Efficacy Of The Nano-hydroxyapatite/Polyamide66Strut For Reconstruction Of Cervical Stability

Background and objectives: Anterior cervical corpectomy andfusion (ACCF) was an optimal surgical technique for multilevel cervicalspondylotic myelopathy (MCSM). Comparing with the anterior cervicaldiscectomy and fusion (ACDF), ACCF can remove the prolapsed discsand part of vertebtrae directly which ensure the decompression more safe.At meanwhile, it is important to choose appropriate strut forreconstruction of anterior cervical column after corpectomy. In presentstudy, we conducted the mid-and long-term follow-up of patients withMSCM who underwent the n-HA/PA66strut for cervical reconstruction into explore a safe and reliable strut for ACCF.Methods: Between May2006and July2007, a series of48consecutive patients (27males and21females) with MCSM whounderwent ACCF with the n-HA/PA66strut in our department wereretrospectively evaluated, The Japanese Orthopedic Association (JOA)score was used for assessed the neurologic status and visual analoguescale (VAS) was used for grading the arm-neck pain, the recovery rate ofJOA score was used for assessed the improvement of neurologic status. The bony fusion status, the loss of the fused segmental height, theincidence of strut subsidence and improvement of cervical lordosis wereevaluated by radiographic outcomes.Results：Of all the48patients,1-level corpectomy and fusion wasperformed in37patients and2-level corpectomy was performed in11patients. With a mean follow-up of79.4±6.3months. The overall meanJOA score was12.5±1.8preoperatively and significantly improved to15.3±1.2at last follow-up,（P<0.001）.Neck-arm pain was assessed byVAS, The overall mean VAS was4.6±1.6preoperatively andsignificantly decreased to1.2±0.9at last follow-up,（P<0.001），and therecovery rate was63.2±21.5%at last follow-up. For the radiographicoutcomes, The bony fusion was97.9%at last follow-up. The mean fusedsegmental height was56.3±9.4mm preoperatively and significantlyimproved to64.3±9.5mm postoperatively, and maintained at62.6±9.4mm at last follow-up, The mean C2-C7Cobb angle was9.7±6.1°preoperatively and improved to13.1±5.3°postoperatively, and was11.1±5.4°at last follow-up. No significant differences were detected in thefusion rate, loss of fused segmental height or subsidence rate between1-level ACCF and2-level ACCF.Conclusion：1. The utilization of n-HA/PA66strut for cervicalreconstruction after anterior cervical decompression is an appropriate technique for MCSM, long-term outcomes are satisfied.2. Satisfactory bony fusion rate and acceptable strut subsidence rate wereachieved when using n-HA/PA66strut for ACCF. At long-term follow-up,the fused segmental height and cervical lordosis were maintained; theinternal fixation related complications were low.3. When using the n-HA/PA66strut for ACCF, the increase of fusedsegment would not lead to the decrease of the bony fusion rate, more lossof fused segmental height or rise in incidence of strut subsidence.4. Worse preoperative neurological status was highly predictive of apoorer postoperative recovery. Early decompression is better for theneurological recovery.