Lumbar spinal fusion surgery outcomes in a cohort of injured workers in the Victorian workers' compensation system.

Abstract

Lumbar spinal fusion (LSF) outcomes for workers' compensation patients are worse than for the general population. The objectives were to examine the long-term work capacity, opioid prescription and mental health outcomes of injured workers who have undergone LSF surgery in Victoria, Australia, and to identify demographic and pre- and post-operative characteristics associated with these outcomes. Retrospective study of 874 injured workers receiving elective LSF from 2008 to 2016 in the Victorian workers' compensation system. WorkSafe Victoria's claims data were used to infer outcomes for recovery. Association of demographics, pre-surgery and surgery variables with outcomes were modelled using multivariate multinomial logistic regression analyses. Twenty-four months after LSF surgery, 282 (32.3%) of the 874 injured workers had substantial work capacity, 388 (44.4%) were prescribed opioids, and 330 (37.8%) were receiving mental health treatment. Opioid prescription and limited work capacity before surgery were independent strong predictors of opioid prescription, reduced work capacity and mental health treatment 24 months after LSF. Pre-operative mental health treatment was associated with the use of mental health treatment at 24 months. Other predictors for poor outcomes included a greater than 12-month duration from injury to surgery, LSF re-operation and common law or impairment benefit lodgement before surgery. An association between pre-operative factors and post-operative outcomes after LSF in a Victorian workers' compensation population was identified, suggesting that pre-operative status may influence outcomes and should be considered in LSF decisions. The high opioid use indicates that opioid management before and after surgery needs urgent review.