Medial meniscal ramp lesions in ACL-injured elite athletes are strongly associated with medial collateral ligament injuries and medial tibial bone bruising on MRI

Purpose Medial menisco-capsular separations (ramp lesions) are typically found in association with anterior cruciate ligament (ACL) deficiency. They are frequently missed preoperatively due to low MRI sensitivity. The purpose of this article was to describe demographic and anatomical risk factors for ramp lesions, and to identify concomitant lesions and define their characteristics to improve diagnosis of ramp lesions on MRI. Methods Patients who underwent anterior cruciate ligament (ACL) reconstruction between September 2015 and April 2019 were included in this study. The presence/absence of ramp lesions was recorded in preoperative MRIs and at surgery. Patients’ characteristics and clinical findings, concomitant injuries on MRI and the posterior tibial slope were evaluated. Results One hundred patients (80 male, 20 female) with a mean age of 22.3 ± 4.9 years met the inclusion criteria. The incidence of ramp lesions diagnosed at surgery was 16%. Ramp lesions were strongly associated with injuries to the deep MCL (dMCL, p < 0.01), the superficial medial collateral ligament (sMCL, p < 0.01), and a small medial–lateral tibial slope asymmetry (p < 0.05). There was also good correlation between ramp lesions and bone oedema in the posterior medial tibia plateau (MTP, p < 0.05) and medial femoral condyle (MFC, p < 0.05). A dMCL injury, a smaller differential medial–lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. MRI sensitivity was 62.5% and the specificity was 84.5%. Conclusion The presence on MRI of sMCL and/or dMCL lesions, bone oedema in the posterior MTP and MFC, and a smaller differential medial–lateral tibial slope than usual are highly associated with ramp lesions visible on MRI. Additionally, a dMCL injury, a flatter lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. Knowledge of the risk factors and secondary injury signs associated with ramp lesions facilitate the diagnosis of a ramp lesion preoperatively and should raise surgeons’ suspicion of this important lesion. Level of evidence Diagnostic study, Level III.

The joint involvement in adult onset Still's disease is characterised by a peculiar magnetic resonance imaging and a specific transcriptomic profile

Adult onset Still's disease (AOSD) is a rare systemic autoinflammatory disease, characterised by fever, arthritis, and skin rash, and joint involvement is one of its clinical manifestations. The aims of this work were to assess joint involvement, to describe main patterns of involvement, and associated clinical characteristics. In this work, we aimed at assessing the joint involvement in AOSD by using MRI, to describe main patterns and associated clinical characteristics. In addition, we aimed at assessing the global transcriptomic profile of synovial tissues in AOSD to elucidate possible pathogenic pathways involved. We also evaluated the global transcriptomic profile of synovial tissues to elucidate possible pathogenic pathways involved in the disease. Thus, AOSD patients, who underwent to MRI exam on joints, were assessed to describe patterns of joint involvement and associated clinical characteristics. Some synovial tissues were collected for RNA-sequencing purposes. The most common MRI finding was the presence of synovitis on 60.5%, mainly in peripheral affected joints, with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. Bone oedema and MRI-bone erosions were reported on 34.9% and 25.6% MRI exams, respectively. Patients with MRI-bone erosions showed a higher prevalence of splenomegaly, a more frequent chronic disease course, lower levels of erythrocyte sedimentation rate, and ferritin. In AOSD synovial tissues, a hyper-expression of interleukin (IL)-1, IL-6, and TNF pathways was shown together with ferritin genes. In conclusion, in AOSD patients, the most common MRI-finding was the presence of synovitis, characterised by intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. MRI-bone erosions and bone oedema were also observed. In AOSD synovial tissues, IL-1, IL-6, and TNF pathways together with ferritin genes resulted to be hyper-expressed.

POS1349 THE JOINT INVOLVEMENT IN ADULT ONSET STILL’S DISEASE IS CHARACTERISED BY A PECULIAR MAGNETIC RESONANCE IMAGING AND A SPECIFIC TRANSCRIPTOMIC PROFILE

Background:Adult onset Still’s disease (AOSD) is a rare systemic autoinflammatory disease and joint involvement is one of its clinical manifestations [1]. Arthritis, either oligoarthritis or bilateral symmetrical rheumatoid arthritis-like polyarthritis, is another common clinical feature of AOSD, with a migrating pattern at the beginning and becoming stable over the time [1].Objectives:The aims of the study were to assess joint involvement in AOSD by using magnetic resonance imaging (MRI), to describe main patterns of involvement, and associated clinical characteristics, and to evaluate the global transcriptomic profile of synovial tissues in AOSD to elucidate possible pathogenic pathways involved with.Methods:AOSD patients, who underwent to magnetic resonance imaging (MRI) exam on joints, were assessed to describe patterns of joint involvement and associated clinical characteristics. Some synovial tissues were collected for RNA-sequencing purposes.Results:In this study, 31 patients with AOSD (mean age 42.3 ± 15.2 years, 54.8% male gender), who underwent to at least one MRI exam on joints, were assessed. The most common MRI finding was the presence of synovitis on 60.5%, mainly in peripheral affected joints. MRI revealed a mild to moderate proliferative synovitis, as thickening of the synovial membrane, with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-fat saturated weighted and STIR images, suggesting the presence of a hyperplastic than of a hypertrophied synovial tissue. Bone oedema and bone erosions were reported on 34.9% and 25.6% MRI exams, respectively. In all patients but one, bone erosions were synchronous with bone oedema, overlapping completely the locations. Assessing clinical characteristics in patients with MRI-erosions, a higher prevalence of splenomegaly, a more frequent chronic disease course, lower levels of erythrocyte sedimentation rate and ferritin was observed.Assessing the synovial tissues of some AOSD patients, a moderate perivascular mononuclear infiltrate in the sub-lining stroma of hip synovial tissues was observed, whereas the lining cells were relatively unremarkable. In addition, interleukin (IL)-1β, IL-6, TNF, and heavy ferritin subunit (FeH) were found on AOSD synovial tissues.An RNA-sequencing analysis assessed the global transcriptomic profile of synovial tissues on AOSD patients and matched-controls. Assessing IL-1 pathway, we found an increased expression of il1a, il1b, il1rap, il1r1, il18r1, and Il18bp on AOSD tissues when compared with controls. In IL-6 pathway, we found an increased expression of il6 and il6st/gp130 on AOSD synovial tissues whereas an increased expression of il6r was shown on the controls. Among genes involved in TNF pathway, tnf, traf1, traf2, tnfaip3 and tnfrsf1a resulted to be more expressed in AOSD synovial tissues than in controls. Finally, fth1 and ftl were more expressed in AOSD patients than controls, when we explored the iron uptake and transport pathway.Conclusion:A peculiar MRI pattern of joint involvement in AOSD was reported; the most common finding was the presence of synovitis, characterised by intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. Bone erosions and bone oedema were also observed. This MRI pattern was associated with a hyper-activation of IL-1, IL-6, and TNF pathways together with a hyper-expression of ferritin genes on AOSD synovial tissues.References:[1]Giacomelli R, Ruscitti P, Shoenfeld Y. A comprehensive review on adult onset Still’s disease. J Autoimmun. 2018;93:24-36.Disclosure of Interests:None declared

High incidence of superficial and deep medial collateral ligament injuries in ‘isolated’ anterior cruciate ligament ruptures: a long overlooked injury

Purpose In anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically ‘isolated’ ACL ruptures. Methods Patients who underwent ACL reconstruction for complete ‘presumed isolated’ ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient’s characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests. Results Hundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus ‘ramp’ lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site (p < 0.01). Logistic regression analysis identified younger age (OR 1.2, p < 0.05), simultaneous sMCL injury (OR 6.75, p < 0.01) and the presence of bone oedema at the MFC adjacent to the dMCL attachment site (OR 5.54, p < 0.01) as predictive factors for a dMCL injury. Conclusion The incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment. Level of evidence III.

Transepiphyseal resection for osteosarcoma in patients with open physes using MRI assessment

Aims For paediatric and adolescent patients with growth potential, preservation of the physiological joint by transepiphyseal resection (TER) of the femur confers definite advantages over arthroplasty procedures. We hypothesized that the extent of the tumour and changes in its extent after neoadjuvant chemotherapy are essential factors in the selection of this procedure, and can be assessed with MRI. The oncological and functional outcomes of the procedure were reviewed to confirm its safety and efficacy. Methods We retrospectively reviewed 16 patients (seven male and nine female, mean age 12.2 years (7 to 16)) with osteosarcoma of the knee who had been treated by TER. We evaluated the MRI scans before and after neoadjuvant chemotherapy for all patients to assess the extent of the disease and the response to treatment. Results The mean follow-up period was 64.3 months (25 to 148) after surgery and no patients were lost to follow-up. On MRI evaluation, 13 tumours were near but not in contact with the physes and three tumours were partially in contact with the physes before neoadjuvant chemotherapy. Bone oedema in the epiphysis was observed in eight patients. After neoadjuvant chemotherapy, bone oedema in the epiphysis disappeared in all patients. In total, 11 tumours were not in contact and five tumours were in partial contact with the physes. The postoperative pathological margin was negative in all patients. At the last follow-up, 12 patients were continuously disease-free and three had no evidence of disease. One patient died due to the disease. Functionally, the patients with retained allograft or recycled autograft had a mean knee range of flexion of 126° (90° to 150°). The mean Musculoskeletal Tumor Society functional score was 27.6 (23 to 30). Conclusion TER is an effective limb-salvage technique for treating malignant metaphyseal bone tumours in paediatric and young osteosarcoma patients with open physes when a good response to chemotherapy and no progression of the tumour to the epiphysis have been confirmed by MRI. Cite this article: Bone Joint J 2020;102-B(6):772–778.

AB1130 LOCALIZATION OF MRI INFLAMMATORY LESIONS OF THE HAND IN SCLERODERMA AND RHEUMATOID ARTHRITIS - COMPARATIVE STUDY

Background:Inflammatory lesions of hand are frquent clinical feature in rheumatoid artritis (RA), with lower frequency in pts with systemic sclerosis (SSc), also. MR is useful method for detecting and quantification of inflammatory lesion of the hand (bone oedema, erosions, synovitis) in RA and SSc.Objectives:The aim of the study was to compare MR hand feature in SSc (experimental) and RA (control group) and to detect the localisation of the highest OMERACT RAMRISinflammatory score on the hand in pts with SSc and RAMethods:110 pts with SSc and 60 with RA were investigated (mean age 53y). All the pts underwenr clinical examination, X ray and MR on the dominant hand and wrist. Contrast enhanced low field MRI of the wrist and MCP2-5 joints was performend to all the pts. MRI inflammatory changes (bone oedema,erosions, synovitis)were assessed and scored by OMERACT RAMRIS scoring system.Results:Clinical examination confirmed synovitis in 17.1%, and 78% of patients with SSc using MR I (p <0.001). In the SSc group, erosions (by MR method) was confirmed in 52 (63.4%), by radiography in 22 pts (27.5%), which is a significantly lower percentage (p <0.001). In the control RA group, erosion was confirmed in 34 (97.1%) by MR method, and by radiography in 6 (17.1%), which is a statistically significant difference (p <0.001). Mean values of total MR score of synovitis (2.69 ± 2.29: 4.37 ± 1.31), oedema (6.58 ± 10.89: 20.57 ± 10.23) and erosion (6.84 ± 7, 43: 18.60 ± 5.01) on the wrist of the dominant hand were significantly higher in subjects with control RA than in those in the experimental SSc (p < 0.001). Mean values of total MR score of synovitis (3.15 ± 2.95: 5.26 ± 2.09), oedema (3.99 ± 9.82: 10, 51 ± 7.90) and erosion (4, 04 ± 4.76: 9.69 ± 4.27) on the MCP joints of the dominant hand were significantly higher in the control RA subjects (p <0.001).The highest OMERACR RAMRIS synovitis score was on distal radioulnar (DRU joint) of hand in SSc and also In RA pts. The highest erosion score was found on capitate bone in SSc, but in lunate bone in RA pts. The highest bone oedema score was also found on capitate bone in SSc, but in lunate bone in RA pts. According to the MCP joints, the highest synovitis score was found on the second finger in SSc and RA, highest erosion score also on the second finger in SSc, but on the third finger in RA; The highest bone oedema score was found on the third finger in SSc, and olso on the third and fifth finger in RA ptsConclusion:MR inflammatory lesions in SSc are less frequent compared to that in RA but still in significant percentage, confirming the need for early detection and aggressive treatment of both, RA and SSc patients with joint involvementReferences:[1]Avouac J, Walker UA, Hachulla E, Riemekasten G, Cuomo G, Carreira PE, et al. Joint and tendon involvement predict disease progression in systemic sclerosis: a EUSTAR prospective study. Annals of the rheumatic diseases. 2016;75(1):103–9.[2]Abdel-Magied RA, Lotfi A, AbdelGawad EA. Magnetic resonance imaging versus musculoskeletal ultrasonography in detecting inflammatory arthropathy in systemic sclerosis patients with hand arthralgia. Rheumatology international. 2013;33(8):1961–6.doi:10.1007/s00296-013-2665-8.Disclosure of Interests:None declared

P49 An unusual cause of transient migratory bone oedema: fibroblast growth factor-23 secreting a mesenchymal tumour

Background Fibroblast growth factor-23 (FGF-23) is a phosphate regulator primarily expressed by osteocytes. Excess FGF-23 leads to decreased hydroxylation of 25-hydroxyvitamin D and poor renal phosphate reabsorption. This leads to hypophosphatemia and represents a rare cause of osteomalacia, resulting in bone oedema and stress fractures. Methods A 57-year-old man with known skin psoriasis presented with a two-year history of left foot and ankle pain. On examination, he had chronic dactylitis of the big toe and extra-articular features included skin psoriasis on the scalp, elbows, knees, and nail pitting. Serum inflammatory markers were normal, and autoimmune screens for RF, anti-CCP and HLA-B27 were negative. Bilateral foot and ankle X-rays showed no bony abnormality. This was diagnosed as likely psoriatic arthritis and MRI showed talar bone oedema, felt to be related to inflammatory arthritis. Symptoms settled well on non-steroidal anti-inflammatories. However, he presented with focal distal tibial swelling and pain, two months later. There was no history of trauma, Repeat MRI2 showed proximal migration of bone oedema with stress fractures of the left posterior talus and distal tibial metaphysis. Bloods tests showed low phosphate, elevated PTH, normal adjusted calcium, raised ALP and low 25-OH vitamin D. DEXA scan confirmed osteoporosis of the hip. The patient was commenced on bisphosphonate with 25-hydroxyvitamin D and phosphate supplementation. Despite this, the patient continued to have migratory joint pain affecting the ankle, hip and sacroiliac joints. Methotrexate was started for psoriasis and whilst his skin improved, his pain remained and further MRI showed left talar and right neck of femur insufficiency fractures. Results Although taking vitamin D3 supplementation, he remained hypophosphateamic 0.5mmol/L. Myeloma screen and PET FDG were normal. However, he was noted to have an increased fractional urinary phosphate excretion indicating poor renal phosphate reabsorption. One possible cause of this is elevated FGF-23, which was confirmed with FGF-23 assay (include levels and normal range). The patient underwent PET Ga-DOTATE imaging, utilising a tracer specific for somatostatin receptors found on neuroendocrine tumours. This showed a T9 pedicle lesion and a CT-guided biopsy confirmed a mesenchymal tumour as the cause of FGF-23 secretion, resulting in TBMO and insufficiency fractures. The patient has become asymptomatic on calcitriol and phosphate supplementation. He is now being considered for radiofrequency ablation therapy. Conclusion This case illustrates the need for a thorough investigation of symptomatic, treatment-refractory hypophosphataemia. Although mild hypophosphatemia could indicate adult-onset rickets, rarer causes such as FGF-23 secreting tumours should be considered. These tumours are notoriously difficult to locate; Ga-DOTATE PET is probably superior to other imaging modalities including FDG-PET in isolating mesenchymal tumours. Disclosures K. Fisher None. S. Melath None. S. Patel None.

P41 Searching high and low for a cause of transient migratory bone oedema: fibroblast growth factor-23 secreting mesenchymal tumour

Background Fibroblast Ggrowth factor-23 (FGF-23) is a phosphate regulator primarily expressed by osteocytes. Excess FGF-23 leads to decreased hydroxylation of 25-hydroxyvitamin D and poor renal phosphate reabsorption. This leads to hypophosphataemia and represents a rare cause of osteomalacia, resulting in bone oedema and stress fractures. Methods A 57-year-old man with known skin psoriasis presented with a two-year history of left foot and ankle pain. On examination, he had chronic dactylitis of the left, big toe associated with skin psoriasis and nail pitting. Serum inflammatory markers were normal, and autoimmune screens for RF, anti-CCP and HLA-B27 were negative. Bilateral foot and ankle X-rays showed no bony abnormality. This was diagnosed as likely psoriatic arthritis and MRI showed talar bone oedema, felt to be related to the inflammatory arthritis. Symptoms settled well on non-steroidal anti-inflammatories. However, he presented two months later with focal distal tibial pain and swelling. There was no history of trauma. Repeat MRI showed proximal migration of bone oedema with stress fractures of the left posterior talus and distal tibial metaphysis. Results Blood tests showed low phosphate, elevated PTH, normal adjusted calcium, raised ALP and low 25-hydroxyvitamin D. DEXA scan confirmed osteoporosis of the hip. The patient was commenced on intravenous three-monthly pamidronate and colecalciferol (vitamin D3) supplements. Despite this, the patient continued to have migratory joint pain affecting the ankle, hip and sacroiliac joints. Methotrexate was prescribed to improve his psoriasis, but whilst his skin improved his legs remained painful. A repeat MRI showed new insufficiency fractures to the left talus and right neck of femur. Although taking colecalciferol supplementation, his serum phosphate remained low (0.5mmol/L). On further investigation, Myeloma screen and FDG PET were normal but he was noted to have an increased fractional urinary phosphate excretion indicating poor renal phosphate reabsorption. Serum FGF-23 assay was elevated at 131 mIU/L (normal &lt;100mIU/L). The patient underwent 68-Gallium DOTATATE PET imaging, utilising a tracer specific for somatostatin receptors found on neuroendocrine tumours, which showed a T9 pedicle lesion. CT-guided biopsy confirmed a mesenchymal tumour as the cause of FGF-23 secretion, resulting in transient bone marrow oedema and insufficiency fractures. The patient has become asymptomatic on calcitriol (1,25-dihydroxyvitamin D) and phosphate supplementation, and is being considered for radiofrequency ablation therapy. Conclusion This case illustrates the need for thorough investigation of symptomatic, treatment-refractory hypophosphataemia. Although mild hypophosphatemia could indicate adult onset rickets, rarer causes such as FGF-23 secreting tumours should be considered. These tumours are notoriously difficult to locate; 68-Gallium DOTATATE PET may offer superior specificity to other imaging modalities, including FDG-PET, in detecting these mesenchymal tumours. FGF-23 decreases hydroxylation of vitamin D3 and renal phosphate reabsorption, and calcitriol alongside phosphate supplementation is advisable for symptomatic management until definitive treatment. Disclosures K. Fisher None. S. Melath None. S. Patel None.

The Diagnostic Value of MRI for High Ankle Sprains with an Unstable Syndesmosis: Time to Scan Matters

Category: Ankle, Arthroscopy, Sports, Trauma Introduction/Purpose: Early clinical examination combined with MRI following a high ankle sprain allows accurate diagnosis of syndesmosis instability. However, patients often present late, and for chronic injuries clinical assessment is less reliable. The aims of the current study were to describe MRI characteristics associated with diagnosed syndesmosis instability, and to assess if MRI characteristics change as the injury becomes chronic. Methods: Patients with a high ankle sprain and proven syndesmosis instability at arthroscopy were retrospectively identified from the logbooks of two fellowship trained foot and ankle surgeons over a five-year period. Patients were excluded if they had a distal fibula fracture or absence of an MRI report by a consultant radiologist. Associations between MRI characteristics and time from injury to MRI scan, categorised as acute (< 6 weeks), intermediate (6-12 weeks) and chronic (> 12 weeks) were examined using the Pearson’s chi-squared or Fisher’s exact tests (significance set at p<0.05). Results: Of the 164 patients, 108 had an MRI scan in the acute period, 32 were classified as intermediate and 24 as chronic. A posterior syndesmosis injury was detected in 93.5% of acute patients, 87.5% of intermediate patients and 54.2% of chronic patients. In the acute group, PITFL injury was detected in 78.7% of patients, posterior malleolus bone oedema in 60.2% and posterior malleolus fracture in 15.7%. The proportion of patients with injury to the PITFL in intermediate patients was 59.4% and 29.2% in chronic patients which was significantly lower than in acute patients (p<0.001). Twenty eight patients with posterior malleolus bone oedema had an apparently normal PITFL. The proportion of patients with posterior malleolus bone oedema or fracture were not significantly different between groups. Conclusion: The most important finding of the current study is that in acute high ankle sprains with syndesmosis instability, MRI detected a posterior syndesmosis injury in 93.5% of patients. Posterior malleolus bone oedema appears to be a marker of an unstable syndesmosis injury, regardless of time from injury to the MRI scan. The ability of MRI to detect a posterior syndesmosis injury reduces significantly if delayed more than 12 weeks. If suspicious of a high ankle sprain, we advocate early MRI assessment to help determine stable versus unstable injuries, as the ability of MRI to detect posterior injuries reduces over time.