The Application of Advanced Bone Imaging Technologies in Sports Medicine.

Until recently, the evaluation of bone health and fracture risk through imaging has been limited to dual-energy X-ray absorptiometry (DXA) and plain radiographs, with a limited application in the athletic population. Several novel imaging technologies are now available for the clinical assessment of bone health, including bone injury risk and healing progression, with a potential for use in sports medicine. Among these imaging modalities is high-resolution peripheral quantitative computed tomography (HR-pQCT) which is a promising technology that has been developed to examine the bone microarchitecture in both cortical and trabecular bone at peripheral anatomical sites. Technologies that do not expose patients to ionizing radiation are optimal, particularly for athletes who may require frequent imaging. One such alternative is diagnostic ultrasound, which is preferable due to its low cost and lack of radiation exposure. Furthermore, ultrasound, which has not been a common imaging modality for monitoring fracture healing, has been shown to potentially demonstrate earlier signs of union compared to conventional radiographs, including callus mineralization and density at the healing site. Through the use of conventional magnetic resonance imaging (MRI), finite element analysis (FEA) can be used to simulate the structural and mechanical properties of bone. On the other hand, the ultrashort echo time (UTE) MRI can evaluate cortical bone quality by detecting water bound to the organic bone matrix and free water, providing important information about bone porosity. Several novel bone imaging techniques originally developed for osteoporosis assessment have great potential to be utilized to improve the standard of care in bone fracture risk assessment and healing in sports medicine with much greater precision and less adverse radiation exposure.

Management of congenital nasolacrimal duct obstruction in down syndrome.

BACKGROUND: Congenital nasolacrimal duct obstruction (CNLDO) is common in Down Syndrome (DS), and more difficult to treat. Our purpose was to describe the management of CNLDO in paediatric patients with DS. METHODS: Retrospective cohort study. Medical chart review of all DS patients diagnosed with CNLDO at the Division of Ophthalmology at the Children's Hospital of Philadelphia during a 12-year period (2009-2020). Main outcome measures included: Surgical interventions, primary probing outcome, rate of dacryocystorhinostomy (DCR) and/or conjunctivodacryocystorhinostomy (CDCR), and overall success. RESULTS: 126 patients (236 eyes) were included, mean age of 1.8 ± 2.1 years (range 0.1-11.3 y), 110 (87%) had bilateral CNLDO. Mean follow-up time was 41 months. 84 patients (67%) underwent at least one surgical intervention; the mean number of surgical interventions in this group was 1.8 ± 1.4 per patient (range, 1-6). The most common primary intervention was probing (n = 74, 88%), mostly (n = 57, 68%) with monocanalicular silicone intubation. Probing with silicone intubation had a higher success rate compared to probing alone (P = 0.002). Twenty (24% of 84) patients underwent DCR/CDCR during the follow-up period. Complete resolution was achieved in 123 patients (98%). CONCLUSIONS: CNLDO in Down syndrome is associated with high rates of bilateral obstructions and with less favourable surgical outcomes. Many patients ultimately require a more robust surgical intervention such as DCR or CDCR. The use of monocanalicular stent in initial probing was associated with a higher success rate, and would appear to be appropriate in all CNLDO-DS cases.

Orbital and periorbital dermoid cysts: a retrospective analysis of 270 lesions.

PURPOSE: To report the clinical characteristics and intraoperative findings of periorbital and orbital dermoid cysts and their relationship to location and rupture. METHODS: Retrospective review of 270 cases with orbital or periorbital dermoid cysts that presented over a period of 11 years. Patients were included if diagnosis of dermoid cyst was made by histopathologic analysis. Clinical characteristics and operative outcomes were recorded and analyzed with Chi-squared analyses or univariate regression. Multivariate binary logistic regression was performed to assess predictors of location and rupture. RESULTS: Dermoids frequently occurred unilaterally and were more frequently described as mobile (61.5%), followed by fixed (30.8%), and partially fixed (7.7%). Dermoid rigidity was most commonly described as firm (75.5%), followed by cystic, soft, and rubbery. The most common dermoid location was superotemporal (60.4%). On Chi-squared analysis, superotemporal lesions were less likely to have orbital extension than non-superotemporal lesions (OR 0.28, 95% CI: 0.11-0.70, p = .01), less likely to undergo CT (OR 0.16, 95% CI: 0.06-0.41, p < .01) or MRI (OR 0.23, 95% CI: 0.13-0.41, p < .01), more likely to be described as mobile (OR 2.91, 95% CI: 1.32-6.43, p = .01), and less likely to rupture intraoperatively (OR 0.28, 95% CI: 0.11-0.73, p = .01). No variables were associated with rupture in multivariate analysis. CONCLUSION: Superotemporal dermoid cysts are common in the pediatric population, less likely to have orbital extension, undergo imaging, and have intraoperative rupture when compared to other locations in the orbit.

The Effect of Inflammation on Bone.

Bone remodeling is the continual process to renew the adult skeleton through the sequential action of osteoblasts and osteoclasts. Nuclear factor RANK, an osteoclast receptor, and its ligand RANKL, expressed on the surface of osteoblasts, result in coordinated control of bone remodeling. Inflammation, a feature of illness and injury, plays a distinct role in skewing this process toward resorption. It does so via the interaction of inflammatory mediators and their related peptides with osteoblasts and osteoclasts, as well as other immune cells, to alter the expression of RANK and RANKL. Such chemical mediators include TNFα, glucocorticoids, histamine, bradykinin, PGE2, systemic RANKL from immune cells, and interleukins 1 and 6. Conditions, such as periodontal disease and alveolar bone erosion, aseptic prosthetic loosening, rheumatoid arthritis, and some sports related injuries are characterized by the result of this process. A thorough understanding of bone response to injury and disease, and ability to detect such biomarkers, as well as imaging to identify early structural and mechanical property changes in bone architecture, is important in improving management and outcomes of bone related pathology. While gut health and vitamin and mineral availability appear vitally important, nutraceuticals also have an impact on bone health. To date most pharmaceutical intervention targets inflammatory cytokines, although strategies to favorably alter inflammation induced bone pathology are currently limited. Further research is required in this field to advance early detection and treatments.

Ndfip1 restricts mTORC1 signalling and glycolysis in regulatory T cells to prevent autoinflammatory disease.

Foxp3+ T regulatory (Treg) cells suppress immune cell activation and establish normal immune homeostasis. How Treg cells maintain their identity is not completely understood. Here we show that Ndfip1, a coactivator of Nedd4-family E3 ubiquitin ligases, is required for Treg cell stability and function. Ndfip1 deletion in Treg cells results in autoinflammatory disease. Ndfip1-deficient Treg cells are highly proliferative and are more likely to lose Foxp3 expression to become IL-4-producing TH2 effector cells. Proteomic analyses indicate altered metabolic signature of Ndfip1-deficient Treg cells and metabolic profiling reveals elevated glycolysis and increased mTORC1 signalling. Ndfip1 restricts Treg cell metabolism and IL-4 production via distinct mechanisms, as IL-4 deficiency does not prevent hyperproliferation or elevated mTORC1 signalling in Ndfip1-deficient Treg cells. Thus, Ndfip1 preserves Treg lineage stability and immune homeostasis by preventing the expansion of highly proliferative and metabolically active Treg cells and by preventing pathological secretion of IL-4 from Treg cells.