Risk Factors for Recurrent Proximal Junctional Failure Following Adult Spinal Deformity Surgery: Analysis of 60 Patients Undergoing Fusion Extension Surgery for Proximal Junctional Failure

Abstract

Background: Despite numerous studies identifying risk factors for proximal junctional failure (PJF), risk factors for recurrent PJF (R-PJF) are still not well established. Therefore, we aimed to identify the risk factors for R-PJF following adult spinal deformity (ASD) surgery. Methods: Among 479 patients who underwent ? 5- level fusion surgery for ASD, the focus was on those who experienced R-PJF at any time or did not experience R-PJF during a follow- up duration of ? 1 year. PJF was defined as a proximal junctional angle (PJA) ? 28 degrees plus a difference in PJA ? 22 degrees or performance of revision surgery regardless of PJA degree. The patients were divided into 2 groups according to R-PJF development: no R-PJF and R-PJF groups. Risk factors were evaluated focusing on patient, surgical, and radiographic factors at the index surgery as well as at the revision surgery. Results: Of the 60 patients in the final study cohort, 24 (40%) experienced R-PJF. Significant risk factors included greater postoperative sagittal vertical axis (OR = 1.044), overcorrection relative to age- adjusted pelvic incidence-lumbar lordosis (PI- LL; OR = 7.794) at the index surgery, a greater total sum of the proximal junctional kyphosis severity scale (OR = 1.145), and no use of the upper instrumented vertebra cement (OR = 5.494) at the revision surgery. Conclusions: We revealed that the greater postoperative sagittal vertical axis and overcorrection relative to age- adjusted pelvic incidence-lumbar lordosis at the index surgery, a greater proximal junctional kyphosis severity scale score, and no use of upper instrumented vertebra cement at the revision surgery were significant risk factors for R-PJF. Clinical Relevance: To reduce the risk of R-PJF after ASD surgery, avoiding under- and overcorrection during the initial surgery is recommended. Additionally, close assessment of the severity of PJF with timely intervention is crucial, and cement augmentation should be considered during revision surgery.