Animal Models of Orthopedic Research: A Spinal Fusion Model / 대한정형외과학회잡지

The incidence of spinal fusion surgery has increased due to an increase in the incidence of degenerative spinal disease or trauma. Moreover, the development of various kinds of implants and bone graft substitutes has also increased. The animal models of spinal fusion are useful methods in evaluating the effectiveness of the newly developed spinal implants or bone graft substitutes. The most widely used animal models of spinal fusion are posterolateral fusion model, posterior fusion model, and anterior interbody fusion model. Mice, rats, rabbits, dogs, pigs, goats, sheep, and primates are frequently used in animal models of spinal fusion. Small animals are implanted with a bone graft substitute without internal fixation; however middle- or large-sized animals are implanted with a bone graft substitute using pedicle screws or cages. Small animals are easy to handle due to their size, but have different anatomical or biomechanical reactions with the human body. Middle- or large-sized animals have characteristics like the human body, but they are difficult to handle or there is an ethical problem. The fusion status is evaluated by manual palpation, mechanical testing using Instron, and radiologic techniques such as computed tomography, micro-computed tomography or undecalcified histology. The fusion rate and duration required for successful fusion differ according to the species and anatomical site. We have identified and reviewed several typical animal models of spinal fusion.

Anterior Cervical Fusion Using a Zero-Profile Stand-Alone Cage: Radiological and Clinical Outcomes after More than 2 Years of Follow-Up

STUDY DESIGN: Retrospective analysis. OBJECTIVES: To analyze the usefulness of Zero-P® by analyzing the radiological and clinical outcomes with a minimum of 2 years of follow-up. SUMMARY OF LITERATURE REVIEW: Anterior discectomy and fusion (ACDF) using Zero-P® showed excellent results. However, there is a lack of studies focusing on long-term outcomes. MATERIALS AND METHODS: Ninety-eight patients who underwent single-level ACDF using Zero-P® with more than 2 years of follow-up were included for analysis. In the radiological analysis, we evaluated disc height, segmental lordosis, and subsidence in the preoperative, postoperative, and last follow-up periods. The Neck Disability Index (NDI), Neck Visual Analogue Scale (VAS), and Arm VAS were also evaluated for clinical assessment. Radiological bony fusion was assessed, and radiological and clinical differences according to bony fusion were evaluated. RESULTS: Intervertebral disc height had increased 2.92 mm after surgery and subsided to 2.36 mm at the final follow-up. Subsidence of the screw was 0.58 mm at final follow-up. Segmental lordosis was 3.97° at the preoperative assessment, 8.39° in the postoperative follow-up, and 5.83° in the last follow-up. The Neck VAS score was 4.47, 2.28, and 1.27, respectively. The Arm VAS score was 5.73, 3.13, and 2.18; and NDI score was 17.8, 11.7, and 7.89, respectively. There was no association between the radiological and clinical results. Radiological nonunion was found in 18 subjects. There were no significant differences in radiological and clinical parameters according to bony union. CONCLUSIONS: ACDF with Zero-P® for treatment of degenerative cervical disease showed subsidence in 55.1% and nonunion in 18% of cases. However, the radiological results were not related to the clinical results.

Prevalence And Risk Factor of Degenerative Disease of Adjacent Segment after Anterior Cervical Arthrodesis

STUDY DESIGN: A retrospective radiologic and clinical analysis of 48 patients following anterior cervical fusion. OBJECTIVES: To examine the prevalence of symptomatic adjacent segment disease after anterior cervical fusion and determine the risk factors affecting its progression. SUMMARY OF LITERATURE REVIEW: Symptomatic adjacent segment disease appears to occur at a rate of 2% to 3% per year. MATERIALS AND METHODS: Forty-eight patients, who were followed up for more than 3 years after anterior cervical arthrodesis, were enrolled in this study. A modification of the Robinson criteria was used for the clinical evaluation and the radiographic grading of Hilibrand was used for the radiology evaluation. Kaplan-Meier survival analysis was used to examine the survival rate. Age, gender, number of fusion segments, preoperative ROM, angle of lordosis, spinal canal diameter and radiologic degeneration of adjacent segments were selected as potential risk factors. The subjects were divided into two groups according to their clinical symptoms. RESULTS: Symptomatic adjacent segment disease developed in 11 of the 48 patients(22.9%). The disease free survival rates were 88.7%, 82.4% and 58.7% at 5, 10 and 15 years, respectively. A study of the risk factors showed that preoperative degenerative changes and narrow spinal canal in the adjacent segments were significant. However, there were no significant associations with age, gender, number of fusion segments, preoperative ROM and angle of lordosis. CONCLUSION: The prevalence of symptomatic adjacent segment disease after anterior cervical fusion was considerable and higher when the patients had preoperative degenerative changes and a narrow spinal canal in the adjacent segments.

Comparison of Surgical Outcomes in Thoracolumbar Fractures Operated with Posterior Constructs Having Varying Fixation Length with Selective Anterior Fusion

PURPOSE: Surgical treatment in the case of thoracolumbar burst fractures is very controversial. Posterior instrumentation is most frequently used, however, but the number of levels to be instrumented still remains a matter of debate. MATERIALS AND METHODS: A total of 94 patients who had a single burst fracture between T11 and L2 were selected and were managed using posterior instrumentation with anterior fusion when necessary. They were divided into three groups as follows; Group I (n = 28) included patients who were operated by intermediate segment fixation, Group II (n = 32) included patients operated by long segment fixation, and Group III (n = 34) included those operated by intermediate segment fixation with a pair of additional screws in the fractured vertebra. The mean follow-up period was twenty one months. The outcomes were analyzed in terms of kyphosis angle (KA), regional kyphosis angle (RA), sagittal index (SI), anterior height compression rate, Frankel classification, and Oswestry Disability Index questionnaire. RESULTS: In Groups II and III, the correction values of KA, RA, and SI were much better than in Group I. At the final follow up, the correction values of KA (6.3 and 12.1, respectively) and SI (6.2 and 12.0, respectively) were in Groups II and III found to be better in the latter. CONCLUSION: The intermediate segment fixation with an additional pair of screws at the fracture level vertebra gives results that are comparable or even better than long segment fixation and gives an advantage of preserving an extra mobile segment.

Fractures and Dislocations of the Cervicothoracic Junction

Cervicothoracic junction instability should be stabilized with the circumferential fusion. In addition, cervicothoracic junctional area should be examined carefully in acute traumatic injury not only to confirm hidden lesions but also to make the proper surgical plans. Here, three patients who underwent cervicothoracic arthrodesis at our institution are presented with a review of literature.

Changes of Adjacent Segment in Anterior Cervical Fusion / 대한척추외과학회지

STUDY DESIGN: A retrospective radiographic and medical record analysis of 36 patients. OBJECTIVES: To describe the incidence and consequence of the distribution of sagittal plane motion, across the adjacent cervical motion segment, after cervical fusion. Furthermore, to find the cause of the progression of degenerative changes in intervertebral discs adjacent to the fused segment. SUMMARY OF LITERATURE REVIEW : Anterior cervical fusion has been widely used in the treatment of degenerative cervical spine. An increased incidence of degenerative disease may exist at the levels immediately adjacent to a cervical fusion. However, the frequency of these complications is probably overestimated, and their effect on clinical outcome remains unknown. MATERIALS AND METHODS: From 1990 to 1996, 36 patients who underwent anterior cervical spine fusion for degenerative disorders were reviewed retrospectively with an average follow up of 6.9 years. Lateral views in neutral position, in flexion, and in extension of the preoperative cervical roentgenograms were analyzed in comparison with the last follow-up films in the range of motion of the neck, and in the intervertebral angular mobility and anteroposterior displacement of the vertebral bodies, and finally to quantify the incidence of the spinal instability. RESULTS: Degenerative change in adjacent intervertebral level was observed in 16 of the 36 patients (44.4%), above the fusion in 10, below the fusion in 4, and both above and below the fusion in 2 cases. In addition, degenerative change in adjacent intervertebral level was observed in 68% of cases of loss of lordosis of the fused segment, and degenerative change occurred more frequently in younger patients to a statistically significant extent. CONCLUSIONS: Loss of lordosis of the fused segment and young age are two factors promoting degenerative changes in adjacent intervertebral levels after anterior cervical fusion.

Anterior Decompression and Fusion with Instrumentation in Osteoporotic Vertebral Fracture / 대한척추외과학회지

STUDY DESIGN: A Retrospective study OBJECTIVE: To evaluate the results after an anterior decompression and fusion, with anterior instrumentation, using a Z-plate in osteoporotic vertebral fractures. SUMMARY OF LITERATURE REVIEW: Despite conservative treatment, continuous severe pain, progressive neurological impairments and deformity may need surgical treatment in osteoporotic vertebral fractures accompanied with neurological deficit. MATERIALS AND METHODS: Fourteen patients that had undergone anterior decompression and an autogenous iliac bone graft, with anterior internal fixation, between 1997 and 2001, under the diagnosis of an osteoporotic vertebral fracture, were reviewed. The chief complaints, severity of pain measured, using the Denis pain scale, fracture patterns, fracture level, changes of kyphotic angle (revised with sagittal index) and complications were analyzed. RESULTS: Symptoms subsided completely in 5 patients, one case showed no definite improvement and 8 showed improved symptoms. The fracture levels included: 1 and 2 cases at the 11th and 12th thoracic spine, and 8, 1 and 2 in the 1st, 2nd and 3rd lumbar spine, respectively. 10 patients showed wedge type fractures, three a compression type and one a biconcave type. The average kyphotic deformity decreased 49.0% (50.9% when revised with sagittal index) after surgery, but the average loss of correction angle was 28.8% (26.0% when revised with sagittal index), compared with the immediate postoperative correction angle. THE COMPLICATIONS INCLUDED: screw loosening and adjacent vertebral fractures in 3 and 4 patients, respectively. Two patients had the combined problem of screw loosening and an adjacent vertebral fracture. CONCLUSION: In anterior decompression and fusion, with instrumentation, for osteoporotic vertebral fracture treatment, the complications were primarily related, directly or indirectly, to the underlying osteoporosis. Complete neurological recovery occurred 9 of the 11 patients, but residual pain was common.

Anterior Cervical Decompression and Fusion for the Treatment of Cervical Spondylotic Myelopathy / 대한정형외과학회잡지

PURPOSE: This study was designed to evaluate the suitability of anterior cervical decompression and fusion in the surgical treatment of cervical spondylotic myelopathy, and to analyze the factors influencing outcome. MATERIALS AND METHODS: Twenty-six patients were reviewed with at least one year follow-up. Preoperative duration and severity of neurologic symptoms, Pavlov ratio and the anterior-posterior compression ratio of the spinal cord were assessed to analyze the prognostic factors affecting the treatment results. The Nurick and JOA scoring system was used to classify the severity of disability associated with the myelopathy before the operation and at the latest follow-up examination. RESULTS: Though the duration of symptoms did not, the severity of pain did affect the prognosis (r=-0.500, p=0.009). The Pavlov ratio (r=-0.394, p=0.046) and the anterior-posterior compression ratio of the spinal cord were closely related to the preoperative and postoperative severity of myelopathy (r=-0.511, p=0.008). The average grade according to the Nurick system improved from 2.19 to 0.93, and the JOA score from 12.4 to 15.9. CONCLUSION: Anterior cervical decompression and fusion appears to be a reliable procedure in terms of neurological recovery, functional improvement, and pain relief in patients with cervical spondylotic myelopathy.

Results of Surgical Treatment of Spinal Tuberculosis: A Comparison between Anterior Fusion and Combined Fusion / 대한정형외과학회잡지

PURPOSE: This study was undertaken to compare anterior fusion surgery with combined fusion surgery and to evaluate the efficacy of a combined fusion procedure in the surgical treatment of spinal tuberculosis. MATERIALS AND METHODS: From March 1990 to March 1998 thirty-four patients who had with spinal tuberculosis were divided into two groups depending on the surgical treatment methods that were to be used; one group consisted of twenty-two patients who were treated by an anterior fusion surgery, and the other group consisted of twelve patients who were treated by an combined fusion surgery. There were twelve males and twenty-two females who had a mean age of 45.6 year old in the study. The mean follow-up period was four years and six months. The clinical and radiological results that were obtained were evaluated. RESULTS: In anterior fusion group, the mean loss of the corrected kyphotic angle was 6.9 degrees and an excellent or good result was shown in nineteen patients (86.4%). In the combined fusion group, the mean loss in the corrected kyphotic angle was 5.6 degrees and an excellent or good result was shown in ten patients (83.3%). There was no significant statistical difference between the two groups. CONCLUSION: We conclude that an anterior radical excision of the involved body and an anterior fusion was the appropriate method for surgical treatment of spinal tuberculosis, and combined fusion should be carefully considered.

Anterior Discectomy and Fusion With or Without Plate Fixation for One Level Cervical Disc Herniation / 대한척추외과학회지

STUDY DESIGN: A retrospective study was performed in patients with one level cervical disc herniation who had undergone anterior discectomy and fusion with or without plate fixation. OBJECTIVES: This study was performed in order to analysis the result of anterior discectomy and fusion, and to assess the benefits of the supplemental anterior cervical plate in the treatment of one level cervical disc herniation. MATERIALS AND METHODS: 35 surgically treated patients for one level disc herniation were reviewed. The Smith Robinson with autologous iliac crest bone graft was performed in both groups. Group A consisted of 14 patients who had supplemental anterior cervical fixation performed. Group B consisted of 21 patients treated without plate fixation. Radiologic parameters included the bone union and changes of intervertebral space. Clinical results were classified using the criteria of Robinson. RESULTS: In radiologic analysis, decreases in intervertebral space were common in group B, especially in older than 61 years old age group, and the bone union time was same in both groups. The overall clinical success rate was 86% in group A and 90% in group B. This difference between group A and group B is not significant. CONCLUSIONS: When selectively used in osteoporotic patient, supplemental anterior cervical plate fixation allows an early return to activities of daily living for patients and prevent deformities in graft bone. However, further studies are needed to confirm this result. Although many advantages of anterior plate stabilization have been previously reported, the plate osteosynthesis after one level fusion for radiculopathy was not thought to be a major advantage.

Experiences with anterior spinal fusion: a preliminary report

A review is made of the history of the treatment of Potts disease. A radical treatment of extirpation of the disease and anterior fusion has been briefly described. Observations and early results of extirpation and anterior fusion in 14 cases are reported. (Summary)

Anterior Cervical Fusion with Cervical Spine Locking Plate / 대한정형외과학회잡지

Anterior plate fixation of the cervical spine provides good primary stability to allow early mobilization without significant external support. Despite the obvious advantages of anterior cervical fixation, neurological injury resulting from the direct trauma of a drill bit or screw are possibile with this technique. In addition, screw loosening leading to dyphagia has been reported. The cervical spine locking plate (CSLP) system maintains the mechanical advantages of internal fixation and eliminate the neurological risks of perforating the posterior cortex. The purpose of this study is to review our experience with this device, to critically assess its ability to stabilize the cervical spine, and to assess for complications associated with this device. The authors reviewed 28 consecutive patients in whom the CSLP system was applied between April 1994 to April 1995. Average age was 44 years ranged from nineteen to seventy-two. Patients with trauma were eight and degenerative diseases were twenty. Eighteen screws were inserted in C3 bodies, twenty-four in C4, forty-one in C5, thirty-six in C6, twenty-four in C7, two in Tl and nine on grafted bone. With a mean follow-up of 15 months, 27 of 28 patients went on to fusion. Mean time to fusion was three months (range 2-5). Fusion status of one patient was considered as uncertain. Three patients had screws placed in the disc rather than in bone. One patient suffered deep wound infection, which developed to tracheoesophagial fistula. No patient showed neurological injury as a result of this device.

Results of Cervical Interbody Fusion Using the Anterior Plate System

In order to evaluate long-term effects of the anterior cervical plating system, we report the results of 59 patients who were treated with anterior decompression, autogenous iliac bone graft, and anterior cervical plate. Operations were performed on 59 patients for a variety of reasons; 40 for fracture and/or dislocation, 7 for degenerative spondylosis, 4 for ossification of posterior longitudinal ligament, 5 for pyogenic or tuberculous spondylitis, and 3 for metastatic tumor. Our study consisted of 41 male and 18 female patents whose ages ranged from 14 to 76 years. Immediate fixation was obtained in 56 cases(95%). Satisfactory fusion was obtained in ll but five cases of which the result could not be judged due to death of the patients(3 cases of metastatic disease) and removal of the instrument(2 cases of fracture). Specific complications included 5 cases of screw loosening, 2 cases of screw fracture, 2 cases of dysphagia, and 1 case of esophageal fistula. The anterior plate system is thought to provide a valuable means of treating cervical instabilities.

A Case of Recurrence of Spinal Tuberculosis Treatment with Posterior Approach and Followed by Successful Anterior Fusion on the Lumbosacral Spine

In the treatment of spine tuberculosis, anterior spinal fusion has been a widely accepted procedure since Hodgson and Stock in 1956 bacause of its many advantages. Posterior approch is a simplier & safer procedure. However the destructed vertebral body can not be removes completely by this procedure. A 50 years old female patient was admitted with lumbosacral tuberculosis showing massive destruction of the L5 & S1 vertebral body and abscess formation. We initially performed a curettage and debridement by the posterior approach, combined with chemotheraphy. A anterior fusion was a more risky procedure to the patient with poor general condition, severe adhesion and long destruction of the entire L5 & upper S1 vertebral body. Occurred 35 days after first operation. Curettage and debridement were again undertaken by the posterior approach on the second operation. However 45 days late, it recurred again. Therefore, we performed the anterior fusion as the third procedure and had a successful outcome. We believe that in some cases, the advantages of posterior approach and fusion may be a pitfall and should be carefully applied in the treatment of spine tuberculosis.

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.

Cervical Fusion with Conventional Plate and Screw Using the Technique of Purchasing Near Cortex / 대한정형외과학회잡지

Anterior plate fixation of the cervical spine enhance anterior grafting technique and provide good primary stability to allow early mobilization without significant external support. This facilitastes nursing and shortens rehabilitation time. Although these advantages, the screw technique is risky and time-consuming since purchasing of posterior cortex is needed for obtatining maximum stability. The authors have tried to a technique of purchasing only near cortex. The objectives of this study were review of the result of this technique and the determining the factor influencing screw loosening. One hundred and five screws used in twenty-one patients for conventional cervical plate fixation from September 1990 to February 1994 were reviewed. Average age was forty-two years old ranged from nineteen to sixty-five. Patients with trauma were six and degenerative diseases were fifteen. Two screws were inserted in C3 bodies, ten in C4, thirty-two in C5, thirty-four in C6, ten in C7, two in Tl and fifteen in grafted bone. Twenty-four screws(16%) in six patients(28.6%) were loosened. Usually the first loosening was noted at about one month after operation. The incidence of loosening was significantly higher in lower cervical region(p < 0.001) and older age(p < 0.05). The disease entity or sex were not significant factor. This technique showed high rate of screw loosening especially in older age group or lower cervical lesion. We think the indication of this technique should be limited in young patient with upper cervical lesion.

Clinical Experiences of Anterior Cervical Spine Fusion with the Caspar Plate

The anterior interbody fusion for cervical spine disease may not provide adequate immediate stabilization, but anterior cervical spine plating has overcome this main disadvantage. Between August 1991 and August 1992, twenty patients with a variety of cervical spine abnormalities were treated by anterior cervical spine fusion with the Caspar plate system. Fourteen patients had traumatic fracture and/or dislocation, three had infection(including two tuberculous spondylitis), two had degenerative spondylosis, and on had metastatic tumor. Single level fusion was accomplished in six patients, two-level fusion in eleven patients, and three-level fusion in three patients. Among seventeen patients with an incomplete transverse lesion or neck pain, all patients showed some recovery at discharge except two patients with Frankel grade D. Complications included screw loosening(one patient), dysphagia(one patient, which subsided after removal of the plate), and transient neurological worsening(one patient). All patients had good bony fusion except one which had screw loosening. Careful attention to surgical technique is needed to assure good results.

A Case of Curretage and Anterior Fusion of Cervical Tuberculous Spondylitis Via Trotter Approach

A ase of 47 years old female with cervical tuberculous spondylits involving C2,3 and C4 is reported. The lesion was treated surgically by curretage and anterior fusion with iliac bone autograft via median labiomandibular glossotomy.

A Case of Typical Thoracic Disc Herniation Treated by Transthoracic Transpleural Approach

Herniated thoracic discs are a rare cause of spinal cord compression. The lesions occur predominantly the fourth decade and protrusions between T9 and T12 account for approximated two thirds of cases. The diagnosis is difficult to make clinically due to variable presented symptoms. The myelography and spine CT scan are the most useful diagnostic aids. The authors present a case of typical herniated thoracic disc at T11/T12 who was treated by transthoracic transpleural approach with anterior fusion. The operative result was excellent.

Treatment of Ossification of Posterior Longitudinal Ligament in Cervical Spine with Anterior Fusion and Anterior Decompression: Report of 3 Cases / 대한정형외과학회잡지

Since ossification of posterior longitudinal ligament in cervical spine (O.P.L.L.) was presented at first by Tsukimoto in 1960, many cases have been reported in Japan. But very few cases were reported outside of Japan, including Korea. It is yet unknown what mechanism is the cause and why it is prevalent among the Japanese. And so, there are various theories on the cause. With progression, this lesion cas cause cervical myelopathy and radiculopathy. The treatment of O.P.L.L. is divided into conservative and operative treatment, and the latter is composed of anterior fusion,anterior decompression and posterior decompression. We experienced 3 cases of O.P.L.L. of which two cases were treated by anterior fusion and one tred by anterior decompression with partial removel of ossification mass from March, 1985 to May, 1986. On the follow-up, results were excellent to good. We report our experience in treatment of O.P.L.L. and recommand to be concerned about the lesion.