Natural history of individuals with asymptomatic disc abnormalities in magnetic resonance imaging - Predictors of low back pain-related medical consultation and work incapacity

Study Design. Prospective study on individuals with asymptomatic lumbar dis c abnormalities detected in magnetic resonance imaging. Objectives, To determine the natural history of asymptomatic disc abnormali ties in magnetic resonance imaging and to identify predictors of future low back pain-related medical consultation and work incapacity. Summary of Background Data. The natural history of individuals with asympto matic disc herniations has not been well established, but the high rate of lumbar disc alterations recently detected in asymptomatic individuals by ma gnetic resonance imaging demands reconsideration of a pathomorphology-based explanation of low back :pain and sciatica, Methods. Forty-six asymptomatic individuals who had a high rate of disc her niations (73%) were observed for an average of 5 years (range, 54-72 months ). Four classes of variables (medical data including magnetic resonance ima ging-identified disc abnormalities, general psychological factors, physical job characteristics, and psychosocial :,aspects of work ) were assessed at baseline and follow-up. Results. Disc herniations and neural compromise did not significantly worse n at follow-up, whereas disc degeneration progressed in 17 individuals (41, 5%). Minor episodes of low back pain occurred in 19 individuals (41.3%), 6 of whom had to seek medical treatment and 5 of whom had to stop work tempor arily. The requirement for low back pain-related medical consultation was p redicted with high accuracy by listlessness, job satisfaction, and working in shifts (P < 0.001). Work incapacity was best predicted by physical job c haracteristics, job disaffection, and working in shifts (P < 0.01). Conclusion. Physical job characteristics and psychological aspects of work were more powerful than magnetic resonance imaging-identified disc abnormal ities in predicting the need for low back pain-related medical consultation and the resultant work incapacity. However, the conclusions are still prel iminary, and replication of the findings in larger and more representative study samples is needed.