Polyetheretherketone (PEEK) cage filled with cancellous allograft in anterior cervical discectomy and fusion

From July 2004 to June 2005, 19 patients with 25 discs underwent anterior cervical discectomy and interbody fusion (ACDF) in which polyetheretherketone (PEEK) cages were filled with freeze-dried cancellous allograft bone. This kind of bone graft was made from femoral condyle that was harvested during total knee arthroplasty. Patient age at surgery was 52.9 (28-68) years. All patients were followed up at least 1 year. We measured the height of the disc and segmental sagittal angulation by pre-operative and post-operative radiographs. CT scan of the cervical spine at 1 year was used to evaluate fusion rates. Odom's criteria were used to assess the clinical outcome. All interbody disc spaces achieved successful union at 1-year follow-up. The use of a PEEK cage was found to increase the height of the disc immediately after surgery (5.0 mm pre-operatively, 7.3 mm immediately post-operatively). The final disc height was 6.2 mm, and the collapse of the disc height was 1.1 mm. The segmental lordosis also increased after surgery (2.0 degrees pre-operatively, 6.6 degrees immediately post-operatively), but the mean loss of lordosis correction was 3.3 degrees at final follow-up. Seventy-four percent of patients (14/19) exhibited excellent/good clinical outcomes. Analysis of the results indicated the cancellous allograft bone-filled PEEK cage used in ACDF is a good choice for patients with cervical disc disease, and avoids the complications of harvesting iliac autograft.     

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.     

Healing properties of allograft from alendronate-treated animal in lumbar spine interbody cage fusion

This study investigated the healing potential of allograft from bisphosphonate-treated animals in anterior lumbar spine interbody fusion. Three levels of anterior lumbar interbody fusion with Brantigan cages were performed in two groups of five landrace pigs. Empty Brantigan cages or cages filled with either autograft or allograft were located randomly at different levels. The allograft materials for the treatment group were taken from the pigs that had been fed with alendronate, 10 mg daily for 3 months. The histological fusion rate was 2/5 in alendronate-treated allograft and 3/5 in non-treated allograft. The mean bone volume was 39% and 37.2% in alendronate-treated or non-treated allograft (NS), respectively. No statistical difference was found between the same grafted cage comparing two groups. The histological fusion rate was 7/10 in all autograft cage levels and 5/10 in combined allograft cage levels. No fusion was found at all in empty cage levels. With the numbers available, no statistically significant difference was found in histological fusion between autograft and allograft applications. There was a significant difference of mean bone volume between autograft (49.2%) and empty cage (27.5%) (P<0.01). In conclusion, this study did not demonstrate different healing properties of alendronate-treated and non-treated allograft for anterior lumbar interbody fusion in pigs.     

A meta-analysis of autograft versus allograft in anterior cervical fusion

We performed a meta-analysis of one- and two-level anterior cervical interbody fusion (ACDF) on data derived from published, peer-reviewed journal articles to determine whether there is a difference in fusion rate, graft complications, or clinical outcome in patients undergoing ACDF according to whether autograft or allograft was used. ACDF is a common procedure for cervical spondylotic radiculopathy. Most published studies comparing autograft and allograft have not demonstrated any difference between grafts. The medical literature dating from 1955 was reviewed. Of 395 titles, only four studies comparing autograft with allograft in ACDF were appropriate for this analysis. The data from these studies – 310 patients and 379 intervertebral levels – were pooled and statistical methods were applied. For both one- and two-level ACDF, autograft demonstrated a higher rate of radiographic union and a lower incidence of graft collapse. It was not possible to ascertain whether autograft is clinically superior to allograft. Although autograft has a higher fusion rate than allograft, clinical results do not depend solely on radiographic results. The risk of graft site morbidity and patient preference should be considered when choosing the type of graft for this operation. Received: 29 November 1999/Revised: 29 February 2000/Accepted: 23 March 2000     

Use of the anterior interbody fresh-frozen femoral head allograft in circumferential lumbar fusions

Many studies in the literature have documented the outcome of circumferential lumbar fusions. However, no study has specifically evaluated the performance of the anterior fresh-frozen femoral head allograft as a structural interbody graft material. All office and hospital records, including charts and radiographs, were reviewed to obtain pertinent clinical and radiographic information. The cases included 23 single-level fusions, 22 two-level fusions, and 5 fusions of three or more levels. In all, 88 fusion levels were analyzed radiographically. The mean follow-up time was 28 months (range, 24 to 36 months). All procedures were performed in a single stage. At the latest follow-up, clinical outcome was graded good to excellent in 39 (78%) cases, fair in 8 (16%) cases, and poor in 3 (6%) cases. The average time to anterior radiographic fusion was 6 months (range, 4 to 8 months). The overall fusion rate was 98%. The average preoperative anterior disk space height was 10 mm, 14 mm immediately after operation, and 13 mm at follow-up. The posterior disk space height averaged 5 mm before operation, 7 mm immediately after operation, and 6 mm at follow-up. The average segmental lordosis was 7 degrees before operation, 10 degrees immediately after operation, and 10 degrees at follow-up. Late postoperative disk space collapse of 3 mm or more was noted in 17% of the fused disk spaces examined. Seventy-eight percent of the disk spaces maintained a disk space height greater than that of their preoperative value at the latest follow-up. Segmental lordosis did not change significantly at follow-up. The occurrence of collapse did not correlate with the clinical result, smoking history, or surgical indication (p < 0.05). Perioperative complications included one pleural effusion, two urinary tract infections, and one deep wound infection. Late complications included five painful graft sites and two patients with pseudarthrosis. Fresh-frozen femoral head allograft fulfills its desired function as an anterior structural graft in combination with rigid posterior transpedicular fixation, maintaining the disk space height achieved at surgery while reliably allowing remodeling and incorporation into a solid anterior fusion.     

聚合物颈椎椎间融合器研究进展

聚合物颈椎椎间融合器具有维持颈椎生理曲度和椎间隙高度、提供初始力学稳定性、促进椎体间融合的特点,在颈椎前路减压融合术中应用广泛。该文对常用聚合物颈椎椎间融合器（包括不可降解的聚醚醚酮、聚酰胺、聚乙烯、聚丙烯酸酯椎间融合器以及可降解的聚乳酸、氨基酸共聚物椎间融合器）的研究进展进行综述。     

The use of allograft (and avoidance of autograft) in anterior lumbar interbody fusion: a critical analysis

The aim of this report is to analyze the validity of allograft in anterior lumbar interbody fusion. Forty-three patients underwent anterior lumbar interbody fusion using allograft in the period between 1995 and 1998. All suffered from crippling chronic low back pain with or without sciatica. Discogenic disease was verified in 40 cases by discography. All patients were investigated preoperatively with magnetic resonance imaging (MRI). The surgical technique is described. Follow-up radiographs were performed postoperatively, then at 1.5, 3, 6 and 12 months, as required. Radiological fusion was confirmed in all single-level fusions (100%, n=24). In two-level fusions the rate was 93% (n=28/30). However, radiological union could only be confirmed in 11 of the 12 levels in the three-level fusions. Allograft offers a better alternative to autograft for anterior lumbar interbody fusion. Donor site morbidity is avoided, hospital stay is shorter and fusion rates are satisfactory.     

The use of freeze-dried allograft bone for anterior cervical fusions

A consecutive series of 87 patients undergoing Smith-Robinson anterior cervical fusion were analyzed. Either freeze-dried tricortical iliac crest bone or tricortical autograft bone was used. Surgical technique was otherwise identical. Radiography showed delayed union at 3 months in 13% of patients with autograft and in 37% of patients with freeze-dried allograft. At 1 year, radiography showed nonunion in 8% of patients with autograft and in 22% of patients with allograft. One-level procedures had a delayed union rate of 7% for autograft and 21% for allograft. Nonunion in one-level procedures was 5% for both autograft and allograft. For two-level procedures, the nonunion rate was 17% for autograft and 63% for allograft. Graft collapse was more commonly seen with freeze-dried allograft (30%) than with autograft (5%). Relief of neck and arm pain, however, was similar in both groups.     

颈椎椎体间异体骨螺纹融合支架的设计和临床应用

目的 探讨以异体骨螺纹融合支架(allograftthreaded fusion cage,ATFC) 做颈椎椎体间融合的临床效果。方法 自1996 年4 月用自行研制的ATFC 治疗颈椎间盘疾病18 例,21 个椎节。术后观察临床效果及手术并发症,并做X 线征评价。结果 手术18 例,获随访15 例,平均随访15 个月。临床疗效满意,无神经并发症发生。ATFC 无移位及骨折。术后3 个月动态摄X 线片,除1 个椎节未融合外,其他均获骨性融合。手术椎间隙无高度丢失或成角畸形。结论 作者认为同传统颈椎前路减压椎间融合术相比,该手术优点在于:(1) 术中无需再取自体髂骨植骨,手术创伤小,时间短;(2) 椎间融合率高,可以达到近似自体髂骨植骨的融合率;(3) 支架置入牢靠,椎间稳定性好;(4)能有效维持椎间隙高度,减少椎间隙狭窄带来的并发症     

Anterior interbody fusion of the cervical spine with coralline hydroxyapatite.

STUDY DESIGN: A nonrandomized, retrospective human study of patients requiring anterior discectomy and reconstruction from C3 to T1. The pattern of incorporation, presence or absence of disc space collapse, maintenance of correction, and clinical outcomes were considered. OBJECTIVE: To determine the efficacy of coralline hydroxyapatite as a bone replacement in anterior interbody fusions of the cervical spine used in conjunction with rigid plate fixation. SUMMARY OF THE BACKGROUND DATA: Autograft is the gold standard for anterior interbody fusion of the cervical spine. Reported complication and morbidity rates with the use of autograft are as high as 21%. Using allograft instead of autograft presents numerous problems including lower rates of fusion. Other bone substitutes such as ceramics and polymethylmethacrylate are ineffective for fusion. METHODS: Twenty-six skeletally mature patients underwent anterior decompression, stabilization, microdiscectomy, and reconstruction with Pro Osteon 200 (Interpore Cross International, Irvine, CA) coralline hydroxyapatite and AO anterior cervical locking plates. Iliac crest autograft, local bone, and allograft were not used. RESULTS: The minimum follow-up period was 2 years (average, 30 months). There was no evidence of plate breakage, screw breakage, resorption of the implant, or pseudarthrosis. Two patterns of incorporation were identified. The implant incorporated totally in 100% of the disc spaces. Average hospital stay was 1.6 days. The average decrease in pain was 75.8%. There was no evidence of nonunion. CONCLUSIONS: The use of Pro Osteon 200 with rigid anterior plating seems promising as a bone replacement in the cervical spine. The incorporation rate is exceedingly high, and the complication rate nonexistent.     

Threaded cages for degenerative cervical disease.

Multiple techniques are used to accomplish anterior interbody fusion in the cervical spine. These various options reflect the lack of any one approach to obtain superior results. Extrapolating from the lumbar spine experience, a cervical cage was proposed as an alternative to the status quo. A device evaluation study was done to determine the safety and efficacy of the cage with a comparison with current allograft or autograft fusion techniques. The study resulted in two publications. One study is a multicenter trial whereas the other is a one-author study with long-term results. A review of the data from both studies follows. Comparable outcomes were seen with the allograft and autograft control group and the experimental group in the multicenter trial. However, that study reported significantly better fusion rates for the patients with cervical cages compared with the control group. Both studies reported a high percentage of donor site morbidity in the patients in the control group who had autograft fusion. A trend toward better outcomes for patients who received a cervical cage was seen in the long-term followup study. The data presented suggest interbody fusion cages are a safe and effective treatment of degenerative cervical disc disorders and avoid iliac crest donor site morbidity.     

脊髓型颈椎病前路减压内固定价值

目的：评价脊髓型颈椎病前路减压后应用内固定的价值。方法：对112例脊髓型颈椎病患者采用经前路减压、自体髂骨或钛质网笼植骨及AO颈椎带锁钢板内固定,获得随访104例,平均随访时间30个月,观察植骨融合率、融合节段间高度和颈椎生理曲度维持情况以及内植物并发症,并对神经功能恢复进行评价。 结果：94例单节段和两节段病变者术后3个月内获得牢固骨性融合,融合率为100％,10例三节段手术者融合率为80％,内植物并发症为2．9％（3／104）。全部病例术后椎间高度和生理曲度维持满意,JOA评分由术前平均10．3分提高到术后平均14．8分,平均改善率为67．2％。结论：脊髓型颈椎病前路手术后采用内固定可显著提高植骨融合率,并有效地维持椎间高度和颈椎生理曲度,有广泛的应用价值。     

Combined interbody cage and anterior plating in the surgical treatment of cervical disc disease

The purpose of this study was to evaluate the results of treatment of symptomatic cervical disc herniation using interbody cages and anterior plate fixation. Fifteen patients were studied retrospectively. An MRI study of the cervical spine was performed preoperatively in all patients. The levels involved were C5-C6 in 9 cases, C6-C7 in 4 and C3-C4 in 1, while 1 patient had disc disease at the C5-C6, C6-C7 levels, Surgical treatment included anterior approach of the cervical spine, removal of the degenerative disc, excision of osteophytes and insertion of an interbody cage which was filled in with bovine allograft and demineralised bone matrix. The spinal unit was stabilized with an anterior plate and screws. No cervical splint was used postoperatively. The patients were followed up for 7 years on average after surgery. No failure or migration of the implants was noted, while bone fusion was achieved radiologically within 6 months postoperatively in all cases. The benefits of this surgical technique are the maintenance of cervical lordosis and disc space height, the high fusion rate, as well as avoidance of cervical orthoses.     

异体骨椎间融合器在颈椎前路融合术中的应用价值

目的探讨螺纹异体骨椎间融合支架(allograft interbody fusion cage,AIFC)在颈椎前融合术中的应用价值.方法自1998年6月～2000年6月,采用AIFC行颈椎前路融合术90例,其中男35例,女55例,年龄37～72岁,平均47岁,其中神经根型颈椎病56例,脊髓型颈椎病32例,椎动脉型颈椎病2例.采用颈前横行切口,C臂X线透视定位病变间隙,行环钻前路减压,AIFC植入融合固定.术后随访观察AIFC的融合率,椎间高度维持情况及有无并发症.结果76例获得良好随访,随访时间18个月～3年,平均26个月,术后3 d、1、3、6、9、12、18、24个月常规X线片检查,74例获得骨性融合,融合率为97.3%,椎间高度维持良好,AIFC无移位,2例成角畸形愈合,颈椎呈后凸畸形.结论AIFC具有良好的维持椎间高度功能,抗压缩、抗旋转,稳定性好,椎间融合率高,符合颈椎生物力学及临床要求.     

椎体间融合治疗腰椎间隙狭窄症的临床疗效分析

目的 分析各种椎体间融合术治疗椎间隙狭窄症的临床疗效,及其适应证。方法 采用后路全椎板减压椎体间植骨加节段内固定、后路全椎板减压双Cage植入或加用节段内固定、后路半椎板减压单Cage植入或加用节段内固定、前路椎体问撑开植骨及前路椎体间撑开双Cage植入等术式治疗腰椎间隙狭窄症84例并对疗效、适应证进行分析总结。结果 全部病例随访10-24个月,临床疗效优良率为90．5％,植骨融合率为91．7％(其中自体骨植骨融台率为84．0％,Cage植骨融合率为93．2％),椎问隙恢复高度为11．4mm(其中自体骨恢复高度为10．6mm,Cage恢复高度为11．8mm)。结论 椎体间植骨融合治疗椎间隙狭窄症具有疗效好、植骨融合率高等优点,根据不同病因选择不同术式治疗,能减少损伤、提高疗效、缩短康复时间．     

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.     

Bilateral implantation of low-profile interbody fusion cages: subsidence, lordosis, and fusion analysis.

BACKGROUND CONTEXT: The use of interbody fusion cages as a treatment for degenerative disc disease has become widespread. Low-profile cages have been developed to allow a closer fit when implanting bilateral cages in patients with smaller vertebral bodies. Some surgeons feel the open design also allows better bone contact and visualization. This is particularly true when two low-profile cages are used adjacent to one another. Because of the open design of low-profile interbody fusion cages, there has been concern regarding such issues as subsidence, lordosis and fusion rates. PURPOSE: This retrospective review of paired bilateral reduced profile interbody fusion cages was completed to assess changes in subsidence, lordosis and fusion. As a secondary goal, patient outcomes were measured to determine overall health since surgery and the patient's satisfaction with the spine surgery, in an attempt to assess the effect of the outcome variables cited supra. STUDY DESIGN: This was a retrospective evaluation of patients who underwent anterior lumbar interbody fusion with low-profile interbody fusion cages. PATIENT SAMPLE: Seventy-one consecutive patients who underwent bilateral implantation of low-profile interbody fusion cages were evaluated. OUTCOME MEASURES: A patient self-evaluation, which included a Short Form (SF)-36 and questions regarding patient satisfaction were administered to patients who were at least 1 year postoperative. Subsidence and lordosis measurements were completed. Fusion was assessed by the operating surgeon. METHODS: Low-profile interbody fusion cages (BAK/Proximity, Centerpulse Spine-Tech, Inc., Minneapolis, MN) were implanted bilaterally in at least one level from L3-L4 to L5-S1. Most patients had degenerative disc disease with leg and back pain that was not responsive to conservative treatment and demonstrated segmental instability or collapse. A small percentage of patients had either a degenerative spondylolisthesis (7.0%) or an isthmic spondylolisthesis (4.2%). Autograft harvested from the iliac crest was used in all cases. Demographic, surgical and follow-up data were retrospectively collected from patient charts. A clinical outcome questionnaire that included an SF-36 as well as questions regarding patient satisfaction was either mailed to each patient who was at least 1 year postsurgery or given to patients to complete at their 1-year visit. Patients were routinely followed radiographically before surgery, immediately after surgery and at 3, 6, 12 and 24 months after surgery. Fusion was assessed by the operating surgeon using lateral radiographs often in conjunction with a thin-slice computed tomography (CT) scan. Criteria for a successful fusion were lack of motion, anterior bridging bone and lack of lucencies on flexion/extension X-rays and/or contiguous bone through the cage using a thin-cut sagittal CT scan. Lateral X-rays on each patient were also measured for subsidence and lordosis changes. RESULTS: A total of 71 patients (45 men, 26 women) with a mean age of 43.4 years (range, 25 to 74) were evaluated. Thirty-six percent of the patients were smokers, and 96% were worker's compensation patients. Thirty-two percent of the patients had previous lumbar surgery. A total of 100 operative levels were evaluated. There were 45 one-level, 23 two-level and three three-level cases. Forty-nine percent were level L5-S1, 43% were L4-L5 and 8% were L3-L4. The mean duration of symptoms was 31.5 months. Mean surgical time, mean blood loss and mean hospital stay were 139 minutes, 186 cc and 3.34 days, respectively. There were no intraoperative or postoperative complications attributable to the construct and no cases of cage migration or collapse. Patients who were at least 1-year postsurgery and had follow-up X-rays or had undergone a CT scan at this time point were evaluated for fusion status. Sixty-three patients were assessed for fusion. Fifty-four (86%) of these patients were determined to have a solid fusion. Mean time to fusion was 10 months. Fusion was assessed as solid only if all operative levels were fully fused. Mean subsidence of the anterior region was 1.97 mm, whereas the mean subsidence of the posterior region was 0.82 mm. Lordosis was unchanged at all surgical levels with mean lordosis in L3-L4 decreasing only slightly from 13 degrees before surgery to 12 degrees after surgery. L4-L5 and L5-S1 showed only slight increases in lordosis changing from 17 to 18 degrees at L4-L5 and from 17 to 19 degrees at L5-S1. These changes were not statistically significant. The clinical outcome questionnaires had a return rate of 68%. Of the 48 patients who completed the questionnaire, 75% responded that they were happy with the surgical results and would definitely recommend the surgery to a friend. Sixty-seven percent agreed that surgery met their expectations or that surgery improved their condition enough that they would go through it again for the same outcome. The results of the SF-36 portion of the survey revealed that the physical and mental composite scores were within normal range of the US population that has experienced back pain or sciatica. CONCLUSION: Bilateral implantation of low-profile cages in this patient population led to satisfactory outcomes. Subsidence and changes in lordosis were minimal. Fusion rates were good, especially for one-level cases. Patient satisfaction was relatively high, considering the population consisted of 96% worker's compensation cases. With proper surgical technique, bilateral low-profile cages can be used effectively to treat patients with degenerative disc disease.     

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.     

Comparison of sagittal contour and posterior disc height following interbody fusion: threaded cylindrical cages versus structural allograft versus vertical cages

OBJECTIVE: Segmental restoration of sagittal contour is recognized as critical for improved long-term success following instrumented lumbar fusions. As such, the use of wedged implants has become more popular. Few studies exist to assess the postoperative lordotic and disc height changes following these varied techniques in spinal fusion. An observational radiographic study examining lumbar sagittal contour and posterior intervertebral disc space height following posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) was conducted using vertical cages (VCs), wedged structural allograft (WSA), and threaded cylindrical cages (TCCs). METHODS: Forty-nine consecutive patients (59 spinal segments) were evaluated following single- or two-level interbody fusion with either stand-alone TCCs (n = 18 levels), WSA with posterior transpedicular compression instrumentation (n = 25 levels), or VCs with posterior transpedicular compression instrumentation (n = 16 levels). Standing lumbar radiographs were measured by two independent observers preoperatively, immediately postoperatively (within 1 week), at 6-week follow-up (range 4-8 weeks), and postoperatively (at 1-year follow-up) for segmental lordosis at each level undergoing posterior interbody arthrodesis and posterior intervertebral disc space height to assess indirect nerve root decompression. RESULTS: At the 1-year follow-up, postoperative lordosis was improved in the VC group (+5.3 degrees ; P < 0.005), whereas it decreased in the WSA group (-0.9 degrees ; P = 0.407) and TCC group (-3.5 degrees ; P < 0.005). The posterior disc space height decreased in the VC group (-0.5 mm; P = 0.109), whereas it increased for both the WSA group (+1.2 mm; P = 0.05) and the TCC group (+0.8 mm; P = 0.219). CONCLUSIONS: PLIF with stand-alone TCC and PLIF (or TLIF) with WSA and posterior transpedicular instrumentation results in an increased posterior disc height and thus improved indirect nerve root decompression. PLIF (or TLIF) with VC and posterior transpedicular instrumentation results in an overall decrease in posterior disc height. However, TCC and WSA resulted in a loss of lumbar lordosis, whereas VC resulted in an increase in lumbar lordosis.     

颈椎前路钢板在脊髓型颈椎病前路手术中的作用

目的 评价内固定在脊髓型颈椎病前路减压中的作用。方法 143例脊髓型颈椎病患者经前路减压后自体髂骨植骨，带锁钢板内固定。获得随访病例132例，随访时间平均20个月，观察术后神经功能恢复情况，植骨融合率，椎间高度及颈椎生理曲度恢复情况。结果 单节段与两节段病变者术后3月均获得骨性愈合，融合率为100％，16例3节段病变者融合体为81．3％，内固定并发症为5／132(3．8％)。术后椎间高度与生理曲度均获得满意重建。JOA记分平均改善率65．8％。结论 在脊髓型颈椎病前路减压手术中应用带锁钢板内固定可有效维持椎间高度和生理曲度，并有助于后路间接减压。