Early Functional Outcome of Posterior Spinal Decompression for Lumbar Spinal Stenosis at a Tertiary Health Institution, South East Nigeria

Abstract

Background: Surgical treatment of lumbar spinal stenosis by posterior spinal decompression may be indicated if non-surgical management for the symptoms of low back and lower limbs radicular pains is unsuccessful and/or in patients with persisting or worsening neurological deficits. It has been reported to be an effective treatment modality in well selected patients. This procedure is however not without possible complications which can adversely affect the outcome of treatment in the affected patients. This prospective study was therefore undertaken to evaluate the early functional outcome of posterior spinal decompression for lumbar spinal stenosis at our health institution. Method: All patients with symptomatic lumbar spinal stenosis admitted for posterior spinal decompression and who met the inclusion criteria were recruited with their written informed consent. The patients’ pain severity and functional disability were assessed preoperatively with visual analogue scale (VAS) and Oswestry Disability Index (ODI). The VAS and ODI were also used to reassess the patients postoperatively, at 2 weeks, 6 weeks and 12 weeks respectively. All intraoperative and/or postoperative complications were documented and the results were analyzed. Results: The patients’ mean preoperative lower back pain and leg pain VAS score was 8.26 ± 1.46 while the mean preoperative ODI was 62.4% ±13.56. The commonest combination of spinal decompressive procedure done in the patients was laminectomy + foraminotomy in 10 (25% patients). The most common decompressed spinal level was L4/L5 (89.7%); while almost equal number of patients had either one spinal level or two-spinal level decompression (43.6% and 46.1% respectively). Postoperative pain assessment showed a mean VAS of 3.79 ± 1.15, 2.55 ± 1.27 and 2.00 ± 1.41 at 2 weeks, 6 weeks and 12 weeks respectively (p = 0.000). Functional outcome assessment with ODI was 34% ± 11.79%, 24% ± 10.75% and 18.12% ± 10.61% at 2 weeks, 6 weeks and 12 weeks respectively (p = 0.000). The commonest surgical complication seen was dura tear which occurred in nine patients (23.1%). Conclusion: There was significant reduction in low back and radicular pains with consequent functional improvement in majority of the patients who had posterior spinal decompression for lumbar spinal stenosis at our health institution. There were few complications of which dura tear was the commonest.