Microsurgical excision of hematoma of the lumbar ligamentum flavum.

Hematoma of the lumbar ligamentum flavum is a very rare cause of sciatica. A 72-year-old man presented with left-sided sciatica and paresthesia of the lateral aspect of his left foot. From CT and MRI findings, he was diagnosed as having a hematoma embedded in the ligamentum flavum, which compressed the dura mater at the L5/S1 disc level. After an adequate surgical field was obtained with a microscope and a Casper retractor, the hematoma of the ligamentum flavum could be excised via a unilateral approach and satisfactory decompression of the cauda equina and nerve roots were obtained.