Small volar fragment in the lunate fossa leads to volar tilt loss after volar plate fixation for AO/OTA type-C distal radius fracture.

OBJECTIVES: The relationship between volar fragment size and postoperative volar tilt loss in complete articular distal radius fracture is not well known. In this study, we measured precise radiological parameters to help identify other factors that might contribute to volar tilt loss. MATERIAL AND METHODS: We retrospectively reviewed the radiological examinations and charts of 256 patients with distal radial fracture who underwent volar locking plate fixation between March 2014 and July 2022. Radiological parameters were measured based on preoperative CT and immediate postoperative radiographs. Univariate and multivariate linear regression analysis was performed to identify relevant factors associated with volar tilt loss following volar locking plate fixation. The receiver operating characteristic curve was used to identify the cutoff value of the independent parameters. RESULTS: On univariate analysis, 2 radiologic parameters on preoperative CT (volar fragment length at the lunate fossa, and teardrop angle) and 4 on immediate postoperative X-ray (radial inclination, radial length, capitate shift, and volar tilt) were significantly associated with postoperative volar tilt loss. On multivariate linear regression analysis, the risk of volar tilt loss increased as the capitate moved toward the back of the radial shaft. The cut-off for anteroposterior length in the lunate fossa was 6.5 mm. CONCLUSIONS: AO/OTA type-C distal radius fractures with <6.5 mm anteroposterior length in the lunate fossa had significantly higher rates of malunion with dorsal deformity. In addition, preoperative teardrop angle <37.2 ° and immediate postoperative volar tilt <3.7º are also predictors of postoperative volar tilt loss.

Identification of L5 vertebra on lumbar spine radiographs using deep learning.

OBJECTIVE: Deep learning is an advanced machine-learning approach that is used in several medical fields. Here, we developed a deep learning model using an object detection algorithm to identify the L5 vertebra on anteroposterior lumbar spine radiographs, and assessed its detection accuracy. METHODS: We retrospectively recruited 150 participants for whom both anteroposterior whole-spine and lumbar spine radiographs were available. The anteroposterior lumbar spine radiographs of these patients were used as the input data. Of the 150 images, 105 (70%) were randomly selected as the training set, and the remaining 45 (30%) were assigned to the validation set. YOLOv5x, of the YOLOv5 family model, was used to detect the L5 vertebra area. RESULTS: The mean average precisions 0.5 and 0.75 of the trained L5 detection model were 99.2% and 96.9%, respectively. The model's precision was 95.7% and its recall was 97.8%. Furthermore, 93.3% of the validation data were correctly detected. CONCLUSION: Our deep learning model showed an outstanding ability to identify L5 vertebrae.

The applicability of noncontact sensors in the field of rehabilitation medicine.

A noncontact sensor field is an innovative device that can detect, measure, or monitor physical properties or conditions without direct physical contact with the subject or object under examination. These sensors use a variety of methods, including electromagnetic, optical, and acoustic technique, to collect information about the target without physical interaction. Noncontact sensors find wide-ranging applications in various fields such as manufacturing, robotics, automobiles, security, environmental monitoring, space industry, agriculture, and entertainment. In particular, they are used in the medical field, where they provide continuous monitoring of patient conditions and offer opportunities in rehabilitation medicine. This article introduces the potential of noncontact sensors in the field of rehabilitation medicine.

Extracellular Vesicles from Human Adipose Tissue-Derived Mesenchymal Stem Cells Suppress RANKL-Induced Osteoclast Differentiation via miR122-5p.

Researchers are increasingly interested in cell therapy using mesenchymal stem cells (MSCs) as an alternative remedy for osteoporosis, with fewer side effects. Thus, we isolated and characterized extracellular vesicles (EVs) from human adipose tissue-derived MSCs (hMSCs) and investigated their inhibitory effects on RANKL-induced osteoclast differentiation. Purified EVs were collected from the supernatant of hMSCs by tangential flow filtration. Characterization of EVs included typical evaluation of the size and concentration of EVs by nanoparticle tracking analysis and morphology analysis using transmission electron microscopy. hMSC-EVs inhibited RANKL-induced differentiation of bone marrow-derived macrophages (BMDMs) into osteoclasts in a dose-dependent manner. F-actin ring formation and bone resorption were also reduced by EV treatment of osteoclasts. In addition, EVs decreased RANKL-induced phosphorylation of p38 and JNK and expression of osteoclastogenesis-related genes in BMDMs treated with RANKL. To elucidate which part of the hMSC-EVs plays a role in the inhibition of osteoclast differentiation, we analyzed miRNA profiles in hMSC-EVs. The results showed that has-miR122-5p was present at significantly high read counts. Overexpression of miR122-5p in BMDMs significantly inhibited RANKL-induced osteoclast differentiation and induced defects in F-actin ring formation and bone resorption. Our results also revealed that RANKL-induced phosphorylation of p38 and JNK and osteoclast-specific gene expression was decreased by miR122-5p transfection, which was consistent with the results of hMSC-EVs. These findings suggest that hMSC-EVs containing miR122-5p inhibit RANKL-induced osteoclast differentiation via the downregulation of molecular mechanisms and could be a preventive candidate for destructive bone diseases.

Predictors of Vertebral Endplate Fractures after Oblique Lumbar Interbody Fusion.

Background: Cage subsidence after oblique lumbar interbody fusion (OLIF) induces restenosis and adversely affects patient outcomes. Many studies have investigated the causes of subsidence, one of which is endplate fracture (EF). This study aimed to identify predictors of EF after OLIF. Methods: This retrospective study reviewed consecutive patients who underwent OLIF at a single institute between August 2019 and February 2022. A total of 104 patients were enrolled. The patients' demographic data and surgical details were collected through chart reviews. Radiographic variables were measured. Related variables were also analyzed using binomial logistic regression, dividing each group into those with versus without EF. Results: EF occurred at 30 of 164 levels (18.3%), and the binary logistic analysis revealed that sex (odds ratio [OR], 11.07), inferior endplate concave depth (OR, 1.95), disc wedge angle (OR, 1.22), lumbar lordosis (OR, 1.09), pelvic incidence (OR, 1.07), sagittal vertical axis (OR, 1.02), sacral slope (OR, 0.9), L3-4 level (OR, 0.005), and L4-5 level (OR, 0.004) were significantly related to EF. Conclusions: OLIF in older Asian patients should be performed carefully after recognizing the high possibility of EF and confirming the factors that should be considered preoperatively.

Multidisciplinary approach to sarcopenia: a narrative review.

Sarcopenia is a condition in which muscle mass and strength are decreased and muscle function is impaired. It is an indicator of frailty and loss of independence in older adults. It is also associated with increased physical disability, which increases the risk of falls. As a multifactorial disease, sarcopenia is caused by a combination of factors including aging, hormonal changes, nutritional deficiencies, and physical inactivity. Understanding the underlying pathophysiology of sarcopenia and identifying its different causes is critical to developing effective prevention and treatment strategies. This review summarizes the pathophysiology, consequences, diagnostic methods, and multidisciplinary approaches to sarcopenia.

Progressive unilateral leg weakness after lumbar decompression due to ischemic monomelic neuropathy misdiagnosed as epidural hematoma: A CARE-compliant case report.

RATIONALE: Ischemic monomelic neuropathy (IMN) is a disease that occurs after acute arterial occlusion or steal phenomenon in an extremity that results in single or multiple axonal mononeuropathies in the distal limb without the classical features of limb ischemia, including a skin color change, limb swelling, and ischemic claudication. IMN can easily be misdiagnosed as any other neuropathic disorder. Here we present a case of IMN that was misdiagnosed as spinal epidural hematoma. PATIENT CONCERNS: A 77-year-old man presented with sudden motor weakness and pain in his left foot and calf 5 days after a bilateral L4 to 5 posterior decompression for lumbar spinal stenosis. His symptoms progressed over the next 5 days. The strengths of the left ankle dorsiflexors, first toe extensors, and ankle plantar flexors were Medical Research Council 0. On brain and whole-spine magnetic resonance imaging, no specific abnormalities correlated with his symptoms were observed. Computed tomography angiography of the lower extremities revealed segmental occlusion of the left common femoral artery and multifocal severe stenoses in the bilateral anterior and posterior tibial arteries of the left leg. No skin color change or swelling was observed in the left lower extremity. DIAGNOSIS: Based on his clinical features and imaging findings, he was diagnosed with IMN. INTERVENTION: The patient underwent thrombectomy of the left femoral artery. OUTCOMES: After the treatment, his pain almost completely disappeared. LESSONS: When patients exhibit acute-onset pain in the unilateral limb with or without motor weakness but no correlated abnormality on spinal magnetic resonance imaging or computed tomography, clinicians should consider the possibility of IMN.

Therapeutic potential of small extracellular vesicles derived from mesenchymal stem cells for spinal cord and nerve injury.

Neural diseases such as compressive, congenital, and traumatic injuries have diverse consequences, from benign mild sequelae to severe life-threatening conditions with associated losses of motor, sensory, and autonomic functions. Several approaches have been adopted to control neuroinflammatory cascades. Traditionally, mesenchymal stem cells (MSCs) have been regarded as therapeutic agents, as they possess growth factors and cytokines with potential anti-inflammatory and regenerative effects. However, several animal model studies have reported conflicting outcomes, and therefore, the role of MSCs as a regenerative source for the treatment of neural pathologies remains debatable. In addition, issues such as heterogeneity and ethical issues limited their use as therapeutic agents. To overcome the obstacles associated with the use of traditional agents, we explored the therapeutic potentials of extracellular vesicles (EVs), which contain nucleic acids, functional proteins, and bioactive lipids, and play crucial roles in immune response regulation, inflammation reduction, and cell-to-cell communication. EVs may surpass MSCs in size issue, immunogenicity, and response to the host environment. However, a comprehensive review is required on the therapeutic potential of EVs for the treatment of neural pathologies. In this review, we discuss the action mechanism of EVs, their potential for treating neural pathologies, and future perspectives regarding their clinical applications.

High reliability and accuracy of dynamic magnetic resonance imaging in the diagnosis of cervical Spondylotic myelopathy: a multicenter study.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a critical condition that results in significant neurologic deterioration. An accurate diagnosis is essential for determining its outcome and prognosis. The pathology is strongly associated with dynamic factors; therefore, dynamic magnetic resonance (MR) image could be crucial to accurately detect CSM. However, very few studies have evaluated the reliability and accuracy of dynamic MR in CSM. In this study, we aimed to compare intra- and interobserver reliabilities and accuracy of dynamic MR in detecting CSM using sagittal MR scans of the neck in the flexed, neutral, and extended position. METHODS: Out of 131 patients who underwent surgical treatments for CSM, 107 were enrolled in this study. The patient underwent three-types of sagittal MR scans that were obtained separately in different neck positions (neutral, flexion, and extension postures). The MR scans of the cervical spine were evaluated independently by three spine professionals, on the basis of tabled questionnaires. For accuracy, we performed a receiver operator characteristic analysis, and the overall discriminating ability of each method was measured by calculating the area under the ROC curve. The Cohen's kappa coefficient and the Fleiss-generalized kappa coefficient was used to the inter- and intra-observer reliabilities. RESULTS: The intraobserver reliability (using the Cohen's kappa coefficient) and interobserver reliability (using the Fless kappa coefficient) were respectively 0.64 and 0.52 for the neutral sagittal MR. The accuracy of neutral sagittal MR in detecting CSM was 0.735 (95% CI, 0.720 to 0.741) while that of extension sagittal MRI was 0.932 (96% CI, 0.921 to 0.948). CONCLUSIONS: Dynamic MR significantly showed better diagnostic reliability and accuracy in detecting CSM compared to conventional MR. In particular, extension MR scans could provide a more accurate diagnosis than other images.

Diagnostic Technology for Spine Pathology.

Diagnostic techniques for spinal pathologies have been developed in accordance with advances in technology. Accurate diagnosis of spinal pathology is essential for appropriate management of spinal diseases. Since the development of X-rays in 1895 and computed tomography (CT) in 1967, several diagnostic imaging modalities have been utilized for detecting spinal pathologies, including radiography, CT, magnetic resonance imaging, and radionuclide imaging. In addition to diagnostic imaging technologies, electrodiagnostic tests, including electromyography and nerve conduction studies, play a significant role as diagnostic tools, as spinal diseases are mostly profoundly associated with pathologies of the neural structures, such as the spinal cord and nerve root, and extent of injury at the structure cannot be adequately detected by conventional imaging techniques. In patient-specific treatment strategies, usage of diagnostic modalities is of great importance; thus, we should be aware of the basic details and approaches of the different diagnostic modalities. In this review, the authors discuss the details of the technologies that aid in the diagnosis of spinal pathologies.

Mesenchymal Stem Cell-Derived Exosomes and Their Therapeutic Potential for Osteoarthritis.

Exosomes are nano-sized vesicles (50-150 nm in diameter) that contain nucleic acids (e.g., microRNA and messenger RNA), functional proteins, and bioactive lipids. They are secreted by various types of cells, including B cells, T cells, reticulocytes, dendritic cells, mast cells, epithelial cells, and mesenchymal stem cells (MSCs). They perform a wide variety of functions, including the repair of damaged tissues, regulation of immune responses, and reduction in inflammation. When considering the limitations of MSCs, including issues in standardization and immunogenicity, MSC-derived exosomes have advantages such as small dimensions, low immunogenicity, and lack of requirement for additional procedures for culture expansion or delivery. MSC-derived exosomes have shown outstanding therapeutic effects through chondro-protective and anti-inflammatory properties. MSC-derived exosomes may enable a new therapeutic paradigm for the treatment of osteoarthritis. However, further research is needed to prove their clinical effectiveness and feasibility.

Bone Marrow Aspirate Concentrate: Its Uses in Osteoarthritis.

Human bone marrow (BM) is a kind of source of mesenchymal stem cells (MSCs) as well as growth factors and cytokines that may aid anti-inflammation and regeneration for various tissues, including cartilage and bone. However, since MSCs in BM usually occupy only a small fraction (0.001%) of nucleated cells, bone marrow aspirate concentrate (BMAC) for cartilage pathologies, such as cartilage degeneration, defect, and osteoarthritis, have gained considerable recognition in the last few years due to its potential benefits including disease modifying and regenerative capacity. Although further research with well-designed, randomized, controlled clinical trials is needed to elucidate the exact mechanism of BMAC, this may have the most noteworthy effect in patients with osteoarthritis. The purpose of this article is to review the general characteristics of BMAC, including its constituent, action mechanisms, and related issues. Moreover, this article aims to summarize the clinical outcomes of BMAC reported to date.

Causes and treatment outcomes of revision surgery after open reduction and internal fixation of tibial plateau fractures.

PURPOSE: Treatment of a tibial plateau fracture (TPF) remains controversial and is generally challenging. Many authors report good results after conventional open reduction and internal fixation in TPF, but complications still occur. This study analyzed causes and outcomes of revision surgery for TPF. The usefulness of a flow chart for revision surgery in TPF was also evaluated. METHODS: We reviewed all patients who underwent more than two operations for a TPF between 2008 and 2015. Finally, 24 cases were selected and retrospectively investigated. The medial tibial plateau angle and proximal posterior tibial angle were radiologically evaluated. The American Knee Society Score (AKSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), range of motion (ROM), and bone union time were investigated after surgery. RESULTS: Revision surgery for infection was performed in eight cases, for nonunion in six cases, for posttraumatic arthritis (with total knee arthroplasty) in six cases, and for other reasons in four cases. The mean clinical AKSS at final follow-up was 87.3 ± 5.3 (range, 75-95), the functional AKSS was 81.9 ± 5.5 (range, 70-90), the WOMAC score was 9.9 ± 3.1 (range, 5-16), the flexion ROM was 119.8 ± 16.5° (range, 100-150°), and the extension ROM was 2.5 ± 3.3° (range, 0-10°). CONCLUSIONS: Although complications cannot be avoided in some cases, good clinical outcomes are possible when patients are divided according to the presence or absence of infection, with selection of appropriate revision surgery as shown in the flow chart. If an infection is present, treatment should be based on the presence or absence of bone union. If there is no infection, treatment should be based on the presence or absence of nonunion, post-traumatic arthritis, malunion, or immediate post-operative malreduction.