Should Children with Myelomeningocele and Scoliosis Undergo Spinal Surgery?

In children with myelomeningocele, scoliosis is a common and complicated problem. Most of the published literature on this topic addresses the technical correction of spinal deformities. Perhaps more important, however, are the functional consequences of such a serious surgery in this patient population.

Studies have clearly shown the ability to achieve significant reduction of the scoliotic curvature with surgical treatment in patients with myelomeningocele.^1–3 Progressive, untreated scoliosis often results in loss of truncal stability, which may endanger sitting balance. Thus, the main goals of surgical intervention should be prevention of progressive spinal deformity and improvement of sitting balance.^1,4

It is important to note that a corresponding improvement in ambulation, motor skills, and activities of daily living (ADL) has not been demonstrated in the literature. In fact, studies evaluating ambulatory ability after spinal fusion have suggested ambulation may be more difficult after surgery.^{1,2, 4} Multiple studies have also shown no significant difference in the ability to perform ADL after surgical intervention.^{1,2, 4}

Evidence

One study by Schoenmakers and colleagues¹ assessed 10 children with myelomeningocele who underwent spinal surgery. They found that ambulation became more difficult for three of the four patients who had been able to ambulate before surgery. They also note no long-term effects on ability to perform ADL after surgery (Level IV).

Another study by Müller and coworkers² examined the influence of surgical treatment for scoliosis on both ambulation and motor skills. This study included 14 patients from different levels of dysraphism. They found that in the eight patients with preoperative hip flexion contractures, averaging 15.2 degrees, there was a significant increase after surgery to 38.4 degrees. No patients experienced improvement in hip flexion contracture after surgery. In addition, seven patients lost the ability to ambulate with or without assistive devices after surgery. These authors did note three patients who gained better sitting balance. They also found no significant difference in the ability to manage ADL from before to after surgery. Of note, the authors found no significant difference in the postoperative changes with regard to motor skills, ambulation, and ADL between the different levels of dysraphism (Level IV).

A study by Mazur and researchers⁴ examined the effect of spinal fusion on sitting balance and ambulatory ability in 49 patients. They grouped results according to whether patients underwent staged anterior and posterior fusion, posterior fusion alone, or anterior fusion alone. They found improved sitting balance in 70% of patients after anterior and posterior fusions, 67% after posterior only, and 28% after anterior only. The authors also report an adverse effect on ambulation in 67% of patients with combined fusions, 27% of posterior-only fusions, and 57% of anterior-only fusions. No patients in this study showed improvement in ambulatory status after surgery. The authors also note little change in ability to perform ADL after surgery (Level III).

In a study by Wai and investigators,³ 80 children with myelomeningocele were assessed to determine the relation of spinal deformity to physical function and self-perception. They found no significant relation between spinal deformity and overall physical function or self-perception. The only aspect of spinal deformity that showed an effect on one aspect of physical function was coronal imbalance on sitting. The authors conclude that simple interventions such as chair modifications should be explored as a means to improve coronal balance and sitting function (Level IV).

It is important to keep in mind that the presence of infrapelvic pelvic obliquity can also contribute to the overall imbalance seen in patients with myelomeningocele with scoliosis. As an example, this could result from the combination of a unilateral hip adduction contracture with a contralateral hip abduction contracture. Patients should be assessed for infrapelvic obliquity, and if present, this should be addressed at the same time as correction of any spinal deformity.

In Children Who Undergo Surgery, Should Fusion Extend to the Sacrum?

In patients with spinal deformity and pelvic obliquity, the procedure of choice typically involves combined anterior and posterior surgery with fusion extending to the sacrum to achieve better curve correction and a lower pseudoarthrosis rate.⁵ Indications for extension of fusion to the sacrum include progressive scoliosis with lumbar spine involvement, neuromuscular scoliosis, pelvic obliquity greater than 15 degrees, poor sitting balance, and posterior lumbar and sacral dysraphism.⁶

Including the sacrum in fusion results in better correction of pelvic obliquity and improves sitting balance. However, it is important to note that fusion of the spine to the pelvis creates a rigid trunk, making walking more difficult.⁴ This is especially true in patients with myelomeningocele accustomed to ambulating with a swinging gait. In addition, extension of fusion to the sacrum with the resulting loss of lumbosacral mobility can adversely affect ability to perform wheelchair transfer.⁷ Another potential complication associated with fusion to the sacrum is the development of ischial pressure sores. Various studies have reported on this complication with a frequency varying from 3%⁵ to 33%.⁸

Wild and coworkers⁷