Biomechanical and safety testing of a simplified negative-pressure wound therapy device.

BACKGROUND: There is a large, unmet need for acute and chronic wound care worldwide. Application of proven therapies such as negative-pressure wound therapy in resource-constrained settings is limited by cost and lack of electrical supply. To provide an alternative to existing electrically powered negative-pressure wound therapy systems, a bellows-powered negative-pressure wound therapy system was designed and iteratively improved during field-based testing. The authors describe the design process and the results of safety and biomechanical testing of their simplified negative-pressure wound therapy system. METHODS: Simplified negative-pressure wound therapy was tested at two hospitals in Rwanda. Patients with wounds ranging from 2 to 150 cm and meeting inclusion and exclusion criteria were enrolled. Wounds were categorized by difficulty of dressing application according to location and contour. Outcomes were maintenance of negative pressure and occurrence of adverse events. RESULTS: Thirty-seven patients with 42 wounds were treated with simplified negative-pressure wound therapy. Eighty-five dressings in total were applied. On average, the final simplified negative-pressure wound therapy dressing maintained negative pressure for 31.7 hours on all wounds (n = 37), and 52.7 hours on wounds in easy-to-dress locations. No unexpected adverse events occurred. CONCLUSIONS: This is the first systematic report of the performance of a bellows-powered negative-pressure wound therapy device designed specifically for use in resource-constrained settings. The authors found that elimination of air leaks in the simplified negative-pressure wound therapy dressing is essential, and that their system is safe and feasible for use in these environments. Subsequent trials will study the system's efficacy.

Innervation of the elbow joint: Is total denervation possible? A cadaveric anatomic study.

The aim of this anatomical study was to find out if total denervation of the elbow joint is technically feasible. The endbranches of the brachial plexus of eight fresh-frozen upper arm cadavers were dissected with optical loupe magnification. All major nerves of the upper limb (except the axillary and the medial brachial cutaneous nerve) give some terminal articular endbranches to the elbow. The articular endbranches arise from muscular endbranches, cutaneous endbranches, or arise straight from the main nerves of the brachial plexus. A topographic diagram was made of the different nerves innervating the elbow joint. The ulno-posterior part of the elbow is innervated by the ulnar nerve and some branches of medial antebrachial cutaneous nerve. The radial-posterior part of the elbow is innervated exclusively by the radial nerve. The ulno-anterior part of the elbow is innervated by the median nerve and the musculocutaneous nerve. The radio-anterior part of the elbow is innervated by the radial nerve and the musculocutaneous nerve. These elbow innervation findings are relevant to both anatomical and clinical field as they provide evidence that the total denervation of the elbow joint is impossible. Nevertheless, partial denervation, like denervation of the lateral epicondyle or the ulnar part of elbow, is technically possible.