Return to Sport in Professional Athletes After Cartilage Restoration Surgery of the Knee: A Systematic Review and Meta-Analysis Demonstrates Gender Inequality and the Need for Improved Reporting.

Objective: To synthesize the literature concerning return to sport (RTS) and related outcomes after cartilage restoration surgery of the knee in professional athletes.

Design: Cochrane, PubMed, and OVID/Medline databases were queried for data pertaining to RTS after knee cartilage surgery in professional athletes. Demographic information, cartilage lesion characteristics, and RTS-specific information were extracted.

SMART-PET: a Self-SiMilARiTy-aware generative adversarial framework for reconstructing low-count [18F]-FDG-PET brain imaging.

Introduction: In Positron Emission Tomography (PET) imaging, the use of tracers increases radioactive exposure for longitudinal evaluations and in radiosensitive populations such as pediatrics. However, reducing injected PET activity potentially leads to an unfavorable compromise between radiation exposure and image quality, causing lower signal-to-noise ratios and degraded images. Deep learning-based denoising approaches can be employed to recover low count PET image signals: nonetheless, most of these methods rely on structural or anatomic guidance from magnetic resonance imaging (MRI) and fails to effectively preserve global spatial features in denoised PET images, without impacting signal-to-noise ratios.

Automated, Transferable, and Ethanol-Free Radiosynthesis of [C]Butanol.

Cerebral blood flow and blood-brain barrier permeability assessment are crucial hemodynamic parameters to measure under neurological conditions. In conjunction with positron emission tomography (PET), oxygen-15-labeled water has emerged as a gold standard for measuring cerebral perfusion; however, at higher flow rates, [O]water extraction becomes nonlinear. In such a scenario, freely diffusible [C]butanol can provide a truer estimate.

Design, Synthesis, and Preclinical Evaluation of a High-Affinity F-Labeled Radioligand for Myocardial Growth Hormone Secretagogue Receptor Before and After Myocardial Infarction.

The peptide hormone ghrelin is produced in cardiomyocytes and acts through the myocardial growth hormone secretagogue receptor (GHSR) to promote cardiomyocyte survival. Administration of ghrelin may have therapeutic effects on post-myocardial infarction (MI) outcomes. Therefore, there is a need to develop molecular imaging probes that can track the dynamics of GHSR in health and disease to better predict the effectiveness of ghrelin-based therapeutics.

Team Approach: Neuromuscular Training for Primary and Secondary Prevention of Anterior Cruciate Ligament Injury.

Neuromuscular training is a method of performance optimization-typically combining plyometrics, balancing training, agility, and dynamic stabilization-predicated on improving the efficiency of fundamental movement patterns. Neuromuscular training has consistently been shown to reduce the risk of anterior cruciate ligament injury, particularly for athletes engaged in activities associated with noncontact knee injuries (i.e.

Frugal and Translatable [O]O Production for Human Inhalation with Direct Delivery from the Cyclotron to a Hybrid PET/MR.

Oxygen-15 (β+, t = 122 s) radiolabeled diatomic oxygen, in conjunction with positron emission tomography, is the gold standard to quantitatively measure the metabolic rate of oxygen consumption in the living human brain. We present herein a protocol for safe and effective delivery of [O]O over 200 m to a human subject for inhalation. A frugal quality control testing procedure was devised and validated.

Orthopaedic Surgery Residency: Perspective of Applicants and Program Directors on Medical Student Virtual Experiences.

Introduction: Orthopaedic Residency Directors advised against visiting subinternship rotations in the peak of the pandemic. To adapt, programs offered multiple virtual experiences. The purpose of this study was to evaluate programs and applicants perceptions regarding the value of virtual experiences during the 2020 to 2021 application cycle and their utility in future application cycles.

Effect of Postoperative Immobilization Time on PROMIS Scores and Clinical outcomes in Ankle Fracture Patients.

Background: Ankle fractures are among the most common injuries treated by orthopaedic surgeons, yet little guidance exists in postoperative protocols for ankle fractures concerning time of immobilization. Here, we aim to investigate the association between early mobilization and patient-reported outcomes. Our null hypothesis was that no difference in Patient-Reported Outcomes Measurement Information System (PROMIS) scores would be identified in patients when comparing the effect of time of immobilization.

Development of a minimally invasive simultaneous estimation method for quantifying translocator protein binding with [F]FEPPA positron emission tomography.

Background: The purpose of this study was to assess the feasibility of using a minimally invasive simultaneous estimation method (SIME) to quantify the binding of the 18-kDa translocator protein tracer [F]FEPPA. Arterial sampling was avoided by extracting an image-derived input function (IDIF) that was metabolite-corrected using venous blood samples. The possibility of reducing scan duration to 90 min from the recommended 2-3 h was investigated by assuming a uniform non-displaceable distribution volume (V) to simplify the SIME fitting.

Historical efforts to develop Tc-based amyloid plaque targeting radiotracers.

Imaging biomarkers have changed the way we study Alzheimer's disease and related dementias, develop new therapeutics to treat the disease, and stratify patient populations in clinical trials. With respect to protein aggregates comprised of amyloid-β plaques and tau neurofibrillary tangles, Positron Emission Tomography (PET) has become the gold standard imaging modality for quantitative visualization. Due to high infrastructural costs, the availability of PET remains limited to large urban areas within high income nations.

The functional and structural associations of aberrant microglial activity in major depressive disorder.

Background: Major depressive disorder (MDD) is a debilitating mental illness that has been linked to increases in markers of inflammation, as well as to changes in brain functional and structural connectivity, particularly between the insula and the subgenual anterior cingulate cortex (sgACC). In this study, we directly related inflammation and dysconnectivity in treatment-resistant MDD by concurrently measuring the following: microglial activity with [F]N-2-(fluoroethoxyl)benzyl-N-(4phenoxypyridin-3-yl)acetamide ([F]FEPPA) positron emission tomography (PET); the severity of MDD; and functional or structural connectivity among insula or sgACC nodes.

Methods: Twelve patients with treatment-resistant MDD (8 female, 4 male; mean age ± standard deviation 54.

Low cost and open source purification apparatus for GMP [N]Ammonia production.

Nitrogen-13 labeled ammonia ([N]NH) has been used for myocardial perfusion imaging with Positron Emission Tomography for decades. Recent increases to regulatory oversight have led to stricter adherence to Good Manufacturing Practice (GMP) when producing this short half-life (9.97 min) radiopharmaceutical.

Noninvasive Quantification of Cerebral Blood Flow Using Hybrid PET/MR Imaging to Extract the [ O]H O Image-Derived Input Function Free of Partial Volume Errors.

Background: Quantification of cerebral blood flow (CBF) with [ O]H O-positron emission tomography (PET) requires arterial sampling to measure the input function. This invasive procedure can be avoided by extracting an image-derived input function (IDIF); however, IDIFs are sensitive to partial volume errors due to the limited spatial resolution of PET.

Purpose: To present an alternative hybrid PET/MR imaging of CBF (PMRFlow ) that uses phase-contrast (PC) MRI measurements of whole-brain (WB) CBF to calibrate an IDIF extracted from a WB [ O]H O time-activity curve.

Concordance of regional hypoperfusion by pCASL MRI and O-water PET in frontotemporal dementia: Is pCASL an efficacious alternative?

Background: Clinical diagnosis of frontotemporal dementia (FTD) remains a challenge due to the overlap of symptoms among FTD subtypes and with other psychiatric disorders. Perfusion imaging by arterial spin labeling (ASL) is a promising non-invasive alternative to established PET techniques; however, its sensitivity to imaging parameters can hinder its ability to detect perfusion abnormalities.

Purpose: This study evaluated the similarity of regional hypoperfusion patterns detected by ASL relative to the gold standard for imaging perfusion, PET with radiolabeled water (O-water).

A Noninvasive Method for Quantifying Cerebral Metabolic Rate of Oxygen by Hybrid PET/MRI: Validation in a Porcine Model.

The gold standard for imaging the cerebral metabolic rate of oxygen (CMRO) is positron emission tomography (PET); however, it is an invasive and complex procedure that also requires correction for recirculating O-HO and the blood-borne activity. We propose a noninvasive reference-based hybrid PET/magnetic resonance imaging (MRI) method that uses functional MRI techniques to calibrate O-O-PET data. Here, PET/MR imaging of oxidative metabolism (PMROx) was validated in an animal model by comparison to PET-alone measurements.

Do Self-Reported Drug Allergies Influence Clinically Significant Outcome Improvement Following Osteochondral Allograft Transplantation? A Nested Cohort Study.

Objective: To compare clinical outcomes for patients who underwent osteochondral allograft transplantation (OCA) based on the presence or absence of one or more self-reported drug allergies.

Design: Prospective data were collected from 245 consecutive patients after OCA of the knee from one large academic institution. Patient-reported allergies were obtained via chart review.

Plasma radio-metabolite analysis of PET tracers for dynamic PET imaging: TLC and autoradiography.

Background: In molecular imaging with dynamic PET, the binding and dissociation of a targeted tracer is characterized by kinetics modeling which requires the arterial concentration of the tracer to be measured accurately. Once in the body the radiolabeled parent tracer may be subjected to hydrolysis, demethylation/dealkylation and other biochemical processes, resulting in the production and accumulation of different metabolites in blood which can be labeled with the same PET radionuclide as the parent. Since these radio-metabolites cannot be distinguished by PET scanning from the parent tracer, their contribution to the arterial concentration curve has to be removed for the accurate estimation of kinetic parameters from kinetic analysis of dynamic PET.

Validation protocol for current good manufacturing practices production of [15O]water for hybrid PET/MR studies.

Introduction: Oxygen-15 (O; t½ = 122.4 s) has been used for nuclear imaging experiments since the beginning of the field. With the advent of simultaneous hybrid PET/MR technology, [O]water has seen a resurgence and remains the gold standard method for quantitative blood flow studies.

Effects of tissue culture on the biomechanical properties of porcine meniscus explants.

Background: The meniscus is critical for the normal functioning of the knee joint. The specific aim of this study was to validate an in vitro culture model of meniscus explants for testing the impact of culture conditions on meniscus biomechanical properties. We hypothesized that culturing menisci in the presence of intermediate and high concentration of serum would have a positive effect on the compressive stiffness of the meniscus.

Biologic Adjuvants for the Management of Osteochondral Lesions of the Talus.

Surgical techniques for the management of recalcitrant osteochondral lesions of the talus have improved; however, the poor healing potential of cartilage may impede long-term outcomes. Repair (microfracture) or replacement (osteochondral transplants) is the standard of care. Reparative strategies lead to production of fibrocartilage, which, compared with the native type II articular cartilage, has decreased mechanical and wear properties.

Customized platelet-rich plasma with transforming growth factor β1 neutralization antibody to reduce fibrosis in skeletal muscle.

Unlabelled: The formation of fibrous tissue during the healing of skeletal muscle injuries leads to incomplete recovery of the injured muscle. Platelet-rich-plasma (PRP) contains beneficial growth factors for skeletal muscle repair; however, it also contains deleterious cytokines and growth factors, such as TGF-β1, that can cause fibrosis and inhibit optimal muscle healing.

Objective: To test if neutralizing TGF-β1's action within PRP, through neutralization antibodies, could improve PRP's beneficial effect on skeletal muscle repair.