158 - Results and Complications of Magnetically Controlled Growing Rods for...

#158 Results and Complications of Magnetically Controlled Growing Rods for Early Onset Scoliosis at 18-Months Follow-up

Pediatric Spine

Poster Presented by: G. La Rosa

Author(s):

G. La Rosa (1)
L. Ruzzini (1)
L. Oggiano (1)

(1) Bambino Gesù Children’s Hospital, IRCCS, Department of Surgery and Transplants Center - Orthopedic Unit, Rome-Fiumicino, Italy

Abstract

The surgical treatment of severe spinal deformities in young children affected by EOS is challenging as definitive or extensive spinal fusion would result in severe loss of growth, short trunk and severe pulmonary deficiency. The use of expandable instrumentation, which could control the progression of scoliosis without affecting the growth of the spine and hence promoting pulmonary development is widening. All growing-rods techniques implicate repeated surgeries at intervals of 6 to 9 months to lengthen the rods in order to allow spinal growth; once maximum spinal growth and bone age has been reached, definitive spinal fusion is performed. For this reason a new method for the management of such kind of scoliosis has been recently introduced: it consists in a magnetically controlled growing rod that allow gradual outpatient distractions through an external remote control device.

To present our series of patients affected by early onset scoliosis (EOS) and managed with magnetically controlled growing rods (Ellipse TM MAGEC System). The sample consists of 7 patients affected by early onset scoliosis in which we implanted magnetically controlled growing rods. Scoliosis and kyphosis angles, T1-T12 and T1-S1 distances were evaluated preoperatively, postoperatively and at the last follow-up. A visual analog scale score was used to evaluate pain during outpatient rod distraction procedures.

The mean follow-up is 18 months. All patients attended at least three outpatient distractions of the magnetic rod through an external remote control every three months. We used plain radiography to measure the magnitude of the spinal curvature, rod distraction length, and spinal length.

The mean curve was 69.1° ± 18,2° degrees (range 52°-100°) preoperatively and 27,4°± 14,5° degrees (range 15°-59°) immediately after surgery showing a statistically significant (p< 0.05) mean correction of 41,7° degrees (range 36°-56°) (60,3% of the initial scoliosis angle).

The mean kyphosis angle was 45.6° ± 20,4° degrees (range 20°-85°) preoperatively and 31,1°± 12,9° degrees (range 15°-55°) immediately after surgery showing a statistically significant (p< 0.05) mean correction of 14,5° degrees (range 5°-30°) (31,7 % of the initial kyphosis angle).

When measuring the total mean spinal growth length between the preoperative to the immediate postoperative final radiographs, the increase in T1 and S1 length was statistically significantly (p< 0.05) improved from a mean value of 26,7 ± 6,2 cm (range 16-34,8 cm) to a mean postoperative value of 31,5 ± 4,2 cm (range 25,1-36,8 cm). Also T1-T12 length showed a statistically significant (p< 0.05) improvement from a mean preoperative value of 16,1 ± 3,1 cm (range 10-18,5 cm) to a mean postoperative value of 19,1 ± 2,5 cm (range 15,2-21,6 cm).

The mean predicted gain in rod length per distraction was 3 mm; the mean actual instrumented segment length gain per distraction was 2,1 mm showing a mean difference between predicted and real lengthening of 32%. One patient (a case of severe hyperkyphosis) had a rod breakage and one patient had a pool-out of the proximal hooks.

Magnetically controlled growing rods can be safely and effectively used in patients affected by early onset scoliosis. This procedure can be effectively used in outpatient settings, minimising surgical scarring and psychological distress, improving quality of life and saving healthcare costs.