[Application of ultrasonic bone knife in osteotomy of degenerative kyphosis].

To explore the safety and effectivity of ultrasonic bone knife in osteotomy of degenerative kyphosis.The clinical data of 32 patients with degenerative kyphosis treated from February 2014 to May 2016 were retrospectively analyzed. There were 12 males and 20 females, aged 50 to 71 years with an average of (62.1±12.3) years. Preoperative Cobb angle was 25.3° to 36.7° with an average of (28.6±10.2) °. All patients underwent multi-segment Ponte osteotomy combined with posterior long segmental internal fixation. According to different osteotomy tools, the patients were divided into traditional tool group (group A, 18 cases) and ultrasonic bone knife group (group B, 14 cases). The operation time, laminectomy time, number of osteotomy segments, intraoperative blood loss, postoperative drainage, hospitalization time and postoperative complications were recorded.Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate clinical outcomes before and 1 month after surgery.All the patients were followed up from 8 to 24 months with an average of 16.4 months. There were no significant differences in operative time and hospitalization time between two groups (P>0.05). Intraoperative single laminectomy time of group A was more than that of group B (P<0.05). The number of osteotomy segments in group A was less than that in group B (P<0.05). Intraoperative blood loss and postoperative drainage in group A were more than that in group B (P<0.05). There were no significant differences in VAS and ODI between two groups (P>0.05). There were no dural, nerve and spinal cord injuries in both groups, and there were no complications such as improper operation of the instrument and nonunion of the osteotomy.The use of ultrasonic bone knife for Ponte osteotomy is safe and effective. It can effectively save the time of single laminectomy while reducing the amount of intraoperative blood loss and postoperative drainage. The safety and clinical efficacy of ultrasonic bone knife are no less than traditional tools.