应用颈椎前路动态ABC钢板促进颈椎椎体间融合

目的观察颈椎前路动态ABC钢板促进颈椎椎体间植骨融合的疗效。方法对40例患者（68个节段）行颈椎前路椎间盘摘除、椎体间自体髂骨植骨、ABC钢板内固定术。术后观察ADL评分，颈椎曲度、椎体间融合及融合植骨块下沉情况。结果40例均获随访，时间12—44（22．17±8．33）个月。ADL评分术前2～13（7．92±3．07）分，术后8—17（13．94±2．48）分，改善明显。术后无钢板、螺钉断裂或松动现象发生。39例颈椎生理性前凸获得良好改善，仅1例术后3个月融合椎体邻近节段发生反曲，患者颈部无不适症状。68个融合节段中，67个节段6个月内融合，1个节段延迟至术后12个月时方融合。术后3个月内，单节段融合植骨块下沉平均（1．21±0．54）mm，2节段平均（2．01±0．87）mm，3节段平均（2．97±0．82）mm。3个月后各节段下沉不再明显。结论应用动态ABC钢板可以降低植骨后相关并发症的发生，有效避免静态钢板造成的应力遮挡，从而促进颈椎椎体间的融合。     

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。     

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.     

Anterior cervical discectomy with hydroxylapatite fusion

The outcome of microscopic anterior cervical discectomy with iliac crest interbody fusion in a group of 75 patients was compared with that of microscopic anterior cervical discectomy with synthetic hydroxylapatite fusion in a group of 84 patients. The rate of relief of myelopathy (70%) was similar in both groups, but those who underwent synthetic fusion had better long-term relief of radiculopathy, less need for a second operation at the same or an adjacent level, no resorption of the bone plug, comparable spinal alignment and stability, and the elimination of complications at the iliac crest donor site. The data suggest that hydroxylapatite fusion may be equal or superior to autologous iliac crest interbody fusion for anterior cervical disc surgery.     

A prospective clinical comparison of rectangular titanium cages and iliac crest autografts in anterior cervical discectomy and fusion

The complications of autogenous bone grafting cause spinal surgeons to seek alternative methods for cervical spinal fusion. This prospective study was conducted to evaluate the safety and efficacy of rectangular titanium cages as compared to the widely performed iliac crest autograft fusion. Thirty-six patients with cervical disc disease in whom an anterior cervical approach was indicated for discectomy were included in a prospective controlled study protocol with 1-year follow-up. The first 18 consecutive patients received iliac crest autograft, while the next 18 received rectangular titanium cages. According to Odom's criteria, 15 of 18 (83%) patients in both groups experienced good to excellent functional recovery. According to the patient satisfaction index, 17 of 18 (94%) in both groups were satisfied. There were no significant differences in neck or arm pain. Fusion was present after 1 year in 16 of 18 (89%) patients in the iliac crest autograft group and 15 of 18 (83%) in the rectangular titanium cage group. In the autograft group, one case of pseudarthrosis was present, and marked hip pain was observed in four patients. There were no implant-related complications in the cage group. The authors conclude that titanium cages in anterior cervical discectomy constitute a safe and efficient alternative to iliac crest bone autograft.     

Anterior cervical interbody fusion with rhBMP-2 and tantalum in a goat model.

BACKGROUND CONTEXT: Tricortical autogenous iliac crest has long served as the gold standard for arthrodesis after cervical discectomy. The added morbidity resulting from bone graft harvest may be eliminated by the use of a biocompatible synthetic bone graft substitute with osteoconductive abilities, and when used with an osteoinductive agent, such as recombinant bone morphogenic protein (rhBMP)-2, it may facilitate arthrodesis similar to autograft. PURPOSE: To determine by radiographic and histologic analysis whether tantalum with and without rhBMP-2 can facilitate bony ingrowth and arthrodesis in an animal model. STUDY DESIGN/SETTING: Single-level anterior cervical discectomy and fusion was performed using a tantalum bone graft substitute with and without rhBMP-2 in a previously established goat model for anterior cervical fusion. METHODS: Eight goats underwent single-level anterior cervical discectomy and stabilization with a porous tantalum implant. There were four goats in each experimental group. Group A underwent anterior cervical stabilization with tantalum alone, whereas in Group B rhBMP-2 was added to the tantalum implant. The goats were sacrificed at 12 weeks, and their cervical spines were removed for histologic and radiological analysis. RESULTS: Only one of four goats in Group A had any bony ingrowth into the tantalum. Three of four goats in Group B demonstrated bony ingrowth. The average extent of bony ingrowth at the perimeter of the tantalum in Group A was 2.5% compared with 12.5% in Group B. Similarly, the volume of bony ingrowth within the tantalum was 2.5% in Group A and 10% in Group B. The difference was not statistically significant. CONCLUSIONS: The data in this pilot study suggest that tantalum may function as a synthetic osteoconductive bone graft substitute. The addition of rhBMP-2 may facilitate osteoinduction within a synthetic osteoconductive implant. The sample size in this study was too small for statistical significance. The present animal model as used in this study was inadequate for cervical arthrodesis where rigid implant fixation is desired.     

Autograft versus allograft in degenerative cervical disease.

Cervical spondylosis, common among people older than 50 years, may produce symptoms of cervical radiculopathy, myelopathy, or both. When patients with degenerative cervical disease require surgery, an anterior decompression of the neural elements and reconstruction of the anterior column with allograft or autograft is common. Allograft incorporates more slowly and less completely than autogenous bone graft, although harvest of autograft from the anterior iliac crest or the middle 1/3 of the fibula may be associated with postoperative morbidity. Overall, higher rates of fusion have been reported with autograft than allograft. However, similar fusion rates have been reported among nonsmokers having single-level anterior cervical interbody fusions. For patients requiring multilevel reconstruction surgery, fusion rates of approximately 100% have been achieved using autogenous strut grafts from the iliac crest and fibula, with a lower rate of incorporation for fibula allograft. The potential for a patient with a nonunion requiring additional operative treatment must be weighed against the potential for graft-related complications when choosing between autograft and allograft for anterior cervical reconstruction.     

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.     

Three- and four-level anterior cervical discectomy and fusion with plate fixation: a prospective study

STUDY DESIGN: A prospective study of 15 patients who underwent modified Smith-Robinson anterior cervical discectomy and fusion at three or four operative levels stabilized with an unicortical anterior plate. OBJECTIVES: To provide medium-term follow-up data on the surgical success and patient outcome of three- and four-level anterior cervical discectomies and fusions and to determine the effect that plate fixation has on the results. SUMMARY OF BACKGROUND DATA: The success of arthrodesis for anterior cervical fusion depends on several factors, including the number of surgical levels. The arthrodesis rate and outcome for patients having three- and four-level discectomy and fusion procedures is disappointing. Internal fixation putatively improves these parameters. METHODS: Fifteen patients (average age, 51 years; range, 35-77), were observed for an average of 42 months (range, 25-73) All had an anterior discectomy, burring of the endplates, placement of an autogenous tricortical iliac crest graft at three (12 patients) or four (3 patients) levels, and application of a Cervical Spine Locking Plate. All patients had follow-up office visits with examinations and radiographs. Radiographic union, postoperative pain relief, and neurologic recovery were evaluated. RESULTS: Solid arthrodesis was achieved at all levels in only 7 (47%) of the 15 patients after a single procedure. Of the 8 patients with pseudarthrosis, 3 had sufficient pain to necessitate revision surgery (with pain relief in two), 1 had pain without further surgery, and 4 no pain. Of the 7 with solid fusion, 3 had persistent pain, and 4 had none. Two in this group had a second procedure. All 4 patients with preoperative myelopathy improved, and 10 of the 11 with radiculopathy had resolution of arm symptoms. CONCLUSIONS: Three- and four-level modified Robinson cervical discectomy and fusion results in an unacceptably high rate of pseudarthrosis. The Cervical Spine Locking Plate alone does not appear to improve the arthrodesis rate.     

Does donor site reconstruction following anterior cervical surgery diminish postoperative pain?

Many attempts have been made at donor site reconstruction to reduce postoperative pain following anterior cervical surgery. This study is a comparative analysis of the outcome of 46 patients undergoing single-level anterior corpectomy and fusion using iliac crest autograft performed by one surgeon (N.E.E.). Twenty-three patients had no donor site reconstruction, whereas the more recent 23 patients had iliac crest reconstruction using a MacroPore sheet (MacroPore, Inc., San Diego, CA) and Inductive Conductive Matrix (ICM, Sofamor Danek, Memphis, TN). Bodily Pain, assessed on the Short Form-36, obtained up to 12 months postoperatively, failed to demonstrate better pain relief following donor site reconstruction. Multiplanar CT studies obtained 6 months postoperatively documented 100% donor site fusion for the 23 reconstructed patients. Although iliac crest reconstruction failed to reduce Bodily Pain, it did result in 100% fusion.     

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。     

前路三节段椎间盘切除减压治疗颈椎病的近期疗效分析

目的 分析颈前路三节段椎间盘切除减压术治疗颈椎病的临床与影像学结果.方法 2002年10月至2007年1月,对23例颈椎病患者行颈前路连续三节段椎间盘切除减压、自体髂骨植骨、钢板内固定术,男15例,女8例;年龄32～66岁,平均51.4岁.通过分析术前及随访时JOA评分,观察其改善率,并记录术后颈部症状及Odom分级.测量术前、术后1周及末次随访时颈椎侧位X线片,观察颈椎融合节段曲度(Cobb角).在末次随访时,观察融合节段的融合情况以及邻近节段退变情况.结果 随访时间11～48个月,平均19.8个月.20例脊髓型颈椎病患者术前JOA评分(11.1±1.0)分,术后3个月(14.6±1.0)分,两者比较差异有统计学意义,平均改善率62%.3例神经根型颈椎病患者末次随访时,2例症状全部消失,1例左侧三角肌肌力由术前2级恢复至4级.术后Odom分级:优15例,良4例,一般4例.术后17.4%(4/23)的患者颈部仍有症状.植骨融合率100%.术前Cobb角为3.7°,术后1周为10.8°,末次随访为10.4°.未观察到邻近节段病变.无神经系统及与内固定物相关的并发症.结论 颈前路三节段椎间盘切除减压、自体髂骨植骨融合、钢板内固定术可以获得很高的植骨融合率.     

Does anterior plating maintain cervical lordosis versus conventional fusion techniques? A retrospective analysis of patients receiving single-level fusions

A retrospective review of medical records and radiographs of patients receiving anterior cervical discectomy and fusion (ACDF) without anterior plating and with anterior plating was performed. The objective of the study was to determine whether a difference exists in cervical lordotic alignment between subjects undergoing single-level ACDF with and without anterior cervical plating instrumentation for symptomatic cervical disc disease. Collapse or settling of grafted bone into the vertebral endplates with resulting kyphotic deformity of the cervical spine is a commonly described complication of anterior discectomy and fusion. Despite the increasing use of instrumentation for the treatment of cervical spine injuries and degenerative conditions, little is known regarding lordotic alignment of the cervical spine in patients who receive plating instrumentation compared with conventional fusion without plating. Accumulating evidence suggests that plating is superior to non-plating techniques in patients with multiple level cervical disc lesions in regard to fusion, return to work rates, and complication rates; however, little is known about maintenance of lordotic curve alignment in single- and multiple-level procedures. Neutral lateral cervical radiographs of 57 patients who underwent single-level ACDF between 1994 and 1999 with anterior screw plates (n = 26), and conventional single-level fusion without anterior screw plates (n = 21) were retrospectively assessed. Measurements were made on weight-bearing lateral cervical radiographs to assess overall sagittal spinal alignment and intersegmental sagittal alignment at the surgical site before surgery, immediately after surgery, 4 to 12 weeks after surgery, and 12+ months after surgery. The average magnitude of overall lordosis measured between C2 and C7 decreased 4.2 degrees in the non-plated group, while being preserved in the plated group. This finding did not reach statistical significance in the long-term follow-up. At the surgical site, the segmental contribution to lordosis decreased an average 2.5 degrees in the non-plated group versus an increase of 5.67 degrees in the plated group, and this finding was statistically significant between groups measured at all pre- and postoperative visits (p < 0.01). On average, the plating procedure resulted in preserving overall lordosis while increasing the magnitude of segmental lordosis at the surgical site. In comparison, the conventional method resulted in a net loss of overall lordosis and segmental lordosis at the surgical site.     

颈前路减压cage融合术与自体髂骨块植骨钛板内固定术治疗脊髓型颈椎病的中期疗效

目的:观察颈椎前路减压cage植骨融合术与颈椎前路减压自体髂骨块植骨融合钛板内固定术治疗脊髓型颈椎病的中期临床疗效。方法:2001年1月～2006年4月128例脊髓型颈椎病患者按照手术方式分为A、B两组,A组61例患者采用前路减压单纯PEEK cage植骨融合术治疗,其中病变节段与手术节段均为单节段22例,双节段39例;B组67例采用颈椎前路减压自体髂骨块植骨融合钛板内固定术,其中单节段27例,双节段40例。观察手术前后JOA评分、椎间高度和颈椎曲度情况。结果:A组手术时间为58.1±1.4min,术中出血量为42.4±2.0ml,B组分别为72.0±5.3min、82.7±3.9ml,两组比较差异有统计学意义(P<0.05)。A组23例(39.3%)出现一过性咽部不适,1例硬脊膜破裂,2例cage塌陷、移位;B组49例(73.1%)出现一过性咽部不适,1例硬脊膜破裂,5例髂骨供区痛,2例钉板松动。每组患者术后JOA评分、椎间高度和颈椎曲度均较术前明显改善(P<0.05),A、B组术后JOA评分改善率分别为(82.30±6.61)%和(83.80±4.42)%,组间比较差异无统计学意义(P>0.05)。随访24～60个月,平均36个月,末次随访时A、B组椎间融合率分别为95.2%和96.3%,两组比较差异无统计学意义(P>0.05);末次随访时每组JOA评分、椎间高度和颈椎曲度与术后比较差异无统计学意义(P>0.05)。术前、术后和末次随访时JOA评分、椎间高度和颈椎曲度两组比较差异无统计学意义(P>0.05)。结论:颈椎前路减压cage植骨融合术与颈椎前路减压自体髂骨块植骨融合钛板内固定术治疗脊髓型颈椎病的中期疗效均较好,但前者手术方法简单、近期并发症少。     

两种前路减压融合术治疗颈椎间盘突出症的比较

目的对前路颈椎间盘切除减压的碳纤维椎间融合器(cage)植入术与自体髂骨块植骨加钛板固定术治疗单节段颈椎间盘突出症(CDH)进行临床疗效及影像学评估。方法需要手术治疗的单节段CDH患者60例,其中前路减压cage植入术31例,自体髂骨块植骨加钛板固定术29例。术前、术后及随访期间摄X线片,比较两组病例的手术时间、术中出血量、术后并发症、症状改善率、融合时间、融合率、融合节段椎体间高度的维持情况。结果cage植入术较自体髂骨块植骨加钛板固定术手术时间短,出血少(P<0.01)。两组融合节段椎体间高度较术前均明显改善(P<0.01)。两组间症状改善率、融合率无统计学意义(P>0.05)。cage植入术较自体髂骨块植骨加钛板固定术并发症少。结论cage植入术和自体髂骨块植骨加钛板固定术都是前路减压治疗单节段CDH的重要而有效的方法。而cage植入术在减小手术创伤的同时,可以获得同样的临床效果,是治疗单节段CDH理想的术式之一。     

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.     

Delayed iliac crest autograft fractures following plated single-level anterior cervical corpectomy with fusion

Recurrent cervical pain following single-level plated anterior corpectomy with fusion signaled delayed mid-iliac crest autograft fractures in four of 56 patients. Single-level anterior corpectomy with fusion used 15 fixed plates (Sofamor Danek) and 41 dynamic ABC plates (Aesculap). Patients in the fixed-plate and dynamic-plate groups averaged 46 and 48 years of age, respectively. Fusion was confirmed on both dynamic radiograph and two-dimensional CT studies an average of 4.5 months postoperatively. Two (13%) fixed-plated patients developed mid-iliac crest strut fractures 1 and 2 years postoperatively, whereas two (5%) dynamic-plated patients showed similar fractures 6 and 9 months following surgery. Immobilization in CTO orthoses resulted in fusion in one case, whereas three patients required secondary posterior wiring/fusion. Recurrent pain signaled delayed autograft strut fractures in four of 56 patients undergoing plated single-level anterior corpectomy with fusion.     

A novel source of cancellous autograft for ACDF surgery: the manubrium

There are a variety of techniques and biologic options when performing interbody fusion during an anterior cervical discectomy and fusion (ACDF). Autologous graft provides high rates of fusion; however, complications associated with donor site morbidity from the iliac crest have prompted some surgeons to use alternative graft material. Ten patients (8 men, 2 women) with cervical radiculopathy underwent single-level ACDF with plate fixation, titanium mesh cage, and cancellous autograft from the manubrium. Cancellous bone was obtained through a cortical window on the anterior aspect of the manubrium through a 2-cm transverse incision. A minimum 1-year clinical and radiographic follow-up for all patients evaluated fusion rates, donor site morbidity, and patient satisfaction. All patients had immediate postoperative resolution of radicular symptoms and radiographic evidence of solid fusion within 3 months. No patient complained of donor site pain and narcotic pain medication was not required after discharge. No complications associated with the manubrium donor site were noted; however, 1 female patient was dissatisfied with its cosmetic appearance. The manubrium is an effective, safe, and technically facile source of autologous bone graft that yields high fusion rates and patient satisfaction in contemporary ACDF surgery. This new technique to obtain cancellous graft from the manubrium combines the advantages of autologous bone without the morbidity of iliac crest harvest.     

Treatment of cervical pseudarthrosis after Smith-Robinson procedure with Halifax clamp fixation

Treatment of pseudarthrosis of the cervical spine has been debated extensively with various solutions being proposed. This article reviews 18 cases of pseudarthrosis after attempted anterior cervical discectomy and fusion with tricortical iliac crest autograft using the Smith-Robinson method. All cases were subsequently treated with posterior fusion using cancellous iliac autograft and fixation with Halifax clamps. All cases showed radiographic union at the 6-month follow-up. There were no complications related to the application of the device. One device showed loss of fixation in the follow-up period. The Halifax clamp is technically simple to apply and can be done safely. High success rates in obtaining fusion after failed anterior discectomy and fusion in the cervical spine and ease of application make this method of posterior fixation and fusion an attractive alternative for dealing with pseudarthrosis.     

Cervical kinematics after fusion and bryan disc arthroplasty

INTRODUCTION: Disc arthroplasty has been shown to provide short-term clinical results that are comparable with those attained with traditional anterior cervical discectomy and fusion. One proposed benefit of arthroplasty is the ability to prevent or delay adjacent level operations by retaining motion at the target level and eliminating abnormal adjacent activity. This paper compares motion parameters for single-level anterior cervical discectomy and fusion and disc replacement patients at the index level and adjacent segments. METHODS: Radiographic data from patients enrolled in a prospective, randomized clinical trial were selected for kinematic assessment of cervical motion. All patients received either a single-level fusion with allograft and anterior cervical plate (Atlantis anterior cervical plate, n=13) or a single-level artificial cervical disc (Bryan Cervical Disc prosthesis, n=9) at either C5/C6 or C6/C7. Flexion, extension, and neutral lateral radiographs were obtained preoperatively, immediately postoperatively, and at regular intervals up to 24-month time points. Cervical vertebral bodies were tracked on the digital radiographs using quantitative motion analysis software (QMA, Medical Metrics) to calculate the functional spinal unit motion parameters including range of motion (ROM), translation, and center of rotation. If visible, the functional spinal unit parameters were obtained at the operative level, and also the level above and the level below. RESULTS: As expected, significantly (P<0.006 at 3, 6, 12, and 24 mo) more flexion/extension motion was retained in the disc replacement group than the plated group at the index level. The disc replacement group retained an average of 6.7 degrees at 24 months. In contrast, the average ROM in the fusion group was 2.0 degrees at the 3-month follow-up and gradually decreased to 0.6 degrees at 24 months. The flexion/extension ROM both above and below the operative level was not statistically different for the disc-replaced and fusion patients, however, mobility increased for both groups over time. The anterior/posterior translation that occurs with flexion/extension motion remained unchanged for the disc replacement group at the level above the target disc preoperatively and postoperatively. In contrast, the translation increased for the level above the fusion. At the 6-month follow-up, the increase in translation was significantly greater for patients that were fused (P<0.02) than for patients that received a disc replacement. This change was not significant at 12 months. DISCUSSION: Previous studies have shown the Bryan disc to maintain mobility at the level of the prosthesis. The long-term clinical benefit of maintenance of motion is postulated to be the ability to delay or avoid adjacent level operations. This study reveals that there is no difference in flexion/extension ROM at the level above and below either a fusion or Bryan arthroplasty. There is, however, an increase in anterior/posterior translation at the cephalad adjacent level in patients with arthrodesis while the Bryan arthroplasty retains normal translation for the same amount of flexion/extension at the adjacent level. CONCLUSION: The Bryan disc may delay adjacent level degeneration by preserving preoperative kinematics at adjacent levels.