Effectiveness of Thoracic Paravertebral Block in Minimally Invasive Vertebroplasty: A Retrospective Cohort Study Focusing on Pain Trajectories and Sagittal Spinal Alignment.

PURPOSE: To evaluate the effectiveness of ultrasound-guided thoracic paravertebral block (TPVB) combined with general anesthesia (GA) versus GA alone in improving postoperative pain trajectories, reducing opioid consumption, and enhancing sagittal spinal alignment in patients undergoing minimally invasive vertebroplasty (MIVP) for osteoporotic vertebral compression fractures.

DESIGN

Retrospective cohort study with 1:1 propensity score matching.

METHODS

Electronic medical records from a tertiary academic hospital were analyzed for patients aged ≥50 years undergoing single-level MIVP (T10-L2) between 2020-2023. The TPVB+GA group (n=168) received ultrasound-guided TPVB (≥10 mL 0.2-0.5% ropivacaine) plus GA, while the GA-only group (n=168) received GA alone. Pain trajectory clusters were derived from nursing documentation using natural language processing and machine learning (dynamic time warping with k-means clustering). Sagittal alignment was assessed via pelvic incidence-lumbar lordosis mismatch (PI-LL) and sagittal vertical axis (SVA) on EOS radiographs at 3 months. Secondary outcomes included 72-hour opioid consumption (morphine milligram equivalents) and safety events.

FINDINGS: Three distinct pain trajectories were identified: rapid resolvers (58%, predominantly TPVB+GA), persistent pain (24%, predominantly GA-only), and rebound pain (18%). TPVB+GA significantly reduced persistent pain risk (adjusted odds ratio=0.36, 95% CI 0.21-0.61, p<0.001; number needed to treat=4.2). At 3 months, the TPVB+GA group demonstrated superior sagittal alignment (PI-LL: 6.8±3.1° vs 9.5±4.2°, p<0.001; SVA: 32.4±18.7 vs 45.6±22.3 mm, p<0.001), which correlated with early C-reactive protein reduction (r=0.42, p=0.003). Opioid consumption within 72 hours was 42% lower (24.5±8.7 vs 42.1±12.3 mg, p<0.001). Safety outcomes were comparable between groups (TPVB-related complications: 3.6%; surgical complications: p>0.05).

CONCLUSIONS

Ultrasound-guided TPVB combined with GA significantly improves postoperative pain trajectories, reduces opioid consumption, and enhances sagittal spinal alignment in MIVP patients. TPVB may modulate nociceptive and neuroinflammatory pathways, offering a safer analgesic option for spinal surgery in osteoporotic patients. Prospective randomized trials are warranted to confirm these findings.