Shilla growth guidance system (SGGS) instrumentation with pelvic foundation for severe early-onset neuromuscular spine deformity.

Abstract

To present our experience using Shilla Growth Guidance System (SGGS) technology with a solid pelvic foundation in patients with severe early-onset neuromuscular spine deformity. The surgical procedure involved a solid instrumented fusion from L5 to the pelvis with iliac screws, with minimal dissection of the spine from L4 to T4, leaving the longitudinal para-spinal muscles intact. Alternating SGGS screws were sequentially placed from L4 to T4 with fluoroscopy and/or computer navigation. This retrospective study from two institutions included surgeries performed by three surgeons. The primary outcomes were the number of revision surgeries and the complication rate; T1-S1 height increase was a secondary outcome. For 34 patients, the average age at the initial surgery was 5.9 years and the follow-up was 10 years for surviving patients. Eleven patients were tracheostomy- and ventilator-dependent. The average total number of surgeries/patients was 2.3. The revision surgery rate was 53% (45 revision surgeries in 18 patients, average of 2.5 revision surgeries/patient). 20 patients (59%) had a major complication (modified Clavien-Sink-Dindo classification 3a-5). Nine (26%) had a deep surgical-site (SSI) infection requiring irrigation, debridement, and implant exchange. Thirteen patients died at an average age of 10.7 years, average 4.7 years post-operative, a 38% 10-year mortality and representing the frail nature of this population. Ten of these 13 (77%) deceased patients had no additional surgery after their index surgery, which was one of the major goals of the procedure. Nine of the 34 patients (26%) had a final fusion. The T1-S1 height increased by a mean of 6.7 cm (p < 0.01). SGGS with a solid pelvic foundation is an option for addressing severe spinal deformity for patients with early-onset neuromuscular scoliosis who are too immature for a definitive fusion. For 47% of these patients, only the initial surgical procedure was necessary, thus avoiding serial surgical or clinic lengthening procedures. However, the revision rate of 53% and complication rate of 59% demonstrates the high risks of this procedure in this extremely frail population.