The ability to edit DNA at the nucleotide level using clustered regularly interspaced short palindromic repeats (CRISPR) systems is a relatively new investigative tool that is revolutionizing the analysis of many aspects of human health and disease, including orthopaedic disease. CRISPR, adapted for mammalian cell genome editing from a bacterial defence system, has been shown to be a flexible, programmable, scalable, and easy-to-use gene editing tool. Recent improvements increase the functionality of CRISPR through the engineering of specific elements of CRISPR systems, the discovery of new, naturally occurring CRISPR molecules, and modifications that take CRISPR beyond gene editing to the regulation of gene transcription and the manipulation of RNA. Here, the basics of CRISPR genome editing will be reviewed, including a description of how it has transformed some aspects of molecular musculoskeletal research, and will conclude by speculating what the future holds for the use of CRISPR-related treatments and therapies in clinical orthopaedic practice. Cite this article: Bone Joint Res 2020;9(7):351–359

Cite this article: Bone Joint Res 2023;12(4):256–258.

Objectives. As tumours of bone and soft tissue are rare, multicentre prospective collaboration is essential for meaningful research and evidence-based advances in patient care. The aim of this study was to identify barriers and facilitators encountered in large-scale collaborative research by orthopaedic oncological surgeons involved or interested in prospective multicentre collaboration. Methods. All surgeons who were involved, or had expressed an interest, in the ongoing Prophylactic Antibiotic Regimens in Tumour Surgery (PARITY) trial were invited to participate in a focus group to discuss their experiences with collaborative research in this area. The discussion was digitally recorded, transcribed and anonymised. The transcript was analysed qualitatively, using an analytic approach which aims to organise the data in the language of the participants with little theoretical interpretation. Results. The 13 surgeons who participated in the discussion represented orthopaedic oncology practices from seven countries (Argentina, Brazil, Italy, Spain, Denmark, United States and Canada). Four categories and associated themes emerged from the discussion: the need for collaboration in the field of orthopaedic oncology due to the rarity of the tumours and the need for high level evidence to guide treatment; motivational factors for participating in collaborative research including establishing proof of principle, learning opportunity, answering a relevant research question and being part of a collaborative research community; barriers to participation including funding, personal barriers, institutional barriers, trial barriers, and administrative barriers and facilitators for participation including institutional facilitators, leadership, authorship, trial set-up, and the support of centralised study coordination. Conclusions. Orthopaedic surgeons involved in an ongoing international randomised controlled trial (RCT) were motivated by many factors to participate. There were a number of barriers to and facilitators for their participation. There was a collective sense of fatigue experienced in overcoming these barriers, which was mirrored by a strong collective sense of the importance of, and need for, collaborative research in this field. The experiences were described as essential educational first steps to advance collaborative studies in this area. Knowledge gained from this study will inform the development of future large-scale collaborative research projects in orthopaedic oncology. Cite this article: J. S. Rendon, M. Swinton, N. Bernthal, M. Boffano, T. Damron, N. Evaniew, P. Ferguson, M. Galli Serra, W. Hettwer, P. McKay, B. Miller, L. Nystrom, W. Parizzia, P. Schneider, A. Spiguel, R. Vélez, K. Weiss, J. P. Zumárraga, M. Ghert. Barriers and facilitators experienced in collaborative prospective research in orthopaedic oncology: A qualitative study. Bone Joint Res 2017;6:–314. DOI: 10.1302/2046-3758.65.BJR-2016-0192.R1

Objectives. Despite the fact that research fraud and misconduct are under scrutiny in the field of orthopaedic research, little systematic work has been done to uncover and characterise the underlying reasons for academic retractions in this field. The purpose of this study was to determine the rate of retractions and identify the reasons for retracted publications in the orthopaedic literature. Methods. Two reviewers independently searched MEDLINE, EMBASE, and the Cochrane Library (1995 to current) using MeSH keyword headings and the ‘retracted’ filter. We also searched an independent website that reports and archives retracted scientific publications (. www.retractionwatch.com. ). Two reviewers independently extracted data including reason for retraction, study type, journal impact factor, and country of origin. Results. One hundred and ten retracted studies were included for data extraction. The retracted studies were published in journals with impact factors ranging from 0.000 (discontinued journals) to 13.262. In the 20-year search window, only 25 papers were retracted in the first ten years, with the remaining 85 papers retracted in the most recent decade. The most common reasons for retraction were fraudulent data (29), plagiarism (25) and duplicate publication (20). Retracted articles have been cited up to 165 times (median 6; interquartile range 2 to 19). Conclusion. The rate of retractions in the orthopaedic literature is increasing, with the majority of retractions attributed to academic misconduct and fraud. Orthopaedic retractions originate from numerous journals and countries, indicating that misconduct issues are widespread. The results of this study highlight the need to address academic integrity when training the next generation of orthopaedic investigators. Cite this article: J. Yan, A. MacDonald, L-P. Baisi, N. Evaniew, M. Bhandari, M. Ghert. Retractions in orthopaedic research: A systematic review. Bone Joint Res 2016;5:263–268. DOI: 10.1302/2046-3758.56.BJR-2016-0047

Objectives. One commonly used rat fracture model for bone and mineral research is a closed mid-shaft femur fracture as described by Bonnarens in 1984. Initially, this model was believed to create very reproducible fractures. However, there have been frequent reports of comminution and varying rates of complication. Given the importance of precise anticipation of those characteristics in laboratory research, we aimed to precisely estimate the rate of comminution, its importance and its effect on the amount of soft callus created. Furthermore, we aimed to precisely report the rate of complications such as death and infection. Methods. We tested a rat model of femoral fracture on 84 rats based on Bonnarens’ original description. We used a proximal approach with trochanterotomy to insert the pin, a drop tower to create the fracture and a high-resolution fluoroscopic imager to detect the comminution. We weighed the soft callus on day seven and compared the soft callus parameters with the comminution status. Results. The mean operating time was 34.8 minutes (. sd. 9.8). The fracture was usable (transverse, mid-shaft, without significant comminution and with displacement < 1 mm) in 74 animals (88%). Of these 74 usable fractures, slight comminution was detected in 47 (63%). In 50 animals who underwent callus manipulation, slight comminution (n = 32) was statistically correlated to the amount of early callus created (r = 0.35, p = 0.015). Two complications occurred: one death and one deep infection. Conclusions. We propose an accurate description of comminution and complications in order to improve experiments on rat femur fracture model in the field of laboratory research. Cite this article: Bone Joint Res 2013;2:149–54

Objectives. Evidence -based medicine (EBM) is designed to inform clinical decision-making within all medical specialties, including orthopaedic surgery. We recently published a pilot survey of the Canadian Orthopaedic Association (COA) membership and demonstrated that the adoption of EBM principles is variable among Canadian orthopaedic surgeons. The objective of this study was to conduct a broader international survey of orthopaedic surgeons to identify characteristics of research studies perceived as being most influential in informing clinical decision-making. Materials and Methods. A 29-question electronic survey was distributed to the readership of an established orthopaedic journal with international readership. The survey aimed to analyse the influence of both extrinsic (journal quality, investigator profiles, etc.) and intrinsic characteristics (study design, sample size, etc.) of research studies in relation to their influence on practice patterns. Results. A total of 353 surgeons completed the survey. Surgeons achieved consensus on the ‘importance’ of three key designs on their practices: randomised controlled trials (94%), meta-analyses (75%) and systematic reviews (66%). The vast majority of respondents support the use of current evidence over historical clinical training; however subjective factors such as journal reputation (72%) and investigator profile (68%) continue to influence clinical decision-making strongly. Conclusion. Although intrinsic factors such as study design and sample size have some influence on clinical decision-making, surgeon respondents are equally influenced by extrinsic factors such as investigator reputation and perceived journal quality. Cite this article: Dr M. Ghert. An international survey to identify the intrinsic and extrinsic factors of research studies most likely to change orthopaedic practice. Bone Joint Res 2016;5:130–136. DOI: 10.1302/2046-3758.54.2000578

Tendinopathy is a debilitating musculoskeletal condition which can cause significant pain and lead to complete rupture of the tendon, which often requires surgical repair. Due in part to the large spectrum of tendon pathologies, these disorders continue to be a clinical challenge. Animal models are often used in this field of research as they offer an attractive framework to examine the cascade of processes that occur throughout both tendon pathology and repair. This review discusses the structural, mechanical, and biological changes that occur throughout tendon pathology in animal models, as well as strategies for the improvement of tendon healing. Cite this article: Bone Joint Res 2014;3:193–202

Cite this article: Bone Joint Res 2023;12(9):598–600.

The surgical community is plagued with a reputation for both failing to engage and to deliver on clinical research. This is in part due to the absence of a strong research culture, however it is also due to a multitude of barriers encountered in clinical research; particularly those involving surgical interventions. ‘Trauma’ amplifies these barriers, owing to the unplanned nature of care, unpredictable work patterns, the emergent nature of treatment and complexities in the consent process. This review discusses the barriers to clinical research in surgery, with a particular emphasis on trauma. It considers how barriers may be overcome, with the aim to facilitate future successful clinical research. Cite this article: Bone Joint Res 2014;3:123–9

Aims. A core outcome set for adult, open lower limb fracture has been established consisting of ‘Walking, gait and mobility’, ‘Being able to return to life roles’, ‘Pain or discomfort’, and ‘Quality of life’. This study aims to identify which outcome measurement instruments (OMIs) should be recommended to measure each core outcome. Methods. A systematic review and quality assessment were conducted to identify existing instruments with evidence of good measurement properties in the open lower limb fracture population for each core outcome. Additionally, shortlisting criteria were developed to identify suitable instruments not validated in the target population. Candidate instruments were presented, discussed, and voted on at a consensus meeting of key stakeholders. Results. The Wales Lower Limb Trauma Recovery scale was identified, demonstrating validation evidence in the target population. In addition, ten candidate OMIs met the shortlisting criteria. Six patients, eight healthcare professionals, and 11 research methodologists attended the consensus meeting. Consensus was achieved for the EuroQol five-dimension five-level questionnaire (EQ-5D-5L) and the Lower Extremity Functional Scale (LEFS) to measure ‘Quality of life’ and ‘Walking, gait and mobility’ in future research trials, audit, and clinical assessment, respectively. No instrument met consensus criteria to measure ‘Being able to return to life roles’ and ‘Pain or discomfort’. However, the EQ-5D-5L was found to demonstrate good face validity and could also be used pragmatically to measure these two outcomes, accepting limitations in sensitivity. Conclusion. This study recommends the LEFS and EQ-5D-5L to measure the core outcome set for adult open lower limb fracture. Cite this article: Bone Joint Res 2023;12(6):352–361

Aims. Open lower limb fracture is life-changing, resulting in substantial morbidity and resource demand, while inconsistent outcome-reporting hampers systematic review and meta-analysis. A core outcome set establishes consensus among key stakeholders for the recommendation of a minimum set of outcomes. This study aims to define a core outcome set for adult open lower limb fracture. Methods. Candidate outcomes were identified from a previously published systematic review and a secondary thematic analysis of 25 patient interviews exploring the lived experience of recovery from open lower limb fracture. Outcomes were categorized and sequentially refined using healthcare professional and patient structured discussion groups. Consensus methods included a multi-stakeholder two-round online Delphi survey and a consensus meeting attended by a purposive sample of stakeholders, facilitated discussion, and voting using a nominal group technique. Results. Thematic analysis and systematic review identified 121 unique outcomes, reduced to 68 outcomes following structured discussion groups. Outcomes were presented to 136 participants who completed a two-round online Delphi survey. The Delphi survey resulted in 11 outcomes identified as consensus ‘in’ only. All outcomes were discussed at a consensus meeting attended by 15 patients, 14 healthcare professionals, 11 researchers, and one patient-carer. Consensus was achieved for a four-core outcome set: ‘Walking, gait and mobility’, ‘Being able to return to life roles’, ‘Pain or discomfort’, and ‘Quality of life’. Conclusion. This study used robust consensus methods to establish a core outcome set that should be measured in all future research studies and audits of clinical practice without precluding the measurement of additional outcomes. Cite this article: Bone Joint Res 2023;12(4):294–305

Aims. After a few passages of in vitro culture, primary human articular chondrocytes undergo senescence and loss of their phenotype. Most of the available chondrocyte cell lines have been obtained from cartilage tissues different from diarthrodial joints, and their utility for osteoarthritis (OA) research is reduced. Thus, the goal of this research was the development of immortalized chondrocyte cell lines proceeded from the articular cartilage of patients with and without OA. Methods. Using telomerase reverse transcriptase (hTERT) and SV40 large T antigen (SV40LT), we transduced primary OA articular chondrocytes. Proliferative capacity, degree of senescence, and chondrocyte surface antigen expression in transduced chondrocytes were evaluated. In addition, the capacity of transduced chondrocytes to synthesize a tissue similar to cartilage and to respond to interleukin (IL)-1β was assessed. Results. Coexpression of both transgenes (SV40 and hTERT) were observed in the nuclei of transduced chondrocytes. Generated chondrocyte cell lines showed a high proliferation capacity and less than 2% of senescent cells. These cell lines were able to form 3D aggregates analogous to those generated by primary articular chondrocytes, but were unsuccessful in synthesizing cartilage-like tissue when seeded on type I collagen sponges. However, generated chondrocyte cell lines maintained the potential to respond to IL-1β stimulation. Conclusion. Through SV40LT and hTERT transduction, we successfully immortalized chondrocytes. These immortalized chondrocytes were able to overcome senescence in vitro, but were incapable of synthesizing cartilage-like tissue under the experimental conditions. Nonetheless, these chondrocyte cell lines could be advantageous for OA investigation since, similarly to primary articular chondrocytes, they showed capacity to upregulate inflammatory mediators in response to the IL-1β cytokine. Cite this article: Bone Joint Res 2023;12(1):46–57

Aims. Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters. Methods. We used the PRISMA extension for scoping reviews for this literature search in three databases. After screening, 16 studies were included for the final analysis. Results. The studies assessed different hip conditions like labrum status, the biomechanical effect of the cam, femoral version, acetabular coverage, and the effect of rim trimming. The testing and loading conditions were also quite diverse, and this disparity limits direct comparisons between the different researches. With normal anatomy the mean contact pressures ranged from 1.54 to 4.4 MPa, and the average peak contact pressures ranged from 2 to 9.3 MPa. Labral tear or resection showed an increase in contact pressures that diminished after repair or reconstruction of the labrum. Complete cam resection also decreased the contact pressure, and acetabular rim resection of 6 mm increased the contact pressure at the acetabular base. Conclusion. To date there is no standardized methodology to access hip contact biomechanics in hip arthroscopy, or with the preservation of the periarticular soft-tissues. A tendency towards improved biomechanics (lower contact pressures) was seen with labral repair and reconstruction techniques as well as with cam correction. Cite this article: Bone Joint Res 2023;12(12):712–721

Aims. To evaluate inducing osteoarthritis (OA) by surgical destabilization of the medial meniscus (DMM) in mice with and without a stereomicroscope. Methods. Based on sample size calculation, 70 male C57BL/6 mice were randomly assigned to three surgery groups: DMM aided by a stereomicroscope; DMM by naked eye; or sham surgery. The group information was blinded to researchers. Mice underwent static weightbearing, von Frey test, and gait analysis at two-week intervals from eight to 16 weeks after surgery. Histological grade of OA was determined with the Osteoarthritis Research Society International (OARSI) scoring system. Results. Surgical DMM with or without stereomicroscope led to decrease in the mean of weightbearing percentages (-20.64% vs -21.44%, p = 0.792) and paw withdrawal response thresholds (-21.35% vs -24.65%, p = 0.327) of the hind limbs. However, the coefficient of variation (CV) of weight-bearing percentages and paw withdrawal response thresholds in naked-eye group were significantly greater than that in the microscope group (19.82% vs 6.94%, p < 0.001; 21.85% vs 9.86%, p < 0.001). The gait analysis showed a similar pattern. Cartilage degeneration was observed in both DMM-surgery groups, evidenced by increased OARSI scores (summed score: 11.23 vs 11.43, p = 0.842), but the microscope group showed less variation in OARSI score than the naked-eye group (CV: 21.03% vs 32.44%; p = 0.032). Conclusion. Although surgical DMM aided by stereomicroscope is technically difficult, it produces a relatively more homogeneous OA model in terms of the discrete degree of pain behaviours and histopathological grading when compared with surgical DMM without stereomicroscope. Cite this article: Bone Joint Res 2022;11(8):518–527

Research into COVID-19 has been rapid in response to the dynamic global situation, which has resulted in heterogeneity of methodology and the communication of information. Adherence to reporting standards would improve the quality of evidence presented in future studies, and may ensure that findings could be interpreted in the context of the wider literature. The COVID-19 pandemic remains a dynamic situation, requiring continued assessment of the disease incidence and monitoring for the emergence of viral variants and their transmissibility, virulence, and susceptibility to vaccine-induced immunity. More work is needed to assess the long-term impact of COVID-19 infection on patients who sustain a hip fracture. The International Multicentre Project Auditing COVID-19 in Trauma & Orthopaedics (IMPACT) formed the largest multicentre collaborative audit conducted in orthopaedics in order to provide an emergency response to a global pandemic, but this was in the context of many vital established audit services being disrupted at an early stage, and it is crucial that these resources are protected during future health crises. Rapid data-sharing between regions should be developed, with wider adoption of the revised 2022 Fragility Fracture Network Minimum Common Data Set for Hip Fracture Audit, and a pragmatic approach to information governance processes in order to facilitate cooperation and meta-audit. This editorial aims to: 1) identify issues related to COVID-19 that require further research; 2) suggest reporting standards for studies of COVID-19 and other communicable diseases; 3) consider the requirement of new risk scores for hip fracture patients; and 4) present the lessons learned from IMPACT in order to inform future collaborative studies. Cite this article: Bone Joint Res 2022;11(6):342–345

The use of artificial intelligence (AI) is rapidly growing across many domains, of which the medical field is no exception. AI is an umbrella term defining the practical application of algorithms to generate useful output, without the need of human cognition. Owing to the expanding volume of patient information collected, known as ‘big data’, AI is showing promise as a useful tool in healthcare research and across all aspects of patient care pathways. Practical applications in orthopaedic surgery include: diagnostics, such as fracture recognition and tumour detection; predictive models of clinical and patient-reported outcome measures, such as calculating mortality rates and length of hospital stay; and real-time rehabilitation monitoring and surgical training. However, clinicians should remain cognizant of AI’s limitations, as the development of robust reporting and validation frameworks is of paramount importance to prevent avoidable errors and biases. The aim of this review article is to provide a comprehensive understanding of AI and its subfields, as well as to delineate its existing clinical applications in trauma and orthopaedic surgery. Furthermore, this narrative review expands upon the limitations of AI and future direction. Cite this article: Bone Joint Res 2023;12(7):447–454

Osteoarthritis (OA) is mainly caused by ageing, strain, trauma, and congenital joint abnormalities, resulting in articular cartilage degeneration. During the pathogenesis of OA, the changes in subchondral bone (SB) are not only secondary manifestations of OA, but also an active part of the disease, and are closely associated with the severity of OA. In different stages of OA, there were microstructural changes in SB. Osteocytes, osteoblasts, and osteoclasts in SB are important in the pathogenesis of OA. The signal transduction mechanism in SB is necessary to maintain the balance of a stable phenotype, extracellular matrix (ECM) synthesis, and bone remodelling between articular cartilage and SB. An imbalance in signal transduction can lead to reduced cartilage quality and SB thickening, which leads to the progression of OA. By understanding changes in SB in OA, researchers are exploring drugs that can regulate these changes, which will help to provide new ideas for the treatment of OA. Cite this article: Bone Joint Res 2023;12(9):536–545

Aims. Biofilm-related infection is a major complication that occurs in orthopaedic surgery. Various treatments are available but efficacy to eradicate infections varies significantly. A systematic review was performed to evaluate therapeutic interventions combating biofilm-related infections on in vivo animal models. Methods. Literature research was performed on PubMed and Embase databases. Keywords used for search criteria were “bone AND biofilm”. Information on the species of the animal model, bacterial strain, evaluation of biofilm and bone infection, complications, key findings on observations, prevention, and treatment of biofilm were extracted. Results. A total of 43 studies were included. Animal models used included fracture-related infections (ten studies), periprosthetic joint infections (five studies), spinal infections (three studies), other implant-associated infections, and osteomyelitis. The most common bacteria were Staphylococcus species. Biofilm was most often observed with scanning electron microscopy. The natural history of biofilm revealed that the process of bacteria attachment, proliferation, maturation, and dispersal would take 14 days. For systemic mono-antibiotic therapy, only two of six studies using vancomycin reported significant biofilm reduction, and none reported eradication. Ten studies showed that combined systemic and topical antibiotics are needed to achieve higher biofilm reduction or eradication, and the effect is decreased with delayed treatment. Overall, 13 studies showed promising therapeutic potential with surface coating and antibiotic loading techniques. Conclusion. Combined topical and systemic application of antimicrobial agents effectively reduces biofilm at early stages. Future studies with sustained release of antimicrobial and biofilm-dispersing agents tailored to specific pathogens are warranted to achieve biofilm eradication. Cite this article: Bone Joint Res 2022;11(10):700–714

Aims. Therapeutic agents that prevent chondrocyte loss, extracellular matrix (ECM) degradation, and osteoarthritis (OA) progression are required. The expression level of epidermal growth factor (EGF)-like repeats and discoidin I-like domains-containing protein 3 (EDIL3) in damaged human cartilage is significantly higher than in undamaged cartilage. However, the effect of EDIL3 on cartilage is still unknown. Methods. We used human cartilage plugs (ex vivo) and mice with spontaneous OA (in vivo) to explore whether EDIL3 has a chondroprotective effect by altering OA-related indicators. Results. EDIL3 protein prevented chondrocyte clustering and maintained chondrocyte number and SOX9 expression in the human cartilage plug. Administration of EDIL3 protein prevented OA progression in STR/ort mice by maintaining the number of chondrocytes in the hyaline cartilage and the number of matrix-producing chondrocytes (MPCs). It reduced the degradation of aggrecan, the expression of matrix metalloproteinase (MMP)-13, the Osteoarthritis Research Society International (OARSI) score, and bone remodelling. It increased the porosity of the subchondral bone plate. Administration of an EDIL3 antibody increased the number of matrix-non-producing chondrocytes (MNCs) in cartilage and exacerbated the serum concentrations of OA-related pro-inflammatory cytokines, including monocyte chemotactic protein-3 (MCP-3), RANTES, interleukin (IL)-17A, IL-22, and GROα. Administration of β1 and β3 integrin agonists (CD98 protein) increased the expression of SOX9 in OA mice. Hence, EDIL3 might activate β1 and β3 integrins for chondroprotection. EDIL3 may also protect cartilage by attenuating the expression of IL-1β-enhanced phosphokinase proteins in chondrocytes, especially glycogen synthase kinase 3 alpha/beta (GSK-3α/β) and phospholipase C gamma 1 (PLC-γ1). Conclusion. EDIL3 has a role in maintaining the cartilage ECM and inhibiting the development of OA, making it a potential therapeutic drug for OA. Cite this article: Bone Joint Res 2023;12(12):734–746

Aims. Pigment epithelium-derived factor (PEDF) is known to induce several types of tissue regeneration by activating tissue-specific stem cells. Here, we investigated the therapeutic potential of PEDF 29-mer peptide in the damaged articular cartilage (AC) in rat osteoarthritis (OA). Methods. Mesenchymal stem/stromal cells (MSCs) were isolated from rat bone marrow (BM) and used to evaluate the impact of 29-mer on chondrogenic differentiation of BM-MSCs in culture. Knee OA was induced in rats by a single intra-articular injection of monosodium iodoacetate (MIA) in the right knees (set to day 0). The 29-mer dissolved in 5% hyaluronic acid (HA) was intra-articularly injected into right knees at day 8 and 12 after MIA injection. Subsequently, the therapeutic effect of the 29-mer/HA on OA was evaluated by the Osteoarthritis Research Society International (OARSI) histopathological scoring system and changes in hind paw weight distribution, respectively. The regeneration of chondrocytes in damaged AC was detected by dual-immunostaining of 5-bromo-2'-deoxyuridine (BrdU) and chondrogenic markers. Results. The 29-mer promoted expansion and chondrogenic differentiation of BM-MSCs cultured in different defined media. MIA injection caused chondrocyte death throughout the AC, with cartilage degeneration thereafter. The 29-mer/HA treatment induced extensive chondrocyte regeneration in the damaged AC and suppressed MIA-induced synovitis, accompanied by the recovery of cartilage matrix. Pharmacological inhibitors of PEDF receptor (PEDFR) and signal transducer and activator of transcription 3 (STAT3) signalling substantially blocked the chondrogenic promoting activity of 29-mer on the cultured BM-MSCs and injured AC. Conclusion. The 29-mer/HA formulation effectively induces chondrocyte regeneration and formation of cartilage matrix in the damaged AC. Cite this article: Bone Joint Res 2024;13(4):137–148

Aims. Osteoporosis (OP) is a metabolic bone disease, characterized by a decrease in bone mineral density (BMD). However, the research of regulatory variants has been limited for BMD. In this study, we aimed to explore novel regulatory genetic variants associated with BMD. Methods. We conducted an integrative analysis of BMD genome-wide association study (GWAS) and regulatory single nucleotide polymorphism (rSNP) annotation information. Firstly, the discovery GWAS dataset and replication GWAS dataset were integrated with rSNP annotation database to obtain BMD associated SNP regulatory elements and SNP regulatory element-target gene (E-G) pairs, respectively. Then, the common genes were further subjected to HumanNet v2 to explore the biological effects. Results. Through discovery and replication integrative analysis for BMD GWAS and rSNP annotation database, we identified 36 common BMD-associated genes for BMD irrespective of regulatory elements, such as FAM3C (p. discovery GWAS. = 1.21 × 10. -25. , p. replication GWAS. = 1.80 × 10. -12. ), CCDC170 (p. discovery GWAS. = 1.23 × 10. -11. , p. replication GWAS. = 3.22 × 10. -9. ), and SOX6 (p. discovery GWAS. = 4.41 × 10. -15. , p. replication GWAS. = 6.57 × 10. -14. ). Then, for the 36 common target genes, multiple gene ontology (GO) terms were detected for BMD such as positive regulation of cartilage development (p = 9.27 × 10. -3. ) and positive regulation of chondrocyte differentiation (p = 9.27 × 10. -3. ). Conclusion. We explored the potential roles of rSNP in the genetic mechanisms of BMD and identified multiple candidate genes. Our study results support the implication of regulatory genetic variants in the development of OP. Cite this article: Bone Joint Res 2023;12(2):147–154

Aims. An objective technological solution for tracking adherence to at-home shoulder physiotherapy is important for improving patient engagement and rehabilitation outcomes, but remains a significant challenge. The aim of this research was to evaluate performance of machine-learning (ML) methodologies for detecting and classifying inertial data collected during in-clinic and at-home shoulder physiotherapy exercise. Methods. A smartwatch was used to collect inertial data from 42 patients performing shoulder physiotherapy exercises for rotator cuff injuries in both in-clinic and at-home settings. A two-stage ML approach was used to detect out-of-distribution (OOD) data (to remove non-exercise data) and subsequently for classification of exercises. We evaluated the performance impact of grouping exercises by motion type, inclusion of non-exercise data for algorithm training, and a patient-specific approach to exercise classification. Algorithm performance was evaluated using both in-clinic and at-home data. Results. The patient-specific approach with engineered features achieved the highest in-clinic performance for differentiating physiotherapy exercise from non-exercise activity (area under the receiver operating characteristic (AUROC) = 0.924). Including non-exercise data in algorithm training further improved classifier performance (random forest, AUROC = 0.985). The highest accuracy achieved for classifying individual in-clinic exercises was 0.903, using a patient-specific method with deep neural network model extracted features. Grouping exercises by motion type improved exercise classification. For at-home data, OOD detection yielded similar performance with the non-exercise data in the algorithm training (fully convolutional network AUROC = 0.919). Conclusion. Including non-exercise data in algorithm training improves detection of exercises. A patient-specific approach leveraging data from earlier patient-supervised sessions should be considered but is highly dependent on per-patient data quality. Cite this article: Bone Joint Res 2023;12(3):165–177

Aims. This study aimed to evaluate the effectiveness of the induced membrane technique for treating infected bone defects, and to explore the factors that might affect patient outcomes. Methods. A comprehensive search was performed in PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases between 1 January 2000 and 31 October 2021. Studies with a minimum sample size of five patients with infected bone defects treated with the induced membrane technique were included. Factors associated with nonunion, infection recurrence, and additional procedures were identified using logistic regression analysis on individual patient data. Results. After the screening, 44 studies were included with 1,079 patients and 1,083 segments of infected bone defects treated with the induced membrane technique. The mean defect size was 6.8 cm (0.5 to 30). After the index second stage procedure, 85% (797/942) of segments achieved union, and 92% (999/1,083) of segments achieved final healing. The multivariate analysis with data from 296 patients suggested that older age was associated with higher nonunion risk. Patients with external fixation in the second stage had a significantly higher risk of developing nonunion, increasing the need for additional procedures. The autografts harvested from the femur reamer-irrigator-aspirator increased nonunion, infection recurrence, and additional procedure rates. Conclusion. The induced membrane technique is an effective technique for treating infected bone defects. Internal fixation during the second stage might effectively promote bone healing and reduce additional procedures without increasing infection recurrence. Future studies should standardize individual patient data prospectively to facilitate research on the affected patient outcomes. Cite this article: Bone Joint Res 2023;12(9):546–558

Aims. In this investigation, we administered oxidative stress to nucleus pulposus cells (NPCs), recognized DNA-damage-inducible transcript 4 (DDIT4) as a component in intervertebral disc degeneration (IVDD), and devised a hydrogel capable of conveying small interfering RNA (siRNA) to IVDD. Methods. An in vitro model for oxidative stress-induced injury in NPCs was developed to elucidate the mechanisms underlying the upregulation of DDIT4 expression, activation of the reactive oxygen species (ROS)-thioredoxin-interacting protein (TXNIP)-NLRP3 signalling pathway, and nucleus pulposus pyroptosis. Furthermore, the mechanism of action of small interfering DDIT4 (siDDIT4) on NPCs in vitro was validated. A triplex hydrogel named siDDIT4@G5-P-HA was created by adsorbing siDDIT4 onto fifth-generation polyamidoamine (PAMAM) dendrimer using van der Waals interactions, and then coating it with hyaluronic acid (HA). In addition, we established a rat puncture IVDD model to decipher the hydrogel’s mechanism in IVDD. Results. A correlation between DDIT4 expression levels and disc degeneration was shown with human nucleus pulposus and needle-punctured rat disc specimens. We confirmed that DDIT4 was responsible for activating the ROS-TXNIP-NLRP3 axis during oxidative stress-induced pyroptosis in rat nucleus pulposus in vitro. Mitochondria were damaged during oxidative stress, and DDIT4 contributed to mitochondrial damage and ROS production. In addition, siDDIT4@G5-P-HA hydrogels showed good delivery activity of siDDIT4 to NPCs. In vitro studies illustrated the potential of the siDDIT4@G5-P-HA hydrogel for alleviating IVDD in rats. Conclusion. DDIT4 is a key player in mediating pyroptosis and IVDD in NPCs through the ROS-TXNIP-NLRP3 axis. Additionally, siDDIT4@G5-P-HA hydrogel has been found to relieve IVDD in rats. Our research offers an innovative treatment option for IVDD. Cite this article: Bone Joint Res 2024;13(5):247–260

Aims. This study examined whether systemic administration of melatonin would have different effects on osseointegration in ovariectomized (OVX) rats, depending on whether this was administered during the day or night. Methods. In this study, a titanium rod was implanted in the medullary cavity of one femoral metaphysis in OVX rats, and then the rats were randomly divided into four groups: Sham group (Sham, n = 10), OVX rat group (OVX, n = 10), melatonin day treatment group (OVX + MD, n = 10), and melatonin night treatment group (OVX + MN, n = 10). The OVX + MD and OVX + MN rats were treated with 30 mg/kg/day melatonin at 9 am and 9 pm, respectively, for 12 weeks. At the end of the research, the rats were killed to obtain bilateral femora and blood samples for evaluation. Results. Micro-CT and histological evaluation showed that the bone microscopic parameters of femoral metaphysis trabecular bone and bone tissue around the titanium rod in the OVX + MD group demonstrated higher bone mineral density, bone volume fraction, trabecular number, connective density, trabecular thickness, and lower trabecular speculation (p = 0.004) than the OVX + MN group. Moreover, the biomechanical parameters of the OVX + MD group showed higher pull-out test and three-point bending test values, including fixation strength, interface stiffness, energy to failure, energy at break, ultimate load, and elastic modulus (p = 0.012) than the OVX + MN group. In addition, the bone metabolism index and oxidative stress indicators of the OVX + MD group show lower values of Type I collagen cross-linked C-telopeptide, procollagen type 1 N propeptide, and malondialdehyde (p = 0.013), and higher values of TAC and SOD (p = 0.002) compared with the OVX + MN group. Conclusion. The results of our study suggest that systemic administration with melatonin at 9 am may improve the initial osseointegration of titanium rods under osteoporotic conditions more effectively than administration at 9 pm. Cite this article: Bone Joint Res 2022;11(11):751–762

Aims. Dupuytren’s contracture is characterized by increased fibrosis of the palmar aponeurosis, with eventual replacement of the surrounding fatty tissue with palmar fascial fibromatosis. We hypothesized that adipocytokines produced by adipose tissue in contact with the palmar aponeurosis might promote fibrosis of the palmar aponeurosis. Methods. We compared the expression of the adipocytokines adiponectin and leptin in the adipose tissue surrounding the palmar aponeurosis of male patients with Dupuytren’s contracture, and of male patients with carpal tunnel syndrome (CTS) as the control group. We also examined the effects of adiponectin on fibrosis-related genes and proteins expressed by fibroblasts in the palmar aponeurosis of patients with Dupuytren’s contracture. Results. Adiponectin expression in the adipose tissue surrounding the palmar aponeurosis was significantly lower in patients with Dupuytren’s contracture than in those with CTS. The expression of fibrosis-related genes and proteins, such as types 1 and 3 collagen and α-smooth muscle actin, was suppressed in a concentration-dependent manner by adding AdipoRon, an adiponectin receptor agonist. The expression of fibrosis-related genes and proteins was also suppressed by AdipoRon in the in vitro model of Dupuytren’s contracture created by adding TGF-β to normal fibroblasts collected from patients with CTS. Conclusion. Fibrosis of the palmar aponeurosis in Dupuytren’s contracture in males may be associated with adiponectin expression in the adipose tissue surrounding the palmar aponeurosis. Although fibroblasts within the palmar aponeurosis are often the focus of attention when elucidating the pathogenesis of Dupuytren’s contracture, adiponectin expression in adipose tissues warrants closer attention in future research. Cite this article: Bone Joint Res 2023;12(8):486–493

Osteoarthritis (OA) is a degenerative disease resulting from progressive joint destruction caused by many factors. Its pathogenesis is complex and has not been elucidated to date. Advanced glycation end products (AGEs) are a series of irreversible and stable macromolecular complexes formed by reducing sugar with protein, lipid, and nucleic acid through a non-enzymatic glycosylation reaction (Maillard reaction). They are an important indicator of the degree of ageing. Currently, it is considered that AGEs accumulation in vivo is a molecular basis of age-induced OA, and AGEs production and accumulation in vivo is one of the important reasons for the induction and acceleration of the pathological changes of OA. In recent years, it has been found that AGEs are involved in a variety of pathological processes of OA, including extracellular matrix degradation, chondrocyte apoptosis, and autophagy. Clearly, AGEs play an important role in regulating the expression of OA-related genes and maintaining the chondrocyte phenotype and the stability of the intra-articular environment. This article reviews the latest research results of AGEs in a variety of pathological processes of OA, to provide a new direction for the study of OA pathogenesis and a new target for prevention and treatment. Cite this article: Bone Joint Res 2022;11(5):292–300

Aims. The association of auraptene (AUR), a 7-geranyloxycoumarin, on osteoporosis and its potential pathway was predicted by network pharmacology and confirmed in experimental osteoporotic mice. Methods. The network of AUR was constructed and a potential pathway predicted by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) terms enrichment. Female ovariectomized (OVX) Institute of Cancer Research mice were intraperitoneally injected with 0.01, 0.1, and 1 mM AUR for four weeks. The bone mineral density (BMD) level was measured by dual-energy X-ray absorptiometry. The bone microstructure was determined by histomorphological changes in the femora. In addition, biochemical analysis of the serum and assessment of the messenger RNA (mRNA) levels of osteoclastic markers were performed. Results. In total, 65.93% of the genes of the AUR network matched with osteoporosis-related genes. Osteoclast differentiation was predicted to be a potential pathway of AUR in osteoporosis. Based on the network pharmacology, the BMD and bone mineral content levels were significantly (p < 0.05) increased in the whole body, femur, tibia, and lumbar spine by AUR. AUR normalized the bone microstructure and the serum alkaline phosphatase (ALP), bone-specific alkaline phosphatase (bALP), osteocalcin, and calcium in comparison with the OVX group. In addition, AUR treatment reduced TRAP-positive osteoclasts and receptor activator of nuclear factor kappa-B ligand (RANKL). +. nuclear factor of activated T cells 1 (NFATc1). +. expression in the femoral body. Moreover, the expressions of initiators for osteoclastic resorption and bone matrix degradation were significantly (p < 0.05) regulated by AUR in the lumbar spine of the osteoporotic mice. Conclusion. AUR ameliorated bone loss by downregulating the RANKL/NFATc1 pathway, resulting in improvement of osteoporosis. In conclusion, AUR might be an ameliorative cure that alleviates bone loss in osteoporosis via inhibition of osteoclastic activity. Cite this article: Bone Joint Res 2022;11(5):304–316

Aims. Assessment of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA) is a well-established clinical technique, but it is not available in the acute trauma setting. Thus, it cannot provide a preoperative estimation of BMD to help guide the technique of fracture fixation. Alternative methods that have been suggested for assessing BMD include: 1) cortical measures, such as cortical ratios and combined cortical scores; and 2) aluminium grading systems from preoperative digital radiographs. However, limited research has been performed in this area to validate the different methods. The aim of this study was to investigate the evaluation of BMD from digital radiographs by comparing various methods against DXA scanning. Methods. A total of 54 patients with distal radial fractures were included in the study. Each underwent posteroanterior (PA) and lateral radiographs of the injured wrist with an aluminium step wedge. Overall 27 patients underwent routine DXA scanning of the hip and lumbar spine, with 13 undergoing additional DXA scanning of the uninjured forearm. Analysis of radiographs was performed on ImageJ and Matlab with calculations of cortical measures, cortical indices, combined cortical scores, and aluminium equivalent grading. Results. Cortical measures showed varying correlations with the forearm DXA results (range: Pearson correlation coefficient (r) = 0.343 (p = 0.251) to r = 0.521 (p = 0.068)), with none showing statistically significant correlations. Aluminium equivalent grading showed statistically significant correlations with the forearm DXA of the corresponding region of interest (p < 0.017). Conclusion. Cortical measures, cortical indices, and combined cortical scores did not show a statistically significant correlation to forearm DXA measures. Aluminium-equivalent is an easily applicable method for estimation of BMD from digital radiographs in the preoperative setting. Cite this article: Bone Joint Res 2021;10(12):830–839

Aims. Femoroacetabular impingement (FAI) describes abnormal bony contact of the proximal femur against the acetabulum. The term was first coined in 1999; however what is often overlooked is that descriptions of the morphology have existed in the literature for centuries. The aim of this paper is to delineate its origins and provide further clarity on FAI to shape future research. Methods. A non-systematic search on PubMed was performed using keywords such as “impingement” or “tilt deformity” to find early anatomical descriptions of FAI. Relevant references from these primary studies were then followed up. Results. Although FAI has existed for almost 5,000 years, the anatomical study by Henle in 1855 was the first to describe it in the literature. The relevance of the deformity was not appreciated at the time but this triggered the development of further anatomical studies. Parallel to this, Poland performed the first surgical correction of FAI in 1898 and subsequently, descriptions of similar procedures followed. In 1965, Murray outlined radiological evidence of idiopathic cam-type deformities and highlighted its significance. This led to a renewed focus on FAI and eventually, Ganz et al released their seminal paper that has become the foundation of our current understanding of FAI. Since then, there has been an exponential rise in published literature but finding a consensus, especially in the diagnosis of FAI, has proven to be difficult. Conclusion. Current research on FAI heavily focuses on new data, but old evidence does exist and studying it could be equally as important in clarifying the aetiology and classification of FAI. Cite this article: Bone Joint Res 2020;9(9):572–577

Aims. Osteoarthritis (OA) is prevalent among the elderly and incurable. Intra-articular parathyroid hormone (PTH) ameliorated OA in papain-induced and anterior cruciate ligament transection-induced OA models; therefore, we hypothesized that PTH improved OA in a preclinical age-related OA model. Methods. Guinea pigs aged between six and seven months of age were randomized into control or treatment groups. Three- or four-month-old guinea pigs served as the young control group. The knees were administered 40 μl intra-articular injections of 10 nM PTH or vehicle once a week for three months. Their endurance as determined from time on the treadmill was evaluated before kill. Their tibial plateaus were analyzed using microcalculated tomography (μCT) and histological studies. Results. PTH increased the endurance on the treadmill test, preserved glycosaminoglycans, and reduced Osteoarthritis Research Society International score and chondrocyte apoptosis rate. No difference was observed in the subchondral plate bone density or metaphyseal trabecular bone volume and bone morphogenetic 2 protein staining. Conclusion. Subchondral bone is crucial in the initiation and progression of OA. Although previous studies have shown that subcutaneous PTH alleviates knee OA by improving subchondral and metaphyseal bone mass, we demonstrated that intra-articular PTH injections improved spontaneous OA by directly affecting the cartilage rather than the subchondral or metaphyseal bone in a preclinical age-related OA model. Cite this article: Bone Joint Res 2021;10(8):514–525

Elevated levels of circulating cobalt ions have been linked with a wide range of systemic complications including neurological, endocrine, and cardiovascular symptoms. Case reports of patients with elevated blood cobalt ions have described significant cardiovascular complications including cardiomyopathy. However, correlation between the actual level of circulating cobalt and extent of cardiovascular injury has not previously been performed. This review examines evidence from the literature for a link between elevated blood cobalt levels secondary to metal-on-metal (MoM) hip arthroplasties and cardiomyopathy. Correlation between low, moderate, and high blood cobalt with cardiovascular complications has been considered. Elevated blood cobalt at levels over 250 µg/l have been shown to be a risk factor for developing systemic complications and published case reports document cardiomyopathy, cardiac transplantation, and death in patients with severely elevated blood cobalt ions. However, it is not clear that there is a hard cut-off value and cardiac dysfunction may occur at lower levels. Clinical and laboratory research has found conflicting evidence of cobalt-induced cardiomyopathy in patients with MoM hips. Further work needs to be done to clarify the link between severely elevated blood cobalt ions and cardiomyopathy. Cite this article: Bone Joint Res 2021;10(6):340–347

Bone is one of the most highly adaptive tissues in the body, possessing the capability to alter its morphology and function in response to stimuli in its surrounding environment. The ability of bone to sense and convert external mechanical stimuli into a biochemical response, which ultimately alters the phenotype and function of the cell, is described as mechanotransduction. This review aims to describe the fundamental physiology and biomechanisms that occur to induce osteogenic adaptation of a cell following application of a physical stimulus. Considerable developments have been made in recent years in our understanding of how cells orchestrate this complex interplay of processes, and have become the focus of research in osteogenesis. We will discuss current areas of preclinical and clinical research exploring the harnessing of mechanotransductive properties of cells and applying them therapeutically, both in the context of fracture healing and de novo bone formation in situations such as nonunion. Cite this article: Bone Joint Res 2019;9(1):1–14

Osteoarthritis (OA), one of the most common motor system disorders, is a degenerative disease involving progressive joint destruction caused by a variety of factors. At present, OA has become the fourth most common cause of disability in the world. However, the pathogenesis of OA is complex and has not yet been clarified. Long non-coding RNA (lncRNA) refers to a group of RNAs more than 200 nucleotides in length with limited protein-coding potential, which have a wide range of biological functions including regulating transcriptional patterns and protein activity, as well as binding to form endogenous small interference RNAs (siRNAs) and natural microRNA (miRNA) molecular sponges. In recent years, a large number of lncRNAs have been found to be differentially expressed in a variety of pathological processes of OA, including extracellular matrix (ECM) degradation, synovial inflammation, chondrocyte apoptosis, and angiogenesis. Obviously, lncRNAs play important roles in regulating gene expression, maintaining the phenotype of cartilage and synovial cells, and the stability of the intra-articular environment. This article reviews the results of the latest research into the role of lncRNAs in a variety of pathological processes of OA, in order to provide a new direction for the study of OA pathogenesis and a new target for prevention and treatment. Cite this article: Bone Joint Res 2021;10(2):122–133

Aims. Ageing-related incompetence becomes a major hurdle for the clinical translation of adult stem cells in the treatment of osteoarthritis (OA). This study aims to investigate the effect of stepwise preconditioning on cellular behaviours in human mesenchymal stem cells (hMSCs) from ageing patients, and to verify their therapeutic effect in an OA animal model. Methods. Mesenchymal stem cells (MSCs) were isolated from ageing patients and preconditioned with chondrogenic differentiation medium, followed by normal growth medium. Cellular assays including Bromodeoxyuridine / 5-bromo-2'-deoxyuridine (BrdU), quantitative polymerase chain reaction (q-PCR), β-Gal, Rosette forming, and histological staining were compared in the manipulated human mesenchymal stem cells (hM-MSCs) and their controls. The anterior cruciate ligament transection (ACLT) rabbit models were locally injected with two millions, four millions, or eight millions of hM-MSCs or phosphate-buffered saline (PBS). Osteoarthritis Research Society International (OARSI) scoring was performed to measure the pathological changes in the affected joints after staining. Micro-CT analysis was conducted to determine the microstructural changes in subchondral bone. Results. Stepwise preconditioning approach significantly enhanced the proliferation and chondrogenic potential of ageing hMSCs at early passage. Interestingly, remarkably lower immunogenicity and senescence was also found in hM-MSCs. Data from animal studies showed cartilage damage was retarded and subchondral bone remodelling was prevented by the treatment of preconditioned MSCs. The therapeutic effect depended on the number of cells applied to animals, with the best effect observed when treated with eight millions of hM-MSCs. Conclusion. This study demonstrated a reliable and feasible stepwise preconditioning strategy to improve the safety and efficacy of ageing MSCs for the prevention of OA development. Cite this article: Bone Joint Res 2021;10(1):10–21

Aims. The purpose of our study was to determine whether mesenchymal stem cells (MSCs) are an effective and safe therapeutic agent for the treatment of knee osteoarthritis (OA), owing to their cartilage regeneration potential. Methods. We searched PubMed, Embase, and the Cochrane Library, with keywords including “knee osteoarthritis” and “mesenchymal stem cells”, up to June 2019. We selected randomized controlled trials (RCTs) that explored the use of MSCs to treat knee OA. The visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), adverse events, and the whole-organ MRI score (WORMS) were used as the primary evaluation tools in the studies. Our meta-analysis included a subgroup analysis of cell dose and cell source. Results. Seven trials evaluating 256 patients were included in the meta-analysis. MSC treatment significantly improved the VAS (mean difference (MD), –13.24; 95% confidence intervals (CIs) –23.28 to –3.20, p = 0.010) and WOMAC (MD, –7.22; 95% CI –12.97 to –1.47, p = 0.010). The low-dose group with less than 30 million cells showed lower p-values for both the VAS and WOMAC. Adipose and umbilical cord–derived stem cells also had lower p-values for pain scores than those derived from bone marrow. Conclusion. Overall, MSC-based cell therapy is a relatively safe treatment that holds great potential for OA, evidenced by a positive effect on pain and knee function. Using low-dose (25 million) and adipose-derived stem cells is likely to achieve better results, but further research is needed. Cite this article: Bone Joint Res 2020;9(10):719–728

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The aims of this study were to identify and evaluate the current literature examining the prognostic factors which are associated with failure of total elbow arthroplasty (TEA).

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Mendelian randomization (MR) is considered to overcome the bias of observational studies, but there is no current meta-analysis of MR studies on rheumatoid arthritis (RA). The purpose of this study was to summarize the relationship between potential pathogenic factors and RA risk based on existing MR studies.

Cite this article: Bone Joint Res 2023;12(3):199–201.

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To investigate the effects of senescent osteocytes on bone homeostasis in the progress of age-related osteoporosis and explore the underlying mechanism.

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Osteoarthritis (OA) is the most common chronic pathema of human joints. The pathogenesis is complex, involving physiological and mechanical factors. In previous studies, we found that ferroptosis is intimately related to OA, while the role of Sat1 in chondrocyte ferroptosis and OA, as well as the underlying mechanism, remains unclear.

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Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant (gynura bicolor), has demonstrated anti-inflammatory properties in various diseases. We aimed to explore the chondroprotective effect of DHCA on OA and its potential mechanism.

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In this study, we aimed to visualize the spatial distribution characteristics of femoral head necrosis using a novel measurement method.

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To investigate the efficacy of ethylenediaminetetraacetic acid-normal saline (EDTA-NS) in dispersing biofilms and reducing bacterial infections.

Aims. Cementless acetabular components rely on press-fit fixation for initial stability. In certain cases, initial stability is more difficult to obtain (such as during revision). No current study evaluates how a surgeon’s impaction technique (mallet mass, mallet velocity, and number of strikes) may affect component fixation. This study seeks to answer the following research questions: 1) how does impaction technique affect a) bone strain generation and deterioration (and hence implant stability) and b) seating in different density bones?; and 2) can an impaction technique be recommended to minimize risk of implant loosening while ensuring seating of the acetabular component?. Methods. A custom drop tower was used to simulate surgical strikes seating acetabular components into synthetic bone. Strike velocity and drop mass were varied. Synthetic bone strain was measured using strain gauges and stability was assessed via push-out tests. Polar gap was measured using optical trackers. Results. A phenomenon of strain deterioration was identified if an excessive number of strikes was used to seat a component. This effect was most pronounced in low-density bone at high strike velocities. Polar gap was reduced with increasing strike mass and velocity. Conclusion. A high mallet mass with low strike velocity resulted in satisfactory implant stability and polar gap, while minimizing the risk of losing stability due to over-striking. Extreme caution not to over-strike must be exercised when using high velocity strikes in low-density bone for any mallet mass. Cite this article: Bone Joint Res 2020;9(7):386–393