[Clinical observation and evaluation of reasons for pseudarthrosis after anterior cervical fusion]

To explore the causes of pseudarthrosis and evaluate the clinical neurological function and neck subaxial symptoms after anterior cervical fusion.

A total of 412 patients were followed up with an average of 5.4 years. The bone mineral density, bone graft trimming and placement, management of endplate, smoking and neck support fixation time were observed. Japanese Orthopedic Association (JOA) score was used to evaluate the changes of neurological functions and clinical outcomes. Visual analog scale (VAS) score was used to evaluate the neck subaxial symptoms. And pseudarthrosis was examined by flexion-extension radiography. SPSS statistical software 13.0 was used to evaluate the differences of JOA and VAS scores between pseudarthrosis and control groups.

Among them, 37 cases of pseudarthrosis were observed. There were osteoporosis (n = 30 vs n = 119), cartilage end-plate punctuate hemorrhage (n = 18 vs n = 340), 25 and 43 cases with ineffective cervical external fixation (n = 25 vs n = 43) and smoking (n = 26 vs n = 87) in pseudarthrosis and fusion groups respectively. Significant differences existed in the above-mentioned indices between two groups. However, no significant difference existed in bone graft shape between two groups. There were significant differences in JOA and VAS scores between two groups.

The causes of pseudarthrosis included decreased bone density, osteoporosis, over-curette of endplate, shortness of neck support fixation time and smoking. And pseudarthrosis may influence the long-term recovery of neurological functions or it is correlated significantly with neck symptoms.