Predictive Factors for APJF after Adult Deformity Surgery with the UIV in the Thoracolumbar (TL) Spine

Abstract

Acute Proximal Junctional Failure (APJF), was recently defined by the International Spine Study Group (ISSG) as: postoperative fracture of the upper instrumented vertebrae (UIV) or UIV+1; UIV implant failure; proximal junctional kyphosis (PJK) increase ≥15°; or need for proximal extension of the fusion within 6 months of surgery. The incidence and revision rates of APJF have been reported to be higher when the UIV is located in the lower thoracic or lumbar (TL) spine mostly because of high incidence of UIV or UIV+1 fractures.