OP0221 Is Site of Back Pain Related to Location of Inflammatory Lesions on MRI in Patients with Chronic Back Pain?
Authors: M. De Hooge, R. Van Den Berg, F. van Gaalen, M. V. Navarro Compán, M. Reijnierse, K. M. Fagerli, M. Turina, M. van Oosterhout, M. Lorenzin, T. Huizinga, D. Van Der Heijde
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> It is unclear whether location of inflammatory lesions (presence of bone marrow edema (BME)) is linked to site of pain symptoms <h3>Objectives</h3> To evaluate if localisation of back pain, as indicated by patients (pts), is related to location of BME lesions seen on MRI (in spine (MRI-spine) or sacroiliac joints (SIJ) (MRI-SI)) <h3>Methods</h3> Chronic back pain pts (≥3 months, ≤2 years, onset &lt;45 years) recruited from 5 participating centres were included in the SPondyloArthritis Caught Early (SPACE)-cohort. Pain was indicated by pts at different sites (thoracic, lumbar, buttock, total spine). Pts underwent MRI-spine and MRI-SI. On MRI-spine anterior/posterior BME and fatty lesions suggestive of spondylitis were scored when visible on ≥2 consecutive slices. For any other structural lesion (erosions or (bridging) syndesmophytes), suggestive of spondylitis, presence on ≥ 1 slice was sufficient. On MRI-SI, BME, fatty lesions, sclerosis and erosions, suggestive of spondylitis, were scored when ≥1 lesion was present on ≥2 consecutive slices or when &gt;1 lesion was present on 1 slice. Presence of ankylosis of the SIJ on ≥ 1 slice was scored. MRIs were scored independently by 3 blinded, well calibrated readers. Agreement of 2/3 readers was used. Location of MRI BME lesions was divided in spine (cervical, thoracic, lumbar) and SIJ. Association between pain site and BME location was assessed by logistic regression analysis adjusted for gender, HLA-B27 and age at onset of back pain resulting in adjusted Odds Ratios (OR) <h3>Results</h3> In 296 pts, data of the location of pain, MRI-spine (n=293) and MRI-SI (n=288) was available. Mean age at pain onset was 28.9 years, 35.1% male, 38.5% HLA-B27+, 36.5% thoracic pain, 82.4% lumbar pain, 33.8% buttock pain and 3.4% total spinal pain. Among all pts, 32.1% showed BME lesions somewhere in the spine (1.7% in cervical part, 17.6% in thoracic part, 22% in lumbar part) and 22.6% in SIJ. Any structural lesions somewhere in the spine were present in 34.1% (5.4% in cervical part, 27% in thoracic part and 19.9% in lumbar part) and fatty lesions in 25% (3% cervical, 15.2% thoracic and 11.1% lumbar) of the pts. OR of having pain and corresponding BME lesions was 2.07 (CI:1.08–3.95;p&lt;0.03) for thoracic site, 1.39 (CI:0.65–3.11, NS) for lumbar site and 0.63 (CI:0.34–1.16, NS) for buttock site. Pain was not significantly associated with structural changes on MRI-spine or MRI-SI at the same site. ORs were 1.23 (CI:0.71–2.14) for thoracic site, 0.99 (CI:0.47–2.15) for lumbar site and 1.62 (CI:0.95–2.78) for buttock site. Similar ORs were found for spinal fatty lesions. In the subgroup of axSpA pts, similar ORs were obtained, except for the relation between buttock pain and any structural lesions on MRI-SI, which resulted in a high OR of 5.10 (1.45-17.92;p=0.011) <h3>Conclusions</h3> The location of pain in the spine (thoracic, lumbar, buttock or total spine), as indicated by the patient, is only significantly related to the location of BME lesions in thoracic site in all patients with chronic back pain. In addition, in the subgroup with axSpA pts there is a significant relation between buttock pain and any structural lesions seen on MRI-SI <h3>Disclosure of Interest</h3> None Declared