Risks and cost-effectiveness of sublaminar wiring in posterior fusion of cervical spine trauma

A report on the use of sublaminar wiring in the fusions of 34 patients with cervical spine injuries is given. No neurologic deficits were incurred in the use of this technique. There were no wire failures nor clinically significant complications. When compared with other forms of instrumentation to achieve similar results, the use of sublaminar wire is the most cost-effective.     

Spinal Instrumentation With A Low Complication Rate

Background

Spinal instrumentation has become an increasing part of the armamentarium of neurosurgery and neurosurgical training. For noncontroversial indications for spine fusion the arthrodesis rate seems to be better. For both noncontroversial and controversial indications, the reported complication rate with spinal instrumentation tends to be greater than that with noninstrumented spine surgeries. These reported complications include a 2–3% neurologic injury rate, 3–45% reoperation rate for implant failure, and infection rates of 5–10%. Therefore, we report on 299 cases that have undergone spinal instrumentation placed exclusively by neurosurgeons with a very low complication rate.

Methods

Two hundred ninety-nine consecutive spinal instrumentation cases performed exclusively by neurosurgeons at Indiana University Medical Center were analyzed for complications related to spinal instrumentation. The spinal instrumentation placed consisted of 195 anterior cervical locking plates, 22 cases of posterior cervical instrumentation, 9 cases of combined anterior locking plates with posterior cervical instrumentation, 14 anterior thoraco-lumbar plates, 51 posterior thoraco-lumbar instrumentation cases, and 8 combined anterior/posterior thoraco-lumbar instrumentation cases.

Results

The mean follow-up is 40 months (6–95). There was one perioperative death unrelated to the spinal instrumentation. There were no neurologic injuries and there has been no hardware infection to date. There were two dural tears, three superficial wound infections, and three minor wound breakdowns successfully treated. Hardware complications included three cervical plate/screw extrusions reoperated, one cervical plate fracture reoperated, one posterior cervical screw backout not reoperated, one case of broken pedicle screws not reoperated, one vertebral body failure not reoperated, and one posterior rod case reoperated for excessive rod length and protrusion. The overall complication rate attributable to placement of spinal instrumentation was 10/299 (3%) with a reoperation rate of 2%. The arthrodesis rate was 298/299 (99%).

Conclusion

The complication rate for using spinal instrumentation can be less than previously reported. Lessons learned and discussed should reduce the rate even more. Spinal instrumentation is a safe and useful adjunct to fusion in treating degenerative, traumatic, infectious, and neoplastic diseases of the spine.     

Cervical fixation in the pediatric patient: our experience

The surgical management of cervical instability in children is a challenging issue. Although the indications for internal fixation are similar to those for adults, accurate pre-surgery study and sharp surgical techniques are necessary because of the size of such patients’ anatomy, their peculiar tissue biology and the wide spectrum of diseases requiring cervical fusion. Our case study is made up of 31 patients, 15 male and 16 female, with an average age of 7 years and 6 months (2 years and 6 months to 18 years) who underwent cervical fusion for instability. Their physical condition presented various different pathologies ranging from congenital deformity, systemic skeletal disease, tumors, trauma, post-surgery instability. We performed occipito-cervical fusion in 11 cases, 5 of which involved stabilization at the cranium–vertebral junction. We used instrumentation in 13 cases (3 sublaminar wiring, 10 rigid adult instrumentation). We used rigid adult instrumentation in three patients under 10 years of age, treated by rod, occipital screws and sublaminar hook instrumentation in steel C0–C2 (9-year-old male, affected by os odontoideum in Down’s syndrome; male of 7 years and 10 months, affected by os odontoideum in Down’s syndrome; female of 4 years and 6 months with occipito-cervical stenosis and C0–C2 instability in Hurler’s syndrome). We operated on two patients under 3 years of age, using sublaminar wiring with bone precursors and allograft at level C0–C2 (one of these was a 30-month-old male with post-traumatic instability C0–C2, while the other was a 17-month-old male with C0–C2 instability in Larsen’s syndrome). The average follow-up age was 7 years and 1 month (between 1 and 18 years). Cervical fusion was assessed by X-ray examinations at 4th and 12th weeks and at 6th and 12th months after surgery. Where implants could allow, RMN examination was performed at 1st month after surgery. In the other cases, in which implants do not allow RMN to be performed, CT scan and standard X-rays were carried out, and new X-rays were performed every other year. We experienced two cases of sublaminar wiring rupture without impairment of bone fusion. No patient suffered major complications (infection and osteomyelitis, rigid instrumentation mobilization, incomplete fusion with instability, neurologic impairment, insufficient cervical spine range of movement to cope with everyday life activities, cervical pain). Even though most authors still indicate that rigid instrumentation should be performed in cases over 10 years of age and sublaminar wiring in cases over 3 years of age, our findings demonstrate that this age limit can be lowered. We have treated children under 10 years of age by rigid adult instrumentation and under 36 months of age by wiring. The anatomic size of the patient is the most important factor in determining the use of instrument arthrodesis to treat pediatric cervical spine instability. Although not easy, it is possible and preferable in many cases to adapt fixation to child cervical spine even in very young patients.

     

The treatment of spinal fractures with Harrington compression rods and segmental sublaminar wiring. A dangerous combination

The increasing use of more rigid internal fixation constructs for spinal fractures, especially in association with spinal cord injury, has led surgeons to combine sublaminar segmental wiring with Harrington instrumentation systems. Two clinical cases whose neurologic condition deteriorated postoperatively were shown to have sustained direct cord injury by the combination of Harrington compression rods with segmental sublaminar wiring. Myelographic and surgical evidence of hook protrusion into the spinal canal with direct cord injury is presented. Laboratory spine simulations duplicating the clinical situation did demonstrate that sublaminar wiring of the Harrington compression rod system caused the standard hooks to protrude dangerously into the spinal canal. Caution should be exercised not to combine Harrington compression rods with segmental sublaminar wiring.     

Cervical fixation in the pediatric patient: our experience

The surgical management of cervical instability in children is a challenging issue. Although the indications for internal fixation are similar to those for adults, accurate pre-surgery study and sharp surgical techniques are necessary because of the size of such patients’ anatomy, their peculiar tissue biology and the wide spectrum of diseases requiring cervical fusion. Our case study is made up of 31 patients, 15 male and 16 female, with an average age of 7 years and 6 months (2 years and 6 months to 18 years) who underwent cervical fusion for instability. Their physical condition presented various different pathologies ranging from congenital deformity, systemic skeletal disease, tumors, trauma, post-surgery instability. We performed occipito-cervical fusion in 11 cases, 5 of which involved stabilization at the cranium–vertebral junction. We used instrumentation in 13 cases (3 sublaminar wiring, 10 rigid adult instrumentation). We used rigid adult instrumentation in three patients under 10 years of age, treated by rod, occipital screws and sublaminar hook instrumentation in steel C0–C2 (9-year-old male, affected by os odontoideum in Down’s syndrome; male of 7 years and 10 months, affected by os odontoideum in Down’s syndrome; female of 4 years and 6 months with occipito-cervical stenosis and C0–C2 instability in Hurler’s syndrome). We operated on two patients under 3 years of age, using sublaminar wiring with bone precursors and allograft at level C0–C2 (one of these was a 30-month-old male with post-traumatic instability C0–C2, while the other was a 17-month-old male with C0–C2 instability in Larsen’s syndrome). The average follow-up age was 7 years and 1 month (between 1 and 18 years). Cervical fusion was assessed by X-ray examinations at 4th and 12th weeks and at 6th and 12th months after surgery. Where implants could allow, RMN examination was performed at 1st month after surgery. In the other cases, in which implants do not allow RMN to be performed, CT scan and standard X-rays were carried out, and new X-rays were performed every other year. We experienced two cases of sublaminar wiring rupture without impairment of bone fusion. No patient suffered major complications (infection and osteomyelitis, rigid instrumentation mobilization, incomplete fusion with instability, neurologic impairment, insufficient cervical spine range of movement to cope with everyday life activities, cervical pain). Even though most authors still indicate that rigid instrumentation should be performed in cases over 10 years of age and sublaminar wiring in cases over 3 years of age, our findings demonstrate that this age limit can be lowered. We have treated children under 10 years of age by rigid adult instrumentation and under 36 months of age by wiring. The anatomic size of the patient is the most important factor in determining the use of instrument arthrodesis to treat pediatric cervical spine instability. Although not easy, it is possible and preferable in many cases to adapt fixation to child cervical spine even in very young patients.     

Surgery for Upper Cervical Spine Instabilities in Children

Summary. Summary. Background: Due to the paucity of existing data with regard to surgical fusion of upper cervical spine instabilities in the paediatric population, we feel encouraged to report the results of our own series to provide additional information to the available body of literature. Methods: Since 1991 N=11 children underwent a total of N=13 surgical procedures for N=8 posttraumatic, N=2 congenital and N=1 postinfectious instabilities at a mean age of 10 years (range: 3–16 years). Transoral odontectomies, ventral odontoid screw-fixations, dorsal wiring or -clamping and transarticular screw-fixations were performed for stabilization and iliac crest bone graft used for fusion. Pain scores, neurological status and radiological results were documented at regular intervals (mean follow-up: 25.4 months). Results: Stable fusion was achieved in all patients as documented on flexion/extension films and tomographies. At the latest follow-up N=2 patients had improved and N=9 were equal to their preoperative neurological status. Pain scores were improved in N=9 patients. N=2 children developed “bystander-fusion” after C0/2 wiring. N=3 peri-operative complications occurred as transient neurological deteriorations. In one case this resulted from the resection of a lower brainstem tumour prior to the stabilization procedure. One was attributed to sublaminar wiring in the case of an os odontoideum and one occurred due to slippage of the halo orthosis after transoral odontectomy before definitive dorsal stabilization was carried out. Interpretation: In accordance with the recent literature, we argue for the application of modern screw fixations and treatment algorithms as established for adults in upper cervical spine instabilities of older children. Techniques and indications remain problematic for those younger than 6 years and may have to be individualized in congenital instabilities.     

The effect of Luque-rod instrumentation on the sagittal contour of the lumbosacral spine in adolescent idiopathic scoliosis and the preservation of a physiologic lumbar lordosis.

The changes in the sagittal alignment of the lumbar spine were investigated in 28 patients with adolescent idiopathic scoliosis undergoing long posterior spinal fusion to L4 or L5 with contoured Luque rods and segmental sublaminar wiring. The lumbar lordosis over the instrumented levels was preserved, and there was no compensatory hyperlordosis of vertebral segments distal to the fusion. In situations where long posterior spinal fusions are indicated, instrumentation with contoured Luque rods and segmental sublaminar wiring can preserve the normal sagittal alignment of the lumbosacral spine.     

Aspects of spinal deformity in familial dysautonomia (Riley-Day syndrome)

Familial dysautonomia (FD) is a rare autosomal recessive disease occurring in Jews of Ashkenazi descent, with only some 500 recognized cases. The causative gene was identified on chromosome 9. FD is of considerable orthopedic interest, because of the prevalence of skeletal deformity. About 90% of surviving dysautonomic children will develop a spinal curvature, commonly a scoliliotis. The scoliotic curve is usually kyphotic rather than lordotic, and appears during the first decade of life. Fifty-one of the 90 reported cases of familial dysautonomia in Israel involved patients who were seen at the scoliliotis clinic for assessment and treatment of their spinal deformities. Most of the patients presented with a scoliotic deformity associated in 37 cases with an increased thoracic kyphosis. In our series orthotic treatment and physiotherapy were found to be minimally successful at best. Surgical treatment of the spine was performed in 13 of 51 patients in this series. A retrospective review of these patients' charts and radiographs was carried out. Six years of follow-up are reported. The primary indication for surgery was progression of the spinal curve. Only posterior spinal fusions were performed. Anterior transthoracic procedures were avoided in spite of the significance of the kyphotic deformity, because of the frequency of pulmonary complications. Harrington distraction and compression instrumentation was used. Three-millimeter compression rods were used in a distraction mode in thin, young children. Harri-Luque segmental sublaminar wiring technique and Wisconsin spinous process segmental wiring was used in some. In all cases, the spine fusion was supplemented by bank bone only, to avoid the additional trauma of graft removal. We believe that surgical intervention is advantageous, if done early in the evolution of spinal deformity. Greater technical difficulties and a higher complication rate were encountered in this series relative to the problems usually seen after spinal deformity surgery in children; this is all the more important in a disease in which general anesthesia is an additional major complicating factor. It is hoped that the improved physical condition now seen after early gastrostomy and fundoplication will aid in reducing this high complication rate. Only a small degree (about 25%) of correction was achieved in the majority of patients. Some of this apparent rigidity derived from the inability to apply sufficient instrumental corrective force because of the friable osteoporotic bone. After surgery, there was a marked decrease in the frequency of pneumonia and an improvement in the degree of ataxia, for reasons not understood, which led to an obvious improvement in the quality of life.     

A biomechanical evaluation of cervical spinal stabilization methods in a bovine model. Static and cyclical loading

A bovine model was developed for biomechanical evaluation of surgical procedures stabilizing traumatic cervical injuries disrupting the anterior and posterior spinal column. Cervical spinal segments and C4-5 functional spinal units were tested statically, and C4-5 functional spinal units were tested cyclically in evaluation of 1) the intact cervical spine, 2) Rogers' wiring method, 3) Bohlman's triple-wire technique, 4) sublaminar wiring, 5) anterior cervical plate instrumentation, and 6) posterior hook plate stabilization. Anterior cervical plate instrumentation proved inadequate, and was the least rigid, with axial and flexural loading (P less than 0.05). There was no significant difference between each of the three posterior wiring methods, and all generally restored stability to equal that of the uninjured intact cervical spine. Posterior hook plating with an interspinous bone graft serving as an extension block was the most effective method in reducing flexural stress across the injured C4-5 segment (P less than 0.05). Cyclical in vitro testing was the most sensitive method in highlighting mechanical differences between instrumentation systems, particularly with "on-line" continuous measurement of anterior and posterior strains. Anterior cervical plate stabilization does not appear to confer enough stability in cervical facet injuries to obviate the need for posterior cervical stabilization procedures. The recently developed posterior hook plate technique offers biomechanical advantages that should be weighed against the greater technical precision needed for insertion and the increased potential for neurologic and vascular complications.     

Die atlantoaxiale Kyphose

Atlantoaxial kyphosis (AAK) is a rare sagittal deformity of the occiptoatlantoaxial junction. It is defined as a subgroup of anterior translatory atlantoaxial instability. AAK is a symptom of several ligamentours or bony disorders of the craniocervical junction; however, rheumatoid arthritis and trauma are the most common causes for AAK. AAK can be diagnosed on lateral radiographic views of the upper cervical spine if the angle between McGregor's line and the atlas plane is less than-15 degrees or the atlas-axis angle is greater 105 degrees. Treatment modalities for AAK depend on the ability to reduce the deformity. If closed reduction is achieved, posterior atlantoaxial fusion by sublaminar wiring according to Brooks or transarticular screw fixation according to Magerl are possible choices. Irreducible AAK can be treated with a combined transoral decompression, anterior plating according to Harms, and posterior wiring according to Brooks. This staged therapy for AAK was successful in our rheumatoid patient population with AAK.     

Cotrel Dubousset instrumentation in occipito-cervico-thoracic fusion

There are today several techniques available for cervical fixation - all with inherent limitations and risks. In view of the drawbacks of wiring and screw fixation, which both presuppose good bone quality for stabilization, there is a need for a stable and safe fixation system that can also be used in osteoporotic bone. The objective of the present retrospective study was to assess the usefulness and safety of Cervical Cotrel Dubousset Instrumentation (CCDI), based on sublaminar hooks. The material comprises 60 consecutive patients, 28 men and 32 women, with a mean age of 57.3 years (range 17-84 years), operated on with CCDI. The diagnosis was trauma in 17 patients, rheumatoid arthritis in 16 patients, tumor in 20 patients and miscellaneous diagnoses in 7 patients. The material was dominated by severe pathologies, with neurological impairment in 17 patients (28%). Complications, subjective outcome and Frankel classification of neurological status pre- and postoperatively was documented. The patient outcome evaluation was excellent in 46%, good in 34%, fair in 10%, and poor in 10%. The physician's assessment was similar: 56% excellent, 27% good, 10% fair and 7% poor. Two patients improved by two Frankel grades, 7 by one and 47 patients had the same Frankel grade as preoperatively. Two patients deteriorated by one Frankel grade, one by three grades and one patient by four Frankel grades. Except for a 10% deep wound infection rate, there were few complications, with no evidence of neurological injury from the hooks in the spinal canal. The results of this study show that the cervical CDI system can be safely used for stable cervical fixation without need for external support in severe pathologies of the cervical spine.     

Sublaminar wiring stabilization to prevent adjacent segment degeneration after lumbar spinal fusion

Introduction  Adjacent segment degeneration (ASD) is a complication of lumbar spinal fusion. There are some reports on the cause of this degeneration but none concerning its prevention. We performed sublaminar wiring stabilization to prevent ASD after posterolateral lumbar spinal fusion with instrumentation. The purpose of this study was to prospectively evaluate the efficacy of this procedure. Patients and methods  Between 2003 and 2004, 54 consecutive patients with lumbar spinal canal stenosis and multilevel instability of the lumbar spine underwent posterior decompression and posterolateral fusion with instrumentation. The mean age at the time of surgery was 66.7 ± 1.3 years, and the mean follow-up period was 40.0 ± 1.1 months, with a minimum of 29 months. Twenty-seven of the patients underwent conventional sublaminar wiring stabilization at the cephalad segment adjacent to the site of fusion to prevent ASD (group A), and the other 27 patients did not (group B). Some items were assessed, including clinical outcome using Japanese Orthopaedic Association (JOA) score, sagittal global lumbar alignment, and segmental motion in flexion–extension radiographs of the cephalad vertebral body adjacent to the site of fusion. Results  There were no significant differences in JOA scores between two groups, but 2 patients in group B underwent subsequent surgery due to ASD. Sagittal lumbar alignment did not change in group A but was significantly decreased in group B. With respect to segmental motion in flexion–extension radiographs, group A showed a significant decrease from 6.9° before surgery to 3.4° after surgery, on the other hand group B showed a significant increase from 5.6° before surgery to 8.4° after surgery. Conclusions  In this study, it was suggested that sublaminar wiring stabilization significantly reduces the range of motion of the adjacent segment and preserves sagittal lumbar alignment, which lead to prevention of ASD. The clinical outcome of the subsequent surgeries is relatively poor, so it is important to prevent ASD by any prevention such as sublaminar wiring stabilization.     

A biomechanical study of 3 different types of sublaminar wire used for constructs in the thoracic spine

A biomechanical study was carried out on 3 different types of sublaminar wire used in constructs to secure the thoracic spine: stainless steel monofilament wire (steel wire), titanium cable (cable), and ultra-high molecular weight polyethylene tape (tape). Two experiments were carried out. Experiment 1: Thirty-one fresh human thoracic vertebrae classified as osteoporotic (bone mineral density of <0.8 g/cm2) were used. The steel wire, cable, or tape was placed sublaminarly and a tensile force was applied until the steel wire, cable, or tape cut 5 mm through the lamina, and the force at this point was noted. Experiment 2: Seven fresh human thoracic spines (T7-T10) were biomechanically tested as follows: axial compression (250 N), flexion (7.5 Nm), extension (7.5 Nm), left lateral bending (7.5 Nm), right lateral bending (7.5 Nm), left axial torsion (10 Nm), and right axial torsion (10 Nm). This sequence was applied to the intact spine. The spine was then de-stabilized and then restabilized using one or other of the 3 different types of sublaminar wires. The biomechanical testing was then repeated on the restabilized spine and stiffness curves were generated. In the laminar cut-through test, the cut-through force for tape was higher than that for either steel wire or cable. In the biomechanical stiffness testing, there was no significant difference between the 3 different sublaminar wiring constructs in any of the loading modes tested. The results of both experiments suggest that tape is as good, if not better, than steel wire or cable as a sublaminar wiring construct material.     

Fusion of scoliosis by Harrington distraction rod: Interspinous process and sublaminar wiring compared in 42 cases

Forty-two consecutive patients with scoliosis who between 1981 and 1988 underwent posterior Harrington distraction rod and interspinous process or sublaminar wiring were retrospectively reviewed. No difference was found between the techniques with respect to age, sex, curve pattern, curve magnitude, levels fused, operative time, blood loss, correction, and loss of correction at the 1-year and 2-year follow-up. The interspinous process wiring was superior to the sublaminar wiring as regards ease of technique, early ambulation, few complications, and a more effective means for maintaining the correction without postoperative immobilization.     

Fusion of scoliosis by Harrington distraction rod. Interspinous process and sublaminar wiring compared in 42 cases.

Forty-two consecutive patients with scoliosis who between 1981 and 1988 underwent posterior Harrington distraction rod and interspinous process or sublaminar wiring were retrospectively reviewed. No difference was found between the techniques with respect to age, sex, curve pattern, curve magnitude, levels fused, operative time, blood loss, correction, and loss of correction at the 1-year and 2-year follow-up. The interspinous process wiring was superior to the sublaminar wiring as regards ease of technique, early ambulation, few complications, and a more effective means for maintaining the correction without postoperative immobilization.     

Delayed paraplegia complicating sublaminar segmental spinal instrumentation

The cases of two patients with delayed paraplegia after segmental spinal instrumentation with sublaminar wiring are reported. Both patients had complex spinal deformities and had transient neural deficits after the first-stage procedure of anterior release and spine fusion. They had uneventful spinal-cord monitoring during the second-stage procedure of posterior instrumentation and fusion, and function of the lower extremities was present immediately after that operation. Paraplegia then ensued, and was recognized thirty hours later in one patient and six days later in the other. Considering our reproducible and reliable experience (no false-negative results) with spinal cord monitoring in 307 operations, we propose that the delayed onset of paraplegia resulted from a progression of ischemic and edema-producing events that had not developed sufficiently intraoperatively to be reflected by the monitoring. The paraplegia became evident only when the subarachnoid space was obstructed because of progressive postoperative neural edema. The presence of sublaminar implants in narrow, kyphotic segments of the spinal canal probably exacerbated the neural irritation by dural impingement, which was seen myelographically.     

Stability of different wiring techniques in segmental spinal instrumentation

The pullout force of sublaminar and transspinous wires for segmental instrumentation which had been inserted into different segments of human cadaver spines were campared. Four different types of wiring were tested: single and double sublaminar wires, button-wires according to Drummond's technique and button-wires with the additional use of two crimps for each spinous process. A total of 50 tests were performed. In all attempts the bone proved to be the limiting factor. None of the 300 fixed wires failed. Typical types of fractures appeared with different wiring techniques. There was no statistically significant difference between the sublaminar wiring techniques tested. However, there were significant differences between sublaminar and transspinous wiring. The transspinous techniques achieved between 30% and 45% of the pull-out strength of sublaminar techniques. The forces decreased with increasing cranialisation. In all techniques the values in the upper segment (D5–D3) were almost half those of the lower segment (L5–L3). The differences of the transspinous techniques increased cranially, in favour of the technique with additional crimps. Thus, the crimps have the strongest effect on weak spinous processes. This study demonstrates that in non-dynamic testing, the stability of the bone and not the type of wiring is the limiting parameter in segmental spinal stabilisation. As the wires are inserted in different areas, the transspinous technique shows significantly lower tension forces in comparison with sublaminar wiring.     

Posterior cervical fusion with triple-wire strut graft technique: one hundred consecutive patients.

One hundred consecutive patients were treated by the triple-wire stabilization and fusion technique for acute cervical trauma (36 patients), rheumatoid arthritis (27 patients), degenerative osteoarthritis (20 patients), congenital deformities (13 patients), or neoplasms (11 patients). The triple wire technique developed by Bohlman is versatile enough to be used at any level of the cervical spine, with 60 patients undergoing subaxial fusions, 20 with atlantoaxial fusions, and 20 with stabilization to the occiput. The immediate stability is evidenced by the fact that only two of 60 subaxial triple-wire stabilizations required the use of a Halovest, 58 being managed postoperatively in two-poster orthosis. The fusion rate was 100% for subaxial fusions. The only pseudarthrosis occurred in an occiput to C2 triple wire fixation procedure, which was managed nonoperatively. There were no iatrogenic neurologic complications, unlike the use of techniques utilizing sublaminar wires, and there were no cervical infections.     

Bone morphogenetic protein in complex cervical spine surgery: A safe biologic adjunct?

The advent of recombinant DNA technology has substantially increased the intra-operative utilization of biologic augmentation in spine surgery over the past several years after the Food and Drug Administration approval of the bone morphogenetic protein (BMP) class of molecules for indications in the lumbar spine. Much less is known about the potential benefits and risks of the “off-label” use of BMP in the cervical spine. The history and relevant literature pertaining to the use of the “off-label” implantation of the BMP class of molecules in the anterior or posterior cervical spine are reviewed and discussed. Early prospective studies of BMP-2 implantation in anterior cervical spine constructs showed encouraging results. Later retrospective studies reported potentially “life threatening complications” resulting in a 2007 public health advisory by the FDA. Limited data regarding BMP-7 in anterior cervical surgery was available with one group reporting a 2.4% early (< 30 d) complication rate (brachialgia and dysphagia). BMP use in the decompressed posterior cervical spine may result in neurologic or wound compromise according to several retrospective reports, however, controlled use has been reported to increase fusion rates in select complex and pediatric patients. There were no cases of de novo neoplasia related to BMP implantation in the cervical spine. BMP-2 use in anterior cervical spine surgery has been associated with a high early complication rate. Definitive recommendations for BMP-7 use in anterior cervical spine surgery cannot be made with current clinical data. According to limited reports, select complex patients who are considered “high risk” for pseudoarthrosis undergoing posterior cervical or occipitocervical arthrodesis or children with congenital or traumatic conditions may be candidates for “off-label” use of BMP in the context of appropriate informed decision making. At the present time, there are no high-level clinical studies on the outcomes and complication rates of BMP implantation in the cervical spine.     

颈前路减压支撑融合钢板内固定术治疗脊髓型颈椎病

目的 探讨颈前路减压、椎体间植骨支撑融合或颈椎椎间融合器（钛网或Cage）支撑融合、钢板内固定术治疗脊髓型颈椎病的临床方法及疗效。方法 回顾分析66例脊髓型颈椎病患者行颈前路减压后,分别采取骼骨植骨支撑融合、颈椎间融合器（钛网或Cage）植入支撑融合,钢板内固定术,随访时间平均32个月,采用Zdeblick影像学判定椎体间融合的标准,贾连顺的评定法评定术后临床疗效。结果 在颈前路减压、钢板内固定术治疗脊髓型颈椎病方法中,自体骼骨植骨融合优良率87．5％,供区并发症12．1％,椎间盘退变椎问高度丢失7．6％;颈椎间融合器支撑融合优良率96．1％,无供区并发症和椎问盘退变椎间高度丢失。结论 颈前路减压、椎体间植骨融合或颈椎间融合器支撑融合、钢板内固定术治疗脊髓型颈椎病临床疗效满意。钢板内固定术后颈椎即刻稳定;植骨融合手术操作简单,费用少,但存在供区并发症、椎问高度丢失;椎间融合器融合稳定、牢固,椎间高度丢失少,后者疗效优于前者。