Adductor magnus: a post-operative illustration of its dual nerve supply.

We present a case in which MRI clearly demonstrated the function of the sciatic nerve by highlighting the complications of its involvement by disease and subsequent surgery. In this clinical case, the underlying diagnosis of a nerve sheath tumour had been established and treated surgically, and subsequent follow-up imaging confirmed the expected features of sciatic nerve transection. Six months following the removal of the tumour, atrophy was seen in the muscle groups supplied by the branches of this nerve. This was manifested as muscle wasting and high signal on T1 and T2-weighted MRI affecting the biceps femoris (short and long heads), semimembranosus, semitendinosus, and the hamstring (ischiocondylar) part of the adductor magnus, but the adductor part of the adductor magnus, supplied by the obturator nerve, was spared and appeared normal.