Augmented Central Pain Processing Occurs after Osteoporotic Vertebral Compression Fractures and Is Associated with Residual Back Pain after Percutaneous Vertebroplasty.

Study design: A retrospective analysis.

Purpose: To investigate the occurrence of central sensitization (CS) in patients with osteoporotic vertebral compression fractures (OVCFs) and identify the association between CS and residual back pain (RBP).

Overview of literature: RBP is a vexing complication that affects 6.3%-17.0% of patients with OVCFs who underwent percutaneous vertebroplasty (PVP). Given the negative effect of RBP on patients' psychological and physiological statuses, efforts to preoperatively select patients who are at risk for RBP development have a high priority to offer additional treatment and minimize this complication.

Methods: Preoperatively, all 160 patients with OVCFs underwent pressure-pain threshold (PPT), temporal summation (TS), conditioned pain modulation (CPM), and imaging assessments. Pain intensity and pain-related disability were evaluated before and after PVP.

Results: Preoperatively, patients with OVCFs had lower PPTs in both local pain and pain-free areas and lower CPM and higher TS in pain-free areas than healthy participants (p<0.05). Unlike patients with acute fractures, patients with subacute/chronic OVCFs showed higher TS with or without lower CPM in the pain-free area compared with healthy participants (p<0.05). Postoperatively, RBP occurred in 17 of 160 patients (10.6%). All preoperative covariates with significant differences between the RBP and non-RBP groups were subjected to multivariate logistic regression, showing that intravertebral vacuum cleft, posterior fascia edema, numeric rating pain scale scores for low back pain at rest, and TS were independently associated with RBP (p<0.05).

Conclusions: Augmented central pain processing may occur in patients with OVCFs, even in the subacute stage, and this preexisting CS may be associated with RBP. Preoperative assessment of TS in pain-free areas may provide additional information for identifying patients who may be at risk of RBP development, which may be beneficial for preventing this complication.