• Journal of Korean Neurosurgical Society
• /
• v.41 no.2
• /
• pp.88-94
• /
• 2007

Objective : The aim of this study is to investigate predictable risk factors for radiologic degeneration of adjacent segment after lumbar fusion and preoperative radiologic features of patients who underwent additional surgery with adjacent segment degeneration. Methods : Between January 1995 and December 2002, 201 patients who underwent lumbar fusion for degenerative conditions of lumbar spine were evaluated. We studied radiologic features, the method of operation, the length of fusion, age, sex, osteoporosis, and body mass index. Special attention was focused on, preoperative radiologic features of patients who required additional surgery were studied to detect risk factors for clinical deterioration. Results : Follow-up period ranged from 3 to 11 years. In our study, 61 [30%] patients developed adjacent segment degeneration, and 15 [7%] patients required additional surgery for neurologic deterioration. Age, the postoperative delay, facet volume, motion range, laminar inclination, facet tropism, and preexisting disc degeneration of adjacent segment considered as possible risk factors. Among these, laminar inclination and preexisting disc degeneration of adjacent segment were significantly correlated with clinical deterioration. Conclusion : The radiologic degeneration of adjacent segment after lumbar fusion can be predicted in terms of each preoperative radiologic factor, age and the postoperative delay. Laminar inclination and preexisting disc degeneration of adjacent segment have shown as strong risk factors for neurologic deterioration. Thus, careful consideration is warranted when these risk factors are present.

• Journal of Korean Neurosurgical Society
• /
• v.57 no.2
• /
• pp.108-113
• /
• 2015

Objective : Although the L5-S1 has distinct structural features in comparison with other lumbar spine segments, not much is known about adjacent segment degeneration (ASD) at the L5-S1 segment. The aim of study was to compare the incidence and character of ASD of the cephalad and L5-S1 segments after L5 floating lumbar fusion. Methods : From 2005 to 2010, 115 patients who underwent L5 floating lumber fusion were investigated. The mean follow-up period was 46.1 months. The incidence of radiological and clinical ASD of the cephalad and the L5-S1 segments was compared using survival analysis. Risk factors affecting ASD were analyzed using a log rank test and the Cox proportional hazard model. Results : Radiological ASD of the L5-S1 segment had a statistically significant higher survival rate than that of the cephalad segment (p=0.001). However, clinical ASD of the L5-S1 segment was significantly lower survival rates than that of the cephalad segment (p=0.038). Risk factor analysis showed that disc degeneration of the cephalad segment and preoperative spinal stenosis of the L5-S1 segment were risk factors. Conclusion : In L5 floating fusion, radiological ASD was more common in the cephalad segment and clinical ASD was more common in the L5-S1 segment. At the L5-S1 segment, the degree of spinal stenosis appears to be the most influential risk factor in ASD incidences, unlike the cephalad segment.

• Journal of Korean Neurosurgical Society
• /
• v.59 no.2
• /
• pp.129-136
• /
• 2016

Objective : The purpose of this study was to figure out the radiologic findings and risk factors related to adjacent segment degeneration (ASD) after anterior cervical discectomy and fusion (ACDF) using 3-year follow-up radiography, computed tomography (CT), and magnetic resonance image (MRI). Methods : A retrospective matched comparative study was performed for 64 patients who underwent single-level ACDF with a cage and plate. Radiologic parameters, including upper segment range of motion (USROM), lower segment range of motion (LSROM), upper segment disc height (UDH), and lower segment disc height (LDH), clinical outcomes assessed with neck and arm visual analogue scale (VAS), and risk factors were analyzed. Results : Patients were categorized into the ASD (32 patients) and non-ASD (32 patients) group. The decrease of UDH was significantly greater in the ASD group at each follow-up visit. At 36 months postoperatively, the difference for USROM value from the preoperative one significantly increased in the ASD group than non-ASD group. Preoperative other segment degeneration was significantly associated with the increased incidence of ASD at 36 months. However, pain intensity for the neck and arm was not significantly different between groups at any post-operative follow-up visit. Conclusion : The main factor affecting ASD is preoperative other segment degeneration out of the adjacent segment. In addition, patients over the age of 50 are at higher risk of developing ASD. Although there was definite radiologic degeneration in the ASD group, no significant difference was observed between the ASD and non-ASD groups in terms of the incidence of symptomatic disease.

• Journal of Korean Neurosurgical Society
• /
• v.42 no.3
• /
• pp.184-190
• /
• 2007

Objective : The authors retrospectively analyzed clinical and radiographic features of patients who developed symptomatic adjacent segment degeneration (ASD) that required re-operation. Methods : From 1995 to 2004, among 412 patients who underwent posterior lumbar fusion surgery, the authors experienced twenty-six patients who presented symptomatic ASD. Records of these patients were reviewed to collect clinical data at the first and second operations. Results : The patients were 9 males and 17 females whose mean age was $63.5{\pm}8.7$ years. Among 319 one segment and 102 multi-segment fusions, 16 and 10 patients presented ASD, respectively. Seventeen ASDs were noticed at the cephalad to fusion (65%), eight at the caudad (31%), and one at the cephalad and caudad, simultaneously (4%). All patients underwent decompression surgery. Nine patients underwent additional fusion surgeries to adjacent degenerated segments. In 17 patients who underwent only decompression surgery without fusion, the success rate was 82.4%. In fusion cases. the success rate was observed as 55.5%. There were no statistically significant factors to be related to development of ASD. However, in cases of multi-level fusion surgery, there was a tendency toward increasing ASD. Conclusion : Multi-segment fusion surgery could be associated with a development of ASD. In surgical treatment of symptomatic ASD, selective decompression without fusion may need to be considered as a primary procedure, which could reduce the potential risk of later occurrence of the other adjacent segment disease.

• Journal of Korean Neurosurgical Society
• /
• v.45 no.2
• /
• pp.81-84
• /
• 2009

Objective : Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. Methods : The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. Results : Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. Conclusion : If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.

• Asian Spine Journal
• /
• v.12 no.6
• /
• pp.1092-1099
• /
• 2018

Study Design: In-vitro biomechanical investigation. Purpose: To evaluate the biomechanical effects of the degeneration of the biodegradable cervical plates developed for anterior cervical discectomy and fusion (ACDF) on fusion and adjacent levels. Overview of Literature: Biodegradable implants have been recently introduced for cervical spine surgery. However, their effectiveness and safety remains unclear. Methods: A linear three-dimensional finite element (FE) model of the lower cervical spine, comprising the C4-C6 vertebrae was developed using computed tomography images of a 46-year-old woman. The model was validated by comparison with previous reports. Four models of ACDF were analyzed and compared: (1) a titanium plate and bone block (Tita), (2) strong biodegradable plate and bone block (PLA-4G) that represents the early state of the biodegradable plate with full strength, (3) weak biodegradable plate and bone block (PLA-1G) that represents the late state of the biodegradable plate with decreased strength, and (4) stand-alone bone block (Bloc). FE analysis was performed to investigate the relative motion and intervertebral disc stress at the surgical (C5-C6 segment) and adjacent (C4-C5 segment) levels. Results: The Tita and PLA-4G models were superior to the other models in terms of higher segment stiffness, smaller relative motion, and lower bone stress at the surgical level. However, the maximal von Mises stress at the intervertebral disc at the adjacent level was significantly higher in the Tita and PLA-4G models than in the other models. The relative motion at the adjacent level was significantly lower in the PLA-1G and Bloc models than in the other models. Conclusions: The use of biodegradable plates will enhance spinal fusion in the initial stronger period and prevent adjacent segment degeneration in the later, weaker period.

• Journal of Korean Neurosurgical Society
• /
• v.46 no.5
• /
• pp.425-430
• /
• 2009

Objective : The present study analyzed the risk factors, prevalence and clinical results following revision surgery for adjacent segment degeneration (ASD) in patients who had undergone lumbar fusion. Methods : Over an 8-year period, we performed posterior lumbar fusion in 81 patients. Patients were followed a minimum of 2 years (mean 5.5 years). During that time, 9 patients required revision surgery due to ASD development. Four patients underwent autogenous posterolateral arthrodesis and extended transpedicle screw fixation, 4 patients underwent decompressive laminectomy and interspinous device implantation, and 1 patient underwent simple decompression. Results : Of the 9 of patients with clinical ASD, 33.3% (3 of 9) of patients did not have radiographic ASD on plain radiographs. Following revision surgery, the clinical results were excellent or good in 8 patients (88.9%). Age > 50 years at primary surgery was a significant risk factor for ASD development, while number of fusion levels, initial diagnosis and type of fusion were not. Conclusion : The incidence of ASD development after lumbar surgery was 11.1% (9 of 81) in this study. Age greater than 50 was the statistically significant risk factor for ASD development. Similar successful clinical outcomes were observed after extended fusion with wide decompression or after interspinous device implantation. Given the latter procedure is less invasive, the findings suggest it may be considered a treatment alternative in selected cases but it needs further study.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.5
• /
• pp.603-609
• /
• 2019

Objective : The purpose of this retrospective study was to determine which of the proximal adjacent segment disease (ASD) and distal ASD was more prevalent and what parameters is more related to ASD in proximal levels and distal levels after more than 2 levels fusions. Methods : The medical records were reviewed retrospectively for 856 cases. A total of 66 cases of ASD were enrolled. On preop magnetic resonance imaging, disc degeneration was measured at the upper and lower parts of surgically treated levels and confirmed by the commonly used Pfirrmann grade. Segmental flexibility in sagittal plane was embodied in segment range of motion (ROM) obtained through flexion and extension X-ray before surgery. Coronal angle was recorded as methods Cobb's angle including fusion levels preoperatively. For the comparison of categorical variables between two independent groups, the chi-square test and Fisher exact test were performed. Results : Proximal ASD and distal ASD were 37/856 (4.32%) and 29/856 (3.39%), respectively. The incidence of proximal ASD was relatively high but insignificant differences. In comparison between ASD group and non ASD group, proximal Pfirmman was higher in proximal ASD and distal Pfirmman was higher in distal ASD group (p=0.005, p<0.008, respectively). However, in the ROM, proximal ROM was higher in proximal ASD, but distal ROM was not different between the two groups (p<0.0001, p=0.995, respectively). Coronal angle was not quite different in both groups (p=0.846). Conclusion : In spite of higher frequency in ASD in proximal level in spinal fusion, it is not clear that incidence of ASD in proximal level is not higher than that of distal ASD group in more than 2 level thoracolumbar fusions. Not only Pfirrmann grade but also proximal segmental ROM is risk factor for predicting the occurrence of ASD in patients more than 2 level of thoracolumbar spine fusion operation excluding L5S1.

• Journal of Korean Neurosurgical Society
• /
• v.46 no.5
• /
• pp.437-442
• /
• 2009

Objective : To characterize perioperative biomechanical changes after thoracic spine surgery. Methods : Fifty-eight patients underwent spinal instrumented fusions and simple laminectomies on the thoracolumbar spine from April 2003 to October 2008. Patients were allocated to three groups; namely, the laminectomy without fusion group (group I, n = 17), the thoracolumbar fusion group (group II, n = 27), and the thoracic spine fusion group (group III, n = 14). Sagittal (ADS) and coronal (ADC) angles for adjacent segments were measured from two disc spaces above lesions at the upper margins, to two disc spaces below lesions at the lower margins. Sagittal (TLS) and coronal (TLC) angles of the thoracolumbar junction were measured from the lower margin of the 11th thoracic vertebra body to the upper margin of the 2nd lumbar vertebra body on plane radiographs. Adjacent segment disc heights and disc signal changes were determined using simple spinal examinations and by magnetic resonance imaging. Clinical outcome indices were determined using a visual analog scale. Results : The three groups demonstrated statistically significant differences in terms of angle changes by ANOVA (p<0.05). All angles in group I showed significantly smaller angles changes than in groups II and III by Turkey's multiple comparison analysis. Coronal Cobb's angles of the thoracolumbar spine (TLC) were not significantly different in the three groups. Conclusion : Postoperative sagittal balance is expected to change in the adjacent and thoracolumbar areas after thoracic spine fusion. However, its prevalence seems to be higher when the thoracolumbar spine is included in instrumented fusion.

• Journal of Korean Medicine Rehabilitation
• /
• v.20 no.2
• /
• pp.1-15
• /
• 2010

Objectives : This study was performed to evaluate the effects of root of Cibotii rhizoma(CR) ethanol extract on the tissue and neuronal damage of the spinal cord injury(SCI). Methods : SCI was induced by mechanical contusion following laminectomy of 10th thoracic vertebra in Sprague-Dawley rats. CR was orally given once a day for 7 days after SCI. Tissue damage and nerve fiber degeneration were examined with cresyl violet and luxol fast blue(LFS) histochemistry. HSP72(as neuronal damage marker), MAP2(as nerve fiber degeneration marker), c-Fos(immediate early gene), and Bax(pro-apoptotic molecule) expressions were examined using immuno-histochemistry. Individual immuno-positive cells expressing HSP72, MAP2, c-Fos and Bax were observed on the damaged level and the upper thoracic and lower lumbar spinal segments. Results : 1. CR reduced degeneration of nerve fibers and motor neuron shrinkage in the ventral horn of the lower lumbar spinal segment, but generally it did not seem to ameliorate the tissue injury following SCI. 2. CR reduced demyelination in the ventral and lateral funiculus of the lower lumbar spinal segment. 3. CR reduced HSP72 expression on the neurons in the peri-central canal gray matter adjacent to the damaged region. 4. CR strengthened MAP2 expression on the motor neurons in the ventral horn and on nerve fibers in the lateral funiculus of the lower lumbar spinal segment. 5. CR reduced c-Fos positive cells in the peri-lesion and the dorsal horn of the damaged level and in the ventral horn of the lower lumbar spinal segment. 6. CR reduced Bax positive cells in the peri-lesion and the dorsal horn of the damaged level and in the ventral horn of the lower lumbar spinal segment. Conclusions : These results suggest that CR plays an inhibitory role against secondary neuronal damage and nerve fiber degeneration. following SCI.