common in myelodydysplasia, most often about knee & hip in 3-7 yo age group, & are dx'ed by redness, warmth, and swelling;
- fractures usually heal with abundant callus;
- references:
-
Fractures in patients who have myelomeningocele.
TR Lock and DD Aronson. JBJS Vol 71-A. 1989. p 1153-1157.
-
myelodysplastic knee:
- usually includes quadriceps weakness (usually treated with KAFO's);
- recurvatum (associatted with clubfeet and hip dislocation) is rarely problem & can be treated with early with serial casting and KAFO's;
- tenotomies (quadriceps lengthening) are sometimes required;
- valgus deformities are usually not a problem;
- sometimes, iliotibial band release or late osteotomies may be needed (if they interfere with sitting or if they lead to foot deformities or ulceration);
-
foot deformities in myelomeningocele:
-
congenital vertical talus:
-
club foot:
- ankle vaglus:
- resulting from disparity in fibular versus tibial growth;
- treated w/ tibial osteotomy or hemiephysiodesis (older pts) if fibula is shortened, or Achilles tendon tenodesis to the fibula (younger patients);
- hindfoot valgus:
- total contact AFO's may be used initially;
- triple arthrodesis should be avoided in most myelodysplastics & is used only for severe deformities with sensate feet;
-
calcaneovalgus deformity:
- talipes calcaneus:
- arises from unopposed pull of
tibialis anterior tendon, toe extensors or the peroneal tendons;
- treatment:
- non-operative treatment for talipes calcaneus is limited;
- always seek to determine exact muscle imbalance causing this deformity;
- w/ mild deformity, simple resection of the offending tendon will allow foot to be brought into satisfactory position;
- in phase transfer: involves transfer of peroneal tendons to the os calcis;
- out of phase transfer: transfer
tibialis anterior thru interosseous membrane to os calcis;
- operative intervention is delayed until child is 18 months old;
- after age of 6 years, the deformity is usually osseous, and a posterior displacement osteotomy of the calcaneus may be necessary;
- after age of 10 years,
triple arthrodesis may be done for severe deformity that is not controllable by bracing or an osteotomy;
- however, many surgeon's are adverse to performing a triple arthrodesis in insensate skin;
- references:
-
The results of tenodesis of the tendo achillis to the fibula for paralytic pes calcaneus.
-
Treatment of the calcaneocavus foot deformity.
Current Concepts Review. Orthopaedic Aspects of Myelomeningocele.
Effectiveness of muscle transfer in myelomeningocele hips measured by radiographic indices. Yngve DA, Lindseth RE: J Pediatr Orthop 1982;2:121.
Rotational deformities of the lower limb in myelomenigocele. LS Dias. JBJS. Vol 66-A. 1994. p 215.
Assessment and management of the lower extremity in myelodysplasia. NC Carroll. Orthop Clin North Am. Vol 18. 1987. p 709-724.
Reduction in Neural-Tube Defects after Folic Acid Fortification in Canada
