Cast Immobilisation versus Wire Fixation in the Management of Middle-aged and Elderly Patients with Distal Radius Fractures.

BACKGROUND: Distal radius fractures are common and traditionally these injuries are treated non-operatively. Percutaneous wiring has been recommended as simple method to provide extra stability in distal radius fractures but their exact role is uncertain. The aim of this study was to retrospectively compare the radiographic and functional outcomes following cast immobilisation and those following wire fixation in the management of distal radius fractures and investigate which method produced better outcomes. METHODS: A retrospective parallel case series was performed between April 2011 and April 2013 of patients over 50 years treated with either cast immobilisation or wire fixation. Both intra- and extra-articular fractures were included. Radiographic measurements were made pre-operatively and at three months follow up. The QuickDASH was recorded by postal questionnaire at a mean of 2 years. RESULTS: 159 patients were included; 85 cast immobilisation group and 74 wire fixation group. Improvement in radiological parameters was seen in both groups but this was significantly better after wire fixation ([Formula: see text]). QuickDASH scores were available in 64%; no significant difference in mean scores was seen after (p = 0.147); cast immobilisation 27.1 and wire fixation 26.6. CONCLUSIONS: Cast immobilisation can produce comparable functional results to wire fixation despite worse radiological outcomes.

TRPA1 insensitivity of human sural nerve axons after exposure to lidocaine.

TRPA1 is an ion channel of the TRP family that is expressed in some sensory neurons. TRPA1 activity provokes sensory symptoms of peripheral neuropathy, such as pain and paraesthesia. We have used a grease gap method to record axonal membrane potential and evoked compound action potentials (ECAPs) in vitro from human sural nerves and studied the effects of mustard oil (MO), a selective activator of TRPA1. Surprisingly, we failed to demonstrate any depolarizing response to MO (50, 250 µM) in any human sural nerves. There was no effect of MO on the A wave of the ECAP, but the C wave was reduced at 250 µM. In rat saphenous nerve fibres MO (50, 250 µM) depolarized axons and reduced the C wave of the ECAP but had no effect on the A wave. By contrast, both human and rat nerves were depolarized by capsaicin (0.5 to 5 µM) or nicotine (50 to 200 µM). Capsaicin caused a profound reduction in C fibre conduction in both species but had no effect on the amplitude of the A component. Lidocaine (30 mM) depolarized rat saphenous nerves acutely, and when rat nerves were pretreated with 30 mM lidocaine to mimic the exposure of human nerves to local anaesthetic during surgery, the effects of MO were abolished whilst the effects of capsaicin were unchanged. This study demonstrates that the local anaesthetic lidocaine desensitizes TRPA1 ion channels and indicates that it may have additional mechanisms for treating neuropathic pain that endure beyond simple sodium channel blockade.