Comparison between anterior cervical discectomy and fusion using zero-P and traditional anterior cervical plate plus cage for treating two-level cervical spondylosis / 中国组织工程研究

BACKGROUND: Anterior cervical discectomy and fusion is a classic surgical procedure for the treatment of cervical spondylosis. At present, we can use a Zero-P interbody fusion fixture and a traditional cervical anterior plate plus cage as an internal fixation material. The Zero-P has less postoperative esophageal interference and lower incidence of postoperative dysphagia compared with traditional anterior cervical plate fixation. Besides, the Zero-P could avoid the risk of excessively long or pooriy placed plate injury to adjacent segmental intervertebral discs. OBJECTIVE: To compare the safety and effectiveness between two-level anterior cervical discectomy and fusion using Zero-P and using traditional anterior cervical plate plus cage. METHODS: Clinical data of sixty patients who underwent two-level anterior cervical discectomy and fusion in the Chengdu Third People’s Hospital from May 2016 to May 2018 were retrospectively analyzed. The patients were divided into Zero-P group (Zero-P fusion, n=30) and plate group (anterior cervical plate fixation combined with cage implantation, n=30). All patients in the two groups had informed consent to the treatment plan. This study was approved by the hospital ethics committee. The Japanese orthopedic association score, neck disability index score and Bazaz swallowing function score were used to evaluate the clinical efficacy. Cervical X-ray and cervical CT scans were performed to assess cervical curvature, observe bone graft fusion, and implant displacement, loosening and breakage. RESULTS AND CONCLUSION: (1) All surgeries were successfully completed in 60 patients. The wounds healed in stage I after operation. There were no serious complications such as nerve injury, esophageal fistula, and cerebrospinal fluid leakage. (2) During the follow-up, there was no significant difference in neck disability index, Japanese orthopedic association score and bone graft fusion rates between the two groups (P > 0.05). (3) The incidence and severity of dysphagia in the Zero-P group were lower than those in the plate group at various time points after operation (all P < 0.05). (4) The overall curvature and operative segments curvature were better in the plate group than in the Zero-P group 6 months after surgery and in final follow-up (P < 0.05). (5) Two-level anterior cervical discectomy and fusion using Zero-P is a safe and effective operative method. The operation time, bleeding volume, number of fluoroscopy and postoperative dysphagia incidence were better than the traditional anterior cervical plate plus cage fixation system, but it is not as good as the traditional anterior cervical plate plus cage system in the curvature of the cervical spine. Zero-P is not recommended for patients with obvious abnormal cervical curvature before operation.

Clinical Efficacy of Cages in Anterior Cervical Fusion for Degenerative Cervical Disease

STUDY DESIGN: Review of the literature.OBJECTIVES: To present up-to-date information on the use of cages in anterior cervical fusion for degenerative cervical disease.SUMMARY OF LITERATURE REVIEW: The use of cages in anterior cervical fusion for degenerative cervical disease remains controversial.MATERIALS AND METHODS: Review of the relevant literature.RESULTS: The use of cages in anterior cervical fusion of one and multiple disc levels was effective in terms of biomechanical stability and clinical outcomes without complications at the donor site compared with use of an autograft. However, the use of only a cage had many drawbacks, so the combined use of a cage and a cervical plate is recommended.CONCLUSIONS: The use of cages in anterior cervical fusion was effective in terms of clinical outcomes, and the combined use of a cage and a cervical plate is recommended.

Biomechanical Comparison Analysis of Cervical Plate Systems for Anterior Cervical Discectomy and Fusion: Constrained vs. Semi-constrained Systems / 대한골다공증학회지

The purpose of this study were to constructed multi-level cervical spine finite element (FE) model and to investigate changes in load distribution and range of motion (ROM) at index level and adjacent levels at immediately after anterior cervical discectomy and fusion (ACDF) and after full bony union using constrained and semi-constrained cervical plate systems(dynamic plate, variable screw). A FE model of intact cervical spine (C3-6) was created from computer tomography (CT) images of the healthy adult (male, 26 years, no pathologies). The post-op FE models (C5-6 with ACDF, cage with bone graft) were constructed by modifying a intact cervical FE model. Four different configurations of the model were considered: Type 1-Rigid plate+Fixed screw, Type II-Rigid plate + Variable screw, Type III-Dynamic plate + Fixed screw, Type IV-Dynamic plate + Variable screw. The bone-cage and bone screw interface behavior were accomplished via 'tie' contact condition and friction coefficient of 0.2 to assume fusion and non-fusion, respectively. The inferior endplate of C6 vertebral body was constrained in all directions. Loading condition used hybrid protocol with follower load of 73.6N at superior endplate of C3 vertebral body. In non-fusion cases, load at the bone graft increased from Type I to IV (2.3

A goat model for research of anterior cervical-adjustable fusion fixator / 第二军医大学学报

Objective: To establish an animal model for anterior cervical-adjustable fusion fixator (AC-AFF), and to compare the operation time, blood loss, and recovery time of food intake and movement between AC-AFF group and other groups with different cervical reconstruction fixators. Methods: Eighteen goats were evenly randomized into 3 groups: AC-AFF, steel plate+ titanium mesh, and steel plate+autogenous iliac bone group. The 3 fixtors were implanted after corpectomy. The operation time, blood loss during operation, and recovery time of food intake and movement were recorded in each animal and were compared. Results: All experiment animals survived after operation; one animal of steel plate+titanium mesh group suffered from incision infection and recovered 5 days after intramuscular penicillin therapy. Two animals in steel plate+autogenous iliac bone group could not stand on forehoof, but food intake was not influenced; the animals could stand 1 week later without treatment and walked with difficulty, and they recovered normal walk 2 weeks later. Four animals received C3 corpectomy (2 received AC-AFF and 2 received steel plate+titanium mesh) and the rest received C4 corpectomy. It was found that AC-AFF group had the shortest operation time (P<0.01), and there was no difference between the other 2 groups. The intra-operation blood loss in the steel plate+autogenous iliac bone group was significantly higher than that in the other 2 groups (P<0.01), with no significant difference found between the latter 2 groups. Conclusion: AC-AFF is easier to manage than the other 2 fixators; besides, AC-AFF has less blood loss, short operation time, less post-operation complication, and early recovery of food intake and movement.

Two-Level Anterior Cervical Discectomy and Fusion with Stand-alone Cages in Cervical Spinal Degenerative Diseases

OBJECTIVE: Anterior cervical discectomy and fusion(ACDF) is a highly successful surgical treatment for nerve root or spinal cord compression caused by disc herniation or spondylosis. Multilevel cervical discectomy usually requires plate and screw fixation for adequate bony fusion and stability. But the use of plate and screw fixation may cause some post-operative complications. So in this study we evaluate the safety and effectiveness of two-level ACDF with carbon or polyetheretherketone(PEEK) cages without cervical plate in cervical degenerative disc disease. METHODS: We retrospectively analyzed 18 patients who underwent two-level ACDF with carbon or PEEK cages from February 2002 to August 2008. The mean follow-up period was 31months. Clinical, radiologic and surgical morbidities were assessed in all cases. Outcome assessment was done using Odom's criteria and visual analogue scale(VAS) score. Radiological assessment was done with bony fusion rate, linear measure of cervical lordosis, cervical lordotic angle and cage subsidence. RESULTS: Radiculopathy was improved in all cases(100%) after surgery, whereas myelopathy was resolved in three of five patients(60%). Radiographic evidence of fusion was found in all patients(100%) at last follow-up. Preoperative mean VAS score was 8.1 compared with a postoperative score 2.5(p<0.05). The clinical outcome was excellent or good in 16 cases(89%). There were no serious complications such as dislodgement of cages, hardware failure, infection and neurologic deterioration. Linear measure of cervical lordosis at last follow-up was increased from 2.72+/-1.12mm to 7.84+/-1.09mm. Cervical lordotic angle at last follow-up was increased from 8.9+/-2.76 degrees to 15.1+/-2.38 degrees. The mean loss of disc height was 1.40mm during the follow-up period. However development of subsidence did not influence on clinical outcomes. CONCLUSION: ACDF in two-level stand-alone cages is a safe and effective procedure in multilevel cervical degenerative diseases. In spite of subsidence, interbody fusion with cages provides load-sharing function and stabilization of the cervical spine by increasing segmental rigidity, thus yielding excellent fusion rates and less graft failure, even in two- level cervical diseases.

Clinical study on transplantation of iliac allograft with plate in the cervical single level anterior operation / 中国矫形外科杂志

[Objective]To investigate the application value of the iliac allograft combined with anterior plate in the cervical anterior operation.[Method]Sixty-eight cases of anterior cervical decompression and fusion were performed with the iliac allograft combined with anterior plate.The data such as operative time,blood loss during operation and continue X-ray on their cervical spine were recorded,and were compared with the correspondent data of the control group which were transplanted of the iliac autograft combined with anterior plate.[Result]Compared with that of the control group(iliac autograft combined with anterior plate),the operative time and blood loss during operation in the group of iliac allograff combined with anterior plate was less(P

Biomechanical Testing of Anterior Cervical Spine Implants: Evaluation of Changes in Strength Characteristics and Metal Fatigue Resulting from Minimal Bending and Cyclic Loading

OBJECTIVE: To achieve optimal fit of implant, it is necessary to bend the implant during spine surgery. Bending procedure may decrease stiffness of plate especially made of titanium and stainless steel. Typically titanium suffers adverse effects including early crack propagation when it is bent. We investigate whether 6 degree bending of titanium plates would decrease the stiffness after full cyclic loading by comparing with non-bending titanium plates group. METHODS: Authors experimented 40 titanium alloy plates of 57mm in length, manufactured by 5 different companies. Total 40 plates were divided into two groups (20 bent plates for experimental group and 20 non-bent plates for control group). Twenty plates of experimental group were bent to 6 degree with 3-point bending technique and verified with image analyzer. Using the electron microscope, we sought for a initial crack before and after 3-point bending. Mechanical testing by means of 6000 cyclic axial-compression loading of 35N in compression with moment arm of 35mm-1.1Nm was conducted on each plate and followed by the electron microscopic examination to detect crack or fissure on plates. RESULTS: The stiffness was decreased after 6000 cyclic loading, but there was no statistically significant difference in stiffness between experimental and control group. There was no evidence of change in grain structure on the electron microscopic magnification. CONCLUSION: The titanium cervical plates can be bent to 6 degree without any crack or weakness of plate. We also assume that minimal bending may increase the resistance to fatigue fracture in cervical flexion-extension movement.

A Biomechanical Comparison among Three Surgical Methods in Bilateral Subaxial Cervical Facet Dislocation

OBJECTIVE: The biomechanical stabilities between the anterior plate fixation after anterior discectomy and fusion (ACDFP) and the posterior transpedicular fixation after ACDF(ACDFTP) have not been compared using human cadaver in bilateral cervical facet dislocation. The purpose of this study is to compare the stability of ACDFP, a posterior wiring procedure after ACDFP(ACDFPW), and ACDFTP for treatment of bilateral cervical facet dislocation. METHODS: Ten human spines(C3-T1) were tested in the following sequence: the intact state, after ACDFP(Group 1), ACDFPW(Group 2), and ACDFTP(Group 3). Intervertebral motions were measured by a video-based motion capture system. The range of motion(ROM) and neutral zone(NZ) were compared for each loading mode to a maximum of 2.0Nm. RESULTS: ROMs for Group 1 were below that of the intact spine in all loading modes, with statistical significance in flexion and extension, but NZs were decreased in flexion and extension and slightly increased in bending and axial rotation without significances. Group 2 produced additional stability in axial rotation of ROM and in flexion of NZ than Group 1 with significance. Group 3 provided better stability than Group 1 in bending and axial rotation, and better stability than Group 2 in bending of both ROM and NZ. There was no significant difference in extension modes for the three Groups. CONCLUSION: ACDFTP(Group 3) demonstrates the most effective stabilization followed by ACDFPW(Group 2), and ACDFP(Group 1). ACDFP provides sufficient strength in most loading modes, ACDFP can provide an effective stabilization for bilateral cervical facet dislocation with a brace.

Cortical Margining Capabilities of Fins Associated with Ventral Cervical Spine Instrumentation

Fins incorporated into the design of a dynamic cervical spine implant have been employed to enhance axial load- bearing ability, yet their true biomechanical advantages, if any, have not been defined. Therefore, the goal of this study was to assess the biomechanical and axial load-bearing contributions of the fin components of the DOC ventral cervical stabilization system. Eighteen fresh cadaveric thoracic vertebrae (T1-T3) were obtained. Three test conditions were devised and studied: Condition A (DOC implants with fins were placed against the superior endplate and bone screws were not inserted) ; Condition B (DOC implant without fins was placed and bone screws were inserted) ; and Condition C (DOC implant with fins were placed against the superior endplate and bone screws were inserted). Specimens were tested by applying a pure axial compressive load to the superior platform of the DOC construct, and load-displacement data were collected. Condition C specimens had the greatest stiffness (459 +/- 80N/mm) and yield load (526 +/- 168N). Condition A specimens were the least stiff (266 +/- 53N/mm), and had the smallest yield loads (180 +/- 54N). The yield load of condition A plus condition B was approximately equal to that of condition C, with condition A contributing about one-third and condition B contributing two-thirds of the overall load-bearing capacity. Although the screws alone contributed to a substantial portion of axial load-bearing ability, the addition of the fins further increased load-bearing capabilities.

A Case of Pharyngoesophageal Diverticulum (Zenker's Diverticulum) Following Anterior Cervical Spine Screw or Plate Fixation / 대한소화기내시경학회지

As a complication following anterior cervical spine screw or plate fixation, a pharyngoesophageal diverticulum (Zenker's diverticulum) is rare in comparison with iatrogenic esophageal perforation or tracheo-esophageal fistula. Esophageal perforation or fistula usually develop abrupt and severe symptoms such as fever, dyspnea, coughing or swelling on the cervical area. However. there is no definite symptoms except mild and chronic dysphagia in case of pharyngoesophageal diverticulum. Therefore, it is very likely that the diagnosis will be delayed and serious complication will be occurred. We report a case of 58-year-old spinal cord injured man with a Zenker's diverticulum following anterior cervical plate fixation.

Instrument Failure in Anterior Cervical Plate Fixation

OBJECTIVE: Anterior cervical fusion is widely used with many kinds of plate systems. The purpose of this study is to evaluate the rate and influencing factor of instrument failure. METHODS: The authors reviewed 101 consecutive patients who underwent anterior interbody fusion used Caspar, PCB(Cervical Plate Cage System), Orion and Atlantis plate system during the period of January 1991 to December 2000. The cases of trauma were 49, tumor 2 and degenerative disorder 50. The average length of follow up was 12.2 months. RESULTS: There were 10 cases of instrument related complications and 18 cases of non-instrument related complications. Among 10 cases of instrument related complication, eight patients showed screw loosening and two patients showed bone graft displacement. The nine cases of hardware failure occurred within 3 months. The rate of instrument failure was higher in trauma, unlocking plate and multi-level than non-trauma, locking plate and one-level. There were no injuries to tracheoesophageal or neurovascular structures as a results of instrument failure. CONCLUSION: We conclude that anterior cervical plating can be carried out with acceptable complication rate. The incidence of prominent instrument failure that endangers tracheoesophageal structures is minimal.

Outcome Analysis of the Patients with and without Anterior Plating in Multi-Level Degenerative Cervical Diseases

OBJECTIVES: The rates of pseudarthrosis for two- and three level fusion have been reported to be 17-63 and 50% without anterior cervical plating. The purpose of this study is to assess the effects of anterior cervical plating in the treatment of multilevel degenerative cervical disease such mostly the additional risks associated with hardware implants and its benefits, fusion rate and radiographic results, and clinical outcomes. METHODS: Forty-seven patients who underwent operations between 1993 and 1997 were retrospectively reviewed. The technique for operation was same for both groups(Smith Robinson with autologous iliac bone graft). Group I consisted of 35 consecutive patients treated with anterior cervical decompression and fusion with anterior cervical plate fixation. Group II consisted of 12 consecutive patients treated without plate fixation. We compared clinical outcomes by Prolo score, radiographic results in the rate of fusion, cervical lordosis by Gore angle, disc height by Farfan method, and surgical complications between two groups. RESULTS: The favorable clinical outcomes(excellent and good) by Prolo score were observed with the use of anterior cervical plate fixation(89% vs 75%). The successful fusion rate of multilevel cervical fusion was as seen with anterior cervical plate fixation(97% vs 75%). The overall graft complication rate in multilevel fusions was decreased, with anterior cervical plate fixation, and the hardware related complications were relatively minimal without serious consequences. CONCLUSION: Anterior cervical plate fixation in the treatment of multilevel cervical disorders is an effective stabilizing method which provides increased bony fusion rate, decreased graft complications, maintained cervical lordosis, early mobilization of the these patients without serious hardware related complications.

Anterior Cervical Fusion with or without Plates after Discectomy in Cervical Spondylosis

The purpose of this study was to evaluate the role of anterior cervical plate after discectomy and autologous iliac bone graft in the treatment of cervical spondylosis. One hundred and seven cervical spondylotic patients from Jan. 1995 to Mar. 1998 were separated into two groups: Group 1. consisted of 58 patients treated with anterior discectomy, bone fusion, and anterior cervical plate fixations(54 cases of Caspar nonlocking plate and 4 cases of Orion locking plate system), Group 2. consisted of 49 patients treated with anterior discectomy and bone fusion. The mean follow-up duration was 26.5 months(from 6 to 45 months). The overall fusion rate did not showed any difference between the two groups, but in multi-level patients, graft materials related complications(extrusion or collapse of graft) were significantly high in group 2.(p<0.01). Group 1. patients ambulated on POD 1 with Philadelphia collar. The average admission period was 8.4 days following operation. Group 2. patients ambulated on POD 5-7 with Philadelphia collar. The average admission period was 11.9 days after surgery. In conclusion, bony fusion was successfully achieved in both groups and graft materials related complication rate showed no difference in the single level, but was significantly low in group 1 in the multilevel.

Anterior Cervical Fusion and Plate Stabilization in Patients with Lower Cervical Lesions

Anterior cervical discectomy and fusion is an efficacious procedure used to treat a variety of cervical spinal disorders, including spondylosis, myelopathy, herniated discs, trauma, and degenerative disc diseases. Refinements in instrumentation for the cervical spine have led to an increase in experience with these devices during the past decade. The need for postoperative immobilization, required to stabilize the patient while the fusion mass heals, is decreased or negated by internal fixation. The authors analyzed the results in 30 patients(22 traumatic; 8 non-traumatic) with lower cervical lesions, who underwent anterior interbody fixation with cervical plates between April, 1994 and June, 1996. We used either a unicortical(Orion TM) or bicortical screw system(Top TM): these two types of plates had no specific differences, but the Orion TM was easier and safer to operate. Although postoperative stability was successfully attained in all patients, two screw-related complications, which were fully resolved without causing any specific problems, were detected during the postoperative follow-up period. In nontraumatic lesions, we measured pre-and postoperative interbody heights at ten levels; postoperative interbody height was well preserved for one year. In conclusion, internal fixation may provide added security to the nervous system before bony fusion occurs, may lessen the number of levels requiring fusion, may increase the probability of successful fusion, and is conducive to early patient mobilization.

Long-term Follow-up Results of Anterior Cervical Interbody Fusion with and without Cervical Plate

Eighty-four patients whose cervical lesions not associated with any trauma or tumor were operated for anterior cervical interbody fusion. The patients were separated into two groups, one group operated with a cervical plate and the other group, without the cervical plate. The mean follow-up duration in anterior cervical interbody fusion with cervical plate cases was 16 months(from 6 months to 30 months), without cervical plate 35 months(from 6 months to 84 months). Retrospective analysis of the two groups were done in order to compare the incidence of postoperative complications, clinical outcome, and radiological changes. The most notable postoperative complications of the group operated without the cervical plate were migration of the bone graft(3.3%) and angulation(3.3%), whereas of the group operated with the cervical plate were screw loosening(4.2%) and infection of the operative wound(4.2%). Comparative analysis of the postoperative clinical outcome and changes in radiological measurement of the intervertebral heights and angles showed no statistically significant difference between the two groups. The results of this study suggest that whether or not the cervical plate should be used for anterior cervical interbody fusions requires a decision made carefully and meticulously by the operator, so that the possibility of any postoperative complications can be minimized.

Clinical Analysis of Anterior Approach with the Several Types of Cervical Plate for the Lower Cervical Lesions

The surgical approach to the lower cervical lesions, especially in traumatic injuries, has been controversial. Some authors advocated posterior fusion for such lesions, while others disagreed and reported good operative results with anterior approach using several types of cervical plates. We analysed 28 patients with lower cervical spine traumatic as well as pathological lesions who underwent 32 anterior surgical interventions with cervical plates during the period of August, 1991 and December, 1993. A successful postoperative vertebral stability was obtained in 5 patients(89.3%) and in 19 patients(87.5%) who had predominent posterior ligamentous injuries. Serious complications such as esophageal perforation and postoperative angulation were seen in 5 patients(17.3%) that were related to the process of reduction. With our clinical experiences, we support anterior fusion with cervical plates particularly for lower cervical lesions even though posterior fusion has ben preferred for traumatic posterior ligamentous complex injuries.

Posterior Cervical Plate Fixation in Cervical Injuries

Posterior stabilization of unstable cervical spine injury using metal plate and screw has been commonly used in Europe but very rarely in Korea where it has been usually achieved with wires supplemented by bone graft. We have experienced 11 patients of unstable lower cervical spine injuries which were stabilized with posterior cervical plate without bone graft. One patient was total quadriplegia and two patients showed minor motor and sensory changes and the others were neurologically intact. Operations were performed within 10 days after trauma(average 4.9 days) except 2 cases of late instability. Most of the patients could ambulate the day after operation with a Philadelphia collar which was kept for 3 months. We achieved good postoperative alignment of injured cervical spine and tolerable neck motion limitation and we experienced no surgical complication. So we suggest that posterior cervical plate fixation technique is a good method of cervical stabilization for lower cervical spine injury, especially when posterior compartment injury is predominant.

Anterior Interbody Fusion Combined with Anterior Cervical Plate Fixation in Cervical Spine Injury

The anterior interbody fusion combined with internal metal plate fixation was performed from January, 1988 in seven patients with unstable mid and lower cervical spine. The insertion of the metal plate was simple and maintained the block bone graft in satisfactory position. We concluded from this early follow-up that, this alternative method of internal fixation of cervical spine allowed not only effective stabilization for the unstable spine but also early mobilization and short hospital stay.

Discussion on the anterior locking cervical plate systems / 重庆医科大学学报

Objective:To observe the result and to study the complications and prevention methods for the different anterior locking cervical plate systems.Methods:150 patients with the cervical fracture-dislocations,spondylotic myelopathy,tuberclusis and tumors of the cervical spine were treated using CSLP?ORION and CODMAN anterior locking cervical plate systems.Results:All the patients were followed up for 3-6 months. The symptom of nervous system recovered,and the bone grafting was fused completely.The complications related to the anterior cervical plate occurred including protrusion of the fixation screws into disc pace,defluxion of the plate,migration of the screws and plate.Most of the complications were caused by insufficient exposure and improperly technological performance.Conclusion:Anterior locking cervical plate systems can provide reliable stability for the fixation segments and it is useful for fusion of the grafting bone,it is important to be familiar with anatomical knowledge of the cervical vertebrae,sufficient exposure of the lesion,correct plate selection and proper technical principles of the different anterior locking cervical plate systems play an important role in avoiding the complications.