Surgical strategy used in multilevel cervical disc replacement and cervical hybrid surgery:Four case reports

BACKGROUND Multilevel artificial cervical disc replacement and anterior hybrid surgery have been introduced as reliable treatments for multilevel cervical degenerative disc disease.Surgical techniques are important for resolving patients’symptoms and maintaining the normal functioning of cervical implants.However,the use of inappropriate surgical strategies could lead to complications such as implant migration and neurological deficit.In this paper,we summarize our surgical strategies used in multilevel cervical disc replacement and hybrid surgery into five major notes.CASE SUMMARY We share the key notes and our surgical procedures in the form of four typical case presentations.All patients were diagnosed with cervical degenerative disc disease with myelopathy or radiculopathy and needed multilevel cervical spine surgery.The first case demonstrated that index levels indicating the presence of highly serious spinal cord compression required a prioritized decompression.The second case demonstrated that the disc replacement should be performed before fusion in cervical hybrid surgery.The third and forth cases demonstrated that a top-down implantation sequence was needed in continuous two-level cervical disc replacement.The symptoms of all patients were significantly relieved after surgery.CONCLUSION We hope that our surgical strategies can help improve the performance and outcomes of multilevel cervical spine surgery.

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.

Incidence and risk factors analysis of heterotopic ossification after cervical disc replacement

Background Cervical disc replacement （CDR） as a substitute for traditional fusion surgery has been widely used in treating degenerative cervical disc diseases.The objectives of this study were to assess the clinical and radiological findings for patients with heterotopic ossification （HO） following CDR and to detect the risk factors of HO after CDR.Methods A total of 125 patients with symptomatic cervical single-or double-level disc diseases,who underwent CDR procedure with Discover prosthesis in Department of Spine Surgery,Changzheng Orthopedics Hospital from March 2009 to March 2011,were enrolled in this retrospective study.Occurrence of HO was defined by the McAfee classification on cervical lateral X-rays in this study.Prosthesis vertebral ratio （PVR） was used to determine the matching degree between the cervical disc prosthesis and cervical vertebra.Logistic regression analyses were performed to determine the risk factors of HO.Variables evaluated for their association with HO occurrence included age,gender,high-intensity signal in spinal cord,preoperative range of motion （ROM）,postoperative ROM,operation level number,and PVR.Results Mean follow-up time was （26.4±5.8） months.All the patients had significant symptoms and neurological function improvements during the follow-up period.The ROM of the operated segment from the preoperative period to the last follow-up was relatively well maintained.The rate of HO in this cohort of patients,who underwent Discover disc,was 27.92％ per surgical level and 24.8％ per patient by the last follow-up.There were 19 patients （19.79％） with HO in the single-level group while 12 patients （41.38％） in the double-level group.Conclusions We identified preoperative high-intensity signal in spinal cord,postoperative ROM of surgical level,number of operation level,and PVR as significant risk factors for postoperative HO occurrence.

Lumbar and cervical viscoelastic disc replacement:Concepts and current experience

The ideal lumbar and cervical discs should provide six degrees of freedom andtri-planar (three-dimensional) motion. Although all artificial discs are intended toachieve the same goals, there is considerable heterogeneity in the design oflumbar and cervical implants. The “second generation total disc replacements”are non-articulating viscoelastic implants aiming at the reconstruction ofphysiologic levels of shock absorption and flexural stiffness. This review aims togive an overview of the available implants detailing the concepts and thefunctional results experimentally and clinically. These monobloc prostheses raisenew challenges concerning the choice of materials for the constitution of theviscoelastic cushion, the connection between the components of the internalstructure and the metal endplates and even the bone anchoring mode. Newobjectives concerning the quality of movement and mobility control must bedefined.

Application of a modified surgical position in anterior approach for total cervical artificial disc replacement

BACKGROUND Total cervical artificial disc replacement(TDR)has been considered a safe and effective alternative surgical treatment for cervical spondylosis and degenerative disc disease that have failed to improve with conservative methods.Positioning the surgical patient is a critical part of the procedure.Appropriate patient positioning is crucial not only for the safety of the patient but also for optimizing surgical exposure,ensuring adequate and safe anesthesia,and allowing the surgeon to operate comfortably during lengthy procedures.The surgical posture is the traditional position used in anterior cervical approach;in general,patients are in a supine position with a pad under their shoulders and a ring-shaped pillow under their head.AIM To investigate the clinical outcomes of the use of a modified surgical position versus the traditional surgical position in anterior approach for TDR.METHODS In the modified position group,the patients had a soft pillow under their neck,and their jaw and both shoulders were fixed with wide tape.The analyzed data included intraoperative blood loss,position setting time,total operation time,and perioperative blood pressure and heart rate.RESULTS Blood pressure and heart rate were not significantly different before and after body positioning in both groups(P>0.05).Compared with the traditional position group,the modified position group showed a statistically significantly longer position setting time(P<0.05).However,the total operation time and intraoperative blood loss were significantly reduced in the modified position group compared with the traditional position group(P<0.05).CONCLUSION The clinical outcomes indicated that total operation time and intraoperative blood loss were relatively lower in the modified position group than in the traditional position group,thus reducing the risks of surgery while increasing the position setting time.The modified surgical position is a safe and effective method to be used in anterior approach for TDR surgery.