Outcome of lumbar fusion in Washington State workers' compensation.
METHODS
This study covered a large, population-based cohort of workers in the Washington State workers' compensation system who received lumbar fusion between August 1, 1986 and July 31, 1987 to determine work disability status, reoperation rate, and patient satisfaction.


OBJECTIVE
To use predictors of outcome of lumbar fusion to design clearer clinical guidelines for lumbar fusion in injured workers.


METHODS
Logistic regression analysis was used to determine the predictors of work disability and risk of reoperation after fusion.


RESULTS
The lumbar fusion incidence rate was 41.7/100,000 workers a year (n = 388 patients). Overall, 68% were work disabled and 23% required further lumbar spine surgery 2 years post-fusion. Five markers of severity predicted worse work disability outcome (older age at injury, longer time from injury to fusion, increased increased time on work disability before fusion, increased number of prior low back operations, and increased number of levels fused). Even after adjusting for these variables, receiving instrumentation with fusion doubled the risk of reoperation. Most patients reported that back pain (67.7%) was worse and overall quality of life (55.8%) was no better or worse than before surgery.


CONCLUSIONS
Outcome of lumbar fusion performed on injured workers was worse than reported in published case series. Prospective studies should be conducted to determine the biologic indications that might lead to improved outcomes in this disabled population.
Franklin
G M
GM
Department of Environmental Health, University of Washington School of Public Health and Community Medicine, Seattle.
Haug
J
J
Heyer
N J
NJ
McKeefrey
S P
SP
Picciano
J F
JF
D000328:Adult; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D017116:Low Back Pain / Q000453:epidemiology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D017060:Patient Satisfaction; D012086:Reoperation; D012307:Risk Factors; D013123:Spinal Fusion / Q000706:statistics & numerical data*; D013124:Spinal Injuries / Q000453:epidemiology / Q000601:surgery*; D016896:Treatment Outcome; D014861:Washington / Q000453:epidemiology; D014942:Workers' Compensation / Q000706:statistics & numerical data*