ABSTRACT PURPOSE: To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats. METHODS: Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test. RESULTS: Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation. CONCLUSION: Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.

PURPOSE: To describe a new experimental flap for studying skin viability in rats.METHODS: Twenty male Wistar rats weighing between 250-300g were divided into two groups: group A - McFarlane technique, a 4 x 10cm flap was used (McFarlane); and in group B modified McFarlane technique, a 3 x 10cm flap was used. Seven days later, the animals were sacrificed and the area of necrosis was evaluated in both groups.RESULTS: Group A presented necrosis in 3% of the total area of the flap (CI: 0.01-0.05), Group B presented necrosis in 37% of the total area of the flap (CI: 0.29-0.46), (p<0.001).CONCLUSION: The modified McFarlane flap presented a larger area of necrosis and could be an adequate experimental model of skin flap viability.