Lower effectiveness of facet joint infiltration in patients with concurrent facet joint degeneration and active endplate changes

Abstract

BACKGROUND CONTEXTFacet joint degeneration (FJD) and disc degeneration (DD) with associated endplate (EP) changes, specifically Modic 1 changes, might occur concurrently and therefore pose a challenge in the treatment of lower back pain (LBP). PURPOSEThe aim of the present study was to investigate if the presence of active EP changes (Modic 1) would alter the effect of facet joint infiltrations (FJI) for the treatment of concurrent FJD. STUDY DESIGNProspective cohort study, Level III. PATIENT SAMPLE42 patients (Male:20, Female:22) with an average of 58±14 years with FJD on conventional magnetic resonance imaging (MRI) receiving a FJI for treatment of lower back pain were included. OUTCOME MEASURESThe pain score at baseline, 15 min, 1 day, 1 week and 1 month following FJI as well as the reduction of pain were analyzed. Furthermore, active EP changes on conventional MRI and increased EP metabolic activity on PET/MRI were evaluated and compared. METHODSAll the patients underwent a (18F)-NaF PET/MRI, conventional MRI and FJI for symptomatic FJD. Active EP changes on conventional MRI and increased EP metabolic activity on PET/MR were analyzed for conformity. The pain score as well as the pain reduction at the above-mentioned time points were compared between patients with and without increased EP metabolic activity in PET/MRI. RESULTSThe LBP reduction was significantly different between patients with (n=20) and without (n=22) active EP changes at 15 minutes (1.3±2.4 vs. 2.9±2.4, p=.03) and 1 month (0.9±2.3 vs. 2.8±2.9, p<.001) following FJI. The minimal clinically important difference for LBP reduction was reached significantly more often in the absence of active EP changes (73%) compared with patients with active EP changes (35%) 1 month following FJI (p=.03). CONCLUSIONSFJI is less effective in LBP reduction of patients with FJD and concurrent active EP changes (eg Modic 1).