by Behrooz A Akbarnia, MD
When children develop curvatures at a very young age, they do not follow the rules of natural history and treatment as it is known for adolescent and adult patients with scoliosis. The natural history and treatment options are different and often more complex when curves develop before the age of five.
X-ray criteria can distinguish progressive cases from those that will resolve on their own. Severe heart and lung problems can occur in untreated, progressive cases. A variety of diagnoses may be responsible and each child may require a different evaluation to identify commonly associated problems and different types of treatment. Imaging studies such as an MRI of the central nervous system may be indicated to rule out occult lesions. The most likely natural history, in regards to the spinal growth, curve progression and breathing function, must be determined and treatment should be planned accordingly.
Traditional non-surgical treatment options for early onset scoliosis include body casts, bracing or a combination of two. Skeletal traction may occasionally be helpful in combination with surgery.
Surgical treatment should be strongly considered when non-surgical measures fail to arrest progression. Surgical methods continue to evolve and are primarily directed at obtaining and maintaining correction of the curve while, at the same time, preserving growth of the chest wall and spine.
Traditional posterior (approach from the back) spinal fusion with or without implants (rods, hooks, screws, etc.) is often supplemented by anterior (approach from the side) fusion in young children to prevent crankshaft deformity that can occur in this age group. However, this type of fusion results in permanent torso and chest wall shortening.
Hemiepiphysiodesis of the curve (fusing only one side of the spine) with or without spinal implants is another surgical method to allow progressive correction and prevent worsening of the curve(s). This technique is most effective in congenital curves where the growth is not equal and a gradual correction may be expected. However, the technique does not reverse curve progression.
Recent studies on non-fusion techniques using advanced technology have shown significant improvement in obtaining growth and helping with lung function over previously reported series. These techniques involve both posterior and anterior approaches. Experience with anterior non-fusion techniques are reported more often with older children with Idiopathic Scoliosis. Experience with posterior growing rod techniques has shown some promise in younger children with progressive curves while the rib prosthesis is more successful in children with stiff curves, mostly with congenital origin.
In a multi-center study reported during the Annual Meeting of the Scoliosis Research Society, we reported improved correction and maintenance of growth with a dual growing rod technique utilizing a rod connector through which the rods are periodically lengthened. These children are brought to surgery as an outpatient admission every 6 to nine months for lengthening.
The children who had surgery were followed from 2 to 9 years. The scoliosis curve improved from 82° to 38° at latest follow-up. Kyphosis was 50° pre-op and 45° at follow-up. T1-S1 length, which indicates growth, increased from 23 cm to 28 cm after first surgery (elongation) and to 32 cm at follow-up. In addition to initial elongation averaging 5 cm, the length increase over the follow-up period was an average of 0.87 cm per year. Seven patients had their final fusion. For these patients, the length achieved was 1 cm per year. The space available for the lung also improved following this technique using Campbell ’s criteria. Complications including implant related problems and infection were much less than older techniques using only a single rod.
It appears that the dual growing rod technique provides superior stability, maintains correction and reduces the complication rate. This method of surgical treatment allows continued spinal growth and improved lung volume in this challenging patient population. This is an on going study and long-term follow-up is needed to confirm our findings.