Soft Tissue Repair Research Articles

Three dimensional porous scaffolds derived from collagen, elastin and fibrin proteins orchestrate adipose tissue regeneration

Current gold standard to treat soft tissue injuries caused by trauma and pathological condition are autografts and off the shelf fillers, but they have inherent weaknesses like donor site morbidity, immuno-compatibility and graft failure. To overcome these limitations, tissue-engineered polymers are seeded with stem cells to improve the potential to restore tissue function. However, their interaction with native tissue is poorly understood so far. To study these interactions and improve outcomes, we have fabricated scaffolds from natural polymers (collagen, fibrin and elastin) by custom-designed processes and their material properties such as surface morphology, swelling, wettability and chemical cross-linking ability were characterised. By using 3D scaffolds, we comprehensive assessed survival, proliferation and phenotype of adipose-derived stem cells in vitro. In vivo, scaffolds were seeded with adipose-derived stem cells and implanted in a rodent model, with X-ray microtomography, histology and immunohistochemistry as read-outs. Collagen-based materials showed higher cell adhesion and proliferation in vitro as well as higher adipogenic properties in vivo. In contrast, fibrin demonstrated poor cellular and adipogenesis properties but higher angiogenesis. Elastin formed the most porous scaffold, with cells displaying a non-aggregated morphology in vitro while in vivo elastin was the most degraded scaffold. These findings of how polymers present in the natural polymers mimicking ECM and seeded with stem cells affect adipogenesis in vitro and in vivo can open avenues to design 3D grafts for soft tissue repair.

Initial Experience With a Bioresorbable Polymer Anchor.

BackgroundAnchors are frequently used in reconstructive orthopedic surgery to achieve fixation of soft tissue to bone. Anchors vary with respect to material composition, configuration, and methods of fixation at the site of attachment. The fixation component of anchoring devices has generally evolved from metal-fabricated implants to various types of bioresorbable anchors. The SonicAnchorTM (Stryker, Kalamazoo, MI USA) polymer implant provides a unique form of anchor fixation using SonicFusionTM technology to achieve interdigitation within cancellous bone while being radiolucent and providing a small footprint.MethodsDuring a four-year period, 116 patients underwent a reconstructive orthopedic foot and ankle surgical procedure with the use of at least one bioresorbable polymer anchor (SonicAnchor implant). There were 59 males and 57 females, with an average age of 42 years (range: 12-83 years).ResultsA total of 233 bioresorbable anchor (SonicAnchor) implants were used in 116 patients. Of the 116 patients, 108 (93.1%) achieved successful clinical healing of their surgery at their most recent follow-up. The average follow-up duration was 309 days (range: 14-1,429 days). Eight (6.9%) patients were lost to follow-up prior to clinical healing. Two (1.7%) patients underwent reoperation. Also, 65 (56%) patients had at least six months of follow-up and 36 (31%) had at least one year of follow-up.ConclusionsThis preliminary clinical trial of patients undergoing soft tissue repair or reconstruction with a bioresorbable polymer appears to perform comparably to other commercially available devices. The lack of adverse events, mechanical failures, or infections further supports the safety of this device.

Surgical Treatment of Upper Extremity Gunshot Injures: An Updated Review.

Firearm morbidity and mortality have been increasing in recent years, and with this, the demand for medical personnel firearm injury treatment knowledge. Extremities contribute to a majority of firearm injuries, with these injuries being particularly complex because of neurovascular proximity within a confined space. Knowledge of firearm mechanism of injury and treatment management options is important for any trauma hand surgeon. Many factors play vital roles in the treatment of complex upper extremity (UE) gunshot wounds (GSWs). The aim of our review and case illustrations is to provide hand surgeons with an up-to-date guide for initial emergent management, soft tissue, bony, and nerve repair and reconstruction. A literature review was conducted in the current management of UE GSW injuries, and 2 specific patient case examples were included. High-energy versus low-energy GSWs were documented and compared, as well as containment injures. Management including soft tissue, bony, and nerve injuries was explored along with patient outcome. Based on these findings, guidelines for GSW management were purposed. Gunshot wounds of the UE encompass a group of highly heterogeneous injuries. High-energy wounds are more extensive, and concomitant injuries to bone, vessel, nerve, muscle, and soft tissue are common. Early treatment with adequate debridement, skeletal fixation, and soft tissue coverage is indicated for complex injuries, and antibiotic treatment in the pre-, peri-, and postoperative period is indicated for operative injuries. Soft tissue coverage options include the entire reconstructive ladder, with pattern of injury and considerations of wound characteristics dictating reconstructive choice. There are arguments to using either external or internal bony fixation techniques for bone fracture management, with choice tailored to the patient. For management of nerve injuries, we advocate earlier nerve repair and a shorter duration of observation before secondary reconstruction in selective cases. If transected nerve endings cannot be brought together, nerve autografts of shorter length are recommended to bridge nerve ending gaps. A significant number of patients with GSW fail to make necessary follow-up appointments, which adds to challenges in treatment.

3D-Bioprinted Inflammation Modulating Polymer Scaffolds for Soft Tissue Repair.

Development of inflammation modulating polymer scaffolds for soft tissue repair with minimal postsurgical complications is a compelling clinical need. However, the current standard of care soft tissue repair meshes for hernia repair is highly inflammatory and initiates a dysregulated inflammatory process causing visceral adhesions and postsurgical complications. Herein, the development of an inflammation modulating biomaterial scaffold (bioscaffold) for soft tissue repair is presented. The bioscaffold design is based on the idea that, if the excess proinflammatory cytokines are sequestered from the site of injury by the surgical implantation of a bioscaffold, the inflammatory response can be modulated, and the visceral adhesion formations and postsurgical complications can be minimized. The bioscaffold is fabricated by 3D-bioprinting of an in situ phosphate crosslinked poly(vinyl alcohol) polymer. In vivo efficacy of the bioscaffold is evaluated in a rat ventral hernia model. In vivo proinflammatory cytokine expression analysis and histopathological analysis of the tissues have confirmed that the bioscaffold acts as an inflammation trap and captures the proinflammatory cytokines secreted at the implant site and effectively modulates the local inflammation without the need for exogenous anti-inflammatory agents. The bioscaffold is very effective in inhibiting visceral adhesions formation and minimizing postsurgical complications.

Use of Surgical Approach Is Not Associated With Instability After Primary Total Hip Arthroplasty: A Meta-analysis Comparing Direct Anterior and Posterolateral Approaches.

Posterolateral approach (PA) has been historically associated with an increased risk of dislocation after primary total hip arthroplasty (THA), especially when compared with the direct anterior approach (DAA). However, current evidence is inconsistent regarding the risk of dislocation with either approach. The purpose of this study is to determine whether surgical approach influences joint stability. A systematic search in PubMed, MEDLINE, and Embase databases was performed. Randomized controlled trials (RCTs) and non-RCTs comparing DAA with PA in primary THA were included. Pooled effect measure of risk differences, relative risk and mean differences for postoperative dislocation, acetabular implant positioning, and leg length discrepancy were calculated. Twenty-five studies (5 RCTs and 20 non-RCTs) of 7,172 THAs were assessed. There were no significant differences in dislocation rates between approaches (risk difference = -0.00, 95% confidence interval: -0.01 to 0.00; P = 0.92; I2 = 0%). Results were similar in the subgroup analysis of RCTs (P = 0.98), posterior soft-tissue repair (P = 0.50), and learning curve (P = 0.77). The acetabular implant was better positioned within the safe zone in the DAA group (relative risk = 1.17; 95% confidence interval: 1.03 to 1.33; P = 0.01), but no significant differences were found in cup inclination (P = 0.8), anteversion (P = 0.10), and leg length discrepancy (P = 0.54). Dislocation rates after THA are not different between DAA and PA. Furthermore, no differences in the rate of dislocation were associated with cup positioning or surgical factors related with hip instability. Therefore, the surgical approach has little influence in prosthesis instability after primary THA. Level III.

Should the surgical intervention of the hands and wrists of patients with rheumatoid arthritis be earlier

Aim: Few studies have been published about early surgical treatment of Rheumatoid Arthritis (RA). This article has aimed to describe the main procedures that may be performed in the hands of subjects at early stages of this disease. Methods: This research was a narrative review seeking comparative works in the Medline, LILACs and EMBASE databases. Results: The publications showed good results associated with wrist synovectomy. There was a reduction in pain, greater patient satisfaction, and stabilization of the Larsen score. Synovectomy was indicated in these studies as an alternative procedure after three to four months of unsatisfactory clinical therapy. Another possibility of approaching these patients is the repair or transfer of ruptured tendons. Most studies have described this procedure in patients already with deformities secondary to RA and not in the initial phase of the disease. In this group of patients, the authors observed that the highest number of ruptures was associated with worse surgical outcomes. In most studies about wrists, radiolunate and RA were performed at more advanced stages, such as Larsen 3, and, even performed late, a clinical and radiological improvement was observed. Conclusion: In this review, no studies with a high level of scientific evidence, testing early surgical interventions on the hands and wrists of patients with RA were found. Synovectomy, soft tissue repair, and arthrodesis are suggested as procedures that can be performed earlier than usual.

Composite bone and skin flap transplantation combined with bone lengthening for repairing lower limb burn with soft tissue and bone defect

To compare the effect of traditional fibula flap combined with allogeneic bone transplantation and composite bone flap transplantation combined with bone lengthening in staged repair of severe soft tissue and bone defect caused by lower limb burn. Total 68 patients with severe soft tissue and bone defect caused by lower limb burn from March 2015 to January 2018 were retrospectively analyzed, and they were divided into control group (34 cases) and study group (34 cases) according to the treatment plan. All patients had different degrees of soft tissue and bone tissue defects. In the study group, 34 patients were treated with composite bone flap transplantation combined with bone lengthening. There were 22 males and 12 females; the age ranged from 32 to 46(39.18±6.01) years; the time from injury to treatment was (16.69±5.11) h;28 cases were caused by explosion injury and 6 cases were caused by firearm burn; the length of bone defect was (12.10± 2.34) cm;and 16 cases were on the left side of affected limb 18 cases were on the right side. In the control group, there were 24 males and 10 females, aged 31 to 47 (38.93 ± 5.81) years;the time from injury to treatment was(17.10±5.63) h;the causes of injury were explosive injury in 30 cases and firearm burn in 4 cases; the length of bone defect was (11.96±2.51) cm;19 cases were on the left side and 15 cases on the right side. All patients were followed up for 6 months. The FMA scores before operation and 3 and 6 months after operation, treatment satisfaction, curative effect and complications of the two groups were recorded. Limb function:there was no significant difference in FMA scores between the two groups before operation (P> 0.05), and the FMA scores of the two groups were higher than those before operation 3 and 6 months after operation(P<0.05), and the FMA scores of the studygroup were higher than those of the control group (P<0.05). At 6 months after operation:the excellent and good rate of the study group (94.12%) was higher than that of the control group (76.47%)(P<0.05), the treatment satisfaction of the study group (94.12%) was higher than that of the control group(76.47%)(P<0.05). Complications:the incidence of complications in the study group (14.71%) was higher than that in the control group (26.47%) (P>0.05). the combined use of composite bone flap transplantation and bone lengthening staged repair in the treatment of severe soft tissue and bone defect caused by lower limb burn can achieve good therapeutic effect, improve limb function, and have high treatment satisfaction and certain safety.

Transosseous versus transmuscular repair of the posterior soft tissue in primary hip arthroplasty: a meta-analysis

BackgroundDuring the posterior approach, it has been shown that a significant reduction in dislocation rate can be achieved with the repair of the posterior soft tissue. However, no consensus exists about the best way to perform this repair. This review aimed to compare the transosseous with transmuscular repair of the posterior soft tissue in total hip arthroplasty (THA).MethodsWe conducted a meta-analysis to identify studies involving transosseous versus transmuscular repair of the posterior soft tissue in THA in electronic databases, including Web of Science, Embase, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, Wanfang database, up to July 2020. Finally, we identified 1417 patients (1481 hips) assessed in seven studies.ResultsCompared with transmuscular repair, transosseous repair resulted in less incidence of dislocation (P = 0.003), less blood loss during operation (P < 0.00001) and lower VAS score within 3 months (P = 0.02). There were no significant differences in terms of trochanteric fracture rate (P = 0.56), Harris hip score at 3 months (P = 0.35) and 6 months (P = 0.89), VAS score within 6 months (P = 0.53), and operation time (P = 0.70) between two groups.ConclusionThe lower dislocation rate, less blood loss, and lower VAS scores after operation supported transosseous repair's superiority to transmuscular repair. Besides, no additional medical cost and operating time were associated with transosseous repair compared with transmuscular repair. Hence, we recommend that transosseous repair be chosen first by orthopedists when performing reconstruction of the posterior soft tissue in THA via a posterolateral approach. Given the relevant possible biases in our meta-analysis, we required more adequately powered and better-designed RCT studies with long-term follow-up to reach a firmer conclusion.

Leech Therapy for Complex Facial Lacerations.

Facial trauma can pose challenging reconstructive obstacles in both maintaining tissue viability and restoring aesthetic appearance. Medicinal leech therapy can help to promote vascular decompression in the setting of venous congestion. A retrospective chart review was conducted to identify patients who underwent medicinal leech therapy following venous stasis secondary to repair of a complex facial laceration. Three patients were identified; 2 suffered auricular avulsion, while 1 suffered a lip avulsion. All patients suffered from venous congestion and underwent medicinal leech therapy for 48 to 72 hours with reduction of edema and stasis. Decompression was successfully achieved with no further sequelae on last follow-up. Medicinal leech therapy is an adequate treatment for venous congestion following traumatic soft-tissue repair of the face. The authors advocate for the utilization of medicinal leeches to combat venous congestion after repair, particularly when arterial inflow remains intact.

Chromophore‐Free Sealing and Repair of Soft Tissues Using Mid‐Infrared Light‐Activated Biosealants

AbstractPoor strength, infection, leakage, long procedure times, and inflammation limit the efficacy of common tissue sealing devices in surgeries and trauma. Light‐activated sealing is attractive for tissue sealing and repair, and can be facilitated by the generation of local heat following absorption of nonionizing laser energy by chromophores. Here, the inherent ability of biomaterials is exploited to absorb nonionizing, mid‐infrared (midIR) light in order to engender rapid photothermal sealing and repair of soft tissue wounds. In this approach, the biomaterial simultaneously acts as a photothermal convertor as well as a biosealant, which dispenses the need for exogeneous light‐absorbing nanoparticles or dyes. Biomechanical recovery, mathematical modeling, histopathology analyses, tissue strain mapping using digital imaging correlation, and visualization of the biosealant‐tissue interface using hyperspectral imaging indicate superior performance of midIR sealing in live mice compared to conventional sutures and glue. The midIR‐biosealant approach demonstrates rapid sealing of soft tissues, improves cosmesis, lowers potential for scarring, obviates safety concerns because of the nonionizing light used, and allows adoption of a wide diversity of biomaterials. Taken together, the studies demonstrate a novel advance both in biomaterials for surgical sealing along with the use of nonionizing midIR light, with high potential for clinical translation.

Low cost 3D printed clamps for external fixator for developing countries: a biomechanical study

BackgroundExternal fixation is a mainstream limb reconstruction technique, most often used after a traumatic injury. Due to the high rates of trauma in developing countries, external fixation devices are often utilized for immediate fracture stabilization and soft tissue repair. Proper external fixation treatment too often still fails to be adopted in these regions due to the high cost and trauma complexity. A novel, inexpensive, unilateral fixator was constructed using 3D printed clamps and other readily available supporting components. ASTM standard F1541 tests were used to assess the biomechanical properties of this novel external fixator.MethodsApplicable sections of ASTM standard F1541 were used to determine the biomechanical properties of the novel external fixator. 3D printed clamps modeled using SolidWorks and printed with chopped carbon fibers using a fuse deposition modeling (FDM) based 3D printer by Markforged (Boston, MA) were used. This study included 3 different testing configurations: axial compression, anterior-posterior (AP) bending, and medial-lateral (ML) bending. Using the novel unilateral fixator with 3D printed clamps previously sterilized by autoclave, an input load was applied at a rate of 20 N/s, starting at 0 N via a hydraulic MTS tester Model 359. Force and deformation data were collected at a sampling rate of 30 Hz. There was a load limit of 750 N, or until there was a maximum vertical deformation of 6 mm. Also, 4 key dimensions of the 3D printed clamps were measured pre and post autoclave: diameter, width, height and length.ResultsThe novel external fixator had axial compression, AP and ML bending rigidities of 246.12 N/mm (σ = 8.87 N/mm), 35.98 N/mm (σ = 2.11 N/mm) and 39.60 N/mm (σ =2.60 N/mm), respectively. The 3D printed clamps shrunk unproportionally due to the autoclaving process, with the diameter, width, height and length dimensions shrinking by 2.6%, 0.2%, 1.7% and 0.3%, respectively.ConclusionOverall, the biomechanical properties of the novel fixator with 3D printed clamps assessed in this study were comparable to external fixators that are currently being used in clinical settings. While the biomechanics were comparable, the low cost and readily available components of this design meets the need for low cost external fixators in developing countries that current clinical options could not satisfy. However, further verification and validation routines to determine efficacy and safety must be conducted before this novel fixator can be clinically deployed. Also, the material composition allowed for the clamps to maintain the appropriate shape with minimal dimensional shrinkage that can be accounted for in clamp design.

Craniofacial Trauma Due to Stone-pelting - Patterns of Injury and Management.

The aims of the study were to elucidate the pattern of stone-pelting induced cranio-facial injuries and to document soft and hard tissue injuries, their management, and complications. A retrospective descriptive study was conducted using a sample of patients reporting to our department in the years 2015 to 2020. Cranio-facial injuries were assessed for soft and hard tissue injuries, including tissue loss, and corresponding management. Follow up ranged from 18 ± 6 months. & A standardized surgical regime was followed for patient management, which included primary survey, debridement of wounds, and routine primary repair of soft tissue. Bony defect reconstruction was performed by open reduction and internal fixation. Cranial bone was used as split calvarial graft in postcraniectomy cranioplasty procedures, which were performed after 6 months. Local flaps were used for the reconstruction of soft tissue defects. Being a military hospital, majority of cases fell in the 20 to 30 age group with a male preponderance. The etiology in all cases was stone-pelting. Among cranio-facial injuries, cranial vault injuries and mid-face injuries (71%) were most prevalent, mandibular fractures (24%) and remaining were soft tissue injuries (5%). & Frontal & parietal bone injuries were seen in 23.6% cases (n = 9) and orbito-zygomatic complex injuries were seen in (36.8%) cases (n = 14). Isolated blow-out fractures were seen in 4 patients of our series. 52.6% of patients of our series suffered associated soft tissue injuries to the head, face, and neck region. The most common cause of injury was due to the direct impact of stone hitting the mid-face/cranial vault and the most common pattern of injury was gross comminution of the skeleton. & 2 patients suffered ocular injuries that required management and 6 patients of our series who suffered head injuries to the cranium required a secondary cranioplasty procedure (n = 4) &The most commonly used technique for treatment was open reduction internal fixation, which was used in 89% of patients. Soft-tissue injuries overall occurred most frequently on the forehead, nose, lips, and chin which was managed by primary suturing. Cranial vault injuries & orbito-zygomatic complex fractures are most commonly seen in patients with stone-pelting injuries. Early management of such injuries improves outcomes in terms of function and restitution of preinjury skeleton structure. The most common patterns seen is gross comminution to the cranio-facial skeleton that can be treated with immediate primary wound repair after meticulous wound debridement and open reduction and internal fixation. Importance of stone-pelting as a cause of craniofacial injuries is highlighted as it leads to significant disruption of craniofacial skeleton.

An update to the advances in understanding distraction histogenesis: From biological mechanisms to novel clinical applications

Over the past 3 decades, Ilizarov technique namely distraction histogenesis (DH) technique has been widely accepted and applied in orthopaedics and traumatology with outstanding clinical outcomes and emerging novel applications. This review focuses on the recent advances in understanding the biological mechanisms of DH, new methods for promoting bone consolidation in DH procedures and novel clinical applications of DH techniques. Tension stress regulates many genes during DH, including signaling transduction molecules, BMPs, inflammatory and angiogenic factors as well as epigenetic factors. DH also triggers systemic responses such as recruitment of mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs). These activities play important roles in regulating bone regeneration and remodeling during DH. To promote bone formation in DH is still a clinical challenge, and minimal or non-invasive means for promoting bone consolidation are preferable, such as weight-bearing exercise, ultrasound and electromagnetic stimuli; whereas systemic administration of anabolic agents and hormones may also achieve better outcomes. Local cell transplantation and application of various biological factors at the right time may also be the choices. With better understanding of the biological mechanisms, applications of DH technique have now been extended for managing skin wound, joint disorders and avascular diseases. However, more basic or clinical researches are still needed to unravel the “magic” of DH technique. DH technique awakens and promotes human body’s self-regeneration potentials and leads to many novel treatment strategies. A substantial number of methods have been found to promote bone consolidation in DH to shorten the treatment duration and make the application of DH easier. Novel clinical applications of DH technique have now been extended to management of soft-tissue repair disorders, avascular diseases and others, with many more new biological mechanisms yet to be defined. A full understanding of DH technique may facilitate its wider and more appropriate clinical applications.

How Much Physical Guidance is Needed to Orient Growing Axons in 3D Hydrogels?

Directing cells is essential to organize multi-cellular organisms that are built up from subunits executing specific tasks. This guidance requires a precisely controlled symphony of biochemical, mechanical, and structural signals. While many guiding mechanisms focus on 2D structural patterns or 3D biochemical gradients, injectable material platforms that elucidate how cellular processes are triggered by defined 3D physical guiding cues are still lacking but crucial for the repair of soft tissues. Herein, a recently developed anisotropic injectable hybrid hydrogel (Anisogel) contains rod-shaped microgels that orient in situ by a magnetic field and has propelled studying 3D cell guidance. Here, the Anisogel is used to investigate the dependence of axonal guidance on microgel dimensions, aspect ratio, and distance. While large microgels result in high material anisotropy, they significantly reduce neurite outgrowth and thus the guidance efficiency. Narrow and long microgels enable strong axonal guidance with maximal outgrowth including cell sensing over distances of tens of micrometers in 3D. Moreover, nerve cells decide to orient inside the Anisogel within the first three days, followed by strengthening of the alignment, which goes along with oriented fibronectin deposition. These findings demonstrate the potential of the Anisogel to tune structural and mechanical parameters for specific applications.

Clinical Safety and Outcomes of a Novel Ultrasound Assisted Bioabsorbable Suture Anchor in Foot and Ankle Surgeries

Category:SportsIntroduction/Purpose:Bioabsorbable suture anchors have been popularized due to potential for osseous integration, less interference with diagnostic imaging, and ease of use. Recently, ultrasound assisted suture anchor systems have been introduced with the benefits of obtaining interdigitation with cancellous bone while maintaining a minimal footprint. In a cadaveric study, ultrasound assisted suture anchors demonstrated a similar pullout strength and less system displacement when compared to a benchmark bioabsorbable anchor system. However, the failure and complication rates of ultrasound assisted bioabsorbable anchors has never been demonstrated in a clinical setting. We studied the Stryker SonicAnchor by examining complication rates in foot and ankle procedures and secondarily determined the efficacy by evaluating clinical outcomes of surgeries using this anchor system.Methods:A retrospective analysis was performed on all patients treated by the primary investigator using the Stryker SutureAnchor between the dates of May 2016 and February 2018. We included all patients for which the anchor was used during surgery with at least 2 year followup including VAS and FAOS scores. We recorded baseline demographic information as well as the type of surgery patients underwent. We recorded all intraoperative and postoperative complications for these surgeries. In addition, we compared preoperative and postoperative clinical scores.Results:57 patients met inclusion criteria. On average, patients were 53 years old at the time of surgery. Mean followup was 32.8 months. Mean BMI was 30.36. Three patients reported current tobacco use (5.3%), four patients (7.0%) had type II diabetes mellitus at the time of their surgery, and only one patient (1.8%) had osteoporosis. Common procedures were Achilles repair including Haglund’s resection, peroneal surgery, and lateral ligament reconstruction. There were two deep infections requiring reoperation, one medial malleolus stress fracture following total ankle replacement, one metatarsal stress fracture not involving the surgery site, and one DVT. No reports of anchor pullout or soft tissue repair failure. VAS and FAOS scores improved from 6.2 to 1.2 and 54.3 to 93.9.Conclusion:In our review of 57 patients operated on with the SonicAnchor with at least two year followup, there were zero cases of complications stemming from the anchor including anchor pullout or soft tissue repair failure. Overall, patients improved tremendously in their clinical outcome scores across a wide range of different procedures. Previous studies have demonstrated the biomechanical strength of the SonicAnchor and our review supports its clinical safety and efficacy in long-term clinical followup.

Dental nerves: a neglected mediator of pulpitis.

As one of the most densely innervated tissues, the dental pulp contains abundant nerve fibres, including sensory, sympathetic and parasympathetic nerve fibres. Studies in animal models and human patients with pulpitis have revealed distinct alterations in protein expression and histological appearance in all types of dental nerve fibres. Various molecules secreted by neurons, such as classical neurotransmitters, neuropeptides and amino acids, not only contribute to the induction, sensitization and maintenance of tooth pain, but also regulate non-neuronal cells, including fibroblasts, odontoblasts, immune cells and vascular endothelial cells. Dental nerves are particularly important for the microcirculatory and immune responses in pulpitis via their release of a variety of functional substances. Further, nerve fibres are found to be involved in dental soft and hard tissue repair. Thus, understanding how dental nerves participate in pulpitis could have important clinical ramifications for endodontic treatment. In this review, the roles of dental nerves in regulating pulpal inflammatory processes are highlighted and their implications for future research on this topic are discussed.

Synthetic Polymeric Antibacterial Hydrogel for Methicillin-Resistant Staphylococcus aureus-Infected Wound Healing: Nanoantimicrobial Self-Assembly, Drug- and Cytokine-Free Strategy.

Antibacterial hydrogels are attracting extensive attention in soft tissue repair and regeneration, including bacteria-infected-wound healing. The abuse of antibiotics leads to drug resistance. Recent developments have demonstrated that the delivery of inorganic bactericidal agents in hydrogels can drive the wound healing process; however, this approach is complicated by external light stimuli, cytotoxicity, nondegradability, and sophisticated fabrication. Herein, an inherent antibacterial, bioresorbable hydrogel was developed by the spontaneous self-aggregation of amphiphilic, oxadiazole-group-decorated quaternary ammonium salts (QAS)-conjugated poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCEC-QAS) micellar nanoantimicrobials for methicillin-resistant Staphylococcus aureus (MRSA)-infected cutaneous wound healing. The PCEC-QAS hydrogel showed a stable gel state within the temperature range of 5-50 °C and antibacterial efficacy against both Gram-negative and -positive bacteria in vitro and in vivo. Additionally, the PCEC-QAS hydrogel facilitated the cell spreading, proliferation, and migration without cytotoxicity. An in vivo degradation and skin defect healing study suggested the PCEC-QAS hydrogel was totally absorbed without local or systemic toxicity and could promote wound repair in the absence of drugs, cytokines, or cells. Significantly, this hydrogel accelerated the regeneration of a MRSA-infected full-thickness impaired skin wound by successfully reconstructing an intact and thick epidermis similar to normal mouse skin. Collectively, a self-assembling PCEC-QAS antibacterial hydrogel is a promising dressing material to promote skin regeneration and prevent bacterial infection without additional drugs, cells, light irradiation, or delivery systems, providing a simple but effective strategy for treating dermal wounds.

A Specific Capsular Repair Technique Lowered Early Dislocations in Primary Total Hip Arthroplasty Through a Posterior Approach

BackgroundDislocation is a challenging problem after total hip arthroplasty (THA). We sought to evaluate the incidence of early dislocation with 2 different posterior repair techniques after THA using a posterior approach. MethodsFrom September of 2008 to August of 2019, we evaluated 841 THAs performed by a single surgeon using a posterior approach. Before November of 2015, the capsule was repaired to the greater trochanter (group 1, 605 patients). Starting November 2015, the posterior capsule was repaired in a side-to-side fashion (direct soft-tissue repair) (group 2, 236 patients). There was a mean follow-up of 31.1 months (range, 2.5-122.5 months). A multivariable logistic regression model was constructed to assess the impact of baseline patient and operative factors on the dislocation rate. ResultsThere were 22 dislocations, all of which occurred in group 1. There were no dislocations in group 2. After adjusting for patient and operative factors, the direct soft-tissue repair had a large impact on the overall multivariable model as indicated by its effect likelihood ratio of 10.33 (P = .001); however, the odds ratio was not calculable for this factor, given that there were no dislocations in hips with direct soft-tissue repair. Increasing age was associated with an increased odds of dislocation (odds ratio, 1.04, P = .017), with an effect likelihood ratio of 6.25 (P = .012). ConclusionsSwitching from a capsular repair to the greater trochanter to a side-to-side capsular repair was associated with a decreased rate of dislocation in primary THA through a posterior approach.

Is the Bacterial Cellulose Membrane Feasible for Osteopromotive Property?

Guided bone regeneration was studied to establish protocols and develop new biomaterials that revealed satisfactory results. The present study aimed to comparatively evaluate the efficiency of the bacterial cellulose membrane (Nanoskin®) and collagen membrane Bio-Gide® in the bone repair of 8-mm critical size defects in rat calvaria. Seventy-two adult male rats were divided into three experimental groups (n = 24): the CG—membrane-free control group (only blood clot, negative control), BG—porcine collagen membrane group (Bio-Guide®, positive control), and BC—bacterial cellulose membrane group (experimental group). The comparison periods were 7, 15, 30, and 60 days postoperatively. Histological, histometric, and immunohistochemical analyses were performed. The quantitative data were subjected to 2-way ANOVA and Tukey’s post-test, and p < 0.05 was considered significant. At 30 and 60 days postoperatively, the BG group showed more healing of the surgical wound than the other groups, with a high amount of newly formed bone (p < 0.001), while the BC group showed mature connective tissue filling the defect. The inflammatory cell count at postoperative days 7 and 15 was higher in the BC group than in the BG group (Tukey’s test, p = 0.006). At postoperative days 30 and 60, the area of new bone formed was greater in the BG group than in the other groups (p < 0.001). Immunohistochemical analysis showed moderate and intense immunolabeling of osteocalcin and osteopontin at postoperative day 60 in the BG and BC groups. Thus, despite the promising application of the BC membrane in soft-tissue repair, it did not induce bone repair in rat calvaria.

Electrospun PCL Fiber Mats Incorporating Multi-Targeted B and Co Co-Doped Bioactive Glass Nanoparticles for Angiogenesis.

Vascularization is necessary in tissue engineering to keep adequate blood supply in order to maintain the survival and growth of new tissue. The synergy of biologically active ions with multi-target activity may lead to superior angiogenesis promotion in comparison to single-target approaches but it has been rarely investigated. In this study, polycaprolactone (PCL) fiber mats embedded with B and Co co-doped bioactive glass nanoparticles (BCo.BGNs) were fabricated as a tissue regeneration scaffold designed for promoting angiogenesis. BCo.NBGs were successfully prepared with well-defined spherical shape using a sol-gel method. The PCL fiber mats embedding co-doped bioactive glass nanoparticles were fabricated by electrospinning using benign solvents. The Young’s moduli of the nanoparticle containing PCL fiber mats were similar to those of the neat fiber mats and suitable for scaffolds utilized in soft tissue repair approaches. The mats also showed non-cytotoxicity to ST-2 cells. PCL fiber mats containing BCo.BGNs with a relatively high content of B and Co promoted the secretion of vascular endothelial growth factor to a greater extent than PCL fiber mats with a relatively low B and Co contents, which demonstrates the potential of dual ion release (B and Co) from bioactive glasses to enhance angiogenesis in soft tissue engineering.