Augmented reality (AR), which entails overlay of in situ images onto the anatomy, may be a promising technique for assisting image-guided interventions. The purpose of this study was to investigate and compare the learning experience and performance of untrained operators in puncture of soft tissue lesions, when using AR ultrasound (AR US) compared with standard US (sUS). Forty-four medical students (28 women, 16 men) who had completed a basic US course, but had no experience with AR US, were asked to perform US-guided biopsies with both sUS and AR US, with a randomized selection of the initial modality. The experimental setup aimed to simulate biopsies of superficial soft tissue lesions, such as for example breast masses in clinical practice, by use of a turkey breast containing olives. Time to puncture(s) and success (yes/no) of the biopsies was documented. All participants completed questionnaires about their coordinative skills and their experience during the training. Despite having no experience with the AR technique, time to puncture did not differ significantly between AR US and sUS (median [range]: 17.0 s [6–60] and 14.5 s [5–41], p = 0.16), nor were there any gender-related differences (p = 0.22 and p = 0.50). AR US was considered by 79.5

Background: Retears after rotator cuff repair (RCR) have been associated with poor clinical results. Meaningful data regarding the role of arthroscopic revision RCR are sparse thus far. Purpose/Hypothesis: To investigate results after arthroscopic revision RCR. We hypothesized that (1) arthroscopic revision RCR would lead to improved outcomes, (2) the clinical results would be dependent on tendon integrity and (3) tear pattern, tendon involvement, and repair technique would influence clinical and structural results. Study Design: Case series; Level of evidence 4. Methods: During a 40-month period, 100 patients who underwent arthroscopic revision RCR were prospectively enrolled in this multicenter study. Outcomes were evaluated preoperatively, at 6 months (6M), and at 24 months (24M) using the Constant score (CS), the Oxford Shoulder Score (OSS), and the Subjective Shoulder Value (SSV). Tendon integrity at 2 years was analyzed using magnetic resonance imaging. A total of 13 patients (13%) were lost to follow-up, and 14 patients (14%) had a symptomatic retear before the 24M follow-up. Results: All clinical scores improved significantly during the study period (CS: preoperative, 44 ± 16; 6M, 58 ± 22; 24M, 69 ± 19 points; OSS: preoperative, 27 ± 8; 6M, 36 ± 11; 24M, 40 ± 9 points; SSV: preoperative, 43% ± 18%; 6M, 66% ± 24%; 24M, 75% ± 22%) ( P < .01). At 2 years, a retear rate of 51.8% (43/83) and a surgical revision rate of 12.6% (11/87) were observed. Mean full-thickness tear size decreased from 5.00 ± 1.61 cm2 to 3.25 ± 1.92 cm2 ( P = .041). Although the Sugaya score improved from 4.5 ± 0.9 to 3.7 ± 1.4 ( P = .043), tendon integrity did not correlate with better outcome scores. Previous open RCR, involvement of the subscapularis, chondral lesions of Outerbridge grade ≥2, and medial cuff failure were correlated with poorer SSV scores at 2 years ( P≤ .047). Patients with traumatic retears had better CS and OSS scores at 2 years ( P≤ .039). Conclusion: Although arthroscopic revision RCR improved shoulder function, retears were frequent but usually smaller. Patients with retears, however, did not necessarily have poorer shoulder function. Patient satisfaction at 2 years was lower when primary open RCR was performed, when a subscapularis tear or osteoarthritis was present, and when the rotator cuff retear was located at the musculotendinous junction. Patients with traumatic retears showed better functional improvement after revision.

Purpose Our primary aim was to describe the re-intervention and revision rates after primary reverse shoulder arthroplasty (RSA) documented in a local shoulder arthroplasty registry. We also identify the main indication for revision and re-intervention, which may be relevant for patient outcome post-RSA. Methods Since July 2006, RSAs are consecutively documented in our clinic registry and prospectively controlled with follow-ups. Any intervention after primary RSA requiring a return to the operating room for any shoulder-related indication was termed a re-intervention. Revisions were defined as surgeries involving any exchange, removal, or addition of at least one component. The study endpoints were survival rates at two, five and ten years follow-up for both definitions. Results Until July 2017, 63 from a total of 1480 primary RSAs required at least one re-intervention and 33 patients had a revision. Open reduction and internal fixation for fractures around the implant (n = 14) were the predominating indications for re-intervention. The re-intervention rate for instability was 0.5%. For re-interventions, survival rates were 97.7, 95.4 and 90.8% at two, five and ten years, respectively, and the respective rates for revisions were 98.7, 97.5 and 95.3%. Conclusion The revision rate after primary RSA for our patient registry is low. A relevant number of additional interventions were noted that did not require any component revision but may impair the final outcome post-RSA. By only reporting revision rates, the number of post-RSA re-interventions is clearly underestimated. We recommend the documentation of all events leading to any re-intervention in arthroplasty registries.

Background: The goal of this study was to evaluate whether plating and cortical bone grafting of shortened clavicular nonunions would restore clavicular length and enable bone healing. The association between the clavicular length difference (CLD) between sides and long-term functional outcome was also explored. Methods: For this retrospective 2-center study, patients who underwent plate fixation with cortical bone grafting of a clavicular nonunion were assessed after ≥2 years. The CLD and bone union were assessed using radiography and navigation ultrasound. The functional outcome was determined by the Constant score, Simple Shoulder Test score, and Subjective Shoulder Value, as well as local pain (0-10 numeric rating scale). Results: Between 2 and 13 years after surgery, 25 patients (mean age, 53 years; 13 female patients) were examined. The median CLD was 0 mm (range, –17 to 13 mm) on ultrasound measurements and 2 mm (range, –32 to 9 mm) on radiographs. At follow-up, the median Constant score, Simple Shoulder Test score, Subjective Shoulder Value, and pain level were 82 points (range, 38-95 points), 12 points (range, 3-12 points), 95% (range, 60%-100%), and 0 (range, 0-8), respectively. There was no correlation between the CLD and all functional outcome scores. Bone union was achieved in all patients. After plate removal, 4 refractures occurred, 3 of which required revision. Conclusions: Plate fixation with cortical bone grafting of clavicular nonunions is associated with restoration of clavicular length and a high rate of bone union. There is, however, a considerable risk of refracture following plate removal. There was no association between the CLD and clinical outcome.

Purpose Clinical registries are essential for evaluation of surgical outcomes. The Schulthess Shoulder Arthroplasty Registry (SAR) was established in 2006 to evaluate safety, function, quality-of-life and patient satisfaction in patients undergoing shoulder arthroplasty. Participants Adult patients undergoing anatomic or reverse shoulder joint replacement at the Schulthess Klinik, a high-volume, leading orthopaedic surgery centre in Zürich, Switzerland. Findings to date Between March 2006 and December 2019, the registry covered 98% of eligible operations. Overall, 2332 patients were enrolled with a total of 2796 operations and 11 147 person-years of follow-up. Mean age at baseline was 71 (range: 20–95), 65% were women. Most common indication was rotator cuff tears with osteoarthritis (42%) and the mean preoperative Constant Score was 31 (±15). The most frequent arthroplasty type was reverse, increasing from 61% in 2006–2010 to 86% in 2015–2019. Functional recovery peaked at 12-month postoperatively and did not show a clinically relevant deterioration during the first ten follow-up years. Since its establishment, the registry was used to address multiple pertinent clinical and methodological questions. Primary focus was on comparing different implant configurations (eg, glenosphere diameter) and surgical techniques (eg, latissimus dorsi transfer) to maximise functional recovery. Additionally, the cohort contributed to the determination of the clinical relevance and validity of radiological monitoring of cortical bone resorption and scapular notching. Finally, SAR data helped to demonstrate that returning to sports was among key patient expectations after reverse shoulder arthroplasty. Future plans As first patients are approaching the 15 years follow-up landmark, the registry will continue providing essential data on long-term functional outcomes, implant stability, revision rates and aetiologies as well as patient satisfaction and quality-of-life. In addition to research and quality-control, the cohort data will be brought back to the patients by bolstering real-time clinical decision support.

Background: The two coactivators of transcription cAMP-response element binding protein (CREB) binding protein (CBP) and p300 are close homologues. They are widely accepted as redundant proteins and unique functions have not been investigated in depth. Both proteins contain a histone acetyltransferase (HAT) activity for writing of cell type specific activating H3K27 histone acetylation marks, and a bromodomain, which functions as a reader of acetylated lysine residues on histone tails. Inhibitors targeting the bromodomains are in drug development for inflammatory and malignant diseases. Objectives: To analyze individual functions of CBP and p300 in regulating the inflammatory response of rheumatoid arthritis (RA) synovial fibroblasts (SF). Methods: SF were isolated from knee, shoulder and hand joints of RA patients undergoing joint replacement surgery. The expression of CBP and p300 was silenced by transfection of antisense LNA gapmeRs (12.5 nM). 24h after transfection, cells were stimulated with TNF-α (10 ng/ml, 24h). The levels of H3K27ac in SF were analyzed by Western blotting (n=7). Transcriptomes were determined by RNA-seq (Illumina NovaSeq 6000, n=6). Pathway enrichment analysis of RNAseq data was performed using DAVID bioinformatic resources (fold change > 1.5, FDR < 0.05, top 3000 genes included). Changes in the mRNA expression of potential target genes were confirmed by quantitative Real-time PCR (n=12-14). Results: Silencing of p300 reduced the levels of H3K27ac by 30% in unstimulated SF, and by 61.4% (p<0.05) in presence of TNF-α, whereas silencing of CBP reduced H3K27ac by 43.5% only in presence of TNF-α. In line with the changes in the H3K27ac, silencing of p300 affected the expression of 6026 and 5138 genes in unstimulated and stimulated SF, respectively. In contrast, only 285 and 1911 genes were affected by CBP silencing in unstimulated and stimulated SF, respectively. 184 genes were affected by both, CBP and p300, in unstimulated SF, with 9.2% of genes being regulated in opposite directions. 13.5% of overlapping genes affected by CBP and p300 were regulated in opposite directions in TNF-α-stimulated SF. Principal component (PC) analysis of RNAseq data separated TNF-α-stimulated from unstimulated SF (PC1) and p300 gapmeR-transfected SF (PC2) from controls and CBP gapmeR-transfected SF, which clustered together. The top pathways regulated by CBP were ‘cell cycle’ and ‘focal adhesion’ in unstimulated cells and ‘DNA replication’ and ‘cell cycle’ after stimulation with TNF-α. Top pathways regulated by p300 in presence and absence of TNF-α were ‘proteasome’, ‘spliceosome’ and ‘focal adhesion’. The expression of 16 chemokines and cytokines was changed in RNAseq data (fold change >1.5, p<0.05) by either silencing of CBP or p300. Whereas silencing of CBP reduced the expression of all of them, silencing of p300 had pro- and anti-inflammatory effects. We further confirmed expression changes in cytokine and chemokine expression by Real-time PCR. Silencing of CBP reduced the expression of IL6, CCL2 (p<0.01), CXC3L1 (p<0.05), and CXCL10. Silencing of p300 reduced the expression of CCL2 and CXC3L1 (p<0.001) but increased the expression of IL8 (p<0.001) and CXCL2 (p<0.05). Conclusion: Our results suggest that p300 is the major writer for H3K27ac marks in SF. We have identified overlapping and distinct functions for CBP and p300 in SF. CBP inhibition has anti-inflammatory effects. In contrast, p300 inhibition has pro- and anti-inflammatory functions. Disclosure of Interests: Marcel Gabathuler: None declared, Monika Krosel: None declared, Christoph Kolling: None declared, Matija Tomsic: None declared, Oliver Distler Grant/research support from: Prof. Distler received research funding from Actelion, Bayer, Boehringer Ingelheim and Mitsubishi Tanabe to investigate potential treatments of scleroderma and its complications, Consultant for: Prof. Distler has/had consultancy relationship within the last 3 years with Actelion, AnaMar, Bayer, Boehringer Ingelheim, ChemomAb, espeRare foundation, Genentech/Roche, GSK, Inventiva, Italfarmaco, iQvia, Lilly, medac, MedImmune, Mitsubishi Tanabe Pharma, Pharmacyclics, Novartis, Pfizer, Sanofi, Serodapharm and UCB in the area of potential treatments of scleroderma and its complications. In addition, he had/has consultancy relationship within the last 3 years with A. Menarini, Amgen, Abbvie, GSK, Mepha, MSD, Pfizer and UCB in the field of arthritides and related disorders, Caroline Ospelt: None declared, Kerstin Klein: None declared

Background Proteasomal degradation and autophagy are the major catabolic pathways that maintain the homeostasis of cells and are associated with cell survival. The histone acetyltransferases cAMP-response element binding protein binding protein (CBP) and p300 are close homologues and widely accepted as redundant proteins. Objectives To analyse individual functions of CBP and p300 in catabolic pathways in rheumatoid arthritis (RA) synovial fibroblasts (SF). Methods SF were isolated from knee, shoulder and hand joints of RA patients undergoing joint replacement surgery. The expression of CBP and p300 was silenced by transfection of antisense LNA gapmeRs (12,5 nM). 24h after transfection cells were stimulated with TNF-α (10 ng/ml, 24h). Transcriptomes were determined by RNA-seq (Illumina NovaSeq 6000, n=6). Pathway enrichment analysis of RNA-seq data (fold change >1.5, FDR <0.05) was performed using DAVID bioinformatic resources. Autophagy was assessed by Western blotting using LC3B conversion and p62 as autophagy markers (n=4) in presence and absence of bafilomycin A1 (100 nM, 4h), a lysosomal inhibitor. Cell death was analysed using the CytoTox-Glo cytotoxicity assay. Results The top pathway identified after silencing of p300 in SF in presence (p=1.33x10-10) and absence of TNF-α (p=1.76x10-10) was ‘proteasome’, with an enrichment of genes contributing to ‘proteasome assembly’ and ‘proteasome regulation’. The expression of several genes encoding proteasome subunits was increased after p300 silencing but unaffected by silencing of CBP. Genes contributing to the biological processes ‘autophagy’ (p<0.05) and ‘regulation of autophagy’ (p<0.05) were enriched after silencing of CBP and p300, whereas ‘autophagy assembly’ was only affected by CBP silencing. In RNA-seq data, the expression of MAP1LC3B, encoding the autophagy marker LC3B, and the autophagy substrate p62, was increased by p300 silencing but slightly decreased by CBP silencing. In line with the RNA expression, silencing of CBP reduced the conversion of LC3B and the protein expression of p62 in presence and absence of TNF-α. Results were similar in presence of bafilomycin A1, indicating a decrease in autophagosome synthesis. In contrast, the conversion of LC3B and p62 expression were increased after silencing of p300 in unstimulated SF, indicating increased autophagy. This effect was lost for LC3B after treatment with TNF-α, and LC3B conversion was even decreased in presence of bafilomycin A1. This indicates a late stage block of autophagy after silencing of p300 in TNF-α-stimulated SF. In line with this, silencing of p300 in SF (n=6, p<0.05) increased cell death only in presence of TNF-α. Viability of SF was not affected by silencing of CBP. Conclusion Here we identified p300 as a major regulator of the proteasome in SF and provide first evidence for individual functions of CBP and p300 in regulating autophagy in SF. Disclosure of Interests Monika Krosel: None declared, Marcel Gabathuler: None declared, Christoph Kolling: None declared, Matija Tomsic: None declared, Oliver Distler Grant/research support from: Prof. Distler received research funding from Actelion, Bayer, Boehringer Ingelheim and Mitsubishi Tanabe to investigate potential treatments of scleroderma and its complications, Consultant for: Prof. Distler has/had consultancy relationship within the last 3 years with Actelion, AnaMar, Bayer, Boehringer Ingelheim, ChemomAb, espeRare foundation, Genentech/Roche, GSK, Inventiva, Italfarmaco, iQvia, Lilly, medac, MedImmune, Mitsubishi Tanabe Pharma, Pharmacyclics, Novartis, Pfizer, Sanofi, Serodapharm and UCB in the area of potential treatments of scleroderma and its complications. In addition, he had/has consultancy relationship within the last 3 years with A. Menarini, Amgen, Abbvie, GSK, Mepha, MSD, Pfizer and UCB in the field of arthritides and related disorders, Caroline Ospelt: None declared, Kerstin Klein: None declared

IntroductionIncidences of scapular notching (SN) in reverse shoulder arthroplasty (RSA) range between 0% and 96%, and controversy remain as to its relevance for patient outcome. We assessed the reliability of scapular notching (SN) grading based on the Sirveaux classification system using anteroposterior radiographs.Materials and methods206 RSA procedures with 5-year postoperative anteroposterior shoulder radiographs were classified independently by seven assessors according to Sirveaux (session 1). After a review meeting, three assessors re-classified the radiographs along with quality criteria (session 2). SN grading by the majority of assessors was taken as the reference. Classification interobserver reliability was analyzed using Kappa statistics.ResultsThe incidence of SN was estimated at 53% and 37% at the first and second sessions, respectively. Interobserver reliability Kappa coefficients resulting from the first and second sessions were 0.27 and 0.43, respectively. Case selection based on radiographic quality criteria did not improve SN grading reliability in the second session.ConclusionAgreement between individual surgeons was low when grading SN in RSA according to Sirveaux using anteroposterior radiographs. Consensus among several assessors may increase reliability in research settings.

We describe the reconstruction of high-grade extensor tendon tears using a knotless suture anchor and hypothesize that this will result in improved elbow pain and function with a high healing rate. Twenty chronic lateral epicondylitis patients with magnetic resonance imaging-confirmed high-grade extensor tendon tears underwent surgery using a knotless suture anchor technique. All underwent clinical and ultrasound assessments and completed the quick Disabilities of the Arm, Shoulder, and Hand and patient-rated tennis elbow evaluation questionnaires at final follow-up. Preoperative and postoperative Mayo Elbow Performance Scores were also determined. Mean patient age at surgery was 48 years with 11 women and 7 men available at final follow-up. Diagnostic arthroscopy was performed for all patients before repair; cartilage lesions were found in 8 patients. Mayo Elbow Performance Score improved from 55 to 100 points. At final follow-up, the median grip strength was 100% (range, 52 to 114) of the nonaffected side and patient-rated scores were almost 0. We did not observe any retears. Some tennis elbow patients may present with high-grade tears that contribute to chronic symptoms. Our repair technique resulted in a satisfactory outcome for these patients and may reduce the risk of secondary posterolateral instability following complete tendon release.

Extracellular vesicles (EV) can modulate the responses of cells to toll-like receptor (TLR) ligation; conversely, TLR ligands such as double-stranded RNA (dsRNA) can enhance the release of EV and influence of the composition and functions of EV cargos. Inflamed synovial joints in rheumatoid arthritis (RA) are rich in EV and extracellular RNA; besides, RNA released from necrotic synovial fluid cells can activate the TLR3 signaling in synovial fibroblasts (SFs) from patients with RA. Since EV occur prominently in synovial joints in RA and may contribute to the pathogenesis, we questioned whether EV can interact with dsRNA, a TLR3 ligand, and modify its actions in arthritis. We have used as model the effects on RA SFs, of EV released from monocyte U937 cells and peripheral blood mononuclear cells upon stimulation with Poly(I:C), a synthetic analog of dsRNA. We show that EV released from unstimulated cells and Poly(I:C)-stimulated U937 cells [Poly(I:C) EV] differ in size but bind similar amounts of Annexin V and express comparable levels of MAC-1, the receptor for dsRNA, on the vesicular membranes. Specifically, Poly(I:C) EV contain or associate with Poly(I:C) and at least partially protect Poly(I:C) from RNAse III degradation. Poly(I:C) EV shuttle Poly(I:C) to SFs and reproduce the proinflammatory and antiviral gene responses of SFs to direct stimulation with Poly(I:C). Poly(I:C) EV, however, halt the death receptor-induced apoptosis in SFs, thereby inverting the proapoptotic nature of Poly(I:C). These prosurvival effects sharply contrast with the high toxicity of cationic liposome-delivered Poly(I:C) and may reflect the route of Poly(I:C) delivery via EV or the fine-tuning of Poly(I:C) actions by molecular cargo in EV. The demonstration that EV may safeguard extracellular dsRNA and allow dsRNA to exert antiapoptotic effects on SFs highlights the potential of EV to amplify the pathogenicity of dsRNA in arthritis beyond inflammation (by concurrently enhancing the expansion of the invasive synovial stroma).

Background Rheumatoid arthritis (RA) and other types of inflammatory arthritis follow a characteristic anatomical pattern of joint involvement. We have recently shown that local synovial stromal cells, specifically synovial fibroblasts, exhibit joint-specific transcriptomes and functions. In particular, hand SF exhibited prominent proliferative and chemotactic activities. Density of stroma and leukocyte infiltration were increased in hand synovium. Objectives To explore the role of hand/feet-specific lncRNA HOTTIP in shaping the function of hand synovial fibroblasts in arthritis. Methods We studied transcriptomes and epigenomes of hand, shoulder and knee SF from patients with RA or osteoarthritis and from knees of non-arthritic subjects using RNA-sequencing, Illumina HiSeq 2000 n=21), histone ChIP-sequencing (Illumina HiSeq 2500, n=7) and Infinium HumanMethylation450 BeadChip (n=12). qPCR was used to confirm RNA-sequencing data in a larger cohort of SF from different joints. We silenced the lncRNA HOTTIP in hand SF using LNA GapmeRs, followed by RNA-sequencing, qPCR, protein-protein interaction analysis of RNA-sequencing data (STRING), and in vitro assays for proliferation (BrdU assay) and apoptosis (Annexin V/PI staining). Results Genome-wide DNA methylation patterns and histone marks at actively transcribed DNA regions (H3K27ac) and enhancers (H3K4me1) defined joint-specific origin of SF. SF from hands and feet specifically expressed the lncRNA HOTTIP. This distal-specific HOTTIP expression coincided with the enrichment of H3K4me3 and H3K27ac and a decrease in repressive marks (H3K27me3, DNA methylation) at the HOTTIP promoter in hand SF. In contrast, the HOTTIP promoter displayed scarce activating, but abundant repressive epigenetic marks in shoulder and knee SF. Silencing of HOTTIP in hand SF altered the expression of 447 protein-coding genes (log ratio >|2|, FDR<0.05). These genes were strongly enriched in the mitotic cell cycle protein interaction network (n=48 genes, p=3.3x10–7). Several of the enriched mitotic cell cycle genes, including NCAPG, CENPO, ZWILCH and BUB1 were confirmed as downregulated by HOTTIP silencing in a larger cohort of hand SF (n=6). The basal expression of 36 out of the 48 enriched cell cycle genes correlated with the basal HOTTIP expression in hand SF (n=6, RNA-sequencing, R>|0.06|). We further measured these correlations in a larger cohort of hand SF (n=21) for a subset of the 36 genes using qPCR. Among the measured genes, TADA 3 and CDC27 were confirmed to correlate with HOTTIP expression in hand SF (R=0.5, p<0.05). Silencing of HOTTIP for 24 hour, 48 hour and 72 hour decreased the incorporation of BrdU into DNA of hand SF as measured by BrdU proliferation assay (p<0.05, n=3). Apoptosis of hand SF increased at 48 hour of HOTTIP silencing (p<0.05, n=3). Conclusions The lncRNA HOTTIP, which is specifically expressed in hand joints via epigenetic mechanisms, is a master regulator of mitotic cell cycle genes and proliferation in hand SF. Distal-specific expression of HOTTIP might imprint hand SF with enhanced proliferative potential, thereby shaping the location-specific joint pathology, e.g. prominent synovial hyperplasia and increased severity of hand arthritis in RA. Disclosure of Interest M. Frank Bertoncelj Grant/research support from: euroTEAM, BTCure, IRR, Promedica, Georg und Berta Schwyzer Winiker Grant, T. Masterson: None declared, E. Karouzakis Grant/research support from: BTCure, GSK, C. Kolling: None declared, A. Filer: None declared, C. Buckley: None declared, S. Gay Grant/research support from: euroTEAM, BTCure, GSK, IRR, O. Distler Grant/research support from: Abbvie, Actelion, Bayer, BiogenIdec, Boehringer Ingelheim, ChemomAb, espeRare foundation, Genentech/Roche, GSK, Inventiva, iQone, Lilly, medac, MedImmune, Mepha, MSD, Mitsubishi Tanabe Pharma, Novartis, Pfizer, Pharmacyclics, Sanofi, Sinoxa and UCB, Consultant for: Abbvie, Actelion, Bayer, BiogenIdec, Boehringer Ingelheim, ChemomAb, espeRare foundation, Genentech/Roche, GSK, Inventiva, iQone, Lilly, medac, MedImmune, Mepha, MSD, Mitsubishi Tanabe Pharma, Novartis, Pfizer, Pharmacyclics, Sanofi, Sinoxa and UCB, C. Ospelt Grant/research support from: euroTEAM, BTCure, CABMM, IRR, Promedica

Introduction Synovial fibroblasts (SF) from different joint localizations exhibit profound differences in their expression profiles that might predispose specific joints for certain forms of arthritis.1 Homeobox (HOX) genes were shown to play important roles in limb development and might influence the site-specific development of various diseases. Objectives To analyse the expression of distally expressed HOXD genes in SF from hands and to investigate their epigenetic regulation. Methods The expression of HOXD10, HOXD11 and HOXD13 was analysed by quantitative Real-time PCR. The histone marks H3K4me1 (enhancers), H3K4me3 (transcriptional starts of transcribed genes), H3K27me3 (inactive gene promoters) and H3K27ac (active enhancers) in SF from one RA (finger) and one osteoarthritis (OA; thumb) patient were analysed by ChIP DNA sequencing (ChIPseq). Hand SF (n=7) were treated for 24 hour with the bromodomain inhibitor I-BET151 (1 µM), targeting the bromodomain and extra-terminal domain (BET) proteins. The expression of the histone-acetyltransferases CREBBP-binding protein (CBP) and p300 was silenced by transfection of antisense LNA gapmeRs in hand SF (n=4). Results HOXD10, HOXD11 and HOXD13 transcripts were significantly increased in SF from RA and OA patients in digits II-IV and wrists compared to SF from digit I (thumb). Accordingly, ChIPseq showed an increase of H3K27ac and H3K4me3 marks in the genomic region between HOXD9 and HOXD13 in SF from a RA finger compared to SF from an OA thumb, paralleled by a loss of the repressive histone marks H3K27me3 between HOXD12 and MIR10B. Treatment of SF with I-BET151 reduced the expression of HOXD10, HOXD11 and HOXD13 by 50% (±23; p<0.001), 29% (±29; p<0.05), and 27% (±27; p<0.05) respectively. Silencing of CBP reduced the expression of HOXD10 by 47% (±10; p<0.01) and HOXD11 by 22% (±19; p=0.1) but not HOXD13. Also silencing of p300 reduced the expression of HOXD10 by 47% (±24; p=0.06) and HOXD11 by 55% (±10; p<0.01) but not HOXD13. Conclusions Distally expressed HOXD genes exhibit site-specific expression between digits II-IV and the thumb. The site-specific expression is maintained by a specific set of histone modifications and regulated by epigenetic writer (CBP, p300) and reader proteins (BET proteins). This epigenetically regulated expression of HOXD genes might influence the different occurrence of RA and OA in the small joints of the digits II-IV and the thumb. Reference . Frank-Bertoncelj, et al. Nat Commun2017. Acknowledgements Swiss National Fund (PMPDP3-171315/1), Institute of Rheumatology Research (IRR), Stiftung für wissenschaftliche Forschung, Opo-Stiftung, Hartmann Müller Stiftung Disclosure of interest K. Klein Grant/research support from: Swiss National Fund (PMPDP3-171315/1), Hartmann Müller Stiftung, M. Frank-Bertoncelj: None declared, G. Lee: None declared, C. Kolling: None declared, O. Distler Grant/research support from: Stiftung für wissenschaftliche Forschung, C. Ospelt Grant/research support from: Opo Stiftung

Background: The role of glenosphere size in reverse shoulder arthroplasty (RSA) may be important in prosthetic stability, joint kinematics, rotator cuff tension and excursion, scapular impingement, humeral lateralization, deltoid wrap, and the occurrence of "notching." This study compared short-and midterm clinical and radiographic outcomes for 2 different glenosphere sizes of a single RSA type with respect to implant positioning, glenoid size, and morphology. Methods: This retrospective analysis included 68 RSA procedures that were prospectively documented in a local register during a 5-year postoperative period. Two glenosphere diameter sizes of 36 mm (n = 33) and 44 mm (n = 35) were used. Standard radiographs were made preoperatively (ie, baseline) and at 6, 12, 24, and 60 months after surgery. Range of motion, strength, the Constant-Murley score, and the Shoulder Pain and Disability Index were also assessed at all follow-up visits. The effect of glenosphere size on measured outcomes was adjusted for baseline values, patient gender, and humeral head diameter. Results: No significant differences were found in the functional scores between treatment groups at all follow-up assessments. At the 12-month follow-up, patients with a 44-mm glenosphere had greater external rotation in adduction (mean difference, 12 degrees; P = .001) and abduction strength (mean difference, 1.4 kg; P = .026) compared with those with the smaller implant. These differences remained at 60 months. Scapular notching was observed in 38% of all patients, without any relevant difference between the groups. Conclusion: An increase in glenosphere diameter leads to a clinically moderate but significant increase in external rotation in adduction and abduction strength at midterm follow-up. (C) 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Hypothesis: We hypothesized that treatment of rotator cuff arthropathy (RCA) with reverse shoulder arthroplasty (RSA) and an additional latissimus dorsi transfer (LDT) in patients with an active external rotation deficit (ERD) would restore external rotation (ER) with concomitant deterioration in internal rotation. Methods: In our cohort study, 26 RCA patients with an active ERD (ie, positive lag sign and maximum active ER of 0 degrees) underwent RSA between September 2007 and February 2015; LDT was completed in 13 of these patients. In addition, 88 control patients without ERD who underwent only RSA were identified. Clinical outcomes of strength, range of motion, Constant-Murley score, and Shoulder Pain and Disability Index score, as well as complications, were documented 6, 12, 24, and 60 months postoperatively. We made comparative analyses using statistical mixed models. Results: The LDT procedure extended the surgical time by 26 minutes (P = .003). LDT patients had up to 22 degrees better postoperative active ER than control patients (P < .001), although this was accompanied by an internal rotation deficit (77% vs 46% of control patients could not reach the lumbosacral region, P = .010). We calculated a 23% risk of local procedure-related complications for RSA patients with an active ERD and LDT. Conclusion: Patients with RCA and an active ERD seem to benefit from an LDT, although this is accompanied by the potential loss of internal rotation. This additional procedure is associated with an extended surgical time as well as a possible increase in the risk of a complication occurring. (C) 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Targeting epigenetic reader proteins by small molecule inhibitors represents a new therapeutic concept in autoimmune diseases such as rheumatoid arthritis (RA). Although inhibitors targeting bromodomain protein 1 (BRD1) are in development, the function of BRD1 has hardly been studied. We investigated the therapeutic potential of BRD1 inhibition in joint-resident cells in RA, synovial fibroblasts (SF) and macrophages. The proliferation of SF was decreased upon BRD1 silencing, accompanied by the downregulation of genes involved in cell cycle regulation. Silencing of BRD1 in SF decreased the basal expression of MMP1 but increased TNF-α- and LPS-induced levels of MMP3, IL6 and IL8. In monocyte-derived macrophages (MDM), silencing of BRD1 decreased the LPS-induced expression of TNF-α, but did not significantly affect basal and the TNF-α- and LPS-induced expression of IL6 and IL8. Our data point to a cell type- and a stimulus-specific function of BRD1. Inhibiting BRD1 could have potential beneficial effects in RA via decreasing the proliferation of SF. Anti-inflammatory effects were limited and only observed in MDM.

Introduction Inflammatory arthritis, such as rheumatoid arthritis (RA) and spondyloarthropaties, follows a characteristic anatomical pattern of joint involvement. We suggest that the local cell types, systemic triggers and site-specific exogenous factors that activate these local cells synergistically contribute to the site-specific occurrence of arthritis. Objectives To explore the role of the local stromal cells – synovial fibroblasts (SF), in defining the joint-specific synovial biology, relevant for RA. Methods We studied transcriptomes, epigenomes and functions of hand, shoulder and knee SF from patients with RA or osteoarthritis and from knees of nonarthritic subjects with arthralgia by using RNA-sequencing (Illumina HiSeq 2000, n=21), histone ChIP-sequencing (Illumina HiSeq 2500, n=7), Infinium HumanMethylation450 BeadChip (n=12) and in vitro assays for proliferation, adhesion and chemotaxis. We silenced the long noncoding RNA HOTTIP in hand SF using LNA GapmeR, followed by RNA-sequencing (n=2), protein-protein interaction analysis (STRING) and qPCR confirmation of the HOTTIP target genes. Paraffin embedded RA synovial tissues (n=48) from different joints were scored by the Krenn synovitis score for leukocyte infiltration, synovial lining and density of synovial stroma. Results The transcriptomes, the global DNA methylation patterns and the histone marks, which mark the actively transcribed DNA regions (H3K27ac) and enhancers (H3K4me1), defined the joint-specific origin of SF. Hand SF showed prominent proliferative, chemotactic and matrix-degrading properties. Hand synovial tissues exhibited increased density of stroma and leukocyte infiltration. The homeobox (HOX) genes that regulate hand embryogenesis (HOXA13, HOTTIP) were the top differentially expressed genes with hand-specific expression in SF. This hand-specific expression pattern coincided with the specific enrichment of the activating histone marks H3K4me3 and H3K27ac and the absence of repressive H3K27me3 and DNA methylation at the HOTTIP and HOXA13 promoters in hand SF. In contrast, shoulder and knee SF displayed abundant H3K27me3 and DNA methylation, but scarce H3K4me3 and H3K27ac at the HOTTIP and HOXA13 promoters. Silencing of HOTTIP in hand SF altered the expression of 447 mRNA genes with a log ratio >|2| (FDR<0.05). The HOTTIP regulated genes were strongly enriched in the mitotic cell cycle protein interaction network (n=48 genes, p=3.29×10–7). Several of these genes were confirmed as downregulated by HOTTIP silencing in a larger cohort of hand SF (n=6, p<0.05). Besides, the basal expression of the enriched cell cycle genes, including CDC27 and TADA3, significantly correlated with the basal HOTTIP expression in hand SF (n=21). Conclusions The lncRNA HOTTIP, which is specifically expressed in hands via epigenetic mechanisms regulates the mitotic cell cycle genes. This might imprint hand SF with an enhanced proliferative potential and might promote the synovial hyperplasia in hand joints, thereby increasing the severity of hand RA. Acknowledgements IRR-IRF, Promedica, Georg und Berta Schwyzer Winiker Stiftung, CABMM. Disclosure of interest M. Frank Bertoncelj Grant/research support from: IRR-IRF, Promedica, Georg und Berta Schwyzer Winiker Stiftung, CABMM, E. Karouzakis: None declared, T. Masterson: None declared, C. Kolling: None declared, O. Distler: None declared, C. Ospelt Grant/research support from: IRR-IRF, Promedica, Georg und Berta Schwyzer Winiker Stiftung, CABMM

DNA methylation is an important epigenetic modification that is known to be altered in rheumatoid arthritis synovial fibroblasts (RASF). Here, we compared the status of promoter DNA methylation of SF from patients with very early RA with SF from patients with resolving arthritis, fully established RA and from non-arthritic patients. DNA was hybridized to Infinium Human methylation 450k and 850k arrays and differential methylated genes and pathways were identified. We could identify a significant number of CpG sites that differed between the SF of different disease stages, showing that epigenetic changes in SF occur early in RA development. Principal component analysis confirmed that the different groups of SF were separated according to their DNA methylation state. Furthermore, pathway analysis showed that important functional pathways were altered in both very early and late RASF. By focusing our analysis on CpG sites in CpG islands within promoters, we identified genes that have significant hypermethylated promoters in very early RASF. Our data show that changes in DNA methylation differ in RASF compared to other forms of arthritis and occur at a very early, clinically yet unspecific stage of disease. The identified differential methylated genes might become valuable prognostic biomarkers for RA development.