Adjunctive intraosseous ropivacaine administration using a gelatin sponge carrier during percutaneous kyphoplasty: a retrospective cohort study

Patients undergoing percutaneous kyphoplasty (PKP) under conventional local anesthesia may experience substantial pain during bone cement injection. We evaluated adjunctive intraosseous analgesia (IA), consisting of intraosseous administration of ropivacaine using a gelatin sponge carrier, in addition to conventional local anesthesia. This single-center retrospective cohort study included 91 patients who underwent PKP for single-level osteoporotic thoracolumbar vertebral compression fractures. Patients received conventional local anesthesia with 100 mg ropivacaine (LA group, n = 46) or the same local anesthesia combined with adjunctive intraosseous administration of an additional 50 mg ropivacaine using a gelatin sponge carrier (IA group, n = 45; total dose, 150 mg). Both techniques were used contemporaneously and were selected according to routine clinical practice and preoperative surgeon–patient discussion. The primary outcome was the highest visual analog scale (VAS) score during bone cement injection. Multivariable linear regression was used to analyze the primary outcome, and Firth-penalized logistic regression was used for the exploratory analysis of fluoroscopically detected bone cement leakage. The intraoperative VAS score was lower in the IA group than in the LA group (3.09 ± 0.67 vs. 5.11 ± 0.71). This association remained after adjustment for prespecified demographic, clinical, fracture-related, and calendar-time covariates (adjusted mean difference, −2.00; 95% confidence interval [CI], −2.32 to −1.67; P < 0.001). Fluoroscopically detected bone cement leakage occurred in 6 of 45 patients in the IA group and 17 of 46 patients in the LA group; the association remained after adjustment in the Firth-penalized logistic regression model (adjusted odds ratio [OR], 0.28; 95% CI, 0.09–0.75; P = 0.011). No clinically apparent local anesthetic systemic toxicity or other serious anesthesia-related adverse events were documented before hospital discharge. Adjunctive intraosseous ropivacaine administration using a gelatin sponge carrier was associated with lower patient-reported pain during bone cement injection. The intervention was technically feasible in this cohort, and no clinically apparent serious anesthesia-related adverse events were documented. Prospective controlled studies with pharmacokinetic assessment are needed to confirm the analgesic effect and characterize safety. Not applicable.