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

STUDY DESIGN: A retrospective review of all patients surgically treated with a two-level anterior cervical discectomy and fusion with and without anterior plate fixation by a single surgeon. OBJECTIVES: To compare the clinical and radiographic success of two-level discectomy and the effect of anterior cervical plate fixation. SUMMARY OF BACKGROUND DATA: Prior studies of multisegment fusions have shown decreased fusion rates correlating with the number of increased levels. The use of anterior plates for single-level cervical fusions is controversial. However, their use in multilevel fusions may be warranted because of the increased pseudarthrosis rates. METHODS: Over a 6-year period, 60 patients were treated surgically with a two-level anterior cervical discectomy and fusion by the senior author. Thirty-two patients had cervical plates, and 28 underwent fusions without plates. These patients were followed for an average of 2.7 years. Clinical and radiographic follow-up evaluations were performed. RESULTS: Of the 60 patients, 7 had a pseudarthrosis. The pseudarthrosis rates were 0% for patients with plating and 25% for those with no plating. This difference was statistically significant (P = 0.003). No correlation of pseudarthrosis with gender, age, level of surgery, history of tobacco use, or the presence of prior anterior surgery was found. There was significantly less graft collapse (P = 0.0001) in the patients without plates in whom pseudarthrosis developed (1.4 mm) than in those who had fusions with plates (0.3 mm). The amount of kyphotic deformity of the fused segment was 0.4 degree in patients with plating compared with 4.9 degrees in those without plating who developed a pseudarthrosis (P = 0.0001). CONCLUSIONS: The addition of plate fixation for two-level anterior cervical discectomy and fusion is a safe procedure with no significant increase in complication rates. The pseudarthrosis rates are significantly higher in patients treated without plate fixation. No nonunions occurred in the patients treated with plate fixation. There was significantly less disc space collapse and kyphotic deformity with the plated fusions than with the nonplated fusions, in which a pseudarthrosis developed. The complication rates for plated fusions are extremely low and do not differ from those for nonplated fusions.     

Does rigid instrumentation increase the fusion rate in one-level anterior cervical discectomy and fusion?

BACKGROUND CONTEXT: Although plate fixation enhances the fusion rate in multilevel anterior cervical discectomy and fusion (ACDF), debate exists regarding the efficacy of nonplating to rigid plate fixation in one-level ACDF. PURPOSE: To determine the efficacy of nonplating to rigid plate fixation in regards to fusion rate and clinical outcome in patients undergoing one-level ACDF with autograft. STUDY DESIGN: A review of 69 consecutive patients who underwent one-level ACDF with autograft and with or without rigid anterior cervical plate fixation. PATIENT SAMPLE: Sixty-nine patients who underwent one-level ACDF (mean age, 45 years) were evaluated for radiographic evidence of fusion (mean, 14 months) and for clinical outcome. All patients received tricortical iliac crest autografts. Disc space distraction was 2 mm, the grafts were inserted with the cortical surface positioned anteriorly, and each graft was countersunk 2 mm from the anterior vertebral border. Thirty-eight patients underwent nonplated ACDF and 31 patients underwent plated ACDF. Eighteen Orion (Sofamor-Danek, Memphis, TN), eight Atlantis (Sofamor-Danek) and five PEAK polyaxial (Depuy-Acromed, Rayham, MA) anterior cervical plating systems were used. Rigid plate fixation was used in all patients with instrumentation. Postoperatively, hard collars were worn 6 to 8 weeks in nonplated patients and soft collars were worn for 3 to 4 weeks in plated patients. Twenty-four patients were smokers (54.2% nonplating; 45.8% plating) and work-related injuries entailed 23 patients (47.8% nonplating; 52.2% plating). OUTCOME MEASURES: Fusion was assessed based on last follow-up of lateral neutral, flexion and extension radiographs. Radiographs were evaluated blindly to assess fusion and instrumentation integrity between nonplated and plated patients. Clinical outcomes were assessed with the Cervical Spine Outcomes Questionnaire and also assessed on last follow-up as excellent, good, fair or poor based on Odom's criteria. METHODS: Fusion rate and postoperative clinical outcome were assessed in 69 patients who underwent one-level ACDF with autograft and with or without rigid anterior plate fixation. Additional risk factors were also analyzed. Statistical significance was established at p<.05. RESULTS: Sixty-six patients (95.7%) achieved a solid fusion (100% nonplated; 90.3% plated). Nonunions occurred in three patients (1 smoker; 2 nonsmokers) with Orion instrumentation. Slight screw penetration into the involved and uninvolved interbody spaces occurred in one patient who was a nonsmoker and did not achieve fusion. One superficial cervical wound infection was noted in a nonplated patient. No other intraoperative or postoperative complications were noted. No statistically significant difference was noted between nonplating to rigid plating upon fusion rate (p>.05). All nonunions occurred at the C5-C6 level. Mean estimated intraoperative blood loss was significantly greater in plated patients (p=.043). Revision surgery involved 9.7% of the plated patients, whereas none of the nonplated patients required reoperation. Postoperative clinical outcome was assessed in all patients (mean, 21 months). Excellent results were noted in 18.8%, good results in 72.5% and fair results in 8.7% of the patients. Nonunion patients reported satisfactory clinical outcome. No statistical significance was noted between clinical outcome of fused and nonfused patients, the presence of a work-related injury and the use of plating (p>.05). Demographics and history of smoking were not factors influencing fusion or clinical outcome in this series (p>.05). The effect on fusion by various plate types could not be discerned from this study. CONCLUSION: A 100% and 90.3% fusion rate was obtained for one-level nonplated and plated ACDF procedures with autograft, respectively. The effects of smoking or level of fusion could not be discerned from these one-level cases. Excellent and good clinical outcome results were obtained for 91.3%. Nonplating or rigid plate fixation for ACDF in properly selected patients to treat radiculopathy with or without myelopathy has a high fusion rate and yields a satisfactory clinical outcome. Although controversy exists as to the efficacy of rigid plate fixation in one-level ACDF, solid bone fusion can be adequately obtained without plate fixation and instrumentation-related complications can be avoided. In line with the literature, plate fixation should be reserved for patients unwilling or unable to wear a hard orthosis postoperatively for an extended period of time or for those patients who seek a quicker return to normal activities. Proper patient selection, meticulous operative technique and postoperative care is essential to promote optimal graft-host incorporation.     

Anterior cervical fusion with interbody cage containing β-tricalcium phosphate augmented with plate fixation: a prospective randomized study with 2-year follow-up

A variety of bone graft substitutes, interbody cages, and anterior plates have been used in cervical interbody fusion, but no controlled study was conducted on the clinical performance of β-tricalcium phosphate (β-TCP) and the effect of supplemented anterior plate fixation. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting interbody fusion cage containing β-TCP for the treatment of cervical radiculopathy and/or myelopathy, and the fusion rates and outcomes in patients with or without randomly assigned plate fixation. Sixty-two patients with cervical radiculopathy and/or myelopathy due to soft disc herniation or spondylosis were treated with one- or two-level discectomy and fusion with interbody cages containing β-TCP. They were randomly assigned to receive supplemented anterior plate (n = 33) or not (n = 29). The patients were followed up for 2 years postoperatively. The radiological and clinical outcomes were assessed during a 2-year follow-up. The results showed that the fusion rate (75.0%) 3 months after surgery in patients treated without anterior cervical plating was significantly lower than that (97.9%) with plate fixation (P < 0.05), but successful bone fusion was achieved in all patients of both groups at 6-month follow-up assessment. Patients treated without anterior plate fixation had 11 of 52 (19.2%) cage subsidence at last follow-up. No difference (P > 0.05) was found regarding improvement in spinal curvature as well as neck and arm pain, and recovery rate of JOA score at all time intervals between the two groups. Based on the findings of this study, interbody fusion cage containing β-TCP following one- or two-level discectomy proved to be an effective treatment for cervical spondylotic radiculopathy and/or myelopathy. Supplemented anterior plate fixation can promote interbody fusion and prevent cage subsidence but do not improve the 2-year outcome when compared with those treated without anterior plate fixation. This study was supported by Shanghai Natural Science Foundation (No. 044119626).     

神经根型颈椎病的手术治疗

目的 探讨神经根型颈椎病（cervical spondylotic rad icu lopathy,CSR）的手术指征和手术方式。方法 观察CSR 16例,行颈椎前路椎间盘切除及植骨融合10例,行后路手术6例,其中单纯椎间孔减压2例,单开门椎管扩大成形加神经根管减压4例。16例患者中有8例加行颈椎钛板固定。结果 14例获随访,平均3年4个月（6月-10年）。根据M acnab疗效评价标准,优10例,良3例,可1例,优良率92.9%。结论 前路减压术或后路成形扩大术治疗严重的CSR能获得比较满意的疗效。     

Anterior cervical plating enhances arthrodesis after discectomy and fusion with cortical allograft

OBJECTIVE: Anterior plate fixation has gained widespread acceptance for the treatment of cervical spondylosis, theoretically enhancing the rate of arthrodesis. There are few studies comparing fusion rates after anterior cervical discectomy and fusion (ACDF) with and without a plate. The purpose of this study was to evaluate the efficacy of anterior cervical plating for fusion enhancement after one- and two-level ACDF with cortical allograft. METHODS: A retrospective review was performed with 251 patients who underwent one- or two-level ACDF with cortical allograft and plate stabilization between 1993 and 1999. An independent surgeon reviewer determined fusion status and complications. A successful fusion was defined by the absence of lucency around the graft, evidence of bridging bone between the endplate and the graft, and the absence of movement on dynamic imaging scans. Follow-up data, ranging from 9 months to 3.6 years, were available for 233 patients. A control group of 289 patients who underwent ACDF without plating was described in a previously published report by the senior author (RWH). Therefore, a total of 540 patients were evaluated for determination of the efficacy of anterior cervical plating with cortical allograft bone. Statistical significance was determined by chi(2) test. RESULTS: The fusion rates for one- and two-level ACDF with anterior fixation were 96 and 91%, respectively, compared with 90 and 72% for one- and two-level ACDF without anterior fixation. The observed increases in fusion rates for both one- and two-level procedures proved to be statistically significant (P < 0.05). There were no recorded infectious, neurological, or graft-related complications among the cohort treated with anterior cervical plating. Compared with the results for the cohort treated without anterior cervical plates, there was a statistically significant decrease in the graft-related complication rate with the application of plates (P < 0.001). Two patients who received plates were noted to have adjacent-segment degenerative changes that required surgical intervention. No hardware fractures were noted; however, one patient was noted to have a single displaced screw, without clinical consequences. CONCLUSION: The use of anterior cervical plating after one- and two-level ACDF with allograft cortical bone significantly enhanced arthrodesis. The improved fusion rate and negligible complication rate associated with anterior cervical plating are compelling factors justifying its use in the treatment of cervical spondylosis.     

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.     

颈前路减压融合钛板内固定治疗脊髓型颈椎病

目的讨论颈前路减压融合结合前路钛板内固定在脊髓型颈椎病治疗中的应用。方法回顾性分析62例脊髓型颈椎病选择颈前路减压（包括椎间盘切除和／或椎体次全切）融合及钛板内固定患者术后的治疗效果。所有患者术后随访2～4年,平均2．5年。结果术前及术后随访采用改良的JOA评分系统评价神经功能状况,术后神经功能恢复优良率为85．5％,椎间植骨融合率为100％。结论只要把握了手术时机和掌握了手术技巧,颈前路减压融合及钛板内固定是治疗脊髓型颈椎病安全而有效的方法。     

Comparison of allograft to autograft in multilevel anterior cervical discectomy and fusion with rigid plate fixation.

BACKGROUND CONTEXT: A relatively high pseudarthrosis rate is associated with multilevel anterior cervical discectomy and fusion (ACDF). Anterior plate fixation increases fusion rate in multilevel ACDF. A debate still exists between the effectiveness of allograft versus autograft in plated multilevel ACDF. PURPOSE: To determine the efficacy of allograft versus autograft in fusion rate and clinical outcome in patients undergoing two- and three-level ACDFs with rigid anterior plate fixation. STUDY DESIGN: A retrospective radiographic and clinical review to assess fusion, risk factors and clinical outcome of 80 consecutive patients who underwent ACDF with rigid anterior plate fixation involving two and three levels with either allograft or autograft. PATIENT SAMPLE: There were 45 patients (56%) who had autogenous iliac crest tricortical grafts and 35 patients (44%) who received tricortical allograft with an average age of 49 years who were treated by multilevel ACDF with rigid anterior plate fixation at a single institution. Thirty-three Peak polyaxial (Depuy-Acromed, Rayham, MA), 26 Orion (Sofamor-Danek, Memphis, TN), 16 Atlantis (Sofamor-Danek, Memphis, TN) and 5 Synthes (Paoli, PA) anterior cervical plating systems were used. All patients underwent ACDF (61 two-level, 19 three-level) by a Smith Robinson technique. All patients had burring of the end plates, 2-mm distraction of the motion segment and graft countersunk 2 mm from the anterior vertebral border. Anterior cervical plate with unicortical screw purchase was used in all cases. Segmental screw fixation was performed in 46 patients. Soft collars were worn postoperatively for 3 to 4 weeks. OUTCOME MEASURES: Follow-up lateral neutral, flexion and extension radiographs were used to assess fusion. The radiographs were reviewed by an independent blinded observer in assessing fusion grades between autograft versus allograft. Clinical outcomes were rated excellent, good, fair and poor based on Odom's criteria. METHODS: Fusion rate and postoperative clinical outcome were assessed in 80 patients who underwent two- or three-level ACDF with rigid anterior plate fixation. Additional risk factors were also analyzed. RESULTS: Radiographic fusion was assessed in all patients (mean, 16 months). Seventy-eight patients (97.5%) achieved solid arthrodesis. Pseudarthrosis occurred in two patients who had allograft for two-level and three-level fusions. Nonsegmental screws were used in the two-level nonunion case. Postoperative dysphagia developed in one two-level nonunion patient, and revision surgery was performed in the other nonunion three-level patient. Twenty-three patients were smokers, and 26 patients had work-related injuries. Clinical outcome (mean, 20 months) was excellent in 23, good in 48 and fair in 9 patients. No statistical significance was noted between demographics, history of tobacco use, graft-type, end plate preparation technique, intermediate segmental screws, plate-type, clinical outcome of fused and nonfused patients and presence of work-related injuries (p>.05). CONCLUSIONS: A high fusion rate of 97.5% was obtained for multilevel ACDF with rigid plating with either autograft or allograft. In this study, nonunion occurred in patients with allograft but this difference was not statistically significant. Fusion was obtained in 97.8% of patients with segmental screw fixation and 97.1% with nonsegmental screw fixation. Nonsegmental screw fixation may contribute to less than adequate stability and contribute to a higher rate of nonunion, but such effects could not be discerned from this study. Excellent and good clinical outcome was noted in 88.8% of the patients. Proper patient selection and meticulous operative technique is essential to obtain high fusion rates and optimal clinical outcome, which is more important than graft type.     

限制性与非限制性滑动钛板在颈椎前路手术中的应用

目的：对比分析限制性与新型非限制型滑动钛板在颈椎前路手术中的疗效及优缺点.方法：2000年3月～2004年12月连续诊治的58例颈椎伤病患者,其中应用限制性钛板27例,新型非限制性滑动钛板31例.对比分析两组患者的临床疗效、并发症、植骨融合率、椎体间高度及活动度变化.结果：平均随访28个月,两组患者术前、术后与随访时临床功能JOA评分均无显著性差异.影像学观察与测量非限制性钛板组1例假关节形成,1例可疑假关节形成,其余56例均达骨融合.术后两种内固定的单节段和双节段融合椎间高度均较术前有显著改善（P＜0.05）;随访显示在单节段融合,限制与非限制性内固定组椎间高度降低分别为0.5mm和1.6mm（P＜0.05）,而双节段融合,则分别为1.7mm和1.8mm（P＞0.05）.结论：在单节段融合时,限制性钛板在维持椎体间高度方面优于非限制性钛板;本研究尚不能得出新型非限制性滑动钛板临床疗效优干限制性钛板的结论.     

经前路椎间孔减压植骨固定治疗神经根型颈椎病

目的探讨经前路颈椎间孔减压植骨融合内固定术治疗神经根型颈椎病的疗效。方法回顾分析我院自2005年1月至2008年12月对21例神经根型颈椎病患者采用的经前路颈椎间孔减压植骨融合内固定术治疗。采用日本骨科学会（Japanese orthopaedics association,JOA）及视觉模拟评分（visual analogous scale,VAS）评分,观察术前、术后即刻、6个月、18个月疗效。结果共治疗观察21例患者,采用JOA评分,术前评分（8.50±1.25）分,随访终末评分（13.70±1.33）分,手术前后JOA评分具有显著性差异（P〈0.05）。VAS评分：术前评分（6.85±1.18）分,随访终末评分（2.15±1.30）分,手术前后VAS评分具有显著性差异（P〈0.05）。术后12个月植骨融合率为100%;术前Cobb角为10.3°（-5°～16°）,随访终末Cobb角为15.5°（0°～20.5°）;术后均无感染、喉返神经、喉上神经及椎动脉损伤,切口均一期愈合;无翻修手术者。结论经前路颈椎间孔减压植骨融合内固定术治疗神经根型颈椎病具有创伤小、减压直接、疗效确切的优点。     

颈前路减压植骨融合内固定术在治疗颈性眩晕中的作用

目的 探讨分析颈前路减压植骨融合内固定术在治疗颈性眩晕中的作用及其作用机制.方法 回顾分析了1998～2005年本治疗组采用颈前路减压植骨融合内固定术所治疗的伴有颈性眩晕的颈椎病患者32例.观察比较术前、术后颈椎正侧位及动力位X片和症状改善情况,并进一步通过颈性眩晕症状和功能评分法对患者术前及术后进行评定.结果 所有患者术前X片上都有不同程度的颈椎不稳或椎间盘突出现象,单节段不稳者9例,两节段者13例,三节段者7例.单节段椎间盘突出者10例,两节段者15例,三节段者7例.所有患者行颈前路减压植骨融合内固定术后获10～48个月的随访,平均26个月,术后有效率为87.5%,症状和功能评分分值有明显提高(均数由术前13.89提升到术后23.98),具有统计学意义(＜0.05),结论 颈前路减压植骨内固定术在治疗伴有颈性眩晕颈椎病中对颈性眩晕症状具有良好改善作用.     

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.     

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.     

颈椎前路减压钢板内固定治疗外伤性颈椎间盘突出症

目的　探讨颈椎前路减压钢板内固定对于外伤性颈椎间盘突出症的疗效。方法　对 2 5例 2 0 0 0年 3月～2 0 0 2年 5月行颈椎前路减压钢板内固定治疗外伤性颈椎间盘突出症患者的临床资料及手术治疗结果进行回顾性分析。结果　 19例获随访的患者在 12～ 15周内均获得牢固骨融合 ,无骨不连发生。神经功能改善依据JOA评定标准 ,优 (改善率 >75 % ) 18例 ,良 (改善率 5 0 %～ 74 % ) 3例 ,中 (改善率 2 5 %～ 4 9% ) 2例 ,无效 (改善率 <2 5 % ) 2例。结论　颈椎前路开窗减压或椎体次全切除减压、植骨钢板内固定是治疗外伤性颈椎间盘突出症行之有效的方法     

Anterior cervical allograft arthrodesis and instrumentation: Multilevel interbody grafting or strut graft reconstruction

This retrospective study evaluated a single surgeon's series of patients treated by multilevel cervical disc excision (two or three levels), allograft tricortical iliac crest arthrodesis, and anterior instrumentation. The objective of this retrospective study was to compare fusion success and clinical outcome between multilevel Smith-Robinson interbody grafting and tricortical iliac strut graft reconstruction, both supplemented with anterior instrumentation in the cervical spine. The incidence of nonunion for cervical discectomy and fusion varies widely depending on the number of disc levels involved, type of bone graft used, and whether the anterior grafting is supplemented with instrumentation. An alternative to multilevel interbody fusion is corpectomy and strut grafting, in which the incidence of nonunion has been reported to be 27% with autograft and 41% with allograft. Sixty-four consecutive patients who underwent allograft tricortical iliac crest reconstruction and anterior cervical plating were studied. The average follow-up was 39 months. There were 38 patients in the discectomy and interbody grafting group and 26 patients in the corpectomy and strut graft reconstruction group. Pseudoarthrosis occurred in 42% of the anterior cervical interbody fusion patients and 31% of the corpectomy patients. Nonunion in two-level interbody fusions occurred in 36% of the patients as compared to 10% for patients with one-level corpectomies; while 54% of patients with three-level interbody fusions and 44% of patients with two-level corpectomies were noted to have pseudoarthrosis. Higher percentages of nonunion were noted in multilevel interbody grafting than in corpectomy with strut grafting and when more vertebral levels were involved. These radiographic and clinical findings underscore the shortcomings of multilevel anterior cervical allograft reconstruction with plating. Corpectomy may be the preferred method when multiple disc levels are fused. In addition, anterior corpectomy affords decompression of significant osteophytes in a safer and quicker manner. In retrospective studies, there is a need for long-term follow-up before accurate statements can be made about the study population.     

前路钢板对两节段颈椎间植骨的运用价值

目的评价前路钢板对两节段颈椎间植骨融合的影响。方法46例两节段颈椎病患者,环锯法切除椎间盘、自体髂骨植骨,其中26例病人用了前路钢板内固定。术后复查X线片,了解植骨融合情况,并评价临床效果。结果26例运用钢板患者,全部获得骨性融合;20例单纯植骨病人,4例出现(20%)假关节,融合节段前凸丢失的度数较植骨融合组明显增大。获得植骨融合的病人,临床结果相似(P>0.05)。结论前路钢板系统增加两节段颈椎间植骨融合率、减少并发症。     

内固定结合外固定治疗严重下颈椎屈曲扭伤

目的探讨内固定结合外固定治疗严重下颈椎屈曲扭伤的效果。方法9例严重下颈椎屈曲扭伤患者采用前路椎间盘摘除、开放复位、植骨融合、锁定钢板内固定治疗。术后颈支具外固定3个月。结果9例均获随访,时间6~36个月,所有植骨间隙均融合,椎间隙及曲度保持正常。结论前路椎间盘切除,开放复位可降低脊髓损伤风险。内固定结合外固定促进植骨融合,重建颈椎稳定性,是治疗严重下颈椎屈曲扭伤的可靠方法。     

Posterior cervical fusion with rigid internal fixation

Rigid fixation of the posterior cervical spine offers definite advantages over conventional wiring techniques. These advantages are emphasized in certain high-risk groups of patients, including those with multiple-level traumatic instability, cervical deformities, and unresectable anterior tumor involvement. Early fusion with minimal external fixation is another important advantage. The focus of this article is the concept of rigid internal fixation of the posterior cervical spine and the application of specific techniques used to achieve this goal.     

颈前路短节段自体骨融合治疗颈椎病的前瞻性研究

目的探讨颈椎前路椎间短节段自体骨融合治疗颈椎病附加内固定的必要性。方法将81例需行颈前路短节段自体骨融合手术治疗的颈椎病患者随机分为单纯植骨及附加钛板内固定两组,随访55例患者,单纯植骨组23例,内固定组32例。随访时间(22±7)个月。采用JOA评分判定手术疗效, X线片判定融合效果、椎间高度变化和颈椎生理曲度变化。结果JOA评分改善率单纯植骨组68%,内固定组58% (P>0 05)。植骨融合率单纯植骨组93% ( 27 /29 ),内固定组100%。椎间高度单纯植骨组下降(0 7±1 0)mm,内固定组增加( 1 2±0 6 )mm (P<0 01 )。颈椎生理曲度单纯植骨组术后较术前减少(0 5±3 2)°, 内固定组术后较术前增加(2 7±7 8)°(P>0 05)。结论颈椎前路椎间短节段自体骨融合附加内固定治疗颈椎病有一定意义。     

Treatment of multilevel cervical fusion with cages

BACKGROUND: Multilevel cervical discectomy usually requires plate and screw fixation for maintaining the spinal curvature, and increasing the graft fusion rate. However, the use of plate and screw fixation may cause a few complications, such as screw breakage, screw pullout, esophagus perforation, and cord or nerve root injury. In this study, we try to use cages to replace plate function in multilevel cervical fusion. METHODS: From January 1997 to June 2001, there were 180 consecutive cases of multilevel cervical degenerative disease. We randomized them into three groups: Group A (60 patients) underwent anterior discectomy and polyetheretherketone (PEEK) fusion, Group B (50 patients) underwent anterior discectomy, autogenous iliac crest graft (AICG) fusion and plate fixation, and Group C (70 patients) underwent anterior discectomy and AICG only. X-ray of cervical spine was taken every 3 months until fusion was complete. Spinal curvature was measured by lateral view of X-ray. The functional and working status were evaluated by Prolo scale. Blood loss and operation time were recorded, respectively. RESULTS: The total complication rates were 3.3%, 16%, and 54.3% in Groups A, B, and C respectively. The graft complications were evaluated by radiographic findings (graft collapse, nonunion, or dislodged graft). However, only 37.1% of patients (13/35) with graft complications had clinical symptoms (severe neck pain, radicular pain, or neurologic deficits). The fusion rate was better, and the time to fusion was sooner in Groups A and B than Group C, p < 0.001 (chi(2) test). PEEK cage is statistically better than plating group in total complications, p < 0.05. Graft collapse and nonunion were the major graft complications in Group C (AICG without plating). Screw pullout, and screw breakage were the main causes of plating complication. Blood loss was minimum in Group A, p < 0.05. Spinal lordosis increased by a mean of 4.61 +/- 2.93 mm and 1.68 +/- 5.02 mm in Groups A and B, respectively, but spinal kyphosis increased by a mean of -2.09 +/- 4.77 mm in Group C. Group A had a statistically better Prolo scale than Group C, p < 0.0001. CONCLUSIONS: Both PEEK cage without plating and AICG with plating are good methods for interbody fusion in multilevel cervical degenerative diseases. They increase spinal lordosis and graft fusion rate, and cause fewer surgical complications. However, PEEK cage is preferred in our study for multilevel fusion, because it has the fewest complication rates and the least amount of blood loss.