Supplementary pedicle screw fixation in spinal fusion for degenerative spondylolisthesis in patients aged 65 and over: outcome after a minimum of 2 years follow-up in 82 patients.

BACKGROUND

There have been few reports assessing the outcome of laminectomy and posterolateral fusion with pedicle screw fixation for degenerative spondylolisthesis in the elderly. In a retrospective study, we assessed the clinical and radiographic outcome of this treatment in degenerative spondylolisthesis patients aged >or= 65 years.

PATIENTS AND METHODS

82 patients (61 females) aged >or= 65 years underwent laminectomy and posterolateral fusion with pedicle screw fixation for degenerative spondylolisthesis. The median age at surgery was 69 (65-79) years. The mean bone mineral density before surgery was -1.9 (-1.0 to -2.5). After an average of 3 (2-11) years follow-up, patients were classified as "satisfied" or "dissatisfied" according to self-reported outcomes and also as "solid fusion" or "no solid fusion" according to the radiographic findings.

RESULTS

At final follow-up, the average Oswestry disability index (ODI) score was lower than the preoperative score (30 vs. 56) (p = 0.03). Four-fifths of the patients stated that they were satisfied with the outcome. Almost three-quarters of the patients achieved definite fusion. Although patients with advanced age or reduced bone mineral density were not more likely to have dissatisfactory results (p = 0.8 and p = 0.6, respectively) they were more likely to have radiographic results showing "absence of solid fusion" (p = 0.005 and p < 0.001, respectively).

INTERPRETATION

We believe that supplementary pedicle screw fixation after laminectomy and posterolateral fusion will be an effective choice for the ever-increasing number of patients aged >or= 65 years who will be prone to develop degenerative spondylolisthesis.