Experimental: Local infiltration with liposomal bupivacaine

Patients randomized into the liposomal bupivacaine group will receive anesthesia and undergo standard posterior spinal fusion surgery. The local infiltration would occur in a single stage, after instrumentation and correction maneuver is performed, just prior to closure of the deep fascial layer. The dose would be injected via multiple small volume injections into the paraspinal musculature, spaced approximately 1 cm apart.

Active_comparator: Local infiltration with 0.25% bupivacaine with epinephrine

Patients randomized into the 0.25% bupivacaine with epinephrine group will receive anesthesia and undergo standard posterior spinal fusion surgery under the same condition as the intervention group with one exception: the local infiltration will be made up of equal volume of 0.25% bupivacaine with epinephrine. The equal volume of 0.25% bupivacaine with epinephrine will be used in the exact same administration technique as the liposomal bupivacaine group, involving multiple small-volume injections to the paraspinal musculature spaced approximately 1 centimeter apart.