Understanding Variations in the Management of Displaced Distal Radius Fractures With Satisfactory Reduction.

BACKGROUND: The American Academy of Orthopaedic Surgeons has set forth Clinical Practice Guidelines (CPGs) to help guide management of closed, displaced distal radius fractures (DRFs). There still exists variation in practice regarding operative vs nonoperative decision-making. This study aims to identify which factors influence the decision to treat DRFs not indicated for surgery by the CPGs after initial closed reduction. METHODS: Fifteen sets of DRFs and clinical vignettes were distributed via email to over 75 orthopedic residency programs, Orthopaedic Trauma Association, and New York Society for Surgery of the Hand membership. A Qualtrics survey collected respondent demographics, choice of treatment, and rationale. RESULTS: Responses were received from 106 surgeons and resident trainees. The odds of selecting operative management for fractures with 5 or more radiographic instability signs versus 3 or 4 was 3.11 (P < .05). Age over 65, higher patient activity level, and dominant-hand injury were associated with greater odds of operative management (3.4, 30.28, and 2.54, respectively). In addition, surgeons with more years in practice and high-volume surgeons had greater odds of selecting operative management (2.43 and 2.11, respectively). CONCLUSIONS: Assessment of instability at the time of injury, patient age and activity level, as well as surgeon volume and time in practice independently affect the decision to manage well-reduced DRF with surgical or nonsurgical treatment. The source of heterogeneity in the treatment of these fractures is borne at least in part from a lack of formal direction on the importance of prereduction instability from the CPGs.

A Survey Study of Surgeons and Anesthesiologists Regarding Perioperative Multimodal Analgesia for Opioid-Tolerant Patients.

PURPOSE: Perioperative pain management of opioid-tolerant patients can be challenging. Although regional anesthesia and multimodal analgesics may be beneficial, these modalities are often underused. It is unclear whether practice patterns for perioperative pain management are determined by the knowledge, attitudes, and beliefs of surgeons and anesthesiologists. DESIGN: Descriptive survey. METHODS: Using a Qualtrics survey, we polled a randomly selected group of 25 surgeons and 25 anesthesiologists regarding their knowledge, attitudes, beliefs, and practices for pain management in an opioid-tolerant patient. FINDINGS: Of 25, 23 anesthesiologists and 18/25 surgeons responded to the survey. Demographics were similar between the 2 groups. Most of the participant surgeons and anesthesiologists believed that pain management may be challenging in an opioid-tolerant patient. However, only 56% of surgeons would recommend a preoperative pain consultation. Most surgeons and anesthesiologists believed in the efficacy of regional anesthetics. However, 43% of surgeons would not advocate for a regional block, perhaps due to their perception of the added perioperative time. Multimodal analgesics were widely accepted by both surgeons and anesthesiologists. CONCLUSIONS: There is an urgent need to reinforce the importance of patient-centered care, with a specific focus on addressing knowledge gaps and improving perceptions for all the members of the team, including surgeons, anesthesiologists, and perioperative nursing teams, if optimal outcomes are to be achieved for our patients.

Cardiac Hemangioma: A Rare Tumor Presenting as Postpartum Chest Pain.

Pulmonary embolism, peripartum cardiomyopathy, acute myocardial infarction, aortic dissection, anxiety, and gastroesophageal reflux disease are known causes of chest pain during the peripartum period. A cardiac tumor is a rare cause of chest pain during this time period. While cardiac myxomas during pregnancy have been reported, cardiac hemangiomas are exceptionally rare. To the best of our knowledge, there are no existing case reports regarding cardiac hemangiomas in either pregnant or postpartum patients. Here, we present a 23-year-old female who presented with visual changes, headache, and midsternal pain and was subsequently found to have a cardiac hemangioma.

Non-destructive classification of unlabeled cells: Combining an automated benchtop magnetic resonance scanner and artificial intelligence.

In order to treat degenerative diseases, the importance of advanced therapy medicinal products has increased in recent years. The newly developed treatment strategies require a rethinking of the appropriate analytical methods. Current standards are missing the complete and sterile analysis of the product of interest to make the drug manufacturing effort worthwhile. They only consider partial areas of the sample or product while also irreversibly damaging the investigated specimen. Two-dimensional T1 / T2 MR relaxometry meets these requirements and is therefore a promising in-process control during the manufacturing and classification process of cell-based treatments. In this study a tabletop MR scanner was used to perform two-dimensional MR relaxometry. Throughput was increased by developing an automation platform based on a low-cost robotic arm, resulting in the acquisition of a large dataset of cell-based measurements. Two-dimensional inverse Laplace transformation was used for post-processing, followed by data classification performed with support vector machines (SVM) as well as optimized artificial neural networks (ANN). The trained networks were able to distinguish non-differentiated from differentiated MSCs with a prediction accuracy of 85%. To increase versatility, an ANN was trained on 354 independent, biological replicates distributed across ten different cell lines, resulting in a prediction accuracy of up to 98% depending on data composition. The present study provides a proof of principle for the application of T1 / T2 relaxometry as a non-destructive cell classification method. It does not require labeling of cells and can perform whole mount analysis of each sample. Since all measurements can be performed under sterile conditions, it can be used as an in-process control for cellular differentiation. This distinguishes it from other characterization techniques, as most are destructive or require some type of cell labeling. These advantages highlight the technique's potential for preclinical screening of patient-specific cell-based transplants and drugs.

The Use of Enhanced Recovery After Surgery Protocols and Sugammadex in a Friedreich Ataxia Patient Who Underwent Robotic Surgery: A Case Report of a Patient Who Required No Postoperative Opioids and Was Discharged Home Earlier Than Anticipated.

Robotic surgery has shown to have numerous benefits over traditional and laparoscopic surgery, namely, superior precision and improved recovery with shorter hospital stays. However, robotic surgery also presents several issues, including hemodynamic changes related to positioning and the use of pneumoperitoneum. These matters can be problematic in patients with neuromuscular conditions such as Friedreich ataxia (FRDA). Due to a baseline weakened musculature and a higher prevalence of cardiac disease and scoliosis, patients with FRDA may not be as likely to tolerate the cardiopulmonary physiologic changes associated with robotic surgery. Additionally, positioning for robotic surgery can be challenging in FRDA patients who have progressed to spasticity and contractures. To the best of our knowledge, there are no case reports of approaches specifically discussing anesthesia management for robotic surgery in the FRDA patient population. Anesthesia in general must be carefully planned in FRDA patients to allow for the best possible recovery and minimize complications. Due to the underlying neuromuscular compromise seen in these patients, their ability to recover from the pharmacologic and physiologic changes associated with anesthesia can be more difficult. They are prone to sensitivity to opioids, sedatives, and neuromuscular blocking agents (NMBAs) and are less likely to tolerate hemodynamic changes. Our review revealed no literature to suggest the routine use of Enhanced Recovery After Surgery (ERAS) protocols in FRDA patients or in patients with neuromuscular disease in general. The use of sugammadex has also been shown to be safe, and literature suggests superiority in both the general population and those with neuromuscular conditions. Our understanding is that there is very limited literature in regard to the safe use of sugammadex in FRDA patients.

Successful Neuromuscular Blockade Reversal Using Sugammadex and Neostigmine Failed to Prevent Myasthenic Crisis After Emergency Surgery: A Case Report.

Recent literature suggests that the use of sugammadex for the reversal of neuromuscular blocking agents (NMBAs) reduces the risk of postoperative myasthenic crisis (MC) in patients with myasthenia gravis (MG), particularly after thymectomy, but studies are lacking on emergency surgeries. We achieved successful intraoperative reversal of neuromuscular blockade (NMB) using a combination of sugammadex and neostigmine (with glycopyrrolate). However, MC was not avoided and reintubation was required on postoperative day 1. A 65-year-old male with a longstanding history of MG presented to the emergency department with complaints of abdominal pain, diarrhea, vomiting, chills, and fatigue for three days. A computed tomography (CT) scan of the abdomen showed acute appendicitis, for which he underwent a laparoscopic appendectomy on hospital day 1. The patient received successful general anesthesia with a rapid sequence induction using a smaller than average dose of rocuronium, given his history of MG. At the conclusion of the case, sugammadex followed by neostigmine/glycopyrrolate and a subsequent dose of sugammadex were given, with reversal of NMB. The patient was successfully extubated but required reintubation on postoperative day 1 for hypercapnic respiratory failure. Our case report on this patient with MG yields two topics that have not been extensively examined. First, dual therapy with sugammadex and neostigmine/glycopyrrolate may provide significant clinical benefit over individual therapy for NMBA reversal, given that their mechanisms of action are different and particularly when sugammadex is given prior to neostigmine/glycopyrrolate. Second, anesthesia literature is lacking on MG patients undergoing emergency surgeries. While sugammadex has been promising in medically optimized non-emergent surgeries, we discuss here a case where sugammadex failed to prevent MC in the emergency surgery setting and a look into what may provide patients with the best chance for avoiding postoperative MC.

COVID-19 Vaccine-Related Arthritis: A Descriptive Study of Case Reports on a Rare Complication.

Large-scale coronavirus disease 2019 (COVID-19) vaccination programs have been rolled out worldwide. Vaccines that are widely used globally include mRNA vaccines, adenoviral vector vaccines, and inactivated whole-virus vaccines. COVID-19 vaccines can lead to varying side effects. Among the most common of these adverse effects are pain at the injection site, fatigue, and headaches. Some side effects, however, are not very well documented, and these include joint-related adverse effects. In this review, we assess the epidemiology and clinical features of post-COVID-19 vaccination joint-related adverse effects based on the analysis of 16 patient case reports. Based on our analysis, we found that females formed the majority of the cases, accounting for 62.5% of patients, while 37.5% of the cases were males. The mean age of presentation among the patients was 54.8 years, with a standard deviation (SD) of 17.49 years. In 37.5% of the cases, patients received the Sinovac vaccine. The proportion of patients who received other vaccines was as follows: the Pfizer vaccine: 31.25%; Sputnik V: 12.5%; Moderna, AstraZeneca, and Covaxin: 6.25% each. The characteristics of joint-related adverse effects following COVID-19 vaccination were analyzed in this study. We identified several key findings related to factors such as age, gender, type of vaccine, clinical features, and diagnosis modality. Our analysis showed that more cases were reported among individuals who received the Sinovac vaccine, as compared to the others. Further research is required to examine the underlying cause of this association.

Optically Sensitive and Magnetically Identifiable Supraparticles as Indicators of Surface Abrasion.

Identifying and ensuring the integrity of products plays an important role in today's globalized world. Miniaturized information taggants in the packaging surface are therefore required to monitor the product itself instead of applying external labels. Ideally, multiple types of information are stored in such additives. In this work, micrometer-sized core-shell particles (supraparticles) were developed to provide material surfaces with both an identifier and a surface abrasion indication functionality. The core of the supraparticles contains iron oxide nanoparticles that allow identification of the surface with a spectral magnetic code resolved by magnetic particle spectroscopy. The fluorescent silica nanoparticles in the supraparticle shell can be abraded by mechanical stress and resolved by fluorescence spectroscopy. This provides information about the mechanical integrity of the system. The application as surfaces, that contain several types of information in one supraparticle, was demonstrated here by incorporating such bifunctional supraparticles as additives in a surface coating.

Cephalometry without complex dedicated postprocessing in an oriented magnetic resonance imaging dataset: a pilot study.

OBJECTIVES: Magnetic resonance imaging (MRI) enables a 3D-volume-imaging without ionizing radiation. Therefore, it was the aim of this study to present a post-processing-free method for cephalometric analysis of a MRI-dataset and to examine whether there is a significant difference between cephalometric analysis of conventional 2D cephalograms and MRI scans. METHODS: One MRI scan each was performed on three cadaver heads using a 3T-MR-scanner. Cephalometric analysis was conducted directly on the 3D dataset. All reference points were projected onto a virtual sagittal plane that was perpendicular to the Frankfort horizontal plane. Double-sided points were averaged. Cephalometric angles were measured from the projected points. Results were compared with cephalometric measurements on conventional lateral cephalometric radiographs (LCRs). The cephalometric analysis was performed by five raters. RESULTS: 390-angle measurements were obtained. The inter-rater reliability was high [intraclass correlation coefficients (ICCs) ≥ 0.74 for all angles]. Differences between the measurements on the cephalograms and MRI scans ranged between -0.91° (-1.88°, 0.07°) and 0.97° (-0.63°, 2.57°) on average and were equivalent with respect to a margin of [-2°, 2°] in all angles except L1-Me-Tgo (Bonferroni-Holm-corrected P < 0.05 in all angles except L1-Me-Tgo). The best match was found for the SNA angle. CONCLUSION: The clinical comparability of the MRI- and LCR-based cephalometry could be stated. Using MRI in orthodontics would reduce radiation exposure and the risk of stochastic radiation damage, which is of importance especially in younger patients.

Superparamagnetic Iron Oxide Particles (VSOPs) Show Genotoxic Effects but No Functional Impact on Human Adipose Tissue-Derived Stromal Cells (ASCs).

Adipose tissue-derived stromal cells (ASCs) represent a capable source for cell-based therapeutic approaches. For monitoring a cell-based application in vivo, magnetic resonance imaging (MRI) of cells labeled with iron oxide particles is a common method. It is the aim of the present study to analyze potential DNA damage, cytotoxicity and impairment of functional properties of human (h)ASCs after labeling with citrate-coated very small superparamagnetic iron oxide particles (VSOPs). Cytotoxic as well as genotoxic effects of the labeling procedure were measured in labeled and unlabeled hASCs using the MTT assay, comet assay and chromosomal aberration test. Trilineage differentiation was performed to evaluate an impairment of the differentiation potential due to the particles. Proliferation as well as migration capability were analyzed after the labeling procedure. Furthermore, the labeling of the hASCs was confirmed by Prussian blue staining, transmission electron microscopy (TEM) and high-resolution MRI. Below the concentration of 0.6 mM, which was used for the procedure, no evidence of genotoxic effects was found. At 0.6 mM, 1 mM as well as 1.5 mM, an increase in the number of chromosomal aberrations was determined. Cytotoxic effects were not observed at any concentration. Proliferation, migration capability and differentiation potential were also not affected by the procedure. Labeling with VSOPs is a useful labeling method for hASCs that does not affect their proliferation, migration and differentiation potential. Despite the absence of cytotoxicity, however, indications of genotoxic effects have been demonstrated.

Reversible magnetism switching of iron oxide nanoparticle dispersions by controlled agglomeration.

The controlled agglomeration of superparamagnetic iron oxide nanoparticles (SPIONs) was used to rapidly switch their magnetic properties. Small-angle X-ray scattering (SAXS) and dynamic light scattering showed that tailored iron oxide nanoparticles with phase-changing organic ligand shells agglomerate at temperatures between 5 °C and 20 °C. We observed the concurrent change in magnetic properties using magnetic particle spectroscopy (MPS) with a temporal resolution on the order of seconds and found reversible switching of magnetic properties of SPIONs by changing their agglomeration state. The non-linear correlation between magnetization amplitude from MPS and agglomeration degree from SAXS data indicated that the agglomerates' size distribution affected magnetic properties.

3D Imaging and metabolomic profiling reveal higher neuroactive kavalactone contents in lateral roots and crown root peels of Piper methysticum (kava).

BACKGROUND: Kava is an important neuroactive medicinal plant. While kava has a large global consumer footprint for its clinical and recreational use, factors related to its use lack standardization and the tissue-specific metabolite profile of its neuroactive constituents is not well understood. RESULTS: Here we characterized the metabolomic profile and spatio-temporal characteristics of tissues from the roots and stems using cross-platform metabolomics and a 3D imaging approach. Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry revealed the highest content of kavalactones in crown root peels and lateral roots. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) imaging revealed a unique tissue-specific presence of each target kavalactone. X-ray micro-computed tomography analysis demonstrated that lateral roots have morphological characteristics suitable for synthesis of the highest content of kavalactones. CONCLUSIONS: These results provide mechanistic insights into the social and clinical practice of the use of only peeled roots by linking specific tissue characteristics to concentrations of neuroactive compounds.

Developing opioid prescribing recommendations in the postoperative orthopedic setting.

BACKGROUND: The use of opioid analgesics in the United States has increased nearly fourfold since 1999 resulting in a similar increase in opioid-related overdose deaths. Although the Centers for Disease Control published guidelines for prescribing chronic opioids, there is a lack of guidance for prescribing postoperative opioids. OBJECTIVE: To offer an evidence-based approach to prescribing opioids for post-operative pain management in the orthopedic setting. METHODS: A narrative review was performed of studies evaluating and quantifying opioid use in orthopedic patients in the postoperative setting, as well as studies analyzing patient satisfaction and perception with regards to opioid use. RESULTS: Studies show that postoperative pain may not be the largest contributing factor to developing an opioid use disorder, but rather patient factors such as tobacco and substance use disorder, mental health disorders, anxiety, mood disorders, pre-existing chronic pain, and recent opioid use may play a role. The review also found that most patients do not utilize significant portions of prescribed opioids and most do not require a refill. This trend leaves patients with thousands of unused pills, which are either retained, shared, or diverted. Although there is no guideline for prescribing opioids postoperatively, data suggest that clinicians can prescribe smaller dosages and fewer quantities of opioids initially. There are also non-opioid strategies that can be employed to reduce opioid consumption. CONCLUSION: There is a need for more high quality research to be conducted to standardize postoperative opioid prescribing patterns and create best practice guidelines to guide clinicians. Orthopedic practices should consider creating institutional guidelines to reduce the amount of opioids prescribed.

A substitute variety for agronomically and medicinally important Serenoa repens (saw palmetto).

Serenoa repens (saw palmetto) berries are one of the most consumed medicinal herbs in the United States and the wild green variety is used in the initial therapy of benign prostatic hyperplasia (BPH), globally. Use of saw palmetto is approved by the German Commission E, and several clinical trials are underway for evaluation of its efficacy. Exploitation of its habitats and over foraging imperil this plant, which only grows in the wild. This is the first study, to propose the use of the S. repens forma glauca (silver variety) as a qualitative substitute for the wild variety, to support its conservation. We compared tissue microstructures and lipid and water distribution through spatial imaging and examined metabolite distribution of three tissue domains and whole berries. This combined approach of 3D imaging and metabolomics provides a new strategy for studying phenotypic traits and metabolite synthesis of closely related plant varieties.

Calcium fluoride based multifunctional nanoparticles for multimodal imaging.

New multifunctional nanoparticles (NPs) that can be used as contrast agents (CA) in different imaging techniques, such as photoluminescence (PL) microscopy and magnetic resonance imaging (MRI), open new possibilities for medical imaging, e.g., in the fields of diagnostics or tissue characterization in regenerative medicine. The focus of this study is on the synthesis and characterization of CaF2:(Tb3+,Gd3+) NPs. Fabricated in a wet-chemical procedure, the spherical NPs with a diameter of 5-10 nm show a crystalline structure. Simultaneous doping of the NPs with different lanthanide ions, leading to paramagnetism and fluorescence, makes them suitable for MR and PL imaging. Owing to the Gd3+ ions on the surface, the NPs reduce the MR T1 relaxation time constant as a function of their concentration. Thus, the NPs can be used as a MRI CA with a mean relaxivity of about r = 0.471 mL·mg-1·s-1. Repeated MRI examinations of four different batches prove the reproducibility of the NP synthesis and determine the long-term stability of the CAs. No cytotoxicity of NP concentrations between 0.5 and 1 mg·mL-1 was observed after exposure to human dermal fibroblasts over 24 h. Overall this study shows, that the CaF2:(Tb3+,Gd3+) NPs are suitable for medical imaging.

Determination of the mesio-distal tooth width via 3D imaging techniques with and without ionizing radiation: CBCT, MSCT, and µCT versus MRI.

Objective: The purpose of this study was to estimate the feasibility and accuracy of mesio-distal width measurements with magnetic resonance imaging (MRI) in comparison to conventional 3D imaging techniques [multi-slice CT (MSCT), cone-beam CT (CBCT), and µCT]. The measured values of the tooth widths were compared to each other to estimate the amount of radiation necessary to enable orthodontic diagnostics. Material and Methods: Two pig skulls were measured with MSCT, CBCT, µCT, and MRI. Three different judges were asked to determine the mesio-distal tooth width of 14 teeth in 2D tomographic images and in 3D segmented images via a virtual ruler in every imaging dataset. Results: Approximately 19% (27/140) of all test points in 2D tomographic slice images and 12% (17/140) of the test points in 3D segmented images showed a significant difference (P ≤ 0.05). The largest significant difference was 1.6mm (P < 0.001). There were fewer significant differences in the measurement of the tooth germs than in erupted teeth. Conclusions: Measurement of tooth width by MRI seems to be clinically equivalent to the conventional techniques (CBCT and MSCT). Tooth germs are better illustrated than erupted teeth on MRI. Three-dimensional segmented images offer only a slight advantage over 2D tomographic slice images. MRI, which avoids radiation, is particularly appealing in adolescents if these data can be corroborated in further studies.

High isotropic resolution magnetic resonance imaging of the mandibular canal at 1.5 T: a comparison of gradient and spin echo sequences.

OBJECTIVES: The precision of localizing the mandibular canal prior to surgical intervention depends on the achievable resolution, whereas identification of the nerve depends on the image contrast. In our study, we developed new protocols based on gradient and spin echo sequences. The results from both sequences were quantitatively compared for their agreement to identify the most suitable approach. METHODS: By limiting the field of view to one side of the mandible, three-dimensional acquisitions with T1 weighted gradient and spin echo sequences were performed with 0.5 × 0.5 × 0.5 mm3 resolution within 6.5 min covering the mandibular canal from the mandibular to the mental foramen. Aliasing artefacts were suppressed by different techniques. A manual segmentation of the mandibular canal from seven healthy volunteers was performed on this section by three different observers. The surface distance of the segmented volumes was computed between both sequences as well as between the different observers as a measure of equality. RESULTS: The quantitative comparison of the segmentation resulted in an average surface distance of 0.26 ± 0.05 mm between both sequences and an interobserver difference of 0.26 ± 0.08 mm for gradient and 0.29 ± 0.07 mm for spin echo data. By repeated evaluation, a difference of 0.15 ± 0.02 mm for gradient and 0.18 ± 0.03 mm for spin echo data was observed, indicating a slightly higher variability for spin echo images. CONCLUSIONS: Both sequences can be used to achieve high-resolution images with good contrast and can be used for precise localization of the mandibular canal. Despite a slightly increased difference for the spin echo data, the advantage of an easy and robust setup remains.

A Web-Based Operating Room Management Educational Tool.

In 2010, our department instituted a nonclinical, administrative rotation in operating room management for anesthesiology residents. Subsequently, we mandated the rotation for all senior anesthesiology residents in 2013. In 2014, under the auspices of the American Society of Anesthesiologists, we developed a web-based module covering the basics of finance, accounting, and operating room management. A multiple-choice test was given to residents at the beginning and end of the rotation, and we compared the mean scores between residents who took the traditional course and residents who took the web-based module. We found no significant difference between the groups of residents, suggesting that the web-based module is as effective as traditional didactics.

Adipose Mesenchymal Stromal Cell-Based Therapy for Severe Osteoarthritis of the Knee: A Phase I Dose-Escalation Trial.

UNLABELLED: : Osteoarthritis (OA) is the most widespread musculoskeletal disorder in adults. It leads to cartilage damage associated with subchondral bone changes and synovial inflammation, causing pain and disability. The present study aimed at evaluating the safety of a dose-escalation protocol of intra-articular injected adipose-derived stromal cells (ASCs) in patients with knee OA, as well as clinical efficacy as secondary endpoint. A bicentric, uncontrolled, open phase I clinical trial was conducted in France and Germany with regulatory agency approval for ASC expansion procedure in both countries. From April 2012 to December 2013, 18 consecutive patients with symptomatic and severe knee OA were treated with a single intra-articular injection of autologous ASCs. The study design consisted of three consecutive cohorts (six patients each) with dose escalation: low dose (2 × 10(6) cells), medium dose (10 × 10(6)), and high dose (50 × 10(6)). The primary outcome parameter was safety evaluated by recording adverse events throughout the trial, and secondary parameters were pain and function subscales of the Western Ontario and McMaster Universities Arthritis Index. After 6 months of follow-up, the procedure was found to be safe, and no serious adverse events were reported. Four patients experienced transient knee joint pain and swelling after local injection. Interestingly, patients treated with low-dose ASCs experienced significant improvements in pain levels and function compared with baseline. Our data suggest that the intra-articular injection of ASCs is a safe therapeutic alternative to treat severe knee OA patients. A placebo-controlled double-blind phase IIb study is being initiated to assess clinical and structural efficacy. SIGNIFICANCE: Although this phase I study included a limited number of patients without a placebo arm, it showed that local injection of autologous adipose-derived stem cells was safe and well tolerated in patients with knee osteoarthritis. This study also provides encouraging preliminary evidence of efficacy. Larger and controlled long-term studies are now mandatory to confirm whether this new strategy of cell therapy can improve pain and induce structural benefit in osteoarthritis.

MRI vs. CT for orthodontic applications: comparison of two MRI protocols and three CT (multislice, cone-beam, industrial) technologies.

OBJECTIVES: To examine the relative usefulness and suitability of magnetic resonance imaging (MRI) in daily clinical practice as compared to various technologies of computed tomography (CT) in addressing questions of orthodontic interest. METHODS: Three blinded raters evaluated 2D slices and 3D reconstructions created from scans of two pig heads. Five imaging modalities were used, including three CT technologies-multislice (MSCT), cone-beam CT (CBCT), and industrial (µCT)-and two MRI protocols with different scan durations. Defined orthodontic parameters were rated one by one on the 2D slices and the 3D reconstructions, followed by final overall ratings for each modality. A mixed linear model was used for statistical analysis. RESULTS: Based on the 2D slices, the parameter of visualizing tooth-germ topography did not yield any significantly different ratings for MRI versus any of the CT scans. While some ratings for the other parameters did involve significant differences, how these should be interpreted depends greatly on the relevance of each parameter. Based on the 3D reconstructions, the only significant difference between technologies was noted for the parameter of visualizing root-surface morphology. Based on the final overall ratings, the imaging performance of the standard MRI protocol was noninferior to the performance of the three CT technologies. CONCLUSIONS: On comparing the imaging performance of MRI and CT scans, it becomes clear that MRI has a huge potential for applications in daily clinical practice. Given its additional benefits of a good contrast ratio and complete absence of ionizing radiation, further studies are needed to explore this clinical potential in greater detail.