Factors Related to Proximal Junctional Kyphosis and Device Failure in Patients with Early-Onset Scoliosis Treated with a Traditional Dual Growing Rod: A Single Institution Study

Study Design: Observational study.Purpose: Investigation of factors related to proximal junctional kyphosis (PJK) and device failure in patients with early-onset scoliosis.Overview of Literature: The use of growth-friendly devices, such as traditional dual growing rod (TDGR) for the treatment of earlyonset scoliosis (EOS), may be associated with important complications, including PJK and device failure.Methods: Thirty-five patients with EOS and treated with TDGR from 2014 to 2021 with a minimum follow-up of 2 years were retrospectively evaluated. Potential risk factors, including demographic factors, disease etiology, radiological measurements, and surgical characteristics, were assessed.Results: PJK was observed in 19 patients (54.3%), and seven patients (20%) had device failure. PJK was significantly associated with global final kyphosis change (p=0.012). No significant correlation was found between the rod angle contour, type of implant, connector design, and the risk of PJK or device failure.Conclusions: Treatment of EOS with TDGR is associated with high rates of complications, particularly PJK and device failure. The device type may not correlate with the risk of PJK and device failure. The progression of thoracic kyphosis during multiple distractions is an important risk factor for PJK.