Fracture of the scapular neck sustained in an arm wrestling match.

The sport of arm wrestling requires very little equipment, and can take place anywhere a flat surface is available. As such, undertrained participants often compete, with inevitable injury. Humeral fractures, and elbow injuries are well described, but scapular fractures have not previously been reported in the literature.

Carpal tunnel release using local anaesthetic and a forearm tourniquet.

Carpal tunnel release can be performed under general or local anaesthetic. However, many surgeons believe the upper arm tourniquet is not tolerated by the patient when awake. We use a forearm tourniquet for carpal tunnel decompression under local anaesthesia. The aim of this study is to assess patient tolerance of the technique. Between January 1st 1996 and December 31st 2000, 74 patients had carpal tunnel release performed using local anaesthesia. We sent a postal questionnaire to each, asking the patient to rate different aspects of the procedure. Fifty-eight patients replied (78% response). Forty-four of the respondents (76%) tolerated the tourniquet well, finding it to be 'no problem' or only 'mildly painful'. The same number reported they would prefer to have local anaesthesia again in the event of their requiring a similar operation on their hand. We believe carpal tunnel release using local anaesthetic and a forearm tourniquet is well tolerated by the patient.

Metabolism of styrene by mouse and rat isolated lung cells.

Styrene is pneumotoxic in mice. It is metabolized by pulmonary microsomes of both mouse and rat to styrene oxide (SO), presumed to be the toxic metabolite of styrene, and known to be genotoxic. To determine which pulmonary cell types are responsible for styrene metabolism, and which cytochromes P450 are associated with the bioactivation of styrene, we isolated enriched fractions of mouse and rat Clara and type II cells in order to determine the rate of styrene metabolism, with and without chemical inhibitors. Mouse Clara cells readily metabolized styrene to SO. Diethyldithiocarbamate, a CYP2E1 inhibitor, caused less inhibition of SO formation in Clara cells isolated from mice than previously found with pulmonary microsomes. As in microsomes, 5-phenyl-1-pentyne, a CYP2F2 inhibitor, inhibited the formation of both enantiomers. alpha-Naphthoflavone, a CYP1A inhibitor, did not inhibit SO formation in Clara cells. alpha-Methylbenzylaminobenzotriazole, a CYP2B inhibitor, exhibited minimal inhibition of SO production at 10 microM and less at 1 microM. The microsomal and isolated cell studies indicate that CYP2E1 and CYP2F2 are the primary cytochromes P450 involved in pulmonary styrene metabolism. Styrene metabolizing activity was much greater in Clara cells than in type II pneumocytes, which demonstrated essentially no activity. Styrene-metabolizing activity was several-fold higher in the mouse than in rat Clara cells. The more pneumotoxic and genotoxic form, R-SO, was preferentially formed in mice, and S-SO was preferentially formed in rats. These findings indicate the importance of Clara cells in styrene metabolism and suggest that differences in metabolism may be responsible for the greater susceptibility of the mouse to styrene-induced toxicity.

Effects of inhibitors of CYP1A and CYP2B on styrene metabolism in mouse liver and lung microsomes.

Much of the toxicity of styrene is associated with its bioactivation to styrene oxide. Both liver and lung have been shown to carry out this metabolic step, but there are differences reported as to which isomers of cytochrome P450 are responsible for this biotransformation in various species and tissues. CYP2E1, CYP2F, CYP2B, CYP1A1/2 and CYP2C11 have all been implicated. In the current study, alpha-naphthoflavone (alphaNF) and alpha-methylbenzylaminobenzotriazole (MBA), selective inhibitors of CYP1A and CYP2B, were used to ascertain the contributions of these isomers to styrene metabolism in mouse hepatic and pulmonary microsomes. AlphaNF did not inhibit styrene metabolism with microsomal preparations from either tissue. This indicates that CYP1A is unimportant in the metabolism of styrene to styrene oxide. MBA at a very low concentration of 1 microM inhibited the hepatic metabolism of benzyloxyresorufin (a CYP2B substrate) by 87% but caused only a 16 to 19% inhibition of R- and S-styrene oxide formation. This demonstrates that CYP2B plays a minor role in styrene metabolism. At 10 microM, MBA caused an even greater inhibition of styrene metabolism but at that level it also inhibited p-nitrophenol hydroxylation, a CYP2E1-dependent reaction, suggesting a loss of selectivity for this inhibitor at higher concentrations.

Neurovascular pedicle and advancement flaps for palmar thumb defects.

Thumb injuries are potentially devastating for overall hand function. The aim of surgical reconstruction is to preserve length, restore normal sensibility, and provide an aesthetic, rounded thumb profile. The level and type of thumb injury are most important factors in determining the treatment options for thumb reconstruction. The technical expertise and decision-making skills of the surgeon are of equal significance. With correct management, the majority of patients with these injuries regain excellent functional results.

The bicycle spoke injury: an avoidable accident?

A prospective study of the bicycle spoke injury over a 1-year period included a total of 71 spoke injuries. Of these, 67 injuries occurred on an adult bicycle and four occurred on a child's bicycle. All children sustained ankle and foot injuries, which consisted of contusion and superficial abrasion (N = 45), skin loss (N = 10), skin laceration (N = 4), and undisplaced fractures (N = 12). A biomechanical study was conducted to investigate the use of a protective cover over the wheel to prevent the foot from slipping between the spokes. Wind resistance studies showed that a cover with a mesh size of 10 mm hexagonal could prevent this and at the same time stop the cover from acting as a sail if a flat cover without holes was used instead. The mesh cover, however, will prevent the toes from entering between the spokes but will not prevent the foot from becoming jammed between the wheel and the fork. To prevent this, a plastic shield to bridge the gap between the fork and the horizontal upright has been designed. With these modifications, the bicycle spoke injury can become an injury of the past.