Management and Risk Factors of Fracture-Type Proximal Junctional Kyphosis: Focus on Myelopathy and Intervention.

Study DesignRetrospective observational study.ObjectivesTo identify radiographic and clinical predictors of fracture-type proximal junctional kyphosis (PJFx) and associated myelopathy (PJFx-M), with the goal of facilitating timely surgical intervention.MethodsWe retrospectively reviewed 438 patients with adult spinal deformity who underwent long-segment fusion surgery at our institution between 2013 and 2023. Risk factors for PJFx and PJFx-M were analyzed, focusing on demographic and radiographic parameters. In PJFx-M cases, we specifically assessed sliding length, screw protrusion, and superior articular facet fractures.ResultsPJFx occurred in 102 patients (23.3%). Significant risk factors for PJFx included a lower Hounsfield unit (HU) value at the upper instrumented vertebra (UIV) and reduced preoperative lumbar lordosis. PJFx-M was identified in 10 patients (2.3%). Radiographic predictors of PJFx-M included increased sliding length, screw protrusion into the upper vertebra, and bilateral superior articular facet fractures (all < 0.001). Additionally, a fall within 1 month of symptom onset was frequently observed in PJFx-M cases. PJFx-M was not associated with demographic factors or body mass index.ConclusionsLower HU at the UIV and reduced preoperative lumbar lordosis were key predictors of PJFx. PJFx-M should be suspected in the presence of increased sliding length, screw protrusion into the upper vertebra, superior articular facet fractures, and a recent fall. These findings highlight the importance of vigilant postoperative radiographic and clinical monitoring to enable early detection and intervention, potentially preventing neurological deterioration.