Caspar Plate Research Articles

Clinical outcome following anterior cervical discectomy and fusion with and without anterior cervical plating for the treatment of cervical disc herniation-a 25-year follow-up study.

Extreme long-term clinical outcome studies following anterior cervical discectomy and fusion (ACDF) with an autologous iliac crest with and without Caspar plating (ACDF+CP) for the treatment of radiculopathy caused by cervical disc herniation (CDH) are extremely rare. Hospital records of patients who underwent ACDF or ACDF+CP for the treatment of CDH at least 17years ago were reviewed. Information about diagnosis, surgery, pre- and postoperative clinical process, and repeated procedure was analyzed. At final follow-up, patients were reviewed with a standardized questionnaire including the current neurological status, Neck Disability Index (NDI), Odom's criteria, a modified EQ-5D, and limitations in quality of life. One hundred twenty-two patients with a mean follow-up of 25years were evaluated. ACDF was performed in 80 and ACDF+CP in 42 patients, respectively. At final follow-up, 81.1% of patients were free of radicular pain and had no repeated procedure. According to Odom's criteria, 86.1% of good to excellent functional recovery was noted. The mean NDI and EQ-5D was 14% and 5 points, respectively. There was no significant difference in the assessed clinical outcome parameters between patients treated with ACDF and ACDF+CP. The rate for repeated procedure due to degenerative cervical disorders was 10.7 and 7.4% due to symptomatic adjacent segment disease with 25years. ACDF and ACDF+CP achieved a high rate radicular pain relief (89.3%) and clinical success (86.1%) for the treatment of CDH within a 25years follow-up. No statistical difference concerning clinical outcome and rate of repeated procedure was detected.

Smith-Robinson procedure with and without Caspar plating as a treatment for cervical spondylotic myelopathy: A 26-year follow-up of 23 patients

The purpose of this study was to assess long-term follow-up data after anterior cervical decompression and fusion (ACDF) with and without Caspar plating (ACDF+PS) for the treatment of cervical spondylotic myelopathy (CSM) with special focus on functional outcome, pain, and repeat surgery for adjacent segment disease (ASD). Hospital records of 45 patients who were affected by CSM and underwent ACDF or ACDF+PS at least 17years ago were reviewed. Information about diagnosis, surgical report, pre- and postoperative clinical process, and complications was analyzed. Clinical outcome was assessed using a standardized questionnaire including the Neck Disability Index (NDI), modified JOA-score, Odom's criteria, limitations in quality of life, and questions about the current neurological status and pain. Twenty-three patients with a mean follow-up of 26years were evaluated. ACDF was performed in nine and ACDF+PS in 14 patients, respectively. At follow-up 78.3% of patients were free of pain, 91.3% had no motor deficit, 73.9% had no sensory deficit, and 60.7% had no gait disturbance. The current mean NDI is 14% (range 2-44%), the mean modified JOA-score was 17.2 (range 15-18). According to Odom's criteria 78.3% of patients had clinical success. In four patients repeat surgery was indicated due to pseudarthrosis or symptomatic ASD (17.4%). ACDF and ACDF+PS yield significant decrease in neck pain, a significant increase in sensorimotor function and a high rate of clinical success. Patients with preoperative gait disturbance completely recovered in about 60% of cases. Overall prevalence for ASD was 17.4% after 25years.

311 Smith-Robinson Procedure With an Autologous Iliac Crest Bone Graft With and Without Caspar Plating as a Treatment for Soft Cervical Disc Herniation

311 Smith-Robinson Procedure With an Autologous Iliac Crest Bone Graft With and Without Caspar Plating as a Treatment for Soft Cervical Disc Herniation

Smith–Robinson Procedure with an Autologous Iliac Crest Graft and Caspar Plating: Report of 65 Patients with an Average Follow-up of 22 Years

Anterior cervical discectomy and fusion with plate stabilization (ACDF+PS) is an accepted surgical procedure. We sought to evaluate the long-term clinical results of ACDF+PS with a special focus on pain, functional outcome, and adjacent segment disease. Retrospectively, 139 patients who underwent ACDF+PS were reviewed with a standardized questionnaire including the current neurologic status, Neck Disability Index, EuroQuol-5 Dimension, Patient Satisfaction Index, Hospital Anxiety and Depression Scale, the Odom criteria, complications at the iliac crest donor side, and limitations in quality of life. Mean follow-up time was 22 years (range: 17-34 years). Sixty five (46.8%) patients were evaluated by completed questionnaires, and 74 (53.2%) did not participate. Forty-six patients attended a physical examination. ACDF+PS were performed at 1 level in 28 patients, at 2 levels in 29 patients, and at 3 levels in 8 patients. Fifty (83.3%) of the patients with preoperative pain remained free of pain and did not require another procedure as the result of degenerative cervical disease. The mean NDI was 14%; according to the Odom criteria 86.2% of patients reported good-to-excellent functional recovery. A total of 100% of patients were satisfied or very satisfied with their outcome and would decide to undergo ACDF+PS again. Two developed adjacent segment disease and needed a second procedure. ACDF+PS resulted in a significant increase in function, pain relief, and to a high degree of patient satisfaction. The rate for symptomatic adjacent segment disease was 4.5% after 20 years' follow-up.

Cespace: sistema de fusión intersomática cervical: Estudio preliminar en 104 casos (120 implantes)

Cespace is a cervical implant designed to obtain intervertebral fusion without bone grafting. The implant is built in titanium and coated with plasmapore (a sort of pure titanium powder). Bone growing through titanium microstructure is induced by the plasmapore, and fusion is progressively obtained once this boneinduction is completed. From January 2002 to December 2008 we operated upon 104 patients employing this implant at one or two cervical spine levels. The more frequent condition was radiculopathy caused by disc herniation or spondilosis (N= 85; 81.7%), followed by mielopathy (N=13; 12.5%). Six cases (5.7%) corresponded to cervical fractures or dislocations. In these latter ones Cespace was implanted as a method of spinal stabilization combined with Caspar plates, avoiding bone grafting. The total number of Cespace implants placed was 120. Clinical results were good in 85.5% of patients. Primary stability was obtained in all cases. Secondary stability (fusion) was evident after 1 to 2 years in all cases, confirming the bone-induction capability of plasmapore without bone grafting. No specific implant complications (pseudoartroses, settling, instability, etc) were registered. We conclude that radical microdiscectomy and Cespace box implant constitutes a good procedure for the treatment of cervical radiculopathy or mielopathy caused by disc herniation or spondylosis, avoiding bone grafting and providing high rates of vertebral fusion. In some cervical fractures associated to instability, Cespace can be used as a reliable substitute of intervertebral bone grafting in combination with anterior plate fixation.

Ｐｌａｔｅを使用した頚椎前方固定術の合併症の検討

(Objective) Complications that arise follwing anterior fusion of the cervical spine using a plate are an important clinical issue. We therefore monitored patients who underwent anterior fusion at our hospital and investigated complications associated with this surgery. (Subjects) Subjects were 126 patients (86 male, 40 female ; age range 17-78 years, mean age 52.5) who underwent anterior fusion of the cervical spine using a plate between November 1993 and June 2003. The duration of postoperative follow-up ranged from 0.5 to 80 months (mean : 15.8 months). The breakdown of the 126 patients was as follws : disk herniation (n=60), spondylotic myelopathy (n=27), dislocation fracture (n=18), vertebral body fracture (n=6), spondylotic radiculopathy (n=5), neoplasm (n=2), metastatic neoplasm (n=2), and others (n=6). The CSLP (AO) plate was used in 121 patients, PEAK plate in three patients, and Caspar plate in two patients. (Results) The following six complications were documented : postoperative screw damage (n=3), plate damage (n=2), discomfort in swallowing (n=2) and loosened screw (n=1). However, no plate-related complications were observed during surgery.

Biomechanical comparision of the stable efficacy of two anterior plating systems

Objective. To compare the immediate stable efficacy and load sharing effect of two types of anterior cervical screw-plating instrumentations: the Morscher Synthes titanium locking screw-plate system and the Caspar trapezoidal screw-plate system. Design. Fresh porcine cervical spines with intact, two surgery unstable models, and then reconstructed with or without screw-plating instruments were compared in three physiological loading conditions. Background. Two markedly instrumentation systems––Morscher Synthes titanium cervical locking screw-plate and Caspar trapezoidal screw-plate systems are commonly used in management of complex cervical spine disorders. Although the biomechanical study showed that the lower cost Caspar system performed superior in extension before and after plate fatigue, the clinic evaluations of two systems were contradictory. So (1) does the titanium cervical locking plate system pay for its higher cost? and (2) what is the load sharing character of strut graft in one level corpectomy? Methods. Eight fresh ligamentous porcine cervical spines from C3 to C7 were undergone axial compression, rotation and sagittal flexion tests. The biomechanical experiment was sequentially repeated for the intact, C5-6 discectomy, C5 corpectomy, and then stabilized by either type of plate fixation devices with or without polymethylmethacrylate bone cement grafting. Strains measured by an extensometer across the operated motion segment were used as the index of stability. Results. Analysis of the strain data showed both types of anterior fixation plate systems provided adequate-restored stability for the spinal column only aided with polymethylmethacrylate construction. Statistically, there was no significant difference in biomechanical evaluation for the stability effect between much cost Morscher Synthes plate and Caspar plate system ( p<0.005). The spinal disc bore as much as 75% of axial loading. While the strut graft functioned as the disc substitute and spacer, it bore more than 90% of axial loading. In high degree of flexion, the transmitted compressive load was shifted anteriorly to the screw-plate. This might unload the polymethylmethacrylate graft and resulted in the strut graft in tensile fatigue failure. Conclusions. Statistically both systems showed similar stable efficacy, however, the Morscher Synthes cervical locking plate system might provide better stable effect in higher degrees of flexion motion. The strut graft played as the major load-bearing role in axial compression and sagittal flexion, while in axial rotation, the applied torque was mainly resisted by facet joint and screw-plate system complex. Relevance The minor discrepancy of two plating systems may be due to the nature of plate geometry and design but not the material properties. Combination of bone graft and either plating systems provides adequate fusion stability under physiological loadings. The high degree flexion may cause the posterior portion of polymethylmethacrylate graft in tensile fracture and then result in polymethylmethacrylate failure in clinic observation.

Conservative and operative treatment in cervical burst fractures

The aim of this study is to compare the results of non-operative and anterior operative treatment of cervical burst and flexion teardrop fractures. Sixty-nine consecutive patients treated during 1980 to 1995 were reviewed retrospectively. Thirty-four of them had been treated with skull traction or halo-vest and 35 with anterior decompression, bone grafting and fixation by an anterior Caspar plate. Neurological functioning on admission and at the end of the follow-up was assessed by using Frankel's classification. Kyphosis and spinal canal encroachment by retropulsed fragments were measured radiographically. Operatively treated patients recovered more often with at least one Frankel grade (P = 0.027) and presented less narrowing of the spinal canal (P = 0.0006) and kyphotic deformity (P = 0.00003) at the end of the followup. In comparison with the conservative methods, the operative Caspar technique provided superior decompression and fixation as well as promoted the healing of cord injuries caused by burst and flexion teardrop fractures.

Fusion and instrumentation at C1-3 via the high anterior cervical approach.

The high anterior cervical, retropharyngeal approach to the anterior foramen magnum and upper cervical spine is a favorable alternative to the transoral and posterolateral approaches, which both cause instability of the craniovertebral junction. Previously, such instability was corrected via an occipitocervical fusion during a separate surgical procedure. Seven patients requiring C-2 corpectomy (foramen magnum meningioma [two patients], critical stenosis secondary to rheumatoid arthritis [two patients], C-2 fracture [two patients], and stenosis secondary to Rickets [one patient]) are presented. All patients underwent C1-3 fusion followed by instrumentation with a Caspar plate. A solid fusion was achieved in six patients. One patient experienced erosion of the anterior arch of C-1 requiring posterior stabilization. Fusion and instrumentation at C1-3 can be performed safely and with minimal increase in surgical time. In selected patients, this may eliminate the need for an additional posterior procedure and maintain occipital-C1 mobility.

Evaluation of a new monocortical screw for anterior cervical fusion and plating by a combined biomechanical and clinical study.

The purpose of this combined study was to evaluate the stability and safety of a new monocortical screw-plate system for anterior cervical fusion and plating (ACFP) according to Caspar in comparison with classical bicortical fixation. In the biomechanical part of the study two groups, each comprising six fresh human cadaveric spines (C4-C7), matched for bone mineral density, additionally resulting in almost the same mean age, were used. Range of motion and neutral zone were analyzed in flexion-extension, rotation (left, right) and lateral bending (left, right) using pure moments of +/- 2.5 Nm for each specimen in the intact state, after discectomy at C5/6 and after discectomy at C 5/6 followed by bone grafting plus plating (Caspar plates), with either monocortical or bicortical screws. For all three motion planes, no significant difference could be found between the new monocortical and the bicortical fixation techniques. The clinical part of the study was performed as a prospective study on 30 patients suffering from symptomatic degenerative cervical disc disease in one segment. At the latest follow-up, no hardware- or graft-related complications were seen in any of the patients. Following these findings monocortical screw fixation can be recommended for the majority of anterior cervical fusion and plating procedures in degenerative disease, making the procedure quicker, easier, and safer. Bicortical screw fixation still has specific indications for multilevel stabilization, poor bone quality (osteoporosis, rheumatoid disease - as bicortical oversized rescue screw), unstable spines (trauma, tumour) and in particular for the realignment of kyphotic deformities (restoration of the normal lordotic curve). Due to the design of the study the results apply only to surgical treatment of monosegmental degenerative disc disease at the time.

Anterior Cervical Fusion Using Caspar Plating: Analysis of Results and Review of the Literature

Background Ninety-seven patients underwent anterior cervical fusions after discectomy and/or corpectomy. Fibular allograft was used in 13 cases and iliac crest was used in the remaining 84 patients. Methods Lateral cervical spine X-rays were reviewed for evaluation of fusion and instrumentation failures. Results Solid fusion was achieved in all but two patients (97.91%). Nineteen patients developed instrumentation related failures. Seven patients developed fracture of one screw each (one superior and six inferior). Ten patients developed screw back out (inferior screw) and in one patient the superior screws were found to be 2 mm posterior to the posterior cortex but did not cause any neurological deficits. Seven of these patients underwent revision surgery. No complications related to the instrumentation were encountered in the last 34 cases. There were no infections in this series. Five patients developed temporary dysphagia. Two developed temporary deltoid weakness and three patients developed transient recurrent laryngeal nerve palsy. One developed acute airway obstruction but the patient had a pre-existing epiglottic anomaly and sleep apnea disorder. Conclusions In selected cases, the Caspar plating system affords an effective means of improving the fusion rate (97.91%) with acceptable instrumentation-related morbidity that improves with experience, (10.7% in the first 38 cases and 1.69% in the last 59 with an overall rate of 7.2%). Temporary neurological deficits seen in this series were probably not related to the Caspar plating procedure itself. Intraoperative fluoroscopic films can be misleading. Therefore regular lateral cervical spine X-rays postplating in the operating room prior to closure are recommended. Lower screws backed out in all failures and this was circumvented by using the bigger (rescue) screws at the inferior end of long constructs.

Primary reconstruction for spinal infections

Primary reconstruction using bone grafts and instrumentation for spinal infections remains controversial. Between 1991 and 1993, 27 infections of the spinal column were treated at the Department of Neurosurgery of the University of Florida. Of the 27 cases 20 (six cervical, eight thoracic, and six lumbar spine) required surgical debridement and spinal reconstruction to maximize eradication of the infection and maintenance of spinal alignment. All of the cervical and lumbar cases were caused by bacterial infections, and two of eight thoracic cases were caused by tuberculous infections. Spinal arthrodesis was performed in all cases: interbody grafts were used in 18 procedures and posterolateral onlay grafts in 14. Interbody grafts were autologous in 10 cases (six rib and four iliac crest) and homoplastic in eight (six fibular and two humerus). All of the posterolateral onlay grafts were autologous (three rib and 11 iliac crest). Spinal instrumentation was used in 15 cases: four with Caspar plates and 11 with posterior segmental fixation (five hook/rod constructs and six screw/rod constructs). Seventeen of 20 patients achieved improved clinical status postoperatively and 18 of 20 showed radiographic evidence of bone fusion. Antibiotic drugs were administered parenterally for an average of 6 weeks followed by a 3-month course of oral antibiotic medications. Tuberculous infections were treated for 1 year with antibiotic therapy. The average follow-up period was 37 months from surgery and 31 months after completion of treatment with antibiotic drugs. The authors conclude that primary arthrodesis and instrumentation can be performed in acute spinal infections; however, successful management depends on aggressive debridement of infectious foci and prolonged treatment with parenteral antibiotic drugs.

Radiographic and clinical follow-up review of Caspar plates in 49 patients.

Although they are excellent clinical tools, Caspar anterior cervical plates have not been studied closely with regard to their mechanisms of failure. As more extensive operations are contemplated on older, sicker patients, it is imperative to know when a plating system might be prone to failure and what the mechanism of that failure might be. Therefore, the authors reviewed 49 patients undergoing Caspar plate placement in whom sufficient radiographs were obtained to determine if the fate of the hardware was related to the patient's age, type of operation, and the length of construct. Eleven of 49 patients suffered hardware failure, defined as any amount of screw backout or breakage, plate pullout, or pseudarthrosis. Four patients underwent hardware removal; one underwent posterior fusion for pseudarthrosis. Only two required treatment in a halo brace. There was an eventual fusion rate of 100%, including one fibrous union, and one of the patients who underwent repeat surgery was lost to follow-up review. No graft extrusions or new neurological deficits were incurred as a result of hardware failure. Plate length predicted plate failure in a statistically significant manner. Increasing age and reoperation correlated with plate failure but were not statistically significant in this small number of patients. Telescoping of the bone graft and vertebral bodies, with concomitant migration of the plate and slippage of the screws, was common. However, telescoping was more profound in the group in which the plates failed. The authors conclude that Caspar plate failures are more likely to occur in the elderly and in patients who need longer constructs. Bone fusion can be expected even when the hardware loosens.

Radiographic followup of Caspar plate hardware of the cervical spine: Is the AP view necessary?

Radiographic followup of Caspar plate hardware of the cervical spine: Is the AP view necessary?

Assessment of Unicortical and Bicortical Fixation in a Quasistatic Cadaveric Model

The stabilizing potential of the Caspar Trapezial Osteosynthetic Plate was studied using unicortical and bicortical screw placement in cadaveric cervical spines. To determine if Caspar plates secured with unicortical screws provide the same degree of stability as those anchored with unlocked bicortical screws. Previous work has demonstrated that bicortical cervical vertebral screws are superior to unicortical screws in terms of pullout strength and decreased wobble. However, these two methods of plate fixation have not been directly compared in a clinically relevant cadaveric model. The immediate and post-fatigue stabilizing potential of Caspar plates secured with unicortical or bicortical screws was assessed using a model of complete segmental instability. Unicortical screw placement resulted in inadequate stabilization in half of the cervical specimens. Our results suggest that, for the Caspar screw, bicortical fixation provides greater flexion-extension stability.

Magnetic Resonance Imaging of Titanium Anterior Cervical Spine Plating Systems

Magnetic resonance imaging (MRI) of titanium anterior cervical plating systems and their effect on postoperative images were evaluated ex vivo and in vivo. The Synthes and Caspar plating systems were examined by 0.5- or 1.5-T MRI scanners. A phantom study of these implants showed that in spin-echo modes, the plates and screws were seen as areas of signal loss accompanying a marginal hyperintense band, which was more obvious in higher tesla magnetic fields. Distortion of the magnetic field was more prominent in T2-weighted images. In gradient echo mode, the plate and screws were seen as areas of signal loss larger than the size of the metal because of the magnetic susceptibility effect. Postoperative MRI produced images of the implants similar to those observed ex vivo. The Synthes plating system did not interfere with the evaluation of the spinal cord, and the Caspar screw (which penetrated the posterior cortex of the vertebral body) caused a small artifact to be present at the anterior aspect of the spinal cord. In addition to being able to provide fixation of the cervical spine, titanium anterior cervical plates allow superior MRI of the postoperative spine.

Anterior cervical fixation with the titanium locking screw-plate: A preliminary report

Anterior fixation of cervical spine with screw-plates is gaining in popularity in the management of anterior cervical spine instability. We report on our initial experience with anterior cervical fixation using the titanium locking screw-plate (TLSP). Twelve cases, including cervical trauma, cervical spondylosis, and ossification of the posterior longitudinal ligament (OPLL), underwent multilevel corpectomies or spondylectomies with iliac bone or hydroxylapatite grafting combined with the TLSP system. All 12 patients fused or stabilized with improvement of their neurologic symptoms at a mean follow-up period of 13 months. There were no complications relating to this plating system. Three illustrative cases are presented. Different from previous anterior cervical planting systems such as the Caspar plate, the TLSP system does not gain purchase on the posterior vertebral cortex. It thus reduces possible spinal cord injury during screw placement. The TLSP with interbody fusion may provide reliable stabilization of the cervical spine in a safe and effective manner.

Biomechanical characteristics of Caspar and synthes plates used to stabilize cervical spines before and after cyclic loading

Biomechanical characteristics of Caspar and synthes plates used to stabilize cervical spines before and after cyclic loading

Biomechanical Evaluation of Caspar Cervical Screws

Anterior cervical instrumentation is used as an adjunct to bone fusion; however, definitive biomechanical data to support some applications and techniques are lacking. In the absence of supportive experimental data, posterior cortical penetration has been recommended with the Caspar system. Previously, we compared the axial pull-out strength of Caspar screws with and without posterior cortical penetration. This study compares the stability of unicortical versus bicortical screw penetration groups under cyclical loading simulating physiological flexion-extension. Caspar screws were placed in human cadaveric vertebrae with or without posterior cortical purchase. Each screw was separately tested, simulating flexion-extension to 200 cycles. Deformation time data allowed a direct comparison of screw "wobble" with and without posterior cortical purchase. The mean deformation differences between subcortical and bicortical groups were statistically significant and increased over time within both groups. Enhanced stability was noted with bicortical purchase throughout most of the examined range, becoming more pronounced over longer periods of cyclical loading. Significant (P < 0.05) increases in deformation over time were noted for both groups, suggesting potentially significant deterioration at the screw-bone interface, despite bicortical purchase. Such deterioration with repeated flexion-extension loading may be of concern in the use of Caspar plates in the presence of multicolumn instability.

Anterior decompression, structural bone grafting, and Caspar plate stabilization for unstable cervical spine fractures and/or dislocations.

Fourteen patients who sustained acute cervical spine fractures and/or dislocations with associated posterior ligamentous disruption had anterior decompressions, structural bone grafting, and anterior Caspar plate stabilization. With an average 30-month follow-up, no patient has had loss of fixation. Despite criticism raised from biomechanical testing, the Caspar anterior plate system (Aesculape, Tuttlingen, Germany) may be added to structural bone grafting of unstable cervical fractures and/or dislocations, yielding an in vivo solid construct, which obviates the need for simultaneous posterior stabilization.