Outcomes of posterior fusion using pedicle screw fixation in patients >or=70 years with lumbar spinal canal stenosis.

Pedicle screw fixation is frequently used for spinal fusion in elderly patients. The application of pedicle screw fixation for elderly patients with degenerative lumbar disease remains controversial due to problems such as surgical invasion, osteoporosis, and cost performance. Outcomes of spinal fusion using pedicle screw fixation were evaluated in patients older than 70 years with lumbar spinal canal stenosis. Eighty-one patients older than 70 years with degenerative disorders of the lumbar spine were treated with pedicle screw fixation before 1997. They were 70 to 85 years at screw fixation (mean, 74.1 years). The postoperative follow-up period was 3 to 18 years (mean, 8.2 years). The number of fused levels by pedicle screw fixation was 1 to 7 (mean, 2.1), and bone grafting was performed in 19 patients who underwent posterolateral lumbar fusion with posterior lumbar interbody fusion and in 62 (76.5%) who underwent posterolateral lumbar fusion alone. Bone union was radiographically observed in 90.1%. The grade of independence (Independence [Bedridden] Criteria of the Daily Life of the Impaired Elderly) had been rank J (life independence) in all patients 1 year preoperatively, but deteriorated to rank A1 (capable of going out with a helper) in 51.8% of patients and rank B1 (using a wheelchair) in 19.8% immediately preoperatively. The grade of independence was rank J in 85.6% of patients 3 years postoperatively and remained rank J in 40 (87.0%) of the 46 who were alive 10 years postoperatively. Few complications associated with surgical invasion were found, and the grade of independence tended to remain at a high level for 10 years postoperatively.