Disability in patients with degenerative lumbar spinal stenosis.

OBJECTIVE: To determine factors associated with disability in patients with degenerative lumbar spinal stenosis.
DESIGN: One-group cross-sectional study.
SETTING: University hospital. PARTICIPANTS: One hundred eight patients with degenerative lumbar spinal stenosis.
INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Oswestry Disability Index and 4 categories of factors, including patient demographics (age, sex, number of comorbidities, medications), symptom-related factors (intensity, location, onset duration, neurogenic claudication), body structure and function as described in the International Classification of Functioning, Disability and Health model (muscle strength, vibration sense, spine flexibility), and stenotic condition (type and number of spinal segments involved).
RESULTS: Patients with symptoms in both back and leg reported greater disability than those with symptoms only in the leg or back (P=.008). Greater disability correlated significantly with greater symptom intensity (r=.385, P<.001) and higher vibration threshold (r=.236, P=.014). While controlling the variance in patient demographics in the regression analysis, vibration sense and symptom location each added 10% of the variance in disability, and symptom intensity and strength each added 5%, with a total of 44% variance explained (P=.044).
CONCLUSIONS: Symptom intensity and location, vibration sense, and muscle strength were identified as significant factors and, together with patient demographics, accounted for 44% of the variance explained in disability. Further investigations are needed to determine if causal relationships exist between these factors and disability.