OBJECTIVE AND IMPORTANCE: Intradural or intraradicular herniation of a
lumbar disc is a rave complication of disc disease. The mechanism of
the tearing of the dura mater by a herniated disc is not known with ce
rtainty. Only six cases of intraradicular disc herniation have been re
ported. By reporting the seventh case of this rare neurosurgical entit
y, we emphasize its importance and review the literature on intraradic
ular disc herniation. CLINICAL PRESENTATION: A 41-year-old man was adm
itted with a 3-year history of low back pain and sciatica. A neurologi
cal examination revealed motor weakness during plantar flexion, positi
ve Lasegue's sign, sensory deficit on the S1 dermatoma, and loss of Ac
hilles reflex. Magnetic resonance imaging revealed disc protrusion at
the L5-S1 level. Therefore, we decided to operate on the patient havin
g made a diagnosis of lumbar disc disease. INTERVENTION: The patient u
nderwent a standard hemilaminotomy and foraminotomy for a removal of t
he L5-S1 disc. There was no disc protrusion or extruded fragment. The
left S1 nerve root was observed to be swollen and immobile. A longitud
inal incision was made on the radicular sheet of the S1 root, and a fr
ee disc fragment, approximately 2 x 1 x 1 cm, was extirpated in one pi
ece, CONCLUSION: The patient was immediately relieved of pain and was
discharged on the 7th day after the operation with normal muscle stren
gth. It seems probable that in some patients with ''failed back syndro
me,'' intraradicular or intradural disc herniation is the cause of fai
lure.