Forty patients with cervical degenerative diseases undergoing posterior cervical expansive open-door laminoplasty were randomized to osteotomy using an ultrasonic bone scalpel (UBS) or a high-speed drill (HSD). Surgeons were not blinded, but patients and outcome assessors were blinded. The outcomes included operative time, open-door time, blood loss, postoperative drainage, complications, spinal canal expansion, pain (VAS), bony union at the hinge, and neurological recovery assessed by Japanese Orthopaedic Association (JOA) scores up to 1 year. Overall, the results of the study revealed that the UBS significantly reduced total operative time, open-door time, and postoperative drainage volume compared with HSD, while intraoperative blood loss, complication rates, spinal canal expansion, pain relief, and neurological recovery were similar between groups. These findings suggest that UBS improves surgical efficiency without compromising safety or clinical outcomes.