A study suggests that two years after scoliosis surgery in adults, the factors distinguishing between patients with the best and worst outcomes are primarily patient-related factors, including obesity and the presence of depression/anxiety. Christopher I Shaffrey told Global Spinal Congress 2011 delegates that none of the other factors assessed, including age, comorbidities, severity of deformity, operative parameters, or complications significantly distinguished between the best and worst outcomes.
In the presentation, Shaffrey, from the Department of Neurosurgery, University of Virginia, Charlottesville, USA, stated that current literature suggests surgical treatment can improve pain/disability for adults with symptomatic scoliosis but there is significant variability in outcomes. “On average, patients have a measurable improvement of pain and function after surgery. Predictors of marked improvement versus failure to improve have not been identified. The purpose of this study was to identify factors that distinguish between the best and worst outcomes in patients treated with surgery for adult scoliosis.”
He said that this was a secondary analysis of a prospective, multicentre spinal deformity database. Inclusion criteria included age 18–85, scoliosis (Cobb >20 degrees), and clinical health status measures, including the Oswestry Disability Index (ODI) and SRS-22, both preoperatively and at two years, and no prior instrumented spinal surgery. Univariate and multivariate analyses were used to assess for clinical, radiographic, and surgical factors distinguishing between patients with the best and worst outcomes based separately on changes in the ODI and SRS-22 from preoperative to two years follow-up. To minimise the floor effect of the ODI and ceiling effect of the SRS-22, only patients with at least moderate impairment of the ODI (>30) or SRS-22 (<4.0) were included in this analysis.
Two hundred and seventy one patients met inclusion criteria (245 females, mean age 50 years). Based on change in the ODI, 21 and 39 patients were defined as having the worst and best outcomes, respectively. Compared with patients with the best outcomes based on ODI, patients with the worst outcomes had significantly greater body mass index (BMI; 28 vs. 24, p=0.013) and had greater prevalence of depression/anxiety (48% vs. 21%, p=0.040). On multivariate analysis, with adjustment for baseline ODI, the ability of both parameters to distinguish between best and worst outcomes remained statistically significant (BMI: p=0.029; depression/anxiety: p=0.031). Based on change in SRS-22, 29 and 32 patients were defined as having the worst and best outcomes, respectively.
Compared with patients with the best outcomes based on SRS-22, patients with the worst outcomes had significantly greater prevalence of depression/anxiety (38% vs. 13%, p=0.036), and this remained statistically significant after adjusting for the effects of baseline SRS-22 score (depression/anxiety: p=0.004).
“None of the other factors assessed significantly distinguished between the best and worst outcomes based on either the ODI or SRS-22 including: patient age, baseline comorbidity index, baseline back or leg pain score, degenerative vs. idiopathic diagnosis, severity of deformity, surgical cases complexity (using operative time and blood loss as surrogates), and occurrence of complications.
“Collectively, this study suggests that the factors distinguishing between patients with the best and worst outcomes at two years following surgery for adult scoliosis are primarily patient related factors, including obesity and the presence of depression/anxiety; not patient age, patient comorbidities, severity of deformity, operative parameters, or the occurrence of complications,” Shaffrey concluded.