To compare the pain relief in spine surgery from a pain killer drug (Ropivacaine) with a placebo (Normal Saline) delivered regionally at the transverse process of the operated vertebrae.

Lumbar spine instrumentation surgery is known to cause an intense pain in the postoperative period. The pain can originate from surgery on the different structures such as vertebrae, intervertebral discs, dura , ligaments ,joint capsule fascia , muscles and skin . The posterior sensory rami of the spinal nerves connected to sympathetic and parasympathetic nerves innervate these structures and transmit the pain sensation. In order to decrease opioids usage and side effects, we propose a method that compare the effect of absorbable gelatin sponge impregnated with local anesthetics versus normal saline placed by the surgeon on the transvers process of the operated vertebra, at the end of the surgery, and before closure of surgical plans, on postoperative visual analogue pain score and the amount of meperidine usage for 48h post-surgery.