Advances in Cervical Artificial Disc Replacement for Cervical Spondylosis

Anterior cervical decompression and fusion(ACDF)treatment for cervical spondylosis has been more than half a century,and achieved good clinical results.However,with the continuous extension of follow-up time,the fusion segment-associated postoperative complications emerged gradually.Reserved cervical stability and activity,the concept of non-fusion was born.As a non-fusion technique,cervical artificial disc replacement(CADR)developed rapidly.With the continuous development of artificial prosthesis materials and design concepts,and specification and proficiency of surgical procedures,CADR has achieved better short and mid-term clinical efficacy than ACDF.Compared with ACDF,the main advantages of CADR are that the postoperative recovery is quick,the activity and stability of cervical vertebra are maintained,the height of cervical intervertebral space is restored,and the stress of adjacent segments and the rate of surgical renovation are reduced.In clinical work,as an emerging technology,CADR requires spine surgeons to control the surgical indications,contraindications,and patients'conditions strictly.This article reviews the research progress of CADR in order to provide new ideas for clinical treatment of cervical spondylosis.

Outcomes of cervical degenerative disc disease treated by anterior cervical discectomy and fusion with self-locking fusion cage

BACKGROUND Cervical degenerative disc(CDD)disease is a common type of spondylosis.Although anterior cervical discectomy and fusion(ACDF)is the preferred treatment for CDD disease,internal fixation with a titanium plate may cause various complications.The invention of the ACDF with a self-locking fusion cage(ROI-C)has effectively decreased the incidence of postoperative complications.AIM To observe the outcomes of CDD disease treated by ACDF with a ROI-C.METHODS Ninety patients with CDD disease treated at our hospital from March 2019 to March 2021 were included.They were divided into two groups(control group and observation group,n=45 in each)using a random number table.Patients in the control group received ACDF plus internal fixation with a titanium plate.Those in the observation group received ACDF+ROI-C placement.The two groups of patients were compared in terms of surgical parameters,pain,cervical spine function,range of motion,and complications.RESULTS The two groups of patients showed no significant differences in surgical time,blood loss,drainage volume,and length of hospital stay(P>0.05).No significant differences in the visual analogue scale(VAS),Japanese Orthopedic Association(JOA),and neck disability index(NDI)scores were observed between the two groups before surgery(P>0.05).The VAS and NDI scores in the observation group were considerably lower than those in the control group after surgery;however,the JOA scores in the observation group were significantly higher than those in the control group(P<0.05).No significant differences were observed in cervical disc height and the range of motion of the superior or inferior adjacent vertebrae between the two groups before surgery(P>0.05).The disc height in the observation group was larger than that in the control group after surgery.The range of motion of both the superior and inferior adjacent vertebrae was significantly smaller in the observation group than in the control group(P<0.05).The incidence of complications was only 2.22% in the observation group compared to 15.56% in the control group,and the difference was statistically significant(P<0.05).CONCLUSION Cervical spine function restoration was better with ROI-C with internal fixation in ACDF than with conventional titanium plates in ACDF for CDD disease.

Delayed massive cerebral infarction after perioperative period of anterior cervical discectomy and fusion:A case report

BACKGROUND Cerebral infarction is an extremely rare postoperative complication of anterior cervical discectomy and fusion(ACDF),particularly in the delayed setting.We present a case who had a sudden stroke on day 18 after surgery.By sharing our experience with this case,we hope to provide new information about stroke after anterior cervical surgery.CASE SUMMARY We present the case of a 61-year-old man with more than 20 years of hypertension and 14 years of coronary heart disease who had suffered a stroke 11 years ago.The patient was admitted for a multiple ACDF due to symptoms of cervical spondylotic myelopathy and had a sudden stroke on day 18 after surgery.Imaging findings showed a large-area infarct of his left cerebral hemisphere and thrombosis in his left common carotid artery.With the consent of his family,the thrombus was removed and a vascular stent was implanted through an interventional operation.Forty days later,the patient was transferred to a rehabilitation hospital for further treatment.He had normal consciousness but slurred speech at the 1-year follow-up evaluation.The motor and sensory functions of his hemiplegic limbs partially recovered.CONCLUSION This case illustrated that a postoperative stroke related to anterior cervical surgery may be attributed to prolonged carotid retraction and might have a long silent period.Preventive measures include careful preoperative and postoperative examination for high-risk patients as well as gentle and intermittent retraction of carotid artery sheath during operation.

Mid-term outcomes of Bryan cervical disc arthroplasty versus anterior cervical discectomy and fusion for cervical spondylopathy

Objective To compare the clinical outcomes of Bryan disc replacement with anterior cervical discectomy and fusion (ACDF) in patients with cervical spondylopathy. Methods Sixteen patients underwent Bryan cervicaldisc replacement (A group) ,and

Cervical Disc Arthroplasty Combined with Interbody Fusion for the Treatment of Cervical Myelopathy with Diffuse Idiopathic Skeletal Hyperostosis： A Case Report

Diftuse idiopathic skeletal hyperostosis （DISHL also known as Forestier＇s disease, was originally reported by Forestier and Rotes-Querol in 1950. It is a common but underdiagnosed skeletal disease characterized by massive ossification of the anterior longitudinal ligament of several vertebral bodies. The most common symptom of cervical DISH is dysphagia due to mechanical compression of the esophagus. Reports of cervical myelopathy associated with DISH are rare. Here, we present a case describing a DISH patient with cervical myelopathy who was effectively treated by a carefully designed surgical procedure.

Adjacent segment disease after anterior cervical decompression and fusion： analysis of risk factors on X-ray and magnetic resonance imaging

Background Adjacent segment disease （ASD） is common after cervical fusion.The aim of this study was to evaluate the risk factors for ASD on X-ray and magnetic resonance imaging （MRI）.Methods Patients included in this study had received revision surgeries after developing symptomatic ASD following anterior decompression and fusion.A control group that had not developed ASD was matched 1：1 by follow-up time and fusion segments.Plate-to-disc distances （PDDs）,developmental cervical canal stenosis on X-ray,cervical disc degeneration grading,and cervical disc bulge impingements on preoperative MRI were measured and compared between the ASD group and the control group.Results Thirty-four patients with complete radiographic data were included in the ASD group.The causative segments of ASD included nine cases of C3-4,18 cases of C4-5,three cases of C5-6,and four cases of C6-7.The ASD occurred at the upper adjacent segments in 26 patients and at the lower adjacent segments in eight patients.PDD distributions were similar between the ASD group and the control group.Developmental cervical canal stenosis was a risk factor for ASD,with an odd ratio value of 2.88.Preoperative cervical disc degenerations on MRI were similar between the ASD group and the control group.In the upper-level ASD group,the disc bulge impingement was （19.7±9.7）％,which was significantly higher than that of the control group of （11.8±4.8）％.Conclusions ASD was more likely to develop above the index level of fusion.Developmental cervical canal stenosis and greater disc bulge impingement may be risk factors for the development of ASD.

A critical review on the biomechanical study of cervical interbody fusion cage

Anterior Cervical Discectomy and Fusion(ACDF)is the preferred surgical method for the treatment of severe cervical degenerative disc disease with radiculopathy or myelopathy,of which the objectives are to restore the normal height of intervertebral space and cervical lordosis through the implantation of cervical interbody fusion cage.The biomechanical performance of a cervical interbody fusion cage,which plays a significant role in achieving the goals of ACDF,is influenced by multiple factors.In this paper,various studies focusing on the biomechanical performance of cervical interbody fusion cage are reviewed.Furthermore,the research methods,biomechanical evaluation parameters and data analysis methods of these research are analyzed in order to obtain a comprehensive understanding of the progress and limitations of research in this field.Although great progress has been made to clarify the biomechanical behaviors of cervical interbody fusion cage,there is still controversy regarding the issues such as the relative contribution of multiple factors to the performance of cage,the interactions among these factors,as well as whether the effects of factors change with the process of intervertebral osseointegration and so on.Thus,investigations are still needed to improve the comprehension of cervical interbody fusion cage biomechanically.

Dysphagia in a patient with ankylosing spondylitis:A case report

BACKGROUND Ankylosing spondylitis(AS)is a systematic and rheumatic disease,which causes multiple symptoms.However,dysphagia due to the formation of a giant anterior cervical osteophyte is rare in patients with AS.CASE SUMMARY We present the case of a 65-year-old male patient who was diagnosed with AS and visited the hospital with a complaint of progressive dysphagia.The appropriate imaging examinations indicated that a giant anterior cervical osteophyte at C3-4 caused esophageal compression,which led to dysphagia.An operation for resection was performed without complications.CONCLUSION This case demonstrates that a large cervical osteophyte may be the cause of dysphagia in patients with AS,and early accurate diagnosis and surgical treatment are very important for the improvement of symptoms.Anterior cervical discectomy and fusion are extremely effective and should be taken into consideration.

Comparison of the anterior and posterior approach in treating four-level cervical spondylotic myelopathy

Background:The optimal surgical approach for four-level cervical spondylotic myelopathy remains controversial.The purpose of this study was to compare clinical and radiological outcomes and complications between the anterior and posterior approaches for four-level cervical spondylotic myelopathy.Methods:A total of 19 patients underwent anterior decompression and fusion and 25 patients underwent posterior laminoplasty and instrumentation in this study.Perioperative information,intraoperative blood loss,clinical and radiological outcomes,and complications were recorded.Japanese Orthopedic Association(JOA)score,36-item short form survey(SF-36)score and cervical alignment were assessed.Results:There were no significant differences in JOA scores between the anterior and posterior group preoperatively(11.6±1.6 vs.12.1±1.5),immediately postoperatively(14.4±1.1 vs.13.8±1.3),or at the last follow-up(14.6±1.0 vs.14.2±1.1)(P>0.05).The JOA scores significantly improved immediately postoperatively and at the last follow-up in both groups compared with their preoperative values.The recovery rate was significantly higher in the anterior group both immediately postoperatively and at the last follow-up.The SF-36 score was significantly higher in the anterior group at the last follow-up compared with the preoperative value(69.4 vs.61.7).Imaging revealed that there was no significant difference in the Cobb angle at C2-C7 between the two groups preoperatively(-2.0°±7.3°vs.-1.4°±7.5°).The Cobb angle significantly improved immediately postoperatively(12.3°±4.2°vs.9.2°±3.6°)and at the last follow-up(12.4°±3.5°vs.9.0°±2.6°)in both groups compared with their preoperative values(P=0.00).Three patients had temporary dysphagia in the anterior group and four patients had persistent axial symptoms in the posterior group.Conclusions:Both the anterior and posterior approaches were effective in treating four-level cervical spondylotic myelopathy in terms of neurological clinical outcomes and radiological features.However,the JOA score recovery rate and SF-36 score in the anterior group were significantly higher.Persistent axial pain could be a major concern when undertaking the posterior approach.