Revision surgery for lumbar pseudarthrosis.

BACKGROUND CONTEXT

Revision surgery for pseudarthrosis after a lumbar spinal fusion has unpredictable functional results.

PURPOSE

The aim of this study was to determine the clinical outcomes of revision surgery to fuse the pseudarthrosis site based on the two most common diagnoses (degenerative disc disease [DDD] vs. spondylolisthesis).

STUDY DESIGN

Patients who had a revision surgery between 1995 and 2004 for lumbar pseudarthrosis after short segment lumbar spinal fusion were identified through the institution's Spine Center surgery database. A retrospective chart review of clinical, hospital, and anesthesia records was then performed.

PATIENT SAMPLE

Sixty-six patients were included in the study (28 patients with DDD and 38 patients with spondylolisthesis). Inclusion criteria were a surgical diagnosis of pseudarthrosis with a prior fusion of one or two motion segments, minimum 24 months of follow-up, and a diagnosis of either symptomatic DDD or spondylolisthesis as the primary indication for the index fusion surgery.

OUTCOME MEASURES

The Oswestry disability index (ODI) and a self-assessment questionnaire were used to evaluate clinical outcomes.

METHODS

A retrospective chart and radiographic review was performed. Statistical analysis was done using Student t test for ODI scores and chi-square test for discrete variables from the outcome questionnaires.

RESULTS

Follow-up radiographs were available for 64 patients (97%), and a fusion rate of 100% was found in both groups for the radiographs examined. The mean postoperative ODI score was 53.3 (30-84.4) for DDD patients and 37.2 (2.5-76) for the spondylolisthesis group (p<.01). Only 50% of the patients in the DDD group felt that their overall well-being had improved since the surgery. In the spondylolisthesis group, 64% of patients stated that their overall well-being had improved since their revision surgery.

CONCLUSIONS

The clinical outcomes after revision surgery for pseudarthrosis are worse in patients with DDD compared with spondylolisthesis despite successful repair of nonunion. Risks and benefits should be well discussed with the patients before deciding on surgical treatment for the management of pseudarthrosis, especially in patients with previous short-segment fusions done for DDD.