Generation of synthetic PET/MR fusion images from MR images using a combination of generative adversarial networks and conditional denoising diffusion probabilistic models based on simultaneous 18F-FDG PET/MR image data of pyogenic spondylodiscitis.

BACKGROUND CONTEXT: Cross-modality image generation from magnetic resonance (MR) to positron emission tomography (PET) using the generative model can be expected to have complementary effects by addressing the limitations and maximizing the advantages inherent in each modality. PURPOSE: This study aims to generate synthetic PET/MR fusion images from MR images using a combination of generative adversarial networks (GANs) and conditional denoising diffusion probabilistic models (cDDPMs) based on simultaneous 18F-fluorodeoxyglucose (18F-FDG) PET/MR image data. STUDY DESIGN: Retrospective study with prospectively collected clinical and radiological data. PATIENT SAMPLE: This study included 94 patients (60 men and 34 women) with thoraco-lumbar pyogenic spondylodiscitis (PSD) from February 2017 to January 2020 in a single tertiary institution. OUTCOME MEASURES: Quantitative and qualitative image similarity were analyzed between the real and synthetic PET/ T2-weighted fat saturation MR (T2FS) fusion images on the test data set. METHODS: We used paired spinal sagittal T2FS and PET/T2FS fusion images of simultaneous 18F-FDG PET/MR imaging examination in patients with PSD, which were employed to generate synthetic PET/T2FS fusion images from T2FS images using a combination of Pix2Pix (U-Net generator + Least Squares GANs discriminator) and cDDPMs algorithms. In the analyses of image similarity between the real and synthetic PET/T2FS fusion images, we adopted the values of mean peak signal to noise ratio (PSNR), mean structural similarity measurement (SSIM), mean absolute error (MAE), and mean squared error (MSE) for quantitative analysis, while the discrimination accuracy by three spine surgeons was applied for qualitative analysis. RESULTS: Total of 2,082 pairs of T2FS and PET/T2FS fusion images were obtained from 172 examinations on 94 patients, which were randomly assigned to training, validation, and test data sets in 8:1:1 ratio (1664, 209, and 209 pairs). The quantitative analysis revealed PSNR of 30.634 ± 3.437, SSIM of 0.910 ± 0.067, MAE of 0.017 ± 0.008, and MSE of 0.001 ± 0.001, respectively. The values of PSNR, MAE, and MSE significantly decreased as FDG uptake increased in real PET/T2FS fusion image, with no significant correlation on SSIM. In the qualitative analysis, the overall discrimination accuracy between real and synthetic PET/T2FS fusion images was 47.4%. CONCLUSIONS: The combination of Pix2Pix and cDDPMs demonstrated the potential for cross-modal image generation from MR to PET images, with reliable quantitative and qualitative image similarities.

Comparison of radiological and functional outcomes of conservative treatment with teriparatide and denosumab in thoracolumbar osteoporotic vertebral fracture.

Teriparatide and denosumab, anti-osteoporosis medications with different mechanisms, have been widely used in the patients with osteoporotic vertebral fracture (OVF) considered as advanced osteoporosis. Teriparatide has been shown to enhance bone formation and fracture healing in OVF, but there are still no sufficient evidences discussing about the role of denosumab in newly developed OVF. In this study, we found the similar radiological deformation and functional outcomes of conservative treatment with teriparatide and denosumab in thoracolumbar (TL) OVF, and teriparatide showed a more frequent incidence of fracture union with paravertebral bone bridge formation compared to denosumab. INTRODUCTION: Teriparatide and denosumab have been widely used to treat advanced osteoporosis and prevent subsequent fractures in patients with OVCF. Unlike teriparatide, which is considered to be effective in fracture healing, there is still no clear role and evidence for the effect of denosumab in acute OVCF. This study compared the radiological and functional outcomes of conservative treatment with teriparatide and denosumab in TL-OVF. METHODS: This retrospective study enrolled 78 women with mean age of 74.69 ± 7.66 (60-92) years diagnosed as a TL-OVF with no neurological deficits. All patients were treated conservatively with teriparatide (34 of group T, once-daily 20 µg) or denosumab (44 of group D, once-6 months 60 mg) for 6 months. We evaluated the radiological deformation (kyphotic angle, segmental vertebral kyphotic angle, and compression ratio) and the incidence of fracture union with paravertebral bone bridge formation (FUPB) and functional outcomes using the visual analog scale (VAS) and Oswestry Disability Index (ODI) at 0, 3, and 6 months. RESULTS: In the radiological deformation and functional outcomes, there were no significant differences at 0, 3, and 6 months between the two groups (P > 0.05). However, the incidence of FUPB at 6 months was higher in group T (20/34, 58.8%) compared to group D (11/44, 25.0%) (P = 0.004), and teriparatide was the most statistically significant factor for achieving FUPB (OR 4.486, P = 0.012) in multivariable logistic analysis. CONCLUSIONS: Teriparatide and denosumab, despite of their different pharmacological mechanisms, showed similar radiological deformation and functional outcomes in the conservative treatment of TL-OVF. However, teriparatide showed a significantly higher incidence of fracture union with paravertebral bone bridge formation.

Diagnostic and prognostic significance of preoperative evoked potential tests in degenerative cervical myelopathy.

BACKGROUND CONTEXT: Decompression surgery is a treatment option for patients with degenerative cervical myelopathy (DCM). Surgical decisions primarily depend on clinical symptoms and radiological examinations. The diagnostic and prognostic significance of evoked potential tests for surgical outcomes in patients with DCM has not been thoroughly examined. PURPOSE: To identify the diagnostic and prognostic significance of preoperative evoked potential tests in patients with DCM who underwent decompression surgery. STUDY DESIGN: This was a retrospective observational study. PATIENT SAMPLE: One hundred two consecutive patients who underwent evoked potential tests and surgical treatment between January 2016 and December 2020 in a single spine center and had a minimum follow-up of 6 months. OUTCOME MEASURES: Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery. METHODS: This study evaluated the preoperative central motor conduction time (CMCT), somatosensory evoked potentials, and Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery. RESULTS: Abnormal CMCT findings were observed in 94 patients (92.2%). Abnormal somatosensory evoked potentials were observed in 77 patients (75.5%). There was a statistically significant correlation between preoperative JOA score and abductor pollicis brevis (APB)-CMCT (r=-0.546, p=.001), tibialis anterior (TA)-CMCT (r=-0.517, p<.001), median nerve (MN)-SSEP (r=-0.353, p=.001), and tibial nerve (TN)-SSEP (r=-0.349, p=.003). There were significant differences in recovery rates associated with diabetes mellitus (DM), preoperative severity of myelopathy, TA-CMCT, MN-SSEP, and TN-SSEP. Stepwise multiple regression analysis showed that the major factors affecting the clinical outcomes were TN-SSEP (ß=0.327, p=.004), preoperative JOA score (ß=0.278, p=.012), and DM (ß=0.241, p=.025). CONCLUSIONS: Evoked potential testing is a functional diagnostic tool that can indicate the severity of myelopathic symptoms in patients with DCM. Additionally, preoperative TN-SSEP may have significant prognostic value in predicting postoperative clinical outcomes. Thus, preoperative evoked potential tests could be helpful for determining suitable surgical treatment candidates and forecasting postoperative prognosis.

Analysis of Clinical Factors Associated with Medical Burden and Functional Status in Pyogenic Spine Infection.

BACKGROUND AND PURPOSE: Pyogenic spinal infection (PSI) has recently been on the rise due to aging and increasing degenerative spinal disease related procedures. PSI requires long-term antibiotic treatment and is followed by sustained functional disability even after successful treatment. This study aimed to analyze the clinical factors associated with medical burden and functional status of PSI. METHODS: This retrospective study involved patients with non-postoperative PSI of thoraco-lumbo-sacral area in a single tertiary hospital. The length/cost of hospitalization with an antibiotic therapy and severity of back pain using the short form 36 (SF-36) were defined as the medical burden and functional status, respectively. We analyzed the clinical factors associated with medical burden and functional status. RESULTS: We enrolled 142 patients (91 males and 51 females). The length and cost of hospitalization were 55.56 ± 27.09 (7-172) days and $14,070.17 ± 9289.39 (1611.87-48,722.35), respectively. A recurrence rate of 7.7% (11/142) and significant improvement of SF-36 at six months after completion of antibiotic treatment were noted (p < 0.05). Procedure-related (OR 2.702), C-reactive protein (CRP; OR 1.062), bacteremia (OR 4.966), additional surgical treatment (OR 6.524), recurrence (OR 12.453), and paraspinal abscess (OR 5.965) for above-average length of hospitalization were observed; female (OR 4.438), CRP (OR 1.071), bacteremia (OR 4.647), additional surgical treatment (OR 6.737), recurrence (OR 22.543), and extent of lesion (OR 1.431) for above-average cost of hospitalization; leg weakness (OR 15.966), white blood cell (WBC; OR 1.116), Charlson's comorbidity index (CCI, OR 1.485), and identification of causative bacteria (OR 2.913) for below-average initial SF-36 were observed; leg weakness (OR 7.975) and WBC (OR 1.094) for below-average 6-month SF-36 were the statistically significant clinical factors in the multivariable logistic regression analysis (p < 0.05). CONCLUSION: Recurrence and leg weakness were identified as the most important clinical factors for medical burden and functional status in PSI, respectively. We think that it is necessary to actively suppress recurrence and manage neurological deficits for decreasing medical burden and achieving favorable functional outcome in the treatment of PSI.

Assessment of Therapeutic Responses Using a Deep Neural Network Based on 18F-FDG PET and Blood Inflammatory Markers in Pyogenic Vertebral Osteomyelitis.

Background and Objectives: This study investigated the usefulness of deep neural network (DNN) models based on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and blood inflammatory markers to assess the therapeutic response in pyogenic vertebral osteomyelitis (PVO). Materials and Methods: This was a retrospective study with prospectively collected data. Seventy-four patients diagnosed with PVO underwent clinical assessment for therapeutic responses based on clinical features during antibiotic therapy. The decisions of the clinical assessment were confirmed as 'Cured' or 'Non-cured'. FDG-PETs were conducted concomitantly regardless of the decision at each clinical assessment. We developed DNN models depending on the use of attributes, including C-reactive protein (CRP), erythrocyte sedimentation ratio (ESR), and maximum standardized FDG uptake values of PVO lesions (SUVmax), and we compared their performances to predict PVO remission. Results: The 126 decisions (80 'Cured' and 46 'Non-cured' patients) were randomly assigned with training and test sets (7:3). We trained DNN models using a training set and evaluated their performances for a test set. DNN model 1 had an accuracy of 76.3% and an area under the receiver operating characteristic curve (AUC) of 0.768 [95% confidence interval, 0.625-0.910] using CRP and ESR, and these values were 79% and 0.804 [0.674-0.933] for DNN model 2 using ESR and SUVmax, 86.8% and 0.851 [0.726-0.976] for DNN model 3 using CRP and SUVmax, and 89.5% and 0.902 [0.804-0.999] for DNN model 4 using ESR, CRP, and SUVmax, respectively. Conclusions: The DNN models using SUVmax showed better performances when predicting the remission of PVO compared to CRP and ESR. The best performance was obtained in the DNN model using all attributes, including CRP, ESR, and SUVmax, which may be helpful for predicting the accurate remission of PVO.

Effects of D-Serine and MK-801 on Neuropathic Pain and Functional Recovery in a Rat Model of Spinal Cord Injury.

OBJECTIVE: Neuropathic pain is a common secondary complication of spinal cord injury (SCI). N-methyl-D-aspartate (NMDA) receptor activation is critical for hypersensitivity in neuropathic pain. This activation requires the binding of both glutamate and the D-serine co-agonist to the NMDA glycine site. We evaluated the effects of D-serine on neuropathic pain after SCI and explored the underlying molecular mechanisms. METHODS: Anesthetized rats underwent T9 spinal cord contusion (130 kdyn). D-serine (500 and 1,000 mg/kg) and MK-801 hydrogen maleate (2.0 mg/kg) were injected daily for 2 weeks, starting the day after SCI. Functional outcomes were assessed according to the Basso, Beattie, and Bresnahan scale, while histological outcomes were evaluated based on lesion volume and spared tissue area. Mechanical allodynia and thermal hyperalgesia were evaluated by measuring the withdrawal threshold of a von Frey filament and hot/cold plate latency. Western blotting was performed to determine the expression levels of Trpv1, Nav1.9, calcitonin gene-related peptide (CGRP), and ß-actin in damaged tissue. RESULTS: The withdrawal threshold values and latency of the D-serine group were significantly lower than those of the noninjection group. The MK-801 group showed higher threshold values and latencies than the other groups. Western blotting showed increased Nav1.9 and Trpv1 levels and lower CGRP levels in the D-serine group, whereas the MK-801 group showed the opposite results. CONCLUSION: D-serine increases neuropathic pain after traumatic SCI by mediating the NMDA receptor. NMDA receptor antagonists alleviate neuropathic pain after traumatic SCI.

Paraspinal muscle fatty degeneration as a predictor of progressive vertebral collapse in osteoporotic vertebral compression fractures.

BACKGROUND CONTEXT: Most osteoporotic vertebral compression fractures (OVCFs) are treated conservatively; however, in some patients, progressive vertebral body collapse leads to spinal deformity and cord compression. These complications are strongly associated with impaired performance activities of daily living and a poor quality of life. PURPOSE: To identify the role of the paraspinal muscle as a risk factor for progressive vertebral body collapse in patients with OVCF. STUDY DESIGN: This was a retrospective observational study. PATIENT SAMPLE: Fifty-five consecutive patients with OVCF who were treated conservatively from January 2018 to June 2020 in a single spine center and had a minimum follow-up of 6 months. OUTCOME MEASURES: A lateral plain radiograph in a neutral posture was taken when the patient was first diagnosed and at 1, 3, and 6 months after the first diagnosis. Vertebral height was measured at the point of maximal collapse of the affected vertebral body; vertebral collapse (%) was also measured. The cross-sectional area (CSA) and fatty degeneration of the paraspinal muscle were measured using the open-source software Image J. The visual analogue scale (VAS) scores were collected at the time of initial fracture diagnosis and at 1, 3, and 6 months. METHODS: The clinical and radiological data were analyzed. In the L4-5 intervertebral disc level, axial T2-weighted magnetic resonance imaging was used to measure the CSA and fatty degeneration of the paraspinal muscles. Correlation and multiple regression analyses were performed to analyze the risk factors associated with progressive vertebral body collapse. RESULTS: The vertebral collapse difference was strongly associated with paraspinal muscle fatty degeneration (r=0.684, p=.000) and body mass index (r=0.300, p=.026). Multiple linear regression analysis demonstrated that the risk factor for progression of vertebral collapse was paraspinal muscle fatty degeneration (ß=0.724, p=.000). There was a statistically significant correlation between the progression in vertebral collapse and VAS score at 3 (r=0.402, p=.002) and 6 months (r=0.604, p=.000). CONCLUSIONS: In patients with OVCF, fatty degeneration of the paraspinal muscle was a predictive factor for progressive vertebral body collapse. This study suggests that more attention should be paid to patients with paraspinal sarcopenia among those with OVCFs.

Risk factors for adjacent segment disease requiring reoperation after posterior lumbar interbody fusion with screw fixation: focus on paraspinal muscle, facet joint, and disc degeneration.

PURPOSE: Adjacent segment disease (ASD) requiring revision surgery is the most serious complication that can occur in patients undergoing posterior lumbar interbody fusion (PLIF) surgery. This study aimed to determine the risk factors for surgical ASD requiring revision surgery after PLIF with screw fixation surgery. We especially focused on paraspinal muscle, facet joint, and disc degeneration. METHODS: Among the patients who underwent PLIF with screw fixation due to degenerative spinal disease from January 2010 to December 2019, patients who underwent revision surgery for the development of ASD were enrolled. To evaluate the risk factors for surgical ASD, we selected a control group. Each patient in the control group was matched by age, sex, fusion level, number of fused segments, secondary MRI follow-up interval, and follow-up duration with a patient in the surgical ASD group. The radiographic and demographic data were compared between the surgical ASD and control groups. RESULTS: There were statistically significant differences between the two groups in radiological parameters of preoperative facet degeneration, facet effusion, facet angle, and fatty degeneration of the multifidus muscle. Multivariable logistic regression analysis revealed that preoperative facet effusion (odds ratio [OR] 6.48), preoperative facet angle (OR 1.24), and progression of fatty degeneration in the multifidus muscle (OR 1.07) were significant risk factors for surgical ASD. CONCLUSIONS: Preexisting high-grade adjacent facet effusion, sagittally oriented facet joint angle, and progressive fatty degeneration of the multifidus muscle are associated with the development of surgical ASD after PLIF surgery.

An unusual penetrating injury of the back: retroperitoneal hematoma from a glass stabbing injury: a case report.

In stab injury of the back visceral or vascular injuries are more uncommon than anterior abdominal stab injuries. The authors report the case of a 52-year-old man who presented to the emergency center with glass fragments lodged in his back after falling on a glass door on his back. On a retroperitoneal computed tomography (CT) scan, two foreign bodies were detected in left paraspinal and psoas muscles. Furthermore, hematoma with active bleeding was seen in the retroperitoneal cavity. He was referred to a general surgeon for retroperitoneal active bleeding, but emergency laparotomy was not deemed necessary considering the patient's stable condition in terms of vital signs, the level of hemoglobin, and the amount of bleeding. Therefore, we performed conservative treatment, such as packed cell transfusion and back compression, after removing the glass fragment through the posterior approach. The paravertebral muscle was dissected through the open wound, the tip of the piece of glass was accessible. The piece of glass was carefully removed, and there was no active bleeding. The postoperative CT scan showed continued active bleeding and increased retroperitoneal hematoma, but the patient's vital signs were stable. Conservative treatment was administered continuously, a follow-up CT scan taken a month later showed hematoma resolution and no more dye leakage. If the patient's vital signs are stable and the patient is neurologically intact, conservative treatment may be prioritized without laparotomy.

Ligamentum flavum hematoma following a traffic accident: A case report.

BACKGROUND: Ligamentum flavum hematoma (LFH) can cause compression of the spinal cord or nerve root, which results in neurological symptoms. We report a case of lumbar radicular pain due to LFH following a traffic accident. CASE SUMMARY: A 59-year-old man complained of left buttock and lateral thigh pain that was dull in nature after a traffic accident 18 d prior to presentation. Magnetic resonance imaging (MRI), taken 17 d after the traffic accident, revealed a mass lesion at the L4-5 Level. These MRI findings suggested subacute LFH. The patient's pain was not alleviated with conservative treatment, including oral medication and epidural steroid injection. After a partial-hemilaminectomy and removal of LFH, the patient's pain completely disappeared. CONCLUSION: Because early operation for decompression is important for a good outcome, clinicians should be able to determine LFH from MRI results and be aware of the possibility of LFH, especially in patients with a history of trauma.

Validity of Clinical Assessment Using Clinical Symptoms and C-Reactive Protein for Therapeutic Response in Pyogenic Vertebral Osteomyelitis: Analysis Based on 18F-FDG-PET.

Backgroundand objectives: The clinical assessment of therapeutic response in pyogenic vertebral osteomyelitis (PVO) has been usually performed based on the changes of clinical symptoms and blood inflammatory markers. Recently, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) has emerged as an alternative independent method. We analyzed the validity of the clinical assessment for detecting residual PVO based on 18F-FDG-PET. Materials and Methods: This study was conducted with 53 patients confirmed as lumbar PVO under retrospective design. All patients underwent clinical assessment using clinical symptoms and C-reactive protein (CRP) for therapeutic response after parenteral antibiotic therapy, which led to the decision of placement in the uncontrolled (group UC) or controlled (group C) group. The validity of clinical assessment was analyzed based on the cut-off values of FDG uptake for detecting residual PVO as references, which are already established in the previous literature. Results: The mean duration of parenteral antibiotic therapy and recurrence rate were 42.19 ± 15.84 (21-89) days and 9.4% (5/53), respectively. 18F-FDG-PETs were performed at 80 rounds of clinical assessment on 37.40 ± 13.15 (21-83) days of parenteral antibiotic therapy and divided: 31 into group UC and 49 into group C, according to the decisions of clinical assessment. Based on the cut-off values of FDG uptake, clinical assessment showed 48.4-58.1% of false positive for residual PVO in group UC. However, 18F-FDG-PET showed 8.2% (4/49) of false negative for residual PVO in group C, which led to recurrences. Conclusions: Clinical assessment using clinical symptoms and CRP for evaluating therapeutic response in PVO is still a useful method in terms of similar recurrence rate compared to 18F-FDG-PET. However, the high rate of false positive for residual PVO can prolong the use of unnecessary antibiotics and overall treatment period.

Comparison of Radiological and Functional Changes After Multi-Level Laminoplasty Between Cervical Spondylotic Myelopathy and Ossification of the Posterior Longitudinal Ligament.

AIM: To compare the radiological and functional changes after multi-level laminoplasty between patients with cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). MATERIAL AND METHODS: This study included 75 patients consisted with 32 of CSM (group A) and 43 of OPLL (group B) presenting a preserved cervical sagittal balance who underwent multi-level laminoplasty for cervical myelopathy. The radiological outcomes were analyzed with the following radiological parameters: C2?C7 Cobb angle in neutral (C2-7AN), flexed (C2-7AF), and extended (C2-7AE) neck postures; C2?C7 range of motion (C2-7ROM); T1 slope (T1S); and C2?C7 sagittal vertical axis (C2-7SVA). The functional outcomes were analyzed with the modified Japanese Orthopedic Association (mJOA) score, Nurick grade, and recovery rate. The radiological and functional outcomes between the two groups were evaluated at 12-month postoperatively. RESULTS: There were statistically significance increase of C2-7SVA in group A; and decrease of C2-7AF and C2-7ROM in group A and C2-7ROM in group B postoperatively (p < 0.05). However, C2-7AN showed no statistically significant inter-group differences and postoperative intra-group changes in both groups (p > 0.05). There were no statistically significant differences in the postoperative functional outcomes including mJOA score (p=0.251), Nurick grade (p=0.316), and recovery rate (p=0.435) between the two groups. CONCLUSION: Although there were no statistically significant differences in functional outcomes between the two groups, the group A showed a greater deterioration in sagittal balance with an increase of C2-7SVA than the group B after multi-level laminoplasty.

Delayed diagnosis of myelitis in a patient with Vogt-Koyanagi-Harada disease: a case report.

A case of myelitis following Vogt-Koyanagi-Harada (VKH) disease is reported, in which diagnosis and treatment were delayed. A 43-year-old male patient diagnosed with VKH disease presented at the Spine Centre of Yeungnam University Hospital, Daegu, Republic of Korea, with motor weakness, sensory deficit in both lower extremities, and dysuria for the previous 3 months. VKH disease had been diagnosed 15 months previously, based on vision loss in both eyes and the presence of bilateral nontraumatic granulomatous iridocyclitis, exudates, and retinal oedema. The patient exhibited severe motor weakness (right lower extremity, Medical Research Council (MRC) muscle scale, grade 2-0; left lower extremity, MRC grade 0). On cervical magnetic resonance imaging, a high-intensity T2 signal was observed in the spinal cord C4-C7 segments. Cerebrospinal fluid analysis revealed slightly elevated white blood cell counts. The patient was diagnosed with myelitis complicating VKH disease. Intravenous and oral corticosteroid therapy was administered. After steroid treatment, the patient's motor function in the right lower extremity was significantly improved (MRC grade 4-3). However, the left lower extremity did not show any improvement (MRC grade 0). To achieve a good treatment outcome, the diagnosis and treatment of myelitis in VKH disease should not be delayed.

Radiographic predictors of clinical outcome in traumatic brain injury after decompressive craniectomy.

BACKGROUND: Primary decompressive craniectomy (DC) is considered for traumatic brain injury (TBI) patients with clinical deterioration, presenting large amounts of high-density lesions on computed tomography (CT). Postoperative CT findings may be suitable for prognostic evaluation. This study evaluated the radiographic predictors of clinical outcome and survival using pre- and postoperative CT scans of such patients. METHODS: We enrolled 150 patients with moderate to severe TBI who underwent primary DC. They were divided into two groups based on the 6-month postoperative Glasgow Outcome Scale Extended scores (1-4, unfavorable; 5-8, favorable). Radiographic parameters, including hemorrhage type, location, presence of skull fracture, midline shifting, hemispheric diameter, effacement of cisterns, parenchymal hypodensity, and craniectomy size, were reviewed. Stepwise logistic regression analysis was used to identify the prognostic factors of clinical outcome and 6-month mortality. RESULTS: Multivariable logistic regression analysis revealed that age (odds ratio [OR] = 1.09; 95% confidence interval [CI] 1.032-1.151; p = 0.002), postoperative low density (OR = 12.58; 95% CI 1.247-126.829; p = 0.032), and postoperative effacement of the ambient cistern (OR = 14.52; 95% CI 2.234-94.351; p = 0.005) and the crural cistern (OR = 4.90; 95% CI 1.359-17.678; p = 0.015) were associated with unfavorable outcomes. Postoperative effacement of the crural cistern was the strongest predictor of 6-month mortality (OR = 8.93; 95% CI 2.747-29.054; p = 0.000). CONCLUSIONS: Hemispheric hypodensity and effacement of the crural and ambient cisterns on postoperative CT after primary DC seems to associate with poor outcome in patients with TBI.

Antimicrobial therapy and assessing therapeutic response in culture-negative pyogenic vertebral osteomyelitis: a retrospective comparative study with culture-positive pyogenic vertebral osteomyelitis.

BACKGROUND: There are still controversies regarding the treatment and outcomes in culture-negative pyogenic vertebral osteomyelitis (PVO). The purpose of this study is to investigate the antimicrobial therapy, assessment of therapeutic response, and outcome of culture-negative PVO compared to culture-positive PVO. METHODS: A retrospective study was performed with non-surgical lumbar PVO patients. The patients were divided into two groups based on the causative bacterial identification (CN group with culture-negative PVO and CP group with culture-positive PVO). The clinical features, use of antibiotics, laboratory data, and outcomes were compared between the two groups. RESULTS: Seventy-three patients with 41 (56.2%) of the CN group and 32 (43.8%) of the CP group were enrolled. The CN group showed a shorter duration of parenteral antibiotics (45.88 ± 16.14 vs. 57.31 ± 24.39, p = 0.019) but a tendency of prolonged duration of total (parenteral + oral) antibiotics (101.17 ± 52.84 vs. 84.19 ± 50.29 days, p = 0.168). When parenteral antibiotics were discontinued or switched to oral antibiotics, the mean erythrocyte segmentation rate (ESR, normal range: < 25 mm/h), C-reactive protein (CRP, normal range: < 0.5 mg/dL) level, and visual analog scale (VAS) score of back pain were 42.86 ± 24.05 mm/h, 0.91 ± 1.18 mg/dL, and 4.05 ± 1.07, respectively, with no significant differences between the two groups. The recurrence rates of CN and CP groups were 7.3% (3/41) and 6.3% (2/32), respectively (p = 1.000). The presence of epidural abscess was the most significant factor for the identification of causative bacteria (p = 0.002), and there was no significant relationship between the use of empirical antibiotics before tissue culture and the causative bacterial identification (p = 0.194). CONCLUSIONS: The CN group required a shorter duration of parenteral antibiotics than the CP group. Discontinuation of parenteral antibiotics or changing the administration route can be considered based on the values of ESR, CRP, and VAS score of back pain. The presence of epidural abscess was the most significant factor for the identification of causative bacteria.

Fracture-dislocation of L5 Combined with Multi-level Traumatic Spondylolisthesis of the Lower Lumbar Spine Treated via the Posterior-only Approach: A Case Report.

Fracture-dislocation of the lower lumbar spine, which is commonly caused by high-impact trauma and can lead to instability in the spine, is relatively rare. Surgical treatment is indicated to restore spinal balance, weight-bearing ability, and decompression of the neural elements. There are various available surgical options, including the posterior-only or anterior-only approaches, or a combination of them. However, there is still no definite classification and treatment strategy for fracture-dislocation of the lower lumbar spine. In this report, we describe a 65-year-old man presenting cauda equina syndrome caused by a fracture-dislocation of L5 combined with multi-level traumatic spondylolisthesis of the lower lumbar spine. The patient was treated via the posterior-only approach with neural decompression and anterior reconstruction with posterior instrumentation. We discuss the reasons why the posterior-only approach was decided upon and several meaningful points during the surgery in detail.

Therapeutic Effect of Teriparatide for Osteoporotic Thoracolumbar Burst Fracture in Elderly Female Patients.

OBJECTIVE: Teriparatide is known as an effective anabolic agent not only for severe osteoporosis but also for bone healing and union. We explored the possibility of teriparatide as an alternative treatment option for osteoporotic thoracolumbar (TL) burst fracture. METHODS: This retrospective study enrolled 35 female patients with mean age of 73.77±6.71 years (61-88) diagnosed as osteoporotic TL burst fracture with ≥4 of thoracolumbar injury classification and severity (TLICS) score and no neurological deficits. All patients were treated by teriparatide only (12 of group A), teriparatide plus vertebroplasty (12 of group B), or surgical fixation with fusion (11 of group C), and followed up for 12 months. Radiological outcomes were evaluated using radiological parameters including kyphotic angle (KA), segmental vertebral kyphotic angle (SVKA), compression ratio (CR), and vertebral body height (anterior [AH], middle [MH], posterior [PH]). Functional outcomes were evaluated using visual analog scale (VAS) and Macnab classification (MC). RESULTS: There were no statistical significant differences in age, bone mineral density (-3.36±0.73), and TLICS score (4.34±0.48) among the three groups (p>0.05). Teriparatide was administered during 8.63±2.32 months in group A and B. In 12-month radiological outcomes, there were significant restoration in SVKA, CR, AH, and MH of group B and KA, SVKA, CR, AH, and MH of group C compared to group A with no radiological changes (p<0.05). All groups showed similar significant improvements in 12-month functional outcomes, although group B and C showed a better 1-month VAS, 1-month MC, 3-month MC compared to group A (p<0.05). CONCLUSION: Non-surgical treatment with teriparatide showed similar 12-month functional outcomes compared to surgical fixation with fusion. The additional vertebroplasty to teriparatide and surgical fixation with fusion were more helpful to improve short-term functional outcomes with structural restoration compared to teriparatide only.

Clinical and Radiological Analysis of Pyogenic Vertebral Osteomyelitis Immediately after Successful Antimicrobial Therapy: Considerations for Assessing Therapeutic Response.

PURPOSE: The clinical and radiological abnormal findings continue even after successful treatment in pyogenic vertebral osteomyelitis (PVO). We analyzed the clinical and radiological features of cured PVO based on 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (FDG-PET/MRI) and compared the radiological differences between FDG-PET and MRI for assessing therapeutic response in PVO. METHODS: This study included 43 patients (28 men and 15 women) with lumbar PVO who had no recurrence after successful antimicrobial therapy. They were divided into two groups based on the location of maximum standardized FDG uptake value (SUVmax) of PVO lesion on FDG-PET/MRI when parenteral antibiotics were discontinued (31 in group A: Intervertebral structure; 12 in group B: Vertebral body and paravertebral muscle). The differences of clinical symptoms, hematological inflammatory indices, and radiological features were retrospectively analyzed. RESULTS: The patients were treated with 42.28 ± 14.58 (21-89) days of parenteral antibiotics. There were significant differences in C-reactive protein (0.97 ± 1.10 vs. 0.51 ± 0.31 mg/dL, p = 0.041; normal range of CRP < 0.5), back pain (4.29 ± 1.13 vs. 3.50 ± 1.00, p = 0.040; visual analog scale), and SUVmax (4.34 ± 1.24 vs. 5.89 ± 1.57, p < 0.001) between the two groups. In the distribution pattern of PVO lesions, FDG-PET overall showed recovery pattern earlier than MRI did (p < 0.001). CONCLUSIONS: In cured PVO, the clinical features vary depending on the location of major structural damage of PVO lesion. The involvement of intervertebral structure is related with sustained back pain and elevation of CRP, and vertebral body/paravertebral muscle shows favorable clinical features despite advanced structural damages.

Intramuscular hemangioma with hemorrhagic transformation arising from paraspinal muscles of posterior neck: A case report.

RATIONALE: Hemangiomas are usually found in cutaneous or mucosal layers, less than 1% of hemangiomas develop in skeletal muscles. Intramuscular hemangioma (IH) in the head and neck areas is relatively infrequent, accounting for 15% of IH. Most of them are identified as a benign mass, and rapid changes in size or internal bleeding are rare. PATIENT CONCERNS: A 60-year-old female patient presented with a 2-week history of sudden onset posterior neck pain. There was no neurological deficit except limited neck motion due to pain. The palpable mass was noted on the paraspinal muscles of cervicothoracic junction, which was located midline to left side portion with tenderness. DIAGNOSES: Magnetic resonance imaging demonstrated a round shaped, multi-lobulated, and well-defined mass lesion (4.1 × 2.6 × 0.9 cm) embedded from the inter-spinous space of T1-2 to the left paraspinal muscles. The lesion was iso-intense on T2-weighted images (WI), iso- to slightly low-intense on T1-WI, heterogeneous enhancement of intra- and peri-mass lesion on contrast-enhanced T1-WI. Vascular structures presented as signal voids were identified internally and around the mass lesion. Histological examination revealed a mixed-type hemangioma. INTERVENTIONS: The mass was removed completely including some of the surrounding muscles where boundaries were unclear between the mass and surrounding muscles with ligation of peritumoral vessels. Dark-brown colored blood was drained from the ruptured tumor capsule during the dissection. There was no bony invasion. OUTCOMES: The preoperative symptoms improved immediately after the operation. There is no residual or recurrence lesion by the 15-months follow-up. LESSONS: IH with hemorrhagic transformation in the head and neck is extremely rare. In the case of intramuscular tumors accompanied by a sudden onset of severe acute pain, we recommend considering a differential diagnosis of IH with hemorrhagic transformation. Complete resection of the tumor mass including surrounding muscles is required to prevent recurrence.

Giant intradural plexiform schwannoma of the lumbosacral spine - a case report and literature review.

BACKGROUND: Plexiform schwannoma (PS), variant of schwannoma, often involves multiple fascicles as plexiform neurofibroma, and is usually located superficially on the dermis and subcutaneous layers. Spinal PS is extremely rare, and there is insufficient information on its natural course and treatment strategy. We describe the clinical features and treatment of giant intradural PS at the lumbosacral spine. CASE PRESENTATION: A 66-year-old man presented with leg pain, paresthesia, and weakness for 2 years. Magnetic resonance imaging demonstrated a large mass lesion involving a continuous multi-lobulated bead-like mass and a cystic portion from L1 to S3. The lesion was iso-intense on T2-weighted images (WI), iso- to slightly low-intense on T1-WI, and heterogeneous enhancement on contrast-enhanced T1-WI. The large mass lesion had three portions, including a cystic mass at L1, continuous multi-lobulated bead-like mass with a cystic portion from L2 to S1, and multi-lobulated mass from S2 to S3, which were identified with severe adhesions with cauda equina on operative assessment. Grossly total extirpation was achieved at the lumbar spine, and remained three round shaped small masses at the lumbar area and a multi-lobulated round masses from S2 to S3 involving nerves related with motor function of the lower extremities and anal sphincter, respectively. Histological examination revealed multinodular or plexiform growth pattern composed of spindle-shaped tumor cells, which were diffusely and strongly positive for S100 protein with KI67 < 1%. There were no recurrence of preoperative symptoms and changes of the remained masses over a 2-year follow-up period. CONCLUSION: Subtotal extirpation to minimize neural deficits and close observation can be considered an appropriate treatment strategy for a giant spinal PS considering its benign prognosis and histological features, with a high risk of neurological damage during surgery.