|Titel på arbejdet
|Long-term outcomes in degenerative spine patients - with focus on Modic changes and discectomy surgery
|Peter Muhareb Udby
|Afdeling / Sted
|Ortopædkirurgisk afdeling SUH og Rygsektionen Middelfart Sygehus - en del af Sygehus Lillebælt
|Abstract / Summary
Back pain is a common cause of global disability. Modic changes (MCs) are commonly found on Magnetic Resonance Imaging (MRI) in adults with back pain. These characteristic changes have been classified into three different types and are visualized on MRI in the endplates and bone marrow adjacent to a degenerated intervertebral disc. MCs have been associated with low back pain (LBP) and disability in previous studies. Additionally, MCs have been associated with a less successful outcome in LBP patients treated surgically. However, previous studies have been limited by small, heterogeneous cohorts with short follow-up. In addition, limited information is available on the long-term prognosis of patients with LBP and MCs not receiving surgical treatment.
The purpose of the thesis was to evaluate the possible association between MCs, disc degeneration (DD) and facet-joint degeneration (FJD), and patient-reported outcomes (PRO) at long-term follow-up. Moreover, we aimed to evaluate if preoperative MCs are associated with outcome after discectomy.
The first two studies included patients with LBP recruited from a previous randomized controlled trial. Of the original 207 patients in the randomized cohort, 204 had a lumbar MRI performed in 2004-2005. Study I focused on the possible association between the baseline MCs on MRI and disability 13-years later. Patients were stratified based on the presence (+MC group) or absence (-MC group) of MCs. There were 82 patients in the +MC group and 122 in the -MC group. 170 patients (83%) were available for 13-year follow-up. At baseline, demographics, PRO (including Roland-Morris Disability Questionnaire (RMDQ)), and pain scores were comparable with no statistically significant difference between the two groups. At 13-year follow-up the +MC group had statistically significantly better RMDQ-scores and less sick-leave in the past year compared to the –MC group. In study II, the same cohort was analyzed in terms of MRI parameters including DD (defined by Pfirrmann grade >3), FJD (defined by Fujiwara grade >2), and MCs. Neither DD, FJD nor MCs at baseline were found to be associated with increased 13-year disability or higher pain scores. Both weekly physical activity at leisure and MCs at baseline were associated with less long-term disability.
Study III was a registry-based cohort study on patients with lumbar disc herniation who underwent primary discectomy. We included 620 patients, all with two-year postoperative follow-up. We analyzed preoperative MRIs in all included patients and found MCs present in 290 patients (47%). Preoperative demographics and PRO were comparable between the +MC and -MC groups. An overall statistically and clinically significant improvement in PRO after discectomy was found in both groups. We found no difference in PRO between the +/-MC groups.
We conclude that MCs in LBP patients do not appear to be associated with long-term disability. Baseline degenerative MRI findings including DD and FJD are likewise not associated with long-term disability. Furthermore, MCs do not appear to be associated with outcome after primary discectomy.