Three-Column Fracture in the Thoracolumbar Junction Caused by Low-Energy Trauma in a Patient with Baastrup Disease: A Case Report / 대한척추외과학회지

STUDY DESIGN: Case report.OBJECTIVES: We report a case of 3-column fracture caused by low-energy trauma in a patient with Baastrup disease who complained of acute radiating pain and motor weakness in the lower limbs after 3 weeks of conservative treatment. Subsequently, posterior fusion surgery was performed.SUMMARY OF LITERATURE REVIEW: Baastrup disease is characterized by enlargement and close approximation of adjacent spinous processes, and it mostly affects the L4-5 level of the spine. In patients with Baastrup disease affecting multiple levels of the lumbar spine, low-energy trauma can cause an unstable 3-column fracture with neurological compromise. Early recognition and surgical treatment prior to the emergence of a neurological deficit are required.MATERIALS AND METHODS: An 84-year-old woman presented with back pain after falling down backward and colliding with the edge of a shelf at ground level. Considering the patient's general condition and age, she was initially treated with close observation and placement of a spinal brace with serial radiographic follow-up.RESULTS: Computed tomography found 3-column fracture at the T11 level, which is quite rare in cases of minor trauma. At a 3-week follow-up, she complained of gradual lower extremity weakness, and her general lower extremity motor function decreased to grade 1–2. The patient underwent posterior fusion 2 levels above and below the affected vertebral body (T9-10-12-L1). Surgery was uneventful and the patient's motor function recovered.CONCLUSIONS: In patients with Baastrup disease affecting multiple levels of the lumbar spine, based on our experience, low-energy trauma can cause an unstable 3-column fracture with neurological compromise. We highly recommend scrutiny of the interspinous space in elderly patients, especially those with a spinal fracture caused by low-energy trauma.

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.

Risk Factors of Cage Subsidence after Posterior Lumbar Interbody Fusion

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of this study was to evaluate risk factors for subsidence after posterior lumbar interbody fusion (PLIF). SUMMARY OF LITERATURE REVIEW: Body mass index (BMI), bone mineral density (BMD), cage characteristics (titanium or poly-ether-ether-ketone (PEEK)) and degree of disc distraction are risk factors for cage subsidence after PLIF. MATERIALS AND METHODS: From January 2010 to January 2015, a total of 69 patients (93 segments) who were diagnosed with degenerative lumbar spine disease at the current authors' institution and underwent follow-up for at least 1 year were included in this retrospective study. Data on all factors related to cage subsidence were taken into consideration. The degree of association for each of the factors was determined through the calculation of odds ratios (ORs) with a 95% confidence interval. Logistic regression analyses were performed. The P-value that represented statistical significance was set below 0.05. RESULTS: There were no significant associations between fused segment level and cage subsidence (p=0.588), nor were there any significant associations between the kind of cage (titanium or PEEK) and cage subsidence (p=0.371). Using logistic regression, the factors with a P-value below the 0.20 level in univariate analyses were included in the multivariate analyses. In multivariate analyses, diabetes mellitus (DM) (p=0.029, OR, 4.524), osteoporosis (p=0.026, OR, 6.046), and degree of disc distraction (p=0.010, OR, 1.446) had significant associations with cage subsidence. In addition, there were significant associations between cage subsidence and instrument failure (p=0.008, OR, 8.235). CONCLUSIONS: DM and osteoporosis, which may affect bony structures, have significant associations with cage subsidence after PLIF. Cage insertion with excessive disc distraction during surgery may also affect cage subsidence after PLIF.

Posterior Fusion for Thoracolumbar Fractures with a Neurologic Deficit: A Comparison of Fusion and Additional Decompression

STUDY DESIGN: A retrospective study. OBJECTIVES: To understand the necessity of additional posterior decompression when treating a patient with posterior fusion for thoracolumbar fractures with a neurologic deficit. SUMMARY OF LITERATURE REVIEW: Additional posterior decompression is still controversial when treating a patient with posterior fusion for thoracolumbar fractures with neurologic a deficit. MATERIALS AND METHODS: 40 patients who underwent posterior fusion surgery for thoracolumbar fractures with a neurologic deficit were evaluated. The posterior fusion group (Group 1) included 23 patients (M:F=14:9), and the posterior decompression with laminectomy and posterolateral fusion group (Group 2) included 17 patients (M:F=9:8). According to the Frankel grade, the most common neurologic deficit was grade D in both groups. Unstable burst fractures were the most commonly observed fractures in both groups according to the McAfee classification. A radiographic evaluation was carried out along with a comparison of the spinal canal encroachment and the kyphotic angle. We evaluated neurologic improvement as the clinical criterion. RESULTS: The l-kyphotic angle at last follow-up was smaller than the preoperative kyphotic angle in both groups. The preoperative canal encroachment was 53.4% (Group 1) and 59.8% (Group 2). Further, neurologic improvement was observed in 19 cases (Group 1) and 14 cases (Group 2). There was no significant difference in the proportion of cases with neurologic improvement between the two groups (improvement in 19 cases in Group 1 and in 14 cases in Group 2) (p0.05). CONCLUSION: We concluded that additional posterior decompression in the case of thoracolumbar fractures with neurologic deficit is not required for neurologic improvement.

Replacement of Vertebral Lamina (Laminoplasty) in Surgery for Lumbar Isthmic Spondylolisthesis: 5-Year Follow-Up Results

STUDY DESIGN: A review of clinical and radiological outcomes of lumbar laminoplasty (LL) for the treatment of isthmic spondylolisthesis (ISL). PURPOSE: The single session performance of posterior lumbar interbody fusion with allograft in the anterior column and providing the realignment of the vertebrae was presented as a preliminary report earlier. OVERVIEW OF LITERATURE: Long-term surgical outcome of cervical laminoplasty in patients has been reported. But, outcome of LL in patients is unclear. METHODS: The long-term (5 years) year follow-up results of the LL technique are reported in this retrospective study. All patients underwent preoperative and postoperative direct X-ray, computed tomography, and magnetic resonance imaging. The patients that did not respond to conservative treatment were operated. Twenty-one (52.5%) female and 19 (47.5%) male patients were included. RESULTS: Mean age was 43,5 years (ranges, 22-57 years). The most common symptoms were low back pain (89%), pelvic and leg pain (69%) and reduction in walking distance (65%). A total of 180 pedicle screws were inserted in 40 patients; posterior lumbar interbody fusion and laminoplasty with reduction was performed in 20 patients for L4-L5, 12 patients for L5-S1, 4 patients for L3-L4-L5 and 4 patients for L4-L5-S1. Ten (25%) patients with ILL had accompanying spinal stenosis. The difference between preoperative and postoperative sagittal plane rotation and dislocation degrees and disc space heights were statistically significant in all patients (p<0.05). Solid grade 4 fusion was observed in 38 patients; in only 2 patients grade 2 pseudoarthrosis developed (5%), but these patients were asymptomatic. Visual analog scale, Prolo economical and functional scale was examined with an average follow-up 5.5 years. CONCLUSIONS: LL technique has the advantages of shorter duration of operation, lack of graft donor site complications, protection of posterior column osseoligamentous structures and achievement of high fusion rates in one session.

Replacement of Vertebral Lamina (Laminoplasty) in Surgery for Lumbar Isthmic Spondylolisthesis: 5-Year Follow-Up Results

STUDY DESIGN: A review of clinical and radiological outcomes of lumbar laminoplasty (LL) for the treatment of isthmic spondylolisthesis (ISL). PURPOSE: The single session performance of posterior lumbar interbody fusion with allograft in the anterior column and providing the realignment of the vertebrae was presented as a preliminary report earlier. OVERVIEW OF LITERATURE: Long-term surgical outcome of cervical laminoplasty in patients has been reported. But, outcome of LL in patients is unclear. METHODS: The long-term (5 years) year follow-up results of the LL technique are reported in this retrospective study. All patients underwent preoperative and postoperative direct X-ray, computed tomography, and magnetic resonance imaging. The patients that did not respond to conservative treatment were operated. Twenty-one (52.5%) female and 19 (47.5%) male patients were included. RESULTS: Mean age was 43,5 years (ranges, 22-57 years). The most common symptoms were low back pain (89%), pelvic and leg pain (69%) and reduction in walking distance (65%). A total of 180 pedicle screws were inserted in 40 patients; posterior lumbar interbody fusion and laminoplasty with reduction was performed in 20 patients for L4-L5, 12 patients for L5-S1, 4 patients for L3-L4-L5 and 4 patients for L4-L5-S1. Ten (25%) patients with ILL had accompanying spinal stenosis. The difference between preoperative and postoperative sagittal plane rotation and dislocation degrees and disc space heights were statistically significant in all patients (p<0.05). Solid grade 4 fusion was observed in 38 patients; in only 2 patients grade 2 pseudoarthrosis developed (5%), but these patients were asymptomatic. Visual analog scale, Prolo economical and functional scale was examined with an average follow-up 5.5 years. CONCLUSIONS: LL technique has the advantages of shorter duration of operation, lack of graft donor site complications, protection of posterior column osseoligamentous structures and achievement of high fusion rates in one session.

Comparison of Short Segment and Long Segment Posterior Instrumentation of Thoracolumbar and Lumbar Bursting Fractures at Load Sharing Score 7 or Above

STUDY DESIGN: A retrospective comparative analysis of the short-segment and long-segment posterior fixation in thoracolumbar burst fractures that are 7 points or above in load-sharing score was performed. OBJECTIVES: The purpose of this study is to demonstrate the appropriate level of fixation by comparing the results of short-segment and long-segment posterior fixation. SUMMARY OF LITERATURE REVIEW: There is general consensus that short-segment fixation should be done in thoracolumbar burst fractures that are 6 points or less in load-sharing classification. There is some controversy regarding whether short-segment or long-segment fixation should be done in thoracolumbar burst fractures that are 7 points or above in load-sharing classification. MATERIALS AND METHODS: From 1998 through 2008, 32 patients with thoracolumbar burst fractures above 7 points in load-sharing classification had been operated with short-segment (1 segment above and 1 segment below: 23 patients) or long-segment (2 segments above and 1 segment below: 9 patients) transpedicular screw fixation at the author's institution. They were divided by two groups (group I: short-segment fixation, group II: long-segment fixation). The mean age of patients was 49.2 years old and the mean follow-up period was 2.4 years (1-7 years). In preoperative and postoperative simple radiographs, the bony unions, breakages or loosening of implants were assessed, and the losses of correction angle and anterior vertebral body height were measured. RESULTS: In all cases, non-union or loosening of implants were not observed. There was 1 screw breakage in short-segment fixation group during the follow up period, but bony union was obtained at final follow-up. The mean score of load sharing classification was 7.3 in Group I and 7.1 in Group II, and there was no significant difference between two groups. (p>0.05) The mean anterior vertebral body height loss was 5.3% in Group I and 3.6% in Group II and the mean loss of correction angle were 4.72 in Group I and 3.38 in Group II. There was no significant difference between the two groups for both. (p>0.05) CONCLUSIONS: There was no significant difference in radiologic parameters between two groups. Short-segment fixation could be used successfully in selected cases of thoracolumbar burst fractures that are 7 points or above in load-sharing classification.

Normal Range of the Inflammation Related Laboratory Findings and Predictors of the Postoperative Infection in Spinal Posterior Fusion Surgery

BACKGROUND: Inflammation related hematological parameters vary greatly depending on patients. It is not well known how much increase of which parameter warrants suspicion of postoperative infection. This study proposes to identify the normal range and the predictive factors for postoperative infection by conducting a time series analysis of the hematological parameters of patients after the spinal posterior fusion. METHODS: A retrospective study was done with 608 patients who underwent spinal posterior fusion with pedicle screw fixation. Laboratory assessment including the leucocyte, neutrophil, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) of patients for 2 weeks after operation. The patients were divided into the one-level fusion group (group I), the two-level fusion group (group II), the three or multi-level fusion or reoperation group (group III), and the postoperative infection group (group IV). Blood was drawn before breakfast prior to the operation, and then 2-3 days, 4-7 days, 8-11 days, and 12-14 days after the operation. The leucocyte count, neutrophil count, CRP, and ESR were measured. RESULTS: From 4-7 days after the operation, the CRP and neutrophil count of group IV were significantly higher than those of group I and II, and from 8-11 days after operation, the CRP and neutrophil counts were significantly higher than those of all groups. Twelve to fourteen days after the operation, the neutrophil count of group IV was significantly higher than that of group I and II, while the neutrophil count of group III was also higher than that of group I. The lower limit of the 95% confidence interval (CI) of the CRP and neutrophil count group IV was greater than the upper limit of the 95% CI of group I and II. The ESR of group IV was significantly higher than that of group I and III. CONCLUSIONS: If the postoperative CRP and neutrophil counts are high, or if the CRP begins to rise again 8 days after the operation, the likelihood of infection increases, but caution must be exercised in interpreting the results. If the hematological parameters are higher than the lower limit of the 95% CI of the postoperative infection group, infection must be strongly suspected.

Single-Stage Removal of Thoracic Dumbbell Tumors from a Posterior Approach Only with Costotransversectomy

PURPOSE: Thoracic dumbbell tumors are relatively rare, usually arising from neurogenic elements. Methods for surgical removal thereof remain controversial. The purpose of this study was to evaluate the surgical results of a single-stage posterior approach with laminectomy and costotransversectomy only for the management of thoracic dumbbell tumors. MATERIALS AND METHODS: Eight cases of thoracic large dumbbell tumor were analyzed retrospectively: seven men and one woman (mean age, 49 years). Pathologic findings included schwannoma in five patients, neurofibroma in two patients (Recklinghausen in one patient), and ganglioneuroma in one patient. All patients underwent single-stage removal of dumbbell tumors by a posterior approach followed by laminectomy and costotransversectomy combined with instrumentation. Clinical and radiologic outcomes were reviewed, thereafter. RESULTS: Operative time ranged from 185 to 420 minutes (mean, 313 minutes), with estimated blood loss ranging from 71 to 1830 mL (mean, 658 mL). Postoperative complications included atelectasis in one case. All patients had tumors successfully removed with no neurological deterioration. Spinal deformities were not observed in any patients at the last follow-up (mean, 52 months), with instrumentation. CONCLUSION: Single-stage surgery with laminectomy and costotransversectomy may be useful for removing thoracic dumbbell tumors without a combined anterior approach.

Botulinum Toxin Treatment prior to Posterior Spinal Fusion for Cervical Spondylotic Myelopathy in Patients with Athetoid Cerebral Palsy : A Report on Two Cases / The Japanese Journal of Rehabilitation Medicine

There have been several reports on surgical interventions in patients with adult cervical spondylotic myelopathy associated with cerebral palsy. We performed posterior fusion with pedicle and/or lateral mass screws combined with preoperative intramuscular injections of botulinum toxin in two patients. Two weeks before the surgery, we injected the patients with the botulinum toxin to alleviate cervical pain and to reduce the involuntary movement associated with cerebral palsy. Surgical results were good in both patients without rigid external fixation. Both patients were able to undergo rehabilitation after the surgery as soon as possible without any complication. We think that our pre surgical treatment with botulinum toxin is a useful optional treatment for cervical spondylotic myelopathy associated with cerebral palsy.

Artrodesis lumbosacra mediante el sistema TRAUSON / Lumbosacral arthrodesis by TRAUSON system / Arthrodèse lombo-sacrée par système TRAUSON

INTRODUCCIÓN. En 1891 se colocó por vez primera una sutura de alambre de plata para la estabilización y fusión de la columna toracolumbar y desde entonces se han desarrollado múltiples técnicas para este propósito. En el 2008 se comenzó a utilizar en el Hospital Ortopédico «Fructuoso Rodríguez¼ el sistema TRAUSON, de procedencia china. El objetivo del presente artículo fue mostrar los resultados obtenidos con dicha técnica para el tratamiento de 6 pacientes con afección de la columna lumbosacra. MÉTODOS. Se revisaron las historias clínicas y estudios imagenológicos de pacientes con fusión lumbosacra en los que se utilizó el sistema transpedicular TRAUSON, entre abril del 2008 y enero del 2009. En este período se realizaron 18 instrumentaciones, 6 de las cuales incluían el segmento L5-S1 que es el grupo control del presente trabajo. Se correlacionaron el cuadro clínico pre y posoperatorio, y los estudios imagenológicos disponibles. Se analizaron los datos siguientes: sexo, edad, patología de base, tiempo quirúrgico y grado de satisfacción según los escalas EVA y de Oswestry. RESULTADOS. En el 100 % de los casos la evolución fue buena si se tiene en cuenta que se superaron los síntomas iniciales que motivaron la cirugía. Cinco pacientes presentaron dolor residual en la articulación sacroilíaca, que mejoró entre el segundo y tercer mes con tratamiento fisioterapéutico. No se utilizaron infiltraciones u otros métodos invasivos. Entre las complicaciones posquirúrgicas se registraron 2 casos de reacción al material de sutura, y no hubo ni sepsis ni dehiscencia de la herida quirúrgica. CONCLUSIONES. El sistema TRAUSON permite una fijación estable útil para el tratamiento de patologías en esta zona y permite también una movilización precoz de los pacientes. Es altamente aceptado por éstos.

INTRODUCTION: In 1981 for the first time a silver wire suture was placed for stabilization and fusion of thoracolumbar spine and from then multiple techniques have been developed to this end. At 2008 the TRAUSON system was used for the first time in “Fructuoso Rodríguez” Orthopedics Hospital originating in China. The aim of present article was to shows the results obtained with this technique for treatment of 6 patients presenting with lumbosacral spine affection. METHODS: We made a review of medical records and imaging studies from patients with lumbosacral fusion using the TRAUSON system from April, 2008 to 2009. During this period 18 instrumentations were performed, where six included the L5-S1 segment (control group). Preoperative and postoperative clinical picture were correlated with the available imaging studies. Following data were analyzed: sex, age, baseline pathology, surgical time and satisfaction level according the EVA and Oswestry scales. RESULTS: In the 100% of cases the course was good if we considered that first symptoms causing surgery were overcome. Five patients had residual pain in sacroiliac joint improving between the second and the third month with physiotherapy. Neither infiltrations nor other invasive methods were used. Among the postsurgical complications were two cases of reaction to suture material without sepsis and surgical wound dehiscence. CONCLUSIONS: TRAUSON system allows a stable fixation useful for treatment of pathologies in this zone and also an early mobilization of patients. This system is very well accepted by patients.

INTRODUCTION. En 1891, la suture avec fil en argent a été utilisée pour la première fois dans la stabilisation et la fusion du rachis thoraco-lombaire, et depuis lors de multiples techniques ont été développées à ce fin. En 2008, le système TRAUSON, d'origine chinoise, a commencé à être utilisé à l'Hópital d'orthopédie “Fructuoso Rodríguez”. Le but de cet article est de montrer les résultats obtenus avec cette dite technique dans le traitement de 6 patients avec une affection du rachis lombo-sacré. MÉTHODES. Tous les dossiers médicaux et les examens d'imagerie des patients atteints d'une fusion lombo-sacrée ont été examinés à l'aide du système transpédiculaire TRAUSON entre avril 2008 et janvier 2009. Dans cette période, on a réalisé 18 instrumentations, dont 6 ont inclus le segment L5-S1, étant le groupe-contrôle de cette étude. Les tableaux cliniques pré- et postopératoire et les examens d'imagerie disponibles ont été comparés. Les variables telles que sexe, âge, pathologie de base, temps chirurgical et grade de satisfaction, d'après les scales EVA et d'Oswestry, ont été aussi analysées. RÉSULTATS. Dans 100% des cas, l'évolution a été satisfaisante si on tient compte de l'amélioration des premiers symptômes causant la chirurgie. Cinq patients ont subi une douleur résiduelle au niveau de l'articulation sacro-ilîaque qui s'est soulagée en deux et trois mois avec kinésithérapie. On n'a pas utilisé d'infiltrations ni d'autres méthodes invasives. Parmi les complications postchirurgicales, on a trouvé deux cas de réactions au matériel de suture, mais il n'y a pas eu d'infection ni de déhiscence dans la blessure chirurgicale. CONCLUSIONS. Le système TRAUSON permet une fixation stable dans le traitement des pathologies de cette région anatomique, et permet aussi une mobilisation précoce des patients. Il est hautement accepté par eux.

The Surgical Treatment of the Cervical Myelopathy with Laminectomy and Posterior Fusion by using Lateral Mass Screw Fixation / 대한정형외과학회잡지

PURPOSE: This prospective study was designed to investigate the outcomes of laminectomy and fusion with using lateral mass screw (LMS) fixation for the treatment of cervical myeolpathy. MATERIALS AND METHODS: We studied a series of 26 consecutive patients with cervical myelopathy and who were planned to undergo laminectomy and fusion with using LMS fixation. MRI was done to investigate the high signal intensity lesion (HSIL) in the cord on the T2 weighted sagittal images. The JOA score, the grip and release test, the finger escape sign, and Hoffman's sign were checked. We analyzed the clinical outcomes depending on the high signal intensity lesion in the cord, the preoperative kyphosis, and the preoperative instability. RESULTS: The indications for lateral mass screw fixation was kyphotic deformity, segmental instability or ossification of the ligament flavum (OLF). Patients with HSIL on the T2-weighted sagittal MRI was found in 17 patients. The JOA score, the grip and release test, and the finger escape sign were significantly improved after the operation and at the 2 year follow up. The patients with HSIL on the T2-weighted sagittal MRI or segmental instability had a significantly lower preoperative JOA score and a poor postoperative recovery as assessed by the JOA score. CONCLUSION: Laminectomy and fusion using lateral mass screw fixation for the surgical treatment of cervical myelopathy, which is associated with kyphotic deformity, instability or OLF, is considered a safe and effective treatment option to prevent postoperative kyphosis.

The Quantitative Analysis of Back Muscle Degeneration after Posterior Lumbar Fusion: Comparison of Minimally Invasive and Conventional Open Surgery

STUDY DESIGN: Prospective controlled study. PURPOSE: The results of conventional open surgery was compared with those from minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for lumbar fusion to determine which approach resulted in less postoperative paraspinal muscle degeneration. OVERVIEW OF LITERATURE: MI TLIF is new surgical technique that appears to minimize iatrogenic injury. However, there aren't any reports yet that have quantitatively analyzed and proved whether there's difference in back muscle injury and degeneration between the minimally invasive surgery and conventional open surgery in more than 1 year follow-up after surgery. METHODS: This study examined a consecutive series of 48 patients who underwent lumbar fusion in our hospital during the period, March 2006 to March 2008, with a 1-year follow-up evaluation using MRI. There were 17 cases of conventional open surgery and 31 cases of MI-TLIF (31 cases of single segment fusion and 17 cases of multi-segment fusion). The digital images of the paravertebral back muscles were analyzed and compared using the T2-weighted axial images. The point of interest was the paraspinal muscle of the intervertebral disc level from L1 to L5. Picture archiving and communication system viewing software was used for quantitative analysis of the change in fat infiltration percentage and the change in cross-sectional area of the paraspinal muscle, before and after surgery. RESULTS: A comparison of the traditional posterior fusion method with MI-TLIF revealed single segment fusion to result in an average increase in fat infiltration in the paraspinal muscle of 4.30% and 1.37% and a decrease in cross-sectional area of 0.10 and 0.07 before and after surgery, respectively. Multi-segment fusion showed an average 7.90% and 2.79% increase in fat infiltration and a 0.16 and 0.10 decrease in cross-sectional area, respectively. Both single and multi segment fusion showed less change in the fat infiltration percentage and cross-sectional area, particularly in multi segment fusion. There was no significant difference between the two groups in terms of the radiologic results. CONCLUSIONS: A comparison of conventional open surgery with MI-TLIF upon degeneration of the paraspinal muscle with a 1 year follow-up evaluation revealed that both single and multi segment fusion showed less change in fat infiltration percentage and cross-sectional area in the MI-TLIF but there was no significant difference between the two groups. This suggests that as time passes after surgery, there is no significant difference in the level of degeneration of the paraspinal muscle between surgical techniques.

Early Results from Posterior Cervical Fusion with a Screw-Rod System

PURPOSE: We performed 65 cases of posterior fusion surgery for cervical and/or high thoracic lesions using a polyaxial screw-rod system. PATIENTS AND METHODS: A total of 486 screws were implanted in 65 patients. RESULTS: Fixation of the screws was carried out over an average of 2.9 spinal segments. Upon evaluation by postoperative CT scans, twelve (2.5%) screws had suboptimal trajectories but two of these revealed radiculopathy in one patient and required screw repositioning. No vascular sequelae resulted. There has been no segmental motion in any of the cases to date. As for other complications, there was one case of dural tearing and two cases of lateral mass fractures. There were no infections or other wound healing problems or hardware failures. No patients had neurological deterioration after surgery. There were statistically significant improvements in the mean Neck Disability Index (NDI) scores and Visual Analogue Scale (VAS) scores in the preoperative and late postoperative follow-up evaluations. Although further studies are required to establish the long-term results of fusion rates and clinical outcomes. CONCLUSION: We cautiously suggest that the posterior polyaxial screw-rod system can be safely used as a primary or additional fusion method in this risky region. The successful and safe use of this method is dependent on a precise preoperative surgical plan and tactics for ensuring safe screw fixation.

Posterior Atlantoaxial Transarticular Screw Fixation

OBJECTIVE: Posterior arthrodesis in atlantoaxial instability has been performed using various posterior C1-2 wiring techniques. Recently, transarticular screw fixation (TASF) technique was introduced to achieve significant immediate stability of the C1-2 joint complex. The purpose of this study is to assess the clinical outcomes associated with posterior C1-2 TASF for the patient of atlantoaxial instability. METHODS: We retrospectively reviewed data obtained from 17 patients who underwent C1-2 TASF and supplemented Posterior wiring technique (PWT) with graft between 1994 and 2005. There were 8 men and 9 women with a mean age of 43.5 years (range, 12-65 years). An average follow-up was 26 months (range, 15-108 months). RESULTS: Successful fusions were achieved in 16 of 17 (94%). The pain was improved markedly (3 patients) or resolved completely (14 patients). There was no case of neurological deterioration, hypoglossal nerve injury, or vertebral artery injury. Progression of spinal deformity, screw pullout or breakage, and neurological or vascular complications did not occur. CONCLUSION: The C1-2 TASF with supplemental wiring provided a high fusion rate. Our result demonstrates that C1-2 TASF supplemented by PWT is a safe and effective procedure for atlantoaxial instability. Preoperative evaluation and planning is mandatory for optimal safety.

Posterior Atlantoaxial Transarticular Screw Fixation

OBJECTIVE: Posterior arthrodesis in atlantoaxial instability has been performed using various posterior C1-2 wiring techniques. Recently, transarticular screw fixation (TASF) technique was introduced to achieve significant immediate stability of the C1-2 joint complex. The purpose of this study is to assess the clinical outcomes associated with posterior C1-2 TASF for the patient of atlantoaxial instability. METHODS: We retrospectively reviewed data obtained from 17 patients who underwent C1-2 TASF and supplemented Posterior wiring technique (PWT) with graft between 1994 and 2005. There were 8 men and 9 women with a mean age of 43.5 years (range, 12-65 years). An average follow-up was 26 months (range, 15-108 months). RESULTS: Successful fusions were achieved in 16 of 17 (94%). The pain was improved markedly (3 patients) or resolved completely (14 patients). There was no case of neurological deterioration, hypoglossal nerve injury, or vertebral artery injury. Progression of spinal deformity, screw pullout or breakage, and neurological or vascular complications did not occur. CONCLUSION: The C1-2 TASF with supplemental wiring provided a high fusion rate. Our result demonstrates that C1-2 TASF supplemented by PWT is a safe and effective procedure for atlantoaxial instability. Preoperative evaluation and planning is mandatory for optimal safety.

Deep Infection following Instrumented Posterior Fusion / 대한정형외과학회잡지

PURPOSE: This study evaluated the diagnosis, treatment and related results for cases with a deep infection after instrumented posterior fusion. MATERIALS AND METHODS: Among the 306 cases of posterior instrumented spinal fusion, Seventeen cases who developed deep infection were reviewed retrospectively. RESULTS: The incidence of deep infections was 5.6% and the mean age of the cases with a deep infection was 55 years old. Nine out of 17 cases had the preoperative risk factors such as old age, diabetes, malnutrition, obesity, etc. The mean duration to diagnosis of a postoperative infection was 12.9 days (4-8 days). The clinical manifestations were fever, night pain and abscess drainage. In all cases, the value of the WBC, ESR and CRP were elevated. All cases were treated surgically as soon as possible with abscess drainage, debridement and the insertion of antibiotics-mixed cement beads without the removal of the instrument. The most common bacterial organisms were Coagulase negative Staphylococcus aureus in 11 cases. Vancomycin was used as the antibiotic. During the follow-up period, 2 cases were treated with the removal of the instruments due to metal failure and a delayed deep infection with loosening. The average follow-up was 32 months (12-56 months). 15 cases were controlled successfully without needing to remove the instruments and without complications. CONCLUSION: The meticulous care for a deep infection after posterior instrumented spinal fusion is essential. Favorable results can be achieved by surgery with drainage, debridement, and the insertion of antibiotics-mixed cement beads along with systemic antibiotics as soon as possible without removing the instruments.

The Effects of Stiffness in Transverse Ligament and Wire Diameter on Atlanto-Axial Posterior Fixations / 대한정형외과연구학회지

PURPOSE: To analysis the effects of reduction of stiffness in transverse ligament and wire diameter on atlanto-axial posterior fusion and fixations using finite element model. MATERIALS AND METHODS: The finite element model of occipito-atlanto-axis was made based on cadaver with a normal occiput and cervical spine. In order to investigate the effects of the wire diameter on the posterior fusion and fixations, an unstable atlanto-axial finite element model was made to reduce stiffness of the transverse ligament orderly (50%, 75%, 100%). And the wire was tied according to Brooks and Jenkins'method after modeling the grafted bone to fit in the space between the atlas and axis. The wire diameter was 18G, 20G and 22G. Anterior atlanto-dens interval (AADI) was measured after placing 1.5 Nm pure flexion movement on the occiput. RESULTS: The AADI was increased as the stiffness of transverse ligament was reduced. In the case of 50%, 75% and 100% decrement, the AADI were 3.37 mm, 3.87 mm and 4.94 mm. In the case of 50% and 75% decrement, the sufficient fixations were obtained although we used thin wire. However, in the 100% decrement, the AADI was exceeded the 3 mm when we used thin wire (20G, 22G) and sufficient fixations were obtained with only 18G. CONCLUSION: The sufficient fixations were obtained regardless of wire diameter in the partial tear of transverse ligament. In the complete tear, the minimal 18G wire diameter was useful to acquire sufficient fixations. However, the results were derived from the finite element model analysis. Thus further verification should be necessary to confirm the results using cadaver experiments.

Surgical Outcome of Degenerative Lumbar Spinal Stenosis in Patients over 70 years old: A Comparative Analysis according to Surgical Method / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To analyze and compare the clinical results of different surgical methods for spinal stenosis, without lumbar instability, in patients over 70 years-old. SUMMARY OF LITERATURE REVIEW: Much controversy exists as to the best operative method for spinal stenosis. MATERIALS AND METHODS: Thirty eight patients that had undergone surgical treatment for spinal stenosis, without lumbar spinal instability, with a mean age of 75.1 years(70 to 91 years) and follow up period was 44 months(24 to 52 months), were retrospectively reviewed. The patients were divided into two groups: * Group A (n=23): posterior decompression alone * Group B (n=15): posterior decompression and posterolateral fusion Clinical outcome and satisfaction were assessed using Bohlman's measurements, on a 10 point pain rating scale, and the clinical outcomes were further analyzed according to the co-morbidity and postoperative complications. RESULTS: Clinically excellent and good outcomes were achieved in 86.9 and 80.0% in groups A and B, respectively. The 10-points pain scale for low back pain showed improvements in both groups. The co-morbidity did not influence the clinical outcome in either group. There were no serious postoperative complications in either group. CONCLUSIONS: Posterior decompression alone was an effective surgical method, and was found to be equivalent to posterior decompression and posterolateral fusion in patients over 70 years-old with degenerative lumbar spinal stenosis and without lumbar spinal instability.

Treatment of Vertebral Pseudarthrosis after Compression Fracture

PURPOSE: To clarity the features of vertebral pseudarthrosis and to evaluate the efficacy of posterior instrumentation and fusion in treatment of it. MATERIALS AND METHODS: Twelve patients with severe back pain and intravertebral pseudarthrosis showing vacuum phenomenon were treated by in situ posterior instrumentation and fusion. The kyphotic angle of pre- and post-treatment was measured on a lateral radiograph. MRI was performed in all patients. The intravertebral instability was confirmed from the dynamic lateral view. The pain level was assessed both before and after the treatment using a visual analog scale. The kyphotic angle at last follow up was also checked. RESULTS: In eight cases, intravertebral instability was shown at the clefts in flexion-extension radiographs. MRI showed that the cleft was low intensity on the T1- weighted image and high intensity on the T2-weighted image. The pre-and postoperative mean kyphotic angles were -18.3degrees and -8.5degrees respectively. The preoperative average pain score was nine and postoperative four. At last follow up the mean kyphotic angle was -16.6degrees CONCLUSION: The cleft with intravertebral vacuum phenomenon and magnetic resonance findings of low intensity on the T1-weighted scans and high intensity on the T2-weighted scans suggests that the cleft is a pseudarthrosis associated with avascular necrosis of the vertebral body. The posterior instrumentation and fusion provides satisfactory pain relief in patient with vertebral pseudarthsosis.