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.

The effect of cage type on local and total cervical lordosis restoration and global spine alignment in single-level anterior cervical discectomy and fusion based on EOS® imaging: A comparison between standalone conventional interbody polyether ether ketone cage and integrated cage and plate (Perfect-C®).

Background: There is a small level of evidence regarding the alterations in global spine alignment following the restoration of cervical lordosis using anterior cervical discectomy and fusion (ACDF). Different cage types are available to restore cervical lordosis through ACDF. In this study, we evaluate the impact of two types of these cages on local and global spine alignments. Patients and Methods: Thirty-two patients with a mean age of 46 ± 10 who underwent ACDF for cervical disc herniation were included in this retrospective study. Patients were divided according to their cage type into two groups, 17 patients with standalone conventional polyether ether ketone cages and 15 patients with integrated cage and plate (ICP) (Perfect-C®). Cervical alignment and global spine alignment were evaluated on the pre- and post-operative EOS® images. Results: Three months after the ACDF, total cervical lordosis correction was higher in patients with ICP (P = 0.001), while the local cervical lordosis correction was not significantly different between conventional cages and prefect-C cages (P = 0.067). Lumbar lordosis and pelvic tilt change were significantly higher among patients with Perfect-c cages (P = 0.043). Conclusion: In patients undergoing ACDF, alignment of the global spine changes along with the restoration of the cervical spine. Cage type affects this association, mainly through the compensatory alteration of pelvic tilt.