Clinical Study On The Feasibility,Efficacy And Complications Of Computer-Assisted Design Precise Cervical Intervertebral Resection Of OPLL

BackgroundCervical ossification of the posterior longitudinal ligament(COPLL)is defined as ectopic ossification of the cervical posterior longitudinal ligament which compress the spinal cord and nerve root,inducing related clinical symptoms and signs.Since the occult onset and low specificity,it is commonly neglected by patients,which results in the missing of the best opportunity for operation and the rapid decline of muscle strength or even paralysis in a short period of time.The pathological mechanism of COPLL is heterotopic ossification of posterior longitudinal ligament.Its risk factors include genetic factors and non-genetic elements.At present,the susceptibility genes of OPLL and other risk factors that may lead to OPLL have been found and discussed,however the exact pathophysiological mechanism has not been clearly explained.Surgical treatment of COPLL is the most direct and effective way to decompress the spinal cord.However,as the segments involved in ossification are often long and often grow by leaps and bounds,the design of surgical segments is difficult.Since the ossified ligament is hard and causes severe spinal cord compression,it is common to cause massive bleeding during operation,high risks,more blood loss of patients,more postoperative complications,incompletely ossification removing,and the need for long-term postoperative follow-up.The choice of surgical methods is determined by the involved ossified segments,the degree of the spinal cord compression,the surgical tolerance of the patients,the surgical skill and habits of surgeons.At present,the most common clinical choice of surgery is anterior direct decompression or posterior indirect decompression,meanwhile,the postoperative complications of either choice still need exploring and vigilance,which is not only the patients’most concern matter causing anxiety before operation but also the clinicians’most consideration of the cautious choice when evaluating patients’possible prognosis and complications.Our group adopts computer-aided design precise cervical intervertebral resection of OPLL to compress the spinal cord.The operation diagram is drawn by CAD(Computer Aided Design)before operation.The feasibility of operation is analyzed automatically by Python language coding.The optimal resection range is calculated.The real-time interaction is realized through Web page.According to the measured results,the intervertebral space is decompressed effectively,and the ossified ligament is removed directly,which obtains satisfactory clinical effect.In order to furtherly analyze and evaluate the effect of computer-assisted design precise cervical intervertebral resection of OPLL operation and postoperative complications in patients with COPLL,we analyzed the feasibility of computer-assisted design precise cervical intervertebral resection of OPLL Through medium-term follow-up,the improvement rate of COPLL classification,JOA and NDI score of pre-operation and post-operation,cervical curvature improvement rate,dysphagia,adjacent intervertebral disc degeneration,postoperative wound hematoma,wound infection,cerebrospinal fluid leakage and spinal cord function improvement were compared with ACCF operation,to explore the medium-term efficacy and imaging changes of computer-assisted design precise cervical intervertebral resection of OPLL,aiming to more comprehensive awareness and evaluation of the efficacy,safety and applicability of this surgery.PART Ⅰ Feasibility,optimal plan analysis and visual interaction of precise cervical intervertebral resection of OPLL based on CAD,Python and other computer-assisted design methodsPurposeThis section expounds the research background,theoretical basis,research process and clinical significance of computer-aided design precise cervical intervertebral resection of OPLL before operation,and verifies the reliability and matching degree of this technique through clinical cases and then expounds the clinical significance of this technique in accurate,minimally invasive and individualized treatment of OPLL and the advanced research direction.MethodsThe principle and construction process of constructing two-dimensional surgical model based on CAD technology,automatic calculation and analysis of algorithm logic based on Excel software,and real-time interaction between data and graphics through Web browser using Python language program system were described respectively.By collecting the preoperative data of OPLL patients and comparing the best operation scheme obtained by computer automatic analysis and postoperative imaging data,the clinical matching and reliability of this technique were discussed.SPSS23.0 was used for data processing and statistical analysis.The research materials involved in this study were qualitative data and quantitative data.The quantitative data included the height of cervical vertebra,sagittal diameter of vertebral body,distance of intervertebral space,OPLL height of posterior edge of cervical vertebra,sagittal diameter of cervical bone graft fusion plane,V-shaped resection and decompression angle,sagittal diameter of cervical bone graft fusion plane and percentage of sagittal diameter of vertebral body on anterior-posterior and lateral cervical X-ray and three-dimensional reconstruction via CT.The qualitative data included the distribution and type of OPLL segments.ResultsBy referring to the relevant parameters of Chinese cervical vertebra anatomy and using CAD technology,the two-dimensional surgical model can be drawn quickly and accurately.The feasibility analysis of data and automatic calculation of optimal operation scheme can be realized by collecting and analyzing the relevant data of Chinese cervical vertebrae anatomy and importing Excel software to construct the algorithm logic.Based on the former progress,the Python programming language was used for data processing and operation,then the feasibility of the operation was analyzed directly,and the optimal operation scheme was solved automatically.The real-time presentation of data and graphics was realized through the Web browser.The data has been preliminarily tested by clinical cases,which shows high reliability and satisfactory matching degree.ConclusionAccording to the practical test,the schematic diagram of the operation was drawn by CAD technology before the treatment of OPLL patients,the feasibility analysis of the operation was automatically calculated,the optimal resection range was determined by Python programming,and the visual interactive interface was realized through Web,which provided intuitive,accurate and clear model reference and rapid theoretical basis for clinical practice.During the operation,the minimally invasive concept was used to avoid the unnecessary removal of cervical vertebrae,so that the incidence of postoperative complications was reduced,and the postoperative interbody fusion was satisfied.In the future,based on the patient imaging Dicom data,using 3D rendering software to build OPLL accurate 3D visualization model combined with Python language to achieve automatic data entry and accurate measurement and analysis,as well as the research and development of related surgical instruments,is the direction that need to be furtherly explored.PART Ⅱ Clinical study on the efficacy and complications of precise cervical intervertebral resection of OPLL by computer-aided designPurposeThrough retrospective case control study,we compared computer-assisted design precise cervical intervertebral resection of OPLL and ACCF in the treatment of OPLL to explore the clinical efficacy and postoperative complications of two different surgical methods in the treatment of OPLL,and to explore the efficacy,safety,and postoperative complications of computer-assisted design precise cervical intervertebral resection of OPLL.MethodsSPSS23.0 was used for data processing and statistical analysis.The research materials involved in this study are qualitative data and quantitative data.The quantitative data included the measurement of cervical kyphosis angle,retropharyngeal space,retrotracheal space,dynamic stenosis of cervical spinal canal,Pavlov ratio,preoperative height of operative segment and preoperative range of motion in flexion and extension via AP,lateral and dynamic lateral X-ray,the occupancy of ossified ligament invertebral canal(maximum thickness of ossification/anterior-posterior diameter of spinal canal)was measured on axial cervical CT scan and three-dimensional reconstruction.The postoperative cervical kyphosis angle,retropharyngeal space,retrotracheal space,JOA,VAS and EAT-10 scores were recorded.The qualitative data included the distribution and type of OPLL segments.The quantitative data were described by mean±standard deviation.Bilateral Student’s test was used to compare the data between the two groups.The qualitative data were analyzed byχ~2test,and p<0.05 was defined as statistical difference.ResultsIn this study,a total of 112 patients who underwent anterior cervical approach for OPLL were followed up for at least 2 years,including 67 patients with computer-assisted design precise cervical intervertebral resection of OPLL(hereinafter called‘Precision resection group’)and 45 patients with ACCF.There was no significant difference in sex,age,medical history,BMI and other basic data between the two groups.The results showed that the operation time and intraoperative blood loss in Precision resection group were significantly less than those in ACCF group(p<0.05).During the last follow-up,there was no significant difference in JOA score and improvement rate,postoperative VAS score and improvement,postoperative NDI index and improvement between the two groups.The recovery of cervical kyphosis angle and cervical height in Precision resection group was better than that in ACCF group(p<0.05).There was no significant difference in postoperative cervical range of motion(ROM)between the two groups.No spinal cord or nerve injury was found in either group.The incidence of postoperative dysphagia and EAT-10 score Precision resection group in the two groups were significantly lower than those in the ACCF group(p<0.05).There was no significant difference in other complications between the two groups.ConclusionThe follow-up study showed that both computer-assisted design precise cervical intervertebral resection of OPLL and ACCF could achieve better clinical effects in patients with OPLL,and there was no significant difference in the improvement rate of postoperative JOA between the two groups.In Precision resection group,based on computer-assisted automatic analysis of surgical feasibility and formulation of surgical plan,OPLL compression was improved by direct decompression of intervertebral space and V-shaped decompression.Cervical MRI and CT three-dimensional reconstruction of postoperative follow-up showed that precise cervical intervertebral resection of OPLL could obtain satisfactory decompression space,and the postoperative recovery of intervertebral space height and improvement of cervical kyphosis angle were better than ACCF,and the postoperative fusion of intervertebral space implants was satisfactory.Precision resection group showed less intraoperative bleeding,shorter operation time and lower incidence of postoperative dysphagia.During the 2-year follow-up,the implants in all patients after precise cervical intervertebral resection of OPLL fused well,and there was no obvious osteophyte hyperplasia and ossification progress of the posterior longitudinal ligament.However,the straightening of the upper segment of the operation is a problem that we need to pay more attention to,which may accelerate the adjacent segment disc degeneration and lead to the occurrence of adjacent segmental disease(ASD),which is also the direction that need further exploration.