Long-term Efficacy Of Anterior Decomposition And Fusion With Hydroxyapatite/polyamide 66 Bionic Bone In Treatment Of Cervical Spondylotic Myelopathy

BackgroundCervical spondylotic myelopathy（cevical spondylotic myelopathy,CSM）is due to cervical disc degeneration with or without adjacent tissue degeneration（posterior vertebral spur,posterior longitudinal ligament ossification,ligamentum flavum hypertrophy or calcification,etc.）,resulting in compression of spinal cord,resulting in corresponding^[1].Since the report of anterior cervical surgery for the first time since the Smith and Robinson,the treatment of anterior cervical decompression and interbody fusion has been widely applied to cervical degeneration,for the 2 segment of the spinal cord anterior compression of cervical spondylosis patients,the clinical use of anterior cervical corpectomy and interbody fusion（ACCF）can get good results.In order to achieve a better reconstruction effect,the anterior bone graft fusion material has experienced autogenous iliac bone,allograft bone,titanium mesh and so on,but there are some shortcomings.Nano hydroxyapatite/polyamide 66（n-HA/PA66）bionic bone column is Sichuan guona technology limited production,the material is a hollow cylinder,a diameter of 11 mm,13 mm,7 mm,diameter 5 18³5,length mm,the lateral wall is provided with a plurality of 3 mm hole and both ends of 1 mm*0.3mm channel slot.In the current literature on nano hydroxyapatite/polyamide 66 bone in anterior cervical decompression and fusion in treatment of cervical spondylotic myelopathy with short-term and medium-term outcomes more,we found that nano hydroxyapatite/polyamide 66 bone is a new type of bone graft materia,it has the compatibility,biological activity and bone conductivity,good biological,which is regarded as a ideal human bone repair material,short-term and medium-term follow-up is satisfactory;however,there are few reports on the long-term follow-up effect for more than 5 years.ObjectiveTo assess the long-term effectiveness of anterior cervical corpectomy and fusion with nano-hydroxyapatite/polyamide 66（n-HA/PA66）bionic bone in treatment of cervical spondylotic myelopathy.MethodsThe clinical datas of 55 patients with cervical spondylotic myelopathy treated by anterior cervical vertebrotomy,nano hydroxyapatite/polyamide 66（n-HA/PA66）biomimetic bone graft and fusion were retrospectively analyzed in the first Affiliated Hospital of Zhengzhou University from January 2008 to December-2013.There were35 males and 20 females,aged 39-72 years,with an average of 53.6 years.The course of disease was 2-14 months,with an average of 7 months.All patients underwent preoperative cervical lateral flexion extension,lateral cervical DR,64 slice spiral CT scan and 3D reconstruction,cervical MRI scan;postoperative cervical anteroposterior and lateral DR,short-term postoperative and final follow-up underwent cervical anteroposterior and lateral,hyperextension the flexor side DR of cervical vertebra,64slice spiral CT scan and 3D reconstruction.Preoperative,immediate postoperative,short term postoperative and final follow-up were recorded the following indicators:1.Japan Department of orthopedics Association（JOA）score 2.Visual analogue scale（VAS）3.Neck disability index（NDI）4.C2-7 Cobb angle 5.Fusion segment height and sinking rate 6.Fusion rate of bone graft fracture 7.Bionic bone and screw dislocation,dislocation 8.Operation complications.The results were analyzed by statistical method and SPSS software.ResultsN-HA/PA66 bionic bone can effectively restore and maintain the physiological curvature of cervical spine and the height of the fusion segment,improve the clinical symptoms of patients and promote the bone graft fusion,the long-term effect is satisfactory,and it is an ideal new bone graft material.However,there are still some complications such as bionic bone transposition、bionic bone sinking、screw dislocation.Therefore,this biological composite still needs to be optimized in order to achieve more satisfactory clinical efficacy.