Purpose: There are a wide variety of operative procedures for lumbar spinal canal stenosis. Bilateral fenestration, preserving the continuity of the lamina and spinous processes, has widely been employed in our department and its affiliated hospitals. The following questions are raised: Are decompressive effects of fenestration and spinal stability maintained without spinal fusion or instrumentation? In order to answer the questions, we compared the rates of revision after fenestration with those after laminectomy alone and decompressive surgery with spinal fusion.

Materials and methods: The registry of spinal surgeries of our university and affiliated hospitals from 1988 to 1997 was consulted.

During the first 5-years period 1159 patients underwent decompressive surgery. 908 of them had spondylosis and 251 had degenerative spondylolisthesis (DO) as a contributing factors of neural compression. Fenestration was done in 740 (81%) of patients with spondylosis and in 176 (70%) of patients with DO.

Results: Regarding the whole series 31 out of 1159 patients had a revision. The revision rate was 2.7%. 15 out of 908 patients (1.7%) with spondylosis and 16 out of 251 patients (6.4%) with DO underwent revisions. 11 out of 740 (1.5%) with spondylosis and 11 out of 176 (6.3%) with DO underwent revisions after fenestration. No significant differences were found among the revision rate of fenestration, laminectomy and decompressive surgery with spinal fusion.

Conclusion: The decompressive effect of fenestration was maintained long enough, even for degenerative spondylolisthesis. As a first operation spinal fusion is not necessarily indicated for lumbar canal stenosis.

Diagnostic indices for the determination of involved nerve root in cervical radiculopathy have been described by Yoss (1957), Murphey (1973) and Hoppenfeld (1976). However, there has been criticism that their indices are inappropriate for the diagnosis, because involved nerve root can not necessarily be determined using them. Difficulties in diagnosis have been attributed to the variable patterns of symptoms and signs caused by nerve root compression.

Purpose: To develop the new diagnostic indices for determination of involved nerve root in cervical radiculopathy.

Methods: Forty-five cases operated on through posterior foraminotomy were reviewed. The sites of neck pain(s) (in nape, in suprascapular, superior angle of scapula, interscapular, or scapular regions), and arm pain (anterior, lateral, posterior or medial) in anatomical position were preoperatively recorded. The finger(s) with subjective paraesthesia or objective sensory change, and the finger(s) of the most severe involvement were recorded. Affected muscle(s) (deltoid, biceps, wrist extensor, wrist flexor, triceps, finger extensor, or intrinsic), and the muscle(s) of the weakest were recorded. All of 45 cases were decompressed unilaterally at only 1 level, and showed improvements just after operation. Involved nerve roots and number of their cases were as follows: C5, 7; C6, 12; C7, 13; C8, 13.

Results: Pain in the suprascapular region frequently (82%) indicated C5 or C6 radiculopathy. Interscapular or scapular pain always (100%) indicated C7 or C8 radiculopathy. Lateral, posterior, or medial arm pain frequently indicated C6, C7 or C8 radiculopathy, respectively. Involved nerve roots and number of patterns of finger paraesthesia [or sensory change] were as follows: C5, 0 [0]; C6, 4 [5]; C7, 8 [10]; C8, 4 [5]. However, when the most severe involvement was that of the thumb, the index or long finger, or the little finger, the indication was C6, C7 or C8 radiculopathy, respectively. Although patterns in affection of muscles were also variable, when the weakest muscle was deltoid, biceps or wrist extensor, wrist flexor or triceps, or intrinsic, the indication was C5, C6, C7 or C8 radiculopathy, respectively.

Conclusion: The sites of the neck and arm pain are important for the diagnosis of the involved nerve root. Not the fingers with paraesthesia but the fingers with the most severe involvement lead to the diagnosis.