Objective:To explore the mid-term clinical efficacy of nano-hydroxyapatite/polyamide66 cage(n-HA/PA66 cage)in anterior single-level and double-level cervical discectomy

decompression and fusion. Methods:A retrospective analysis was designed and conducted for 63 patients(45 cases were single-level

18 cases were double-level)who had a surgery of anterior cervical discectomy

n-HA/PA66 cage intervertebral fusion

titanium nail plate system internal fixation and had complete follow-up from July 2009 to May 2012. The surgery time

blood loss and complications of the operation were recorded. visual analogue scale scores

Japanese Orthopaedic Association Scores

neek disability index were adopted to assess clinical outcomes

radiology results including the height of intervertebral space

the angle of fused cervical lordosis

the fusion rate

et al. Results:All patients had 30-64 months’ follow-up

an average of 46.9 months. The mean surgery time and blood loss of the operation was 55.08 ml and 116.98 min respectively. Eleven cases occurred temporary dysphagia

2 cases happened neck hematoma

4 cases(6.35%) with cervical axial symptoms

2cases(3.17%)with C5 palsy. The VAS scores and JOA scores in single-level and double-level were improved at one week after the operation and at final follow-up compared with those of pre-operation(P <0.05). The NDI in single-level and double-level was improved at three months after the operation and at final follow-up compared with those of pre- operation(P <0.05). The height of intervertebral space and the angle of fused cervical lordosis in single-level and double-level were increased at one week

three months after the operation and at final follow-up compared with those of pre-operation(P <0.05). Three cases(2 in single-level and 1 in double-level) had subsidence of cage;the subsidence rate of cage was 4.76% at final follow-up. The fusion rate was 96.83% after operation. No other complication(such as tissue injury

infection

screw broken

et al)was observed after the operation. Conclusion:n-HA/PA66 cage can effectively reconstruct the bony structure of cervical

restore the angle of cervical lordosis and can maintain the height of intervertebral space

with favorable clinical curative effects. It can be an ideal pedicle-substitute material for cervical discectomy and fusion.