Background and purpose Modic changes (MC) are bone marrow and vertebral endplate lesions seen in magnetic resonance imaging (MRI) which have been found to be associated with low back pain (LBP), but the association between MC and health-related quality of life (HRQoL) is poorly understood. The aim of this study was to assess the relationship between MC and HRQoL among patients referred to spine surgery. Methods The study population consisted of 181 patients referred to lumbar spine surgery in Northern and Eastern Finland between June 2007 and January 2011. HRQoL was assessed using RAND-36 health survey. Lumbar MC were evaluated and classified into 'No MC', 'Type I' (Type I or I/II), and 'Type II' (Type II, II/III or III). Results In total, 84 patients (46%) had MC. Of these, 37% had 'Type I' and 63% 'Type II'. Patients with MC were older, more likely females, had longer duration of LBP and a higher degree of disc degeneration than patients without MC. The total physical component or physical dimensions did not differ significantly between the groups. The total mental component of RAND-36 (P = 0.010), and dimensions of energy (P = 0.023), emotional well-being (P = 0.012) and emotional role functioning (P = 0.016) differed significantly between the groups after adjustments for age and gender. In the mental dimension scores, a statistically significant difference was found between 'No MC' and 'Type II'. Conclusions Among patients referred to spine surgery, MC were not associated with physical dimensions of HRQoL including dimension of pain. However, 'Type II' MC were associated with lower mental status of HRQoL. Implications Our study would suggest that Type II MC were associated with a worse mental status. This may affect the outcome of surgery as it is well recognized that patients with depression, for instance, have smaller improvements in HRQoL and disability. Thus the value of operative treatment for these patients should be recognized and taken into consideration in treatment. Our study shows that MC may affect outcome and thus clinicians and researchers should be cognizant of this and take this into account when comparing outcomes of surgical treatment in the future. A longitudinal study would be needed to properly address the relationship of MC with surgical outcome.
Keywords: Health-related quality of life; Intervertebral disc degeneration; Low back pain; Magnetic resonance imaging; Modic changes.