Unplanned Reoperations in Magnetically Controlled Growing Rod Surgery for Early Onset Scoliosis With a Minimum of Two-Year Follow-Up.

STUDY DESIGN: A retrospective review of prospectively collected clinical and radiologic data of patients with magnetically controlled growing rods (MCGRs) from a multi-centered study with a minimum of 2-year follow-up.

OBJECTIVE: The aim of this study was to describe the incidence and causes of unplanned reoperations and to report the outcomes of patients treated with MCGR for early-onset scoliosis (EOS).

SUMMARY OF BACKGROUND DATA: Published clinical studies have demonstrated that MCGR is safe and effective for curvature control of EOS, and can avoid repeated surgeries for distractions. However, there have been no reports on the unplanned reoperations and complications of MCGR for EOS with a large series of patients.

METHODS: Between 2009 and 2012, 30 patients with EOS underwent MCGR implantation in six institutions. A retrospective review of prospectively collected clinical and radiologic data with a minimum of 2-year follow-up was conducted. Demographic data, radiologic measurements, unplanned reoperations, and other complications were noted. Risk factors for unplanned reoperations were analyzed.

RESULTS: Patients underwent MCGR implantation at the mean age of 7.2 years. The mean follow-up period was 37 months. Fourteen patients (46.7%) underwent an unplanned reoperation within the follow-up period, with a mean time to reoperation of 23 months after initial surgery (range, 5-48 months). Causes of unplanned reoperation were failure of rod distractions, proximal foundation failure, rod breakage, and infection. More frequent distractions (between 1 week and 2 months) were associated with a higher rate of reoperation than distraction frequencies between 3 and 6 months (71% vs. 25%).

CONCLUSION: This is the largest series with the longest follow-up to date that examines the need for additional unplanned surgery after the initial procedure. It highlights that MCGR surgery can be associated with unplanned reoperations, and more frequent distractions may be a risk factor. Long-term comparative studies with traditional growing rod are required to evaluate the effectiveness of this implant.

LEVEL OF EVIDENCE: 4.