Implantation of a distractible titanium cage after cervical corpectomy: technical experience in 20 consecutive cases

Summary Background. This prospective observational study was undertaken to investigate the advantages, the safety, and the drawbacks of reconstructing a cervical corpectomy with a distractible corpectomy cage. According to the author’s literature search, this is the second clinical report on a distractible cervical corpectomy cage. Method. 20 consecutive patients underwent a single- or multi-level cervical corpectomy for spondylotic myelopathy, traumatic fracture, or tumor. The corpectomy defect was reconstructed by means of a distractible titanium cage, and local bone from the corpectomy was layed around the cage for fusion. An anterior cervical plate and/or a posterior lateral mass or pedicle screw fixation was added in all patients. The average follow-up was 14 months, and all patients had at least 12 months of follow-up. Findings. No hardware failure occurred in any of the patients. Construct stability was achieved in 19 out of 20 patients (95%) at 12 months postoperatively. The mean regional lordosis was 1° preoperatively, 9° postoperatively, and 7° at the follow-up. Mean neck pain on a VAS was 3.9 preoperatively, and 2.6 at 12 months. There were three perioperative complications: transient neurological worsening in one patient, one transient vocal cord paralysis, and persistent dysphagia in one patient. Conclusion. A single- or multi-level cervical corpectomy can be safely and effectively reconstructed by a distractible titanium cage and local bone graft in combination with anterior cervical plating and/or posterior lateral mass/pedicle screw fixation. Potential advantages of this technique are an unforced cage insertion in its non-distracted position, press-fitting the cage into the corpectomy defect through cage distraction, correction of kyphosis or preservation of local lordosis through cage distraction, and the absence of donor site morbidity. However, the stability rate in the current series did not exceed the fusion rates of auto- or allografts.     

Cervical reconstruction techniques. After adequate selection of the patient report of a series of 34 patients treated with winged expandable cages

After single or multilevel cervical corpectomy for the treatment of different diseases, many surgical options have been proposed over the years. As a single device, a winged expandable titanium cage (WETC) has been developed. We report the use of this device and our clinical results at 24 months of follow-up in a prospective series of 34 patients who underwent single or multilevel corpectomy for the treatment of cervical spondylosis. Thirty-four consecutive patients underwent single or multilevel cervical corpectomy followed by the insertion of a WETC for the treatment of cervical spondylosis at Department of Neurology and Psychiatry “Sapienza” University of Rome, Italy, from May 2011 to May 2013. Patients affected by cervical spondylosis with cervical lordosis >0° were included. Patients affected by cervical lordosis <0°, osteoporosis, or other cervical diseases were excluded. The mean postsurgical Nurick’s grade was significantly lower than the mean presurgical Nurick’s grade (mean = 0.98 for postsurgical Nurick’s grade and mean = 2.42 for presurgical Nurick’s grade). Four patients (11.7 %) presented subsidence respectively of 1, 2, 2, and 3 mm at 24 months of radiological follow-up. Postoperative complications occurred in five patients (14.7 %). Our case series at 24 months of follow-up demonstrates that the use of a WETC obtains good clinical results after single or multiple corpectomy in patients not affected by osteoporosis who do not require cervical lordosis correction. During the insertion of the device, an adequate preparation of the end plates is suggested and their over distraction should be avoided.     

A new technique for anterior cervical pedicle screw implantation

Objective: To introduce and evaluate a new technique, anterior pedicle screw implantation, for anterior cervical reconstruction. Methods: Seven patients (five men and two women) with an average age of 65 years were included in this group. After carefully preparation, anterior pedicle screws were implanted under fluoroscopy in all patients. The position of the anterior pedicle screws was evaluated three days postoperatively by X‐ray and CT imaging. The mean recovery rate as assessed by the Japanese Orthopaedic Association (JOA) score was recorded at final follow‐up. Results: A total of fourteen anterior pedicle screws were implanted in our group. The average follow up period was 8 months. The mean JOA score was 12.5 preoperatively and 14.8 postoperatively. The mean improvement in the JOA score was 50.5% at final follow‐up. The average local alignment improved from 4.0 of kyphosis preoperatively to 6.5 of lordosis at final follow‐up. Early bony union was observed in four cases that were followed up for more than 3 months. There were no serious complications. No “pedicle perforation” was observed in any of the fourteen anterior pedicle screws, whereas one screw exposure occurred. Conclusion: Anterior cervical pedicle screw implantation is a feasible method for selected cases. It provides another choice for strong anterior cervical reconstruction.     

Anterior corpectomy with iliac bone fusion or discectomy with interbody titanium cage fusion for multilevel cervical degenerated disc disease

STUDY DESIGN: Clinical and radiologic study evaluating the outcome after anterior corpectomy with iliac bone fusion compared with discectomy with interbody titanium cage fusion for multilevel cervical degenerated disc disease. OBJECTIVES: To investigate the safety and effectiveness of interbody titanium cage with plate fixation in multilevel postdiscectomy fusion. SUMMARY OF BACKGROUND DATA: The operation for segmental multilevel cervical degenerated disc disease remains controversial. Data on safety and efficacy of titanium cages in multilevel postdiscectomy fusion are rarely available. We investigated the safety and effectiveness of interbody fusion cages with plate fixation and compared the clinical and radiographical results between anterior corpectomy and iliac bone fusion with plate fixation and multilevel discectomy and cage fusion with plate fixation. METHODS: Sixty-two patients were treated with either a multilevel discectomy and cage fusion with plate fixation (27 patients, group A) or an anterior corpectomy and iliac graft fusion with plate fixation (35 patients, group B). We evaluated the patients for cervical lordosis, fusion status, and stability 24 months postoperatively on the basis of spine radiographs. The patients' neurologic outcomes were assessed by the Japanese Orthopedic Association (JOA) scores. Neck pain was graded using a 10-point visual analog scale. RESULTS: Both groups A and B demonstrated a significant increase in the JOA scores (preoperatively 11.1+/-2.1 and 10.4+/-3.5, postoperatively 14.3+/-2.4 and 13.9+/-2.1, respectively) and a significant decrease in the visual analog pain scores (preoperatively 8.5+/-1.1 and 8.7+/-1.5, postoperatively 2.9+/-1.8 and 3.0+/-2.0, respectively). However, there was no significant difference between groups A and B. Both groups A and B showed a significant increase in the cervical lordosis after operation and reached satisfactory fusion rates (96.3% and 91.4%, respectively). Three patients (two 2-level corpectomies and one 3-level corpectomy) had construct failures that required a second operation. Eight of 35 patients who underwent iliac bone fusion had donor site pain. The hospital stay in group A was significantly shorter than that in group B (P=0.022). CONCLUSIONS: Either a multilevel discectomy and cage fusion with plating or a corpectomy and iliac bone fusion with plating provides good clinical results and similar fusion rates for cervical degenerative disc disease. However, absence of donor site complications and construct failures and shorter hospital stay make the multilevel discectomy and cage fusion with plate fixation better than corpectomy and strut graft fusion with plate fixation.     

Expandable titanium cages for anterior column cervical reconstruction and their effect on sagittal profile: a review of 48 cases

Background

Expandable cervical cages have been utilised successfully to reconstruct the cervical spine for various conditions. However, to date there are only limited data on their influence on cervical sagittal profile. In this retrospective study, we present our experience with performing anterior cervical corpectomy in one or two levels using expandable titanium cages in order to achieve stable reconstruction and restoration of cervical lordosis.

Methods

A case series of data from 48 consecutive patients (20 men, 28 women; mean age 61 years) operated upon in a 5-year-period is retrospectively reviewed. Standard anterior single- or two-level cervical corpectomy, fusion and spinal reconstruction were performed, including placement of an expandable titanium cage and an anterior cervical plate. The mean follow-up was 23 months (range, 8–42 months). Outcome was measured by clinical examinations and visual analogue scale (VAS) scale; myelopathy was classified according the Nurick grading system. Radiographic analysis comprised several parameters, including segmental Cobb angle, cervical lordosis, subsidence ratio and sagittal cage angle. Computed tomography was done 1 and 2 years after surgery; cervical spine radiographs were obtained 3, 6, 12 and 24 months after surgery.

Results

In 38 patients (79 %) osseous fusion or stability of construct could be demonstrated in the 2-year follow up examination. The mean restoration of segmental Cobb angle as well as cervical lordosis amounted to 7.6° and 5.4° respectively, both being statistically significant. Furthermore, a profound correction (10° or more) of the sagittal cervical curve was shown in 15 patients.

Conclusion

Regarding the restoration of the physiological sagittal cervical profile, expandable cervical cages seem to be efficient and easy to use for cervical spine reconstruction after anterior corpectomy. Donor-site-related complications are avoided, fast and strong reconstruction of the anterior column is provided, resulting in satisfactory fusion rates after 2 years.     

后路减压固定治疗伴椎间盘突出的下颈椎骨折脱位

目的 探讨经后路减压复位椎弓根螺钉固定治疗伴椎间盘突出的下颈椎骨折脱位的疗效。方法 对2009年6月至2012年9月采用经后路减压复位椎弓根螺钉固定治疗伴椎间盘突出的下颈椎骨折脱位18例病例进行回顾性分析。结果 所有手术均顺利完成,共置入椎弓根螺钉88枚,平均手术时间为2.7 h,平均出血量为400 mL。所有患者均未因神经功能恶化或椎间盘突出而需要再次行前路手术。18例患者术后平均随访15个月。复查X线片、CT片示骨折脱位复位良好,椎间隙高度及颈椎生理弧度得到恢复。末次随访时,除10例Frankel A级患者以外,其余患者Frankel分级提高1～2级。结论 经后路减压复位椎弓根螺钉固定可适用于伴椎间盘突出的下颈椎骨折脱位,后路手术有利于复位,椎弓根螺钉技术具有良好的生物力学稳定性,能有效地恢复和维持颈椎的序列,同时避免了前路手术。     

经后路椎体次全切除、钛网及椎弓根钉重建术治疗严重胸腰椎骨折

目的 探讨经后路椎体次全切除、钛网及椎弓根钉重建术治疗严重胸腰椎骨折的临床价值.方法 2006年1月至2007年8月,对36例严重胸腰椎骨折患者采用本术式治疗.按AO骨折分型,均为A3亚型;术前神经功能ASIA分级:A级8例,B级16例,C级8例,D级4例.手术采用后正中入路,显露伤椎及其上、下邻椎的椎板、关节突及椎弓根钉进钉点,在上、下邻椎内置入椎弓根钉,通过椎弓根内同定试行撑开复位或矫正脊柱序列,临时固定.切除伤椎椎板及相关的关节突间关节,切除一侧或双侧椎弓根内缘创建后外侧工作通道,然后通过后外侧工作通道用骨刀对伤椎进行适当的壳内次全切除,并将钛网置人伤椎椎体次全切除后的骨缺损区,透视满意后加压椎弓根钉使钛网牢固.通过比较术前、术后和随访时X线及CT片上Cobb角和骨块椎管占位比例来评价后凸畸形矫正情况、椎管减压程度及植骨融合情况.结果 术后随访12～24个月,平均18个月.所有患者在术后12个月时ASIA神经功能分级均有1级或1级以上的恢复.术后12个月时X线和CT片显示减压和复位效果满意.脊柱序列恢复正常,植骨融合率为97.3%.35例患者无继发性后凸畸形.1例患者出现钛网塌陷及后凸畸形.结论 经后路椎体次全切除、钛网及椎弓根钉重建术可结合前后路手术优势,一个切口一次完成减压、复位、固定、融合,重建三柱的稳定性;但尚须大宗病例的积累及长期随访验证.     

多节段腰椎骨折的临床治疗分析

[目的]复习一组应用TSRH-3D椎弓根螺钉系统复位并椎弓根内固定治疗多节段腰椎骨折病人的临床资料,探讨该技术对腰椎骨折复位及内固定的治疗效果及远期疗效。[方法]本组18例,应用TSRH-3D椎弓根螺钉系统复位并椎弓根内固定治疗多节段腰椎骨折,均于伤后4 h～2 d内手术,所有患者均得到随访,随访时间15～32个月,平均23个月。均于术前、术后、末次随访时拍摄脊柱正侧位X线片、CT片。[结果](1)本组12例(67%)为高处坠落伤,5例(28%)为车祸伤,1例(5%)为挤压伤;(2)脊柱活动改善率为67%;腰背痛改善率为94%;下肢疼痛改善率为78%;(3)与术前相比,伤椎前缘高度平均矫正59.2%,平均丢失5.2%(P0.01);Cobb′s角平均矫正19.5°,平均丢失5.4°(P0.01)。[结论]采用TSRH-3D椎弓根螺钉内固定系统治疗多节段腰椎骨折对损伤节段可有满意的复位及内固定效果,有利于恢复脊柱伤椎高度、生理弧度和神经功能以及消除腰腿痛,有较好的远期疗效。     

一期经后路三柱重建技术治疗胸腰椎爆裂骨折

目的 探讨严重胸腰椎爆裂骨折应用经后路进行脊柱三柱重建技术的临床效果.方法 对24例胸腰椎爆裂骨折采用经后路椎体次全切除、钛网置入及椎弓根钉重建术治疗.采用Frankel评定标准评定术后神经功能恢复情况.通过影像学变化评价后凸畸形矫正情况和椎管减压程度.结果 本组获随访13～46个月,平均24个月.椎体高度术后恢复至正常高度的97.8％.椎体后凸畸形角度矫正至术后3.5°.椎管容积矫正至术后椎管压迫完全解除.所有患者神经症状均有不同程度恢复.结论 经后路进行脊柱三柱重建技术,能有效矫正胸腰椎爆裂骨折的后凸畸形、解除椎管内压迫,达到术后即刻稳定,具有骨折复位满意,手术创伤较小及并发症少等特点.     

前路跳跃式减压在4节段脊髓型颈椎病临床疗效分析

目的评价前路跳跃式减压植骨融合术治疗4节段脊髓型颈椎病的临床疗效。方法对16例4节段脊髓型颈椎病患者采用跳跃式减压,保留颈5椎体,切除颈4、6椎体的分节段减压。分析手术时间、术中出血量、术后6个月植骨融合率、JOA评分改善率,节段性前突角度。结果所有患者均获随访,平均18个月。手术时间130～260min,平均180min;术中失血约300～800ml,平均650ml;术后颈椎X—RAY提示均恢复颈椎生理曲度,及椎间高度;6个月植骨融合率93．75％。无植骨块脱m或钛笼下沉、钢板螺钉断裂松脱、脑脊液瘘及感染等严重并发症发生。术后3、6个月及术后1年JOA评分为（13．6±1．3）、（13．9±1．1）、（14．O±0．8）分（P〈0．05）,术后3、6个月平均改善率为56．4％、60．2％、61．5％。节段性前突角度术前（9．38＋3．0）,术后（16．22＋1．9）。（P〈0．05）。结论颈椎前路跳跃式减压植骨融合术治疗四节段脊髓型颈椎病是较好的手术方式,具有更多优点。     

自锁式椎间融合器在一期后前路联合手术治疗脊髓型颈椎病中的应用(2年随访)

[目的]分析一期颈椎后路单开门椎管成型、前路椎间减压、自锁式椎间融合器自体植骨椎间融合术治疗脊髓型颈椎病的疗效.[方法]2006年9月～ 2008年4月,采用一期颈椎后路单开门椎管成型、前路椎间减压、自锁式椎间融合器自体植骨椎间融合术连续治疗脊髓型颈椎病52例;前路椎间减压单节段23例、双节段29例.记录患者术前及术后的JOA评分,在颈椎侧位X线片上测量椎间隙高度、椎间前凸角、颈椎前凸角的变化.[结果] 52例共随访24～40个月(平均30个月).52例患者在术后2周内均感到神经症状明显好转;没有发生手术相关并发症.术后6个月随访时,所有患者主诉四肢感觉、肌力、活动均较前明显改善,颈椎X线检查可见椎间已融合,椎间高度及生理曲度完好,无融合器移位、下沉、断裂发生.平均JOA评分由术前(7.3±0.5)分,提高到术后6个月(14.1±0.7)分,术后12个月(14.7±0.6)分,术后24个月(14.9±1.2)分;术后6个月随访时的JOA评分改善率:优21例,良25例,可6例,术后12个月及术后24个月时的JOA评分改善率与术后6个月无明显改变.[结论]采用一期颈椎后路单开门椎管成型、前路椎间减压、自锁式椎间融合器自体植骨椎间融合术治疗脊髓型颈椎病能获得颈髓前后方的充分减压及满意的临床疗效,能获得满意的颈椎曲度、稳定性重建及椎间融合.     

Anterior cervical pedicle screw and plate fixation using fluoroscope-assisted pedicle axis view imaging: a preliminary report of a new cervical reconstruction technique

Anterior procedures in the cervical spine are feasible in cases having anterior aetiologies such as anterior neural compression and/or severe kyphosis. Halo vests or anterior plates are used concurrently for cases with long segmental fixation. Halo vests are bothersome and anterior plate fixation is not adequately durable. We developed a new anterior pedicle screw (APS) and plate fixation procedure that can be used with fluoroscope-assisted pedicle axis view imaging. Six patients (3 men and 3 women; mean age, 54 years) with anterior multisegmental aetiology were included in this study. Their original diagnoses comprised cervical myelopathy and/or radiculopathy (n = 4), posterior longitudinal ligament ossification (n = 1) and post-traumatic kyphosis (n = 1). All patients underwent anterior decompression and strut grafting with APS and plate fixation. Mean operative time was 192 min and average blood loss was 73 ml. Patients were permitted to ambulate the next day with a cervical collar. Local sagittal alignment was characterised by 3.5° of kyphosis preoperatively, which improved to 6.8° of lordosis postoperatively and 5.2° of lordosis at final follow-up. Postoperative improvement and early bony union were observed in all cases. There was no serious complication except for two cases of dysphagia. Postoperative imaging demonstrated screw exposure in one screw, but no pedicle perforation. APS and plate fixation is useful in selected cases of multisegmental anterior reconstruction of cervical spine. However, the adequate familiarity and experience with both cervical pedicle screw fixation and the imaging technique used for visualising the pedicle during surgery are crucial for this procedure.     

纳米羟基磷灰石/聚酰胺66复合人工椎体在颈椎病前路椎体次全切除术中的临床应用

目的 探讨纳米羟基磷灰石/聚酰胺66(n-HA/PA66)复合人工椎体在颈椎前路次全切除术中应用的短中期临床疗效.方法 自2008年5月～2009年6月对44例脊髓型颈椎病行前路椎体次全切除、椎管减压、n-HA/PA66复合人工椎体植骨融合+钢板内固定术治疗,以JOA评分改善率评价神经功能恢复情况,并依据X线片判断椎间稳定性和融合情况.结果 本组无术中并发症,伤口均一期愈合.患者获随访12～26个月,平均18个月,症状均明显改善,JOA评分由术前(6.4±1.8)分提高到术后(15.2±1.5)分,JOA改善率83.0％,优良率86.4％,问卷调查满意度97.6％.X线检查证实无人工椎体移位、下沉,融合率100％.结论 n-HA/PA66复合人工椎体具有良好的生物相容性及安全性,是一种较理想的骨移植材料,适用于颈椎病前路次全切除术中.     

椎弓根螺钉联合椎间植骨融合器治疗腰椎滑脱症的远期疗效分析

[目的]探讨椎弓根螺钉系统联合椎间植骨融合器治疗峡部不连性腰椎滑脱症的远期疗效。[方法]自1996年10月~2002年10月本组收治峡部不连性腰椎滑脱症105例,随访资料齐全者86例。所有患者均行椎弓根螺钉系统复位滑脱,椎间植骨融合器行椎间融合固定。62例患者中1枚融合器从后斜向前呈45°植入,24例为2枚融合器从后向前垂直植入。随访测定固定节段的椎体间有无移位、滑脱有无复发,比较术前、术后2周及随访时固定椎间隙高度与近端第2椎间隙高度比值的变化。[结果]随访2~8年,平均35个月。根据NaKai评分标准,本组优56例,良13例,可17例,优良率为80.23%。Ⅰ度腰椎滑脱19例术后全部解剖复位;Ⅱ度腰椎滑脱51例中5例遗留Ⅰ度滑脱;Ⅲ度腰椎滑脱16例中4例留有Ⅰ度滑脱。末次随访时使用1枚融合器或2枚融合器所固定的椎间隙高度与近端第2椎间隙高度的比值与术后2周时的比值相比有所减低,滑脱无复发。[结论]椎弓根螺钉加椎间植骨融合器治疗腰椎滑脱症手术疗效满意,显著提高融合率,预防神经根管狭窄、神经卡压的发生,减少术后断钉和滑脱复发等问题。     

Single stage anterior cervical reconstruction with titanium mesh cages, local bone graft, and anterior plating.

BACKGROUND CONTEXT: After cervical corpectomy, the use of tricortical autologous bone to fill the large defect is biomechanically and structurally inadequate and may lead to excessive donor site pain and morbidity. The major alternative, fibular strut allograft, has inherent problems that lead to lower rates of solid arthrodesis and graft migration. Majd et al. reported on 34 cases with a 97% solid fusion rate using titanium mesh cages and local bone graft to fill the cervical corpectomy defect. PURPOSE: With long-term results, to confirm the results previously reported by Majd et al. STUDY DESIGN/SETTING: Retrospective chart and radiological review. PATIENT SAMPLE: The first 26 patients in the senior author's practice eligible for a minimum 2-year follow-up, having had cervical corpectomy reconstructed with titanium mesh cages, local bone graft and anterior plating. OUTCOME MEASURES: Odom's criteria were used to assess clinical outcome. Anteroposterior, lateral and lateral flexion and extension radiographs were used to assess fusion. METHODS: Twenty-six patients with multilevel cervical pathology underwent successful corpectomy, decompression and fusion with titanium mesh cages filled with local bone graft. Rigid anterior plating was applied across the corpectomy defect. Preoperative, operative and postoperative chart data were collected retrospectively. Radiographic assessment included a minimum 2-year follow-up. RESULTS: Follow-up ranged from 24 to 64 months. Clinically, 21 of 26 (80.7%) had an excellent or good clinical outcome. No radiolucencies or motion were detected on radiographic analysis, yielding a fusion rate of 100% (26 of 26). Broken or pulled out screws were identified in two patients, one of whom had plate revision. All cages remained intact with no evidence of cage settling or collapse. CONCLUSIONS: The use of titanium mesh cages in conjunction with local bone graft, and rigid anterior plating is effective for cervical reconstruction after corpectomy and a viable alternative to the use of fibular strut allograft. These results confirm those previously reported by Majd et al.     

下腰椎失稳合并椎管狭窄症的手术治疗

目的：观察下腰椎失稳合并椎管狭窄症患者经椎弓根螺钉系统及椎体融合器治疗的效果。方法：采用后路减压，椎弓根螺钉系统内固定，椎体间融合器BAK融合。结果：术后随访1年一4年3个月(平均2年4个月)，椎体间骨性融合率1年89．6％，2年2个月100％，临床症状消失满意率92％。结论：采用椎管减压、椎弓根螺钉系统加椎间融合器固定，可使滑脱失稳的椎体部分或全部复位，保证脊柱骨性融合，达到脊柱稳定、解除症状的目的。     

颈胸结合部重建手术的临床分析

 目的探讨颈胸结合部疾患手术入路和手术方式的选择及其重建的稳定性。方法 2001 年 1月至 2009年 2月, 手术治疗颈胸结合部(C₇~T₂)疾患 86例。患者平均年龄 43.1岁(17~70岁)。行前 路手术 57例(植骨融合 38例, 椎间融合器融合 5例, 钛网植入 14例), 后路手术 21例(椎弓根螺钉固 定 9例, 侧块螺钉+椎弓根螺钉固定 12例), 前后联合入路 8例。对 53例颈胸结合部脊柱脊髓损伤者采 用美国脊髓损伤协会(American Spinal Injury Association, ASIA)评分, 对其余 33例颈胸结合部病变者采 用日本矫形外科学会(Japanese Orthopaedic Association, JOA)评分评价神经功能恢复情况。 BohlmanX 线标准判定植骨融合及脊柱生理曲度、椎间隙高度的恢复情况。结果 69例患者获 3~45个月随访, 平 均 12.4个月。ASIA评分术前平均 1.8, 术后 2.3分;JOA评分术前平均 10.3分, 术后 12.8分, 术后改善率 为 38.0%。按 Bohlman标准, 植骨均融合, 62例颈胸段椎间隙高度及生理曲度恢复。术后 1例出现呼吸 功能障碍, 1例脑脊液漏, 2例声音嘶哑, 1例复查时出现螺钉松动。结论 颈胸结合部疾患重建手术如 适应证、入路及重建方式选择正确, 能够恢复椎间隙高度、生理曲度及颈椎序列。手术入路及重建方法 的选择应根据病变部位、种类、致压因素、损伤类型及程度、脊柱稳定性及术者经验等因素综合考虑。     

Achievement of normal sagittal plane alignment using a wedged carbon fiber reinforced polymer fusion cage in treatment of spondylolisthesis.

BACKGROUND CONTEXT: Previous clinical studies of interbody fusion cages have generally failed to report sagittal plane alignment. In some cases, parallel-sided cages have contributed to loss of lumbar lordosis. A wedged-shaped carbon-fiber-reinforced polymer (CFRP) cage implant filled with autologous bone was designed to allow surgeons to more easily achieve normal sagittal plane alignment in posterior lumbar interbody fusion (PLIF). PURPOSE: This study was conducted to test the safety and efficacy of the wedged CFRP cage and the ability of surgeons to achieve normal anatomic alignment using an implant of this shape. STUDY DESIGN/SETTING: The wedged CFRP cage with pedicle screw fixation was evaluated in the treatment of patients with spondylolisthesis in a 2-year prospective study performed at 12 centers under a Food and Drug Administration (FDA)-approved protocol PATIENT SAMPLE: Inclusion criteria included patients with isthmic or degenerative spondylolisthesis at a single level below L4 with a translational malalignment of 3 mm or greater. Exclusion criteria included patients with more than 90% translation, previous surgery or abnormalities at more than two levels. OUTCOME MEASURES: Traditional outcome measures have included clinical success (improvement in pain and function) and fusion success (proof of living bone bridging the fusion area). This study adds a more complete analysis of anatomic success (restoration or maintenance of normal disc space height and sagittal plane alignment). METHODS: A clinical study of PLIF with pedicle screw fixation included a prospective group of 46 patients treated for spondylolisthesis. This article presents the data from the FDA-approval protocol. RESULTS: Fusion success was achieved in 35 of 36 patients (97.2%) reaching the 2-year follow-up interval. Clinical success was achieved in 35 of 37 (94.6%), and overall success was achieved in 33 of 36 (91.2%). Disc space height averaged 8.3 mm preoperatively, was increased to 10.2 mm at surgery and was maintained at 9.8 mm at 2 years. L4-S1 sagittal plane alignment was maintained within normal range, averaging 30.6 degrees after surgery. Clinical and fusion success rates trended higher than previous results with the rectangular cage but were not statistically different. Fusion success was significantly better than prior literature for treatment of spondylolisthesis (p=.0160). Complications of the surgery trended lower but were not statistically different from the study of the rectangular cage. CONCLUSIONS: The wedged CFRP cage with pedicle screw fixation allows surgeons to maintain normal sagittal plane alignment. These devices are safe and effective for treatment of spondylolisthesis and are FDA approved in the United States.     

Comparison between anterior cervical discectomy fusion and cervical corpectomy fusion using titanium cages for reconstruction: analysis of outcome and long-term follow-up

Retrospective comparative study of 80 consecutive patients treated with either anterior cervical discectomy fusion (ACDF) or anterior cervical corpectomy fusion (ACCF) for multi-level cervical spondylosis. To compare clinical outcome, fusion rates, and complications of anterior cervical reconstruction of multi-level ACDF and single-/multi-level ACCF performed using titanium mesh cages (TMCs) filled with autograft and anterior cervical plates (ACPs). Reconstruction of the cervical spine after discectomy or corpectomy with titanium cages filled with autograft has become an acceptable alternative to both allograft and autograft; however, there is no data comparing the outcome of multi-level ACDF and single-/multi-level ACCF using this reconstruction. We evaluated 80 consecutive patients who underwent surgery for the treatment of multi-level cervical spondylosis at our institution from 1998 to 2001. In this series, 42 patients underwent multi-level ACDF (Group 1) and 38 patients underwent ACCF (Group 2). Interbody TMCs and local autograft bone with ACPs were used in both procedures. Medical records were reviewed to assess outcome. Clinical outcome was measured by Odom’s criteria. Operative time and blood loss were noted. Radiographs were obtained at 6 and 12 weeks, 6 months, 1 year, and 2 years (if necessary). Early hardware failures and pseudarthroses were noted. Cervical sagittal curvature was measured by Ishihara’s index at 1 year. Group 1 had a mean age 46.2 years (range 35–60 years). Group 2 had a mean age 50.1 years (range 35–70 years).The operative time was significantly lower (P < 0.001) and blood loss significantly higher (P < 0.001) in Group 2 than in Group 1. At a minimum of 1 year follow up, patients in both groups had equivalent improvement in their clinical symptoms. The fusion rates for Group 1 were 97.6 and 92.1% for Group 2. The rates of early hardware failure were higher in Group 2 (2.6%) than in Group 1 (0%). The fusion rates for Group 1 were not significantly higher than Group 2 (P > 0.28). There was one patient in Group 1 and 2 patients in Group 2 with pseudarthroses. Complication rates in Group 2 were not significantly higher (P > 0.341). Cervical lordosis was well-maintained (80%) in both groups. Both multi-level ACDF and ACCF with anterior cervical reconstruction using TMC filled with autograft and ACP for treatment of multi-level cervical spondylosis have high fusion rates and good clinical outcome. However, there is a higher rate of early hardware failure and pseudarthroses after ACCF than ACDF. Hence, in the absence of specific pathology requiring removal of vertebral body, multi-level ACDF using interbody cages and autologous bone graft could result in lower morbidity.