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Frontiers in Neuroscience 2023In tissue engineering, the decellularization of organs and tissues as a biological scaffold plays a critical role in the repair of neurodegenerative diseases. Various... (Review)
Review
In tissue engineering, the decellularization of organs and tissues as a biological scaffold plays a critical role in the repair of neurodegenerative diseases. Various protocols for cell removal can distinguish the effects of treatment ability, tissue structure, and extracellular matrix (ECM) ability. Despite considerable progress in nerve regeneration and functional recovery, the slow regeneration and recovery potential of the central nervous system (CNS) remains a challenge. The success of neural tissue engineering is primarily influenced by composition, microstructure, and mechanical properties. The primary objective of restorative techniques is to guide existing axons properly toward the distal end of the damaged nerve and the target organs. However, due to the limitations of nerve autografts, researchers are seeking alternative methods with high therapeutic efficiency and without the limitations of autograft transplantation. Decellularization scaffolds, due to their lack of immunogenicity and the preservation of essential factors in the ECM and high angiogenic ability, provide a suitable three-dimensional (3D) substrate for the adhesion and growth of axons being repaired toward the target organs. This study focuses on mentioning the types of scaffolds used in nerve regeneration, and the methods of tissue decellularization, and specifically explores the use of decellularized nerve tissues (DNT) for nerve transplantation.
PubMed: 37928728
DOI: 10.3389/fnins.2023.1295563 -
Scientific Reports Dec 2023Biological scaffolds for airway reconstruction are an important clinical need and have been extensively investigated experimentally and clinically, but without uniform...
Biological scaffolds for airway reconstruction are an important clinical need and have been extensively investigated experimentally and clinically, but without uniform success. In this study, we evaluated the use of a decellularized bronchus graft for airway reconstruction. Decellularized left bronchi were procured from decellularized porcine lungs and utilized as grafts for airway patch transplantation. A tracheal window was created and the decellularized bronchus was transplanted into the defect in a porcine model. Animals were euthanized at 7 days, 1 month, and 2 months post-operatively. Histological analysis, immunohistochemistry, scanning electron microscopy, and strength tests were conducted in order to evaluate epithelialization, inflammation, and physical strength of the graft. All pigs recovered from general anesthesia and survived without airway obstruction until the planned euthanasia timepoint. Histological and electron microscopy analyses revealed that the decellularized bronchus graft was well integrated with native tissue and covered by an epithelial layer at 1 month. Immunostaining of the decellularized bronchus graft was positive for CD31 and no difference was observed with immune markers (CD3, CD11b, myeloperoxidase) at two months. Although not significant, tensile strength was decreased after one month, but recovered by two months. Decellularized bronchial grafts show promising results for airway patch reconstruction in a porcine model. Revascularization and re-epithelialization were observed and the immunological reaction was comparable with the autografts. This approach is clinically relevant and could potentially be utilized for future applications for tracheal replacement.
Topics: Swine; Animals; Tissue Engineering; Tissue Scaffolds; Transplantation, Autologous; Bronchi; Trachea
PubMed: 38066170
DOI: 10.1038/s41598-023-48643-y -
Arthroscopy : the Journal of... Mar 2024To assess the statistical fragility of recently published randomized controlled trials (RCTs) comparing the use of hamstring tendon autograft with bone-patellar... (Review)
Review
Randomized Controlled Trials Comparing Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autografts in Anterior Cruciate Ligament Reconstruction Surgery Are Statistically Fragile: A Systematic Review.
PURPOSE
To assess the statistical fragility of recently published randomized controlled trials (RCTs) comparing the use of hamstring tendon autograft with bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction.
METHODS
The PubMed, Embase, and MEDLINE databases were queried for RCTs published since 2010 comparing autograft type (bone-patellar tendon-bone vs hamstring tendon) in ACL reconstruction surgery. The fragility index (FI) and reverse FI (rFI) were determined for significant and nonsignificant outcomes, respectively, as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) and reverse FQ, representing fragility as a proportion of the study population, were calculated by dividing the FI and rFI, respectively, by the sample size.
RESULTS
We identified 19 RCTs reporting 55 total dichotomous outcomes. The median FI of the 55 total outcomes was 5 (interquartile range [IQR], 4-7), meaning a median of 5 outcome event reversals would alter the outcomes' significance. Five outcomes were reported as statistically significant with a median FI of 4 (IQR, 2-6), meaning a median of 4 outcome event reversals would change outcomes to be nonsignificant. Fifty outcomes were reported as nonsignificant with a median rFI of 5 (IQR, 4-7), meaning a median of 5 outcome event reversals would change outcomes to be significant. The FQ and reverse FQ for significant and nonsignificant outcomes were 0.025 (IQR, 0.018-0.045) and 0.082 (IQR, 0.041-0.106), respectively. For 61.8% of outcomes, patients lost to follow-up exceeded the corresponding FI or rFI.
CONCLUSIONS
There is substantial statistical fragility in recent RCTs on autograft choice in ACL reconstruction surgery given that altering a few outcome events is sufficient to reverse study findings. For over half of outcomes, maintaining patients lost to follow-up may have been sufficient to reverse study conclusions.
CLINICAL RELEVANCE
We recommend co-reporting FIs and P values to provide a more comprehensive representation of a study's conclusions when conducting an RCT.
Topics: Humans; Patellar Ligament; Autografts; Hamstring Tendons; Bone-Patellar Tendon-Bone Grafting; Anterior Cruciate Ligament Injuries; Randomized Controlled Trials as Topic; Anterior Cruciate Ligament Reconstruction; Transplantation, Autologous
PubMed: 37543146
DOI: 10.1016/j.arthro.2023.07.039 -
Macromolecular Bioscience Nov 2023Several years have passed since the medical and scientific communities leaned toward tissue engineering as the most promising field to aid bone diseases and defects... (Review)
Review
Several years have passed since the medical and scientific communities leaned toward tissue engineering as the most promising field to aid bone diseases and defects resulting from degenerative conditions or trauma. Owing to their histocompatibility and non-immunogenicity, bone grafts, precisely autografts, have long been the gold standard in bone tissue therapies. However, due to issues associated with grafting, especially the surgical risks and soaring prices of the procedures, alternatives are being extensively sought and researched. Fibrous and non-fibrous materials, synthetic substitutes, or cell-based products are just a few examples of research directions explored as potential solutions. A very promising subgroup of these replacements involves hydrogels. Biomaterials resembling the bone extracellular matrix and therefore acting as 3D scaffolds, providing the appropriate mechanical support and basis for cell growth and tissue regeneration. Additional possibility of using various stimuli in the form of growth factors, cells, etc., within the hydrogel structure, extends their use as bioactive agent delivery platforms and acts in favor of their further directed development. The aim of this review is to bring the reader closer to the fascinating subject of hydrogel scaffolds and present the potential of these materials, applied in bone and cartilage tissue engineering and regeneration.
Topics: Tissue Engineering; Tissue Scaffolds; Hydrogels; Biocompatible Materials; Bone and Bones
PubMed: 37276333
DOI: 10.1002/mabi.202300152 -
Annals of Plastic Surgery Jan 2024Nerve capping is a method of neuroma treatment or prevention that consists of the transplantation of a proximal nerve stump into an autograft or other material cap,... (Review)
Review
BACKGROUND/AIM OF THE STUDY
Nerve capping is a method of neuroma treatment or prevention that consists of the transplantation of a proximal nerve stump into an autograft or other material cap, after surgical removal of the neuroma or transection of the nerve. The aim was to reduce neuroma formation and symptoms by preventing neuronal adhesions and scar tissue. In this narrative literature review, we summarize the studies that have investigated the effectiveness of nerve capping for neuroma management to provide clarity and update the clinician's knowledge on the topic.
METHODS
A systematic electronic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria was performed in the PubMed database combining "neuroma," "nerve," "capping," "conduit," "treatment," "management," "wrap," "tube," and "surgery" as search terms. English-language clinical studies on humans and animals that described nerve capping as a treatment/prevention technique for neuromas were then selected based on a full-text article review. The data from the included studies were compiled based on the technique and material used for nerve capping, and technique and outcomes were reviewed.
RESULTS
We found 10 applicable human studies from our literature search. Several capping materials were described: epineurium, nerve, muscle, collagen nerve conduit, Neurocap (synthetic copolymer of lactide and caprolactone, which is biocompatible and resorbable), silicone rubber, and collagen. Overall, 146 patients were treated in the clinical studies. After surgery, many patients were completely pain-free or had considerable improvement in pain scores, whereas some patients did not have improvement or were not satisfied after the procedure. Nerve capping was used in 18 preclinical animal studies, using a variety of capping materials including autologous tissues, silicone, and synthetic nanofibers. Preclinical studies demonstrated successful reduction in rates of neuroma formation.
CONCLUSIONS
Nerve capping has undergone major advancements since its beginnings and is now a useful option for the treatment or prevention of neuromas. As knowledge of peripheral nerve injuries and neuroma prevention grows, the criterion standard neuroprotective material for enhancement of nerve regeneration can be identified and applied to produce reliable surgical outcomes.
Topics: Animals; Humans; Amputation Stumps; Collagen; Neuroma; Peripheral Nerve Injuries; Peripheral Nerves
PubMed: 37962245
DOI: 10.1097/SAP.0000000000003714 -
The American Journal of Sports Medicine Oct 2023Recently, interest in anterior cruciate ligament (ACL) preservation and repair after proximal ACL tears has been resurrected. Although good clinical outcomes have been...
Favorable Patient-Reported, Clinical, and Functional Outcomes 2 Years After ACL Repair and InternalBrace Augmentation Compared With ACL Reconstruction and Healthy Controls.
BACKGROUND
Recently, interest in anterior cruciate ligament (ACL) preservation and repair after proximal ACL tears has been resurrected. Although good clinical outcomes have been reported in the literature with adequate patient selection, to date detailed scientific evidence for the functional benefit of primary ACL repair with ligament augmentation is scarce.
PURPOSE
To compare patient-reported, clinical, and functional outcomes in patients 2 years after ACL repair and InternalBrace augmentation (ACL-IB) with age- and sex-matched patients 2 years after ACL reconstruction (ACL-R) and with matched healthy controls.
STUDY DESIGN
Cohort study; Level of evidence, 3.
METHODS
In total, 29 patients 2 years after ACL-IB, 27 sex- and age- matched patients 2 years after ACL-R (hamstring autografts), and 29 matched healthy controls were included. Patient-reported outcomes were assessed using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, EQ-5D-5L, Tegner Activity Scale, and Anterior Cruciate Ligament Return to Sports after Injury scale. Surgery time was recorded. For clinical outcomes, range of motion and thigh and shank circumference were measured, and passive anterior translation was determined using the Rolimeter. Isokinetic muscle strength was measured using a Biodex dynamometer. The limb symmetry index (operated/contralateral or nondominant/dominant × 100), side-to-side differences (operated - contralateral, nondominant - dominant), and hamstring-quadriceps ratios were calculated for functional parameters. Failure and reoperation rates were not compared.
RESULTS
Two years after surgery, patients treated with ACL-IB showed good to excellent patient-reported outcomes comparable with those of patients after ACL-R. Surgery time, including concomitant surgeries, was significantly shorter in the ACL-IB group (mean, 81 minutes) compared with the ACL-R group (mean, 97 minutes) ( = .024). Isokinetic muscle strength was comparable between patient groups without significant differences in extensor and flexor strength or in hamstring-quadriceps ratios.
CONCLUSION
These results suggest that ACL-IB achieves comparable patient-reported, clinical, and functional outcomes with ACL-R at 2 years postoperatively and, after careful patient selection, should be considered as a valuable early treatment alternative for proximal ACL tears.
REGISTRATION
NCT04429165 (ClinicalTrials.gov identifier).
Topics: Humans; Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Cohort Studies; Treatment Outcome; Patient Reported Outcome Measures
PubMed: 37675973
DOI: 10.1177/03635465231194784 -
Orthopaedic Journal of Sports Medicine Jun 2024Several approaches to surgical techniques and graft types exist in posterolateral corner (PLC) reconstruction. The literature lacks knowledge regarding outcomes after... (Review)
Review
BACKGROUND
Several approaches to surgical techniques and graft types exist in posterolateral corner (PLC) reconstruction. The literature lacks knowledge regarding outcomes after autograft versus allograft reconstruction for PLC injuries.
PURPOSE
To comprehensively review the current literature on PLC reconstruction and compare outcomes between autograft and allograft tissues.
STUDY DESIGN
Systematic review; Level of evidence, 4.
METHODS
The PubMed and Scopus online databases were searched with the terms "PLC,""posterolateral knee,""posterolateral corner," and "reconstruction" in varying combinations. Patient characteristics, graft type, graft failure, surgical techniques, functional outcome scores, and varus laxity on stress radiographs were reviewed and compared between PLC reconstruction with autografts versus allografts.
RESULTS
Included were 22 studies comprising 33 cohorts: 16 autografts (n = 280 knees) and 17 allografts (336 knees). There were 69 isolated PLC reconstructions (58 allografts and 11 autografts) and 493 multiligament reconstructions (269 autografts and 224 allografts). There was no difference in the mean patient age (30.5 vs 33.5 years, respectively; = .11) or mean follow-up (39.5 vs 37.7 months, respectively; = .68) between the autograft and allograft groups. There was no evidence to suggest a difference in graft failures between graft types (pooled mean autograft vs allograft: 0.44 vs 0.41 failures; = .95). There was a significant difference in the mean postoperative Lysholm scores for autografts versus allografts (89.6 vs 85.5, respectively; = .04). There was no difference between the cohorts in preoperative or postoperative International Knee Documentation Committee (IKDC) scores or postoperative varus laxity.
CONCLUSION
Our review and meta-analysis indicated no significant differences in graft failure rates or objective outcomes after PLC reconstruction based on graft type alone. There was a significant difference in postoperative Lysholm scores in favor of the autograft group and no significant difference in IKDC subjective scores.
PubMed: 38840793
DOI: 10.1177/23259671241247542 -
International Journal of Spine Surgery Dec 2023Degenerative spine disease is increasing in prevalence as the global population ages, indicating a need for targeted therapies and continued innovations. While autograft...
Degenerative spine disease is increasing in prevalence as the global population ages, indicating a need for targeted therapies and continued innovations. While autograft and allograft have historically demonstrated robust results in spine fusion surgery, they have significant limitations and associated complications such as infection, donor site morbidity and pain, and neurovascular injury. Synthetic grafts may provide similar success while mitigating negative outcomes. A narrative literature review was performed to review available synthetic materials that aim to optimize spinal fusion. The authors specifically address the evolution of synthetics and comment on future trends. Novel synthetic materials currently in use include ceramics, synthetic polymers and peptides, bioactive glasses, and peptide amphiphiles, and the authors focus on their success in both human and animal models, physical properties, advantages, and disadvantages. Advantages include properties of osteoinduction, osteoconduction, and osteogenesis, whereas disadvantages encompass a lack of these properties or growth factor-induced complications. Typically, the use of synthetic materials results in fewer complications and lower costs. While the development and tuning of synthetic materials are ongoing, there are many beneficial alternatives to autografts and allografts with promising fusion results.
PubMed: 37748919
DOI: 10.14444/8557 -
Arthroscopy : the Journal of... Aug 2023Superior capsular reconstruction is a viable option for select patients with massive irreparable rotator cuff tears. Graft integrity at short- and mid-term follow-up...
Superior capsular reconstruction is a viable option for select patients with massive irreparable rotator cuff tears. Graft integrity at short- and mid-term follow-up directly correlates with range of motion, functional outcome, and radiographic outcome. Historically, various graft options have been proposed, including dermal allograft, fascia lata autograft, and synthetic graft choices. With a traditional dermal allograft and fascia lata autograft, the graft retear rates have been variably reported. Because of this uncertainty, newer techniques using the healing capabilities of autografts in conjunction with the structural integrity of synthetic materials have emerged in an effort to decrease graft failure rates. Preliminary results are promising; however, longer-term follow-up with head-to-head comparison with traditional techniques is required to understand their true efficacy.
Topics: Humans; Rotator Cuff; Autografts; Rotator Cuff Injuries; Transplantation, Autologous; Wound Healing; Range of Motion, Articular; Fascia Lata; Shoulder Joint
PubMed: 37400167
DOI: 10.1016/j.arthro.2023.03.016