Stem cell treatment for regeneration of the rotator cuff: study protocol for a prospective single-center randomized controlled trial (Lipo-cuff).

BACKGROUND: Rotator cuff tears (RCT) are a common musculoskeletal condition, especially in the aging population. The prevalence of rotator cuff tears varies based on factors like age, occupation, and activity level. In the general population, the prevalence of rotator cuff tears is estimated to be around 20 to 25%. Rotator cuff tears (RCT) have an impact in patients' pain level, shoulder function, sleep disturbance, and quality of life. Primary tendon surgery is in mostly cases necessary. This study aimed to examine if treatment of rotator cuff lesions with implantation of micro-fragmented adipose tissue can improve patients' reported pain and function compared to conventional surgery. METHODS: The study is a prospective superiority parallel-group single-center randomized controlled trial including 30 patients between 40 and 69 years of age in Denmark. Patients will be allocated 1:1 ratio to reconstruction of the supraspinatus tendon with an injection of micro-fragmented adipose tissue into the related muscle (stem cell treatment) or the standard of care (SOC), which is conventional surgery. Patients, project assistants, physicians, and outcome adjudicators are not blinded to randomization due to practical constraints. The radiologist and the statistician performing the analysis will be blinded. The primary outcome will be the Oxford shoulder score at 12 months post-surgery. DISCUSSION: This study will assess whether adding micro-fragmented adipose tissue therapy to conventional rotator cuff tear treatment can enhance recovery, accelerate return to daily activities, and improve functional outcomes. The research will also determine if this minimally invasive procedure could be standardized for routine patient care. TRIAL REGISTRATION: ClinicalTrials.gov NCT06505135. Registered on July 10, 2024.

High-intensity resistance training improves quality of life, muscle endurance and strength in patients with myositis: a randomised controlled trial.

Myositis is associated with reduced quality of life, which is accompanied by significant impairments in muscle endurance and strength, altogether representing cardinal traits in patients with myositis. This randomised controlled trial aimed to investigate the effect of high-intensity resistance training on quality of life in patients with myositis. Thirty-two patients with established, stable myositis were randomised to 16 weeks of high-intensity resistance training (intervention group) or 16 weeks of usual care (control group). Primary outcome was quality of life assessed as the change in the physical component summary score (PCS) of the Short Form-36 health questionnaire from baseline to post-intervention. Secondary outcomes included functional capacity measures, such as functional index 3, and International Myositis Assessment and Clinical Studies Group (IMACS) disease activity and damage core set measures, including manual muscle testing 8 (MMT8). The primary outcome PCS showed an improvement in favour of high-intensity resistance training with a between-group difference of 5.33 (95% CI 0.61; 10.05) (p = 0.03). Additionally, functional index 3 showed a between-group difference indicating greater gains with high-intensity resistance training 11.49 (95% CI 3.37; 19.60) (p = 0.04), along with a between-group improvement in MMT8 1.30 (95% CI 0.09; 2.51) (p = 0.04). High-intensity resistance training for 16 weeks effectively improved quality of life in patients with myositis. Clinical measures of muscle endurance and muscle strength were also found to improve with high-intensity resistance training, while patients stayed in disease remission. Consequently, progressively adjusted high-intensity resistance training is feasible and causes no aggravation of the disease, while benefitting patients with myositis.Clinical trial registration: Clinicaltrials.gov ID: NCT04486261- https://clinicaltrials.gov/study/NCT04486261 .

A novel multitargeted self-assembling peptide-siRNA complex for simultaneous inhibition of SARS-CoV-2-host cell interaction and replication.

Effective therapeutics are necessary for managing severe COVID-19 disease despite the availability of vaccines. Small interfering RNA (siRNA) can silence viral genes and restrict SARS-CoV-2 replication. Cell-penetrating peptides is a robust method for siRNA delivery, enhancing siRNA stability and targeting specific receptors. We developed a peptide HE25 that blocks SARS-CoV-2 replication by various mechanisms, including the binding of multiple receptors involved in the virus's internalization, such as ACE2, integrins and NRP1. HE25 not only acts as a vehicle to deliver the SARS-CoV-2 RNA-dependent RNA polymerase siRNA into cells but also facilitates their internalization through endocytosis. Once inside endosomes, the siRNA is released into the cytoplasm through the Histidine-proton sponge effect and the selective cleavage of HE25 by cathepsin B. These mechanisms effectively inhibited the replication of the ancestral SARS-CoV-2 and the Omicron variant BA.5 in vitro. When HE25 was administered in vivo, either by intravenous injection or inhalation, it accumulated in lungs, veins and arteries, endothelium, or bronchial structure depending on the route. Furthermore, the siRNA/HE25 complex caused gene silencing in lung cells in vitro. The SARS-CoV-2 siRNA/HE25 complex is a promising therapeutic for COVID-19, and a similar strategy can be employed to combat future emerging viral diseases.

Effects of sporadic inclusion body myositis on skeletal muscle fibre type specific morphology and markers of regeneration and inflammation.

Sporadic inclusion body myositis (sIBM) is a subgroup of idiopathic inflammatory myopathies characterised by progressive muscle weakness and skeletal muscle inflammation. Quantitative data on the myofibre morphology in sIBM remains scarce. Further, no previous study has examined fibre type association of satellite cells (SC), myonuclei number, macrophages, capillaries, and myonuclear domain (MD) in sIBM patients. Muscle biopsies from sIBM patients (n = 18) obtained previously (NCT02317094) were included in the analysis for fibre type-specific myofibre cross-sectional area (mCSA), SCs, myonuclei and macrophages, myonuclear domain, and capillarisation. mCSA (p < 0.001), peripheral myonuclei (p < 0.001) and MD (p = 0.005) were higher in association with type 1 (slow-twitch) than type 2 (fast-twitch) fibres. Conversely, quiescent SCs (p < 0.001), centrally placed myonuclei (p = 0.03), M1 macrophages (p < 0.002), M2 macrophages (p = 0.013) and capillaries (p < 0.001) were higher at type 2 fibres compared to type 1 fibres. In contrast, proliferating (Pax7+/Ki67+) SCs (p = 0.68) were similarly associated with each fibre type. Type 2 myofibres of late-phase sIBM patients showed marked signs of muscle atrophy (i.e. reduced mCSA) accompanied by higher numbers of associated quiescent SCs, centrally placed myonuclei, macrophages and capillaries compared to type 1 fibres. In contrast, type 1 fibres were suffering from pathological enlargement with larger MDs as well as fewer nuclei and capillaries per area when compared with type 2 fibres. More research is needed to examine to which extent different therapeutic interventions including targeted exercise might alleviate these fibre type-specific characteristics and countermeasure their consequences in impaired functional performance.

Quality of life in patients with myositis is associated with functional capacity, body composition, and disease activity-Baseline data from a randomized controlled trial.

OBJECTIVE: To investigate the potential associations between functional capacity, muscle strength, body composition, and disease-related measures and quality of life in patients with myositis. METHODS: Baseline measures of functional capacity (functional index 3 (FI3), 2-minute walk test (2MWT), timed up and go (TUG) and 30-s sit-to-stand (30-STS)), muscle strength (incl. leg and handgrip strength), maximal leg extensor power, body composition (appendicular lean mass, fat percentage/mass) and disease-related measures (disease activity & damage core sets) were examined for their associations with quality of life (physical- and mental component summary scores, Short Form 36 questionnaire (SF-36)) by means of Spearman's correlation analysis. RESULTS: A total of 32 patients with myositis were included. Positive correlations between SF-36 physical component summary score (PCS) and FI3, 30-STS, TUG, 2MWT, leg extensor power, leg strength, bench press strength, and handgrip strength were observed. In contrast, fat percentage and fat mass correlated negatively with PCS. In disease-related measures, Extramuscular global assessment, health assessment questionnaire, physician global damage, and patient global damage scores were negatively associated with SF-36 PCS. No correlations to the mental component summary score of SF-36 were observed. CONCLUSION: All measures of functional capacity were positively related to the SF-36 physical component summary score, indicating higher functional capacity positively affects quality of life in patients with myositis. Health assessment questionnaire and patient global damage scores demonstrated the strongest correlations with SF-36 physical component summary scores, further supporting these patient-reported outcomes as viable monitoring tools in patients with myositis.

"Pain without loosening"-revisions of knee arthroplasties in the Danish Knee Arthroplasty Register.

INTRODUCTION: We aimed to investigate "pain without loosening" as an indication for knee arthroplasty revisions and to screen for other indications potentially hidden in this category to improve future registration and enhance data quality in the Danish Knee Arthroplasty Register. METHODS: We included 104 patients undergoing revision knee arthroplasty for the indication "pain without loosening" from 1 January 2016 to 31 December 2018 at five Danish centres. Medical records, radiographs and computed tomographies were reviewed. RESULTS: In 103 of 104 cases, we confirmed "pain without loosening" as an indication for revision. We found hidden indications in 44 cases; malposition of components (n = 19), stiffness (n = 13), progression of arthrosis (n = 6), instability (n = 3), liner dislocation (n = 1), residual cement (n = 1) and aseptic loosening (n = 1). The Kellgren-Lawrence arthrosis grades prior to primary knee arthroplasty were 1-2 (31%) and 3-4 (69%). CONCLUSIONS: The indication "pain without loosening" covered patients revised due to pain, but other hidden indications were also present. Stiffness and malposition of components were hidden indications and these are not provided as indication options in the DKR and other registers. The relatively high frequency of arthrosis grade 1-2 prior to primary knee arthroplasty is concerning and may explain the occurrence of knee pain without any other pathology present. FUNDING: The Danish Rheumatism Association, the Region of Southern Denmark, the Research Fund of Region Zeeland and Region of Southern Denmark, and the University of Southern Denmark. TRIAL REGISTRATION: Not relevant.

Effects of neuromuscular control and strengthening exercises on MRI-measured thigh tissue composition and muscle properties in people with knee osteoarthritis - an exploratory secondary analysis from a randomized controlled trial.

OBJECTIVE: To investigate the effects of adding strength training to neuromuscular control exercises on thigh tissue composition and muscle properties in people with radiographic-symptomatic knee osteoarthritis (KOA). METHODS: In this exploratory secondary analysis of a randomized controlled trial, using a complete-case approach, participants performed 12 weeks of twice-weekly neuromuscular control exercise and patient education (NEMEX, n = 34) or NEMEX plus quadriceps strength training (NEMEX+ST, n = 29). Outcomes were MRI-measured inter- and intramuscular adipose tissue (InterMAT, IntraMAT), quadriceps muscle cross-sectional area (CSA), knee-extensor strength, specific strength (strength/lean CSA) and 30 s chair-stands. Between-group effects were compared using a mixed model analysis of variance. RESULTS: At 12 weeks, responses to NEMEX+ST overlapped with NEMEX for all outcomes. Both groups reduced InterMAT (NEMEX+ST=25 %, NEMEX=21 %); between-group difference: 0.8cm2 (95 % CI: -0.1, 1.7). NEMEX+ST decreased IntraMAT (2 %) and NEMEX increased IntraMAT (4 %); between-group difference 0.1 %-points (-0.3, 0.5). Both groups increased quadriceps CSA and lean CSA (CSA minus IntraMAT), improved knee-extensor strength and specific strength, and improved chair-stand performance with a trend towards greater effects in NEMEX+ST. CONCLUSION: Adding strength training to 12 weeks of neuromuscular control exercises provided largely similar effects to neuromuscular control exercises alone in decreasing InterMAT and IntraMAT, in improving knee-extensor strength, CSA and in improving performance-based function in KOA persons, with a trend towards greater effects with additional strength training. Notably, both groups substantially reduced InterMAT and improved specific strength (an index of muscle quality). Our hypothesis-generating work warrants exploration of the roles played by InterMAT and IntraMAT in exercise effects in KOA.

Associations of dexamethasone's effect on morphine consumption after total knee arthroplasty-Subgroup analyses.

The DEXamethasone twice for pain treatment after Total Knee Arthroplasty (DEX-2-TKA) trial showed that adding one and two doses of 24 mg intravenous dexamethasone to paracetamol, ibuprofen and local infiltration analgesia, reduced morphine consumption (primary outcome) within 48 h after TKA. We aimed to explore the differences in the effect of dexamethasone on morphine consumption in different subgroups. Quantile regression adjusted for site was used to test for significant interaction between the predefined dichotomised subgroups and treatment group. The subgroups were defined based on baseline data: sex (male/female), age (≤65 years/>65 years), American Society of Anaesthesiologists (ASA)-score (ASA I + II/III), visual analogue score of preoperative pain at rest (≤30 mm/>30 mm), pain during mobilisation (≤30 mm/>30 mm), type of anaesthesia (spinal anaesthesia/general anaesthesia and spinal converted to general anaesthesia), and prior daily use of analgesics (either paracetamol and/or NSAID/neither). These analyses were supplemented with post hoc multivariate linear regression analyses. Test of interaction comparing sex in the pairwise comparison between DX2 (dexamethasone [24 mg] + dexamethasone [24 mg]) versus placebo (p = .02), showed a larger effect of dexamethasone on morphine consumption in male patients compared to females. Test of interaction comparing age in the pairwise comparison between DX1 (dexamethasone [24 mg] + placebo) versus placebo (p = .04), showed a larger effect of dexamethasone on morphine consumption in younger patients (≤65 years) compared to older. All remaining subgroup analyses showed no evidence of a difference. The supplemental multivariate analyses did not support any significant interaction for sex (p = .256) or age (p = .730) but supported a significant interaction with the type of anaesthesia (p < .001). Our results from the quantile regression analyses indicate that the male sex and younger age (≤65 years) may be associated with a larger analgesic effect of dexamethasone than the effects in other types of patients. However, this is not supported by post-hoc multivariate linear regression analyses. The two types of analyses both supported a possible interaction with the type of anaesthesia.

Long-Term Follow-up and Mortality Rate of Patients of the Randomized Freeway Stent Study.

PURPOSE: This follow-up study was designed as a reopen of the completed Freeway Stent Study and collected mortality and clinical outcome data for at least 5 years after enrollment to evaluate long-term patient safety and treatment efficacy. The primary study enrolled 204 patients with stenosis or occlusion in the superficial femoral artery and proximal popliteal artery. Patients were randomized to primary nitinol stenting followed by standard PTA or primary nitinol stenting followed by FREEWAY™ paclitaxel-eluting balloon PTA. METHODS: Previous patients were recontacted by phone or during a routine hospital visit, and medical records were reviewed. Vital and clinical status information was collected. RESULTS: No increased late mortality was observed at 5 years, with an all-cause mortality rate of 12.0% in the FREEWAY drug-eluting balloon group versus 15.0% in the non-paclitaxel PTA group. No accumulation of any cause of death was observed in either group, nor was there any correlation with the dose of paclitaxel used. Freedom from clinically driven target lesion revascularization at 5 years was significantly higher in the FREEWAY drug eluting balloon group (85.3%) compared to standard PTA group (72.7%) Log-rank p = 0.032. CONCLUSION: The safety results presented support the recent conclusions that the use of paclitaxel technology does not lead to an increase in mortality. At the same time, the efficacy results clearly demonstrate that the potential benefits of drug-eluting balloon treatment are maintained over a 5-year period.

Prolonged effects of dexamethasone following total knee arthroplasty: A pre-planned sub-study of the DEX-2-TKA trial.

OBJECTIVES: The DEX-2-TKA trial demonstrated that one and two doses of 24 mg intravenous dexamethasone reduced opioid consumption and pain after total knee arthroplasty (TKA). We aimed to investigate the prolonged effects of dexamethasone after the 48-h intervention period. DESIGN: This was a prospective, pre-planned questionnaire follow-up on postoperative days 3-7 of patients in the DEX-2-TKA trial that randomly received: DX1 (dexamethasone 24 mg + placebo), DX2 (dexamethasone 24 mg + dexamethasone 24 mg), and placebo (placebo + placebo) perioperatively and 24 h later. SETTING: A multicenter trial performed at five Danish hospitals. PARTICIPANTS: We analyzed 434 of 485 adult participants enrolled in the DEX-2-TKA trial. OUTCOME MEASURES: Primary outcome was difference between groups in average of all numerical rating scale (NRS) pain scores reported in the morning, at bedtime, and the daily average pain on postoperative days 3-7. Secondary outcomes were sleep quality and patient satisfaction. RESULTS: The median (interquartile range) pain intensity levels for postoperative days 3-7 were: DX2 3.2 (2.1-4.3); DX1 3.3 (2.3-4.1); and placebo 3.3 (2.5-4.7). Hodges-Lehmann median differences between groups were: 0 (95% confidence interval - 0.54 to 0.2), P = 0.38 between DX1 and placebo; 0.1 (-0.47 to 0.33), p = .87 between DX1 and DX2; and 0.1 (-0.6 to 0.13), p = .20 between DX2 and placebo. We found no relevant differences between groups on sleep quality on postoperative days 3-7 nor for patient satisfaction with the analgesic treatment. CONCLUSIONS: We found that neither one nor two doses of 24 mg intravenous dexamethasone demonstrated prolonged effects on overall pain or sleep quality on postoperative days 3-7 after total knee arthroplasty. We also found that dexamethasone had no effect on patient satisfaction. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT03506789 (main result trial).

Usage of guideline-adherent core treatments for knee osteoarthritis before and after consulting an orthopaedic surgeon: A prospective cohort study.

Objective: To describe 1) the proportion of patients with knee osteoarthritis (OA) undergoing guideline-adherent core treatments until six months after primary referral to an orthopaedic surgeon, 2) which specific treatment pathways these patients undertake and 3) the characteristics of patients choosing different treatment pathways. Design: This prospective cohort study consecutively invited patients referred to an orthopaedic surgeon due to knee OA at two Danish hospitals from October 2018 to December 2020. Before and six months after consulting the surgeon, patients answered a questionnaire reporting which treatments they had received for knee OA. The proportion receiving the combination of guideline-adherent treatments (i.e., exercise, education, and dietary weight management if needed) was determined. We evaluated the specific treatment usage before and until six months after the consultation and investigated characteristics of patients undertaking different pathways. Results: Out of 5251 eligible patients, 2574 (49%) had complete data and were included in analyses. 23% received guideline-adherent treatments, 10% had no treatment. Patients underwent 1143 unique treatment pathways, 62% including treatments not recommended/recommended against. Those who underwent guideline-adherent pathways had similar characteristics to those who did not but tended to be females, retired, had longer-lasting knee problems, have comorbidities, and higher education levels. Conclusions: Only one in four patients with knee OA received treatment adhering to clinical guidelines before and six months after consulting the surgeon. Patients used many different treatment pathways. There is a need for a structured effort to increase the use of guideline-adherent core treatments. Trial Identifiers: Registration: NCT03746184, Protocol: PMID: 34233992.

Tibial Component Undersizing Is Related to High Degrees of Implant Migration Following Cementless Total Knee Arthroplasty: A Study of Radiostereometric Analysis Data for 111 Patients with 2-Year Follow-up.

Radiostereometric analysis (RSA) studies have shown that the continuous migration of tibial components is predictive of aseptic loosening following total knee arthroplasty (TKA). In the present study, we investigated whether accurate sizing and placement of tibial components are related to the degree of implant migration as measured with use of RSA. Methods: A total of 111 patients who underwent TKA surgery with a cementless tibial component were followed for a period of 2 years postoperatively, during which implant migration was assessed with use of RSA. RSA was performed within 7 days postoperatively and after 3, 6, 12, and 24 months. Postoperative radiographs were evaluated for component size and placement in the tibia. The evaluations were performed by experienced knee surgeons who were blinded to the migration data and clinical outcomes. A multivariable linear regression analysis was conducted. Results: Continuous implant migration (i.e., migration occurring between 12 and 24 months postoperatively) had a negative association with tibial component size (coefficient [B], -0.2; 95% confidence interval [CI], -0.33 to -0.08). Subsidence was associated with the absence of posterior cortical bone support (B, -0.7; 95% CI, -1.09 to -0.28), the absence of lateral cortical bone support (B, 0.8; 95% CI, 0.29 to 1.37), frontal-plane varus malalignment (B, 0.6; 95% CI, 0.12 to 1.16), and component undersizing (B, -0.4; 95% CI, -0.06 to -0.68). Posterior tilt was associated only with undersizing (B, 0.6; 95% CI, 0.27 to 1.11). Conclusions: Undersized cementless tibial components are at a higher risk for poor fixation with continuous migration following TKA. Therefore, a higher risk of aseptic loosening should be expected. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Patient-reported outcomes and satisfaction after revisions of medial unicompartmental knee arthroplasties for unexplained pain vs aseptic loosening.

PURPOSE: Does patients revised for unexplained pain after mUKA present the same PROM and satisfaction scores 1-3 years after revision as patients revised for aseptic loosening?". METHODS: 104 patients undergoing revision of mUKA's for the indications unexplained pain and aseptic loosening were included in the period January 1, 2018 to December 31, 2020. from the Danish Knee Arthroplasty Register. 52 patients were revised for unexplained pain and 52 for aseptic loosening. Patient demographics did not differ between the two groups. PROMs [Oxford Knee Score (OKS), EQ-5D-5L, Forgotten Joint Score (FJS)] and questions about satisfaction with the surgery were sent to digitally secured mailboxes. Pearson's Chi-square test and Wilcoxon Rank Sum test were used to test for statistical differences between groups. RESULTS: The median OKS 1-3 years after revision was 26 (IQR 22) for unexplained pain vs 34 (IQR 12) for aseptic loosening, p = 0.033. The median EQ-5D-5L Index after revision was 0.7 (IQR 0.6) for unexplained vs 0.8 (IQR 0.1) for aseptic loosening, p = 0.014. The median FJS after revision was 48 (IQR 10) for unexplained pain vs 52 (IQR 14) for aseptic loosening, p = 0.1. The mean satisfaction with the surgery on a 0-100 scale (100 = not satisfied; 0 = very satisfied) was 55 (IQR 60) for unexplained pain vs 50 (IQR 67) for aseptic loosening, p = 0.087, and patients revised for unexplained pain were less likely to find their knee problem importantly improved (p = 0.032). CONCLUSION: Patients undergoing revision of mUKAs for unexplained pain presented poor postoperative PROM scores, and PROM scores were worse compared to those of patients revised for aseptic loosening. Patients revised for unexplained pain were less likely to find their knee problem importantly improved. This study support the evidence against revisions for unexplained pain. LEVEL OF EVIDENCE: Level III.

Short term treatment of secondary lymphedema with hyaluronidase injections reduces mouse hindlimb lymphedema.

Lymphedema is a common complication following breast cancer treatment with axillary lymphadenectomy and radiotherapy. Currently, there is no curative treatment for this disease, hence there is a need for new therapeutic suggestions. The aim of this study was to investigate the effect of hyaluronidase (HYAL) injections after inducing hindlimb lymphedema in 36 female C57BL/6 mice. HYAL injections were administered every second day for 14 days in three groups: (1) HYAL for 1 week followed by saline for 1 week, (2) HYAL for 2 weeks, and (3) saline injections for 2 weeks. Volume of the lymphedema limb was weekly assessed with micro-computed tomography (µ-CT) scans for a total course of 6 weeks. Lymph vessel morphometry was assessed in the end of the study after staining cross-sections of the hindlimb for anti-LYVE-1 blindly. Lymphatic function was assessed by lymphoscintigraphy to assess lymphatic clearance. There was a significant reduction of the volume of lymphedema in mice treated with HYAL-7 compared with mice treated with HYAL-14 (p < 0.05) and saline (p < 0.05). No differences were detected in lymph vessel morphometry and the lymphoscintigraphy between groups. Short-term treatment with HYAL-7 might be a potential therapeutic suggestion for secondary lymphedema induced in mouse hindlimbs. In the future, clinical studies are needed to investigate the potential of HYAL treatment in human beings.

Sporadic late onset nemaline myopathy with concurrent dermatological symptoms responding to immunosuppressive treatment.

BACKGROUND: Sporadic late onset nemaline myopathy is a rare, progressive muscle disease, presenting in adulthood, mainly affecting proximal limb and bulbar muscles. Muscle biopsies show characteristic nemaline rods. The putative mechanism is considered immune-related. Other manifestations aside from neuromuscular symptoms have not been described previously. CASE PRESENTATION: We present a case with atypical sporadic late onset nemaline myopathy (SLONM) of a non-HIV, non-MGUS subtype, where skin manifestations preceded neuromuscular symptoms, and a residual thymus with the histology of thymic follicular hyperplasia was detected during the diagnostic workup. Thorough dermatological investigations could not explain the skin presentations. Muscle biopsy revealed variation in fiber diameter, ragged-red and COX-negative fibers associated with discrete fibrosis. Electron microscopy detected atrophic muscle fibres with disorganization of the myofibrils, nemaline rods and abnormal mitochondria. Single-fiber EMG suggested signs of a neuromuscular transmission defect, EMG showed signs of myopathy. Analyses of antibodies associated with myasthenia gravis were negative. The patient showed improvement after intravenous immunoglobulin treatment regarding both the skin and the muscle symptoms. CONCLUSIONS: Our case highlights the heterogeneity of SLONM with its varied spectrum of presentation. A unique combination of dermatological symptoms and SLONM could be seen with skin lesions as primary presenting symptoms. An association can be considered between the different manifestations, presumably based on immune etiology, where immunosuppressive therapy has been beneficial.

Myopathy as a cause of Long COVID fatigue: Evidence from quantitative and single fiber EMG and muscle histopathology.

OBJECTIVE: To describe neurophysiological abnormalities in Long COVID and correlate quantitative electromyography (qEMG) and single fiber EMG (sfEMG) results to clinical scores and histopathology. METHODS: 84 patients with non-improving musculoskeletal Long COVID symptoms were examined with qEMG and sfEMG. Muscle biopsies were taken in a subgroup. RESULTS: Mean motor unit potential (MUP) duration was decreased in ≥ 1 muscles in 52 % of the patients. Mean jitter was increased in 17 % of the patients in tibialis anterior and 25 % in extensor digitorum communis. Increased jitter was seen with or without myopathic qEMG. Low quality of life score correlated with higher jitter values but not with qEMG measures. In addition to our previously published mitochondrial changes, inflammation, and capillary injury, we show now in muscle biopsies damage of terminal nerves and motor endplate with abundant basal lamina material. At the endplate, axons were present but no vesicle containing terminals. The post-synaptic cleft in areas appeared atrophic with short clefts and coarse crests. CONCLUSIONS: Myopathic changes are common in Long COVID. sfEMG abnormality is less common but may correlate with clinical scores. sfEMG changes may be due to motor endplate pathology. SIGNIFICANCE: These findings may indicate a muscle pathophysiology behind fatigue in Long COVID.

Ryanodine receptor 1 related myasthenia like myopathy responsive to pyridostigmine.

Disease causing variants in the Ryanodine receptor 1 (RYR1) gene are a common cause for congenital myopathy and for malignant hyperthermia susceptibility. We report a 17 year old boy with congenital muscle weakness progressing to a myasthenia like myopathy with muscle weakness, fatigability, ptosis, and ophthalmoplegia. Muscle biopsy showed predominance and atrophy of type 1 fibers. Whole-exome trio sequencing revealed three variants in the RYR1-gene in the patient: c.6721C > T,p.(Arg2241*) and c.2122G > A,p.(Asp708Asn) in cis position, and the c.325C > T,p.(Arg109Trp) variant in trans. Treatment with pyridostigmine improved symptoms. This case supports that a myasthenia like phenotype is part of the phenotypic spectrum of RYR1 related disorders, and that treatment with pyridostigmine can be beneficial for patients with this phenotype.

Patient-Reported Outcomes and Satisfaction 1 to 3 Years After Revisions of Total Knee Arthroplasties for Unexplained Pain Versus Aseptic Loosening.

BACKGROUND: It is unknown if patients are relieved of pain after knee arthroplasty revision for unexplained pain. The aim of this cross-sectional case-control study was to compare patient-reported outcome measures (PROMs) and satisfaction 1 to 3 years after revision of total knee arthroplasties (TKAs) for the indications of unexplained pain versus aseptic loosening. METHODS: We included 384 patients undergoing TKA revision for the indications of unexplained pain and aseptic loosening from January 1, 2018 to December 31, 2020 from the Danish Knee Arthroplasty Register. A total of 81 patients were revised for unexplained pain and 303 for aseptic loosening. Questionnaires including PROMs (Oxford Knee Score, EQ-5D-5L, and Forgotten Joint Score) and satisfaction with the surgery on a 0-100 scale (100 = not satisfied; 0 = very satisfied) were sent to digitally secured mailboxes. Time from revision to data collection was a median 3.1 years (range, 1.4-4.4 years). RESULTS: Median Oxford Knee Score was 25 (interquartile range [IQR] 15) versus 31 (IQR 18) 1-3 years after revisions for unexplained pain versus aseptic loosening, P = .009. Median EQ-5D-5L was 0.6 (IQR 0.4) versus 0.8 (IQR 0.3) for unexplained pain versus aseptic loosening, P = .009. Median Forgotten Joint Score was 50 (IQR 7) versus 50 (IQR 16) for unexplained pain versus aseptic loosening, P = .905. Satisfaction was 75 (IQR 38) for unexplained pain and 50 (IQR 73) for aseptic loosening, P < .001. CONCLUSION: Patients undergoing TKA revision for the indication of unexplained pain had worse results on PROMs than those revised for aseptic loosening. Likewise, patients revised for unexplained pain were less satisfied compared to patients revised for aseptic loosening. This information is valuable to both surgeons and patients when candidates for revision surgery are selected, to obtain the best possible outcomes.

Impact of Nordic Arthroplasty Register Association (NARA) collaboration on demographics, methods and revision rates in knee arthroplasty: a register-based study from NARA 2000-2017.

BACKGROUND AND PURPOSE: We have previously observed differences in treatment and outcome of knee arthroplasties in the Nordic countries. To evaluate the impact of Nordic collaboration in the last 15 years we aimed to compare patient demographics, methods, and revision rates in primary knee arthroplasties among the 4 Nordic countries. PATIENTS AND METHODS: We included 535,051 primary knee arthroplasties reported 2000-2017 from the Nordic Arthroplasty Register Association (NARA) database. Kaplan-Meier analysis (KM) and restricted mean survival time (RMST) analysis were used to evaluate the cumulative revision rate (CRR) and RMST estimates with 95% confidence intervals (CI) and to compare countries in relation to risk of revision for any reason. RESULTS: After 2010, the increase in incidence of knee arthroplasty plateaued in Sweden and Denmark but continued to increase in Finland and Norway. In 2017 the incidence was highest in Finland with 226 per 105 person-years, while it was less than 150 per 105 in the 3 other Nordic countries. In total knee arthroplasties performed for osteoarthritis (OA), overall CRR at 15 years for revision due to any reason was higher in Denmark (CRR 9.6%, 95% CI 9.2-10), Norway (CRR 9.1%, CI 8.7-9.5), and Finland (CRR 7.0%, CI 6.8-7.3) compared with Sweden (CRR 6.6%, CI 6.4-6.8). There were differences among the countries in use of implant brand and type, fixation, patellar component, and use of unicompartmental knee arthroplasty. INTERPRETATION: We evinced a slowing growth of incidence of knee arthroplasties in the Nordic countries after 2010 with Finland having the highest incidence. We also noted substantial differences among the 4 Nordic countries, with Sweden having a lower risk of revision than the other countries. No impact of NARA could be demonstrated and CRR did not improve over time.