Thoracic adverse events following spinal manipulative therapy: a systematic review and narrative synthesis

Objectives: Spinal manipulative therapy (SMT) is widely used by manual therapists to manage spinal complaints. Notwithstanding the perceived relative safety of SMT, instances of severe thoracic adverse events (AE) have been documented. An evidence synthesis is required to understand the nature, severity and characteristics of thoracic AE following all SMT. The primary objective of this study was to report thoracic AE following SMT and secondly to report patient characteristics to inform further research for safe practice. Methods: A systematic review and data synthesis were conducted according to a registered protocol (PROSPERO CRD42019123140). A sensitive topic-based search strategy for key databases, gray literature and registers used study population terms and keywords, to search to 12/6/19. Two reviewers were involved at each stage. Using the Oxford Center for Evidence-based Medicine (CEBM) the level evidence was evaluated with grade presented for each AE. Results were reported in the context of overall quality. Results: From 1013 studies identified from searches, 19 studies (15 single case studies and 4 case series) reporting 21 unique thoracic AE involving the spinal cord tissues [nonvascular (n = 7), vascular (n = 6)], pneumothorax or hemothorax (n = 3), fracture (n = 3), esophageal rupture (n = 1), rupture of thoracic aorta (n = 1), partial pancreatic transection (n = 1). Reported outcomes included fully recovery (n = 8), permanent neurological deficit (n = 5), and death (n = 4). Conclusion: Although causality cannot be confirmed, serious thoracic AE to include permanent neurological deficit and death have been reported following SMT. Findings highlight the importance of clinical reasoning, including pre-thrust examination, as part of best and safe practice for SMT.