To expose the sciatic nerve, retract the long head of the biceps femoris muscle laterally. As the sciatic nerve is cleaned, identify its muscular branches. The sciatic nerve has previously been dissected in the gluteal region and its course has been identified. In the proximal portion of the posterior compartment of the thigh, the sciatic nerve [the upper probe indicates the sciatic nerve; the retractor holds the biceps femoris muscle] passes deep to the long head of the biceps femoris muscle. Distally, the sciatic nerve lies between the biceps femoris muscle and the semimembranosus and semitendinosus muscles.
As the muscular branches of the sciatic nerve are identified, also locate the blood vessels to the hamstrings, which are primarily from the perforating branches of the profunda femoris artery.
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