Anterior decompression and fusion with n-HA/PA66 composite artificial vertebral body and autogenous for the treatment of lower cervical spine injury

English Keywords:Nano-hydroxyapatite/polyamide 66  Cage  Autogenous bone  Lower cervical spine injury

English Abstract:

  【Abstract】 Objectives: To study clinical effect and difference between the n-HA/PA66 composite artificial vertebral body and the iliac bone autograft in anterior cervical decompression and fusion for treatment of lower cervical spine injury. Methods: From January 2009 to December 2013, the clinical data of 62 patients with lower cervical spine injury(All damage in the patients with single cervical vertebral fracture combined with cervical spinal cord injury) were retrospectively analyzed. 62 cases of lower cervical spine injury were treated with anterior cervical subtotal corpectomy and fixed by titanium locking plates. According to the bone-grafting materials, the patients were divided into 2 groups: 30 cases implanted with iliac bone autograft(group A) and 32 with n-HA/PA66 composite artificial vertebral body and autogenous bone(group B). Blood loss in operation, operative time, complications after operation, prosthesis subsidence rate after operation were compared between two groups. The patients was followed up by imaging evaluation and clinical curative effect evaluation． Segmental height and sagittal lordosis were measured by radiographs. Instrument displacement and fusion status were assessed by 3D-CT images. Neurological function was followed up by improvement rate of JOA score. Results: 62 patients were followed up for an average of 13±2.2 months(6-24 months). Blood loss in operation and operative time of group A were significantly higher than those of group B(P<0.05). Iliac bone infection were observed in 8 cases of group A; pain and numbness at donor site occurred in 16 cases of Group A. There was no rejection reaction in the two groups. The incidence of postoperative complications of the two groups were 80％ and 0％. There was significant difference in complications between 2 groups(χ2=17.12, P=0.00). The JOA score at 6 months after operation significantly improved when compared with preoperative score in 2 groups(P<0.05), but no significant difference was found between two groups at preoperation and 6 months after operation(P>0.05). The graft fusion rate was 100% in group A and 96.9% in group B(P=0.20). 1 case(3.1%) were noted prosthesis subsidence(loss of height≥3mm) at 6 months in group B, and two groups of prosthesis subsidence showed no significant difference. Both segmental height and lordosis improved significantly after surgery in two groups(P<0.05). There was no significant difference between segmental height and lordosis of the two groups at the corresponding time points. Conclusions: The n-HA/PA66 composite artificial vertebral body can not only restore and maintain the fusion segmental height and lordosis, but also promote the osseous fusion and profit the radiographic assessment after operation. And the n-HA/PA66 composite artificial vertebral body was the same fusion rate as iliac bone autograft. Therefore, n-HA/PA66 composite artificial vertebral body can be taken as an ideal graft for anterior cervical spine reconstructive surgery.