Modic Changes (MCs) Associated with Endplate Sclerosis Can Prevent Cage Subsidence in Oblique Lumbar Interbody Fusion (OLIF) Stand-Alone

Abstract

To investigate the association between Modic changes (MCs) and endplate sclerosis; and to investigate the effect of MCs and endplate sclerosis on cage subsidence in oblique lumbar interbody fusion (OLIF) stand-alone. We included 78 inpatients who underwent OLIF stand-alone from August 2015 to August 2017. All patients underwent computed tomography (CT) and magnetic resonance imaging. The presence and the types of MCs were assessed. Endplate sclerosis was evaluated from sagittally reconstructed CT images. Cage subsidence was evaluated at the 1-, 3-, 6-, and 12-month follow-up. Of 78 patients, 92 discs underwent OLIF without posterior instrumentation; 32 of 92 (34.8%) had MCs. Type I, II, and III MCs were seen in 10 (10.9%), 19 (20.7%), and 3 (3.2%) endplates, respectively. Among 32 endplates with MCs, 10 (31.3%) showed evidence of sclerosis on CT images, including 2 of 10 endplates (20%) with type I MCs, 5 of 19 (26.3%) with type II, and 3 of 3 (100%) with type III. Among 60 endplates without MCs, 5 (8.3%) showed evidence of sclerosis. Cage subsidence rate in the no-MCs group was higher than that in the MCs group (P<0.01). We found only 1 case of cage subsidence in the MCs group (n= 32), which was classified as MCs type I, whereas 6 cases of cage subsidence were observed in the no-MCs group (n= 60). Hounsfield unit ratios for sclerotic and no-sclerotic endplates were 2.2 ± 0.3 and 1.1± 0.1, respectively. No subsidence of cage was found in the sclerotic endplates group (n= 15), whereas 7 cases of cage subsidence were found in the no-sclerotic group (n= 77). MCs associated with endplate sclerosis can prevent cage subsidence in OLIF stand-alone.