Patterns of short-term and long-term surgical outcomes and prognostic factors for cervical ossification of the posterior longitudinal ligament between anterior cervical corpectomy and fusion and posterior laminoplasty.

To compare short-term and long-term surgical outcome patterns between anterior cervical corpectomy and fusion (ACCF) and laminoplasty (LP) in patients diagnosed with cervical ossification of the posterior longitudinal ligament (OPLL) and identify factors affecting surgical outcomes based on follow-up duration. During short-term follow-up period, surgical outcomes between ACCF and LP were similar. However, there were several reports that long-term surgical outcomes were superior in the ACCF compared with LP. Surgical outcomes between ACCF and LP according to follow-up period changed. This study enrolled 70 patients who underwent ACCF and 63 patients who underwent LP between 2005 and 2012. Patterns of surgical outcomes were analyzed in accordance with surgical procedures. Furthermore, these patients were divided into two subgroups in respect of follow-up duration: the short-term group (less than 48 months) and the long-term group (more than 48 months) group. Occupying ratio, type of OPLL, shape of ossified lesion, cervical sagittal alignment, grade of signal intensity on MRI, and Japanese Orthopedic Association (JOA) score were examined. Surgical outcomes of ACCF went into reverse at 48-month follow-up period. In the short-term group, JOA recovery rate had no difference between ACCF and LP. In the long-term group, the ACCF recovery rate (78.5 ± 31.0) was significantly higher than the LP recovery rate (48.4 ± 54.9) (P = 0.008). In the short-term group, old age (p = 0.011), hill shape (p = 0.013), and high grade of MRI signal intensity (p = 0.040) had negative effects on recovery rate. On the other hand, in the long-term group, LP (p = 0.021) and a high grade of MR signal intensity (p = 0.017) independently and negatively affected recovery rate. Long-term surgical outcomes of ACCF became better than those of LP at more than 48-month follow-up period. High-grade MRI signal changes and the LP surgical procedure were independent negative factors for long-term surgical outcomes in patients with OPLL. Direct decompression of the spinal cord with ACCF provides better long-term stable neurologic outcomes than LP.

Comparison of the Clinical Efficacy of Anabolic Agents and Bisphosphonates in the Patients With Osteoporotic Vertebral Fracture: Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: We investigated the clinical efficacy of anabolic agents compared with bisphosphonates (BPs) for the incidence of new osteoporotic vertebral fracture (OVF) and fracture healing of OVF in the patients with OVF via meta-analyses of randomized controlled trials (RCTs). METHODS: Electronic databases, including PubMed, Embase, and Cochrane Library were searched for published RCTs till December 2022. The RCTs that recruited participants with osteoporosis at high-/very high-risk of fracture (a history of osteoporotic vertebral or hip fracture) or fresh OVF were included in this study. We assessed the risk of bias on every included RCTs, estimated relative risk (RR) for the incidence of new OVF and fracture healing of OVF, and overall certainty of evidence. Meta-analyses were performed by Cochrane review manager (RevMan) ver. 5.3. Cochrane risk of bias 2.0 and GRADEpro/GDT were applied for evaluating methodological quality and overall certainty of evidence, respectively. RESULTS: Five hundred eighteen studies were screened, and finally 6 eligible RCTs were included in the analysis. In the patients with prevalent OVF, anabolic agents significantly reduced the incidence of new OVF (teriparatide and romosozumab vs. alendronate and risedronate [RR, 0.57; 95% confidence interval, 0.45-0.71; p < 0.00001; high-certainty of evidence]; teriparatide vs. risedronate [RR, 0.50; 95% confidence interval, 0.37-0.68; p < 0.0001; high-certainty of evidence]). However, there was no evidence of teriparatide compared to alendronate in fracture healing of OVF (RR, 1.23; 95% confidence interval, 0.95-1.60; p = 0.12; low-certainty of evidence). CONCLUSION: In the patients with prevalent OVF, anabolic agents showed a significant superiority for preventing new OVF than BPs, with no significant evidence for promoting fracture healing of OVF. However, considering small number of RCTs in this study, additional studies with large-scale data are required to obtain more robust evidences.

Factors Associated With Repeat Surgery in Cervical Ossification of the Posterior Longitudinal Ligaments: Minimum 8-year Follow-up Study.

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: The objective of this study is to identify the factors leading to repeat surgery in patients with cervical ossification of the longitudinal ligament (OPLL) during a minimal 8-year follow-up after the initial surgery. SUMMARY OF BACKGROUND DATA: The long-term effects of cervical OPLL are well known, but it's not always clear how many patients need to have surgery again because their neurological symptoms get worse. METHODS: This study is included 117 patients who underwent surgery for cervical OPLL and had a follow-up of at least 8 years. OPLL type, surgical extent, surgical method, and sagittal radiological parameters were measured, and OPLL characteristics were analyzed. RESULTS: The average age of patients at the time of surgery was 53.2 years, with a male-to-female ratio of 78:39. The median follow-up duration was 122 months (96-170 mo). Out of the total, 20 cases (17.1%) necessitated repeat surgery, among which 8 cases required surgery at the same site as the initial operation. The highest rate of repeat surgery was observed in patients who underwent total laminectomy without fusion (TL), where 6 out of 21 patients (29%) needed a second surgery, and 5 of these (23%) involved the same surgical site. Patients who underwent repeat surgery at the same site exhibited a greater range of motion (ROM) one year postsurgery (16.4 ± 8.5° vs. 23.1 ± 12.7°, P =0.041). In addition, the ROM at 1 year was higher in patients who underwent TL compared with those who had laminoplasty. Furthermore, the recurrence rate for hill-shape OPLL was higher at 30.8% compared to 10% for plateau-shape OPLL ( P = 0.05). CONCLUSION: Larger cervical ROM 1 year after surgery is related to repeat surgery at the same level as previous surgery, especially in laminectomy without fusion surgery.

Prognostic Factors of Spinal Intramedullary Hemangioblastoma : Analysis of Surgical Outcomes and Tumor Characteristics.

OBJECTIVE: Spinal intramedullary hemangioblastoma is a rare and highly vascularized benign tumor. The characteristics of the tumor, its corresponding location, and surgical outcomes remain unknown. The purpose of this study was to identify risk factors and strategies for neurologic deterioration following hemangioblastoma surgery. METHODS: A comprehensive retrospective analysis was undertaken to evaluate patients who underwent surgical intervention for intramedullary hemangioblastoma at our institution from 1993 to 2022. Patients with at least 1 year of follow-up data were included. The analysis covered patient demographics, pre- and post-operative modified McCormick scale (MMCS), tumor location, and tumor size. RESULTS: This study included 25 cases. One-year after surgery, neurological deterioration was observed in five cases (20.0%), and neurological improvement was found in nine cases (36.0%). Five cases were ventrally located, and twelve cases were dorsally located. Ventrally located cases were larger in tumor axial size (p=0.029) than dorsal location tumors, resulting in poorer follow-up MMCS and a higher prevalence of von Hippel-Lindau syndrome (VHL) (p=0.042). Three of them were confirmed to be supplied by the anterior spinal artery. In the case of dorsally located cases, there was no neurologic deterioration. CONCLUSION: In intramedullary spinal cord hemangioblastomas, cases located ventrally had a higher incidence of neurological deterioration following surgery than those located dorsally or in intramedullary extramedullary cases. Ventrally located hemangioblastomas were larger than those in other locations. They were mainly supplied by the anterior spinal artery in VHL patients.

Neurenteric cyst of the craniovertebral junction treated to reduce recurrence using different strategies: Two case reports and a literature review.

RATIONALE: Neurenteric cysts are rare benign lesions that are usually located in the lower cervical and upper thoracic spine and extremely rare in the craniovertebral junction. It is generally challenging to completely remove the neurenteric cysts of the craniovertebral junction. We report the cases of 2 patients with neurenteric cyst in the ventral craniovertebral junction managed using different treatment strategies. PATIENT CONCERNS: The first patient was a 64-year-old man. He man was admitted with headache, posterior neck pain, and a tingling sensation in both the forearms. The second patient was a 53-year-old woman. She was admitted with tingling sensations and numbness in both the hands and feet. DIAGNOSES: Cervical spine magnetic resonance imaging showed 2 intradural extramedullary cystic lesions in case 1 and a C2 to C3 intradural extramedullary cystic mass in case 2. INTERVENTIONS AND OUTCOMES: The patient of the case 1 underwent a left C1 to C2 hemi-laminectomy and the cysts were completely removed. Eleven years after the surgery, there was no recurrence. In case 2, we performed a left C2 to C3 hemi-laminectomy and removed only a part of the outer membrane to enable sufficient communication with the surrounding normal subarachnoid space. After removing the cyst wall, the patient underwent C1 to 2 trans articular screw fixation to prevent cervical instability. Ten years after surgery, there was no recurrence of the cyst or new lesions. LESSONS: Clinicians should consider neurenteric cyst in the differential diagnosis of arachnoid cyst or epidermoid cyst. If performing a complete surgical removal is difficult, partial surgical removal, using a cysto-subarachnoid shunt and stabilization, such as screw fixation, could be an alternative treatment option to reduce the risk of mortality and morbidity.

Subsidence Performance of the Bioactive Glass-Ceramic (CaO-SiO2-P2O5-B2O3) Spacer in Terms of Modulus of Elasticity and Contact Area: Mechanical Test and Finite Element Analysis.

OBJECTIVE: The objective of this study is to evaluate the subsidence performance of a bioactive glass-ceramic (CaO-SiO2-P2O5-B2O3) spacer in terms of its modulus of elasticity and contact area using mechanical tests and finite element analysis. METHODS: Three spacer three-dimensional models (Polyether ether ketone [PEEK]-C: PEEK spacer with a small contact area; PEEK-NF: PEEK spacer with a large contact area; and Bioactive glass [BGS]-NF: bioactive glass-ceramic spacer with a large contact area) are constructed and placed between bone blocks for compression analysis. The stress distribution, peak von Mises stress, and reaction force generated in the bone block are predicted by applying a compressive load. Subsidence tests are conducted for three spacer models in accordance with ASTM F2267. Three types of blocks measuring 8, 10, and 15 pounds per cubic foot are used to account for the various bone qualities of patients. A statistical analysis of the results is conducted using a one-way Analysis of variance and post hoc analysis (Tukey's Honestly Significant Difference) by measuring the stiffness and yield load. RESULTS: The stress distribution, peak von Mises stress, and reaction force predicted via the finite element analysis are the highest for PEEK-C, whereas they are similar for PEEK-NF and BGS-NF. Results of mechanical tests show that the stiffness and yield load of PEEK-C are the lowest, whereas those of PEEK-NF and BGS-NF are similar. CONCLUSIONS: The main factor affecting subsidence performance is the contact area. Therefore, bioactive glass-ceramic spacers exhibit a larger contact area and better subsidence performance than conventional spacers.

Development and Validation of an Online Calculator to Predict Proximal Junctional Kyphosis After Adult Spinal Deformity Surgery Using Machine Learning.

OBJECTIVE: Although adult spinal deformity (ASD) surgery aims to restore and maintain alignment, proximal junctional kyphosis (PJK) may occur. While existing scoring systems predict PJK, they predominantly offer a generalized 3-tier risk classification, limiting their utility for nuanced treatment decisions. This study seeks to establish a personalized risk calculator for PJK, aiming to enhance treatment planning precision. METHODS: Patient data for ASD were sourced from the Korean spinal deformity database. PJK was defined a proximal junctional angle (PJA) of ≥ 20° at the final follow-up, or an increase in PJA of ≥ 10° compared to the preoperative values. Multivariable analysis was performed to identify independent variables. Subsequently, 5 machine learning models were created to predict individualized PJK risk post-ASD surgery. The most efficacious model was deployed as an online and interactive calculator. RESULTS: From a pool of 201 patients, 49 (24.4%) exhibited PJK during the follow-up period. Through multivariable analysis, postoperative PJA, body mass index, and deformity type emerged as independent predictors for PJK. When testing machine learning models using study results and previously reported variables as hyperparameters, the random forest model exhibited the highest accuracy, reaching 83%, with an area under the receiver operating characteristics curve of 0.76. This model has been launched as a freely accessible tool at: (https://snuspine.shinyapps.io/PJKafterASD/). CONCLUSION: An online calculator, founded on the random forest model, has been developed to gauge the risk of PJK following ASD surgery. This may be a useful clinical tool for surgeons, allowing them to better predict PJK probabilities and refine subsequent therapeutic strategies.

Vertical split fracture of the vertebral body following oblique lumbar interbody fusion: A case report.

RATIONALE: Oblique lumbar interbody fusion (OLIF) is an effective and safe surgical technique widely used for treating spondylolisthesis; however, its use is controversial because of several associated complications, including endplate injury. We report a rare vertebral body fracture following OLIF in a patient with poor bone quality. PATIENT CONCERNS: A 72-year-old male patient visited our clinic for 2 years with lower back pain, leg radiating pain, and intermittent neurogenic claudication. DIAGNOSES: Lumbar magnetic resonance imaging revealed L4-5 stenosis. INTERVENTION: We performed OLIF with percutaneous pedicle screw fixation and L4 subtotal decompressive laminectomy. We resected the anterior longitudinal ligament partially for anterior column release and inserted a huge cage to maximize segmental lordosis. No complications during and after the operation were observed. Further, the radiating pain and back pain improved, and the patient was discharged. Two weeks after the operation, the patient visited the outpatient department complaining of sudden recurred pain, which occurred while going to the bathroom. Radiography and computed tomography revealed a split fracture of the L5 body and an anterior cage displacement. In revision of OLIF, we removed the dislocated cage and filled the bone cement between the anterior longitudinal ligament and empty disc space. Further, we performed posterior lumbar interbody fusion L4-5, and the screw was extended to S1. OUTCOMES: After the second surgery, back pain and radiating pain in the left leg improved, and he was discharged without complications. LESSON: In this case, owing to insufficient intervertebral space during L4-5 OLIF, a huge cage was used to achieve sufficient segmental lordosis after anterior column release, but a vertebral body coronal fracture occurred. In patients with poor bone quality and less flexibility, a huge cage and over-distraction could cause a vertebral fracture; hence, selecting an appropriate cage or considering a posterior approach is recommended.

Clinical application of bone turnover markers in treating osteoporotic vertebral compression fractures and their role in predicting fracture progression.

This study aimed to investigate whether changes in the bone turnover markers (BTMs) during teriparatide therapy for osteoporotic vertebral compression fractures could reflect therapeutic effects by analyzing the relationship between clinical and radiological features and BTMs. A total of 33 patients with 51 osteoporotic vertebral compression fracture segments were included. Plain radiographs and BTM levels were evaluated at the pretreatment and at 3 months after teriparatide treatment. Based on serial vertebral compression ratio analysis, the progression of fracture was defined as a vertebral compression ratio decrease of ≥10%, relative to the pretreatment values. All segments were divided into 2 groups: the "maintain" group with 32 (62.7%) segments and the "progression" group with 19 (37.3%) segments. After the teriparatide treatment, serum osteocalcin and serum C-terminal telopeptide of type I collagen levels (P = .028 and .008, respectively), and change amounts of them were significantly larger, increasing (P = .001) in the progression group. The vitamin D (25OH-D) levels were significantly lower (P = .038) in the progression group; however, the relative changes in the 25OH-D levels between the 2 groups, before and after the treatment, were not significantly different (P = .077). The parathyroid hormone (PTH) levels were reduced by the teriparatide treatment in both groups, while the decrease in PTH concentration after the treatment was significantly more pronounced in the progression group (P = .006). Significant increase in the osteocalcin and serum C-terminal telopeptide of type I collagen levels and a simultaneous decrease in the PTH levels during the teriparatide treatment suggest that clinicians should assume the progression of fracture.

Influence of subsidence after stand-alone anterior cervical discectomy and fusion in patients with degenerative cervical disease: A long-term follow-up study.

This study aimed to evaluate the influence of subsidence in patients who performed stand-alone anterior cervical discectomy and fusion (ACDF) by analyzing the long-term clinical and radiological outcomes. This retrospective study enrolled 53 patients with 79 segments with degenerative cervical disease treated with stand-alone ACDF with ≥5 years of follow-up. Segmental angle (SA), cervical sagittal alignment (CSA), subsidence, and fusion were analyzed. Visual analog scale (VAS) scores and neck disability index (NDI) were also evaluated. Subsidence occurred in 24 (45.2%) patients and 38 segments (48.1%) at the last follow-up. The mean VAS score and NDI had improved in both the subsidence and non- subsidence groups. The mean SA at the last follow-up had increased to 1.3°â€…±â€…8.5° in the subsidence group and to 1.5°â€…±â€…5.2° in the non-subsidence group compared with the post-operative SA (P < .001). The overall mean CSA at the last follow-up increased over time in both the groups compared with the post-operative CSA (P = .003). The fusion rate at 1 year after surgery was 86.8% and 82.9% in the subsidence and non-subsidence groups, respectively. However, the differences in the SA, CSA, and fusion rates between the groups were not statistically significant (P = .117, .98, and .682, respectively). Subsidence after stand-alone ACDF occurs to a certain capacity; however, it does not appear to significantly influence the radiological and clinical outcomes if foramen decompression is adequately and sufficiently provided in a long-term follow-up study. In contrast, subsidence appears to positively affect the fusion rate in the short-term follow-up.

What Clinicians Should Consider When Performing Oblique Lumbar Interbody Fusion in a Patient with Long Vertebral Body Osteophytes.

OBJECTIVE: Oblique lumbar interbody fusion (OLIF) is known as a minimally invasive technique for disc space augmentation. Motor weakness after OLIF has been known to occur in some cases. This study aimed to report the incidence and potential risk factors for motor weakness following OLIF. METHODS: We enrolled 36 patients and 57 segments who underwent OLIF. Computed tomography was performed before and after OLIF. Clinical data, including age, sex, presenting symptoms, bone mineral density, visual analog scale score, operating segments, and postoperative complications, were collected. We divided the patients into groups with and without neurologic deficit. The disc height was measured and compared between the 2 groups. We also divided the segments into groups with and without neurologic deficit. Foramen height and osteophyte length were measured and compared between the 2 groups. RESULTS: The neurologic deficit group included 3 patients (8%), whereas non-neurologic deficit group included 33 patients (92%). The neurologic deficit group included 5 segments (4%), whereas the non-neurologic deficit group included 109 segments (96%). The disc and foramen heights did not differ significantly between the groups with and without neurologic deficit; however, the osteophyte lengths were longer in the neurologic deficit group. CONCLUSIONS: In our study, vertebral osteophyte length was found to be a potential risk factor for motor weakness after OLIF. For patients with long osteophytes, additional laminectomy following OLIF or another surgical approach for direct decompression should be considered.

Neurologic deficit due to vertebral body osteophytes after oblique lumbar interbody fusion: A case report.

RATIONALE: In recent years, oblique lumbar interbody fusion (OLIF), which uses a window between the peritoneum and the iliopsoas muscle to split the muscle to access the lumbar spine, is known as an effective and safe treatment for spinal diseases, such as degenerative disc disease, spondylolisthesis, recurrent disc herniation, and spinal deformity. Despite this fast and useful surgical method, there were often cases of new neurological symptoms or worsening of symptoms after surgery. We analyzed the preoperative risk factors in a patient with neurologic symptoms, such as motor weakness and exacerbation of radiating pain, after OLIF. PATIENT CONCERNS: A 78-year-old man presented with complaints of numbness in the soles of both feet. L4-5 stenosis was diagnosed on MRI. We performed bilateral L4 laminotomy and L4-5 percutaneous posterior screw fixation after L4-5 OLIF. Postoperatively, his radiating pain improved, and there were no other neurologic symptoms. In the 6th week after surgery, he complained of pain in both ankles, while in the 10th week, the pain progressively worsened, and there was a decrease in motor performance of the right ankle. DIAGNOSIS: Magnetic resonance imaging findings indicated that L4-5 stenosis was resolved. On the basis of the computed tomography findings, the cage was well inserted, the disc height and foramen height increased, and the alignment was good. However, a nerve root injury due to the protruding osteophyte from the inferior endplate of the L4 body was suspected, necessitating exploration of both L4 nerve roots by focusing on the right side. INTERVENTIONS: We performed right facetectomy and right foraminotomy. During surgery, it was confirmed that the right L4 nerve root was entrapped by the osteophyte. OUTCOMES: Postoperatively, his radiating pain improved, and motor performance of his right ankle was restored. LESSONS: A prominently protruding osteophyte is assessed as a possible risk factor for the development of new neurologic deficits after OLIF. In patients with confirmed osteophytes, surgery should be planned taking into consideration the shape of the osteophytes and their relationship to the nerve root.

Thoracolumbar Slope Is Useful Parameter for Evaluating HealthRelated Quality of Life and Sagittal Imbalance Aggravation in Adult Spinal Deformity: A Prospective Observational Cohort Study.

OBJECTIVE: The purpose of the present study was to evaluate the natural course of primary degenerative sagittal imbalance (PDSI), its aggravating factors, and health-related quality of life (HRQoL) associated with various spinal alignment parameters (SAPs) in patients with PDSI who have not undergone surgery. METHODS: One hundred three participants volunteered to participate. The SAPs, including T1 pelvic angle (T1PA), thoracolumbar tilt, and thoracolumbar slope (TLS), were measured on whole-spine standing radiographs. The back and lumbar muscle volumes were measured. To determine HRQoL at baseline and at 2-year follow-up, face-to-face questionnaires were administered, which included visual analogue scale of the back and leg, physical component summary/mental component summary of 36-item Short Form Health Survey, Oswestry Disability Index (ODI), and Mini-Mental State Examination. RESULTS: Overall HRQoL measures had improved after 2 years of follow-up compared to baseline. PDSI aggravation was observed in 18 participants (26.1%). TLS, sagittal vertical axis (SVA), and T1PA were strongly correlated with each other. TLS, SVA, and T1PA were correlated with ODI score. Among them, TLS was most highly correlated with ODI score. TLS greater than -3.5° was a predicting factor for PDSI aggravation (p = 0.034; 95% confidence interval, 1.173-63.61; odds ratio, 8.636). CONCLUSION: The present study implied that PDSI does not necessarily worsen with aging. TLS is an appropriate parameter for assessing the clinical situation in patients with PDSI. Furthermore, a TLS greater than -3.5° predicts PDSI aggravation; thus, TLS may be a useful parameter for predicting prognosis in PDSI.

Risks and benefits of timely screw removal after thoracolumbar spine fractures treated with non-fusion technique.

BACKGROUND: Percutaneous-short segment screw fixation (SSSF) without bone fusion has proven to be a safe and effective modality for thoracolumbar spine fractures (TLSFs). When fracture consolidation is confirmed, pedicle screws are no longer essential, but clear indications for screw removal following fracture consolidation have not been established. METHODS: In total, we enrolled 31 patients with TLSFs who underwent screw removal following treatment using percutaneous-SSSF without fusion. Plain radiographs, taken at different intervals, measured local kyphosis using Cobb' angle (CA), vertebra body height (VBH), and the segmental motion angle (SMA). A visual analogue scale (VAS) and the Oswestry disability index (ODI) were applied pre-screw removal and at the last follow-up. RESULTS: The overall mean CA deteriorated by 1.58° (p < 0.05) and the overall mean VBH decreased by 0.52 mm (p = 0.001). SMA preservation was achieved in 18 patients (58.1%) and kyphotic recurrence occurred in 4 patients (12.9%). SMA preservation was statistically significant in patients who underwent screw removal within 12 months following the primary operation (p = 0.002). Kyphotic recurrence occurred in patients with a CA ≥ 20° at injury (p < 0.001) with a median interval of 16.5 months after screw removal. No patients reported worsening pain or an increased ODI score after screw removal. CONCLUSION: Screw removal within 12 months can be recommended for restoration of SMA with improvement in clinical outcomes. Although, TLSFs with CA ≥ 20° at the time of injury can help to predict kyphotic recurrence after screw removal, the clinical outcomes are less relevant.

Clinical, Radiographic, and Genetic Analyses in a Population-Based Cohort of Adult Spinal Deformity in the Older Population.

OBJECTIVE: This study aimed to identify the sagittal parameters associated with health-related quality of life and genetic variations that increase the risk of adult spinal deformity (ASD) onset in the older population. METHODS: We recruited 120 participants who had a sagittal vertical axis > 50 mm in a sagittal imbalance study. Sagittal radiographic parameters, cross-sectional area, and intramuscular fatty infiltration using the Goutallier classification in the paraspinal lumbar muscles were evaluated. Functional scales included the self-reported Oswestry Disability Index (ODI), 36-item Short Form Health Survey (SF-36), and visual analogue scales (VAS) for back and leg pain. We performed whole-exome sequencing and an exome-wide association study using the 100 control subjects and 63 individuals with severe phenotypes of sagittal imbalance. RESULTS: Pelvic incidence minus lumbar lordosis (PI-LL) mismatch was negatively associated with the SF-36 and positively correlated with ODI and VAS for back and leg pain. PI-LL was related to the quality and size of the paraspinal muscles, especially the multifidus muscle. We identified common individual variants that reached exome-wide significance using single-variant analysis. The most significant single-nucleotide polymorphism was rs78773460, situated in an exon of the SVIL gene (odds ratio, 9.61; p = 1.15 × 10-9). CONCLUSION: Older age, higher body mass index, and a more significant PI-LL mismatch were associated with unfavorable results on functional scales. We found a genetic variation in the SVIL gene, which has been associated with the integrity of the cytoskeleton and the development of skeletal muscles, in severe ASD phenotypes. Our results help to elucidate the pathogenesis of ASD.

Acute transverse myelitis following scrub typhus: A case report and review of the literature.

Context: Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi. The disease can usually involve the lungs, heart, liver, spleen and brain through hematogenous dissemination. However, very rarely, acute transverse myelitis in the spinal cord develops from scrub typhus. We present a case of acute transverse myelitis following scrub typhus with a review of the literature. Findings: A 66-year-old male visited a hospital for general myalgia, mild headache, and fever in October. He was noted to have thick, black papule skin on his abdomen, which was highly suggestive of scrub typhus. To confirm the diagnosis, O. tsutsugamushi antibody titers were examined and detected highly in serum by an indirect fluorescence antibody assay. Doxycycline, the standard treatment for scrub typhus, was administered. However, after seven days of treatment, he rapidly developed weakness in the right leg, paresthesia in both lower limbs, and voiding difficulty. Spinal magnetic resonance imaging (MRI) revealed lesions with high signal intensity involving the spinal cord at the thoracolumbar junction. Paraparesis gradually improved following steroid pulse therapy for five days. At one-year follow-up, he could walk without cane. Conclusions:Orientia tsutsugamushi causes scrub typhus, which can affect not only the brain, but also the spinal cord. Although acute transverse myelitis develops rarely from scrub typhus, this should be considered as differential diagnosis in patients of fever with neurological deficit in endemic areas.

Unexpected Intradural Lumbar Disk Herniation Found During Transforaminal Endoscopic Surgery.

BACKGROUND: Intradural disk herniation (IDH) is defined as the displacement of the intervertebral disk nucleus pulposus into the dural sac. In this lumbar lesion, the affected level differs from that of a traditional extradural herniation: 55% of cases occur at the level of L4-5, 16% at L3-4, and 10% at L5-S1. Upper lumbar IDH is extremely rare. We present a case of an IDH at the level of L2-3 that was diagnosed during endoscopic surgery. CASE DESCRIPTION: A 65-year-old male patient presented with severe radiating pain in the anterior right thigh that was accompanied by a tingling sensation in the right calf and difficulty in walking. Physical examination showed normal strength. Bladder and bowel function was normal, but mild hypesthesia of the L3 sensory dermatome was observed. Magnetic resonance imaging revealed a herniated disk at the level of L2-L3 that was compressing the right side of the dura. A percutaneous transforaminal endoscopic lumbar diskectomy was planned. After foraminoplasty, no ruptured disk fragments could be found. During dissection of the adhesion between the dura and protruded disk, the dura was torn. Interestingly, through this dural opening, multiple fragmented disk portions were visualized among the nerve rootlets. We removed some of the soft disk material; however, complete removal of the disk fragments was predicted to damage the rootlets, and we decided to convert to microscopic surgery. The disk fragments were successfully removed via durotomy under microscopic assistance. The incised dorsal dura was primarily sutured with continuous stitches, and the defect on the ventrolateral side of the dura was patched and sealed using a harvested inner ligamentum flavum and Gelfoam (Pfizer, New York, New York, USA). After the operation, the patient's symptoms improved. There was no cerebrospinal fluid leakage. CONCLUSIONS: If there is any preoperative clinical or radiologic suspicion of IDH, a microscopic surgical approach should be considered to be the first-line option, as this is a safe and effective method for achieving IDH removal and dura repair without a postoperative neurologic deficit. Even during endoscopic surgery, if the surgeon expects even minor complications, we suggest converting to open surgery. In addition, the adequate sealing of the dura may be sufficient to prevent cerebrospinal fluid leakage, without the need for dural suture and lumbar drainage.

Is the Agricultural Work a Risk Factor for Koreans Elderly Spinal Sagittal Imbalance?

OBJECTIVE: A primary degenerative sagittal imbalance has been considered because of unique lifestyles such as the prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Previous papers have reported that sagittal imbalance disease is often seen distinctly in the farming districts of "oriental" countries such as Korea and Japan. However, this finding was only evaluated with the use of X-ray, and other factors such as magnetic resonance imaging (MRI), muscle volume, compression fracture, and laboratory results were not considered. Thus, using these, we evaluate the agricultural work-associated factors for Korean elderly spinal sagittal imbalance. METHODS: We recruited 103 Korean participants who had a sagittal vertical axis (SVA) of >5 cm in this Korean Elderly Sagittal Imbalance Cohort Study. The following were evaluated : radiological parameters, MRI, compression fracture, vitamin D, parathyroid hormone, C-terminal telopeptide, osteocalcin, bone mineral density and muscle fatty change, muscle volume, and health-related quality of life from patients' survey. Moreover, in this survey, the farmers' annual working hours were investigated. Subsequently, we analyzed the associated factors for spinal sagittal imbalance depending on occupation. RESULTS: A total of 46 participants were farmers, and the others were housewives, sellers, and office workers. The farmer group had more SVA (141 vs. 99 mm, p=0.001) and pelvic tilt (31° vs. 24°, p=0.004) and lesser lumbar lordosis (20° vs. 30°, p=0.009) and thoracic kyphosis (24° vs. 33°, p=0.03) than non-farmer group. A significantly positive correlation was noted between the working hour and SVA in the farmer group (p=0.014). The visual analogue scale score for back pain (8.26 vs. 6.96, p=0.008) and Oswestry Disability Index (23.5 vs. 19.1, p=0.003) in the farmer group were higher than that in the non-farmer group, but the Short Form-36 score was not significantly different between the two groups. The Mini-Mental State Exam score was significantly lower in the farmer group than in the non-farmer group (24.85 vs. 26.98, p=0.002). CONCLUSION: The farmer group had more sagittal imbalance and back pain in proportion to the working hours even though the muscle and bone factors and general laboratory condition were not significantly different between the two groups. These results supported that the long hours spent in the crouched posture while performing agricultural work were a risk factor for severe sagittal imbalance.

Outcomes of Patients Undergoing Anterior Screw Fixation for Odontoid Fracture and Analysis of the Predictive Factors for Surgical Failure.

OBJECTIVE: Anterior odontoid screw fixation (AOSF) is a safe and effective treatment for type II and rostral type III odontoid fracture. This study aimed to report the outcomes of the AOSF surgery and evaluate the potential risk factors of surgical failure. METHODS: We enrolled 63 patients who underwent AOSF. Follow-up computed tomography was performed 6 months after the surgery and once a year thereafter to evaluate the union. Clinical data including the age, sex, presenting symptoms, cause of injury, fracture gaps, dislocation position, degree of displacement, screw direction angle, and time interval from injury to operation were collected. RESULTS: Successful fusion was achieved in 55 patients (87.3%) and surgical failure occurred in 8 patients (12.7%). Variables such as age, sex, dislocation position, degree of displacement, screw direction angle, and time interval from injury to operation were not significantly associated with the surgical failure. However, surgical failure was statistically significantly associated with the fracture gap. The overall mean fracture gap at the time of injury was 1.29 mm (range, 0-3.11 mm), and the incidence of surgical failure was 8.3 times higher when the fracture gap at the time of injury was > 2 mm (p = 0.019). CONCLUSION: When performing AOSF in patients with type II or rostral shallow type III odontoid fractures, the displacement of the odontoid fracture fragment should be appropriately reduced to the aligning position before screw insertion and downward reduction should be achieved by perforation of the apical cortex of the odontoid during screw fixation, even if the surgery is delayed.

Single-Stage Posterior Circumferential Stabilization Using Double Small Cages for the Treatment of Thoracic and Lumbar Spine Fractures.

OBJECTIVE: Controversy remains regarding the optimal methods for resection of the vertebral body, reconstruction of the anterior column, and decompression of the spinal cord in patients who have severe vertebral body destruction of the thoracic or lumbar spine with associated neurologic impairment. We report an alternative technique for primary treatment and salvage involving single-stage corpectomy followed by reconstruction of the anterior column using double small mesh cages via the posterior-only approach. METHODS: Plain radiographs and computed tomography scans, taken at different intervals, were used to measure local kyphosis, segmental height, and fusion grade. Pain was evaluated using the visual analog scale (VAS), and neurologic symptoms were classified according to Frankel grade. RESULTS: The mean kyphotic deformity improved by 14.47 ± 9.06 degrees (P < 0.001), and the mean segmental height improved by 7.17 mm ± 6.11 mm (P < 0.001) after surgery. Fusion was achieved at 84% of patients, within a median interval of 12 months. Kyphotic recurrence was observed in 2 patients (11%), segmental height loss occurred in 1 patient (5%), and both kyphotic recurrence and segmental height loss occurred in 1 patient (5%). None of the patients reported worsening pain or neurologic symptoms after surgery, and there were no surgery-related complications such as neural injury, cerebrospinal fluid leakage, cage dislocation, surgical site infection, or cardiopulmonary complications. CONCLUSIONS: Single-stage corpectomy followed by reconstruction of the anterior column using double small mesh cages via the posterior-only approach is a reliable and less invasive single-stage treatment and salvage option in selected cases.