297. Preoperative extension lateral cervical radiographs are associated with osteotomy type, approach and postoperative cervical alignment following cervical deformity surgery

Abstract

BACKGROUND CONTEXT Choosing the surgical approach and osteotomy type is challenging when surgically treating cervical deformity. Preoperative assessment of flexibility and final alignment would be useful for surgeons treating this complex problem. Currently extension lateral XR are inconstantly taken for the management of cervical deformity for planning purposes. PURPOSE Investigate the relationship of surgical procedure choice and the pre-operative flexibility of the cervical spine. Determine if extension lateral XR (ELXR) can also predict the final postoperative alignment. STUDY DESIGN/SETTING Retrospective review of prospective, consecutively enrolled multicenter cervical deformity database PATIENT SAMPLE A total of 106 cervical deformity patients OUTCOME MEASURES Surgical treatment, radiographic alignment parameters (SS, T1S-CL, cSVA, C2 slope, T1 slope) METHODS A prospective database of operative cervical deformity patients was analyzed. Inclusion was cervical kyphosis>10°, cervical scoliosis>10°, C2-C7 SVA>4cm or chin-brow vertical angle>25°. Patients were excluded if they did not have neutral and ELXR or did not have deformity limited to the cervical or cervicothoracic spine. The ELXR was compared to preoperative neutral lateral, and 3 mo alignment XR and type of surgical osteotomy based upon the Ames Classification. Statistical analysis included t-test and chi-squared. RESULTS A total of 106 from 164 patients met the inclusion criteria. Mean age of 60 yo, with 58% females. Of the study population, 43.4% of patients had prior cervical surgery. The evaluation of ELXR in patients who received grade 1-2 osteotomies (as compared to those who received grade 5,6 or 7), shows they have statistically lower T1S (23.06 vs 35.46; p=.021), lower T1S-CL (20.90 vs 36.29; p=.033), lower cSVA (24.66 vs 48.35; p 17 in the ELXR (46.77% vs 36.36%; p=.033). Overall, while surgery created a significant change in all radiographic parameters; the 3 month lateral XR and baseline ELXR were statistically similar for T1S-CL (26.04 vs 24.83; p=.542) and C2Slope (23.27 vs 22.87; p=.839). CONCLUSIONS Preoperative ELXR had a significant association with surgical approach and grade of osteotomy. The ELXR was statistically similar to the post-operative 3-month lateral XR and should be used to predict final cervical alignment. Obtaining ELXR is a critical alignment tool, and should be obtained as a part of the preoperative surgical plan. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.