Proximal Junctional Failure After Adult Spinal Deformity Surgery

This meta-analysis pooled 28 retrospective cohort studies (4560 patients) to find predictors of proximal junctional failure (PJF) after adult spinal deformity surgery, which occurred in 23.3% of patients. PJF was linked to older age, worse baseline disability/pain, greater preoperative sagittal malalignment (higher pelvic tilt, SVA, PI-LL mismatch, lower lumbar lordosis), and poorer local bone quality, most strikingly lower CT-derived Hounsfield units at the upper instrumented vertebra (mean difference -28.97 HU) and the level above (-32.67 HU), with HU showing good diagnostic discrimination for PJF (pooled AUC 0.86). Notably, fusion length and UIV level (above/below T10) were not associated with PJF, suggesting risk depends more on alignment demands and bone competence than construct size alone.

AI summary · from the full text · reviewed by Pukhraj Gaheer, Medical Student, Queen's University before publishing

Why it mattersPJF is a common, morbid complication of deformity surgery, and this synthesis suggests opportunistic Hounsfield unit measurement from routine preoperative CT could help surgeons flag high-risk patients before choosing fusion strategy.

Presenting this at rounds? Start here

• ?If a patient has low Hounsfield units at the planned upper instrumented vertebra along with severe sagittal malalignment, should surgeons routinely delay surgery for bone-health optimization or modify the construct (e.g., choosing L5 over sacral/pelvic fixation) to reduce PJF risk?
• ?Given that binary osteoporosis diagnosis was not predictive but continuous DEXA T-score and CT attenuation were, should preoperative osteoporosis screening for deformity surgery shift away from a simple osteoporosis/non-osteoporosis label toward routine opportunistic HU reporting on staging CTs?