Complications in posterior cervical spine surgery

The posterior approach to the cervical spine has been described since the early 1900s and it is still commonly used to treat various cervical pathologies. It allows for an extensile exposure of the posterior cervical spine, and when employed for the correct indications it yields good results. However, there are various complications associated with this approach that can negatively impact patient outcomes. In general, avoiding complications is best achieved with careful diagnostic assessment, good patient selection and meticulous technical execution of the surgical procedure. This article reviews some of the most common complications following posterior cervical spine procedures.     

Indications for Anterior Lumbar Interbody Fusion

Anterior lumbar interbody fusion (ALIF) has become a widely recognized surgical technique for degenerative pathology of the lumbar spine. Spinal fusion has evolved dramatically ever since the first successful internal fixation by Hadra in 1891 who used a posterior approach to wire adjacent cervical vertebrae in the treatment of fracture‐dislocation. Advancements were made to reduce morbidity including bone grafting substitutes, metallic hardware instrumentation and improved surgical technique. The controversy regarding which surgical approach is best for treating various pathologies of the lumbar spine still exists. Despite being an established treatment modality, current indications of ALIF are yet to be clearly defined in the literature. This article discusses the current literature on indications on ALIF surgery.     

Bone morphogenetic protein in complex cervical spine surgery: A safe biologic adjunct?

The advent of recombinant DNA technology has substantially increased the intra-operative utilization of biologic augmentation in spine surgery over the past several years after the Food and Drug Administration approval of the bone morphogenetic protein (BMP) class of molecules for indications in the lumbar spine. Much less is known about the potential benefits and risks of the “off-label” use of BMP in the cervical spine. The history and relevant literature pertaining to the use of the “off-label” implantation of the BMP class of molecules in the anterior or posterior cervical spine are reviewed and discussed. Early prospective studies of BMP-2 implantation in anterior cervical spine constructs showed encouraging results. Later retrospective studies reported potentially “life threatening complications” resulting in a 2007 public health advisory by the FDA. Limited data regarding BMP-7 in anterior cervical surgery was available with one group reporting a 2.4% early (< 30 d) complication rate (brachialgia and dysphagia). BMP use in the decompressed posterior cervical spine may result in neurologic or wound compromise according to several retrospective reports, however, controlled use has been reported to increase fusion rates in select complex and pediatric patients. There were no cases of de novo neoplasia related to BMP implantation in the cervical spine. BMP-2 use in anterior cervical spine surgery has been associated with a high early complication rate. Definitive recommendations for BMP-7 use in anterior cervical spine surgery cannot be made with current clinical data. According to limited reports, select complex patients who are considered “high risk” for pseudoarthrosis undergoing posterior cervical or occipitocervical arthrodesis or children with congenital or traumatic conditions may be candidates for “off-label” use of BMP in the context of appropriate informed decision making. At the present time, there are no high-level clinical studies on the outcomes and complication rates of BMP implantation in the cervical spine.     

后前路联合手术治疗严重颈椎退行性疾病

目的探讨后前路联合手术治疗严重颈椎退行性疾病的疗效和手术适应证。方法施行后前路联合手术治疗严重颈椎退行性疾病17例,其中男11例,女6例;年龄46-72岁,平均56.3岁。3例分期后前路手术,14例一期后前路手术。手术步骤为先行后路单开门椎管扩大成形术,然后一期或分期（6个月后）行前路椎管前方减压、植骨融合内固定术。结果无围手术期死亡及神经功能加重病例,术后发生脑脊液漏2例,轴性疼痛2例。术后随访13例,JOA评分由术前平均（8.3±2.28）分增至术后平均（13.1±1.27）分,手术前后评分差异显著（t=11.5,P〈0.01）,脊髓功能改善率为66.5%。结论一期后前路联合手术疗效满意。该手术方式减压充分,可降低单纯前路手术脊髓损伤的风险和减少单纯后路手术后C5神经根麻痹的发生率,适用于全身情况较好、多节段颈椎病变伴脊髓前方局部受压严重的患者。     

Spinal Instrumentation With A Low Complication Rate

Background

Spinal instrumentation has become an increasing part of the armamentarium of neurosurgery and neurosurgical training. For noncontroversial indications for spine fusion the arthrodesis rate seems to be better. For both noncontroversial and controversial indications, the reported complication rate with spinal instrumentation tends to be greater than that with noninstrumented spine surgeries. These reported complications include a 2–3% neurologic injury rate, 3–45% reoperation rate for implant failure, and infection rates of 5–10%. Therefore, we report on 299 cases that have undergone spinal instrumentation placed exclusively by neurosurgeons with a very low complication rate.

Methods

Two hundred ninety-nine consecutive spinal instrumentation cases performed exclusively by neurosurgeons at Indiana University Medical Center were analyzed for complications related to spinal instrumentation. The spinal instrumentation placed consisted of 195 anterior cervical locking plates, 22 cases of posterior cervical instrumentation, 9 cases of combined anterior locking plates with posterior cervical instrumentation, 14 anterior thoraco-lumbar plates, 51 posterior thoraco-lumbar instrumentation cases, and 8 combined anterior/posterior thoraco-lumbar instrumentation cases.

Results

The mean follow-up is 40 months (6–95). There was one perioperative death unrelated to the spinal instrumentation. There were no neurologic injuries and there has been no hardware infection to date. There were two dural tears, three superficial wound infections, and three minor wound breakdowns successfully treated. Hardware complications included three cervical plate/screw extrusions reoperated, one cervical plate fracture reoperated, one posterior cervical screw backout not reoperated, one case of broken pedicle screws not reoperated, one vertebral body failure not reoperated, and one posterior rod case reoperated for excessive rod length and protrusion. The overall complication rate attributable to placement of spinal instrumentation was 10/299 (3%) with a reoperation rate of 2%. The arthrodesis rate was 298/299 (99%).

Conclusion

The complication rate for using spinal instrumentation can be less than previously reported. Lessons learned and discussed should reduce the rate even more. Spinal instrumentation is a safe and useful adjunct to fusion in treating degenerative, traumatic, infectious, and neoplastic diseases of the spine.     

Vascular injury and complication in neurosurgical spine surgery

Summary Vascular injury is an uncommon, but not rare complication of spine surgery. The consequence of vascular injury may be quite devastating, but its incidence can be reduced by understanding the mechanisms of injury. Properly managing vascular injury can reduce mortality and morbidity of patients. A review of the literature was conducted to provide an update on the etiology and management of vascular injury and complication in neurosurgical spine surgery. The vascular injuries were categorized according to each surgical procedure responsible for the injury, i.e., anterior screw fixation of the odontoid fracture, anterior cervical spine surgery, posterior C1–2 arthrodesis, posterior cervical spine surgery, anterolateral approach for thoracolumbar spine fracture, posterior thoracic spine surgery, scoliosis surgery, anterior lumbar interbody fusion (ALIF), lumbar disc arthroplasty, lumbar discectomy, and posterior lumbar spine surgery. The incidence, mechanisms of injury, and reparative measures were discussed for each surgical procedure. Detailed coverage was especially given to vascular injury associated with ALIF, which may have been underestimated. The accumulation of anatomical knowledge and advanced imaging studies has made complex spine surgery safer and more reliable. It is not clear, however, whether the incidence of vascular injury has been reduced significantly in all procedures of spine surgery. Emerging new techniques, such as microendoscopic discectomy and lumbar disc arthroplasty, seem to be promising, but we need to keep in mind their safety issues, including vascular injury and complication.     

Surgical stabilization of the cervical spine. A comparative analysis of anterior and posterior spine fusions

Two hundred twenty-two cervical spine stabilization procedures in 212 patients are reviewed. In 114 posterior cervical fusions, 88 anterior fusions, and ten combined procedures, no deaths occurred. Surgical complication rates were similar, but more severe complications were noted with anterior cervical fusions, including tracheoesophageal problems and transient neurologic loss. Six cases of graft dislodgement requiring reoperation also occurred. In long-term follow-up evaluations, 36 anterior fusion patients developed progressive kyphotic deformity averaging 22 degrees between surgery and the time solid fusion was obtained. Degenerative changes above and below the fusion mass were detected in 36 of 59 patients treated by anterior surgery. Posterior cervical fusion patients were noted to have no significant late change in alignment, and degenerative changes were infrequent. However, 73 of 98 patients had significant extension of fusion mass beyond the originally intended levels of stabilization. Because anterior cervical spine fusion was associated with significant complications of graft dislodgement and tracheoesophageal trauma, as well as postsurgical progressive deformity, the authors recommend posterior wiring and fusion as the procedure of choice to treat cervical spine instability and permit halo-free postsurgical rehabilitation. When anterior neural decompression and fusion is necessary, concomitant posterior wiring and fusion or halo vest immobilization may be necessary to maintain reduction and prevent kyphotic angulation, because posterior ligamentous disruption is not always grossly evident on radiographic examination.     

Cervical anterior transpedicular screw fixation. Part I: Study on morphological feasibility,indications, and technical prerequisites

Multilevel cervical spine procedures can challenge the stability of current anterior cervical screw-and-plate systems, particularly in cases of severe three-column subaxial cervical spine injuries and multilevel plated reconstructions in osteoporotic bone. Supplemental posterior instrumentation is therefore recommended to increase primary construct rigidity and diminish early failure rates. The increasing number of successfully performed posterior cervical pedicle screw fixations have enabled more stable fixations, however most cervical pathologies are located anteriorly and preferably addressed by an anterior approach. To combine the advantages of the anterior approach with the superior biomechanical characteristics of cervical pedicle screw fixation, the authors developed a new concept of a cervical anterior transpedicular screw-and-plate system. An in vivo anatomical study was performed to explore the feasibility of anterior transpedicular screw fixation (ATPS) in the cervical spine. The morphological study was conducted based on 29 cervical spine CT scans from healthy patients and measurements were performed on the pedicle sizes, angulations, vertebral body depth, height and width at C2 to T1. Significant morphologic parameters for the new technique are discussed. These parameters include the sagittal and transverse intersection points of the pedicle axis with the anterior vertebral body wall, as well as the distances between sagittal intersection points from C2 to T1. On the basis of these results, standard spine models were reconstructed and used for the conceptual development of a preclinical release prototype of an anterior transpedicular screw-and-plate system. The morphological feasibility of the new technique is demonstrated, and its indications, biomechanical considerations, as well as surgical prerequisites are thoroughly discussed. In the future, the technique of cervical anterior transpedicular screw fixation might diminish the number of failures in the reconstruction of multilevel and three-column cervical spine instabilities, and avoid the need for supplemental posterior instrumentation.     

Complications in cervical spine surgeries

Complications in cervical spine surgeries can occur infrequently; however, these adverse events can be catastrophic. Each approach to the cervical spine has its own unique set of complications that can occur. Pre-operative planning, vigilance intraoperatively, and careful postoperative care can help avoid complications and allow early detection of adverse events that can prevent long-term sequelae. Both anterior and posterior surgical approaches consistently offer great results, each approach can be technically demanding, and surgeons should be familiar with the appropriate techniques and possible complications.     

Anterior Cervical Spine Surgery for Degenerative Disease: A Review

Anterior cervical spine surgery is an established surgical intervention for cervical degenerative disease and high success rate with excellent long-term outcomes have been reported. However, indications of surgical procedures for certain conditions are still controversial and severe complications to cause neurological dysfunction or deaths may occur. This review is focused mainly on five widely performed procedures by anterior approach for cervical degenerative disease; anterior cervical discectomy, anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion, anterior cervical foraminotomy, and arthroplasty. Indications, procedures, outcomes, and complications of these surgeries are discussed.     

脊柱脊髓损伤的修复与重建进展

目的阐明脊柱脊髓损伤临床与基础的最新进展。方法通过广泛查阅文献，并结合自身的研究结果和临床经验，对近年来脊柱脊髓损伤的临床治疗和基础研究进行总结。结果上颈椎骨折脱位的治疗，以侧块螺钉和椎弓根钉为基础的枕颈融合和寰枢椎融合技术不仅固定牢靠，而且符合生物力学要求。下颈椎骨折脱位的治疗，包括颈前路钢板固定和颈后路侧块或椎弓根钉固定融合术，椎间盘性疾病可考虑人工颈椎间盘置换，则更加符合人体动态的生物力学要求。胸椎骨折手术治疗术式的选择目前仍有争议。近年来，腰椎的动力学固定和人工腰椎间盘置换己取得长足进步，降低了因腰椎融合术而导致的邻近节段病发病率，但缺少长期随访的临床资料。脊髓损伤机制方面的研究，特别是凋亡信号传导机制的研究，近年来取得了很大进展。脊髓损伤的治疗，特别是生物学的治疗，包括细胞移植和基因治疗，均为临床治疗提供了坚实的理论基础。结论随着医学发展和技术创新，脊柱脊髓损伤的修复与重建进展迅速。     

Impact of preoperative neurological status on perioperative morbidity associated with anterior and posterior cervical fusion

OBJECT: Cervical spine fusion is performed for various indications in patient populations ranging from young and healthy to aged and frail. Whereas disease pathoanatomy dictates the surgical approach, preoperative neurological status does not necessarily implicate a specific technique. Although one expects anterior decompression to be performed over fewer segments in healthier patients who experience fewer complications and faster recovery, the impact of pre-operative myelopathy on perioperative complications remains unclear. No large-scale study has evaluated rates of common complications for cervical fusion or their association with surgical approach and neurological status. METHODS: Data for 96,773 patients who underwent cervical fusion for degenerative disease between 1988 and 2003 were collected from the Nationwide Inpatient Sample database. Patients were grouped according to surgical approach (anterior versus posterior) and preoperative neurological status (myelopathic versus nonmyelopathic). Multivariate regression was used to evaluate group effects on selected postoperative complications, length of stay, and disposition at the time of hospital discharge. Although this technique can control for the observed covariates, the absence of key information such as the number of fused levels precludes statistical comparison between patients who underwent anterior or posterior approaches. RESULTS: In this study the authors confirmed that preoperative neurological status impacts perioperative morbidity. For example, patients who were nonmyelopathic and underwent an anterior approach were 7 years younger than the rest of the cohort, and they had a mortality rate of 0.05%. Transfusion was required in 0.34%, and venous thromboembolism occurred in 0.04%. Conversely, these rates were > 13-fold higher in patients with myelopathy who underwent a posterior approach. Furthermore, independent of approach, preoperative myelopathy is highly prognostic of death, pneumonia, transfusion, infection, length of stay, and posthospital disposition. These outcomes at least doubled, with some increasing > 10-fold. CONCLUSIONS: This nationwide study clarifies the frequency and associations of inpatient complications encountered when treating cervical spine disease. Whereas immediate complications due to anterior approaches are limited, patients with myelopathy who undergo a posterior approach have a more sobering outlook. This study shows that clinical myelopathy augments rates of complication during cervical fusion, regardless of the approach. The exclusion of pathoanatomical data from the Nationwide Inpatient Sample database, of key importance in guiding the surgical approach, prevents any conclusions being drawn about the merits and disadvantages of anterior versus posterior surgery.     

Long structural allografts in the treatment of anterior spinal column defects.

A retrospective study of 41 patients who had anterior spinal column reconstruction using long-segment allografts between 1983 and 1998 is reported. A long-segment allograft was defined as an allograft strut that replaces a vertebral body or approximates the height of the adjacent vertebral body for the thoracolumbar or lumbar spine, or more than two vertebral bodies for the cervical or cervicothoracic spine. Forty of the 41 patients had successful anterior strut grafting with radiographic evidence of allograft incorporation at the last followup with the majority of patients having radiographic evidence of incorporation by 6 months. There where three early complications related to the allograft (two end plate fractures and one repeated cervical spine allograft dislodgment) and one late complication associated with the posterior adjunct instrumentation unrelated to the allograft (degenerative lumbar stenosis). The only procedural complication was a deep venous thrombosis and a resultant nonfatal pulmonary embolus. No allografts fractured or collapsed. These data suggest that long-segment anterior allografts work exceptionally well in maintaining vertebral height and structural integrity in numerous pathologic deformities including traumatic and infectious etiologies.     

Rates and risk factors associated with 90-day readmission following cervical spine fusion surgery: analysis of the Michigan Spine Surgery Improvement Collaborative (MSSIC) registry

BACKGROUND CONTEXTHospital readmission rates are an increasingly important focus. Identifying patients at risk for readmission can help decrease those rates and thus decrease the overall cost of care.PURPOSEWe sought to report the rates and the risk factors associated with 90-day hospital readmission after degenerative cervical spine surgery via either an anterior or posterior approach.STUDY DESIGNRetrospective review of prospectively collected databasePATIENT SAMPLEMichigan Spine Surgery Improvement Collaborative (MSSIC) registryOUTCOME MEASURESHospital readmission at 90 daysMETHODSThe MSSIC registry prospectively enrolls patients undergoing surgery for degenerative cervical spine disease. The registry was queried over a 4-year period to determine patient characteristics and risk factors associated with unplanned readmission at 90 days following degenerative cervical spine fusion surgery through either an anterior or posterior approach. Univariate and multivariate regression modeling was used to compare patient characteristics and odds of readmission.RESULTSOf 3,762 patients who underwent an anterior approach, 202 (5.4%) were readmitted within 90 days. Of 693 patients who underwent a posterior approach, 85 (12.3%) were readmitted within 90 days. Risk factors associated with increased likelihood of readmission after the anterior approach were male sex (odds ratio [OR] 1.56, confidence interval [CI] 1.10–2.20), American Society of Anesthesiologists class >2 (OR 1.70, CI 1.26–2.30), and increased length of stay (OR 1.10, CI 1.03–1.19). Factors associated with decreased likelihood of readmission after the anterior approach were being independently ambulatory preoperatively (OR 0.59, CI 0.46–0.76) and holding private insurance (OR 0.67, CI 0.50–0.90). A history of previous spine surgery was associated with increased risk of readmission after the posterior approach (OR 1.76, CI 1.37–2.25). Pain was the most common single reason cited for readmission after either approach (9% anterior, 13% posterior). After an anterior approach, common surgical reasons for readmission include new radicular findings (8%), dysphagia (6%), and surgical site hematoma (5%), whereas common medical reasons include pneumonia (7%), infection outside the surgical site (6%), and an electrolyte issue. After a posterior approach, common surgical reasons for readmission after 90 days include surgical site infection (8%) and new radicular findings (6%), whereas common medical reasons include infection outside the surgical site (9%), urinary tract infection (8%), and an abdominal issue (8%).CONCLUSIONSAnalysis of a large multicentered, spine-specific database for elective cervical spine fusion surgery demonstrated an unplanned 90-day readmission rate of 5.4% for the anterior approach and 12.3% for the posterior approach. Factors associated with readmission for the anterior approach include male sex, American Society of Anesthesiologists class >2, increased length of stay, holding private insurance, and being ambulatory preoperatively. A history of previous spine surgery was associated with increased odds of readmission after the posterior approach.     

Extrapharyngeal (anterolateral) approach to the cervical spine

The extrapharyngeal approach to the anterior cervical spine is a safe, rapid surgical exposure. Other surgical exposures such as the posterior, lateral, and intraoral (transpharyngeal) have inherent limitations that this approach avoids. By going anterior to the sternocleidomastoid muscle and great vessels, the surgical exposure of the anterior cervical spine is wide and the vital structures of the neck are visualized and not injured. We have used this extrapharyngeal approach to treat various disease states of the anterior cervical spine, such as trauma, osteomyelitis, neoplasia, and degenerative disease. Major complications have been neural injury, and pharyngeal fistula.     

Fully endoscopic cervical spine surgery: What does the future hold?

Fully endoscopic cervical spine surgery is an emerging novel approach to address cervical spinal pathology. Techniques, both anterior and posterior have been adapted to address various cervical pathologies. The primary goal of these procedures like other open techniques is to surgically decompress the canal centrally and/or along the foramen. The narrative review aims to provide the reader an overview of the rapidly advancing field of endoscopic cervical spinal surgery and evaluate whether these newer approaches could potentially reduce the cost and the risk associated with instrumented cervical fusion.     

Fracture of anterior cervical plate implant--report of two cases

Anterior cervical plate is a convenient and popular implant employed after corpectomy and bone grafting for traumatic or degenerative cervical spine disease. Although short-segment anterior cervical surgery may adequately be managed with anterior plate fixation alone, multilevel anterior cervical constructs exhibit a relatively high complication rate warranting a simultaneous posterior fusion. We report two patients undergoing two-level anterior corpectomy/fusion with a fixed anterior plate alone and exhibiting plate fracture in conjunction with pseudoarthrosis. The instrument failure was mainly attributed to pseudoarthrosis. However, improper contouring of the plate causing microstructural damage might create a weak point and contributed to this unusual hardware failure.     

Fracture of anterior cervical plate implant – report of two cases

Summary Anterior cervical plate is a convenient and popular implant employed after corpectomy and bone grafting for traumatic or degenerative cervical spine disease. Although short-segment anterior cervical surgery may adequately be managed with anterior plate fixation alone, multilevel anterior cervical constructs exhibit a relatively high complication rate warranting a simultaneous posterior fusion. We report two patients undergoing two-level anterior corpectomy/fusion with a fixed anterior plate alone and exhibiting plate fracture in conjunction with pseudoarthrosis. The instrument failure was mainly attributed to pseudoarthrosis. However, improper contouring of the plate causing microstructural damage might create a weak point and contributed to this unusual hardware failure.     

下颈椎内固定治疗进展及问题探讨

本文介绍了下颈椎前路和后路使用各种器械进行内固定的最新方法,并对其中常见的一些问题进行了探讨。颈椎前路钢板螺钉内固定系统可以明显提高植骨融合率,其并发症以内固定松动或失败最为常见,简要介绍了预防该并发症在操作时需注意的各种事项及方法。颈椎前路界面固定技术可以无须另外取自体髂骨或腓骨等进行植骨,避免了二次手术的并发症。人工椎间盘置换术可以避免融合后相邻节段的继发退变以及由此引起的新症状,最终疗效还需要大宗病例积累和长期随访结果证实。颈椎侧块螺钉内固定操作方法较多,但比较简单,固定可靠。对神经根、脊髓的损伤是其最重要的并发症,熟悉颈椎解剖可以避免这些并发症。颈椎椎弓根内固定技术是目前固定最为牢固的方法,操作比较困难,主要并发症是螺钉穿破椎弓根,术前仔细的影像学研究或使用导航技术,做到个体化置钉,可以有效提高置钉准确率。     

Anterior cervical discectomy and fusion: Techniques,complications, and future directives

Anterior cervical discectomy and fusion is a well-established surgical intervention for a wide range of degenerative cervical spine pathology, including myelopathy and radiculopathy. Despite the emergence of technical advances including cervical disk arthroplasty, evidence continues to support use of anterior cervical fusion given its effectiveness and safety. Research continues to advance anterior cervical fusion with the development of patient-specific implants and hybrid arthroplasty-fusion surgical approaches. This review summarizes the indications, surgical approach, outcomes, and complications of anterior cervical fusion and offers perspective on future areas of research within the context of newer motion-preserving alternatives, including cervical disk arthroplasty.