Obesity and litigation predict workers' compensation costs associated with interbody cage lumbar fusion

Background context: Results of lumbar fusion surgery have been mixed and procedures are costly. Interbody cage lumbar fusion (ICLF) has been advanced to improve arthrodesis and clinical outcomes; however, little attention has been given to ICLF costs or potential predictors of these expenses. Purpose: To depict medical and compensation costs associated with ICLF in a Utah cohort of patients receiving workers' compensation as well as to investigate predictors of costs. Study design/setting: A retrospective-cohort research design was used involving completion of presurgical and postsurgical medical record reviews and accrual of medical and compensation costs. Presurgical variables included in a regression model were presurgical spinal pathophysiology rating, obesity, and litigation status. Patient sample: Forty-three consecutive patients who were compensated by the Workers' Compensation Fund of Utah and underwent ICLF. Outcome measures: Total accrued compensation and medical costs. Methods: A retrospective review of presurgical variables and total accrued compensation and medical costs was conducted. Results: Multiple regression analysis indicated that nonpathophysiological factors predicted compensation costs (lawyer involvement [β=0.40]; obesity [β=0.34]). Specifically, compensation for those with versus without lawyers was $41,657 versus $24,837, and for those who were obese versus nonobese was $46,152 versus $28,168. Arthrodesis was correlated with medical costs (r=-0.47, p=.002), with incurred costs for patients achieving solid fusion versus pseudarthrosis equaling $38,881 versus $71,655, respectively. Conclusions: Considerable costs were associated with ICLF, particularly for those who were obese, involved in litigation, or failed to achieve solid fusion. With regard to compensation costs, the findings support the importance of assessing nonpathophysiological factors in spinal fusion patients.