The Value Of Preoperative Imaging Evaluation In The Choice Of Surgical Mode Of Ossification Of Posterior Longitudinal

Objective:To observe the clinical efficacy of anterior and posterior operation for the treatment of OPLL,and explore the significanceof preoperative imaging evaluation in the choice of OPLL operation approach.Methods:Total of 60 patients with OPLL were included into study.Which involved 37 males and 23 females, were respectively decompressed from anterior or posterior approaches,the average age was 52.3 years (ranged,46-73years).patients were followed up for 2 to 6 years,2.7 years on average, lateral cervical spine X ray, flexion film had held out,CT scan,sagittal reconstruction, and MRI examinations were routinely taken preoperative.neurological function after operations according to the modified JOA scoring system, which was formulated by Japanese Orthopaedic Association,the early(1w) and final(2y) neural improvement rates(rate of the improved JOA score, RIS)were also calculated.The data Was evaculated by SPSS 19.0 analysis software, the difference was statisticalsignificance when P<0.05.Results:① Anterior approach decompression had better effect than posterior approach in treatment of OPLL with cervical curvature abnormality and the differences was statistically significant.②When the rate of spinal stenosis was less than 45%,anterior approach had better effect than posterior approach.when it was more than 45%, anterior approach had better effect than posterior approach in long-term follow up,but its results in short-term follow up was worse than posterior decompression, ③when the range of OPLL was no more than two segments,there was no significant difference between anterior and posterior approach in short-term,while anterior decompression had better effect in long-term follow up.when the OPLL was invoved more than 3 segments,anterior approach had better effect in short-term and long-term follow up.④In the continuous group, there was no significant difference between anterior and posterior approach in short-term follow up, but in long-term effect, anterior approach was better than posterior approach.In the segment OPLL group, there was no significant difference between anterior and posterior approach.In the mixed group, posterior decompression had better effect than anterior approach in short-term follow up,but its long-term effects was not better than anterior approach.In the solitary OPLL group, anterior approach had better effect than posterior approach in short-term and long-term follow up. ⑤ In the ISI group,there was no significant difference between anterior and posterior approach in short-term effect,but in long-term effect,anterior approach had better effect and RIS.In the group without ISI,posterior approach had better effect than anterior in short-term,but anterior decompression had better effect in long-term follow up.Conclusions: ① The cervical curvature,ranges and types of OPLL,rate of spinal stenosis,increased signal density of spinal cord and other factors can influence the outcomes of OPLL operations.therefore,which should become the important part of preoperative evaluation,and be used to guide the surgery strategies of OPLL.② Anterior decompression can obtain satisfactory recovery of nerve function and keep for a long time apart from ossification above C2,but for patients with sever clinical symptoms,ossification invoved 3 or more segments and spinal stenosis was more than 45%,take posterior decompression at first may be more effective and safer.③ To patients which cervical curvature was straighten or kyphosis should choose anterior decompress operations to recover the normal cervical curvature and reconstruct the cervical stability,because of the limited decompress space and poor long-term efficacy of posterior operations.