A biomechanical analysis of plate fixation using unicortical and bicortical screws in transverse metacarpal fracture models subjected to 4-point bending and dynamical bending test.

In the published literature there are controversial data to the biomechanical stability of monocortical comparing to the bicortical fixation of metacarpal fractures. The aim of this study was to compare the biomechanical stability of monocortical and bicortical locking osteosynthesis in quasi-static and dynamic 4-point bending tests of composite third metacarpal bone (4th Gen third metacarpal, Sawbones, Malmö, Sweden) fixed with 7-hole locking plate (XXS System, Biotech-Ortho, Wright, Memphis, TN). The tests to determine quasi-static yield and bending strength as well as fatigue strength were conducted in 4 groups of 10 samples after creating standardized mid-shaft transverse osteotomies using a diamont belt grinder (0.3 mm saw blade). The force applied was the dorsal apex loading, similar to the forces applied to metacarpals during normal finger flexion and extension.In the quasi-static testing, no plate breakage was observed in each group. All metacarpals broke at their thinnest part. The average bending strength of the bicortical samples (10.54 ±â€Š0.998 Nm) was significantly higher comparing to the monocortical samples (8.57 ±â€Š0.894 Nm) (P < .001).In the dynamic loading test, all constructs (8 monocortical samples and 7 bicortical) that failed broke at the osteotomy site and the average fatigue strength did not differ in both groups.Consequently, a unicortical plating method may provide adequate strength and stability to metacarpal fractures based on the results of the cyclical loading representative of in vivo loading.

Prophylactic antibiotic therapy after inhalation injury.

OBJECTIVE: Inhalation injury is suspected in patients with facial and neck burn-injuries and in patients who suffered burns in an enclosed space. Inhalation injury is associated with a disappointingly high morbidity and mortality in spite of advances in diagnostics and therapy.Prophylactic antibiotic therapy in patients with diagnosed inhalation injury is still a controversial subject.The epidemiologic characteristics of the burn patients with diagnosed inhalation injury in our clinic receiving prophylactic antibiotic therapy and mortality of these patients will be referred in this study. METHODS: Patients >16 years of age admitted to the burn unit between January 2008 and December 2012 and fulfilling the burn center referral criteria according the German Burn Association were enrolled in the study. RESULTS: 58 patients (male:female 47:11) were diagnosed with an inhalation injury by their admission. The average length of hospital stay was 27.5 days, whereas of the patients with no inhalation injury was 16 days (p=0.04). 56.9% of the patients underwent tracheostomy. An escalation of the antibiotic therapy was done in 39.7% of the patients with inhalation injury and in 20.3% of the patients without one. The mortality of inhalation injury patients was 12.1%. CONCLUSIONS: The development of pneumonia is not influenced in a statistical significant way by the use of prophylactic antibiotics. We do recommend the administration of prophylactic antibiotic therapy to patients with diagnosed inhalation trauma, as the mortality of these patients was lower in comparison to other studies.