A Histological and Clinical Study of MatriDerm® Use in Burn Reconstruction.

Dermal substitutes are well established in the reconstructive ladder. MatriDerm® (Dr. Otto Suwelack Skin & Health Care AG, Billerbeck, Germany) is a single-layer dermal substitute composed of a bovine collagen (type I, III, and V) and elastin hydrolysate, that allows for immediate split-thickness skin grafting (SSG). The aim of this study was to histologically characterize the integration of MatriDerm® when used during burns surgery reconstruction. Eight subjects with nine burn scars and one acute burn wound underwent reconstruction with MatriDerm® and an immediate SSG. MatriDerm® integration and skin graft take were assessed with serial biopsies performed at weeks 1, 2, 3, and 4 and months 2, 3, 6, 9, and 12. Biopsies were assessed with standard special stains and immunohistochemistry, and representative slides were imaged with a transmission electron microscope. Patient satisfaction and clinical scar outcome were assessed with the Vancouver Scar Scale and a patient questionnaire. Histological analysis showed similar stages of wound healing as shown in other dermal templates but on a different timescale. There is early evidence of vascularization and an inflammatory infiltrate in the first 2 weeks. MatriDerm® is resorbed earlier than other dermal substitutes, with evidence of resorption at week 3, to be completely replaced by a neodermis at 2 months. The use of MatriDerm® in reconstruction with immediate skin grafting is supported histologically with early evidence of vascularization to support an epidermal autograft. Future histological studies may help further characterize the ideal dermal substitute.

Structuring of Hydrogels across Multiple Length Scales for Biomedical Applications.

The development of new materials for clinical use is limited by an onerous regulatory framework, which means that taking a completely new material into the clinic can make translation economically unfeasible. One way to get around this issue is to structure materials that are already approved by the regulator, such that they exhibit very distinct physical properties and can be used in a broader range of clinical applications. Here, the focus is on the structuring of soft materials at multiple length scales by modifying processing conditions. By applying shear to newly forming materials, it is possible to trigger molecular reorganization of polymer chains, such that they aggregate to form particles and ribbon-like structures. These structures then weakly interact at zero shear forming a solid-like material. The resulting self-healing network is of particular use for a range of different biomedical applications. How these materials are used to allow the delivery of therapeutic entities (cells and proteins) and as a support for additive layer manufacturing of larger-scale tissue constructs is discussed. This technology enables the development of a range of novel materials and structures for tissue augmentation and regeneration.

Isolated Dorsoradial Capsular Tear of the Thumb Metacarpophalangeal Joint: Missed Diagnosis and the Management of Delayed Presentation.

Isolated dorsoradial capsule injuries of the thumb metacarpophalangeal joint are different from those associated with collateral ligament disruption. Early suspicion of this rare injury is important because, if overlooked, ulnarward subluxation of extensor pollicis longus tendon can develop. Functionally, active thumb extension becomes impaired, and over the long term, a thumb Boutonniere's deformity becomes established. Joint hypermobility/instability may predispose to this injury. The 2 cases presented illustrate this through anatomic differences. At the time of acute injury, 3 presenting clinical features should raise suspicion of dorsoradial capsular rupture: a history of isolated hyperflexion injury to the thumb, stable collateral ligaments on examination, and x-ray evidence of palmar subluxation of the proximal phalanx on the metacarpal. Ulnarward subluxation of the extensor pollicis longus is a delayed sign. Diagnostic imaging, beyond x-ray studies, may not be helpful in defining the injury. Early exploration and repair of this injury give the best long-term outcome. Postrepair, metacarpophalangeal joint range of motion may not be fully restored, but stability and a preinjury level of hand function can usually be reestablished.

Advances in keratinocyte delivery in burn wound care.

This review gives an updated overview on keratinocyte transplantation in burn wounds concentrating on application methods and future therapeutic cell delivery options with a special interest in hydrogels and spray devices for cell delivery. To achieve faster re-epithelialisation of burn wounds, the original autologous keratinocyte culture and transplantation technique was introduced over 3 decades ago. Application types of keratinocytes transplantation have improved from cell sheets to single-cell solutions delivered with a spray system. However, further enhancement of cell culture, cell viability and function in vivo, cell carrier and cell delivery systems remain themes of interest. Hydrogels such as chitosan, alginate, fibrin and collagen are frequently used in burn wound care and have advantageous characteristics as cell carriers. Future approaches of keratinocyte transplantation involve spray devices, but optimisation of application technique and carrier type is necessary.

Effect of surgical decompression of nerves in the lower extremity in patients with painful diabetic polyneuropathy on stability: a randomized controlled trial.

OBJECTIVE: To investigate the effect of decompression of nerves in the lower extremity in patients with painful diabetic polyneuropathy on static balance using a sensitive pressure mat system. DESIGN: Non-blinded randomized controlled trial. SETTING: Single center study performed at the University Medical Center Utrecht between 2010-2013. SUBJECTS: Patients with painful diabetic polyneuropathy assessed with the Diabetic Neuropathy Symptom score and Diabetic Neuropathy Examination between 18-90 years. Exclusion criteria were: physical problems leading to instability, BMI>35 kg/m2, ankle fractures in history, amputations proximal to the tarsometatarsal joints, active foot ulcer(s), severe occlusive peripheral vascular diseases. INTERVENTION: Unilateral surgical nerve decompression at four sites in the lower extremity, the contralateral limb was used as control (within-patient comparison), with one year follow-up. MAIN MEASURES: Preoperatively and 6 and 12 months postoperatively, weight bearing and five variables of sway of the center of pressure were measured with a pressure mat with eyes open and eyes closed. T-test was used for evaluation of postoperative results. RESULTS: Thirty-nine Patients met inclusion criteria and were enrolled for stability testing. Postoperatively no significant differences for sway variables and weight bearing were seen compared to preoperatively measurements. CONCLUSIONS: There is no evidence that surgical decompression of nerves of the lower extremity influences stability within one year after surgery in patients with painful diabetic polyneuropathy.