Virtual reality training to improve complex skills – concerns and remarks:A Letter to the Editor

Background: There has been limited literature on immersive virtual reality (VR) simulation in orthopaedic education. The purpose of this multicenter, blinded, randomized controlled trial was to determine the validity and efficacy of immersive VR training in orthopaedic resident education.Methods: Nineteen senior orthopaedic residents (resident group) and 7 consultant shoulder arthroplasty surgeons (expert group) participated in the trial comparing immersive VR with traditional learning using a technical journal article as a control. The examined task focused on achieving optimal glenoid exposure. Participants completed demographic qu`estionnaires, knowledge tests, and a glenoid exposure on fresh-frozen cadavers while being examined by blinded shoulder arthroplasty surgeons. Training superiority was determined by the outcome measures of the Objective Structured Assessment of Technical Skills (OSATS) score, a developed laboratory metric, verbal answers, and time to task completion.Results: Immersive VR had greater realism and was superior in teaching glenoid exposure than the control (p = 0.01). The expert group outperformed the resident group on knowledge testing (p = 0.04). The immersive VR group completed the learning activity and knowledge tests significantly faster (p < 0.001) at a mean time (and standard deviation) of 11 +/- 3 minutes than the control group at 20 +/- 4 minutes, performing 3 to 5 VR repeats for a reduction in learning time of 570%. The immersive VR group completed the glenoid exposure significantly faster ( p = 0.04) at a mean time of 14 +/- 7 minutes than the control group at 21 +/- 6 minutes, with superior OSATS instrument handling scores (p = 0.03). The immersive VR group scored equivalently in surprise verbal scores (p = 0.85) and written knowledge scores (p = 1.0).Conclusions: Immersive VR demonstrated substantially improved translational technical and nontechnical skills acquisition over traditional learning in senior orthopaedic residents. Additionally, the results demonstrate the face, content, construct, and transfer validity for immersive VR

Early changes in the extracellular matrix of the degenerating intervertebral disc, assessed by Fourier transform infrared imaging.

Mechanical overloading induces a degenerative cell response in the intervertebral disc. However, early changes in the extracellular matrix (ECM) are challenging to assess with conventional techniques. Fourier Transform Infrared (FTIR) imaging allows visualization and quantification of the ECM. We aim to identify markers for disc degeneration and apply these to investigate early degenerative changes due to overloading and katabolic cell activity. Three experiments were conducted; Exp 1.: In vivo, lumbar spines of seven goats were operated: one disc was injected with chondroitinase ABC (mild degeneration) and compared to the adjacent disc (control) after 24 weeks. Exp 2a: Ex vivo, caprine discs received physiological loading (n=10) or overloading (n=10) in a bioreactor. Exp 2b: Cell activity was diminished prior to testing by freeze-thaw cycles, 18 discs were then tested as in Exp 2a. In all experiments, FTIR images (spectral region: 1000-1300 cm ) of mid-sagittal slices were analyzed using multivariate curve resolution. In vivo, FTIR was more sensitive than biochemical and histological analysis in identifying reduced proteoglycan content (p=0.046) and increased collagen content in degenerated discs (p<0.01). Notably, FTIR analysis additionally showed disorganization of the ECM, indicated by increased collagen entropy (p=0.011). Ex vivo, the proteoglycan/collagen ratio decreased due to overloading (p=0.047) and collagen entropy increased (p=0.047). Cell activity affected collagen content only (p=0.044). FTIR imaging allows a more detailed investigation of early disc degeneration than traditional measures. Changes due to mild overloading could be assessed and quantified. Matrix remodeling is the first detectable step towards intervertebral disc degeneration. [Abstract copyright: Copyright © 2018. Published by Elsevier Ltd.

Incidence, prevalence and nature of injuries in padel : a systematic review

DATA AVAILABILITY STATEMENT : Data are available on reasonable request.OBJECTIVE : It is unclear what the incidence, prevalence and nature of injuries are that can occur during playing padel. This study aimed to systematically review the incidence, prevalence and nature of injuries in padel. METHOD : A literature search was performed up to December 2022 through MEDLINE Ovid, PubMed, Cochrane Library, SportsDiscus and CINAHL. Following database search, article retrieval and title and abstract screening, articles were assessed for eligibility against predefined criteria. Studies were assessed for methodological quality. Data on injuries’ prevalence, incidence and nature of injuries were extracted, analysed and described in a descriptive statistical manner which did not include a pooling strategy as part of a formal meta-analysis. RESULTS : Eight studies with 2022 participants were included (range of mean age: 31–57). The incidence rate was 3 injuries per 1000 hours of padel training and 8 injuries per 1000 matches of padel practice. The overall prevalence range was 40%–95%. The elbow was the most common anatomical site of injury, followed by the knee, shoulder and lower back. Tendinous and muscular injuries were the most reported injury types. CONCLUSION : Injuries are common among padel players, with an incidence rate of 3 per 1000 hours of padel training and 8 per 1000 matches of padel practice—as based on limited literature. The overall prevalence range was 40%–95%. The elbow was the most frequently reported anatomical region concerning location injury distribution, and injuries were mainly of tendinous or muscular origin.https://bmjopensem.bmj.comhj2023Sports Medicin

Injectable biomaterial induces regeneration of the intervertebral disc in a caprine loaded disc culture model †

Back pain is the leading cause of disability with half of cases attributed to intervertebral disc (IVD) degeneration, yet currently no therapies target this cause. We previously reported an ex vivo caprine loaded disc culture system (LDCS) that accurately represents the cellular phenotype and biomechanical environment of human IVD degeneration. Here, the efficacy of an injectable hydrogel system (LAPONITE® crosslinked pNIPAM-co-DMAc, (NPgel)) to halt or reverse the catabolic processes of IVD degeneration was investigated within the LDCS. Following enzymatic induction of degeneration using 1 mg mL−1 collagenase and 2 U mL−1 chondroitinase ABC within the LDCS for 7 days, IVDs were injected with NPgel alone or with encapsulated human bone marrow progenitor cells (BMPCs). Un-injected caprine discs served as degenerate controls. IVDs were cultured for a further 21 days within the LDCS. Tissues were then processed for histology and immunohistochemistry. No extrusion of NPgel was observed during culture. A significant decrease in histological grade of degeneration was seen in both IVDs injected with NPgel alone and NPgel seeded with BMPCs, compared to un-injected controls. Fissures within degenerate tissue were filled by NPgel and there was evidence of native cell migration into injected NPgel. The expression of healthy NP matrix markers (collagen type II and aggrecan) was increased, whereas the expression of catabolic proteins (MMP3, ADAMTS4, IL-1β and IL-8) was decreased in NPgel (±BMPCs) injected discs, compared to degenerate controls. This demonstrates that NPgel promotes new matrix production at the same time as halting the degenerative cascade within a physiologically relevant testing platform. This highlights the potential of NPgel as a future therapy for IVD degeneration

Minimally Invasive Micro-Indentation: mapping tissue mechanics at the tip of an 18G needle

Experiments regarding the mechanical properties of soft tissues mostly rely on data collected on specimens that are extracted from their native environment. During the extraction and in the time period between the extraction and the completion of the measurements, however, the specimen may undergo structural changes which could generate unwanted artifacts. To further investigate the role of mechanics in physiology and possibly use it in clinical practices, it is thus of paramount importance to develop instruments that could measure the viscoelastic response of a tissue without necessarily excising it. Tantalized by this opportunity, we have designed a minimally invasive micro-indenter that is able to probe the mechanical response of soft tissues, in situ, via an 18G needle. Here, we discuss its working principle and validate its usability by mapping the viscoelastic properties of a complex, confined sample, namely, the nucleus pulposus of the intervertebral disc. Our findings show that the mechanical properties of a biological tissue in its local environment may be indeed different than those that one would measure after excision, and thus confirm that, to better understand the role of mechanics in life sciences, one should always perform minimally invasive measurements like those that we have here introduced

Stiffening of the nucleus pulposus upon axial loading of the intervertebral disc: An experimental in situ study

Mechanical loading is inherently related to the function and degeneration of the intervertebral disc. We present a series of experiments aimed at measuring the effect of a loading/unloading cycle of the intervertebral disc on the mechanical properties of the nucleus pulposus. The study relies on our new minimally invasive microindenter, which allows us to quantify the storage and loss moduli of the nucleus pulposus by inserting an optomechanical probe in an intact (resected) intervertebral disk through the annulus fibrosis via a small needle. Our results indicate that, under the influence of compressive loading, the nucleus pulposus exhibits a more solid-like behavior

Erratum:Publisher Correction: Minimally Invasive Micro-Indentation: mapping tissue mechanics at the tip of an 18G needle (Scientific reports (2017) 7 1 (11364))

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper

The preferred technique for knee synovium biopsy and synovial fluid arthrocentesis

For knee osteoarthritis and related conditions, analysis of biomarkers hold promise to improve early diagnosis and/or offer patient-specific treatment. To compare biomarker analyses, reliable, high-quality biopsies are needed. The aim of this work is to summarize the literature on the current best practices of biopsy of the synovium and synovial fluid arthrocentesis. Therefore, PubMed, Embase and Web of Science were systematically searched for articles that applied, demonstrated, or evaluated synovial biopsies or arthrocentesis. Expert recommendations and applications were summarized, and evidence for superiority of techniques was evaluated. Thirty-one studies were identified for inclusion. For arthrocentesis, the superolateral approach in a supine position, with a 0°-30° knee flexion was generally recommended. 18-gage needles, mechanical compression and ultrasound-guidance were found to give superior results. For blind and image-guided synovial biopsy techniques, superolateral and infrapatellar approaches were recommended. Single-handed tools were preconized, including Parker-Pearson needles and forceps. Sample quantity ranged approximately from 2 to 20. Suggestions were compiled for arthrocentesis regarding approach portal and patient position. Further evidence regarding needle size, ultrasound-guidance and mechanical compression were found. More comparative studies are needed before evidence-based protocols can be developed

The preferred technique for knee synovium biopsy and synovial fluid arthrocentesis

For knee osteoarthritis and related conditions, analysis of biomarkers hold promise to improve early diagnosis and/or offer patient-specific treatment. To compare biomarker analyses, reliable, high-quality biopsies are needed. The aim of this work is to summarize the literature on the current best practices of biopsy of the synovium and synovial fluid arthrocentesis. Therefore, PubMed, Embase and Web of Science were systematically searched for articles that applied, demonstrated, or evaluated synovial biopsies or arthrocentesis. Expert recommendations and applications were summarized, and evidence for superiority of techniques was evaluated. Thirty-one studies were identified for inclusion. For arthrocentesis, the superolateral approach in a supine position, with a 0°-30° knee flexion was generally recommended. 18-gage needles, mechanical compression and ultrasound-guidance were found to give superior results. For blind and image-guided synovial biopsy techniques, superolateral and infrapatellar approaches were recommended. Single-handed tools were preconized, including Parker-Pearson needles and forceps. Sample quantity ranged approximately from 2 to 20. Suggestions were compiled for arthrocentesis regarding approach portal and patient position. Further evidence regarding needle size, ultrasound-guidance and mechanical compression were found. More comparative studies are needed before evidence-based protocols can be developed

Are axial intervertebral disc biomechanics determined by osmosis?

The intervertebral disc faces high compressive forces during daily activities. Axial compression induces creeping fluid loss and reduction in disc height. With degeneration, disc fluids and height are progressively lost, altering biomechanics. It is assumed that this reduction of fluids is caused by a decline of osmolality within the disc due to proteoglycan depletion. Here we investigate the isolated effect of a reduction in osmosis on the biomechanical properties of the intervertebral disc. Continuous diurnal loading was applied to healthy caprine intervertebral discs in a loaded disc culture system for a total of 6days. We increased testing bath osmolality with two doses of polyethylene-glycol (PEG), thereby reducing the osmotic gradient between the disc and the surrounding fluid. This way we could study the isolated effect of reduced osmosis on axial creep, without damaging the disc. We evaluated: daily creep and recovery, recovery time-constants and compressive stiffness. Additionally, we investigated water content. There was a strong dose-dependent effect of PEG concentration on water content and axial creep behaviour: disc height, amplitude and rate of creep and recovery were all significantly reduced. Axial compressive stiffness of the disc was not affected. Reduction of water content and amplitude of creep and recovery showed similarity to degenerative disc biomechanics. However, the time-constants increased, indicating that the hydraulic permeability was reduced, in contrast to what happens with degeneration. This suggests that besides the osmotic gradient, the permeability of the tissues determines healthy intervertebral disc biomechanic