Imaging Findings And Clinical Application Of Spinal And Ankle Joint Lesions In Patients With SAPHO Syndrome

Part 1 Whole-spine CT Findings in SAPHO SyndromeOBJECTIVE We evaluated the whole-spine CT findings in patients with synovitis,acne,pustulosis,hyperostosis,and osteitis(SAPHO)syndrome to improve our understanding of the disease.MATERIALS AND METHODS Whole-spine CT images obtained in 69 patients with SAPHO were reviewed.For each individual,a total of 25 vertebrae were evaluated for the distribution of affected vertebrae,CT manifestations of vertebral lesions,symmetry and location of distribution of the lesions on vertebrae,involvement pattern,and narrowing of adjacent intervertebral disc space.Paravertebral ligamentous ossifications,apophyseal joint disorders and costovertebral joint disorders were also evaluated.RESULTS All the 69 patients with SAPHO exhibited abnormalities on whole-spine CT.Sixty-four had vertebral lesions,52 had paravertebral ossifications,and 47 had both.The vertebral lesions were observed in 441 vertebrae,with a predilection for lumbosacral spine.The lesions exhibited a mixture of cortical erosion,reactive osteosclerosis ofsurrounding cancellous bone,and syndesmophyte.They may be confined to the vertebralcorner(65.1%)or be extensive,involving the endplate(34.9%).Corner lesions could start in any part of the epiphyseal ring.The lesions were asymmetrically distributed.The affected vertebrae were more consecutively involved in a "kissing" appearance(78.2%).Intervertebral disc spaces were usually normal or mildly narrowed.There were 320 foci of paravertebral ossifications observed,with a predilection for the supraspinous ligament.Paravertebral ossifications were delicate and segmental.Disorders of apophyseal joint and costovertebral joint were not observed.CONCLUSIONS Spinal involvement in SAPHO patients had a predilection for lumbosacral spine.The lesions exhibited a mixture of cortical erosion,osteosclerosis of surrounding cancellous bone and syndesmophyte.The affected vertebrae were more consecutively involved in a "kissing" appearance.Paravertebral ossifications were observed with a predilection for the supraspinous ligament.Apophyseal joint and costovertebral joint were not involved.Part 2 Whole spine and sacroiliac joint MRI findings in SAPHO syndromeOBJECTIVE We systematically evaluated the whole spine and sacroiliac joint(SIJ)MRI findings in SAPHO syndrome to improve our understanding of the disease.MATERIALS AND METHODS 38 SAPHO patients were prospectively enrolled.MRI examinations of the whole spine and SIJ were performed with standardized protocols.All the images were evaluated in a blinded manner,and discrepancies were reached in consensus after discussion.RESULTS All the 38 patients with SAPHO exhibited abnormalities on MRI.Fifteen had spinal involvement,4 had SIJ involvement,and 19 had both.(1)A total of 310 vertebrae were involved in 34 SAPHO patients.All the 34 patients had a multiple-vertebra involvement pattern(median:7,range:2-24),with a predilection on lumbosacral spine.80.3%of the affected vertebrae were continuously involved in a "kissing" appearance,while 19.7%were separately involved.Adjacent disk space was narrowed in 37.4%affected vertebrae.Thickening of anterior longitudinal ligaments was observed in 7.1%affected vertebrae.Apophyseal joint was involved in 1.3%affected vertebrae.(2)For the 310 affected vertebrae,a total of 567 lesions were observed.35.8%of the lesions were confined to vertebral corners,while 64.2%also implicated adjacent endplate.49.2%of the lesions exhibited an abnormal signal intensity(SI)of a mixture of bone marrow edema(BME)and fat deposition,while 13.9%and 36.9%demonstrated solely BME and fat deposition,respectively.Cortical bone erosion was found in 50.6%lesions,and sclerosis in 46.9%.(3)23 SAPHO patients(41 joints)were involved with SIJ disorders,and 78.3%of these patients were bilaterally involved.(4)Among the involved 41 joints,lesions distributed with a predilection on the sacrum in 58.5%.Ankylosis was observed in 14.6%affected joints.Soft tissue involvement was observed in 14.6%affected joints.CONCLUSIONS SAPHO patients with spinal involvement had a multiple-vertebra involvement pattern,with a predilection on lumbosacral spine.The affected vertebrae were more continuously involved in a "kissing" appearance.The adjacent disk spaces,posterior elements of the spine and paravertebral ligaments were mildly affected.SIJs in SAPHO patients were more bilaterally involved,with predilection on the sacrum,and with a lower prevalence of ankylosing.Part 3 The value of MRI scoring system in evaluating disease activity of SAPHO syndromeOBJECTIVE To investigate the value of MRI scoring system in evaluating disease activity of SAPHO syndrome.MATERIALS AND METHODS 30 SAPHO patients were enrolled.All the patients underwent baseline evaluation before therapy.Clinical evaluations,laboratory examinations and MRI scores were assessed.(1)Clinical evaluations:Patient’s global Visual Analogue Score(VAS)score;BASDAI=Bath ankylosing spondylitis disease activity index;BASFAI= Bath ankylosing spondylitis disease fuction index;BASMI=Bath ankylosing spondylitis disease metrology index;ASDAS-CRP= Ankylosing spondylitis disease activity score based on C-reactive protein(CRP).(2)Laboratory examinations:ESR= Erythrocyte sedimentation rate;CRP;osteocalcin and β-CTx.(3)MRI scores:All the patients were scored according to the modified Spondyloarthritis Research Consortium of Canada(SPARCC)MRI scoring system.Correlation between MRI score and clinical and laboratory evaluations was analyzed using Spearman correlation analysis.RESULTS MRI score showed a good correlation with ASDAS-CRP(r=0.601)and CRP(r=0.476).CONCLUSIONS In our study,the modified SPARCC MRI scoring system could reflect disease activity in SAPHO patients,and could be a promising tool in clinical settings.