Understanding the spectrum of paediatric mechanical finger and hand trauma seeking acute care.

PURPOSE: Paediatric hand injuries are a frequent reason for acute medical evaluation. Previous studies have reported only fracture rates, surgical injuries or are limited to database diagnosis coding. The average fracture rates and injury distributions across the hand for all mechanical injuries have not been well-described. METHODS: We performed a retrospective review of all emergent/urgent care visits over 18 months at a US paediatric tertiary hospital with hand injuries recorded anywhere in the encounter. Patient, injury and encounter details were recorded with additional imaging review, categorized and described. RESULTS: A total of 523 patient visits (0.64% of all encounters) were for mechanical hand trauma. The injury mechanism was 42% crush, 19% jammed, 12% impact, 12% fall on outstretched hand, 7% hyperextension and 8% other/unclear. Crush was responsible for 80% of injuries in patients aged 0 to six years old but only 17% in patients aged 13 to 18 years. Crush resulted in fractures only 26% of the time, while other mechanisms were more likely to fracture (33% to 87%). Border digits were injured more often than others (21% to 23% versus 13% to 17%), and were most commonly fractured in the proximal phalanx (57% to 67% versus 22% to 34% for non-border digits). Providers correctly coded for basic fracture presence in 89.1% of injuries, but 53% of codes were not finger or laterality-specific, and only 15% specified a bony segment demonstrating that International Classification of Diseases-9 coding was nonspecific for injury patterns. CONCLUSION: Patients with paediatric hand injuries frequently utilize emergency care and understanding the basic patterns of injury can guide resource utilization and future studies on optimal treatment algorithms in this setting. LEVEL OF EVIDENCE: IV, Prognostic, Case Series.

Enhancing human islet transplantation by localized release of trophic factors from PLG scaffolds.

Islet transplantation represents a potential cure for type 1 diabetes, yet the clinical approach of intrahepatic delivery is limited by the microenvironment. Microporous scaffolds enable extrahepatic transplantation, and the microenvironment can be designed to enhance islet engraftment and function. We investigated localized trophic factor delivery in a xenogeneic human islet to mouse model of islet transplantation. Double emulsion microspheres containing exendin-4 (Ex4) or insulin-like growth factor-1 (IGF-1) were incorporated into a layered scaffold design consisting of porous outer layers for islet transplantation and a center layer for sustained factor release. Protein encapsulation and release were dependent on both the polymer concentration and the identity of the protein. Proteins retained bioactivity upon release from scaffolds in vitro. A minimal human islet mass transplanted on Ex4-releasing scaffolds demonstrated significant improvement and prolongation of graft function relative to blank scaffolds carrying no protein, and the release profile significantly impacted the duration over which the graft functioned. Ex4-releasing scaffolds enabled better glycemic control in animals subjected to an intraperitoneal glucose tolerance test. Scaffolds releasing IGF-1 lowered blood glucose levels, yet the reduction was insufficient to achieve euglycemia. Ex4-delivering scaffolds provide an extrahepatic transplantation site for modulating the islet microenvironment to enhance islet function posttransplant.

Advancing islet transplantation: from engraftment to the immune response.

The promise and progress of islet transplantation for treating type 1 diabetes has been challenged by obstacles to patient accessibility and long-term graft function that may be overcome by integrating emerging technologies in biomaterials, drug delivery and immunomodulation. The hepatic microenvironment and traditional systemic immunosuppression stress the vulnerable islets and contribute to the limited success of transplantation. Locally delivering extracellular matrix proteins and trophic factors can enhance transplantation at extrahepatic sites by promoting islet engraftment, revascularisation and long-term function while avoiding unintended systemic effects. Cell- and cytokine-based therapies for immune cell recruitment and reprogramming can inhibit local and systemic immune system activation that normally attacks transplanted islets. Combined with antigen-specific immunotherapies, states of operational tolerance may be achievable, reducing or eliminating the long-term pharmaceutical burden. Integration of these technologies to enhance engraftment and combat rejection may help to advance the therapeutic efficacy and availability of islet transplantation.