Comparison of anterior cervical fusion by titanium mesh cage versus nano-hydroxyapatite/polyamide cage following single-level corpectomy

Purpose

The titanium mesh cage (TMC) is a typical metal cage device which has been widely used in cervical reconstruction for decades. Nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel biomimetic non-metal cage device growing in popularity in many medical centres in recent years. There has been no comparison of the efficacy between these two anterior reconstructing cages. The purpose of this study was to compare the radiographic and clinical outcomes of these two different devices.

Methods

Sixty-seven eligible patients with single-level ACCF using TMC or n-HA/PA66 cage for cervical degenerative diseases, with four-year minimum follow-up, were included in this prospective non-randomised comparative study. Their radiographic (cage subsidence, fusion status, segmental sagittal alignment [SSA]) and clinical (VAS and JOA scales) data before surgery and at each follow-up was recorded completely.

Results

The fusion rate of the n-HA/PA66 group was higher than TMC at one year after surgery (94 % vs. 84 %) though their finial fusion rates were similar (97 % vs. 94 %). Finial n-HA/PA66 cage subsidence was 1.5 mm with 6 % of severe subsidence over three millimetres, which was significantly lower than the respective 2.9 mm and 22 % of TMC (P < 0.0001). Lastly, SSA, VAS and JOA in TMC group were worse than in the n-HA/PA66 group (P = 0.235, 0.034 and 0.007, respectively).

Conclusions

The n-HA/PA66 cage is associated with earlier radiographic fusion, less subsidence and better clinical results than TMC within four years after one-level ACCF. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to TMC in anterior cervical construction.     

Clinical and radiological follow-up of single-level Prestige LP cervical disc replacement

Objective

To evaluate the clinical outcomes and radiographic results of patients who underwent single-level cervical arthroplasty using the Prestige LP.

Method

Thirty-one patients with single-level cervical disc disease received the Prestige LP disc replacement from June 2008 to December 2009. The neck disability index (NDI), Japanese Orthopedic Association score (JOA) and visual analogue scale (VAS) were used to assessed clinical outcomes pre-operatively and post-operatively at 24 months. The overall cervical alignment (C2–7 Cobb angle), the functional segmental unit (FSU) curvature, the range of motion (ROM) of treated and adjacent levels were measured, and the evidence of heterotopic ossification (HO) was observed from static and dynamic radiographs.

Results

There was a statistically significant improvement in the NDI from 20.2 ± 7.5 to 6.4 ± 3.5 (P < 0.000), JOA from 12.8 ± 2.2 to 16.6 ± 0.6 (P < 0.000), the neck VAS score from 4.1 ± 2.5 to 1.4 ± 1.1 (P < 0.000), the arm VAS score from 4.6 ± 2.5 to 0.7 ± 1.1 (P < 0.000). The post-operative overall cervical alignment (9.3° ± 7.2°), ROM of treated level (7.6°) and adjacent level (upper level 9.4° ± 3.1°, lower level 9.1° ± 3.5°) are well maintained. The FSU were 0.2° ± 5.4° and 1.9° ± 5.5° at pre-operation and final follow-up with statistical significance (P = 0.011). Heterotopic ossification was evidenced in five operated segment (16 %).

Conclusions

The Prestige LP disc arthroplasty maintains favorable clinical outcomes, preserves the overall cervical alignment, FSU curvature, ROM of treated level and adjacent levels.     

颈前路椎体切除植骨融合术后钛网沉陷的临床研究

目的探讨颈前路椎体切除植骨融合术后钛网沉陷的风险因素以及钛网沉陷对临床疗效的影响。方法 2003年5月～2007年8月采用颈前路椎体切除植骨融合术治疗颈椎疾病患者300例。分析患者的年龄、性别、切除节段、固定钢板的类型以及是否使用垫片这5个因素是否为钛网沉陷的风险因素,研究钛网沉陷对颈椎曲度及其他临床疗效的影响。结果随访1年,239例（79.7%）患者发生钛网沉陷,其中182例（60.7%）发生轻度沉陷（1～3mm）,57例（19.0%）发生严重沉陷（〉3mm）。双节段切除较单节段切除更易发生严重钛网沉陷。发生严重钛网沉陷的患者术后神经功能恢复率明显低于未发生钛网沉陷的患者。同时,钛网严重沉陷增加了患者颈肩部疼痛、神经症状复发以及内固定失败的发生率。结论钛网沉陷在颈前路椎体切除钛网植骨融合术后发生较为普遍。多节段切除是发生严重钛网沉陷的危险因素,严重钛网沉陷可导致手术疗效下降及相关并发症的发生。     

Differences between arthroplasty and anterior cervical fusion in two-level cervical degenerative disc disease

Purpose

Although arthroplasty is an accepted option for two-level disease, there is a paucity of data regarding outcomes of two-level cervical arthroplasty. The current study was designed to determine differences between two-level cervical arthroplasty and anterior fusion.

Methods

Seventy-seven consecutive patients who underwent two-level anterior cervical operations for degenerative disc disease were divided into the arthroplasty (37 patients) and fusion (40 patients) groups. Clinical outcomes were measured by Visual Analogue Scale (VAS) of neck and arm pain, Japanese Orthopedic Association (JOA) scores, and Neck Disability Index (NDI). Every patient was evaluated by radiography and computed tomography for fusion or detection of heterotopic ossification.

Results

Thirty-seven patients (with 74 levels of Bryan discs) were compared with 40 patients who had two-level anterior fusion (mean follow-up of 39.6 ± 6.7 months). There was no difference in sex, but the mean age of the arthroplasty group was significantly younger (52.1 ± 9.1 vs. 63.0 ± 10.6 years, p < 0.001). The mean estimated blood loss was similar (p = 0.135), but the mean operation time was longer in the arthroplasty group (315.5 ± 82.0 versus 224.9 ± 61.8 min, p < 0.001). At 24 months post-operation, the arthroplasty group had increased their range of motion than pre-operation (23.5° versus 20.1°, p = 0.018). There were significant improvements in neck or arm VAS, JOA scores, and NDI in both groups. However, there were no differences in clinical outcomes or adverse events between the two groups.

Conclusions

Clinical outcomes of two-level arthroplasty and anterior cervical fusion are similar 39.6 months after surgery. Cervical arthroplasty preserves mobility at the index levels without increased adverse effects.     

A prospective,randomised, controlled multicentre study comparing cervical disc replacement with anterior cervical decompression and fusion

Purpose

Total cervical artificial disc replacement (TDR) simulates normal disc structure, thus avoiding the drawbacks of anterior cervical decompression and fusion (ACDF). This prospective, randomized, controlled and multicentre study aimed to evaluate clinical and radiographic outcomes by comparing cervical disc replacement using Mobi-C disc prostheses with ACDF.

Methods

This prospective, randomized, controlled and multicentre study consisted of 111 patients undergoing single-level Mobi-C disc prosthesis replacement (TDR group, n?=?55) or ACDF (n?=?56) from February 2008 to November 2009 at 11 medical centres across China. Patients were assessed before surgery, at seven days postoperation and one, three, six, 12, 24, 36 and 48 months postoperation. Clinical and neurological outcome was determined by measuring the Japanese Orthopaedic Association (JOA) scores, visual analogue scale (VAS) and Neck Disability Index (NDI). Static and dynamic radiographs were obtained of the cervical curvature, the functional spinal unit (FSU) angle and range of motion (ROM) of the cervical spine, FSU angle and treated and adjacent segments.

Results

A total of 111 patients were included and randomly assigned to either Mobi-C disc prosthesis replacement or ACDF. JOA, VAS and NDI showed statistically significant improvements 48 months after surgery (P?p?>?0.05). ROM in the ACDF group was significantly reduced at one month and remained so throughout the follow-up. By 48-months, more ACDF patients required secondary surgery (four of 56 patients).

Conclusions

Although ACDF may increase the risk of additional surgery, clinical outcomes indicated that both Mobi-C artificial cervical disc replacement and ACDF were reliable. Radiographic data showed that ROM of the cervical spine, FSU angle and treated and adjacent segments were relatively better reconstructed and maintained in the Mobi-C group compared with those in the ACDF group.     

Comparative effectiveness of PEEK rods versus titanium alloy rods in lumbar fusion: A preliminary report

Background

Posterior lumbar instruments made of titanium and its alloys could change the physiological distribution of load at the instrumented and adjacent segments, which is a main cause of implant failure, non-fusion and adjacent segment degeneration. Posterior lumbar rods made of polyetheretherketone (PEEK) which is a semirigid alternative to titanium and its alloys have been introduced in lumbar fusion. This prospective study compared the radiological and clinical outcomes of patients undergoing lumbar fusion with PEEK rods versus titanium alloy rods.

Methods

Using transpedicular fixation and lumbar fusion, 21 patients were treated with titanium alloy rods (TI group), and 20 patients with PEEK rods (PEEK group). Radiological and clinical outcomes were evaluated, including the status of the implanted instruments, fusion rate, lumbar lordosis angle (LA), disc space height (DH), visual analog score (VAS) for lower back pain (VAS-BP) and leg pain (VAS-LP), Japanese Orthopedic Association scoring system (JOA score) and complications.

Results

Clinical VAS-BP, VAS-LP and JOA scores were significantly improved at 3 months, 6 months, and 1 year postoperatively as compared with preoperative scores in both groups (p?<?0.05), with similar levels of improvement observed at the same time points postoperatively between the two groups. The overall fusion rate was 100 % at the 1-year follow-up for both groups. No significant differences in lumbar lordosis angle were found preoperatively, 1 week and 1 year postoperatively in both groups (p?>?0.05). The postoperative increase of disc space height and loss of disc space height during the follow-up showed a similar extent of change between both groups (p?>?0.05).

Conclusions

PEEK rods offer a similar radiological and clinical efficacy as titanium alloy rods. PEEK rods, as a semirigid implant with unique characteristics, may be an effective alternative treatment for patients with degenerative lumbar disease in lumbar fusion.     

一种新型植骨重建钛网的初步临床应用

目的评价新型植骨重建钛网在颈前路椎体次全切除减压植骨融合术中的临床应用及疗效。方法采用颈前路椎体次全切除减压、新型钛网植骨融合术治疗颈椎退行性疾病患者53例,其中男38例,女15例,年龄39～76岁,平均49.7岁。手术方式包括单节段椎体次全切除22例,单节段椎体次全切除联合椎间盘切除减压28例,双节段椎体次全切除3例。术后定期随访颈椎X线片,比较术后椎间高度及颈椎生理曲度变化。采用日本骨科学会的JOA评分系统进行神经功能评价。结果单节段手术患者椎间高度从术前22.3mm±0.8mm增加至术后24.5mm±0.6mm,双节段手术患者椎间高度从术前平均42.3mm增加至术后平均45.7mm,6个月随访两者均无明显丢失。单节段手术患者颈椎曲度从术前8.2°±1.4°增加至术后14.5°±1.6°,但双节段手术患者颈椎曲度术前平均6.3°,术后平均仅为7.0°,6个月随访两者均无明显丢失。全部患者临床神经功能均有改善,JOA评分从术前8.4±0.5分提高至术后12.2±0.4分,6个月随访提高至14.5±0.3分。结论新型钛网的外形设计更符合颈椎椎体终板形态学特点,可有效避免术后钛网沉陷,临床应用单节段手术能够较好的重建颈椎椎间高度和生理曲度,而双节段手术由于该新型钛网设计的不足之处对于颈椎生理曲度的重建作用有限,有待进一步改进。     

Comparison of titanium and polyetheretherketone (PEEK) cages in the surgical treatment of multilevel cervical spondylotic myelopathy: a prospective, randomized, control study with over 7-year follow-up

Purpose

Anterior cervical discectomy and fusion (ACDF) with titanium- or polyetheretherketone (PEEK)-cage reconstruction is widely used in the treatment of cervical spondylotic myelopathy (CSM). This study was to compare outcomes of titanium and PEEK cages in the treatment of multilevel CSM.

Methods

Between November 2002 and December 2004, a total of 80 patients with 3-level CSM were randomized in a 1:1 ratio to titanium group and PEEK group. The overall follow-up period of the patients ranged from 86 to 116 months (average 99.7 months). Clinical and radiological results were compared between titanium group and PEEK group.

Results

At the final follow-up, the clinical outcomes including JOA score, NDI score, and the excellent and good rates of clinical outcomes in the PEEK group were better than those in the titanium group. More loss of the Cobb angles and the intervertebral height was observed in the titanium group, resulting in the radiological parameters in the titanium group becoming inferior to the PEEK group at the final follow-up. Cage subsidence rates were 34.5 and 5.4 % in the titanium and PEEK groups, respectively. Fusion was observed in all patients of two groups at the final follow-up. Two patients presented with cage dislocation without clinical symptoms in the titanium group.

Conclusions

In surgical treatment of multilevel CSM, PEEK cage is superior to titanium cage in maintenance of intervertebral height and cervical lordosis, resulting in better clinical outcomes in the long-term follow-up.     

Vertebral rotation in adolescent idiopathic scoliosis calculated by radiograph and back surface analysis-based methods: correlation between the Raimondi method and rasterstereography

Purpose

The aim of the present research is to evaluate the relationship between an X-ray-based method (i.e. the Raimondi method) and rasterstereography in the evaluation of vertebral rotation (VR) in a sample of adolescent idiopathic scoliosis (AIS) patients.

Methods

A total of 25 patients (9 males; mean age 14 ± 3 years; mean height 160.7 ± 11.9 cm; mean weight 52.4 ± 10.7 kg) were considered for the present analysis. The mean Cobb angle was 30° ± 9°. The evaluation of VR on radiographs was made using the Raimondi method regolo (Marrapese Editore—Demi S.r.1., Rome). Rasterstereography was performed by means of Formetric 4D^® (Diers International GmbH, Schlangenbad, Germany). Correlations between rasterstereographic and radiographic measurement of VR were calculated, both for the whole sample and for thoracic and lumbar spinal segments considered separately, as well as for subgroups of patients with a Cobb angle <30° and ≥30° using Spearman’s correlation coefficient by rank (r _s).

Results

When applied to the entire spine, measurement of VR by means of the two methods highlighted a significant correlation in the whole group (r = 0.52; p < 0.0001), as well as in the <30° Cobb (r = 0.47; p = 0.0001) and ≥30° Cobb (r = 0.42; p < 0.0001) subgroups. A significant correlation was found also when lumbar and thoracic VR were considered as separated groups (r = 0.30, p = 0.024 and r = 0.47, p = 0.002, respectively).

Conclusions

Rasterstereographic evaluation of VR shows a good correlation with the Raimondi method, thereby confirming the possibility to use this non-invasive method for deformity assessment in AIS patients.     

颈椎前路手术应用端盖钛网治疗合并骨质疏松的老年脊髓型颈椎病对照研究

目的:比较颈前路椎体次全切除应用端盖钛网与无端盖钛网植骨融合术治疗合并骨质疏松的老年脊髓型颈椎病的影像结果及临床疗效。方法:对2011年1月至2016年1月采用颈前路单个椎体次全切除钛网植骨融合术治疗的60例合并骨质疏松老年脊髓型颈椎病患者进行回顾性分析,其中男26例,女34例,年龄68~79岁,平均75.8岁。根据术中所用钛网分为端盖钛网组(A组,32例)及无端盖钛网组(B组,28例)。通过JOA评分对两组患者的神经功能进行评定;通过X线对融合节段椎间高度及前凸角度(Cobb角)进行测量;通过CT评估钛网植骨融合率。结果:60例患者均获随访,随访时间1~2年,平均1.5年。临床疗效评价结果:A组术前JOA评分为9.3±1.7,术后1周、3个月、1年JOA评分分别为14.2±1.8、15.7±1.2、15.4±1.5;B组术前JOA评分为9.1±1.8,术后1周、3个月、1年JOA评分分别为14.5±1.3、14.9±1.7、15.2±1.6。两组术后JOA评分与术前相比均明显改善(P0.05)。术后1周、3个月、1年两组JOA评分比较差异均无统计学意义(P0.05)。影像学评价结果:A组术前融合节段椎间高度为(42.1±2.4)mm,术后1周、3个月、1年分别为(45.3±3.2)mm、(44.7±2.9)mm、(44.5±3.0)mm;A组术前Cobb角为(5.3±1.2)°,术后1周、3个月、1年分别为(10.3±1.9)°、(10.1±1.7)°、(9.9±1.3)°;B组术前椎间高度为(43.4±2.3)mm,术后1周、3个月、1年分别为(45.7±2.8)mm、(44.2±2.7)mm、(41.5±2.1)mm;B组术前Cobb角为(5.4±1.0)°,术后1周、3个月、1年分别为(11.2±1.8)°、(10.8±1.6)°、(7.2±1.4)°。两组术后融合节段椎间高度、融合节段Cobb角与术前比较明显提高(P0.05)。术后1周、3个月A组椎间高度、融合节段Cobb角与B组比较差异无统计学意义(P0.05),术后1年椎间高度、融合节段Cobb角A组均明显优于B组(P0.05),末次随访,A组钛网沉陷率为6%,B组为18%。结论:颈前路手术应用端盖钛网治疗合并骨质疏松的老年脊髓型颈椎病患者,术后维持椎间隙高度及融合节段前凸角度方面优于无端盖钛网,端盖钛网的应用可有效降低骨质疏松患者的钛网沉陷的发生率。     

Outcomes of posterior facet versus pedicle screw fixation of circumferential fusion: a cohort study

Purpose

To compare single-level circumferential spinal fusion using pedicle (n = 27) versus low-profile minimally invasive facet screw (n = 35) posterior instrumentation.

Method

A prospective two-arm cohort study with 5-year outcomes as follow-up was conducted. Assessment included back and leg pain, pain drawing, Oswestry disability index (ODI), pain medication usage, self-assessment of procedure success, and >1-year postoperative lumbar magnetic resonance imaging.

Results

Significantly less operative time, estimated blood loss and costs were incurred for the facet group. Clinical improvement was significant for both groups (p < 0.01 for all outcomes scales). Outcomes were significantly better for back pain and ODI for the facet relative to the pedicle group at follow-up periods >1 year (p < 0.05). Postoperative magnetic resonance imaging found that 20 % had progressive adjacent disc degeneration, and posterior muscle changes tended to be greater for the pedicle screw group.

Conclusion

One-level circumferential spinal fusion using facet screws proved superior to pedicle screw instrumentation.     

Measurement of volume-occupying rate of cervical spinal canal and its role in cervical spondylotic myelopathy

Purpose

To compare volume-occupying rate of cervical spinal canal between patients with cervical spondylotic myelopathy (CSM) and normal subjects, and to investigate its significance in cervical spine disease.

Methods

Spiral computed tomography (CT) scan (C4–C6 cervical spine unit) was performed in 20 normal subjects and 36 cases of CSM at a neutral position, and data were transferred to the Advantage Workstation Version 4.2 for assessment. Bony canal area and fibrous canal area in each cross section, and sagittal diameters of cervical spinal canal and cervical spinal body were measured. Volume-occupying rate of cervical spinal canal was calculated using MATLAB. Cervical spinal canal ratio and effective cervical spinal canal ratio were calculated, and Japanese Orthopaedic Association score was used to assess cervical spinal cord function.

Results

Volume-occupying rate of cervical spinal canal at a neutral position was significantly higher in CSM patients as compared to normal subjects (P < 0.01). There was no correlation between cervical spinal canal ratio and JOA score in CSM patients, with a Pearson’s correlation coefficient of 0.171 (P > 0.05). However, sagittal diameter of secondary cervical spinal canal, effective cervical spinal canal ratio and volume-occupying rate of cervical spinal canal were significantly associated to JOA score, with Pearson’s coefficient correlations of 0.439 (P < 0.05), 0.491 (P < 0.05) and ?0.613 (P < 0.01), respectively.

Conclusions

Volume-occupying rate of cervical spinal canal is an objective reflection of compression on cervical spine and spinal cord, and it is associated with cervical spinal cord function. These suggest that it may play a significant role in predicting the development of CSM.     

Can surgery for adolescent idiopathic scoliosis of less than 50 degrees of main thoracic curve achieve good results?

Background

It is generally recognized that the main thoracic curve Cobb angle threshold for surgical correction is approximately 50 degrees in patients with adolescent idiopathic scoliosis (AIS). Although AIS with a Cobb angle of <50 degrees is sometimes treated surgically to improve cosmesis, the precise outcomes are unclear. This study analyzed the postoperative results for AIS with a main thoracic curve of 50 degrees.

Treatment of cervical disc herniation through percutaneous minimally invasive techniques

Purpose

The goal of this study is to compare the therapeutic effectiveness of percutaneous cervical discectomy, percutaneous cervical disc nucleoplasty, and a combination of the two for the treatment of cervical disc herniation and the effective stabilization of the cervical vertebral column.

Methods

A retrospective study was performed from February 2003 to April 2011. One hundred and seventy-one cervical disc herniation patients with a mean age of 47.8 years (ranging from 21 to 74 years) participated in the study and were treated with the three types of percutaneous minimally invasive techniques: percutaneous cervical discectomy (PCD, 97 cases), percutaneous cervical disc nucleoplasty (PCN, 50 cases), and a combination of the two (PCDN, 24 cases). After treatment, the postoperative clinical results and the stability of the cervical vertebral columns of these three groups were evaluated and compared.

Results

Patients in the PCD group received follow-up care for approximately 4.1 years (ranging from 0.2 to 8.5 years), while those in the PCN group received only an average of 2.6 years (ranging from 0.3 to 7.8 years), and the PCDN group received an average of 3.3 years (ranging from 0.2 to 8 years of follow-up). According to the Japanese Orthopedic Association scoring system, the functional scores (JOA scores) differed significantly between the pre- and postoperative patients within the three groups (PCD t = 21.849, P = <0.05; PCN t = 14.503, P < 0.05; PCDN t = 8.555, P < 0.05). All patients had been successfully operated on by the same spinal surgeon team. According to the Odom criterion, the clinical outcomes were not significantly different for any of the three groups (the recovery rate using the JOA standard evaluation, F = 2.19, P = 0.116, P > 0.05). The percentages of each procedure that received either an excellent or a good rating were PCD at 81.35 %, PCN at 82.44 % and PCDN at 83.19 %. In addition, the clinical success rates among the three were not significantly different (P > 0.05). Notably, there was no postoperative instability of the cervical vertebral column in any of the patients (P > 0.05), and there was no difference in the pre- or postoperative stability of the cervical vertebral columns in each group.

Conclusions

Each group achieved good clinical outcomes with this safe, minimally invasive spinal surgery for the treatment of cervical disc herniation. In addition, no postoperative risk of cervical instability was found.     

Fusion and subsidence rate of stand alone anterior lumbar interbody fusion using PEEK cage with recombinant human bone morphogenetic protein-2

Introduction

Anterior lumbar interbody fusion (ALIF) is an established treatment for structural instability associated with symptomatic disk degeneration (SDD). Stand-alone ALIF offers many advantages, however, it may increase the risk of non-union. Recombinant human bone morphogenetic protein-2 (BMP-2) may enhance fusion rate but is associated with postoperative complication. The optimal dose of BMP-2 remains unclear. This study assessed the fusion and subsidence rates of stand-alone ALIF using the SynFix-LR interbody cage with 6 ml/level of BMP-2.

Methods

Thirty-two ALIF procedures were performed by a single surgeon in 25 patients. Twenty-five procedures were performed for SDD without spondylolisthesis (SDD group) and seven procedures were performed for SDD with grade-I olisthesis (SDD-olisthesis group). Patients were followed-up for a mean of 17 ± 6 months.

Results

Solid fusion was achieved in 29 cases (90.6 %) within 6 months postoperatively. Five cases of implant subsidence were observed (16 %). Four of these occurred in the SDD-olisthesis group and one occurred in the SDD group (57 % vs. 4 % respectively; p = 0.004). Three cases of subsidence failed to fuse and required revision. The body mass index of patients with olisthesis who developed subsidence was higher than those who did not develop subsidence (29 ± 2.6 vs. 22 ± 6.5 respectively; p = 0.04). No BMP-2 related complications occurred.

Conclusion

The overall fusion rate of stand-alone ALIF using the SynFix-LR system with BMP-2 was 90.6 %, comparable with other published series. No BMP-2 related complication occurred at a dose of 6 mg/level. Degenerative spondylolisthesis and obesity seemed to increase the rate of implant subsidence, and thus we believe that adding posterior fusion for these cases should be considered.     

Clinical and radiological results of total disc replacement in the cervical spine with preoperative reducible kyphosis

Purpose

To investigate the clinical and radiological results of total disc replacement (TDR) in the cervical spine with preoperative reducible kyphosis, and discuss when TDR is indicated for the patients with preoperative kyphosis.

Methods

Fifty-two patients who underwent single-level cervical TDR from June 2008 to May 2010 were included in this study. TDR was indicated for patients with preoperative lordosis or reducible kyphosis, and the patients were divided into a lordotic group (preoperative global angle of ≥0°) and kyphotic group (preoperative global angle of <0°). Clinical results were evaluated using the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score and Neck Disablity Index (NDI). For radiological evaluation, the global and functional spinal unit (FSU) angles and the global and FSU range of motion were measured preoperatively and postoperatively.

Results

The mean NDI in the kyphotic group was significantly higher than that in the lordotic group preoperatively and at six months postoperatively, but the groups showed no significant differences in JOA score, VAS score and NDI at the two year follow-up. The mean global and FSU angles in the kyphotic group were significantly lower than those in the lordotic group preoperatively and at six months postoperatively, but they gradually improved postoperatively. The differences lost significance at the two year follow-up.

Conclusions

Postoperative cervical kyphosis had adverse effects on the NDI after TDR. Artificial discs, symptom relief, and neck functional exercises may contribute to correction of preoperative reducible kyphosis at different stages after cervical TDR. Preoperative reducible kyphosis should not be an independent contraindication for cervical TDR.     

3D打印解剖型钛笼与传统钛笼在ACCF术中应用的比较研究

目的评估3D打印解剖型钛笼在单节段颈椎前路椎体次全切除植骨融合(ACCF)术中应用效果及其安全性。方法回顾性分析自2014-06—2015-12行C5椎体ACCF的56例脊髓型颈椎病,27例ACCF术中应用3D打印解剖型钛笼(观察组),29例ACCF术中应用传统钛笼(对照组)。比较2组手术时间、术中出血量、JOA评分改善率。术后3 d及末次随访于颈椎正侧位X线片上观察钛笼下沉距离、骨融合及融合节段Cobb角。结果 56例均获得随访,观察组随访时间(15.34±3.61)个月,对照组随访时间(15.42±2.98)个月。所有患者均达到骨性融合,融合率100%。观察组21例钛笼下沉,下沉0.3~0.7(0.52±0.21)mm,无严重下沉患者;对照组25例钛笼下沉,下沉2.3~4.2(2.93±0.42)mm,3例严重下沉;观察组钛笼下沉距离小于对照组,差异有统计学意义(P0.05)。观察组末次随访时JOA评分改善率为69.5%,对照组为67.0%,2组差异无统计学意义(P0.05)。观察组融合节段Cobb角小于对照组,差异有统计学意义(P0.05)。结论 3D打印解剖型钛笼在ACCF治疗单节段脊髓型颈椎病术中应用能够获得与传统钛笼相似的临床效果及骨性融合率,并且可以有效减少钛笼下沉现象,使用安全。     

Long-term outcome of the Cloward procedure for single-level cervical degenerative spondylosis. Clinical and radiological assessment after a 22-year mean follow-up

Purpose

To evaluate the long-term outcomes of the classical Cloward procedure in single-level cervical spondylosis.

Methods

A retrospective study of 28 patients who were affected by cervical degenerative spondylosis at C4-C7 segments and treated by the Cloward technique at a single level from 1985–1995 was conducted. The average follow-up period was 22 years (range, 17–27 years). Preoperative clinical complaints were recorded and compared to the current clinical status. Preoperative, 3–6 months postoperative and a current radiographic study were analysed by evaluating the segmental and global sagittal alignment of the cervical spine as well as the occurrence of adjacent disc degeneration.

Results

The most frequently operated segment was C5-C6 (57.1 %), followed by C6-C7 (32.1 %) and C4-C5 (7.1 %). Pain relief and symptom recovery experienced 3–6 months following the surgery was maintained at the most recent follow-up in 85 % of patients. Adjacent disc degeneration was detected in a total of 17 cases (60.7 %). Overall, a group of 14 cases (50 %) had increased lordosis at C2-C7 at the most recent follow-up, with a mean gain of 1.5º Cobb. According to Odom’s criteria, 17 patients (60.8 %) presented with excellent clinical outcome, 6 (21.4 %) presented with good outcome, 5 had a (17.8 %) fair outcome, and none had a poor outcome.

Conclusions

The Cloward technique provided excellent long-term clinical outcome in the treatment of single-level cervical degenerative spondylosis. There were no major alterations of the cervical sagittal balance, and the development of adjacent segment disease (ASD) was not specifically associated with the previous surgery.     

Reciprocal changes in cervical spine alignment after corrective thoracolumbar deformity surgery

Purpose

To identify changes in cervical alignment parameters following surgical correction of thoracolumbar deformity and then assess the preoperative parameters which induce changes in cervical alignment following corrective thoracolumbar deformity surgery.

Methods

A retrospective study of 49 patients treated for thoracolumbar deformity with preoperative planning of an acceptably aligned coronal and sagittal plane in each case. We compared cervical spine parameters in two distinct low [preoperative C7 sagittal vertical axis (SVA) ≤6 cm] and high (preoperative C7 SVA ≥9 cm) C7 SVA groups. Multilinear regression analysis was performed and revealed the relationship between postoperative cervical lordosis and preoperative spinopelvic parameters and surgical plans.

Results

In the lower C7 SVA group, cervical lordosis was significantly increased after thoracic/lumbar deformity correction (p < 0.01). In contrast, the high C7 SVA group showed decreased cervical lordosis postoperatively (p < 0.01). Multilinear regression analysis demonstrated the preoperative parameters (preoperative C2–7 angle, T1 slope, surgical plan for PT and C7 SVA), which determine the postoperative cervical lordosis.

Conclusion

In spinal deformity procedures, preoperative spinal alignment parameters, and surgical plans could affect postoperative cervical spine alignment.     

Anterior corpectomy and fusion to C2 for cervical myelopathy: clinical results and complications

Purpose

Anterior cervical corpectomy and fusion (ACCF) to C2 (ACCF-C2) for multilevel lesions is a challenging procedure that is indicated for massive ossification of the posterior longitudinal ligament (OPLL) extending to C2 or stenosis at the upper cervical region accompanied by kyphosis. However, there is little information on the effectiveness of and complications related to ACCF-C2. The purpose of this study was to investigate the overall surgical results and postoperative complications of ACCF-C2 for cervical myelopathy.

Methods

Sixteen patients who underwent ACCF-C2 for OPLL and cervical spondylotic myelopathy were evaluated. An iliac bone or a fibular strut was grafted using a cervical plate. The mean fusion level was 3.8, and the mean follow-up period was 36 months. Patients’ charts, clinical results assessed using the Japanese Orthopedic Association (JOA) scale, and radiographs were retrospectively reviewed.

Results

The average preoperative JOA score was 11.5 ± 3.5, and improved significantly to 13.1 ± 3.2 at 24 months after surgery (P < 0.01). The postoperative cervical alignment was significantly improved at the last follow-up (P < 0.05). Seven patients experienced complications, including neurological complications in three, graft-related complications in three, cerebrospinal fluid leakage in two, late retropharyngeal perforation in one, and dysphasia in one. Three of 16 patients experienced upper airway obstruction in this series, and 2 of 473 patients who underwent anterior cervical decompression and fusion at lower levels in the same period (P < 0.001).

Conclusions

ACCF-C2 is effective for massive OPLL and stenosis accompanied by kyphosis. To avoid complications, skilled decompression and bone grafting technique are necessary, and delayed extubation for upper airway obstruction is preferable.