86. Rate of revision surgery following multilevel posterior cervical fusion at the cervicothoracic junction

Abstract

BACKGROUND CONTEXT Recently the optimal caudal extent of multileval posterior cervical fusion in relation to the cervicothoracic junction has been debated in the literature. PURPOSE The purpose of this study is to compare the reoperation rate in patients who have had a posterior cervical laminectomy and fusion where the caudal extent of the fusion terminates cranial vs caudal to the cervicothoracic junction. The primary end point of this study is the reoperation rates within 1-year follow-up for each of the two groups. The secondary end points are comparisons of time to revision between the two groups and radiographic outcomes. STUDY DESIGN/SETTING Retrospective chart and radiographic review of patients at a single center between 9/1/2013 and 1/21/2016 who underwent multilevel posterior laminectomy and fusion with additional telephone follow-up to assess the presence of further surgical procedures. All surgeries were performed by one of two fellowship-trained orthopedic spine surgeons. Exclusion criteria included presence of trauma, tumor, or infection, and patients who had cervical surgery prior to posterior fusion. Preoperative, postoperative, and 1-year follow-up radiographs were assessed with C2-C7 SVA and lordosis. PATIENT SAMPLE Seventy-eight patients met inclusion criteria; 54 male and 24 female. Sixty-two patients had posterior constructs that terminated and C7 and 16 patients had constructs terminating from T1-T4. There was no significant difference in age, gender, diagnosis/reason for surgery, length of follow-up, or BMI. Average follow-up for both groups was 51 months. RESULTS There were a total of 13 revision surgeries in 12 patients whose constructs' caudal extent was C7 vs 2 revisions in patients whose caudal extent was in the thoracic spine. There was no significant difference in revision rate between the two groups. There was no difference in time to revision between the two groups. The median time to revision was 35 days and time to revision was widely distributed from 7 to 774 days. There was no difference in preoperative or postoperative cervical lordosis between the two groups. The C7 group had a lower preoperative SVA than the more caudal T1-4 group (39 vs 55) but no difference in postoperative SVA was detected (P value >.05). CONCLUSIONS It is likely that regional variations in the indications for revision surgery, variations in patient populations, and surgeon bias explain much of the differences seen in the current literature regarding where to end a multilevel posterior cervical fusion. Our study, along with others, suggests that similar revision rates and radiographic outcomes can be achieved with ending the fusion at C7 or extending it into the thoracic spine. Including the upper thoracic spine in the construct appears to be a reasonable option if there are concerns about bone quality, implant fixation in the lateral mass or pedicles of C7, tobacco use, or sagittal alignment issues. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.