Risk factors for complications after fusion in the treatment of adult degenerative scoliosis

English Keywords:Adult spinal deformity  Degenerative scoliosis  Medical complications  Risk factors

English Abstract:

  【Abstract】 Objectives: To analyze the risk factors for medical complications in adult patients with adult degenerative scoliosis(ADS) who underwent long fusion. Methods: This was a retrospective study that analyzed adult degeneration scoliosis patients who underwent long fusion with posterior pedicle screw fixation in our hospital between January 2012 and January 2016. All patients were divided into no medical complications group(n=58) and medical complications group(n=24). The radiographic parameters including Cobb′s angle, PI-LL and SVA were compared between the two groups at preoperation and the final follow-up. Internal medical complications in this study included intra- and perioperative complications such as deep and superficial wound infection, pneumonia, sepsis, nerve root injury with weakness, neuropathy or sensory deficit, pain(radiculopathy), peripheral nerve palsy, congestive heart failure, deep vein thrombosis, myocardial infarction, pleural effusion, arrhythmia, coagulopathy, pneumothorax, gastrointestinal complications and renal dysfunction. Potential risk factors were identified by using univariate analysis. Multivariate Logistics regression was used to analyze the independent risk factors for medical complications. The clinical functional scores were assessed by using the Oswestry disability index(ODI), Japanese Orthopaedic Association(JOA) scores and visual analogue scale(VAS) at preoperation, 4 weeks, 52 weeks and 104 weeks of postoperation. Functional scores were tested by using multivariate repeated measured mixed models. Results: Eighty-two ADS patients who underwent long fusion were included. The incidence of patients with medical complications was 29.3%. The incidence of hypertension, diabetes and anemia were 30.5%, 20.7% and 9.8%, respectively. Among the postoperative complications, 14(17.1%) cases were infected, 9(11.0%) cases were complicated with cardiopulmonary dysfunction, 11(13.4%) cases were complicated with gastrointestinal disease, and 1 patient was with abnormal renal function(1.2%). The incidence of cerebrospinal fluid leakage in the no medical complications group was significantly lower than that in the medical complications group(19.0% vs. 54.2%, P=0.001). There were no significant differences in Cobb angle, PI-LL and SVA between the two groups at preoperation(P＞0.05). Cobb angle, PI-LL and SVA used in the radiographic parameters of the two groups were not significantly different at postoperation(P＞0.05). Independent predictors identified on multivariate Logistics regression modeling included BMI(OR 1.127, P=0.011), smoking(OR 3.15, P=0.032), length of hospital stay(OR 1.16, P=0.047), and duration of symptoms(OR 1.33, P=0.025). Despite experiencing medical complications, patients presented significant improvements at the final follow-up clinical functional scores ODI(P=0.0001), JOA(P=0.0001) and VAS(P=0.0001) after operation. However, there was no statistically significant difference in clinical scores between the two groups. Conclusions: Risk factors of postoperative medical complications after surgery of ADS include diabetes, smoking and hospital stay.