Risk factors of early complications after thoracic and lumbar spinal deformity surgery: a systematic review and meta-analysis

Purpose: To determine risk factors increasing susceptibility to early complications (intraoperative and postoperative within 6 weeks) associated with surgery to correct thoracic and lumbar spinal deformity. Methods: We systematically searched the PubMed and EMBASE databases for studies published between January 1990 and September 2021. Observational studies evaluating predictors of early complications of thoracic and lumbar spinal deformity surgery were included. Pooled odds ratio (OR) or standardized mean difference (SMD) with 95% confidence intervals (CI) was calculated via the random effects model. Results: Fifty-two studies representing 102,432 patients met the inclusion criteria. Statistically significant patient-related risk factors for early complications included neurological comorbidity (OR = 3.45, 95% CI 1.83–6.50), non-ambulatory status (OR = 3.37, 95% CI 1.96–5.77), kidney disease (OR = 2.80, 95% CI 1.80–4.36), American Society of Anesthesiologists score > 2 (OR = 2.23, 95% CI 1.76–2.84), previous spine surgery (OR = 1.98, 95% CI 1.41–2.77), pulmonary comorbidity (OR = 1.94, 95% CI 1.21–3.09), osteoporosis (OR = 1.60, 95% CI 1.17–2.20), cardiovascular diseases (OR = 1.46, 95% CI 1.20–1.78), hypertension (OR = 1.37, 95% CI 1.23–1.52), diabetes mellitus (OR = 1.84, 95% CI 1.30–2.60), preoperative Cobb angle (SMD = 0.43, 95% CI 0.29, 0.57), number of comorbidities (SMD = 0.41, 95% CI 0.12, 0.70), and preoperative lumbar lordotic angle (SMD = − 0.20, 95% CI − 0.35, − 0.06). Statistically significant procedure-related factors were fusion extending to the sacrum or pelvis (OR = 2.53, 95% CI 1.53–4.16), use of osteotomy (OR = 1.60, 95% CI 1.12–2.29), longer operation duration (SMD = 0.72, 95% CI 0.05, 1.40), estimated blood loss (SMD = 0.46, 95% CI 0.07, 0.85), and number of levels fused (SMD = 0.37, 95% CI 0.03, 0.70). Conclusion: These data may contribute to development of a systematic approach aimed at improving quality-of-life and reducing complications in high-risk patients.