The Cellular and Molecular Signature of ALS in Muscle

Amyotrophic lateral sclerosis is a disease affecting upper and lower motor neurons. Although motor neuron death is the core event of ALS pathology, it is increasingly recognized that other tissues and cell types are affected in the disease, making potentially major contributions to the occurrence and progression of pathology. We review here the known cellular and molecular characteristics of muscle tissue affected by ALS. Evidence of toxicity in skeletal muscle tissue is considered, including metabolic dysfunctions, impaired proteostasis, and deficits in muscle regeneration and RNA metabolism. The role of muscle as a secretory organ, and effects on the skeletal muscle secretome are also covered, including the increase in secretion of toxic factors or decrease in essential factors that have consequences for neuronal function and survival.

Agreement Between Isokinetic Dynamometer and Hand-held Isometric Dynamometer as Measures to Detect Lower Limb Asymmetry in Muscle Torque After Anterior Cruciate Ligament Reconstruction

Background

Two commonly used instruments to assess muscle strength after anterior cruciate ligament reconstruction are the isokinetic dynamometer, which measures isokinetic torque and the hand-held dynamometer, which measures isometric torque. Isokinetic dynamometers are considered superior to other instruments but may not be commonly used in clinical settings. Hand-held dynamometers are small, portable, and more clinically applicable devices.

Purpose

The purpose of this study was to assess agreement between a hand-held dynamometer and an isokinetic dynamometer, used to assess lower limb symmetry in knee muscle torque one year after anterior cruciate ligament (ACL) reconstruction.

Study design

Cross-sectional measurement study.

Methods

Seventy-two participants who had undergone ACL reconstruction (35 men, 37 women; age= 25.8 ± 5.4 years) were included. Isokinetic muscle torque in knee flexion and extension was measured with an isokinetic dynamometer. Isometric flexion and extension knee muscle torque was measured with a hand-held dynamometer. Bland & Altman plots and Cohen's Kappa coefficient were used to assess agreement between measurements obtained from the instruments.

Result

Bland & Altman plots showed wide limits of agreement between the instruments for both flexion and extension limb symmetry index. Cohen´s Kappa coefficient revealed a poor to slight agreement between the extension limb symmetry index values (0.136) and a fair agreement for flexion limb symmetry index values (0.236). Cross-tabulations showed that the hand-held dynamometer detected a significantly larger number of participants with abnormal flexion torque limb symmetry index compared to the isokinetic dynamometer.

Conclusion

The wide limits of agreements and Cohen's Kappa coefficients values revealed insufficient agreement between the measurements taken with the two instruments, indicating that the instruments should not be used interchangeably. The hand-held dynamometer was more sensitive in detecting abnormal limb symmetry index in flexion torque, which promotes the option of use of hand-held dynamometers to detect differences between the injured and uninjured leg after ACL reconstruction.

Level of evidence

3b.

Overview of non-coding RNAs in breast cancers

Breast cancer in women is the second most common cancer and the fifth leading cause of cancer death worldwide. Although earlier diagnosis and detection of breast cancer has resulted in lower mortality rates, further advances in prevention, detection, and treatment are needed to improve outcomes and survival for women with breast cancer as well as to offer a personalized therapeutic approach. It is now well-established that non-coding RNAs (ncRNAs) represent 98% of the transcriptome but in-depth knowledge about their involvement in the regulation of gene expression is lacking. A growing body of research indicates that ncRNAs are essential for tumorigenesis by regulating the expression of tumour-related genes. In this review, we focus on their implication in breast cancer genesis but also report the latest knowledge of their theragnostic and therapeutic role. We highlight the need for accurate quantification of circulating ncRNAs which is determinant to develop reliable biomarkers. Further studies are mandatory to finally enter the era of personalized medicine for women with breast cancer.

Decellularized Bovine Pericardial Patch Loaded With Mesenchymal Stromal Cells Enhance the Mechanical Strength and Biological Healing of Large-to-Massive Rotator Cuff Tear in a Rat Model

PURPOSE

The purpose of this study was to determine whether the addition of decellularized bovine pericardial patch loaded with mesenchymal stromal cells enhanced bone-to-tendon healing and improved the biomechanical strength of large-to-massive rotator cuff tears in a small animal model.

METHODS

Adipose-derived mesenchymal stromal cells (MSCs) from rat inguinal fat were isolated, cultured, and loaded onto decellularized bovine pericardium patches. To simulate large-to-massive tears, rats were managed with free cage activity for 6 weeks after tear creation. A total of 18 rats were randomly allocated to repair-only (control), repair with pericardial patch augmentation (patch), or repair with MSC loaded pericardial patch augmentation (patch-MSC). Each group had 6 rats (one shoulder of each rat was used for histological evaluation and another for biomechanical evaluation). MSCs seeded on the pericardial patches were traced on four shoulders from 2 other rats at 4 weeks after surgery. Histological evaluation for bone-to-tendon healing and biomechanical testing was carried out at 8 weeks after repair.

RESULTS

MSCs tagged with a green fluorescent protein were observed in the repair site 4 weeks after the repair. One shoulder each in the control and patch groups showed complete discontinuity between the bone and tendon. One shoulder in the control group showed attenuation with only a tenuous connection. Fibrocartilage and tidemark formation at the bone-to-tendon interface (P = .002) and collagen fiber density (P = .040) and orientation (P = .003) were better in the patch-MSC group than in the control or patch group. Load-to-failure in the patch-MSC and patch groups was higher than that in the control group (P = .001 and .009, respectively).

CONCLUSION

Decellularized bovine pericardial patches loaded with adipose-derived and cultured mesenchymal stromal cells enhanced healing in terms of both histology and mechanical strength at 8 weeks following rotator cuff repair in a rat model.

CLINICAL RELEVANCE

Large-to-massive rotator tears need a strategy to prevent retear and enhance healing. The addition of decellularized bovine pericardial patch loaded with MSCs can enhance bone-to-tendon healing and improve biomechanical healing of large-to-massive rotator cuff tears following repair.

Strain-Dependent Diffusivity of Small and Large Molecules in Meniscus

Due to lack of full vascularization, the meniscus relies on diffusion through the extracellular matrix to deliver small (e.g., nutrients) and large (e.g., proteins) to resident cells. Under normal physiological conditions, the meniscus undergoes up to 20% compressive strains. While previous studies characterized solute diffusivity in the uncompressed meniscus, to date, little is known about the diffusive transport under physiological strain levels. This information is crucial to fully understand the pathophysiology of the meniscus. The objective of this study was to investigate strain-dependent diffusive properties of the meniscus fibrocartilage. Tissue samples were harvested from the central portion of porcine medial menisci and tested via fluorescence recovery after photobleaching to measure diffusivity of fluorescein (332 Da) and 40 K Da dextran (D40K) under 0%, 10%, and 20% compressive strain. Specifically, average diffusion coefficient and anisotropic ratio, defined as the ratio of the diffusion coefficient in the direction of the tissue collagen fibers to that orthogonal, were determined. For all the experimental conditions investigated, fluorescein diffusivity was statistically faster than that of D40K. Also, for both molecules, diffusion coefficients significantly decreased, up to ∼45%, as the strain increased. In contrast, the anisotropic ratios of both molecules were similar and not affected by the strain applied to the tissue. This suggests that compressive strains used in this study did not alter the diffusive pathways in the meniscus. Our findings provide new knowledge on the transport properties of the meniscus fibrocartilage that can be leveraged to further understand tissue pathophysiology and approaches to tissue restoration.

MicroRNA signatures in genetic frontotemporal dementia and amyotrophic lateral sclerosis

OBJECTIVE

MicroRNAs are promising biomarkers of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), but discrepant results between studies have so far hampered their use in clinical trials. We aim to assess all previously identified circulating microRNA signatures as potential biomarkers of genetic FTD and/or ALS, using homogeneous, independent validation cohorts of C9orf72 and GRN mutation carriers.

METHODS

104 individuals carrying a C9orf72 or a GRN mutation, along with 31 controls, were recruited through the French research network on FTD/ALS. All subjects underwent blood sampling, from which circulating microRNAs were extracted. We measured differences in the expression levels of 65 microRNAs, selected from 15 published studies about FTD or ALS, between 31 controls, 17 C9orf72 presymptomatic subjects, and 29 C9orf72 patients. We also assessed differences in the expression levels of 30 microRNAs, selected from five studies about FTD, between 31 controls, 30 GRN presymptomatic subjects, and 28 GRN patients.

RESULTS

More than half (35/65) of the selected microRNAs were differentially expressed in the C9orf72 cohort, while only a small proportion (5/30) of microRNAs were differentially expressed in the GRN cohort. In multivariate analyses, only individuals in the C9orf72 cohort could be adequately classified (ROC AUC up to 0.98 for controls versus presymptomatic subjects, 0.94 for controls versus patients, and 0.77 for presymptomatic subjects versus patients) with some of the signatures.

INTERPRETATION

Our results suggest that previously identified microRNAs using sporadic or mixed cohorts of FTD and ALS patients could potentially serve as biomarkers of C9orf72-associated disease, but not GRN-associated disease.

Comparison of Face-to-Face vs Digital Delivery of an Osteoarthritis Treatment Program for Hip or Knee Osteoarthritis

Importance

Digital care platforms have been introduced, but there is limited evidence for their efficacy compared with traditional face-to-face treatment modalities.

Objective

To compare mean pain reduction among individuals with osteoarthritis (OA) of the knee or hip who underwent face-to-face vs digital first-line intervention.

Design, Setting, and Participants

This registry-based cohort study included all persons with knee or hip osteoarthritis who participated in structured first-line treatment for osteoarthritis in a primary care setting in Sweden. Inclusion criteria were as follows: the treatment was delivered face-to-face or digitally between April 1, 2018, and December 31, 2019; patients provided 3-month follow-up data for pain; and patients had program adherence of at least 80%. Data analysis was conducted in March 2021.

Exposures

Participants completed a 3-month intervention, including education and exercise for hip or knee osteoarthritis, with program adherence of 80% or higher, delivered face-to-face or by a digital application.

Main Outcomes and Measures

Difference in change in joint pain (11-point numeric rating scale, with 0 indicating no pain and 10, the worst possible pain) between baseline and 3-month follow-up between the 2 intervention modalities. A minimal clinically important difference in pain change between groups was predefined as 1 point. Secondary outcomes were walking difficulties, health-related quality of life, willingness to undergo joint surgery, and fear avoidance behavior.

Results

A total of 6946 participants (mean [SD] age, 67 [9] years; 4952 [71%] women; 4424 [64%] knee OA; 2504 [36%] hip OA) were included, with 4237 (61%) receiving face-to-face treatment and 2709 (39%) receiving digital treatment. Both the face-to-face (mean change, -1.10 [95% CI -1.17 to -1.02] points) and digital interventions (mean change, -1.87 [95% CI, -1.94 to -1.79] points) resulted in a clinically important pain reduction at 3 months. Participants in the digitally delivered intervention experienced a larger estimated improvement at 3 months (adjusted mean difference, -0.93 [95% CI, -1.04 to -0.81] points). Results of secondary outcomes were broadly consistent with main outcome.

Conclusions and Relevance

This Swedish national registry-based cohort study showed that people with knee or hip OA participating in first-line intervention experienced clinically relevant improvements in pain, whether delivered face-to-face or digitally. The increased benefit of digital delivery compared with face-to-face delivery was of uncertain clinical importance.

Adversarial Evolving Neural Network for Longitudinal Knee Osteoarthritis Prediction

Knee osteoarthritis (KOA) as a disabling joint disease has doubled in prevalence since the mid-20th century. Early diagnosis for the longitudinal KOA grades has been increasingly important for effective monitoring and intervention. Although recent studies have achieved promising performance for baseline KOA grading, longitudinal KOA grading has been seldom studied and the KOA domain knowledge has not been well explored yet. In this paper, a novel deep learning architecture, namely adversarial evolving neural network (A-ENN), is proposed for longitudinal grading of KOA severity. As the disease progresses from mild to severe level, ENN involves the progression patterns for accurately characterizing the disease by comparing an input image it to the template images of different KL grades using convolution and deconvolution computations. In addition, an adversarial training scheme with a discriminator is developed to obtain the evolution traces. Thus, the evolution traces as fine-grained domain knowledge are further fused with the general convolutional image representations for longitudinal grading. Note that ENN can be applied to other learning tasks together with existing deep architectures, in which the responses characterize progressive representations. Comprehensive experiments on the Osteoarthritis Initiative (OAI) dataset were conducted to evaluate the proposed method. An overall accuracy was achieved as 62.7%, with the baseline, 12-month, 24-month, 36-month, and 48-month accuracy as 64.6%, 63.9%, 63.2%, 61.8% and 60.2%, respectively.

3D Cell Culture as Tools to Characterize Rheumatoid Arthritis Signaling and Development of New Treatments

Rheumatoid arthritis (RA) is one of the most common autoimmune disorders affecting 0.5-1% of the population worldwide. As a disease of multifactorial etiology, its constant study has made it possible to unravel the pathophysiological processes that cause the illness. However, efficient and validated disease models are necessary to continue the search for new disease-modulating drugs. Technologies, such as 3D cell culture and organ-on-a-chip, have contributed to accelerating the prospecting of new therapeutic molecules and even helping to elucidate hitherto unknown aspects of the pathogenesis of multiple diseases. These technologies, where medicine and biotechnology converge, can be applied to understand RA. This review discusses the critical elements of RA pathophysiology and current treatment strategies. Next, we discuss 3D cell culture and apply these methodologies for rheumatological diseases and selected models for RA. Finally, we summarize the application of 3D cell culture for RA treatment.

Composing On-Program Triggers and On-Demand Stimuli into Biosensor Drug Carriers in Drug Delivery Systems for Programmable Arthritis Therapy

Medication in arthritis therapies is complex because the inflammatory progression of rheumatoid arthritis (RA) and osteoarthritis (OA) is intertwined and influenced by one another. To address this problem, drug delivery systems (DDS) are composed of four independent exogenous triggers and four dependent endogenous stimuli that are controlled on program and induced on demand, respectively. However, the relationships between the mechanisms of endogenous stimuli and exogenous triggers with pathological alterations remain unclear, which results in a major obstacle in terms of clinical translation. Thus, the rationale for designing a guidance system for these mechanisms via their key irritant biosensors is in high demand. Many approaches have been applied, although successful clinical translations are still rare. Through this review, the status quo in historical development is highlighted in order to discuss the unsolved clinical difficulties such as infiltration, efficacy, drug clearance, and target localisation. Herein, we summarise and discuss the rational compositions of exogenous triggers and endogenous stimuli for programmable therapy. This advanced active pharmaceutical ingredient (API) implanted dose allows for several releases by remote controls for endogenous stimuli during lesion infections. This solves the multiple implantation and local toxic accumulation problems by using these flexible desired releases at the specified sites for arthritis therapies.

Long-Term Blockade of Nociceptive Nav1.7 Channels Is Analgesic in Rat Models of Knee Arthritis

The voltage gated sodium channels (Nav) 1.7, 1.8, and 1.9 are primarily located on nociceptors where they are involved in signalling neuropathic pain. This study examined the effect of Nav1.7 blockade on joint pain using either the small molecule inhibitor PF05089771 or an antibody directed towards the intracellular domain of the ion channel. Male Wistar rats were assigned to one of three experimental groups consisting of either intra-articular injection of 3 mg sodium monoiodoacetate (MIA-joint degeneration group), intra-articular injection of 100 μg lysophosphatidic acid (LPA-joint neuropathy group), or transection of the medial meniscus (MMT-posttraumatic osteoarthritis group). G-ratio calculations were performed to determine potential demyelination and immunohistochemistry was used to measure Nav1.7 expression on joint afferent cell bodies. Pain behaviour was evaluated over 3 h by von Frey hair algesiometry and hindlimb weight bearing before and after local administration of PF05089771 (0.1 mg/50 µL). Chronic pain behaviour was assessed over 28 days following peripheral treatment with a Nav1.7 antibody (Ab) in conjunction with the transmembrane carrier peptide Pep1. Demyelination and increased Nav1.7 channel expression were observed in MIA and LPA rats, but not with MMT. Acute secondary allodynia was diminished by PF05089771 while a single injection of Nav1.7 Ab-Pep1 reduced pain up to 28 days. This analgesia only occurred in MIA and LPA animals. Hindlimb incapacitance was not affected by any treatment. These data indicate that joint pain associated with neural demyelination can be alleviated somewhat by Nav1.7 channel blockade. Biologics that inactivate Nav1.7 channels have the potential to reduce arthritis pain over a protracted period of time.

Muscle-to-Brain Signaling Via Myokines and Myometabolites

Skeletal muscle health and function are important determinants of systemic metabolic homeostasis and organism-wide responses, including disease outcome. While it is well known that exercise protects the central nervous system (CNS) from aging and disease, only recently this has been found to depend on the endocrine capacity of skeletal muscle. Here, we review muscle-secreted growth factors and cytokines (myokines), metabolites (myometabolites), and other unconventional signals (e.g. bioactive lipid species, enzymes, and exosomes) that mediate muscle-brain and muscle-retina communication and neuroprotection in response to exercise and associated processes, such as the muscle unfolded protein response and metabolic stress. In addition to impacting proteostasis, neurogenesis, and cognitive functions, muscle-brain signaling influences complex brain-dependent behaviors, such as depression, sleeping patterns, and biosynthesis of neurotransmitters. Moreover, myokine signaling adapts feeding behavior to meet the energy demands of skeletal muscle. Contrary to protective myokines induced by exercise and associated signaling pathways, inactivity and muscle wasting may derange myokine expression and secretion and in turn compromise CNS function. We propose that tailoring muscle-to-CNS signaling by modulating myokines and myometabolites may combat age-related neurodegeneration and brain diseases that are influenced by systemic signals.

Adjunctive platelet-rich plasma and hyaluronic acid injection after arthroscopic debridement in Kellgren-Lawrence grade 3 and 4 knee osteoarthritis

BACKGROUND

Osteoarthritis (OA) is the most common cause of pain and disability, predominantly affecting the knee. The current management of knee OA falls short of completely stopping disease progression, particularly in Kellgren-Lawrence (KL) grade 3 and 4 knee OA. As such, joint replacement is often recommended, although only 15%-33% of candidates accept it. Alternative therapeutic options are still needed to prevent the progression of joint damage and delay the need for knee arthroplasty.

AIM

To investigate the effect of adjunctive platelet rich plasma (PRP) and hyaluronic acid (HA) after arthroscopic debridement in KL grade 3 and 4 knee OA.

METHODS

This retrospective cohort study used the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and WOMAC sub-scores (pain, stiffness, and function) to assess 21 patients, grouped according to medical record data of treatment received: Arthroscopic debridement (n = 7); arthroscopic debridement with PRP (n = 7); or arthroscopic debridement with HA (n = 7). WOMAC scores and sub-scores at baseline and at 3 mo and 5 mo posttreatment were recorded. The three-group data were statistically analyzed using the tests of paired t, one-way analysis of variance, and post hoc least significant difference.

RESULTS

All three treatment groups showed significant improvements in WOMAC score and sub-scores from before treatment to 3 mo and 5 mo after treatment. However, the arthroscopic debridement with PRP treatment group, in particular, showed a significantly lower WOMAC pain score than the group who received arthroscopic debridement alone at 5 mo after the procedure (P = 0.03).

CONCLUSION

Compared to arthroscopic debridement alone, adjunctive PRP after arthroscopic debridement significantly lessened the patients’ pain symptom.

Elucidating the Ability of CGRP to Modulate Microvascular Events in Mouse Skin

Oedema formation and polymorphonuclear leukocyte (neutrophil) accumulation are involved in both acute and chronic inflammation. Calcitonin gene-related peptide (CGRP) is a sensory neuropeptide that is released from stimulated sensory nerves. CGRP is a potent vasodilator neuropeptide, especially when administered to the cutaneous microvasculature, with a long duration of action. Here, we have investigated the ability of vasodilator amounts of CGRP to modulate oedema formation and neutrophil accumulation induced in the cutaneous microvasculature of the mouse. To learn more about the mechanism of action of endogenous CGRP, we have investigated the response to the inflammatory stimulants tumour necrosis factor alpha (TNFα) and carrageenan in three different murine models: a model where sensory nerves were depleted by resiniferatoxin (RTX); a pharmacological method to investigate the effect of a selective CGRP receptor antagonist; and a genetic approach using wildtype (WT) and αCGRP knockout (KO) mice. Our results show that exogenous CGRP potentiates oedema formation induced by substance P (SP) and TNFα. This is further supported by our findings from sensory nerve-depleted mice (in the absence of all neuropeptides), which indicated that sensory nerves are involved in mediating the oedema formation and neutrophil accumulation induced by TNFα, and also carrageenan in cutaneous microvasculature. Furthermore, endogenous CGRP was shown to contribute to this inflammatory response as carrageenan-induced oedema formation is attenuated in WT mice treated with the CGRP receptor antagonist, and in αCGRPKO mice. It is therefore concluded that CGRP can contribute to inflammation by promoting oedema formation in skin, but this response is dependent on the pro-inflammatory stimulus and circumstance.

Non-Oncological Radiotherapy: A Review of Modern Approaches

Despite being usually delivered in oncological patients, radiotherapy can be used as a successful treatment for several non-malignant disorders. Even though this use of radiotherapy has been scarcely investigated since the 1950s, more recent interest has actually shed the light on this approach. Thus, the aim of this narrative review is to analyze the applications of non-oncological radiotherapy in different disorders. Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used. This review contains a narrative report and a critical discussion of non-oncological radiotherapy approaches. In conclusion, non-oncological radiotherapy is a safe and efficacious approach to treat several disorders that needs to be further investigated and used in clinical practice.

Prediction Models to Estimate the Future Risk of Osteoarthritis in the General Population: A Systematic Review

OBJECTIVE

To evaluate the performance and applicability of multivariable prediction models for osteoarthritis (OA).

METHODS

This was a systematic review and narrative synthesis using 3 databases (EMBASE, PubMed, and Web of Science) from inception to December 2021. We included general population longitudinal studies reporting derivation, comparison, or validation of multivariable models to predict individual risk of OA incidence, defined by recognized clinical or imaging criteria. We excluded studies reporting prevalent OA and joint arthroplasty outcome. Paired reviewers independently performed article selection, data extraction, and risk-of-bias assessment. Model performance, calibration, and retained predictors were summarized.

RESULTS

A total of 26 studies were included, reporting 31 final multivariable prediction models for incident knee (23), hip (4), hand (3) and any-site OA (1), with a median of 121.5 (range 27-12,803) outcome events, a median prediction horizon of 8 years (range 2-41), and a median of 6 predictors (range 3-24). Age, body mass index, previous injury, and occupational exposures were among the most commonly included predictors. Model discrimination after validation was generally acceptable to excellent (area under the curve = 0.70-0.85). Either internal or external validation processes were used in most models, although the risk of bias was often judged to be high with limited applicability to mass application in diverse populations.

CONCLUSION

Despite growing interest in multivariable prediction models for incident OA, focus remains predominantly on the knee, with reliance on data from a small pool of appropriate cohort data sets, and concerns over general population applicability.

Utility of Plasma Protein Biomarkers and Mid-infrared Spectroscopy for Diagnosing Fracture-related Infections: A Pilot Study

OBJECTIVES

To compare a large panel of plasma protein inflammatory biomarkers and mid-infrared (MIR) spectral patterns in patients with confirmed fracture-related infections (FRIs) with those in controls without infection.

DESIGN

Prospective case-control study.

SETTING

Academic, Level 1 trauma center.

PATIENTS

Thirteen patients meeting confirmatory FRI criteria were matched to 13 controls based on age, time after surgery, and fracture region.

INTERVENTION

Plasma levels of 49 proteins were measured using enzyme-linked immunosorbent assay techniques. Fourier transform infrared spectroscopy of dried films was used to obtain MIR spectra of plasma samples.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements included plasma protein levels and MIR spectra of samples.

RESULTS

Multivariate analysis-based predictive model developed using enzyme-linked immunosorbent assay-based biomarkers had sensitivity, specificity, and accuracy of 69.2% ± 0.0%, 99.9% ± 1.0%, and 84.5% ± 0.6%, respectively, with platelet-derived growth factor-AB/BB, C-reactive protein, and MIG selected as the minimum number of variables explaining group differences ( P < 0.05). Sensitivity, specificity, and accuracy of the predictive model based on MIR spectra were 69.9% ± 6.2%, 71.9% ± 5.9%, and 70.9% ± 4.8%, respectively, with 6 wavenumbers as explanatory variables ( P < 0.05).

CONCLUSIONS

This pilot study demonstrates the feasibility of using a select panel of plasma proteins and Fourier transform infrared spectroscopy to diagnose FRIs. Preliminary data suggest that the measurement of these select proteins and MIR spectra may be potential clinical tools to detect FRIs. Further investigation of these biomarkers in a larger cohort of patients is warranted.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Multi-stage treatment for malunion and avascular necrosis of the femoral head following reverse oblique pertrochanteric fracture: A case report and literature review

Femoral reverse oblique intertrochanteric fractures are successfully treated using intramedullary devices. Poor fracture reduction and the use of the inaproppriate implant can lead to implant failure and subsequent malunion or non-union. We present the case of a 21-year-old polytrauma female who, among other injuries, sustained a reverse oblique intertrochanteric fracture that was primarily operated on with the dynamic hip screw. After implant failure the patient developed malunion with bone defect and avascular necrosis of the femoral head. Successful salvage of the bone stock in the inter- and subtrochanteric region was achieved using the two-stage induced membrane technique. The uncemented total hip arthroplasty was performed to address the osteonecrosis of the femoral head.

Effectiveness of an Unsupervised Online Yoga Program on Pain and Function in People With Knee Osteoarthritis : A Randomized Clinical Trial

BACKGROUND

Yoga is a mind-body exercise typically done in groups in person, but this delivery method can be inconvenient, inaccessible, and costly. Effective online programs may increase access to exercise for knee osteoarthritis.

OBJECTIVE

To evaluate the effectiveness of an unsupervised 12-week online yoga program.

DESIGN

Two-group superiority randomized trial. (Australian New Zealand Clinical Trials Registry: ACTRN12620000012976).

SETTING

Community.

PARTICIPANTS

212 adults with symptomatic knee osteoarthritis.

INTERVENTION

Both groups received online osteoarthritis information (control). The yoga group also received access to an unsupervised online yoga program delivered via prerecorded videos over 12 weeks (1 video per week, with each session to be performed 3 times per week), with optional continuation thereafter.

MEASUREMENTS

Primary outcomes were changes in knee pain during walking (0 to 10 on a numerical rating scale) and physical function (0 to 68 on the Western Ontario and McMaster Universities Osteoarthritis Index) at 12 weeks (primary time point) and 24 weeks, analyzed using mixed-effects linear regression models. Secondary outcomes were self-reported overall knee pain, stiffness, depression, anxiety, stress, global change, quality of life, self-efficacy, fear of movement, and balance confidence. Adverse events were also collected.

RESULTS

A total of 195 (92%) and 189 (89%) participants provided 12- and 24-week primary outcomes, respectively. Compared with control at 12 weeks, yoga improved function (between-group mean difference in change, -4.0 [95% CI, -6.8 to -1.3]) but not knee pain during walking (between-group mean difference in change, -0.6 [CI, -1.2 to 0.1]), with more yoga participants than control participants achieving the minimal clinically important difference (MCID) for both outcomes. At 12 weeks, knee stiffness, quality of life, and arthritis self-efficacy improved more with yoga than the control intervention. Benefits were not maintained at 24 weeks. Adverse events were minor.

LIMITATION

Participants were unblinded.

CONCLUSION

Compared with online education, an unsupervised online yoga program improved physical function but not knee pain at 12 weeks in people with knee osteoarthritis, although the improvement did not reach the MCID and was not sustained at 24 weeks.

PRIMARY FUNDING SOURCE

National Health and Medical Research Council and Centres of Research Excellence.

Comparative effect of two educational videos on self-efficacy and kinesiophobia in people with knee osteoarthritis: an online randomised controlled trial

OBJECTIVE

To compare change in self-efficacy for managing knee osteoarthritis (OA) pain and kinesiophobia after watching an educational video based on an empowerment and participatory discourse with a video based on a disease and impairment discourse.

DESIGN

Two-arm randomised controlled trial with participants aged ≥45 years with knee pain (n = 589). Participants completed both baseline and follow-up outcomes and watched one randomly-allocated video (12-minute duration) during one 30-45-minute session within a single online survey. The experimental video presented evidence-based knee OA information using design and language that aimed to empower people and focus on activity participation to manage OA, while the control video presented similar information but with a disease and impairment focus. Primary outcome measures were Arthritis Self-Efficacy Scale pain subscale (range 0-10) and Brief Fear of Movement Scale for OA (range 6-24). Secondary outcomes were expectations about prognosis and physical activity benefits, perceived importance and motivation to be physically active, knee OA knowledge, hopefulness for the future, level of concern and perceived need for surgery.

RESULTS

Compared to control (n = 293), the experimental group (n = 296) showed improved self-efficacy for managing OA pain (mean difference 0.4 [95%CI 0.2, 0.6] units) and reduced kinesiophobia (1.6 [1.1, 2.0] units). The experimental group also demonstrated greater improvements in all secondary outcomes apart from hopefulness, which was high in both groups.

CONCLUSION

An educational video based on an empowerment and participatory discourse improved pain self-efficacy and reduced kinesiophobia in people with knee OA more than a video based on a disease and impairment discourse.

CLINICALTRIALS

gov registration NCT05156216, Universal trial number U1111-1269-6143.

An Explainable Machine Learning Pipeline for Stroke Prediction on Imbalanced Data

Stroke is an acute neurological dysfunction attributed to a focal injury of the central nervous system due to reduced blood flow to the brain. Nowadays, stroke is a global threat associated with premature death and huge economic consequences. Hence, there is an urgency to model the effect of several risk factors on stroke occurrence, and artificial intelligence (AI) seems to be the appropriate tool. In the present study, we aimed to (i) develop reliable machine learning (ML) prediction models for stroke disease; (ii) cope with a typical severe class imbalance problem, which is posed due to the stroke patients' class being significantly smaller than the healthy class; and (iii) interpret the model output for understanding the decision-making mechanism. The effectiveness of the proposed ML approach was investigated in a comparative analysis with six well-known classifiers with respect to metrics that are related to both generalization capability and prediction accuracy. The best overall false-negative rate was achieved by the Multi-Layer Perceptron (MLP) classifier (18.60%). Shapley Additive Explanations (SHAP) were employed to investigate the impact of the risk factors on the prediction output. The proposed AI method could lead to the creation of advanced and effective risk stratification strategies for each stroke patient, which would allow for timely diagnosis and the right treatments.

Prognostic molecular biomarkers in chordomas: A systematic review and identification of clinically usable biomarker panels

Introduction and objective

Despite the improvements in management and treatment of chordomas over time, the risk of disease recurrence remains high. Consequently, there is a push to develop effective systemic therapeutics for newly diagnosed and recurrent disease. In order to tailor treatment for individual chordoma patients and develop effective surveillance strategies, suitable clinical biomarkers need to be identified. The objective of this study was to systematically review all prognostic biomarkers for chordomas reported to date in order to classify them according to localization, study design and statistical analysis.

Methods

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically reviewed published studies reporting biomarkers that correlated with clinical outcomes. We included time-to-event studies that evaluated biomarkers in skull base or spine chordomas. To be included in our review, the study must have analyzed the outcomes with univariate and/or multivariate methods (log-rank test or a Cox-regression model).

Results

We included 68 studies, of which only 5 were prospective studies. Overall, 103 biomarkers were analyzed in 3183 patients. According to FDA classification, 85 were molecular biomarkers (82.5%) mainly located in nucleus and cytoplasm (48% and 27%, respectively). Thirty-four studies analyzed biomarkers with Cox-regression model. Within these studies, 32 biomarkers (31%) and 22 biomarkers (21%) were independent prognostic factors for PFS and OS, respectively.

Conclusion

Our analysis identified a list of 13 biomarkers correlating with tumor control rates and survival. The future point will be gathering all these results to guide the clinical validation for a chordoma biomarker panel. Our identified biomarkers have strengths and weaknesses according to FDA's guidelines, some are affordable, have a low-invasive collection method and can be easily measured in any health care setting (RDW and D-dimer), but others molecular biomarkers need specialized assay techniques (microRNAs, PD-1 pathway markers, CDKs and somatic chromosome deletions were more chordoma-specific). A focused list of biomarkers that correlate with local recurrence, metastatic spread and survival might be a cornerstone to determine the need of adjuvant therapies.

miR-140-5p and miR-140-3p: Key Actors in Aging-Related Diseases?

microRNAs (miRNAs) are small single strand non-coding RNAs and powerful gene expression regulators. They mainly bind to the 3′UTR sequence of targeted mRNA, leading to their degradation or translation inhibition. miR-140 gene encodes the pre-miR-140 that generates the two mature miRNAs miR-140-5p and miR-140-3p. miR-140-5p/-3p have been associated with the development and progression of cancers, but also non-neoplastic diseases. In aging-related diseases, miR-140-5p and miR-140-3p expressions are modulated. The seric levels of these two miRNAs are used as circulating biomarkers and may represent predictive tools. They are also considered key actors in the pathophysiology of aging-related diseases. miR-140-5p/-3p repress targets regulating cell proliferation, apoptosis, senescence, and inflammation. This work focuses on the roles of miR-140-3p and miR-140-5p in aging-related diseases, details their regulation (i.e., by long non-coding RNA), and reviews the molecular targets of theses miRNAs involved in aging pathophysiology.

Lipid Metabolism in Cartilage Development, Degeneration, and Regeneration

Lipids affect cartilage growth, injury, and regeneration in diverse ways. Diet and metabolism have become increasingly important as the prevalence of obesity has risen. Proper lipid supplementation in the diet contributes to the preservation of cartilage function, whereas excessive lipid buildup is detrimental to cartilage. Lipid metabolic pathways can generate proinflammatory substances that are crucial to the development and management of osteoarthritis (OA). Lipid metabolism is a complicated metabolic process involving several regulatory systems, and lipid metabolites influence different features of cartilage. In this review, we examine the current knowledge about cartilage growth, degeneration, and regeneration processes, as well as the most recent research on the significance of lipids and their metabolism in cartilage, including the extracellular matrix and chondrocytes. An in-depth examination of the involvement of lipid metabolism in cartilage metabolism will provide insight into cartilage metabolism and lead to the development of new treatment techniques for metabolic cartilage damage.

PHLPP Inhibitor NSC74429 Is Neuroprotective in Rodent Models of Cardiac Arrest and Traumatic Brain Injury

Pleckstrin homology domain and leucine rich repeat protein phosphatase (PHLPP) knockout mice have improved outcomes after a stroke, traumatic brain injury (TBI), and decreased maladaptive vascular remodeling following vascular injury. Thus, small-molecule PHLPP inhibitors have the potential to improve neurological outcomes in a variety of conditions. There is a paucity of data on the efficacy of the known experimental PHLPP inhibitors, and not all may be suited for targeting acute brain injury. Here, we assessed several PHLPP inhibitors not previously explored for neuroprotection (NSC13378, NSC25247, and NSC74429) that had favorable predicted chemistries for targeting the central nervous system (CNS). Neuronal culture studies in staurosporine (apoptosis), glutamate (excitotoxicity), and hydrogen peroxide (necrosis/oxidative stress) revealed that NSC74429 at micromolar concentrations was the most neuroprotective. Subsequent testing in a rat model of asphyxial cardiac arrest, and in a mouse model of severe TBI, showed that serial dosing of 1 mg/kg of NSC74429 over 3 days improved hippocampal survival in both models. Taken together, NSC74429 is neuroprotective across multiple insult mechanisms. Future pharmacokinetic and pharmacodynamic (PK/PD) studies are warranted to optimize dosing, and mechanistic studies are needed to determine the percentage of neuroprotection mediated by PHLPP1/2 inhibition, or potentially from the modulation of PHLPP-independent targets.

Tackling Unmet Medical Need: How Slow-Release Intra-articular Corticosteroids Could Play a Role in Improving Quality of Life and Reducing Risk in Osteoarthritis

Osteoarthritis (OA) is the fastest growing cause of disability worldwide, but, with few proven therapeutic options, it is an underserved condition. With increasingly ageing populations contributing to a rising global prevalence, this unmet need only threatens to worsen in the coming years. To date, researchers have tried and failed in their bids to develop new ways to treat the pain and loss of function that significantly impacts health-related quality of life (HrQoL) and leaves people vulnerable to accumulating disability and at risk of cardiovascular disease (CVD), comorbidities, and mortality. Now, a novel way to deliver one of the only proven interventions for pain and inflammation, corticosteroid injections, is on the horizon for knee OA. Slow-release formulations could possibly prolong the clinical benefit of a single injection from 6 weeks to 6 months, providing a new option to improve HrQoL for people with OA, and maybe even breaking the cycle of inflammation that likely contributes to progression. In this key opinion leader article, Philip Conaghan and Lee Simon discuss OA’s significant Quality of life (QoL) and long-term health impact. They also outline the current, inadequate treatment landscape, and explain how slow-release corticosteroids could potentially help tackle a huge unmet medical need.

The extracellular matrix alteration, implication in modulation of drug resistance mechanism: friends or foes?

The extracellular matrix (ECM) is an important component of the tumor microenvironment (TME), having several important roles related to the hallmarks of cancer. In cancer, multiple components of the ECM have been shown to be altered. Although most of these alterations are represented by the increased or decreased quantity of the ECM components, changes regarding the functional alteration of a particular ECM component or of the ECM as a whole have been described. These alterations can be induced by the cancer cells directly or by the TME cells, with cancer-associated fibroblasts being of particular interest in this regard. Because the ECM has this wide array of functions in the tumor, preclinical and clinical studies have assessed the possibility of targeting the ECM, with some of them showing encouraging results. In the present review, we will highlight the most relevant ECM components presenting a comprehensive description of their physical, cellular and molecular properties which can alter the therapy response of the tumor cells. Lastly, some evidences regarding important biological processes were discussed, offering a more detailed understanding of how to modulate altered signalling pathways and to counteract drug resistance mechanisms in tumor cells.

Repurposing drugs to inhibit innate immune responses associated with TLR4, IL1, and NLRP3 signaling in joint cells

Osteoarthritis (OA) affects more than 300 million people worldwide and it is about to become the first disabling disease. OA is characterized by the progressive degradation of the articular cartilage but is a disease of the whole joint. Articular innate immune responses (IIR) associated with tissue degradation contribute to its progression. However, no treatment is available to block these IIRs. Through data text mining and computational pharmacology, we identified two clinical available drugs, naloxone, and thalidomide, with potential inhibitory properties on toll-like receptor 4 (TLR4), a major activator of these IIR. Proteome analysis confirmed that activation of this receptor or the IL1 receptor generated OA-like and gout-like proteomic changes in human primary chondrocytes. Both compounds were found to block TLR4 complex and inhibit TLR4 and IL1R-mediated IIR in OA chondrocytes, osteoblasts, and synoviocytes. Furthermore, naloxone and thalidomide inhibitory effects involved the downregulation of the NLRP3 inflammasome pathway, which is downstream of TLR4/IL1R signaling. We demonstrated that these compounds, within a therapeutic range of concentrations, exhibited anti-inflammatory and anti-catabolic properties in joint primary OA cells without any toxic effect. This data underpins naloxone & thalidomide repurpose to treat OA-associated inflammatory responses.

Developing and internally validating a prediction model for total knee replacement surgery in patients with osteoarthritis

Objective

The objective of this study was to develop and internally validate a clinical algorithm for use in general practice that predicts the probability of total knee replacement (TKR) surgery within the next five years for patients with osteoarthritis. The purpose of the model is to encourage early uptake of first-line treatment strategies in patients likely to undergo TKR and to provide a cohort for the development and testing of novel interventions that prevent or delay the progression to TKR.

Method

Electronic health records (EHRs) from 201,462 patients with osteoarthritis aged 45 years and over from 483 general practices across Australia were linked with records from the Australian Orthopaedic Association National Joint Replacement Registry and the National Death Index. A Fine and Gray competing risk prediction model was developed using these data to predict the risk of TKR within the next five years.

Results

During a follow-up time of 5 years, 15,979 (7.9%) patients underwent TKR and 13,873 (6.9%) died. Predictors included in the final algorithm were age, previous knee replacement, knee surgery (other than TKR), prescribing of osteoarthritis medication in the 12 months prior, comorbidity count and diagnosis of a mental health condition. Optimism corrected model discrimination was 0.67 (95% CI: 0.66 to 0.67) and model calibration acceptable.

Conclusion

The model has the potential to reduce some of the economic burden associated with TKR in Australia. External validation and further optimisation of the algorithm will be carried out prior to implementation within Australian general practice EHR systems.

A bovine nucleus pulposus explant culture model

Low back pain is a global health problem that is frequently caused by intervertebral disc degeneration (IVDD). Sulfated glycosaminoglycans (sGAGs) give the healthy nucleus pulposus (NP) a high fixed charge density (FCD), which creates an osmotic pressure that enables the disc to withstand high compressive forces. However, during IVDD sGAG reduction in the NP compromises biomechanical function. The aim of this study was to develop an ex vivo NP explant model with reduced sGAG content and subsequently investigate biomechanical restoration via injection of proteoglycan-containing notochordal cell-derived matrix (NCM). Bovine coccygeal NP explants were cultured in a bioreactor chamber and sGAG loss was induced by chondroitinase ABC (chABC) and cultured for up to 14 days. Afterwards, diurnal loading was studied, and explant restoration was investigated via injection of NCM. Explants were analyzed via histology, biochemistry, and biomechanical testing via stress relaxation tests and height measurements. ChABC injection induced dose-dependent sGAG reduction on Day 3, however, no dosing effects were detected after 7 and 14 days. Diurnal loading reduced sGAG loss after injection of chABC. NCM did not show an instant biomechanical (equilibrium pressure) or biochemical (FCD) restoration, as the injected fixed charges leached into the medium, however, NCM stimulated proliferation and increased Alcian blue staining intensity and matrix organization. NCM has biological repair potential and biomaterial/NCM combinations, which could better entrap NCM within the NP tissue, should be investigated in future studies. Concluding, chABC induced progressive, time-, dose- and loading-dependent sGAG reduction that led to a loss of biomechanical function. Keywords biomechanics | intervertebral disc | matrix degradation | low back pain | proteoglycans.

Predictors of Adherence to a Step Count Intervention Following Total Knee Replacement: An Exploratory Cohort Study

OBJECTIVE

To explore the person-level predictors of adherence to a step count intervention following total knee replacement (TKR).

DESIGN

Prospective cohort study, nested within the PATHway trial.

METHODS

Participants who had recently undergone TKR were recruited from 3 rehabilitation hospitals in Sydney, Australia, for the main trial. Only data from participants who were randomized to the TKR intervention group were analyzed. Participants in the intervention group (n = 51) received a wearable tracker to monitor the number of steps taken per day. Step count adherence was objectively measured at 3 months as the number of steps completed divided by the number prescribed and multiplied by 100 to express adherence as a percentage. Participants were classified into 4 groups: withdrawal, low adherence (0%-79%), adherent (80%-100%), and >100% adherent. Ordinal logistic regression was used to identify which factors predicted adherence to the prescribed step count.

RESULTS

Of the 51 participants enrolled, nine (18% of 51) withdrew from the study before 3 months. Half of participants were classified as >100% adherent (n = 24%, 47%). Ten were classified as low adherence (20%), and 8 participants were classified as adherent (16%). In the univariable model, lower age (OR 0.90; 95% CI 0.83-0.97), higher patient activation (OR 1.03; 95% CI 1.00-1.06), and higher technology self-efficacy (OR 1.03; 95% CI 1.00-1.06) were associated with higher adherence. After adjusting for age in the multivariable model, patient activation and technology self-efficacy were not significant.

CONCLUSION

Younger age, higher patient activation, and higher technology self-efficacy were associated with higher adherence to a step count intervention following TKR in the univariable model. Patient activation and technology self-efficacy were not associated with higher adherence following adjustment for age. J Orthop Sports Phys Ther 2022;52(9):620-629. Epub: 9 July 2022. doi:10.2519/jospt.2022.11133.

People With Knee Osteoarthritis Attending Physical Therapy Have Broad Education Needs and Prioritize Information About Surgery and Exercise: A Concept Mapping Study

OBJECTIVES

To (1) identify the education priorities of people with knee osteoarthritis, including perceived importance and confidence that a health care professional can address each, and (2) match priorities to education-specific content recommendations in knee osteoarthritis management guidelines.

DESIGN

Concept mapping methodology.

METHODS

Participants generated, sorted (based on themes), and rated (5-point Likert scales: importance and confidence) education priorities. Multidimensional scaling and hierarchical cluster analysis of sorting data produced a cluster map with overarching domains. Priorities were matched against education-specific content recommendations in knee osteoarthritis guidelines.

RESULTS

Participants (brainstorming, n = 43; sorting and rating, n = 24) generated 76 priorities. A 4-domain, 11-cluster map was the most useful representation of sorting data: (i) understanding treatment options (relationship of education and exercise with surgery, adjunct options, treatment decision making); (ii) exercise therapy (how to exercise, why exercise); (iii) understanding and managing the condition (symptom management, understanding symptoms, understanding the condition); and (4) surgical, medical, and dietary management (surgery, medications, diet and supplements). The "relationship of education and exercise with surgery" (3.88/5), "surgery" (3.86/5), and "how to exercise" (3.78/5) clusters were rated highest for importance. Few priorities identified by participants were clearly recommended as education-specific content recommendations in the American College of Rheumatology (3%, n = 2/76), European Alliance of Associations for Rheumatology (12%, n = 9/76), National Institute for Health and Care Excellence (16%, n = 12/76), and Osteoarthritis Research Society International (1%, n = 1/76) guidelines.

CONCLUSION

People with knee osteoarthritis presenting to physical therapists have broad education needs and prioritize information about surgery and exercise. J Orthop Sports Phys Ther 2022;52(9):595-606. Epub: 17 June 2022. doi:10.2519/jospt.2022.11089.

The association between anterior shoulder joint capsule thickening and glenoid deformity in primary glenohumeral osteoarthritis

BACKGROUND

Anterior shoulder joint capsule thickening is typically present in osteoarthritic shoulders, but its association with specific patterns of glenoid wear is incompletely understood. We sought to determine the relationship between anterior capsular thickening and glenoid deformity in primary glenohumeral osteoarthritis.

METHODS

We retrospectively identified 134 consecutive osteoarthritic shoulders with magnetic resonance imaging and computed tomography scans performed. Axial fat-suppressed magnetic resonance imaging slices were used to quantify the anterior capsular thickness in millimeters, measured at its thickest point below the subscapularis muscle. Computed tomography scans were used to classify glenoid deformity according to the Walch classification, and an automated 3-dimensional software program provided values for glenoid retroversion and humeral head subluxation. Multinomial and linear regression models were used to characterize the association of anterior capsular thickening with Walch glenoid type, glenoid retroversion, and posterior humeral head subluxation while controlling for patient age and sex.

RESULTS

The anterior capsule was thickest in glenoid types B2 (5.5 mm, 95% confidence interval [CI]: 5.0-6.0) and B3 (6.1 mm, 95% CI: 5.6-6.6) and thinnest in A1 (3.7 mm, 95% CI: 3.3-4.2; P < .001). Adjusted for age and sex, glenoid types B2 (odds ratio: 4.4, 95% CI: 2.3-8.4, P < .001) and B3 (odds ratio: 5.4, 95% CI: 2.8-10.4, P < .001) showed the strongest association with increased anterior capsule thickness, compared to glenoid type A1. Increased capsular thickness correlated with greater glenoid retroversion (r = 0.57; P < .001) and posterior humeral head subluxation (r = 0.50; P < .001). In multivariable analysis, for every 1-mm increase in anterior capsular thickening, there was an adjusted mean increase of 3.2° (95% CI: 2.4-4.1) in glenoid retroversion and a 3.8% (95% CI: 2.7-5.0) increase in posterior humeral head subluxation.

CONCLUSIONS

Increased thickening of the anterior shoulder capsule is associated with greater posterior glenoid wear and humeral head subluxation. Additional research should determine whether anterior capsular disease plays a causative role in the etiology or progression of eccentric glenohumeral osteoarthritis.

"Much better than I thought it was going to be": Telehealth delivered group-based education and exercise was perceived as acceptable among people with knee osteoarthritis

Objective

To understand patient perceived acceptability of participating in a telehealth delivered group-based education and exercise-therapy program for knee osteoarthritis.

Design

This qualitative study involved semi-structured, one-on-one interviews with knee osteoarthritis patients who have completed the Good Living with osteoArthritis from Denmark (GLA:D®) program via telehealth or in-person. Interviews were recorded, transcribed verbatim, coded, and analysed using an inductive content analysis approach, focusing on themes related to telehealth.

Results

Nineteen participants [12 (63%) female, mean aged 62 years, range 49-72 years] were included. Eleven (58%) received GLA:D® via telehealth and 8 (42%) attended in-person sessions. Two overarching themes (6 sub-themes) related to telehealth perceived acceptability were identified: 1) Perceptions of telehealth acceptability was highly influenced by exposure. Individuals who had received telehealth considered it easy, convenient, and flexible, whereas telehealth was perceived to be inferior and misunderstood by those without exposure. 2) Telehealth participants reported similar program benefits to in-person participants, including reduced fear of pain and joint damage, changed beliefs in value of exercise, and stated improvements in pain and function.

Conclusions

Telehealth delivery of group-based education and exercise-therapy for knee osteoarthritis was acceptable for people who had experienced it and provides similar benefits as in-person care for pain and beliefs about the safety and value of exercise. Wider implementation of telehealth group-based education and exercise-therapy may improve access to high value care for people with knee osteoarthritis.

Physical Therapists Prioritize Providing Education About Exercise Therapy and to Dispel Misconceptions About Radiology for People With Knee Osteoarthritis: A Concept Mapping Study

OBJECTIVE

To (1) identify the education priorities that physical therapists have for people with knee osteoarthritis, including perceived importance and capability to provide, and (2) match priorities to education-specific content recommendations in knee osteoarthritis guidelines.

DESIGN

Concept mapping methodology.

METHODS

Physical therapists generated, sorted (based on themes), and rated (5-point Likert scales: importance and capability) patient education priorities. Priorities were matched against education-specific content recommendations in knee osteoarthritis guidelines. Additional education-specific content recommendations were added from guidelines and expert opinion if necessary. Multidimensional scaling and hierarchical cluster analysis produced a cluster map with overarching domains.

RESULTS

Physical therapists (brainstorming, n = 41; sorting, n = 20; rating, n = 22) generated 56 priorities, with 13 added (n = 2 from guidelines, n = 11 from expert opinion). Few priorities were clearly included as education-specific content recommendations in guidelines (ACR [2%, n = 1/56], EULAR [14%, 8/56], NICE [11%, 6/56], and OARSI [0%, 0/56]). An 8-cluster map emerged with 3 overarching domains: (i) first-line care (exercise therapy, lifestyle modification and general health, and weight management), (ii) knowledge formation and countering misconceptions (radiology misconceptions, understanding and managing pain and disability, and general beliefs and understanding about osteoarthritis), and (iii) decision making for medical management (surgery and medications). The exercise therapy cluster was rated the highest for both importance (3.84/5) and capability (4.00). The medications and weight management clusters were rated the lowest for importance (2.54) and capability (2.82), respectively.

CONCLUSION

Physical therapists prioritize a range of education topics for people with knee osteoarthritis, focusing on exercise therapy. Physical therapists feel least capable of providing weight management education. J Orthop Sports Phys Ther 2022;52(9):607-619. Epub: 17 June 2022. doi:10.2519/jospt.2022.11090.

The alarmins high mobility group box protein 1 and S100A8/A9 display different inflammatory profiles after acute knee injury

OBJECTIVE

To compare the concentrations of high mobility group box 1 protein (HMGB1) and S100A8/A9 in synovial fluid between patients with knee injuries and osteoarthritis (OA), and knee healthy subjects. To investigate associations of alarmin levels with different joint injuries and with biomarkers of inflammation, Wnt signaling, complement system, bone and cartilage degradation.

METHODS

HMGB1 and S100A8/A9 were measured in synovial fluid by immunoassays in patients with knee injuries, with OA and from knee healthy subjects, and were related to time from injury and with biomarkers obtained from previous studies. Hierarchical cluster and enrichment analyses of biomarkers associated to HMGB1 and S100A8/A9 were performed.

RESULTS

The synovial fluid HMGB1 and S100A8/A9 concentrations were increased early after knee injury; S100A8/A9 levels were negatively associated to time after injury and was lower in the old compared to recent injury group, while HMGB1 was not associated to time after injury. The S100A8/A9 levels were also increased in OA. The initial inflammatory response was similar between the alarmins, and HMGB1 and S100A8/A9 shared 9 out of 20 enriched pathways. The alarmins displayed distinct response profiles, HMGB1 being associated to cartilage biomarkers while S100A8/A9 was associated to proinflammatory cytokines.

CONCLUSIONS

HMGB1 and S100A8/A9 are increased as an immediate response to knee trauma. While they share many features in inflammatory and immunoregulatory mechanisms, S100A8/A9 and HMGB1 are associated to different downstream responses, which may have impact on the OA progression after acute knee injuries.

Are Income-based Differences in TKA Use and Outcomes Reduced in a Single-payer System? A Large-database Comparison of the United States and Canada

BACKGROUND

Income-based differences in the use of and outcomes in TKA have been studied; however, it is not known if different healthcare systems affect this relationship. Although Canada's single-payer healthcare system is assumed to attenuate the wealth-based differences in TKA use observed in the United States, empirical cross-border comparisons are lacking.

QUESTIONS/PURPOSES

(1) Does TKA use differ between Pennsylvania, USA, and Ontario, Canada? (2) Are income-based disparities in TKA use larger in Pennsylvania or Ontario? (3) Are TKA outcomes (90-day mortality, 90-day readmission, and 1-year revision rates) different between Pennsylvania and Ontario? (4) Are income-based disparities in TKA outcomes larger in Pennsylvania or Ontario?

METHODS

We identified all patients hospitalized for primary TKA in this cross-border retrospective analysis, using administrative data for 2012 to 2018, and we found a total of 161,244 primary TKAs in Ontario and 208,016 TKAs in Pennsylvania. We used data from the Pennsylvania Health Care Cost Containment Council, Harrisburg, PA, USA, and the ICES (formally the Institute for Clinical Evaluative Sciences), Toronto, Ontario, Canada. We linked patient-level data to the respective census data to determine community-level income using ZIP Code or postal code of residence and stratified patients into neighborhood income quintiles. We compared TKA use (age and gender, standardized per 10,000 population per year) for patients residing in the highest-income versus the lowest-income quintile neighborhoods. Similarly secondary outcomes 90-day mortality, 90-day readmission, and 1-year revision rates were compared between the two regions and analyzed by income groups.

RESULTS

TKA use was higher in Pennsylvania than in Ontario overall and for all income quintiles (lowest income quartile: 31 versus 18 procedures per 10,000 population per year; p < 0.001; highest income quartile: 38 versus 23 procedures per 10,000 population per year; p < 0.001). The relative difference in use between the highest-income and lowest-income quintile was larger in Ontario (28% higher) than in Pennsylvania (23% higher); p < 0.001. Patients receiving TKA in Pennsylvania were more likely to be readmitted within 90 days and were more likely to undergo revision within the first year than patients in Ontario, but there was no difference in mortality at 1 year. When comparing income groups, there were no differences between the countries in 90-day mortality, readmission, or 1-year revision rates (p > 0.05).

CONCLUSION

These results suggest that universal health insurance through a single-payer may not reduce the income-based differences in TKA access that are known to exist in the United States. Future studies are needed determine if our results are consistent across other geographic regions and other surgical procedures.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Characterization of Migratory Cells From Bioengineered Bovine Cartilage in a 3D Co-culture Model

BACKGROUND

Chondrocyte migration in native cartilage is limited and has been implicated as one of the reasons for the poor integration of native implants. Through use of an in vitro integration model, it has previously been shown that cells from bioengineered cartilage can migrate into the native host cartilage during integration. Platelet-rich plasma (PRP) treatment further enhanced integration of bioengineered cartilage to native cartilage in vitro. However, it is not known how PRP treatment of the bioengineered construct promotes this.

HYPOTHESIS

PRP supports cell migration from bioengineered cartilage and these migratory cells have the ability to accumulate cartilage-like matrix.

STUDY DESIGN

Controlled laboratory study.

METHODS

Osteochondral-like constructs were generated by culturing primary bovine chondrocytes on the top surface of a porous bone substitute biomaterial composed of calcium polyphosphate. After 1 week in culture, the constructs were submerged in PRP and placed adjacent, but 2 mm distant, to a native bovine osteochondral plug in a co-culture model for 2 weeks. Cell migration was monitored using phase-contrast imaging. Cell phenotype was determined by evaluating the gene expression of matrix metalloprotease 13 (MMP-13), Ki67, and cartilage matrix molecules using quantitative polymerase chain reaction. When tissue formed, it was assessed by histology, immunohistochemistry, and quantification of matrix content.

RESULTS

PRP treatment resulted in the formation of a fiber network connecting the bioengineered cartilage and native osteochondral plug. Cells from both the bioengineered cartilage and the native osteochondral tissue migrated onto the PRP fibers and formed a tissue bridge after 2 weeks of culture. Migratory cells on the tissue bridge expressed higher levels of collagen types II and I (COL2, COL1), Ki67 and MMP-13 mRNA compared with nonmigratory cells in the bioengineered cartilage. Ki67 and MMP-13-positive cells were found on the edges of the tissue bridge. The tissue bridge accumulated COL1 and COL2 and aggrecan and contained comparable collagen and glycosaminoglycan content to the bioengineered cartilage matrix. The tissue bridge did not reliably develop in the absence of cells from the native osteochondral plug.

CONCLUSION

Bioengineered cartilage formed by bovine chondrocytes contains cells that can migrate on PRP fibers and form cartilaginous tissue.

CLINICAL RELEVANCE

Migratory cells from bioengineered cartilage may promote cartilage integration. Further studies are required to determine the role of migratory cells in integration in vivo.

Clinical practice recommendations for prehabilitation and post-operative rehabilitation for arthroplasty: A scoping review

BACKGROUND

The rising need for arthroplasty (joint replacement) has resulted in a significant increase in wait-times. Longer surgical wait-times may further exacerbate functional decline in adults with osteoarthritis as well as delay postoperative functional recovery. This review aims to better inform rehabilitation care provision before (prehabilitation) and after (post-rehabilitation) hip or knee arthroplasty based on recommendations from clinical practice guidelines (CPGs).

METHODS

This scoping review used a three-stage process to screen and extract articles, which resulted in 123 articles reviewed for analysis. Included CPGs were in the English language and focussed on rehabilitation interventions or practices involving adult patients preparing for or recuperating from hip and knee arthroplasty (published 2009-2020).

RESULTS

Patient assessments, use of assistive devices, as well as self-management and education programs were recommended before and after arthroplasty. Physiotherapy was recommended to support post-operative rehabilitation. Conversely, there was limited evidence supporting recommendations for or against physiotherapy during the prehabilitation phase of the arthroplasty care journey.

CONCLUSIONS

The findings from this review highlight the current gap in high-quality evidence supporting hip and knee arthroplasty rehabilitation CPGs before and after surgery. Findings warrant additional research to ensure patients are best prepared for surgery and supported for optimal recovery.

Isothermal circular strand displacement-based assay for microRNA detection in liquid biopsy

Extracellular miRNAs are promising targets for developing new assays for the early diagnosis and prognosis of diseases based on liquid biopsy. The detection of miRNAs in liquid biopsies is challenged by their short sequence length, low concentration, and interferences with bodily fluid components. Isothermal circular strand displacement polymerization has emerged as a convenient method for nucleic acid amplification and detection. Herein, we describe an innovative strategy for microRNA detection directly from biological fluids based on hairpin probe-assisted isothermal amplification reaction. We designed and optimized the assay to detect target analytes in 1 µL of the complex media's biological matrix using a microfluidic device for the straightforward analysis of multiple samples. We validated the assay to detect circulating miR-127-5p in synovial fluid, recently indicated as a predictive biomarker for osteoarthritis disease. The combined use of a mutant polymerase operating with high yield and a primer incorporating locked nucleic acid nucleosides allowed detection of miR-127-5p with 34 fmol L-1 LOD. We quantified circulating miR-127-5p directly in synovial fluid, thus demonstrating that the assay may be employed for the convenient detection of 4.3 ± 0.5 pmol L-1 concentrated miRNAs in liquid biopsy samples.

Association of presurgical circulating MicroRNAs with 1-year postsurgical pain reduction in spine facet osteoarthritis patients with lumbar spinal stenosis

Purpose

Up to 30% of spine facet osteoarthritis patients with lumbar spinal stenosis (SF-OA ​+ ​LSS) have little to no improvement in their pain after surgery. Lack of meaningful improvement in pain following surgery provides a unique opportunity to identify specific predictive biomarker signatures that might be associated with the outcomes of surgical treatment. The objective of the present study was to determine whether a microRNA (miRNA) biomarker signature could be identified in presurgical blood plasma that corresponded with levels of SF-OA ​+ ​LSS patient post-surgical pain intensity one year later.

Methods

RNA was extracted from baseline plasma of SF-OA ​+ ​LSS patients and prepared for miRNA sequencing. Statistical approaches were performed to identify differentially expressed miRNAs associated with reduced 1-year postsurgical pain (n ​= ​56). Using an integrated computational approach, we further created predicted gene and pathway networks for each identified miRNA.

Results

We identified a panel of 4 circulating candidate miRNAs (hsa-miR-155-5p, hsa-let-7e-5p, hsa-miR-125a-5p, hsa-miR-99b-5p) with higher levels at presurgical baseline that were associated with greater changes in % NPRS20Δ, reflecting reduced pain intensity levels at one year. Genes encoding hsa-let-7e-5p, hsa-miR-125a-5p, and hsa-miR-99b-5p are part of an evolutionarily conserved miRNA cluster. Using integrated computational analyses, we showed that mammalian target of rapamycin, transforming growth factor-β1 receptor, Wnt signaling, epithelial-mesenchymal transition regulators, and cholecystokinin signaling were enriched pathways of predicted gene targets.

Conclusions

Taken together, our findings suggest that 4 presurgical baseline circulating miRNAs correlate with 1-year postsurgical SF-OA ​+ ​LSS patient pain intensity and represent possible candidate biomarker signature of surgical pain response.

Clinical monitoring in osteoarthritis: Biomarkers

OBJECTIVE

The purpose of this overview of osteoarthritis (OA) biomarkers is to provide the non-specialist with a toolbox, based on experience acquired by biomarker researchers over many years, to understand biomarkers in general and their use in the OA field.

METHODS

We provide an update on this subject since the OARSI Primer on osteoarthritis (OA) nearly a decade ago.

RESULTS

Since the last update, the importance of molecular biomarkers has been increasingly recognized in the field, but no OA-related biomarkers have been adopted for routine use in clinical practice. The current lack of chondroprotective treatments for OA impairs the assessment, validation and qualification of the potential role of biomarkers as tools for monitoring disease status and patient responses to treatment of OA. Yet there is no lack of an evolving compendium of OA-related biomarkers, ever more fit-for-purpose, that could currently facilitate drug development for OA. We provide an abbreviated update and overview of specific soluble OA-related biomarkers for this new OARSI Primer on OA with OA-relevant examples encompassing the concepts of biomarker nomenclature, qualification, interpretation, measurement, reporting requirements, application to research, drug discovery and clinical care, and future needs for biomarker advancement.

CONCLUSION

Appropriate biomarkers should play a role at all stages of OA diagnosis, prognosis, drug development, and treatment. The future of OA biomarker research and development holds great promise as its foundation is increasingly robust.

Relationship Between Knee Biomechanics and Pain in People With Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

Our primary aim was to determine the cross-sectional relationship between knee biomechanics during gait and pain in people with medial knee osteoarthritis. Our secondary aim was to evaluate differences in knee biomechanics between symptomatic and asymptomatic participants with medial knee osteoarthritis.

METHODS

Four online databases were searched from inception to July 2021. Eligible studies included people with medial/nonspecific knee osteoarthritis and a reported relationship between knee biomechanics during gait and pain or biomechanics of symptomatic and asymptomatic participants. Two reviewers independently extracted data and evaluated risk of bias. Random-effects meta-analyses were performed when three or more studies reported the same biomechanical variable for pooling (knee adduction moment [KAM], KAM impulse, varus thrust, and peak knee flexion moment [KFM]).

RESULTS

Forty studies were included. Methodological quality ranged from 4 to 9/10. Forty-seven unique biomechanical variables were reported. For the KAM, there was no correlation with pain for peak values pooled (early stance and overall) (r = 0.00, 95% confidence interval [95% CI]: -0.12, 0.11, k = 16), a small negative correlation for early stance peak alone (r = -0.09, 95% CI -0.18, -0.002, k = 12), and a medium positive correlation for the overall peak during stance (r = 0.30, 95% CI 0.17, 0.42, k = 4). Metaregression identified that body mass index moderated the peak KAM-pain relationship (P < 0.001). KAM impulse had a small positive correlation with pain (r = 0.23, 95% CI 0.04, 0.40, k = 5), and people with varus thrust had 3.84 greater odds of reporting pain compared with people without (95% CI 1.72, 8.53, k = 3). Meta-analyses for the peak KFM and pain correlation and secondary aim were nonsignificant.

CONCLUSION

Some knee gait biomechanics were associated with pain in this cohort. Longitudinal studies are required to determine causality.

Patients' perspectives on the benefits of feedback on patient-reported outcome measures in a web-based personalized decision report for hip and knee osteoarthritis

BACKGROUND

Applications of patient-reported outcome measures (PROMs) for individual patient management are expanding with the support of digital tools. Providing PROM-based information to patients can potentially improve care experiences and outcomes through informing and activating patients. This study explored patients' perspectives on the benefits of receiving feedback on PROMs in the context of a web-based personalized decision report to guide care for their hip or knee osteoarthritis.

METHODS

This qualitative descriptive interview study was nested in a pragmatic clinical trial of a personalized report, which includes descriptive PROM scores and predicted postoperative PROM scores. Patients completed a semi-structured interview within 6 weeks of an office visit with an orthopaedic surgeon. Only patients who reported receiving the report and reviewing it with the surgeon and/or a health educator were included. Data were iteratively analyzed using a combination of deductive and inductive coding strategies.

RESULTS

Twenty-five patients aged 49-82 years (60% female, 72% surgical treatment decision) participated and described three primary benefits of the PROM feedback within the report: 1. Gaining Information About My Health Status, including data teaching new information, confirming what was known, or providing a frame of reference; 2. Fostering Communication Between Patient and Surgeon, encompassing use of the data to set expectations, ask and answer questions, and facilitate shared understanding; and 3. Increasing My Confidence and Trust, relating to the treatment outcomes, treatment decision, and surgeon.

CONCLUSIONS

Patients identified actual and hypothetical benefits of receiving feedback on PROM scores in the context of a web-based decision report, including advantages for those who had already made a treatment decision before seeing the surgeon. Findings provide insight into patients' perspectives on how digital PROM data can promote patient-centered care. Results should be considered in the context of the homogeneous sample and complex trial. While participants perceived value in this personalized report, questions remain regarding best practices in patient-facing data presentation and engagement.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03102580. Registered on 5 April 2017.

Isometric Quadriceps Exercises for Patients with Knee Osteoarthritis: A Randomized Controlled Trial Comparing Knee Joint Position Flexion versus Extension

Objective

To compare the effect of quadriceps isometric exercises performed in two different positions in addition to the combined physical therapy program on pain, stiffness, and physical function in patients with knee osteoarthritis (OA).

Methods

A total of 30 patients with OA (age range 45 to 70 years) who were admitted to Istanbul Private Ekotom Medical Center, Department of Physical Medicine and Rehabilitation Outpatient Clinic, were included. The patients were randomly divided into two groups according to the type of performing the quadriceps isometric exercises as group 1 (performing in knee extension, n = 14) and group 2 (performing in knee flexion, n = 15). All patients also received a combined physical therapy program. Exercise protocols were applied six days a week for four weeks. The pain was evaluated using a 10 cm visual analog scale for pain (VAS) in rest and activity; pain, joint stiffness, and physical function were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

Results

A significant difference was found in the VAS and WOMAC scores of both groups in group comparisons (p < 0.05). When the groups were compared in terms of change values, a significant difference was found in the WOMAC stiffness score in favor of group I (p < 0.05). Discussion. It is possible to obtain positive results with quadriceps isometric exercises to reduce pain and joint stiffness and increase physical function in patients with knee OA. However, exercises performed in knee extension were found to be more effective in reducing joint stiffness.

Associations of plasma miRNAs with waist circumference and insulin resistance among women with polycystic ovary syndrome - Pilot study

BACKGROUND

Insulin resistance (IR) and central obesity are common in polycystic ovary syndrome (PCOS), but pathomechanisms for IR in PCOS are not established. Circulating microRNAs (miRNAs) are non-invasive biomarkers of epigenetic regulation that may contribute to the pathogenesis of IR and central adiposity in PCOS.

METHODS

We conducted a pilot study to examine associations of circulating miRNAs with IR and central adiposity among women with PCOS (n = 11) using high-throughput miRNA sequencing. We fit generalized linear models examining associations of waist circumference and HOMA-IR with plasma miRNAs. We used false discovery rate (FDR)-adjusted cutoff p < 0.1 to correct for multiple testing. We used miRDB's Gene Ontology (GO) tool to identify predicted pathways for top hits.

RESULTS

Mean age and BMI of participants were 27.9 years and 32.5 kg/m2, respectively. Lower levels of miR-1294 were associated with higher waist circumference (β = -0.10, FDR = 0.095). While no miRNAs were associated with HOMA-IR at our FDR cut off <0.1, 11 miRNAs were associated with waist circumference and 14 miRNAs with HOMA-IR at unadjusted p < 0.01, including members of the highly conserved miR-17/92 cluster and miR-1294 (β = -0.10, p < 0.001). The GO analysis of miR-1294 identified 54 overrepresented pathways, including "negative regulation of insulin receptor signaling" (FDR = 0.019), and 6 underrepresented pathways.

CONCLUSIONS

Plasma miR-1294 along with members of the miR-17/92 cluster and miRNAs involved in insulin signaling may be associated with central obesity and insulin resistance in PCOS. Larger studies among women with and without PCOS are needed to validate these findings.

Potential Satellite Cell-Linked Biomarkers in Aging Skeletal Muscle Tissue: Proteomics and Proteogenomics to Monitor Sarcopenia

Sarcopenia (Sp) is the loss of skeletal muscle mass associated with aging which causes an involution of muscle function and strength. Satellite cells (Sc) are myogenic stem cells, which are activated by injury or stress, and repair muscle tissue. With advancing age, there is a decrease in the efficiency of the regenerative response of Sc. Diagnosis occurs with the Sp established by direct assessments of muscle. However, the detection of biomarkers in real-time biofluids by liquid biopsy could represent a step-change in the understanding of the molecular biology and heterogeneity of Sp. A total of 13 potential proteogenomic biomarkers of Sp by their physiological and biological interaction with Sc have been previously described in the literature. Increases in the expression of GDF11, PGC-1α, Sirt1, Pax7, Pax3, Myf5, MyoD, CD34, MyoG, and activation of Notch signaling stimulate Sc activity and proliferation, which could modulate and delay Sp progression. On the contrary, intensified expression of GDF8, p16INK4a, Mrf4, and activation of the Wnt pathway would contribute to early Sp development by directly inducing reduced and/or altered Sc function, which would attenuate the restorative capacity of skeletal muscle. Additionally, tissue biopsy remains an important diagnostic tool. Proteomic profiling of aged muscle tissues has shown shifts toward protein isoforms characteristic of a fast-to-slow transition process and an elevated number of oxidized proteins. In addition, a strong association between age and plasma values of growth differentiation factor 15 (GDF-15) has been described and serpin family A member 3 (serpin A3n) was more secreted by atrophied muscle cells. The identification of these new biomarkers holds the potential to change personalized medicine because it could predict in real time the course of Sp by monitoring its evolution and assessing responses to potential therapeutic strategies.

Dose-response relationship of in vivo ambulatory load and mechanosensitive cartilage biomarkers-The role of age, tissue health and inflammation: A study protocol

OBJECTIVE

To describe a study protocol for investigating the in vivo dose-response relationship between ambulatory load magnitude and mechanosensitive blood markers of articular cartilage, the influence of age, cartilage tissue health and presence of inflammation on this relationship, and its ability to predict changes in articular cartilage quality and morphology within 2 years.

DESIGN

Prospective experimental multimodal (clinical, biomechanical, biological) data collection under walking stress and three different load conditions varied in a randomized crossover design.

EXPERIMENTAL PROTOCOL

At baseline, equal numbers of healthy and anterior cruciate ligament injured participants aged 20-30 or 40-60 years will be assessed clinically and complete questionnaires regarding their knee health. Biomechanical parameters (joint kinetics, joint kinematics, and surface electromyography) will be recorded while performing different tasks including overground and treadmill walking, single leg balance and hopping tasks. Magnetic resonance images (MRI) of both of knees will be obtained. On separate stress test days, participants will perform a 30-minute walking stress with either reduced (80% body weight (BW)), normal (100%BW) or increased (120%BW) load. Serum blood samples will be taken immediately before, immediately after, 30, 120 and 210 minutes after the walking stress. Concentration of articular cartilage blood biomarkers will be assessed using enzyme linked immunosorbent assays. At 24-month follow-up, participants will be again assessed clinically, undergo an MRI, complete questionnaires, and have a blood sample taken.

CONCLUSION

The study design provides a standardized set up that allows to better understand the influence of ambulatory load on articular cartilage biomarkers and thereby extend current knowledge on in vivo cartilage metabolism and mechanosensitivity. Further, this study will help to elucidate the prognostic value of the load-induced cartilage biomarker response for early articular cartilage degeneration.

TRIAL REGISTRATION

The protocol was approved by the regional ethics committee and has been registered at clinicaltrials.gov (NCT04128566).

Inflammatory cytokines and mechanical injury induce post-traumatic osteoarthritis-like changes in a human cartilage-bone-synovium microphysiological system

BACKGROUND

Traumatic knee injuries in humans trigger an immediate increase in synovial fluid levels of inflammatory cytokines that accompany impact damage to joint tissues. We developed a human in vitro cartilage-bone-synovium (CBS) coculture model to study the role of mechanical injury and inflammation in the initiation of post-traumatic osteoarthritis (PTOA)-like disease.

METHODS

Osteochondral plugs (cartilage-bone, CB) along with joint capsule synovium explants (S) were harvested from 25 cadaveric distal femurs from 16 human donors (Collin's grade 0-2, 23-83years). Two-week monocultures (cartilage (C), bone (B), synovium (S)) and cocultures (CB, CBS) were established. A PTOA-like disease group was initiated via coculture of synovium explants with mechanically impacted osteochondral plugs (CBS+INJ, peak stress 5MPa) with non-impacted CB as controls. Disease-like progression was assessed through analyses of changes in cell viability, inflammatory cytokines released to media (10-plex ELISA), tissue matrix degradation, and metabolomics profile.

RESULTS

Immediate increases in concentrations of a panel of inflammatory cytokines occurred in CBS+INJ and CBS cocultures and cultures with S alone (IL-1, IL-6, IL-8, and TNF-α among others). CBS+INJ and CBS also showed increased chondrocyte death compared to uninjured CB. The release of sulfated glycosaminoglycans (sGAG) and associated ARGS-aggrecan neoepitope fragments to the medium was significantly increased in CBS and CBS+INJ groups. Distinct metabolomics profiles were observed for C, B, and S monocultures, and metabolites related to inflammatory response in CBS versus CB (e.g., kynurenine, 1-methylnicotinamide, and hypoxanthine) were identified.

CONCLUSION

CBS and CBS+INJ models showed distinct cellular, inflammatory, and matrix-related alterations relevant to PTOA-like initiation/progression. The use of human knee tissues from donors that had no prior history of OA disease suggests the relevance of this model in highlighting the role of injury and inflammation in earliest stages of PTOA progression.