USE OF THE EXERCISE TREADMILL TO MEASURE BASE-LINE FUNCTIONAL STATUS AND SURGICAL OUTCOME IN PATIENTS WITH SEVERE LUMBAR SPINAL STENOSIS

Study Design. A prospective study of exercise tolerance on the treadmi ll before and after decompressive laminectomy in patients with severe lumbar Spinal stenosis. Objectives: To determine whether treadmill tes ting provides useful information about baseline functional status and surgical outcome. Summary of Background Data, Historically, criteria f or selecting patients for surgery and assessing postoperative outcome have been variable. Functional testing has not been used in a systemat ic fashion. Methods: Fifty patients living with spinal stenosis underw ent decompressive laminectomy. Pre-operatively and 3 months postoperat ively, functional capacity was assessed on an exercise treadmill. Time to first symptoms and total ambulation time were recorded. The examin ation was stopped at the onset of severe symptoms or after 15 minutes. Results. !nl the preoperative trial, mean time to first symptoms of s tandard deviation) was 1.82 minutes (median, p.58), and mean ambulatio n time was 6.91 minutes (median, 5.22). In the postoperative trial, me an time to first symptoms increased to 11.93 minutes (median) and mean total ambulation time increased to 13.26 minutes (median) 15). There was significant improvement after surgery in both time to first sympto ms(P< 0.001) and total ambulation rime (P <0.001). Conclusion. Exercis e stress testing on a a treadmill is safe easily administered, and qua ntifiable means of assessing baseline functional status and surgical o utcome in patients neurogenic claudication due to lumbar spinal stenos is. Treadmill testing provides objective evidence that surgery is bene ficial in most cases and is helpful in guiding subsequent management o f patients with residual symptoms.