Preemptive Infiltration With Betamethasone and Ropivacaine for Postoperative Pain in Laminoplasty or Laminectomy

The local infiltration solution in the treatment group will consist of betamethasone and ropivacaine. For local infiltration, a total of 30 ml solution will be prepared for each group, which will include 0.5ml of compound betamethasone injection(betamethasone propionate 5mg and betamethasone sodium phosphate 2mg per 1ml) added to 14.5ml of saline and 15ml of 1% ropivacaine. The surgeon will perform wound infiltration after induction of anesthesia and before surgery. A total of 10 ml of solution will be injected into each level. The study solution will be injected into the subcutaneous tissue, paravertebral muscles, along with the posterior area around the spinous process, lamina, transverse process and the facet joints, along both sides of the planned incision. The epidural space and intrathecal space will not be infiltrated.

The local infiltration solution in the control group will consist of ropivacaine. For local infiltration, a total of 30 ml solution will be prepared for each group, which will include 15ml of ropivacaine added to 15 ml of saline for the Control group. The surgeon will perform wound infiltration after induction of anesthesia and before surgery. A total of 10 ml of solution will be injected into each level. The study solution will be injected into the subcutaneous tissue, paravertebral muscles, along with the posterior area around the spinous process, lamina, transverse process and the facet joints, along both sides of the planned incision. The epidural space and intrathecal space will not be infiltrated.