124. Cervical deformity score: a composite alignment tool to optimize outcomes while mitigating complications

Abstract

<h3>BACKGROUND CONTEXT</h3> Cervical alignment and cervical deformity surgery are complex topics. Recently, a score inspired by work on thoracolumbar alignment was developed for cervical alignment (cervical deformity score, CDS). While this score was designed to predict early mechanical failures, its association with patient reported outcomes (PROM) remains unclear. <h3>PURPOSE</h3> Investigate the association between PROM, complications, and a newly described cervical deformity score. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospective multicenter database. <h3>PATIENT SAMPLE</h3> A total of 102 adult cervical deformity (CD) patients with at least 1 year follow-up. <h3>OUTCOME MEASURES</h3> NDI, neck pain, EQ5D, complication rates. <h3>Methods</h3> CD patients with baseline and 1-year follow-up were included. Postoperative CDS was constructed using offset from age-adjusted values: SVA [(age -55)*2+25], T1 Slope [(age -55)/4 + 28.7], and TS minus CL [cst: between 26.5 and 14.5°]. Points were assigned based on the offset from alignment targets and the CDS was the sum of the three individual scores. Association with patient-reported outcomes was investigated using Pearson's correlations. Comparison of CDS between patients with and without complication within 1-year was conducted. Logistical regression controlling for demographic and comorbidities was conducted to identify if CDS was an independent predictor of complications. <h3>Results</h3> A total of 102 patients met inclusion criteria (61.7yo±10, 66.7% F); 37.6% of them had a history of previous cervical surgery (16.7% previous ACDF, 11.7% previous posterior fusion). Preoperatively, they had elevated disability (NDI: 47.1±18.1), pain (NSR Neck: 6.6±2.5), myelopathy (mJOA: 13.6±2.7) and lower general health (EQ5D: 0.74±0.07). They also presented with an overall cervical kyphotic alignment (C2-C7: -6.3°±20.9), a moderate cervical anterior alignment (cSVA: 39mm±20; TS-CL: 37.9°±19.4) and a posterior global thoracolumbar alignment (SVA: -3mm±68). The median of number of levels fused was 7 [4-9], with 49% treated with a posterior approach and 30.4% with a combined approach; 83.2% received an osteotomy, 44.6% some posterior osteotomy, 16.8% grade 6 or 7. The mean operative time was 368min±208, median EBL was 525cc [200 1025], and LOS was 5 days [4 8]. At 1 year, patients improved significantly in terms of disability (NDI: 36.2±20.7, 60.8% reached MCID), pain (NSR: 4.1±2.9) and general health (EQ5D: 0.79±0.08) (all p<0.001). The cervical alignment significantly changed (C2-C7: 7.8±14.5m; cSVA: 34mm±15; TS-CL: 28.9°±12.6 all p <0.002), with a 1-year CDS of 1.68±2.46 (prctl [0 3.25]). There was a significant association between increased CDS and increased disability (r=0.273), pain (r=0.336) and lower general health (r=-0.283). Patient with a lower disability level (NDI<20) had a significantly lower CDS (0.71±2.3 vs 2.16±2.4 p<0.004). Patients without any complications before 1 year had a lower CDS (0.78±2.33 vs 2.18±2.40 p=0.005), as did patients without major complications (1.36±2.27 vs 2.50±.78 p=0.037). Deeper analysis revealed significant differences in terms of CDS for patients experiencing cardiopulmonary, instrumentation and radiographic complications (p<0.05). Multivariate analysis, controlling for age and comorbidities, show 1-year CDS to be a significant predictor of complication (p=0.002, OR=1.409). <h3>Conclusions</h3> With better outcomes and lower complication rate, maintaining a proportionate alignment postoperatively can result in superior outcomes following CD surgery. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.