P120. The efficacy and safety of applying ultrasonic osteotome in cervical expansive open-door laminoplasty

Abstract

BACKGROUND CONTEXT Ultrasonic osteotome is a tissue-specific device which offers potential advantages of more precise bone resection, reduced soft-tissue injury, and less demand in surgical skill, and have been used widely in spinal surgery. Yet few studies have investigated its safety and efficacy until now. PURPOSE To investigate the safety and efficacy of applying ultrasonic osteotome in patients undergoing cervical expansive open-door laminoplasty. STUDY DESIGN/SETTING Retrospectiviely we collected the patients' clinical data and the follow-up image. All the patients were diagnosed as multilevel cervical spondylosis myelopathy and underwent cervical expansive open-door laminoplasty. Then we divided these patients into two groups: ultrasonic osteotome group and traditional group, by whether the ultrasonic osteotome device was used in operation. PATIENT SAMPLE From March 2015 to March 2016, 94 consecutive patients who were administrated in the spine group of orthopedic department of Peking University Third Hospital were reviewed retrospectiviely. OUTCOME MEASURES Comparison was made between the traditional method using bone rongeur or high-speed grinding, and the piezosurgery group. Duration of operation (from skin incision to closure), blood loss during surgery, volume of drainage first day after operation, remaining of drainage tube, and occurrence of cerebrospinal fluid leak were assessed between the two groups. JOA spinal cord function scoring system (17-point method) was adopted to evaluation neurological function. JOA score before operation, 3 months after operation, 12 months after operation and JOA improvement rate was compared between two groups. JOA improvement rate = (postoperative JOA score - preoperative JOA score) / (17 - preoperative JOA score) × 100%. Three months and 12 months follow-up CT scans were used to evaluate portal shaft healing by assessing C4, C5, and C6 portal bones. METHODS From March 2015 to March 2016, 94 consecutive patients who were administrated in the spine group of orthopedic department of Peking University Third Hospital were reviewed retrospectiviely. All the patients were diagnosed as multilevel cervical spondylosis myelopathy and were underwent cervical expansive open-door laminoplasty. These patients were divided into two groups: ultrasonic osteotome group and traditional group, by whether the ultrasonic osteotome device was used in operation. The parameters we studied were as follows: the duration of operation, blood loss in operation, volume of drainage at the first postoperative day, days of remaining the drainage tube, preoperative and postoperative JOA score, complication of cerebrospinal fluid leak and hinge bone nonunion. RESULTS Comparing to the traditional group, the duration of operation of the ultrasonic osteotome group was increased, but the blood loss in operation, volume of drainage at the first postoperative day and days of remaining the drainage tube of the ultrasonic osteotome group were all reduced. There is no obvious difference between the two groups when considering the cerebrospinal fluid leak. At the 3 month follow-up, the JOA score and improvement rate of JOA score showed no obvious difference between the two groups. But the hinge bone union of the traditional group is better than the ultrasonic osteotome group. At the 12 month follow-up, all the JOA score, the improvement rate of JOA score and the hinge bone union were not obviously different between the two groups. CONCLUSIONS Applying ultrasonic osteotome in patients undergoing cervical expansive open-door laminoplasty is both safe and effective. Comparing with the rongeur, ultrasonic osteotome caused the delayed union of the hinge bone, but it reduces the blood loss in operation, volume of postoperative drainage and days of remaining the drainage tube. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.