Is the vertebral expandable prosthetic titanium rib a surgical alternative in patients with spina bifida?

Nonambulatory children with myelodysplasia are most likely to develop spinal deformity. As the deformity progresses, the overall health of the patient deteriorates. Traditional management of the deformity with fusion results in a short trunk, crankshaft deformity, and spine and lung growth inhibition. One alternative that potentially minimizes these problems is the vertebral expandable prosthetic titanium rib (VEPTR).

We therefore asked whether the use of the VEPTR in immature nonambulating children with myelodysplasia with spinal deformity would (1) correct deformity; (2) allow growth; and (3) allow adequate respiratory function.

We identified 20 nonambulatory patients with myelodysplasia who were part of a multicenter Investigational Device Exemption study of 214 patients treated with the VEPTR system. Demographics, standard radiographic measurements, pulmonary function parameters, and complications in 16 patients were analyzed. Average age at first surgery was 48.6 months. The minimum followup was 25 months (mean, 59 months; range, 25-164 months).

The Cobb angle decreased postoperatively in nine patients, increased less than 10° in five patients, and increased less than 20° in two patients. The mean increase in thoracic spinal length (growth) by year after the initial procedure with lengthening was 0.48 cm. Ventilatory function improved in 11 patients and deteriorated in five patients. Intraoperative complications occurred in two patients. Complications directly related to the implant were seven infections and five implant migrations.

Our observations suggest VEPTR is a reasonable treatment option for spinal deformity in the immature, nonambulatory myelodysplasia population correcting the spinal deformity, allowing spinal growth, and maintaining adequate respiratory function. The rate of complications is within the range reported for spinal fusion using standard approaches.