Increased fusion rates with cervical plating for three-level anterior cervical discectomy and fusion

STUDY DESIGN: A retrospective review of all patients surgically treated by a single surgeon with a three-level anterior cervical discectomy and fusion with and without anterior plate fixation. OBJECTIVES: To compare the clinical and radiographic success of anterior three-level discectomy and fusion performed with and without anterior cervical plate fixation. SUMMARY OF BACKGROUND DATA: Previous studies of multilevel cervical discectomies and fusions have shown fusion rates to decrease as the number of surgical levels increases. Anterior cervical plate stabilization can provide more stability and may increase fusion rates for multilevel fusions. METHODS: Over a 7-year period, 59 patients were treated surgically with a three-level anterior cervical discectomy and fusion by the senior author. Forty patients had cervical plates, whereas 19 had fusions with no plates. These patients were observed for an average of 3.2 years. Clinical and radiographic follow-up data were obtained. RESULTS: Of the 59 patients, 14 had a pseudarthrosis (7 in each group). The pseudarthrosis rates were 18% (7 of 40) for patients with plating and 37% (7 of 19) for patients with no plating. Although the nonunion rate for unplated fusions was double that of plated fusions, this difference was not statistically significant. There was no statistically significant correlation between pseudarthrosis and gender, age, level of surgery, history of tobacco use, or previous anterior surgery. The fusion rates were improved with the use of a cervical plate. Inferior clinical results were demonstrated in patients with a pseudarthrosis, regardless of the use of a cervical plate. CONCLUSIONS: The addition of plate fixation for three-level anterior cervical discectomy and fusion is a safe procedure and does not result in higher complication rates. In this study, the pseudarthrosis rate was lower for patients with a cervical plate. However, this difference was not statistically significant. Patients treated with cervical plating had overall better results when compared with those of patients treated without cervical plates. Although the use of cervical plates decreased the pseudarthrosis rate, a three-level procedure is still associated with a high nonunion rate, and other strategies to increase fusion rates should be explored.     

Nonunion following two-level anterior cervical discectomy and fusion

Nonunion is a potential complication of anterior cervical discectomy and fusion (ACDF). There are reports that cite the prevalence of nonunion for two-level ACDF with various fusion techniques, but they do not recommend treatment alternatives. Pseudarthrosis after a two-level ACDF occurred in a 69-year-old man. Posterior cervical wiring and autograft resulted in a successful fusion anteriorly and posteriorly. Posterior fusion augments stability, enhances the potential for eventual anterior fusion, avoids the risks of an additional anterior procedure, and is an excellent therapeutic alternative to a second anterior attempt at stabilization.     

Initial intervertebral stability after anterior cervical discectomy and fusion with plating

BACKGROUND CONTEXT: Anterior cervical locking plates are currently used to provide secure fixation, which appears to help promote fusion, although the details of the in vivo biomechanical effects of plating on the spine are unknown. PURPOSE: To determine if any motion was present initially in the plated anterior cervical discectomy and fusion (ACDF) and, if so, where the motion occurred. STUDY DESIGN: A cohort of patients that were part of a prospective study on postoperative changes after cervical fusion were evaluated for motion at the fusion site about 2 weeks after ACDF. METHODS: Forty-eight segments in 27 patients undergoing ACDF with a cervical plate were evaluated. The patients underwent flexion and extension radiography approximately 2 weeks after surgery. Intervertebral motion at the fusion site was evaluated with validated quantitative motion analysis. RESULTS: Motion was perceived at 29 levels in 18 patients. The sources of motion were either actual bending of the plate itself, motion at the screw-bone interface, or screw-plate interface. CONCLUSIONS: In many patients, anterior cervical plating after ACDF does not eliminate motion at the fusion site. Depending on the quality of bone, type of bone graft, and nature of the injury, this information may influence decisions regarding implants and postoperative bracing.     

The effect of cervical plating on single-level anterior cervical discectomy and fusion

The use of anterior plates for single-level cervical fusions is controversial. Previous studies that evaluated single and multiple-level fusions have shown increased and decreased fusion rates when cervical plates are used. The purpose of this study was to compare the clinical and radiographic success of single-level discectomy performed with and without anterior cervical plate fixation. During a 6-year period, 80 patients were surgically treated with a single-level anterior cervical discectomy. Forty-four patients had cervical plates, whereas 36 had fusions without plates (average follow-up, 2.3 years). The pseudarthrosis rates were 4.5% (2 of 44) for patients with plating and 8.3% (3 of 36) without plating. This difference was not significant (p = 0.653). There was no correlation of pseudarthrosis with sex, age, level of surgery, history of tobacco use, or the presence of previous anterior surgery. The amount of graft collapse for patients with plating was 0.75 mm compared with 1.5 mm for those without a plate (p = 0.026). The amount of kyphotic deformity of the fused segment was 1.2 degrees with plating compared with 1.9 degrees for patients without plating (p = 0.079). Ninety-one percent of the patients with plating had good or excellent results compared with 88% in the group without cervical plates, based on Odom's criteria. The addition of plate fixation for single-level anterior cervical discectomy and fusion is safe and not associated with a significant increase in complication rates. The pseudarthrosis rates are not significantly different when a cervical plate is used.     

Static versus dynamic plating for multilevel anterior cervical discectomy and fusion.

BACKGROUND CONTEXT: Dynamic anterior plates have been popularized to promote cervical spine fusion by allowing controlled settling, thereby promoting load sharing across the construct. To date these proposed benefits have been largely theoretical and there are no studies confirming any benefits over more traditional static plates. PURPOSE: To compare the clinical and radiographic outcomes of patients undergoing an instrumented multilevel anterior cervical discectomy and fusion (ACDF) with either a static or dynamic plate design. STUDY DESIGN: A retrospective clinical and radiographic study. PATIENT SAMPLE: From 1997 to 2002, 52 patients with either radiculopathy or myelopathy underwent two- or three-level ACDF with either static or dynamic plate fixation. OUTCOME MEASURES: Functional outcome, fusion status, radiographic measurements. METHODS: A statically locked plating system was used in 21 patients, and a dynamic plating system was used in 31 patients. Functional outcome, fusion status, plate migration, settling, and adjacent-level disc space impingement were evaluated. RESULTS: Clinical outcome was found to be similar between the statically and dynamically plated groups. Eighty-four percent of patients in both groups experienced good or excellent results at final follow-up. We observed a higher rate of nonunion in patients treated with a dynamic plate (16% [5 of 31]) compared with a rate of 5% (1 of 21) in those patients treated with a static plate (p=.05). Settling of the construct and plate migration was similar between the study groups at all time points. CONCLUSIONS: This study failed to confirm our hypothesis that a dynamic plate (that allows angular motion between the screws and plate) confers any clinical or radiographic advantage over earlier design static plates. A higher rate of nonunion was actually seen in the dynamically plated patients; however, clinical results were similar between the two groups.     

A comparison of fusion rates between single-level cervical corpectomy and two-level discectomy and fusion

A single corpectomy and strut grafting has been proposed as an alternative to performing two-level adjacent discectomies with multiple grafts to produce superior fusion rates. The purpose of this study was to compare the clinical and radiographic success of two-level discectomy and fusion with anterior cervical plate fixation compared with a single-level corpectomy. Fifty-two patients were treated with either a two-level adjacent anterior cervical discectomy and fusion with cervical plating, or by a single-level corpectomy and plate. Thirty-two patients had two-level discectomies, whereas 20 had a single corpectomy and a strut graft (average follow-up was 3.6 years). One patient had a pseudarthrosis from a single-level corpectomy and required subsequent surgery to obtain an osseous union. The fusion rates between the two groups was not statistically significant (p = 0.385). The clinical results of the surgeries were similar between the groups based on Odom's criteria. The addition of cervical plates to either two-level discectomies or single-level corpectomies yielded similar fusion and complication rates.     

颈椎前路椎间盘切除、植骨融合内固定术治疗脊髓型颈椎病术后轴性症状的前瞻性研究

【摘要】 目的：前瞻性分析若干临床因素与颈前路椎间盘切除、植骨融合内固定治疗脊髓型颈椎病术后颈部轴性症状发生的相关性。方法：2011年5月～2011年9月间接受由同一专业组术者完成的颈椎前路椎间盘切除、椎体间植骨融合、钛板内固定术患者107例,术前均无颈部疼痛、僵硬等轴性症状,均于术后3个月在门诊复查。采用日本骨科协会改良17分评分法（modified Japanese Orthopaedics Association,mJOA）改善率评价患者术后神经功能恢复情况,观察术后新出现的颈部轴性症状的发生率并使用视觉模拟评分法（visual analogue scale, VAS）评价轴性症状的程度。收集所有患者的年龄、性别、术前/术后手术节段曲度、手术节段椎间撑开高度、植骨融合情况、术后项背肌功能锻练及术后围领佩戴时间等八项临床相关因素,使用Logistic回归分析上述临床因素对术后出现颈部轴性症状的影响。使用独立样本t检验分析轴性症状与术后神经功能改善的关系。结果：本组107例患者中男性56例,女性51例,年龄29~80岁,平均52.2岁。手术节段：单节段49例（45.8%）,双节段47例（43.9%）,三节段11例（10.3%）。本组患者术后3个月复查时新出现的颈部轴性症状发生率为26.2%（28/107）,VAS平均为4分（2~8分）。所研究的八项临床相关因素中,术后项背肌功能锻练（P=0.0003,OR=185.6）、手术节段术前曲度（P=0.003,OR=8.1）和植骨融合情况（P=0.016,OR=37.1）与术后发生颈部轴性症状有相关性。术后出现新发轴性症状患者术后mJOA评分改善率为58.6%±32.8%,未发生轴性症状患者术后mJOA改善率为65.5%±30.6%,两组结果无统计学差异（P=0.317）。结论：颈椎前路术后新发颈部轴性症状并不少见。术后项背肌功能锻炼差、术前手术节段后凸和无植骨融合迹象与术后新发轴性症状有关。     

Interobservational variation in determining fusion rates in anterior cervical discectomy and fusion procedures

The fusion rate represents one of the most commonly used criteria for evaluating the efficacy of spinal surgical techniques and the effectiveness of newly developed instrumentation and spinal implants. Reported fusion rates are not frequently supported by adequate information regarding by whom and how fusion was defined. In our prospective study we examined the fusion rate in patients undergoing first time anterior cervical discectomy and fusion for degenerative disease. Separate, well-defined radiographic fusion criteria were used and the 12-month post-operative X-rays were reviewed independently by a neurosurgeon, a neuroradiologist and an orthopedic surgeon, who were not involved in the patients’ management. The observed fusion rates were 77.3, 87.8 and 84.7% respectively. Statistical analysis demonstrated concordance rates of 87.8, 91 and 91.4% and Kappa coefficients of 0.585, 0.620 and 0.723 for each pair of evaluators. Another set of ratings of the same radiographs, by the same interviewers, was obtained 6 weeks after the initial one. The reported fusion rates were 78.2% for the neurosurgeon, 87.4% for the orthopedic surgeon, and 86.1% for the neuroradiologist. Statistical analysis demonstrated intra-observer concordance rates of 98.7, 92.2 and 97.9% respectively, while the Kappa coefficients were 0.963, 0.677 and 0.907 for each reviewer. Our findings confirm the necessity of defining and describing criteria for fusion whenever this rate is reported in clinical series. The lack of widely accepted, well-defined criteria makes comparison of these results difficult. The development of a well organized, prospective clinical study in which fusion and outcome will be assessed by both clinical and radiographic parameters could significantly contribute to a more accurate evaluation of overall outcome of cervical spinal procedures.     

Solis融合器与自体髂骨块植骨联合钛板治疗单节段脊髓型颈椎病的疗效比较

目的比较Solis融合器与自体髂骨块植骨联合钛板治疗单节段脊髓型颈椎病的疗效,并探讨Solis融合器的适应证选择和应用注意事项。方法回顾性分析自2008-01—2012-06行手术治疗且资料完整的39例单节段脊髓型颈椎病,行颈前路减压植骨融合术(ACDF),其中使用Solis融合器植骨融合者为A组(n=19),使用自体髂骨块植骨联合钛板内固定者为B组(n=20);2组性别比、年龄、病程、术前JOA评分及手术节段分布比较,差异均无统计学意义。比较2组手术时间、术中出血量、平均住院时间、术后JOA评分及JOA改善率、椎间融合率和并发症发生率。结果所有患者获得随访22~45个月,平均32个月。术后症状改善率和融合率2组比较差异均无统计学意义(P0.05)。A组1例发生融合器下沉,B组1例术后取骨区血肿形成、2例术后1年发生取骨处疼痛、2例术后发生吞咽困难,2组并发症发生率差异有统计学意义(P0.05)。结论应用Solis融合器和与自体髂骨块植骨联合钛板治疗单节段脊髓型颈椎病均可取得较好的疗效,Solis融合器操作简便、术后并发症发生率较低,但对于严重骨质疏松的患者,不宜单独使用Solis融合器。     

Outpatient anterior cervical discectomy and fusion

The study reported here examined patient safety and satisfaction in 56 patients with cervical radiculopathy secondary to foraminal stenosis or a herniated disc who underwent a total of 58 outpatient anterior cervical discectomy and fusion (ACDF) procedures with iliac crest bone graft or fibular allograft. Patients were discharged 0.8 hour to 6.5 hours (mean, 2.4 hours) after surgery and received 3 home health care visits over 24 hours. Of the 45 satisfaction questionnaires that were completed, 43 (95.6%) indicated patients were satisfied or very satisfied with the surgery, and 35 (77.8%) indicated patients would have the procedure performed on an outpatient basis again. Eleven (19.6%) of the 56 patients did not respond to a satisfaction questionnaire. Outpatient ACDF has high patient satisfaction but does not compromise patient safety.     

椎体次全切除与椎间隙减压治疗多节段颈椎病的疗效比较

目的 比较椎体次全切除减压植骨融合术(anterior cervical corpectomy with fusion,ACCF)和经椎间隙减压植骨融合术(anterior cervical discectomy with fusion,ACDF)治疗多节段颈椎病的临床疗效及影像学结果.方法 回顾性分析2002年6月～...     

两节段颈前路椎间盘切除的力学研究

目的评价两节段颈前路椎间盘切除、植骨、钢板内固定稳定性情况.方法取5具新鲜成人尸体颈椎标本(C2～T1),先后制成完整颈椎标本、C4～5、C5～6颈椎间盘切除、植骨、植骨加前路钢板内固定模型.非破坏方式下依次检测和评价颈椎在上下、后前、左右水平方向的载荷及移位情况.结果单纯植骨能增加两节段颈椎间盘切除模型上下、左右方向刚度,具有统计学意义(P＜0.05),而对后前剪切刚度意义不大.前路钢板则增加以上3个方向的刚度(P＜0.05).结论植骨可以提高两节段颈椎间盘切除后颈椎的稳定性,但不能提供后前方向稳定.前路钢板则可以明显提高3个方向的颈椎稳定性.     

One- and two-level anterior cervical discectomy and fusion: the effect of plate fixation.

BACKGROUND CONTEXT: The success of arthrodesis for anterior cervical fusion depends on several factors, including the number of surgical levels. Internal fixation putatively improves the arthrodesis rate and outcome. PURPOSE: To provide medium-term follow-up data on the surgical success and patient outcome of one- and two-level anterior cervical discectomies and fusions and to determine the effect that plate fixation has on results. STUDY DESIGN: A prospective study of 40 patients who underwent modified Smith-Robinson anterior cervical discectomy and fusion at one or two operative levels. PATIENT SAMPLE: Forty patients. OUTCOME MEASURES: Odom criteria, Nurick grading system, radiographs. METHODS: Forty patients, with an average age of 44 years (range, 27 to 82), were followed for an average of 51 months (range, 24 to 85). All had an anterior discectomy, burring of the end plates and placement of an autogenous tricortical iliac crest graft at one (20 patients) or two levels (20 patients). Twenty-three were stabilized with the Cervical Spine Locking Plate (Synthes Spine, Paoli, PA), 4 single level, 19 two level. All patients had follow-up office visits with examinations and radiographs. Radiographic union, postoperative pain relief and neurologic recovery were evaluated.RESULTS: Successful arthrodesis of single-level procedures occurred in 11 of 16 unplated and 2 of 4 plated fusions. Primary bony union in the two-level group was achieved in 15 of 19 plated patients and did not occur in the single unplated procedure. Clinically, there were 12 excellent, 5 good, 3 satisfactory and 0 poor outcomes among the single-level procedures. Among the dual-level procedures, there were 10 excellent, 5 good, 3 satisfactory and 2 poor results. Nine of 16 who developed adjacent-level degeneration had pain. Five of the 9 also had nonunions. Of the 40, 3 had fibrous union at final follow-up, and 10 had revision surgery. CONCLUSIONS: The Cervical Spine Locking Plate improved the outcome of two-level procedures to that of uninstrumented one-level fusions. Adjacent-level degeneration is associated with persistent pain, especially if there is also a nonunion. Primary bony union is paralleled by a better clinical outcome.     

Microsurgical anterior cervical discectomy without fusion

Objectives  

Microsurgical anterior exposure and removal of cervical herniated disk without fusion of the involved motion segment to relieve radicular pain and to restore function.     

双节段前路颈椎自锁式融合器融合术后矢状位影像学参数的变化

目的 :观察应用自锁式融合器行前路颈椎融合术(anterior cervical discectomy and fusion,ACDF)后矢状位影像学参数的变化。方法:回顾性分析2010年1月~2014年6月160例接受ACDF的双节段颈椎病患者,其中应用MC+融合器(单锚定组)78例,ROI-C融合器(双锚定组)82例。测量术前、术后3d、术后3个月及末次随访时颈椎侧位X线片的影像学参数,包括手术节段椎间隙高度(height of operation segment,HOS)、椎间隙角度(angle of operation segment,AOS)、C2-C7角、C2-C7矢状位轴向距离(C2-C7 sagittal vertical axis,C2-C7 SVA)及T1倾斜角(T1 slope,T1S),并应用Erk五度分级法评价术后3个月及末次随访时的植骨融合情况。采用Pearson相关性分析160例患者各时间点影像学参数间的相关性;运用独立样本t检验对比同时间点两组间各影像学参数的差异;使用配对样本t检验分别对两组组内不同时间点时各参数进行对比;两组间术后3个月及末次随访时的融合等级对比采用Mann-Whitney U检验;术后3个月及末次随访时两组组内融合等级对比运用Wilcoxon符号秩检验。结果:术后随访13.42±6.01个月(6~31个月)。术前、术后3d、术后3个月及末次随访时AOS与C2-C7角、C2-C7角与T1S、AOS与T1S、T1S与C2-C7 SVA均呈正相关(P0.01),C2-C7SVA与AOS、C2-C7角均无显著相关性(P0.01)。术后3d、3个月及末次随访时两组HOS、AOS、C2-C7角及T1S较术前均有增加(P0.05),术后3个月及末次随访时,双锚定组AOS、C2-C7角及T1S均高于单锚定组,两组比较存在统计学差异(P0.05)。两组术后3个月及末次随访时融合等级对比无统计学差异(P0.05),末次随访时两组融合等级较术后3个月时下降(P0.05)。结论:应用两种自锁式融合器行双节段ACDF均可恢复手术节段椎间隙的高度、角度以及颈椎曲度,ROI-C融合器较MC+融合器对维持术后手术节段角度及颈椎前凸更具优势。ACDF术后颈椎曲度的丢失可能引起胸椎矢状位影像学参数的变化。     

Outpatient anterior cervical discectomy and fusion.

The study reported here examined patient safety and satisfaction in 56 patients with cervical radiculopathy secondary to foraminal stenosis or a herniated disc who underwent a total of 58 outpatient anterior cervical discectomy and fusion (ACDF) procedures with iliac crest bone graft or fibular allograft. Patients were discharged 0.8 hour to 6.5 hours (mean, 2.4 hours) after surgery and received 3 home health care visits over 24 hours. Of the 45 satisfaction questionnaires that were completed, 43 (95.6%) indicated patients were satisfied or very satisfied with the surgery, and 35 (77.8%) indicated patients would have the procedure performed on an outpatient basis again. Eleven (19.6%) of the 56 patients did not respond to a satisfaction questionnaire. Outpatient ACDF has high patient satisfaction but does not compromise patient safety.     

前路减压椎间桥形融合器ROI-C置入治疗连续双节段脊髓型颈椎病的疗效对比

目的 :比较颈椎前路减压椎间桥形融合器ROI-C置入与传统钛板联合cage融合固定治疗连续双节段脊髓型颈椎病的临床疗效。方法:回顾性分析2011年1月~2012年12月我科行颈椎前路减压应用ROI-C或传统钛板联合cage融合固定治疗的连续双节段脊髓型颈椎病患者57例,25例患者采用ROI-C作为内置物(A组),32例患者采用cage和前路钛板作为内置物(B组),两组患者年龄、性别比、术前JOA评分、术前颈痛VAS评分及手术节段均无统计学差异。比较两组手术时间、术中出血量、术后JOA评分、术后颈痛VAS评分、颈椎生理曲度(Cobb角)、手术节段前凸角、融合率、吞咽困难发生率及邻近节段退变率。结果:A组手术时间141.3±49.9min,术中出血量123.6±54.1ml,B组分别为168.3±44.4min和126.2±32.6ml,A组手术时间低于B组(P0.05),两组术中出血量相比差异无统计学意义(P0.05)。术后3个月及末次随访时,两组JOA评分均显著高于术前水平,差异有统计学意义(P0.05);两组颈痛VAS评分较术前明显下降,差异有统计学意义(P0.05);两组间同时间点JOA及VAS均无显著性差异(P0.05)。A组术前、末次随访时颈椎生理曲度分别为12.6°±7.3°、21.9°±6.2°;B组分别为14.3°±9.3°、19.6°±7.3°,两组末次随访时颈椎曲度较术前明显改善,差异有统计学意义(P0.05),两组间同时间点差异无显著性(P0.05)。A组术前、末次随访时手术节段前凸角分别为3.4°±5.6°、9.6°±5.5°;B组分别为4.4°±4.3°、9.1°±4.1°,两组手术节段术后前凸角较术前明显增高,差异有统计学意义(P0.05);两组间同时间点比较差异无显著性(P0.05)。A组术后有2例诉轻度吞咽困难,吞咽困难发生率8%(2/25),B组术后有10例诉轻度吞咽困难,1例诉中度吞咽困难,吞咽困难发生率34.4%(11/32),两组吞咽困难发生率相比差异有统计学意义(P0.05)。A组术后3个月手术节段融合率88%(22/25),B组术后3个月手术节段融合率87.5%(28/32),末次随访两组手术节段均获得骨性愈合。A组50个邻近节段中有6个节段椎间盘信号发生退变或退变级别加重,B组64个邻近节段中有8个节段椎间盘信号发生退变或退变级别加重,两组邻近节段退变率无统计学差异(P0.05)。结论:颈椎前路减压后应用ROI-C固定治疗连续双节段脊髓型颈椎病可以获得与传统cage联合前路钛板固定相似的临床疗效,但使用ROI-C置入具有手术时间短、术后吞咽困难率低等优点。     

Assessment of fusion after anterior cervical discectomy

There is no established method to assess fusion in patients following anterior cervical discectomy. In this study we have made a series of measurements to detect movement between vertebrae adjacent to an operated space. The absence of movement implies structural union between adjacent vertebrae. Measurements have been made in two distinct surgical groups. Group A patients had anterior cervical discectomy with insertion of a BOP graft into the disc space. Group B patients underwent simple anterior cervical discectomy with no spacer or graft material inserted, the disc space being left empty. Details of the measurements and interpretation of results are described. In the absence of a 'gold standard' to assess bony union we propose that these measurement methods provide an objective and scientific method to assess fusion at the operated level after anterior cervical discectomy. Objective measurement of fusion will allow comparison between different surgical techniques that claim fusion as an end point. It will also become possible to study the influence of fusion on clinical outcome in different surgical populations.