Applications of Diffusion-Weighted MRI to the Musculoskeletal System.

Diffusion-weighted imaging (DWI) is an established MRI technique that can investigate tissue microstructure at the scale of a few micrometers. Musculoskeletal tissues typically have a highly ordered structure to fulfill their functions and therefore represent an optimal application of DWI. Even more since disruption of tissue organization affects its biomechanical properties and may indicate irreversible damage. The application of DWI to the musculoskeletal system faces application-specific challenges on data acquisition including susceptibility effects, the low T2 relaxation time of most musculoskeletal tissues (2-70 msec) and the need for sub-millimetric resolution. Thus, musculoskeletal applications have been an area of development of new DWI methods. In this review, we provide an overview of the technical aspects of DWI acquisition including diffusion-weighting, MRI pulse sequences and different diffusion regimes to study tissue microstructure. For each tissue type (growth plate, articular cartilage, muscle, bone marrow, intervertebral discs, ligaments, tendons, menisci, and synovium), the rationale for the use of DWI and clinical studies in support of its use as a biomarker are presented. The review describes studies showing that DTI of the growth plate has predictive value for child growth and that DTI of articular cartilage has potential to predict the radiographic progression of joint damage in early stages of osteoarthritis. DTI has been used extensively in skeletal muscle where it has shown potential to detect microstructural and functional changes in a wide range of muscle pathologies. DWI of bone marrow showed to be a valuable tool for the diagnosis of benign and malignant acute vertebral fractures and bone metastases. DTI and diffusion kurtosis have been investigated as markers of early intervertebral disc degeneration and lower back pain. Finally, promising new applications of DTI to anterior cruciate ligament grafts and synovium are presented. The review ends with an overview of the use of DWI in clinical routine. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.

Functional and Surgical Outcomes of Corpectomy in Patients with Unstable Spinal Fractures.

BACKGROUND: Unstable fractures of the spine should be managed surgically. An anterior approach allows for precise decompression of the vertebral canal and reconstruction of the fractured vertebral body. The aim of the study was to evaluate the functional and surgical outcomes of anterior surgical approaches for vertebral body removal and prosthetic reconstruction. MATERIAL AND METHODS: The objectives of this paper were accomplished by reviewing the course of treatment and treatment outcomes of patients operated on at the Orthopaedic Oncology Department in Brzozw and the Department of Orthopaedics and Traumatology in District Hospital in Stalowa Wola in the years 2020-2021. In total, the treatment of 54 patients was analyzed. The study only included patients with traumatic and pathological fractures who underwent a single-level corpectomy. A total of 18 patients with fractures of the cervical spine, 15 of the thoracic spine and 21 of lumbar spine were treated. Before and after treatment, patients' neurological status was assessed according to the Frankel classification, performance was assessed with the Karnofsky score and pain intensity was analyzed with a VAS. The vertebral wedge angle (alpha), the ratio of the anterior height of the fractured vertebral body to the anterior height of the upper adjacent vertebral body (a/c), the ratio of the anterior height to the posterior height of the fractured vertebra (a/b) and the distance between the vertebral endplates adjacent to the fractured vertebra, measured between their anterior edges (A-B) were assessed. The most common general medical and surgical complications were also evaluated. RESULTS: After the surgery, significant pain relief measured using a VAS was noted (the median was 7 preoperatively and 4 postoperatively) and an improvement in performance according to the Karnofsky score was observed (the median was 50 preoperatively and 70 postoperatively). Out of the 14 patients with neurologic deficits 11 improved, while 5 regained the ability to walk. In four patients, the implant migrated into an adjacent vertebra and three patients suffered a fracture of the upper adjacent vertebra. The correction of the spine deteriorated in all 7 patients. There was no postoperative neurological deterioration of patients and no infectious complications. During the surgery, three patients suffered dura mater injury, which was identified intraoperatively and repaired. CONCLUSIONS: 1. Corpectomy followed by vertebral body replacement is an effective and safe method that enables the restoration of the shape of the vertebra, restoration of the physciological spinal curvature and direct neural decompression. 2. The treatment outcomes are good. Pain significantly decreases and performance improves in most patients. 3. Treatment complications are rare. The most often observed complication was migration of the implant into an adjacent vertebral endplate, fractures above the place of fixation and dura mater injury.

Benign vs malignant vertebral compression fractures with MRI: a comparison between automatic deep learning network and radiologist's assessment.

OBJECTIVE: To test the diagnostic performance of a deep-learning Two-Stream Compare and Contrast Network (TSCCN) model for differentiating benign and malignant vertebral compression fractures (VCFs) based on MRI. METHODS: We tested a deep-learning system in 123 benign and 86 malignant VCFs. The median sagittal T1-weighted images (T1WI), T2-weighted images with fat suppression (T2WI-FS), and a combination of both (thereafter, T1WI/T2WI-FS) were used to validate TSCCN. The receiver operator characteristic (ROC) curve was analyzed to evaluate the performance of TSCCN. The accuracy, sensitivity, and specificity of TSCCN in differentiating benign and malignant VCFs were calculated and compared with radiologists' assessments. Intraclass correlation coefficients (ICCs) were tested to find intra- and inter-observer agreement of radiologists in differentiating malignant from benign VCFs. RESULTS: The AUC of the ROC plots of TSCCN according to T1WI, T2WI-FS, and T1WI/T2WI-FS images were 99.2%, 91.7%, and 98.2%, respectively. The accuracy of T1W, T2WI-FS, and T1W/T2WI-FS based on TSCCN was 95.2%, 90.4%, and 96.2%, respectively, greater than that achieved by radiologists. Further, the specificity of T1W, T2WI-FS, and T1W/T2WI-FS based on TSCCN was higher at 98.4%, 94.3%, and 99.2% than that achieved by radiologists. The intra- and inter-observer agreements of radiologists were 0.79-0.85 and 0.79-0.80 for T1WI, 0.65-0.72 and 0.70-0.74 for T2WI-FS, and 0.83-0.88 and 0.83-0.84 for T1WI/T2WI-FS. CONCLUSION: The TSCCN model showed better diagnostic performance than radiologists for automatically identifying benign or malignant VCFs, and is a potentially helpful tool for future clinical application. CLINICAL RELEVANCE STATEMENT: TSCCN-assisted MRI has shown superior performance in distinguishing benign and malignant vertebral compression fractures compared to radiologists. This technology has the value to enhance diagnostic accuracy, sensitivity, and specificity. Further integration into clinical practice is required to optimize patient management. KEY POINTS: • The Two-Stream Compare and Contrast Network (TSCCN) model showed better diagnostic performance than radiologists for identifying benign vs malignant vertebral compression fractures. • The processing of TSCCN is fast and stable, better than the subjective evaluation by radiologists in diagnosing vertebral compression fractures. • The TSCCN model provides options for developing a fully automated, streamlined artificial intelligence diagnostic tool.

The role of bone metastases on the mechanical competence of human vertebrae.

Spine is the most common site for bone metastases. The evaluation of the mechanical competence and failure location in metastatic vertebrae is a biomechanical and clinical challenge. Little is known about the failure behaviour of vertebrae with metastatic lesions. The aim of this study was to use combined micro-Computed Tomography (microCT) and time-lapsed mechanical testing to reveal the failure location in metastatic vertebrae. Fifteen spine segments, each including a metastatic and a radiologically healthy vertebra, were tested in compression up to failure within a microCT. Volumetric strains were measured using Digital Volume Correlation. The images of undeformed and deformed specimens were overlapped to identify the failure location. Vertebrae with lytic metastases experienced the largest average compressive strains (median ± standard deviation: -8506 ± 4748microstrain), followed by the vertebrae with mixed metastases (-7035 ± 15605microstrain), the radiologically healthy vertebrae (-5743 ± 5697microstrain), and the vertebrae with blastic metastases (-3150 ± 4641microstrain). Strain peaks were localised within and nearby the lytic lesions or around the blastic tissue. Failure between the endplate and the metastasis was identified in vertebrae with lytic metastases, whereas failure localised around the metastasis in vertebrae with blastic lesions. This study showed for the first time the role of metastases on the vertebral internal deformations. While lytic lesions lead to failure of the metastatic vertebra, vertebrae with blastic metastases are more likely to induce failure in the adjacent vertebrae. Nevertheless, every metastatic lesion affects the vertebral deformation differently, making it essential to assess how the lesion affects the bone microstructure. These results suggest that the properties of the lesion (type, size, location within the vertebral body) should be considered when developing clinical tools to predict the risk of fracture in patients with metastatic lesions.

Bone Marrow Adiposity and Fragility Fractures in Postmenopausal Women: The ADIMOS Case-Control Study.

CONTEXT: Noninvasive assessment of proton density fat fraction (PDFF) by magnetic resonance imaging (MRI) may improve the prediction of fractures. OBJECTIVE: This work aimed to determine if an association exists between PDFF and fractures. METHODS: A case-control study was conducted at Lille University Hospital, Lille, France, with 2 groups of postmenopausal women: one with recent osteoporotic fractures, and the other with no fractures. Lumbar spine and proximal femur (femoral head, neck, and diaphysis) PDFF were determined using chemical shift-based water-fat separation MRI (WFI) and dual-energy x-ray absorptiometry scans of the lumbar spine and hip. Our primary objective was to determine the relationship between lumbar spine PDFF and osteoporotic fractures in postmenopausal women. Analysis of covariance was used to compare PDFF measurements between patient cases (overall and according to the type of fracture) and controls, after adjusting for age, Charlson comorbidity index (CCI) and BMD. RESULTS: In 199 participants, controls (n = 99) were significantly younger (P < .001) and had significantly higher BMD (P < 0.001 for all sites) than patient cases (n = 100). A total of 52 women with clinical vertebral fractures and 48 with nonvertebral fractures were included. When PDFFs in patient cases and controls were compared, after adjustment on age, CCI, and BMD, no statistically significant differences between the groups were found at the lumbar spine or proximal femur. When PDFFs in participants with clinical vertebral fractures (n = 52) and controls were compared, femoral neck PDFF and femoral diaphysis PDFF were detected to be lower in participants with clinical vertebral fractures than in controls (adjusted mean [SE] 79.3% [1.2] vs 83.0% [0.8]; P = 0.020, and 77.7% [1.4] vs 81.6% [0.9]; P = 0.029, respectively). CONCLUSION: No difference in lumbar spine PDFF was found between those with osteoporotic fractures and controls. However, imaging-based proximal femur PDFF may discriminate between postmenopausal women with and without clinical vertebral fractures, independently of age, CCI, and BMD.

Bone Marrow Adipose Tissue Is Increased in Postmenopausal Women With Postsurgical Hypoparathyroidism.

CONTEXT: Suppression of bone turnover, greater trabecular volume, and normal-high normal all-site bone mineral density (BMD) are hallmarks of postsurgical hypoparathyroidism (HypoPT). Impairment in the trabecular microarchitecture with possible higher risk of vertebral fractures (VF) in women with postmenopausal HypoPT has also been described. Currently, no data on bone marrow adipose tissue (BMAT) are available in HypoPT. OBJECTIVE: To assess BMAT by magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) in postmenopausal women with chronic postsurgical HypoPT. METHODS: This cross-sectional pilot study, conducted at an ambulatory referral center, included 29 postmenopausal women (mean age 66 ± 8.4 years) with postsurgical HypoPT and 31 healthy postmenopausal women (mean age 63 ± 8.5). Lumbar spine MRI was performed and BMAT was measured by applying PRESS sequences on the L3 body. Lumbar spine, femoral neck, and total hip BMD were measured by dual x-ray absorptiometry (DXA); site-matched spine trabecular bone score (TBS) was calculated by TBS iNsight (Medimaps, Switzerland); VF assessment was performed with lateral thoracic and lumbar spine DXA. RESULTS: Fat content (FC) and saturation level (SL%) were higher (P <.0001 and P <.001), while water content (W) was lower in HypoPT compared to controls (P <.0001). FC significantly correlated with years since menopause and body weight (P <.05) in HypoPT, while TBS negatively correlated with FC and SL% (P <.05) and positively with residual lipids (RL) and W (P <.05). CONCLUSION: We demonstrate for the first time that BMAT is increased in postmenopausal women with postsurgical hypoparathyroidism and negatively associated with trabecular microarchitecture.

Significance of paraspinal muscle quality in risk between single and multiple osteoporotic vertebral fractures.

PURPOSE: To compare paraspinal muscle quality between patients with single and multiple osteoporotic vertebral fractures (OVFs) and evaluate the role of the paraspinal muscles in OVFs. METHODS: A total of 262 consecutive patients with OVFs were retrospectively analyzed in two groups: those with single OVF (n = 173) and those with multiple OVFs (n = 89). The cross-sectional area (CSA) and fatty degeneration of the paraspinal muscles were calculated from axial T2-weighted magnetic resonance imaging at the level of the L4 upper endplate by manual tracing in ImageJ software. Pearson's correlation analysis was performed to analyze correlations of paraspinal muscle quality to multiple OVFs. RESULTS: FD in all the paraspinal muscles was significantly higher in the multiple OVF group than the single OVF group (all p < 0.005). The functional CSA (fCSA) of the paraspinal muscles was significantly lower in the multiple OVF group than the single OVF group (all Ps < 0.001), except for the erector spine (p = 0.304). The Pearson's correlation analysis showed significant positive inter-correlations for the fCSAs of all the paraspinal muscles and the occurrence of multiple OVFs. CONCLUSIONS: The pure muscle volumes of the multifidus, psoas major, and quadratus lumborum were lower in patients with multiple OVFs than in those with a single OVF. Furthermore, the inter-correlation among all the paraspinal muscles indicate that the muscle-bone crosstalk profoundly existed in vertebral fracture cascade. Therefore, special attention to paraspinal muscle quality is needed to prevent progression to multiple OVFs.

Reverse Cortical Sign in Lumbar Burst Fracture.

"Reverse cortical sign" is a rare entity described in lumbar burst fracture that corresponds to the fracture fragment of the posterior wall of vertebral body, which has rotated 180 degrees with the cortical surface facing anteriorly and the cancellous surface facing posteriorly in the canal. Identifying this sign is crucial in deciding the line of management as it is a contraindication for ligamentotaxis. The advent of computed tomography scans with axial and sagittal reconstruction has allowed us to better describe these rare entities. We present a lumbar burst fracture with a reverse cortical sign describing its appearance in axial computed tomography scans, sagittal reconstruction, and magnetic resonance imaging.

Imaging parameters and clinical significance of posterior ligament complex injury in thoracolumbar fracture.

This study aims to investigate whether the combination of radiographs and computed tomography (CT) images can be used as an alternative means of magnetic resonance imaging examination or a preliminary screening method before examination, so as to improve the accuracy of determining the degree of posterior ligament complex injury in thoracolumbar fracture patients. From May 2011 to May 2019, the patients with thoracolumbar fracture were collected. A total of 150 patients were enrolled. The reference standard was 1.5T magnetic resonance imaging examination and lipid suppression sequence was applied. All radiographs and CT imaging results were measured in the Picture Archiving and Communication System workstation. The upper endplate angle and lower endplate angle, the percentage of vertebral height drop, the difference of inter-spinous process distance on CT images and the translation distance were statistically significant between the 2 groups (P < .05). Receiver operating characteristic curve showed that the diagnostic performance was excellent (all area under the curve > 0.7). To sum, the results showed that endplate angle + inter-spinous process distance on CT images combination had relatively high-quality diagnostic value for posterior ligamentous complex injury in thoracolumbar fracture patients.

Thoracolumbar Injury: The Thoracolumbar Injury Classification and Severity Scoring System or Modified Thoracolumbar Injury Classification and Severity?

OBJECTIVE: To compare the Thoracolumbar Injury Classification and Severity (TLICS) scoring system with its modified (mTLICS) version based on their agreement with the surgeon's opinion regarding treatment for patients with thoracolumbar injuries. Moreover, the Posterior Ligamentous Complex health was compared between intraoperative examinations and magnetic resonance imaging (MRI) reports. METHODS: MRI was obtained from 114 patients suffering thoracolumbar spinal trauma; the TLICS and mTLICS scores were measured. Approaches 1 and 2 were designed in both scoring systems based on assuming a total score of 4 as surgery and conservative management indication, respectively. Kappa was used to estimate the agreements between each approach and the surgeon's opinion on treatment. The receiver operating curve calculated the appropriate cut-off scores for the above systems over which surgical management was preferred. A P < 0.05 was considered significant. RESULTS: All the approaches showed moderate agreements with the surgeon's opinion on therapeutic management (TLICS: κapproach1 = 0.557, κapproach2 =0.508; mTLICS: κapproach1 = 0.557, κapproach2 = 0.551; P < 0.001 for each κ). A score >3.5 best illustrated the indication for surgery in both systems. The radiology report agreed stronger with intraoperatively observed ligamentous health when suspicious cases on MRI were reported as injured (κTLICS = 0.830, κmTLICS = 0.704) rather than healthy (κTLICS = 0.620, κmTLICS = 0.620). CONCLUSIONS: The surgeon's treatment plan agreed moderately with suggestions of the TLICS and mTLICS systems; surgery was the preferred management for the patients with a score of 4. Moreover, radiologic suspicion of Posterior Ligamentous Complex injury seemed to indicate a damaged ligament rather than a healthy one.

Balloon kyphoplasty for cervical spine metastasis: a technical note.

We report a simple technique of cervical spine balloon kyphoplasty performed for painful osteolytic metastatic disease in two patients.

The association between paraspinal muscle degeneration and osteoporotic vertebral compression fracture severity in postmenopausal women.

BACKGROUND: According to reports in the literature, osteoporotic vertebral compression fracture (OVCF) is associated with paraspinal muscle degeneration; however, the association between the severity of OVCF and paraspinal muscle degeneration is not clear. OBJECTIVE: The purpose of this study was to investigate the association between paraspinal muscle degeneration and OVCF severity in postmenopausal women. METHODS: Three hundred and seventy-six MRI images from 47 patients were collected and analyzed. Sagittal and axial coronal T2-weighted images were used to measure the fractured vertebra sagittal cross-sectional area (FSCSA), the adjacent normal vertebral body sagittal cross-sectional area (NSCSA), paraspinal muscle cross-sectional area (CSA), and the fat cross-sectional area (FCSA). The ratio of fractured vertebra compressed sagittal cross-sectional area (RCSA) and fatty infiltration ratio (FIR) was subsequently calculated. The formulas for RCSA and FIR calculations are as follows: RCSA = (NSCSA-FSCSA)/NSCSA; FIR = FCSA/CSA. RCSA and FIR represent the severity of OVCF and paraspinal muscle degeneration, respectively. RESULTS: The correlation between paraspinal muscle degeneration and OVCF severity was analyzed using the Pearson correlation, and multiple regression analysis was performed to explore related risk factors. OVCF severity was closely associated with paraspinal muscle degeneration (L3/4 FIR r= 0.704, P< 0.05; L4/5 FIR r= 0.578, P< 0.05; L5/S1 FIR r= 0.581, P< 0.05). Multiple regression analysis demonstrated that the risk factor for OVCF severity was L3/4 FIR (ß= 0.421, P= 0.033). CONCLUSION: OVCF severity was associated with the FIR of paraspinal muscles, and L3/4 FIR was a predictive factor for OVCF severity in postmenopausal women.

Prospective Study to Identify the Clinical and Radiologic Factors Predictive of Pseudarthrosis Development in Patients with Osteoporotic Vertebral Fractures.

BACKGROUND: Although most osteoporotic vertebral fractures (OVFs) heal conservatively, the most crucial undesirable outcome of conservative treatment is the failure to unite. There is paucity of literature on prevalence and risk factors of pseudarthrosis. METHODS: A prospective study involving patients (aged ≥50 years) undergoing conservative treatment of osteoporotic thoracic/lumbar fractures without neurodeficits was performed. Patients were followed for a minimum of 6 months and classified into 3 groups based on fracture healing: group 1, healing without collapse; group 2, healing with collapse; and group 3, pseudarthrosis. An assessment of all clinicoradiologic parameters at the time of injury and at each follow-up was performed and compared among patients belonging to the groups. RESULTS: A total of 77 patients (90 fractures) were studied. Sixty-six (73.3%), 16 (17.8%), and 28 (8.9%) fractures were classified under groups 1, 2, and 3, respectively. Mean ages in groups 1, 2, and 3 were 67.9 ± 9.1, 70.4 ± 7.6 and 72.3 ± 7.9 years (P = 0.08). Sex distribution was 62:15 (female/male). Seventy-three fractures (81.1%) occurred at the thoracolumbar junction. Stiff spine, ambulatory status, comorbidities, bone mineral density, and injury level were not associated with pseudarthrosis/collapse (P > 0.05). Male sex was associated with pseudarthrosis (P = 0.03). Based on regression analysis, initial vertebral height loss (radiography; P = 0.028), segmental Cobb (radiography; P = 0.019), vertebral comminution (computed tomography; P = 0.032), posterior ligamentous complex injury (magnetic resonance imaging; P = 0.048), and marrow change pattern (T2-weighted magnetic resonance imaging, Kanchiku classification; P = 0.037) were correlated with poorer outcome. Patients with pseudarthrosis had higher visual analog scale score (P = 0.04; final follow-up). CONCLUSIONS: Of OVFs, 8.9% developed pseudarthrosis. Male sex, severity of postinjury vertebral deformation (vertebral loss, kyphosis, comminution, and marrow changes) and presence of posterior ligamentous complex injury are risk factors for pseudarthrosis.

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.

Influence of Metastatic Bone Lesion Type and Tumor Origin on Human Vertebral Bone Architecture, Matrix Quality, and Mechanical Properties.

Metastatic spine disease is incurable, causing increased vertebral fracture risk and severe patient morbidity. Here, we demonstrate that osteolytic, osteosclerotic, and mixed bone metastasis uniquely modify human vertebral bone architecture and quality, affecting vertebral strength and stiffness. Multivariable analysis showed bone metastasis type dominates vertebral strength and stiffness changes, with neither age nor gender having an independent effect. In osteolytic vertebrae, bone architecture rarefaction, lower tissue mineral content and connectivity, and accumulation of advanced glycation end-products (AGEs) affected low vertebral strength and stiffness. In osteosclerotic vertebrae, high trabecular number and thickness but low AGEs, suggesting a high degree of bone remodeling, yielded high vertebral strength. Our study found that bone metastasis from prostate and breast primary cancers differentially impacted the osteosclerotic bone microenvironment, yielding altered bone architecture and accumulation of AGEs. These findings indicate that therapeutic approaches should target the restoration of bone structural integrity. © 2022 American Society for Bone and Mineral Research (ASBMR).

SATB2-associated syndrome: characterization of skeletal features and of bone fragility in a prospective cohort of 19 patients.

BACKGROUND: Individuals with pathogenic variants in SATB2 display intellectual disability, speech and behavioral disorders, dental abnormalities and often features of Pierre Robin sequence. SATB2 encodes a transcription factor thought to play a role in bone remodeling. The primary aim of our study was to systematically review the skeletal manifestations of SATB2-associated syndrome. For this purpose, we performed a non-interventional, multicenter cohort study, from 2017 to 2018. We included 19 patients, 9 females and 10 males ranging in age from 2 to 19 years-old. The following data were collected prospectively for each patient: clinical data, bone markers and calcium and phosphate metabolism parameters, skeletal X-rays and bone mineral density. RESULTS: Digitiform impressions were present in 8/14 patients (57%). Vertebral compression fractures affected 6/17 patients (35%). Skeletal demineralization (16/17, 94%) and cortical thinning of vertebrae (15/17) were the most frequent radiological features at the spine. Long bones were generally demineralized (18/19). The distal phalanges were short, thick and abnormally shaped. C-telopeptide (CTX) and Alkaline phosphatase levels were in the upper normal values and osteocalcin and serum procollagen type 1 amino-terminal propeptide (P1NP) were both increased. Vitamin D insufficiency was frequent (66.7%). CONCLUSION: We conclude that SATB2 pathogenic variants are responsible for skeletal demineralization and osteoporosis. We found increased levels of bone formation markers, supporting the key role of SATB2 in osteoblast differentiation. These results support the need for bone evaluation in children and adult patients with SATB2-associated syndrome (SAS).

Surgical fixation of pathologic and traumatic spinal fractures using single position surgery technique in lateral decubitus position.

STUDY DESIGN: Retrospective Case Series. OBJECTIVES: This study aims to determine complications, readmission, and revision surgery rates in patients undergoing single position surgery (SPS) for surgical treatment of traumatic and pathologic thoracolumbar fractures. METHODS: A multi-center review of patients who underwent SPS in the lateral decubitus position (LSPS) for surgical management of traumatic or pathologic thoracolumbar fractures between January 2016 and May 2020 was conducted. Operative time, estimated blood loss (EBL), intraoperative complications, postoperative complications, readmissions, and revision surgeries were collected. RESULTS: A total of 12 patients with a mean age of 45 years (66.67% male) were included. The majority of patients underwent operative treatment for acute thoracolumbar trauma (66.67%) with a mean injury severity score (ISS) of 16.71. Mean operative time was 175.5 min, mean EBL of 816.67 cc. Five patients experienced a complication, two of which required revision surgery for additional decompression during the initial admission. All ambulatory patients were mobilized on postoperative day 1. The mean hospital length of stay (LOS) was 9.67 days. CONCLUSION: The results of this case series supports LSPS as a feasible alternative to the traditional combined anterior-posterior approach for surgical treatment of pathologic and thoracolumbar fractures. These results are similar to reductions in operative time, EBL, and LOS seen in the elective spine literature with LSPS. LEVEL OF EVIDENCE: IV.

Factors Associated With Skeletal Muscle Mass Increase by Rehabilitation in Older Adults With Vertebral Compression Fractures.

Age-related sarcopenia and osteoporosis-related fractures are critical health issues. Therefore, this study aimed to assess skeletal muscle mass changes in older patients with vertebral compression fractures undergoing rehabilitation and to evaluate factors associated with muscle increases. This study included 179 patients aged ≥80 years in rehabilitation wards with vertebral compression fractures. Appendicular skeletal muscle index was significantly higher at discharge (5.22 ± 1.04 kg/m2, p < .001) than on admission (5.03 ± 1.00 kg/m2). Multiple logistic regression analysis showed that length of hospital stay was significantly associated with increased skeletal muscle index (odds ratios, 1.020; 95% confidence intervals [1.000, 1.032]), whereas age, sex, body mass index, functional independence measure, protein intake, and exercise therapy duration were not. Participants with vertebral compression fractures aged ≥80 years achieved significantly increased skeletal muscle mass in rehabilitation wards. In addition, length of hospital stay was the factor independently associated with increased skeletal muscle index.

High viscosity bone cement vertebroplasty versus low viscosity bone cement vertebroplasty in the treatment of mid-high thoracic vertebral compression fractures.

BACKGROUND CONTEXT: As science and technology have advanced, novel bone cements with numerous formulated ingredients have greatly evolved and been commercialized for vertebroplasty. Recently, viscosity has been a focus to achieve better clinical outcomes and fewer complications. Meanwhile, the experience in the treatment of mid (T7-9) to high (T4-6) thoracic vertebral compression fractures is limited. PURPOSE: The objective of this study was to identify the different outcomes between high-viscosity bone cement (HVBC) and low-viscosity bone cement (LVBC) used to repair mid (T7-9)- and high (T4-6)- thoracic vertebral compression fractures. STUDY DESIGN/SETTING: This study was a single-center, retrospective cohort study PATIENT SAMPLE: A consecutive series of 107 patients with a total of 144 vertebrae was included. OUTCOME MEASURES: The anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), local kyphotic angle (KA), Cobb angle (CA), and other associated parameters were evaluated radiologically at several time points-preoperative, surgery day 0, postoperative day 1, and 6-month follow-up. Pain evaluation was assessed by using a visual analog scale (VAS) before and 6 months after the procedure. METHODS: The patients were divided into two groups according to the viscosity of the bone cement used, and plain film and magnetic resonance imaging (MRI) of the vertebrae were used to calculate parameters. The patient characteristics; bone cement brand; changes in AVH, MVH, PVH, KA, CA, and VAS; and complications of each patient were recorded and then analyzed. RESULTS: Both groups showed increased vertebral body height, corrected KA, and CA after vertebroplasty. There were no significant differences between the HVBC and LVBC groups (ΔAVH: 2.19±2.60 vs. 2.48±3.09, p=.555; ΔMVH: 1.25±3.15 vs. 1.89±2.58, p=.192; ΔKA: -5.46±4.58 vs -5.37±4.47, p=.908; and ΔCA: -4.22±4.23 vs. -4.56±5.17, p=.679). There were significant preoperative to postoperative and preoperative to follow-up changes in AVH (HVBC, p=.012 and .046, respectively; LVBC, p=.001 and .015, respectively); a significant preoperative to postoperative change in MVH (HVBC, p=.045; LVBC, p=.001); and significant preoperative to postoperative and preoperative to follow-up changes in KA and CA (KA: HVBC, p=0.000 and .003, respectively; LVBC, p=.000 and .000, respectively; CA: HVBC, p=.017 and .047, respectively; LVBC, p=.006 and .034, respectively). The volume of cement injected was significantly higher with HVBC (3.66±1.36 vs. 3.11±1.53, p=.024), and the use of HVBC was associated fewer cases with cement leakage (26 vs. 45, p=.002). Furthermore, there was no difference between the groups in the incidence of adjacent fracture. Both groups showed an improved VAS score at follow-up, with statistically greater improvement in the HVBC group (2.40±1.53 vs. 3.07±1.69, p=.014). Moreover, significantly fewer patients with a VAS score ≥ 3 were found in the HVBC group (22 vs. 39, p=.004) CONCLUSIONS: HVBC and LVBC are safe and effective to treat mid-to-high level thoracic vertebral compression fractures. Compared with LVBC, HVBC shows less cement leakage, a greater injection volume, and better postoperative pain relief.