Intraoperative straight-leg raising during laminectomy and disk excision for sciatica.

During lumbar disk excision for sciatica, doubts may occasionally arise as to the level of the lesion or the degree of involvement of the particular nerve root being observed. Following removal of the obstructing agent, can we be certain that liberation of the nerve root is complete? These anxieties can be dispelled by performing a straight-leg raising test bilaterally during the operation both before and after removal of the obstructing agent. The intraoperative straight-leg raising tests enable observations to be made as to the degree of nerve tension on the involved side as compared with tension on the uninvolved side; at the end of the operation, the tension on the involved side should be no more than the tension on the uninvolved side. When the straight-leg raising test is not being performed, it should be possible for the nerve root to be displaced to the midline of the spinal canal with ease.