Risk factors for proximal junctional kyphosis in adult spinal deformity after correction surgery: A systematic review and meta-analysis

Objective: This study aimed to conduct a systematic review and meta-analysis to assess the risk factors for proximal junctional kyphosis after the correction surgery of adult spinal deformity. Methods: Relevant studies were systematically retrieved from databases including Cochrane Library, PubMed, and Embase. Based on inclusion and exclusion criteria, literature screening, quality evaluation, and data extraction were conducted. Analysis was performed with Revman 5.3 software. Results: Sixteen studies with 2388 patients, covering 905 cases with proximal junctional kyphosis and 1483 cases without proximal junctional kyphosis, were included in the study. The high-risk factors for the development of proximal junctional kyphosis were found to be high body mass index, osteoporosis, severe fatty infiltration of paravertebral muscles, small functional area of paravertebral muscles, lumbar lordosis over-correction, lack of ligament reinforcement device at the proximal vertebrae and upper instrumented vertebra at the thoracolumbar segment, and pelvic fixation. The results were statistically significant. Conclusion: Evidence from this study has revealed that the independent risk factors for proximal junctional kyphosis complications after correction surgery of adult spinal deformity are high body mass index, osteoporosis, severe degeneration of paravertebral muscles, lumbar lordosis overcorrection, fixed fusion to the pelvis, and lack of ligament reinforcement device at the proximal vertebrae and upper instrumented vertebra at the thoracolumbar segment. Level of Evidence: Level IV, Therapeutic Study