Anterior cervical instrumentation enhances fusion rates in multilevel reconstruction in smokers

This retrospective consecutive case study evaluated the effect of anterior plating on multilevel anterior cervical decompressions and fusions in smokers and non-smokers. Multilevel anterior cervical decompression and fusion surgery in smokers provides an important challenge. Higher nonfusion rates in smokers have been reported. Cigarette smoking has been shown to interfere with bone metabolism and revascularization and to suppress bone formation. One hundred six patients underwent anterior cervical decompression and fusion using autografts or allografts and anterior plating. The minimum follow-up was 12 months. The mean age was 50.12 years (+/- 11.72; range, 27 to 80 years). Autografts were used in 90 patients and allograft in 16. The mean level fused was 2.74 (+/- 0.61). Forty-six (45.5%) patients were smokers. Successful fusion was achieved in all but three patients (97.17%). C5 root weakness was seen in four patients (3.8%); two patients experienced acute airway obstruction, of which one required tracheotomy. Temporary recurrent laryngeal nerve palsy developed in three (2.8%) patients. A fusion rate of 97% was achieved in multilevel anterior cervical decompression and fusions using anterior plating. No difference in fusion rates between smokers and nonsmokers was seen. Anterior cervical plating markedly improved the fusion rate in smokers.     

Computer navigation in dorsal instrumentation of the cervical spine--an in vitro study

Transarticular C1/2 screws are widely used in posterior cervical spine instrumentation. Pedicle screws in the cervical spine remain uncommon until now. In view of improved biomechanical stability compared to lateral mass screws, pedicle screws could be used, especially for patients with poor bone quality or defects in the anterior column. Nevertheless, there are potential risks of iatrogenic damage to the spinal cord, nerve roots, or the vertebral artery related to both techniques of posterior cervical spine instrumentation. Therefore, the aim of this study was to evaluate whether C1/2 transarticular screws as well as transpedicular screws in C3 and C4 can be applied safely and with high accuracy using a computer-assisted surgery (CAS) system. C1/2 transarticular screws as well as transpedicular screws in the cervical spine can be applied safely and with high accuracy using a CAS system in vitro. Therefore, this technique may be used in the clinical setup due to improved accuracy and reduced radiation dose for the patient and medical staff. Nevertheless, to prevent iatrogenic damage, users should be aware of known sources of possible errors that cause inaccuracies. Small pedicles with a diameter below 4.0 mm may not be suitable for pedicle screws.     

各型内固定矫形术治疗脊柱侧凸效果评价

目的评价不同内固定矫形术治疗脊柱侧凸的效果。方法对１９８４～１９９７年用不同手术方法矫治１２５例１００°以内脊柱侧凸患者的治疗和随诊资料进行研究,手术方法包括Ｈａｒｉｎｇｔｏｎ、Ｌｕｑｕｅ、联合ＨａｒｉｎｇｔｏｎＬｕｑｕｅ、ＣＤ、Ｚｉｅｌｋｅ、前路松解加后路手术和俄式手术等,对不同方法的优缺点及各自的矫正情况、身高变化、手术时间、术中输血量、住院时间、术后并发症和矫正度丢失情况及其原因进行比较分析。结果Ｈａｒｉｎｇｔｏｎ法矫正效果比其它方法差而且并发症多;Ｌｕｑｕｅ法费时且有潜在脊髓损伤之忧;ＣＤ法有三维矫正作用,矫正效果好,未见脱钩、断棍;含前路手术的方法远期Ｃｏｂｂ角度丢失少,其中前路松解加后路手术（ＣＤ术）方法简便易行,效果好;俄式手术作为一种探索中的不影响脊柱生长发育的新型脊柱侧凸内固定矫形术,有一定优越性。结论在不进行脊柱融合的新技术发展成熟前,ＣＤ术对生长发育中的青少年脊柱侧凸患者是一种较好的治疗方法     

The effect of multilevel anterior cervical fusion on neck motion

Background

Anterior cervical decompression and fusion (ACDF) procedures are successful in treating multilevel cervical radiculopathy and cervical myelopathy. It was reported that this procedure would result in a loss of cervical range of motion. However, few studies have focused on the exact impact of multilevel (more than 3 levels) ACDF on cervical range of motion.

Methods

29 patients underwent a 3-level or 4-level ACDF. In all the patients, preoperative active cervical ROM measurement was performed, and postoperative measurement was performed at 1-year follow-up by a CROM device. The pre- and postoperative data were compared to each other using paired t tests (α = 0.05).

Results

The patients had significantly less ROM after the surgery in all planes of motion. Major reduction was observed in flexion (39.5%), left and right lateral flexion (25.7 and 25.9%), with relatively minor impact on extension (18.3%), left and right rotation (14.0 and 14.4%) observed. In the three cardinal planes, major reduction was observed in the sagittal plane (28.2%) and coronal plane (25.8%), while minor impact observed in the horizontal plane (14.1%).

Conclusions

The patients of cervical spondylotic myelopathy had an obvious reduction in active cervical ROM following multilevel ACDF. However, patients might not experience great difficulties in performing daily activities with regard to the loss of neck motion after fusion.     

Surgically treated cervical myelopathy: a functional outcome comparison study between multilevel anterior cervical decompression fusion with instrumentation and posterior laminoplasty

Background contextMultilevel cervical myelopathy can be treated with anterior cervical discectomy and fusion (ACDF) or corpectomy via the anterior approach and laminoplasty via the posterior approach. Till date, there is no proven superior approach.PurposeTo elucidate any potential advantage of one approach over the other with regard to clinical midterm outcomes in this study.Study designA prospective, 2-year follow-up of patients with cervical myelopathy treated with multilevel anterior cervical decompression fusion and plating and posterior laminoplasty.Patient sampleIn total, 116 patients were studied. Sixty-four patients underwent ACDF two levels and above or anterior cervical corpectomy and fusion one level and above. Fifty-two patients underwent posterior cervical surgery (laminoplasty C3–C6 and C3–C7).Outcome measuresSelf-report measures: Japan Orthopedic Association (JOA) score, JOA recovery rate, visual analog scale for neck pain (VASNP), neck disability index (NDI), and American Academy of Orthopaedic Surgeons (AAOS) neurogenic symptom score (AAOS-NSS). Physiologic measures: range of motion (ROM) flexion and extension of neck. Functional measures: short-form 36 (SF-36) score comprising physical functioning, physical role function, bodily pain, general health, vitality, social role function, emotional role function, and mental health scales.MethodsComparison of the JOA scores, JOA recovery rates, NDI scores, SF-36 scores, VASNP, and ROM preoperatively to 2 years. Chi-square and two-sided Student t tests were used to analyze the variables.ResultsPosterior surgery took an hour shorter (p<.05) and had better improvement in JOA scores at early follow-up of 6 months (p=.025). Anterior surgery group had better improvement of NDI scores at early follow-up of 6 months (p=.024) and was associated with less blood loss intraoperatively compared with posterior surgery. There was no statistical difference between the two groups for JOA scores, JOA recovery rates, SF-36 quality-of-life scores, NDI, AAOS-NSS, VAS neck pain, and ROM at 2 years. Complications were higher for anterior surgery group: two hematoma postoperation, one vocal cord paresis, and one new onset C6/C7 dermatome numbness versus one dura leak in posterior surgery group.ConclusionsOur study showed that patients with multilevel disease treated with laminoplasty do well and compare favorably with patients treated with an anterior approach. Notably, posterior surgery was associated with shorter operating time, better improvement in JOA scores at 6 months, and a tendency toward lesser complications. Posterior surgery was not associated with increased neck disability and neck pain at 2 years. Anterior surgery had better NDI improvement at early follow-up. There is a need for a larger study that is prospectively randomized with long-term follow-up before we can confidently advocate one approach over the other in the management of cervical myelopathy.     

颈前路减压融合术治疗多节段颈椎病

目的报告颈前路减压融合术治疗多节段颈椎病的手术方法及临床疗效。方法回顾性分析自2003年8月-2008年1月期间,采用前路减压融合术治疗并获随访的28例多节段颈椎病患者,具体方法为间隙减压+椎体次全切除减压,取三面皮质自体髂骨或钛质网及椎间融合器(cage)填充切除病椎之松质骨置入,钢板固定。手术前后对患者进行JOA评分并计算改善率,并记录患者并发症。结果本组患者术中无并发症,随访18月～72个月。术后18月JOA评分平均改善率为75.2%,其中优11例,占39.3%;良9例,占32.1%;中8例,占28.6%;结论采用该术式的颈前路融合术治疗多节段颈椎病,减压直接彻底,恢复和重建颈椎生理曲度和病变节段椎间高度,坚强固定达到即刻稳定,疗效比较满意。     

Biomechanical analysis of cervical multilevel oblique corpectomy: an in vitro study in sheep

Summary Background. Anterolateral oblique corpectomy is an alternative approach to treatment of multilevel cervical spinal disease. It is stated that the approach does not cause instability in the patients with hard discs, so fusion or instrumentation is not required. The authors undertook a study on stability of the cervical spine by an animal model to establish if this approach causes instability.Material and methods. Thirty-seven C3 to C6 spinal segments obtained from 3 to 4-year-old male sheep were used. In vitro maximal loading values were obtained from seven sheep cervical specimens for flexion, extension, lateral flexion in both directions, axial rotation in both directions and axial loading, and load deformation curves were drawn by an electrohydrolic testing machine. Other specimens were divided into three groups: Control (n=10), C4 (n=10) and C4–5 (n=10) groups. In two study groups, one or two level oblique corpectomies were performed. In the control and study groups, biomechanical tests were obtained according to the maximal loading values. Load-deformation curves were drawn and displacement amounts were determined for all seven movements.Results. No statistically significant differences were observed in load deformation curves and displacement amounts between all three groups for seven movements.Conclusion. These results support the opinion that anterolateral oblique corpectomy does not cause cervical instability.     

前路分节段减压植骨融合术治疗多节段颈椎病的疗效分析

目的：评价前路分节段减压植骨融合术治疗多节段颈椎病的临床疗效.方法：对25例连续三节段病变的颈椎病患者采用分节段单间隙减压＋单椎体次全切除植骨融合内固定术治疗,分析手术时间、术中出血量、住院时间及住院费用、术后3个月植骨融合率、JOA评分改善率,并与同期由同一组医师采用两椎体次全切除长节段植骨融合内固定术的11例患者比较.结果：两组患者术后3个月随访时JOA评分均有不同程度提高,改善率无明显差异;分节段减压手术组平均手术时间、术中平均出血量、平均住院时间均低于长节段减压组,两者在统计学上有显著性差异;分节段减压手术组术后3个月植骨融合率为100%,高于长节段减压组（91%）,且无植骨块延期融合、内置物下沉等并发症发生,但两组间无统计学差异.结论：颈前路分节段减压植骨融合术治疗多节段颈椎病是较好的手术方式,具有更多优点.     

The arthrodesis rate in multilevel anterior cervical fusions using autogenous fibula

STUDY DESIGN: This study was a roentgenographic review of 145 patients who underwent multilevel anterior cervical arthrodesis using autogenous fibula. OBJECTIVE: To determine the arthrodesis rate in multilevel cervical fusions using autogenous fibula. SUMMARY OF BACKGROUND DATA: Previous studies have shown an unacceptably high rate of nonunions with multilevel anterior cervical arthrodesis. However, this has not been the clinical experience of the author's group. METHODS: Lateral roentgenograms taken a minimum of 2 years after surgery were reviewed independently by two radiologists. If either radiologist questioned any fusion level, the final decision was made on the basis of flexion-extension roentgenograms. RESULTS: An overall union rate of 90% and 94% per patient was found for each level of attempted fusion. A solid arthrodesis was achieved in 93% of the patients with two-level fusions, and 84% of the three-level fusions were solid. The difference was not statistically significant. CONCLUSION: Autogenous fibula used as a strut graft results in an acceptable union rate for multilevel anterior cervical arthrodesis.     

Delayed esophageal injury without instrumentation failure: complication of anterior cervical instrumentation

The authors describe a case of a 67-year-old man who presented with a delayed esophageal perforation 4 years after anterior cervical spine surgery for spondylotic myelopathy. Diagnosis was made with esophagoscopic visualization of the lesion and repair performed with hardware removal and esophageal closure utilizing a sternocleidomastoid muscle flap. The pertinent literature is reviewed and the therapeutic implications discussed.     

An analytical investigation of the mechanics of spinal instrumentation

Three-dimensional nonlinear finite element models of the intact L4-5 one motion segment/two-vertebrae and L3-5 two motion segments/three-vertebrae were developed using computed tomography (CT) films. The finite element mesh of the L4-5 motion segment model was modified to simulate bilateral decompression surgery. The mesh was further altered to achieve stabilization, using an interbody bone graft and a set of Steffee plates and screws. The model behavior of the intact specimen in all loading modes and of the stabilized model in compression, flexion, and extension modes were studied. The stresses in the cancellous bone region were found to decrease. The interbody bone graft, due to an overall decrease in stresses in the bone below the screw, transmits about 80% of the axial load as compared with 96% transmitted by an intact disc in an intact model. Thus, the use of a fixation device induces a stress shielding effect in the vertebral body. The results indicate that although the bone graft transmits lesser loads than the intact disc, it is active in transmitting loads. The presence of low stresses in the cancellous bone region and high localized stresses in the cortical pedicle region surrounding the screw, compared with the intact case, suggests that the screws are likely to become loose over time. The use of an interbody bone graft alone or in combination with any existing fixation device also induces higher stresses at the adjacent levels. This may be responsible for the adverse iatrogenic effects seen clinically.     

The clinical efficacy of short-term steroid treatment in multilevel anterior cervical arthrodesis

Background contextDysphagia is the most common complication of anterior cervical discectomy and fusion (ACDF), and it is closely related to prevertebral soft-tissue swelling (PSTS). A few studies have found that local or systemic methylprednisolone is effective against laryngopharyngeal edema and airway obstruction.PurposeTo assess the effectiveness of short-term use of systemic methylprednisolone in relieving dysphagia and decreasing PSTS during the hospitalization period.Study designA prospective study.Patient sampleForty patients who underwent multilevel (more than three levels) ACDF with same plate fixation.Outcome measureRadiologic and clinical measures.MethodsTwenty of these patients were given 250 mg of methylprednisolone intravenously (IV) four times a day only for 24 hours after the operation (at 6-hour intervals), whereas the remaining 20 did not receive methylprednisolone and served as controls. We used the Bazaz scale to compare the degree of dysphagia between groups during the hospitalization period. We used the C-spine lateral view to assess the degree of pre- and postoperative PSTS from C2 to C7. At the final follow-up, we assessed the relationship between the occurrence of complications and steroid use.ResultsThe degree of dysphagia according to the Bazaz scale was less severe in the group that received methylprednisolone (p values; postoperative Day [POD] 2～5<.05, POD 6=.014, POD 7=.019). Prevertebral soft-tissue swelling was also significantly lower in the group that received methylprednisolone (p values; POD 2～POD 5 <.005, POD 1=.061, POD 6=.007, POD 7=.091). The amount of PSTS and dysphagia did not differ according to sex, age, smoking history, or length of surgery. The period of hospitalization in the experimental group was shorter than in the control group. No complications related to steroid use were found at the final follow-up.ConclusionsThe short-term use of systemic methylprednisolone after ACDF appears to be effective in relieving dysphagia and decreasing the PSTS. Furthermore, the short-term use of methylprednisolone was not associated with any adverse effects of short-term IV steroid usage, such as peptic ulcer disease or postoperative infection. The clinical use of methylprednisolone in relieving dysphagia and decreasing PSTS deserves consideration during the early postoperative period.     

不同手术方式对多节段连续型脊髓型颈椎病的疗效分析

目的探讨不同手术方式对多节段连续型脊髓型颈椎病疗效的影响。方法选取多节段连续型脊髓型颈椎病48例,排除畸形和创伤病例。根据颈椎曲度不同,分为颈椎曲度正常组和异常组;根据所采取的手术方式不同,分为单间隙减压融合结合椎体次全切除术组、连续椎体次全切除术组以及全椎板切除术组;以术前、术后JOA评分为评估指标进行对比研究。结果在3组术前JOA评分差异无统计学意义（P〉0．05）的情况下,单间隙结合椎体次全切除术组术后JOA评分与其他2组相比,差异均有统计学意义（P〈0．01）。在颈椎曲度正常组中,连续椎体次全切除术组与全椎板切除术组术后JOA评分差异无统计学意义（P〉0．05）;颈椎曲度异常组中,连续椎体次全切除术组与全椎板切除术组术后JOA评分比较,差异有统计学意义（P〈0．01）。结论不同的手术方式对多节段连续型脊髓型颈椎病的疗效不同。在没有手术禁忌的情况下．颈椎前路手术特别是单间隙减压融合结合椎体次全切除术具有更好的手术疗效．     

Anterior instrumentation in thetreatment of lower cervical spine injuries

Anterior cervical instrumentation is a valuable adjunct to bony fusion techniques in obtaining internal stability to thecervical spine following trauma. Anterior plate fixator may obviate the need for a subsequent posterior procedure in cases of associated posterior cervical ligamentous instability, decrease the potential for loss of alignment or deformity, prevent graft dislodgment, and minimize the need for restrictive external immobilization for easier rehabilitation.     

Treatment of multilevel cervical fusion with cages

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

多节段脊髓型颈椎病的前路手术治疗

目的探讨多节段脊髓型颈椎病经前路行减压、植入椎间融合器（Cage）、钢板内固定术的治疗效果。方法对31例多节段脊髓型颈椎病均行经颈前路减压、植入Cage钢板内固定术。结果31例均获得随访,时间18～36（23±1.5）个月,椎间隙在15～24周内融合,术中减压较彻底,术后恢复融合节段间隙高度,未出现再丢失现象,颈椎生理曲度维持良好,椎间融合率达100%。未发生邻近节段退变。结论经颈前路行减压、植入Cage加钢板内固定治疗多节段脊髓型颈椎病效果满意,但对邻近节段退变现象仍需长期观察。