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Study design: Retrospective study. Objectives: To evaluate changes in the adjacent segment after posterior instrumentation and fusion in thoracolumbar spinal fractures. Summary of Literature Review: The incidence of adjacent-segment disease is increasing as spinal surgery becomes more common. Many studies have been conducted on the risk factors for adjacent-segment changes in the lumbar spine, but few articles have been published on this topic in the thoracolumbar spine. Material and Methods: The records of 50 patients who received treatment from 2000 to 2013 were reviewed retrospectively. They underwent posterior instrumentation and fusion due to thoracolumbar fracture and were followed up for more than 2 years. To evaluate changes in the adjacent segment, immediate postoperative and last follow-up values of the sagittal angle, disc height, and disc angle were compared between groups divided by age (more or less than 50 years), laminectomy, and fusion levels. The Pfirrmann grade of the discs proximal and distal to the fusion level was also measured using preoperative magnetic resonance imaging. Results: Thirty-six patients were male and 14 were female. The average age of the 50 patients was 45.6 years, and the mean follow-up period was 4.3 years. There were no cases of adjacent-segment disease. The mean kyphotic sagittal angle progression was 6.8° (range, −11° to 28.5°, p=0.000). The mean change of disc height of the proximal adjacent segment was 0.3 mm (range, −1.6 to 3.4 mm, p=0.013) and 0.6 mm (range, −4.1 to 5.8 mm, p=0.013) in the distal adjacent segment. Laminectomy did not make a significant difference. In the group below 50 years of age, the angle of the adjacent segment discs increased by 0.8° (range, −3.1° to 5.1°, p=0.004) at the proximal adjacent segment and by 0.5°(range, −4.8° to 2.9°, p=0.016) at the distal adjacent segment. Proximal adjacent disc height decreased as the fusion levels increased. As the preoperative Pfirrmann grade increased, degenerative changes in the proximal adjacent segment disc tended to accelerate. Conclusions: Adjacent-segment disease after lumbar fusion surgery was not found in adjacent segments of the thoracolumbar spine. This seems to be due to the anatomical characteristics of the lumbar spine, which is more flexible than the thoracolumbar vertebra. The mobile segments of the lumbar spine may account for this difference, rather than the instrumentation and fusion procedure itself.

Study Design: Retrospective study. Objectives: To analyze the outcomes of degenerative lumbar spine surgery in patients undergoing hemodialysis due to chronic kidney disease (CKD). Summary of Literature Review: Patients who undergo hemodialysis due to chronic renal disease tend to exhibit accelerated changes in bone quality, deterioration of spinal stenosis, and accompanying neurological degeneration. The surgical treatment of chronic spinal diseases is also becoming more necessary with the increased lifespan of these patients. Materials and Methods: We reviewed the medical records and radiographs of patients with CKD undergoing hemodialysis who were followed-up for more than 1 year after posterior lumbar spinal surgery. We evaluated clinical, laboratory, and radiologic variables. For a comparative analysis, patients were classified into subgroups according to age (65 years old), duration of hemodialysis (10 years), and type of surgery (simple decompression or fusion). Results: We included 21 patients (5 men, 16 women) with a mean age of 66.2 years (range, 48-87 years). The mean duration of hemodialysis and follow-up was 18.9 years and 43 months, respectively. Decompressions with fusion were performed in 11 patients and simple decompressions in the other 10. The mean visual analog scale (VAS) of leg pain and the Oswestry Disability Index (ODI) significantly improved after surgery at time of the last follow-up; meanwhile, the mean VAS score for lower back pain did not show a statistically significant improvement. The postoperative ODI was correlated with age (correlation coefficient=0.71, p=0.006). In patients less than 65 years old, the ODI improvement was greater (p=0.035) than in those 65 years of age or older. There was no significant difference in the clinical outcomes according to the duration of hemodialysis. Complications were observed in 11 patients (52.4%, 7 in fusion and 4 in simple decompression), of which 2 cases were infections, and reoperations were performed in 5 patients. The union rate of the fusion cases at the 1-year follow-up was 81.8%. Conclusions: Appropriate spine surgery improved radicular pain and the ODI in patients with degenerative lumbar disease undergoing hemodialysis. However, postoperative complications were frequent and the improvement of clinical outcomes was minimal, especially in patients over 65 years of age and in those who underwent fusion. Therefore, the surgical treatment of patients with chronic renal disease undergoing hemodialysis requires adequate consideration of age and the duration of hemodialysis.

Study Design: Case-control study (retrospective comparative study). Objectives: The purpose of this study was to define the relationship between low back pain (LBP) and the cross-sectional area (CSA) and density of the erector spinae muscle (ESM) and isolated multifidus muscle (IMM) on computed tomography (CT) scans of patients with a chief complaint other than LBP. Summary of Literature Review: Most previous studies have focused on radiographic data from patients with a chief complaint of LBP, rather than on radiographic data from patients with a chief complaint other than LBP. Material and Methods: This retrospective study included 475 patients who underwent CT scans between January 1, 2010 and December 31, 2010. The CSA and density of the ESM, IMM, and the psoas muscle (PM) were obtained. All measurements were calculated as the ratio of each muscle. The relationships between the CSA of each muscle and both types of LBP were analyzed. Results: The ESM-to-PM ratio in terms of density was 1.227±0.797 in the LBP group and 0.645±0.732 in the non-LBP group (p=0.174). The IMM-to-PM ratio in terms of density was 0.664±0.515 in the LBP group and 0.806±0.518 in the non-LBP group (p=0.007). Conclusions: The IMM was more relevant to LBP than the ESM of the back, and density was more relevant to LBP than the CSA of regular muscles. The IMM was more useful than the ESM for analyzing LBP.

Study Design: Research using radiographic findings. Objectives: To compare spinopelvic parameters in detail between normal subjects and those who had bilateral gonarthrosis with or without spondylosis. Summary of Literature Review: The relationship between knee joint flexion contracture and hypolordosis in the lumbar spine has been well established. However, spinopelvic parameters in subjects with gonarthrosis without flexion contracture have not been well described in the literature. Materials and Methods: Fifty-seven male subjects in their 60s with bilateral gonarthrosis over Kellgren-Lawrence grade III were included. They were subdivided into the KS group (with spinal osteoarthritis, n=32) and the KN group (without spinal osteoarthritis, n=25). Normal asymptomatic subjects without disease in their back or leg were analyzed as the control group (NN; n=84). The following spinopelvic parameters were measured and compared; C7 plumbline (C7PL), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). Results: In the KS group, the C7PL was significantly anteriorly displaced compared to the KN group (1.7±4.5 cm vs. −0.6±2.9 cm, p=0.031) and the NN group (1.7±4.5 cm vs. −0.5±2.9 cm, p=0.014). TK in the KN group was significantly smaller than in the NN group (25.4±8.8° vs. 30.1±8.3°, p=0.041). The KS group had the smallest value of LL, while the NN group had the largest value of LL (−23.2±48.7° vs. −44.9±33.8° vs. −57.3±8.5°, p<0.001). No significant difference was observed in PI, SS, or PT among the 3 groups. A strong correlation was found between LL and SS in the NN group (R=−0.776, p<0.01), while this correlation was moderate in the KN group (R=−0.355, p<0.01). Conclusions: Overall balance was maintained in the subjects who had gonarthrosis without spinal osteoarthritis. Subjects with gonarthrosis showed less LL, especially if they had spinal osteoarthritis. Further studies are needed to characterize the differences in these pelvic parameters, and to evaluate changes in individuals with knee joint flexion contracture.

Study Design: Retrospective analysis. Objectives: To determine the relationship between pelvic tilt and lumbar disc degeneration. Summary of Literature Review: The shape and the spatial orientation of the pelvis determine the organization of the lumbothoracic spine. The purpose of our study was to determine the relationship between pelvic tilt and lumbar disc degeneration. Materials and Methods: Sixty patients over 50 years of age who had undergone lumbar spine magnetic resonance imaging were recruited. In individuals between 41 and 60 years of age, the normal pelvic tilt is 14°. Patients were divided into a low pelvic tilt (PT) group (<14°) and a high pelvic tilt (PT) group (≥14°). Lumbar disc degeneration was graded from I to V according to the Pfirrmann grade. We defined grades IV and V as high-grade degeneration and the others as low-grade degeneration. Radiologic parameters and lumbar disc degeneration were compared between these 2 groups. Results: In the low PT group, the average degeneration grade of each lumbar segment was 2.61 in L1-L2, 2.61 in L2-L3, 3.00 in L3-L4, 3.39 in L4-L5, and 3.84 in L5-S1. The corresponding grades in the high PT group were 2.34 in L1-L2, 2.62 in L2-L3, 3.07 in L3-L4, 3.76 in L4-L5, and 3.55 in L5-S1. The grade of degeneration of the high PT group was significantly higher than that of the low PT group for L4-L5 (p=0.031). High-grade degeneration of the L4-L5 segment was significantly more common in the high PT group (odds ratio=4.65; 95% CI, 1.406-15.381; p=0.012). Conclusions: Patients with high pelvic tilt had a higher grade of lumbar disc degeneration in the L4-L5 segment regardless of age or gender.

Study Design: Retrospective study. Objectives: To evaluate the outcomes of dual growing rod treatment over a follow-up period of at least 2 years in patients with progressive pediatric spinal deformity. Summary of Literature Review: The dual growing rod treatment is safe and effective in curve correction and maintenance in patients with progressive pediatric spinal deformity. Materials and Methods: Between 2009 to 2017, 14 patients who underwent dual growing rod treatment were followed up for more than 2 years. We analyzed their demographic and radiologic data, including age at surgery, sex, diagnosis, instrumented levels, number of total operations, number of lengthening procedures, interval of lengthening, Cobb angle, thoracic kyphosis angle, lumbar lordosis angle, T1-S1 length, and complications. Results: The mean age of the patients was 11.0±2.9 years old. There were 10 male and 4 female patients, including 8 cases of neuromuscular scoliosis, 3 cases of idiopathic scoliosis, 2 cases of spondyloepiphyseal dysplasia, and 1 case of congenital scoliosis. The mean follow-up period was 42.4±14.0 months. The total number of operations was 6.6±2.6. The average number of lengthening procedures was 4.3±2.3 at an interval of 6.9±2.1 months. The Cobb angle improved from 60.4°±27.9° to 33.5°±19.7° after the initial treatment and 29.1°±16.4° after the last follow-up or final fusion. The T1-S1 length increased from 328.2±57.5 mm to 388.0±64.9 mm after the initial treatment and 424.9±64.4 mm after the last follow-up or final spinal fusion. The average growth rate was 11.5 mm/year. Six patients experienced 11 complications, of which 4 were Implant-related, and 7 were Infections. Conclusions: The dual growing rod technique is an effective and relatively safe treatment in patients with progressive pediatric spinal deformity.

Study Design: Retrospective analysis Objectives: Loss of fracture reduction after posterior surgery to treat unstable thoracolumbar fractures can cause several complications. We analyzed the factors influencing postoperative loss of reduction. Summary of Literature Review: Controversy exists about the factors causing postoperative loss of reduction in thoracolumbar fractures during the follow-up period. Materials and Methods: We analyzed the records of 59 patients who underwent posterior surgery for thoracolumbar unstable fractures and had completed a minimum follow-up of 1 year. Postoperative loss of reduction was defined as 30% or more loss of vertebral body height or 15° or more progression of the kyphotic angle at the 1-year follow-up compared to immediately after surgery. The associations between the patients’ gender, age, level of fracture, injury of the posterior column, initial loss of fractured vertebral body height, loadsharing score, Thoraco-Lumbar Injury Classification and Severity score, number of fixed segments, type of pedicle screws, degree of postoperative reduction, degree of postoperative corrected kyphotic angle, changes in the insertion angle of the most proximal and the most distal pedicle screws, decreases in the upper and lower disc height of the fractured vertebral body, and postoperative loss of reduction were analyzed. Results: Thirteen patients (22.0%) had postoperative loss of reduction. Age at the time of the operation (p=0.034), initial loss of fractured vertebral body height (p=0.042), and changes in the insertion angles of the most distal pedicle screws (p=0.021) were significantly associated with postoperative loss of reduction. However, the other factors did not show a significant relationship. Conclusions: In patients who underwent posterior surgery for unstable thoracolumbar fractures, the frequency of loss of reduction was high in patients more than 45 years old at the time of the operation, with a 50% or more loss of the initial fractured vertebral body height, and with changes of 5° or more in the insertion angles of the most distal pedicle screws.

Study Design: Case report Objectives: This study introduces an interesting case of adolescent cervical myelopathy with atypical cervical magnetic resonance imaging (MRI) findings. A differential diagnosis was made, followed by successful surgical treatment. Summary of Literature Review: A careful differential diagnosis of high signal intensity on T2-weighted cervical MRI is necessary if there is no evidence of cervical stenosis. Recent reports have suggested that the differential diagnosis should be based on a comprehensive analysis of data, including brain MRI, a cerebrospinal fluid examination, and empirical steroid treatment. Materials and Methods: A 17-year-old male patient complained of upper extremity weakness, gait disturbance, and decreased sensation in the upper extremity. Cervical spine MRI findings suggested C3/4 disc herniation, moderate cervical stenosis, and high signal intensity in the spinal cord. A differential diagnosis was made between cervical myelopathy and myelitis. Results: Decompression and posterolateral fusion of C3/4 were performed in a 17-year-old patient with cervical myelopathy without significant cervical stenosis. Postoperatively, upper extremity sensation and weakness and gait disturbance showed improvement, and the Japanese Orthopedic Association score improved to 17 points at 6 months after surgery. Conclusions: In patients with cervical myelopathy showing high signal intensity on T2-weighted imaging without evident spinal stenosis, a differential diagnosis should be made between cervical myelopathy and myelitis; surgical decompression can be an effective treatment choice upon the diagnosis of cervical myelopathy.