Evaluation, Treatment, and Outcomes of Batter's Shoulder.

PURPOSE OF REVIEW: This article reviews the incidence of batter's shoulder, the relevant biomechanics that predispose the lead shoulder to a posterior instability event, the evaluation and workup of posterior labral injury, the surgical technique for arthroscopic posterior labral repair, the postoperative rehabilitation process, and the clinical outcomes and return to sport after treatment of batter's shoulder. RECENT FINDINGS: New epidemiological studies have demonstrated the relatively low incidence of batter's shoulder at the professional baseball level with 85% of the injured players successfully returning to the sport with nonoperative management. However, recent studies have reinforced the limited historical literature that players requiring surgery are able to return to their prior sport at a high level. Batter's shoulder is a subtype of posterior glenohumeral instability caused by the significant forces experienced by the lead shoulder during the baseball swing. Although an uncommon injury, batter's shoulder is a source of significant time away from competition. In patients who do not improve with nonoperative management, arthroscopic posterior labral repair can reliably return players to sport. Future research studies should consider opportunities for injury prevention.

Upper Extremity Injuries in CrossFit Athletes-a Review of the Current Literature.

PURPOSE OF REVIEW: Cross-discipline fitness, or CrossFit, has exploded in popularity during the last two decades. During this time, there have been a high volume of patients presenting to clinicians with a wide range of associated injuries. Given the high intensity, high repetition, and competitive nature of CrossFit training and competition, athletes are vulnerable to injury, particularly upper extremity injury. The rate of injury to the shoulder, elbow, and wrist in CrossFit is higher when compared to traditional weight-training and more comparable to elite-level gymnastics and Olympic-style lifting. Due to the growing popularity of CrossFit-style exercise and the relatively high rate of injury among its participants, clinicians are likely to encounter these athletes. The purpose of this review is to familiarize clinicians with CrossFit and the associated injuries they will likely encounter. RECENT FINDINGS: The medical literature focusing on CrossFit has demonstrated exponential growth, with the first article published in 2012 and 59 articles published in 2020. Although the body of literature is growing, there are no high-level studies focusing on CrossFit. The literature mainly consists of level IV and V studies, primarily consisting of case reports and case series. Recent studies have proven that CrossFit athletes are vulnerable to high rates of upper extremity injury and a few studies have identified risk factors for injury. Future high-level research is required to study modifiable risk factors, diagnostic criteria, and treatment options for these high-risk athletes in order to improve the safety of their sport. The CrossFit body of research is limited to level IV and V studies; however, the literature is clear, CrossFit athletes face a high rate of upper extremity injury. For this reason, clinicians must be familiar with CrossFit and its associated pathology. The goal of this review is to familiarize clinicians with CrossFit and the associated pathologies they will likely encounter.

A novel mouse model of hindlimb joint contracture with 3D-printed casts.

Stiff joints formed after trauma, surgery or immobilization are frustrating for surgeons, therapists and patients alike. Unfortunately, the study of contracture is limited by available animal model systems, which focus on the utilization of larger mammals and joint trauma. Here we describe a novel mouse-based model system for the generation of joint contracture using 3D-printed clamshell casts. With this model system we are able to generate both reversible and irreversible contractures of the knee and ankle. Four- or 8-month-old female mice were casted for either 2 or 3 weeks before liberation. All groups formed measurable contractures of the knee and ankle. Younger mice immobilized for less time formed reversible contractures of the knee and ankle. We were able to generate irreversible contracture with either longer immobilization time or the utilization of older mice. The contracture formation translated into differences in gait, which were detectable using the DigiGait® analysis system. This novel model system provides a higher throughput, lower cost and more powerful tool in studying the molecular and cellular mechanisms considering the large existing pool of transgenic/knockout murine strains.

Water-Soluble Nanoconjugate for Enhanced Cellular Delivery of Receptor-Targeted Magnetic Resonance Contrast Agents.

ProGlo is an efficient steroid receptor-targeted magnetic resonance (MR) imaging contrast agent (CA). It has been shown to bind to the progesterone receptor (PR) and produce enhanced image contrast in PR-positive cells and tissues in vitro and in vivo. However, the hydrophobicity of the steroid targeting domain of ProGlo (logP = 1.4) limits its formulation and delivery at clinically relevant doses. In this work, a hydrophobic moiety was utilized to drive efficient adsorption onto nanodiamond (ND) clusters to form a water-soluble nanoconstruct (logP = -2.4) with 80% release in 8 h under biological conditions. In cell culture, the ND-ProGlo construct delivered increased concentrations of ProGlo to target cells compared to ProGlo alone. Importantly, these results were accomplished without the use of solvents such as DMSO, providing a significant advance toward formulating ProGlo for translational applications. Biodistribution studies confirm the delivery of ProGlo to PR(+) tissues with enhanced efficacy over untargeted controls. These results demonstrate the potential for a noncovalent ND-CA construct as a general strategy for solubilizing and delivering hydrophobic targeted MR CAs.

Nanodiamond-Gadolinium(III) Aggregates for Tracking Cancer Growth In Vivo at High Field.

The ability to track labeled cancer cells in vivo would allow researchers to study their distribution, growth, and metastatic potential within the intact organism. Magnetic resonance (MR) imaging is invaluable for tracking cancer cells in vivo as it benefits from high spatial resolution and the absence of ionizing radiation. However, many MR contrast agents (CAs) required to label cells either do not significantly accumulate in cells or are not biologically compatible for translational studies. We have developed carbon-based nanodiamond-gadolinium(III) aggregates (NDG) for MR imaging that demonstrated remarkable properties for cell tracking in vivo. First, NDG had high relaxivity independent of field strength, a finding unprecedented for gadolinium(III) [Gd(III)]-nanoparticle conjugates. Second, NDG demonstrated a 300-fold increase in the cellular delivery of Gd(III) compared to that of clinical Gd(III) chelates without sacrificing biocompatibility. Further, we were able to monitor the tumor growth of NDG-labeled flank tumors by T1- and T2-weighted MR imaging for 26 days in vivo, longer than was reported for other MR CAs or nuclear agents. Finally, by utilizing quantitative maps of relaxation times, we were able to describe tumor morphology and heterogeneity (corroborated by histological analysis), which would not be possible with competing molecular imaging modalities.

Diamond-lipid hybrids enhance chemotherapeutic tolerance and mediate tumor regression.

Self-assembled nanodiamond-lipid hybrid particles (NDLPs) harness the potent interaction between the nanodiamond (ND)-surface and small molecules, while providing a mechanism for cell-targeted imaging and therapy of triple negative breast cancers. Epidermal growth factor receptor-targeted NDLPs are highly biocompatible particles that provide cell-specific imaging, promote tumor retention of ND-complexes, prevent epirubicin toxicities and mediate regression of triple negative breast cancers.

A robust Monte Carlo model for the extraction of biological absorption and scattering in vivo.

We have a toolbox to quantify tissue optical properties that is composed of specialized fiberoptic probes for UV-visible diffuse reflectance spectroscopy and a fast, scalable inverse Monte Carlo (MC) model. In this paper, we assess the robustness of the toolbox for quantifying physiologically relevant parameters from turbid tissue-like media. In particular, we consider the effects of using different instruments, fiberoptic probes, and instrument-specific settings for a wide range of optical properties. Additionally, we test the quantitative accuracy of the inverse MC model for extracting the biologically relevant parameters of hemoglobin saturation and total hemoglobin concentration. We also test the effect of double-absorber phantoms (hemoglobin and crocin to model the absorption of hemoglobin and beta carotene, respectively, in the breast) for a range of absorption and scattering properties. We include an assessment on which reference phantom serves as the best calibration standard to enable accurate extraction of the absorption and scattering properties of the target sample. We found the best reference-target phantom combinations to be ones with similar scattering levels. The results from these phantom studies provide a set of guidelines for extracting optical parameters from clinical studies.