Incidences, causes and risk factors of unplanned reoperations within 30 days of spine surgery: a single-center study based on 35,246 patients

Unplanned reoperation, a quality indicator in spine surgery, has not been sufficiently investigated in a large-scale, single-center study.To assess the incidences, causes, and risk factors of unplanned reoperations within 30 days of spine surgeries in a single-center study.Retrospective observational study.A cohort of 35,246 patients who underwent spinal surgery in our hospital were included.The rates, chief reasons, and risk factors for unplanned reoperations within 30 days of spine surgery.We retrospectively analyzed the data for patients who underwent spine surgeries for degenerative spinal disorders, tumor, or deformity and had subsequent unplanned operations within 30 days at a single tertiary academic hospital from January 2016 to July 2021. Univariate and multivariate analyses were performed to assess the incidences, causes, and risk factors.Out of 35,246 spinal surgery patients, 297 (0.84%) required unplanned reoperations within 30 days of spine surgery. Patients with a thoracic degenerative disease (3.23%), spinal tumor (1.63%), and spinal deformity (1.50%) had significantly higher rates of reoperation than those with atlantoaxial (0.61%), cervical (0.65%), and lumbar (0.82%) degenerative disease. The common causes for reoperation included epidural hematoma (0.403%), wound infections (0.148%), neurological deficit (0.108%), and pedicle screw malposition (0.077%). Unplanned reoperations were classified as hyperacute (45.45%), acute (30.98%), subacute (15.82%), or chronic (7.74%). Univariate analysis indicated that 20 clinical factors were associated with unplanned reoperation (p<.05). Multivariate Poisson regression analysis revealed that anemia (p<.001), osteoporosis (p=.048), ankylosing spondylitis (p=.008), preoperative foot drop (p=.011), deep venous thrombosis (p<.001), and previous surgical history (p<.001) were independent risk factors for unplanned spinal reoperation.The incidence of unplanned spinal reoperations was 0.84%. The chief common causes were epidural hematoma, wound infections, neurological deficit, and pedicle screw malposition. Anemia, osteoporosis, ankylosing spondylitis, preoperative foot drop, deep venous thrombosis, and previous surgical history led to an increased risk of unplanned reoperation within 30 days of spine surgery.