Biodegradable materials, including natural and synthetic polymers and hydrolyzable metals, constitute the main components of temporary, implantable medical devices. Besides the intrinsic properties ...of the materials, the most critical factor determining the successful clinical outcome of implantable and degradable devices is the host response, particularly the immune response, which largely depends on the material features and degradation mechanisms. In this Review, we first survey the state of the art in terms of materials options for use in biodegradable medical devices, focusing on degradation mechanisms and their control. In particular, we highlight silk, which is emerging as an important polymer, owing to its mechanical robustness, bioactive component sequestration, degradability without problematic metabolic products and biocompatibility. We then discuss the host response to these biodegradable materials in terms of dynamic tissue–implant interfaces. Next, we examine the clinical translation of three leading biodegradable material systems — natural and synthetic biodegradable polymers and biodegradable metals — and the related challenges in the context of orthopaedic fixation devices, cardiovascular stents and biodegradable electronic devices. Looking to the future, we propose updated material design strategies to improve the clinical outcomes for these biodegradable medical devices.Clinical outcomes with implantable and degradable devices largely depend on host response. This Review surveys material options and degradation mechanisms relevant to host responses to biodegradable devices, examines clinical translation of leading biodegradable materials and proposes updated material-design strategies to improve device performance.
Trabecular bone is a highly porous, heterogeneous, and anisotropic material which can be found at the epiphyses of long bones and in the vertebral bodies. Studying the mechanical properties of ...trabecular bone is important, since trabecular bone is the main load bearing bone in vertebral bodies and also transfers the load from joints to the compact bone of the cortex of long bones. This review article highlights the high dependency of the mechanical properties of trabecular bone on species, age, anatomic site, loading direction, and size of the sample under consideration. In recent years, high resolution micro finite element methods have been extensively used to specifically address the mechanical properties of the trabecular bone and provide unique tools to interpret and model the mechanical testing experiments. The aims of the current work are to first review the mechanobiology of trabecular bone and then present classical and new approaches for modeling and analyzing the trabecular bone microstructure and macrostructure and corresponding mechanical properties such as elastic properties and strength.
Bone fracture is a very common body injury. The healing process is physiologically complex, involving both biological and mechanical aspects. Following a fracture, cell migration, cell/tissue ...differentiation, tissue synthesis, and cytokine and growth factor release occur, regulated by the mechanical environment. Over the past decade, bone healing simulation and modeling has been employed to understand its details and mechanisms, to investigate specific clinical questions, and to design healing strategies. The goal of this effort is to review the history and the most recent work in bone healing simulations with an emphasis on both biological and mechanical properties. Therefore, we provide a brief review of the biology of bone fracture repair, followed by an outline of the key growth factors and mechanical factors influencing it. We then compare different methodologies of bone healing simulation, including conceptual modeling (qualitative modeling of bone healing to understand the general mechanisms), biological modeling (considering only the biological factors and processes), and mechanobiological modeling (considering both biological aspects and mechanical environment). Finally we evaluate different components and clinical applications of bone healing simulation such as mechanical stimuli, phases of bone healing, and angiogenesis.
An adhesive yet easily removable burn wound dressing represents a breakthrough in second‐degree burn wound care. Current second‐degree burn wound dressings absorb wound exudate, reduce bacterial ...infections, and maintain a moist environment for healing, but are surgically or mechanically debrided from the wound, causing additional trauma to the newly formed tissues. We have developed an on‐demand dissolvable dendritic thioester hydrogel burn dressing for second‐degree burn care. The hydrogel is composed of a lysine‐based dendron and a PEG‐based crosslinker, which are synthesized in high yields. The hydrogel burn dressing covers the wound and acts as a barrier to bacterial infection in an in vivo second‐degree burn wound model. A unique feature of the hydrogel is its capability to be dissolved on‐demand, via a thiol–thioester exchange reaction, allowing for a facile burn dressing removal.
An easily removable dressing: A hydrogel‐based dressing for second‐degree burn wounds has been synthesized and tested in vivo. It is composed of a dendritic macromonomer and a poly(ethylene glycol) crosslinker that form a hydrogel upon mixing. An on‐demand and atraumatic hydrogel dissolution proceeds through thiol–thioester exchange reaction in presence of a cysteine methyl ester solution.
This systematic review aims to provide an overview of the current knowledge on the role of the metaverse, augmented reality, and virtual reality in reverse shoulder arthroplasty.
A systematic review ...was performed using the PRISMA guidelines. A comprehensive review of the applications of the metaverse, augmented reality, and virtual reality in in-vivo intraoperative navigation, in the training of orthopedic residents, and in the latest innovations proposed in ex-vivo studies was conducted.
A total of 22 articles were included in the review. Data on navigated shoulder arthroplasty was extracted from 14 articles: seven hundred ninety-three patients treated with intraoperative navigated rTSA or aTSA were included. Also, three randomized control trials (RCTs) reported outcomes on a total of fifty-three orthopedics surgical residents and doctors receiving VR-based training for rTSA, which were also included in the review. Three studies reporting the latest VR and AR-based rTSA applications and two proof of concept studies were also included in the review.
The metaverse, augmented reality, and virtual reality present immense potential for the future of orthopedic surgery. As these technologies advance, it is crucial to conduct additional research, foster development, and seamlessly integrate them into surgical education to fully harness their capabilities and transform the field. This evolution promises enhanced accuracy, expanded training opportunities, and improved surgical planning capabilities.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background:
Numerous treatment options have been proposed for enthesopathy of the extensor carpi radialis brevis (eECRB).
Purpose:
To (1) compare the efficacy and safety of nonsurgical treatment ...options for eECRB described in randomized placebo-controlled trials at short-term, midterm, and long-term follow-up and (2) evaluate outcomes in patients receiving placebo.
Study Design:
Systematic review and meta-analysis.
Methods:
Following PRISMA guidelines, 4 electronic databases were searched for randomized placebo-controlled trials for eECRB. Studies reporting visual analog scale (VAS) for pain scores and/or grip strength were included. Random- or fixed-effects meta-analysis was employed to compare treatments with at least 2 eligible studies using the standardized mean difference and odds ratio. The study protocol was registered at PROSPERO (ID: CRD42018075009).
Results:
Thirty-six randomized placebo-controlled trials, evaluating 11 different treatment modalities, with a total of 2746 patients were included. At short-term follow-up, only local corticosteroid injection improved pain; however, it was associated with pain worse than placebo at long-term follow-up. At midterm follow-up, laser therapy and local botulinum toxin injection improved pain. At long-term follow-up, extracorporeal shock wave therapy provided pain relief. With regard to grip strength, only laser therapy showed better outcomes in comparison with placebo. While there was no difference among various treatments in the odds ratio of an adverse event, they all increased adverse events compared with placebo. In placebo-receiving patients, a sharp increase in the percentage of patients reporting mild pain or less was observed from 2% at short-term follow-up to 92% at midterm follow-up.
Conclusion:
Most patients experienced pain resolution after receiving placebo within 4 weeks of follow-up. At best, all treatments provided only small pain relief while increasing the odds of adverse events. Therefore, if clinicians are inclined to provide a treatment for particular patients, they may consider a pain relief regimen for the first 4 weeks of symptom duration. Patient-specific factors should be considered when deciding on treatment or watchful waiting.
Background:
There is a lack of evidence regarding the optimum extensor-sided fixation method for medial patellofemoral ligament (MPFL) reconstruction. There is increased interest in avoiding patellar ...drilling via soft tissue–only fixation to the distal quadriceps, thus reconstructing the medial quadriceps tendon–femoral ligament (MQTFL). The biomechanical implications of differing extensor-sided fixation constructs remain unknown.
Hypothesis:
The null hypothesis was there would be no differences between traditional MPFL reconstruction and MQTFL reconstruction with respect to resistance to lateral translation, patellar position, or patellofemoral contact pressures.
Study Design:
Controlled laboratory study.
Methods:
Nine adult knee specimens were mounted on a jig that applied static, physiologic loads to the quadriceps tendons. Patellar position and orientation, knee flexion angle, and patellofemoral pressure were recorded at 8 different flexion angles between 0° and 110°. Additionally, a lateral patellar excursion test was conducted wherein a load was applied directly to the patella in the lateral direction with the knee at 30° of flexion and subjected to 2-N quadriceps loads. Testing was conducted under 4 conditions: intact, transected MPFL, MQTFL reconstruction, and MPFL reconstruction. For MQTFL reconstruction, the surgical technique established by Fulkerson was employed. For MPFL reconstruction, a traditional technique was utilized.
Results:
The patellar excursion test showed no significant difference between the MQTFL and intact states with respect to lateral translation. MPFL reconstruction led to significantly less lateral translation (P < .05) than all other states. There were no significant differences between MPFL and MQTFL reconstructions with respect to peak patellofemoral contact pressure. MPFL and MQTFL reconstructions both resulted in increased internal rotation of the patella with the knee in full extension.
Conclusion:
Soft tissue-only extensor-sided fixation to the distal quadriceps (MQTFL) during patella stabilization appears to re-create native stability in this time 0 cadaver model. Fixation to the patella (MPFL) was associated with increased resistance to lateral translation.
Clinical Relevance:
Evolving anatomic knowledge and concern for patellar fracture has led to increased interest in MQTFL reconstruction. Both MQTFL and MPFL reconstructions restored patellofemoral stability to lateral translation without increasing contact pressures under appropriate graft tensioning, with MQTFL more closely restoring native resistance to lateral translation at the time of surgery.
Purpose To assess the changes in tibiofemoral contact pressure and contact area in human knees with a horizontal cleavage tear before and after treatment. Methods Ten human cadaveric knees were ...tested. Pressure sensors were placed under the medial meniscus and the knees were loaded at twice the body weight for 20 cycles at 0°, 10°, and 20° of flexion. Contact area and pressure were recorded for the intact meniscus, the meniscus with a horizontal cleavage tear, after meniscal repair, after partial meniscectomy (single leaflet), and after subtotal meniscectomy (double leaflet). Results The presence of a horizontal cleavage tear significantly increased average peak contact pressure and reduced effective average tibiofemoral contact area at all flexion angles tested compared with the intact state ( P < .03). There was approximately a 70% increase in contact pressure after creation of the horizontal cleavage tear. Repairing the horizontal cleavage tear restored peak contact pressures and areas to within 15% of baseline, statistically similar to the intact state at all angles tested ( P < .05). Partial meniscectomy and subtotal meniscectomy significantly increased average peak contact pressure and reduced average contact area at all degrees of flexion compared with the intact state ( P < .05). Conclusions The presence of a horizontal cleavage tear in the medial meniscus causes a significant reduction in contact area and a significant elevation in contact pressure. These changes may accelerate joint degeneration. A suture-based repair of these horizontal cleavage tears returns the contact area and contact pressure to nearly normal, whereas both partial and subtotal meniscectomy lead to significant reductions in contact area and significant elevations in contact pressure within the knee. Repairing horizontal cleavage tears may lead to improved clinical outcomes by preserving meniscal tissue and the meniscal function. Clinical Relevance Understanding contact area and peak contact pressure resulting from differing strategies for treating horizontal cleavage tears will allow the surgeon to evaluate the best strategy for treating his or her patients who present with this meniscal pathology.
Fragility hip fractures and their associated morbidity and mortality pose a global healthcare problem. Several pharmaceutical products have been postulated to alter bone architecture and contribute ...to fragility hip fractures. We searched four electronic databases from inception to September 2017. Inclusion criteria were the following: (1) adult patients with fragility hip fractures, (2) full text in English, (3) minimum one-year follow-up, and (4) reporting of at least one risk factor. To minimize heterogeneity among the studies, we performed subgroup analyses. Whenever heterogeneity remained significant, we employed random effect meta-analysis for data pooling. Thirty-eight studies were included, containing 1,244,155 subjects and 188,966 cases of fragility hip fractures. Following medications were significantly associated with fragility hip fractures: Antidepressants (OR 2.07, 95% CI 1.98–2.17), antiparkinsonian drugs (OR 2.21, 95% CI 1.15–4.24), antipsychotic drugs (OR 2.0, 95% CI 1.50–2.66), anxiolytic drugs (OR 1.44, 95% CI 1.19–1.75), benzodiazepines (OR 1.84, 95% CI 1.26–2.69), sedatives (OR 1.33, 95% CI 1.14–1.54), systemic corticosteroids (OR 1.65, 95% CI 1.37–1.99), H
2
antagonists (OR 1.21, 95% CI 1.18–1.24), proton pump inhibitors (OR 1.41, 95% CI 1.16–1.71), and thyroid hormone (OR 1.29, 95% CI 1.13–1.47). Hormone replacement therapy with estrogen (HRT) was associated with decreased risk of hip fracture (OR 0.80, 95% CI 0.65–0.98). There are several medications associated with sustaining a fragility hip fracture. Medical interventions should be considered for patients on these medications, including information about osteoporosis and fracture prevention.
PDF
