Distal junctional failure in posterior cervical and cervicothoracic fusion: A systematic review and meta-analysis of associated factors.

PURPOSE: Distal junctional kyphosis (DJK) is a significant complication following posterior cervical or cervicothoracic fusion. Despite the increasing number of these procedures, the factors associated with DJK remain underexplored, particularly compared to proximal junctional kyphosis. This systematic review and meta-analysis aimed to identify key factors associated with DJK and provide actionable recommendations for its prevention.

METHODS

A comprehensive search of PubMed, Scopus, Embase, and Web of Science was conducted to identify case-control and cohort studies reporting on factors associated with DJK in adult patients undergoing posterior cervical or cervicothoracic fusion. Data on demographics, radiographic parameters, and surgical factors were extracted. Meta-analysis was performed using a random-effects model, with odds ratios (OR) and standardized mean differences (SMD) calculated for significant variables.

RESULTS

DJK occurred in 15.2% of patients across the included studies. Significant associated factors included osteoporosis, preoperative cervical kyphosis greater than 3.4°, preoperative C2-C7 sagittal vertical axis (cSVA) exceeding 30 mm, postoperative residual cSVA exceeding 32 mm, a T1 slope change greater than 6 degrees, fusions involving more than five levels, and selecting the lowest instrumented vertebra (LIV) in the lower thoracic or thoracolumbar regions.

CONCLUSION

Optimizing sagittal alignment, addressing osteoporosis, and carefully selecting the lowest instrumented vertebra may help reduce DJK incidence in posterior cervical and cervicothoracic fusion surgeries. Future prospective studies are needed to refine prevention strategies and improve patient outcomes.