P118. Pelvic fixation improves coronal balance, decreases pelvic obliquity, but is not essential in neuromuscular scoliosis (NMS)

Abstract

BACKGROUND CONTEXT Non-ambulatory NMS patients are typically fused to the pelvis to augment fixation, prevent loss of correction and improve seating balance. However, pelvic fixation extends the length of surgery, increases EBL and may increase pain. PURPOSE This study aims to evaluate the radiographic outcomes after PSF with all pedicle screws in NMS fixated (FP) and not fixated at the pelvis (NFP). STUDY DESIGN/SETTING Retrospective and Prospective Review. PATIENT SAMPLE Ambulatory and non-ambulatory neuromuscular patients undergoing spinal deformity correction at one institution. OUTCOME MEASURES Preoperative and postoperative radiographic parameters and intraoperative clinical measures (estimated blood loss, operative time). METHODS Radiographic measurements, OR parameters and demographics were recorded for neuromuscular surgeries between 2006-2016. Patients were divided into NFP and FP. Median values and Wilcoxon rank sum tests were used. Subanalysis was performed for patients with preoperative PO 20°. RESULTS There were 91 patients; 63 were non-ambulatory. Between NFP (n=54) and FP (n=37), preop Cobb (p=0.215), PO (p=0.158), and decompensation (p=0.247) were similar. Both had similar final Cobb (p=0.146) and PO (p=0.162), but NFP had significant coronal imbalance (35.8 vs 14.6, p 20, patients had similar preop PO (p=0.545) and decompensation (p=0.075). NFP had higher final PO (p=0.123) and significantly higher decompensation (135.4 vs 25.2, p=0.008). The change in PO (p=0.298) and decompensation (p=0.616) from postop to final was similar. CONCLUSIONS NFP with preop PO>20 had significant coronal imbalance and PO at final follow-up. Change in PO and coronal balance over time was similar between the two groups in less severe PO. PF achieves better coronal and PO correction. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.