Fluorescence identification of arthropathic calcium pyrophosphate single crystals using alizarin red S and a xanthene dipicolylamine ZnII complex.

Calcium pyrophosphate deposition disease, previously known as pseudogout, is a type of chronic and painful joint arthropathy. Accurate identification of calcium pyrophosphate dihydrate (CPPD) single crystals is crucial for determining the best course of treatment. In this study, a two-step method involving alizarin red S (ARS) and a xanthene dipicolylamine ZnII (XDZ) complex was employed for the identification of CPPD single crystals in both triclinic and monoclinic forms using a fluorescence microscope and a microplate reader. The accurate identification method proposed in this study has the potential to advance the diagnosis and treatment of patients suffering from painful gouty arthritis.

Validation of a novel magnetic resonance imaging classification and recommended treatment for lateral elbow tendinopathy.

BACKGROUND: Lateral epicondylitis is one of the most common upper extremity problems presented to orthopedic surgeons. Despite a rapid and accurate arrival at a diagnosis by clinical examination, there exists no consensus classification for this condition, which hampers clinical approaches for treatment of the disease based on its severity. Thus, the aim of this study was to propose and valiadate a new magnetic resonance imaging (MRI) classification of lateral epicondylitis, staging by tendinosis, the degree of thickness tears of the common extensor tendon (CET) and bone bruise lesion. METHOD: MRI assessment of the elbow of 75 patients (57 women and 18 men; mean age:51.4 years (range,34-73) from Jan 2014 to Jan 2021 who were diagnosed with lateral epicondylitis were included in the study. MR images were reviewed retrospectively by two independent upper extremities orthopedists and one musculoskeletal radiologist. Inter- and intra-observer reliabilities for the classification were calculated using kappa statistics for the analysis of interrater agreement. Correlation between the stage of the disease and the duration of symptom before MRI was calculated using Kruskal-wallis test. RESULTS: Various degrees of CET lesions were demonstrated in this population (Stage I-17, IIA-7, IIB-22 and III-29). Intra-observer agreements of MRI staging were substantial to satisfactory. Inter-observer agreements were moderate to substantial. There was no significant correlation between the disease stage and the patient age or the duration of symptom before MRI. CONCLUSION: Our MRI classification has emerged as one of the most reliable methods to define stages of chronic lateral epicondylitis. At the end, we have suggeted a clearer direction for understanding the disease pathology as well as an appropriate management protocol for each stage of the disease in line with the recent body of literature.

Annexin A2 Improves the Osteogenic Differentiation of Mesenchymal Stem Cells Exposed to High-Glucose Conditions through Lessening the Senescence.

Osteoporosis is frequently found in chronic diabetic patients, and it results in an increased risk of bone fractures occurring. The underlying mechanism of osteoporosis in diabetic patients is still largely unknown. Annexin A2 (ANXA2), a family of calcium-binding proteins, has been reported to be involved in many biological process including bone remodeling. This study aimed to investigate the role of ANXA2 in mesenchymal stem cells (MSCs) during in vitro osteoinduction under high-glucose concentrations. Osteogenic gene expression, calcium deposition, and cellular senescence were determined. The high-glucose conditions reduced the osteogenic differentiation potential of the MSCs along with the lower expression of ANXA2. Moreover, the high-glucose conditions increased the cellular senescence of the MSCs as determined by senescence-associated ß-galactosidase staining and the expression of p16, p21, and p53 genes. The addition of recombinant ANXA2 could recover the glucose-induced deterioration of the osteogenic differentiation of the MSCs and ameliorate the glucose-induced cellular senescence of the MSCs. A Western blot analysis revealed an increase in p53 and phosphorylated p53 (Ser 15), which was decreased by recombinant ANXA2 in MSC osteoblastic differentiation under high-glucose conditions. Our study suggested that the alteration of ANXA2 in high-glucose conditions may be one of the plausible factors in the deterioration of bones in diabetic patients by triggering cellular senescence.

P-cresol and Indoxyl Sulfate Impair Osteogenic Differentiation by Triggering Mesenchymal Stem Cell Senescence.

Chronic kidney disease (CKD) patients obtained high levels of uremic toxins progressively develop several complications including bone fractures. Protein-bound uremic toxins especially p-cresol and indoxyl sulfate are hardly eliminated due to their high molecular weight. Thus, the abnormality of bone in CKD patient could be potentially resulted from the accumulation of uremic toxins. To determine whether protein-bound uremic toxins have an impact on osteogenesis, mesenchymal stem cells were treated with either p-cresol or indoxyl sulfate under in vitro osteogenic differentiation. The effects of uremic toxins on MSC-osteoblastic differentiation were investigated by evaluation of bone phenotype. The results demonstrated that p-cresol and indoxyl sulfate down-regulated the transcriptional level of collagen type I, deceased alkaline phosphatase activity, and impaired mineralization of MSC-osteoblastic cells. Furthermore, p-cresol and indoxyl sulfate gradually increased senescence-associated beta-galactosidase positive cells while upregulated the expression of p21 which participate in senescent process. Our findings clearly revealed that the presence of uremic toxins dose-dependently influenced a gradual deterioration of osteogenesis. The effects partially mediate through the activation of senescence-associated gene lead to the impairment of osteogenesis. Therefore, the management of cellular senescence triggered by uremic toxins could be considered as an alternative therapeutic approach to prevent bone abnormality in CKD patients.

Proteomic study of in vitro osteogenic differentiation of mesenchymal stem cells in high glucose condition.

Patients with diabetes have been widely reported to be at an increased risk of secondary osteoporosis. Osteoporosis is caused by an imbalance in bone remodeling due to increased bone resorption and/or decreased osteoblast-dependent bone formation. In this study, mesenchymal stem cells (MSCs) were used as a disease model to determine the effects of high glucose levels on MSC-osteoblast development. The results indicated that under high glucose conditions, MSCs had reduced cell viability and increased number of ß-galactosidase-positive cells. Furthermore, in vitro osteogenesis was shown to be reduced in MSCs cultured in osteogenic differentiation medium at 10, 25, and 40 mM glucose as demonstrated by Alizarin red S staining and alkaline phosphatase activity assay. Moreover, a proteomic study was performed in MSCs cultured with 25 and 40 mM glucose. The proteomic results demonstrated that 12 proteins were up- and downregulated in bone marrow-derived mesenchymal stem cells cultured with high glucose in a dose-dependent manner. The findings presented here contribute to our understanding of the mechanism of diabetes mellitus responsible for bone loss. However, the exact mechanism of action of hyperglycemia on bone deformability requires additional studies.

Fluorescence Differentiation of ATP-related Multiple Enzymatic Activities in Synovial Fluid as a Marker of Calcium Pyrophosphate Deposition Disease using Kyoto Green.

Calcium pyrophosphate deposition disease (CPPD) is a crystal induced inflammation in joints, and causes severe pain in elderly people. The accumulation of pyrophosphate (PPi) in synovial fluid (SF) results from several enzymatic reactions, especially the highly activated e-NPPs, which catalyze the conversion of ATP to PPi. This study demonstrates the detection of relative catalytic activity of 3 enzymes-ecto-nucleotide pyrophosphatase/phosphodiesterases (e-NPPs), tissue nonspecific alkaline phosphatase (TNAP), and ecto-nucleoside triphosphate diphosphohydrolases (e-NTPDases)-using a single molecular sensor called Kyoto Green. Kyoto Green exhibits excellent performance in sensing the catalytic activity of the commercial representatives of the e-NPPs, TNAP, and e-NTPDases, which are ENPP1, PPase, and apyrase, respectively, in both single-enzyme and multi-enzyme assays. Analysis of SF enzymes in 19 SF samples from human and swine revealed moderate activity of e-NPPs, high activity of e-NTPDases, and low activity of TNAP. Our newly developed method for analysis of multiple enzymatic activities using Kyoto Green in biological SF will assist improvement in accuracy of the CPPD prognosis/diagnosis, which will minimize unnecessary medical procedures.

The Lateral Antebrachial Neurocutaneous Flap: A Cadaveric Study and Clinical Applications.

BACKGROUND: The neurocutaneous flap is an axial pattern flap that receives a vascular supply from a vessel along its cutaneous nerve and has favorable outcomes when used for soft tissue reconstruction in the upper extremities. The neurocutaneous flap depends on the lateral antebrachial cutaneous nerve (LACN) and its retrograde-flow has been studied via cadaveric dissection. The aim of this study is to prove the vascularity of the lateral antebrachial neurocutaneous (LABN) flap. METHODS: The distally based LABN flap was created in 18 upper limbs (12 cadavers). The skin flap was dissected at the proximal half of the forearm and then diluted methylene blue was injected through the brachial artery. The pedicle of the flap on the distal half of the forearm was dissected along the LACN for the anatomical study of the perforating branches, paraneural vessels, and flap territory. RESULTS: The mean age of cadavers was 74.1 years (nine males). The mean distance of most distal and proximal perforating branches from the radial styloid process were 2.32 ± 0.59 and 11.17 ± 1.72 cm, respectively. The mean total number of perforating branches was 7.4, which abundantly appeared approximately 4 to 5 cm from the radial styloid process. The mean flap territory was 8.64 ± 0.82 cm in width and 10.50 ± 1.90 cm in length. The mean forearm circumference was 24.84 ± 1.52 cm, and mean forearm length was 24.74 ± 1.8 cm. CONCLUSION: This study ensured that retrograde-flow via the neurocutaneous artery could be provided through the vascularity of the LABN flap, which suggests that the pivot point of the flap should not extend beyond 5 cm proximal to the radial styloid process. The LABN flap is a useful alternative method for performing soft tissue reconstruction in hand and wrist defects without sacrificing the major vessels.

Chitosan oligosaccharide suppresses synovial inflammation via AMPK activation: An in vitro and in vivo study.

Synovial inflammation plays an important role in the early pathogenesis of osteoarthritis (OA). Chitosan oligosaccharide (COS) has been shown to activate AMPK and suppress inflammatory responses in intestinal epithelial cells. This study aimed to investigate the effect of COS on AMPK activation and synovial inflammation using both primary cultures of synoviocytes and a rabbit model of anterior cruciate ligament (ACL) transection-induced OA. COS induced AMPK activation in both rabbit and human synoviocytes. The mechanism of COS-induced AMPK activation involves an increase in the ADP/ATP ratio but not calcium/calmodulin-dependent protein kinase kinase beta (CaMKKß). Interestingly, COS suppressed the TNFα-induced iNOS and COX-2 expression via an AMPK-dependent mechanism in both rabbit and human synoviocytes. Importantly, oral administration of COS (10mg/kg/day) induced AMPK activation and alleviated signs of inflammation including COX-2 expression in the synovium of a rabbit ACL transection model. Taken together, our results indicate that COS suppresses synovial inflammation in vitro and in vivo via AMPK activation. COS may be useful in the prevention of OA.

Extensor tendons and variations of the medial four digits of hand: a cadaveric study.

A total of 100 cadaveric limbs were dissected to study the anatomy of the forearm and hand extensor musculature. Four types of contributions to the index finger were found for the extensor indicis proprius (EIP), including one new type where the double tendons of the EIP inserts volar and radial to the extensor digitorum communis of the index finger (EDC-I). Four variant muscles were identified including the extensor medii proprius (EMP) (in five cadavers), extensor digitorum brevis manus (EDBM) (in one cadaver), extensor indicis et medii communis (EIMC) (in four cadavers) and extensor pollicis et indicis (EPI) (in four cadavers). The absence of the EIP in four cases was substituted by either the EIMC or the EPI. Two unpreviously published cases were found. In one hand, the variant EIMC was present along with the EPI. In another hand, both the EMP and the EDBM were present, and the EMP tendon inserted to the tendon of the EDBM. Awareness of the variations on the dorsum of the hand is essential for diagnosis, surgical planning and treatment of diseased hands.

Natural history of mesenchymal stem cells, from vessel walls to culture vessels.

Mesenchymal stem/stromal cells (MSCs) can regenerate tissues by direct differentiation or indirectly by stimulating angiogenesis, limiting inflammation, and recruiting tissue-specific progenitor cells. MSCs emerge and multiply in long-term cultures of total cells from the bone marrow or multiple other organs. Such a derivation in vitro is simple and convenient, hence popular, but has long precluded understanding of the native identity, tissue distribution, frequency, and natural role of MSCs, which have been defined and validated exclusively in terms of surface marker expression and developmental potential in culture into bone, cartilage, and fat. Such simple, widely accepted criteria uniformly typify MSCs, even though some differences in potential exist, depending on tissue sources. Combined immunohistochemistry, flow cytometry, and cell culture have allowed tracking the artifactual cultured mesenchymal stem/stromal cells back to perivascular anatomical regions. Presently, both pericytes enveloping microvessels and adventitial cells surrounding larger arteries and veins have been described as possible MSC forerunners. While such a vascular association would explain why MSCs have been isolated from virtually all tissues tested, the origin of the MSCs grown from umbilical cord blood remains unknown. In fact, most aspects of the biology of perivascular MSCs are still obscure, from the emergence of these cells in the embryo to the molecular control of their activity in adult tissues. Such dark areas have not compromised intents to use these cells in clinical settings though, in which purified perivascular cells already exhibit decisive advantages over conventional MSCs, including purity, thorough characterization and, principally, total independence from in vitro culture. A growing body of experimental data is currently paving the way to the medical usage of autologous sorted perivascular cells for indications in which MSCs have been previously contemplated or actually used, such as bone regeneration and cardiovascular tissue repair.

The Association of Bone Mineral Density and G2014A Polymorphism in the Estrogen Receptor Alpha Gene in Osteoporotic Hip Fracture in Thai Population.

OBJECTIVE: This study aimed to determine the association of a recent identified G2014A single nucleotide polymorphism (SNP) genotype distribution in exon 8 of the estrogen receptor in postmenopausal Thai women. MATERIAL AND METHOD: A prospective study was conducted at Ramathibodi Hospital between July 2005 and July 2006. Postmenopausal Thai women, aged more than 55 years and had sustained osteoporotic hipfracture, were included. Exclusion criteria were renal and metabolic bone diseases. Age, body mass index (BMI), blood tests for metabolic bone disease, and G2014A SNP genotype, bone mineral density (BMD) were collected. The relationship between the degree of osteoporosis (normal, osteopenia, and osteoporosis) and SNP genotype was analyzed by Fisher's exact test. RESULTS: Sixty-five postmenopausal women with osteoporosis were included. The average age was 76.2 ± 10.9 years old, and the average BMI was 21.3 ± 3.5 kg/m2. The data expressing the genotype distribution of gene G2014A SNP were G/G 23.1%, G/A 29.2% and A/A 47.7%. There was no statistical difference between age and BMI in each genotype. Gene G2014A was associated with osteoporosis of lumbar spine, femoral neck, ward triangle, and femoral neck. CONCLUSION: It could be concluded that a G2014A SNP genotype in exon 8 of the estrogen receptor was associated with postmenopausal women who had osteoporotic hip fracture.

Shaft-Condylar Angle for surgical correction in neglected and displaced lateral humeral condyle fracture in children.

PURPOSE: To assess the outcome after using the Shaft-Condylar angle (SCA) as intraoperative reference for sagittal plane correction in displaced lateral humeral condyle fractures in children presented 3-weeks after injury. METHODS: Ten children, with delayed presentation of a displaced lateral humeral condyle fracture and undergoing surgery during 1999-2011, were reviewed. The goal was to obtain a smooth articular surface with an intraoperative SCA of nearly 40° and nearest-anatomical carrying angle. They were allocated into two groups according to the postoperative SCA [Good-reduction group (SCA=30-50°), and Bad-reduction group (SCA<30°, >50°)] and the final outcomes were then compared. RESULTS: All fractures united without avascular necrosis. The Good-reduction group (n=7) showed a significant improvement in final range of motion and functional outcome compared to the Bad-reduction group (n=3) (p=0.02). However, there was no significant difference in pain, carrying angle and overall outcome between both groups. CONCLUSION: SCA is a possible intraoperative reference for sagittal alignment correction in late presented displaced lateral humeral condyle fractures.

The sensory restoration in radial nerve injury using the first branch of dorsal ulnar cutaneous nerve--a cadaveric study for the feasibility of procedure and case demonstration.

OBJECTIVE: To demonstrate the new sensory restoration technique in radial nerve injury using the first branch of dorsal ulnar cutaneous nerve as the donor sensory nerve. MATERIAL AND METHOD: Forty formalin-preserved cadavers (18 males and 22 females) were used as the subjects of the present study. The localization of the origin of first branch of dorsal ulnar cutaneous nerve was performed. The measurement was done to determine the origin of this nerve in relation to the tip of ulnar styloid. The simulated transfer was done. The length of the superficial radial nerve that had to be cut was determined. The measurement was done by two observers to determine the reliability of measurement. RESULTS: The mean horizontal distance (X) to the origin of first branch of dorsal ulnar cutaneous nerve measured from the tip of ulnar styloid on the right and left side were 5.22 mm and 6.51 mm respectively. The mean vertical distance (Y) to the origin of first branch of dorsal ulnar cutaneous nerve measured from the tip of ulnar styloid on the right and left side were -7.72 mm and -4.37 mm respectively. The mean length of superficial radial nerve that had to be cut to allow tension free anastomosis, measured from the tip of radial styloid on the right and left side were 68.21 mm and 65.92 mm respectively. The estimated average size of the transferred branch of ulnar cutaneous nerve was about 70% of the size of superficial radial nerve. CONCLUSION: The sensory restoration in radial nerve injury using sensory nerve transfer from the first branch of dorsal ulnar cutaneous nerve was technically feasible regarding to the comparable size between two nerves and anatomic consistency of the first branch of dorsal ulnar cutaneous nerve.

Double lesion of TFCC injury from penetrating wrist trauma: A case report.

Bony avulsion injuries of the triangular fibrocartilage complex (TFCC) caused by penetrating wrist trauma are rare, and there is limited literature available regarding their treatment. This case report describes a 54-year-old male who sustained a penetrating injury to his right wrist, resulting in "double lesion" of TFCC injury, which are ulnar avulsion (Palmer 1B) and radial avulsion (Palmer 1D) lesion with a sigmoid notch fracture. The patient underwent an arthroscopic examination and a novel arthroscopic technique for fixation and repair of the TFCC injury. The procedure involved debridement, repair of the dorsal radioulnar ligament bony avulsion, and fixation of the foveal bony avulsion of the TFCC. The patient's wrist was immobilized postoperatively, followed by gradual rehabilitation. At the final follow-up of six months, the patient demonstrated improved range of motion and functional outcomes. This case report highlights the successful use of arthroscopic techniques for the treatment of complex TFCC avulsion injuries resulting from penetrating wrist trauma.

The extracts of osteoblast developed from adipose-derived stem cell and its role in osteogenesis.

Cell-based therapy has become an achievable choice in regenerative medicines, particularly for musculoskeletal disorders. Adipose-derived stem cells (ASCs) are an outstanding resource because of their ability and functions. Nevertheless, the use of cells for treatment comes with difficulties in operation and safety. The immunological barrier is also a major limitation of cell therapy, which can lead to unexpected results. Cell-derived products, such as cell extracts, have gained a lot of attention to overcome these limitations. The goal of this study was to optimize the production of ASC-osteoblast extracts as well as their involvement in osteogenesis. The extracts were prepared using a freeze-thaw method with varying temperatures and durations. Overall, osteogenic-associated proteins and osteoinductive potential of the extracts prepared from the osteogenic-induced ASCs were assessed. Our results demonstrated that the freeze-thaw approach is practicable for cell extracts production, with minor differences in temperature and duration having no effect on protein concentration. The ASC-osteoblast extracts contain a significant level of essential specialized proteins that promote osteogenicity. Hence, the freeze-thaw method is applicable for extract preparation and ASC-osteoblast extracts may be beneficial as an optional facilitating biologics in bone anabolic treatment and bone regeneration.

Development of Biphasic Injectable Hydrogels for Meniscus Scaffold from Photocrosslinked Glycidyl Methacrylate-Modified Poly(Vinyl Alcohol)/Glycidyl Methacrylate-Modified Silk Fibroin.

The development of a hydrogel material with a modified chemical structure of poly(vinyl alcohol) (PVA) and silk fibroin (SF) using glycidyl methacrylate (GMA) (denoted as PVA-g-GMA and SF-g-GMA) is an innovative approach in the field of biomaterials and meniscus tissue engineering in this study. The PVA-g-GMA/SF-g-GMA hydrogel was fabricated using different ratios of PVA-g-GMA to SF-g-GMA: 100/0, 75/25, 50/50, 25/75, and 0/100 (w/w of dry substances), using lithium phenyl (2,4,6-trimethylbenzoyl)phosphinate (LAP) as a free radical photoinitiator, for 10 min at a low ultraviolet (UV) intensity (365 nm, 6 mW/cm2). The mechanical properties, morphology, pore size, and biodegradability of the PVA-g-GMA/SF-g-GMA hydrogel were investigated. Finally, for clinical application, human chondrocyte cell lines (HCPCs) were mixed into PVA-g-GMA/SF-g-GMA solutions and fabricated into hydrogel to study the viability of live and dead cells and gene expression. The results indicate that as the SF-g-GMA content increased, the compressive modulus of the PVA-g-GMA/SF-g-GMA hydrogel dropped from approximately 173 to 11 kPa. The degradation rates of PVA-g-GMA/SF-g-GMA 100/0, 75/25, and 50/50 reached up to 15.61%, 17.23%, and 18.93% in 4 months, respectively. In all PVA-g-GMA/SF-g-GMA conditions on day 7, chondrocyte cell vitality exceeded 80%. The PVA-g-GMA/SF-g-GMA 75:25 and 50:50 hydrogels hold promise as a biomimetic biphasic injectable hydrogel for encapsulated augmentation, offering advantages in terms of rapid photocurability, tunable mechanical properties, favorable biological responses, and controlled degradation.

Fabrication of Fish Scale-Based Gelatin Methacryloyl for 3D Bioprinting Application.

Gelatin methacryloyl (GelMA) is an ideal bioink that is commonly used in bioprinting. GelMA is primarily acquired from mammalian sources; however, the required amount makes the market price extremely high. Since garbage overflow is currently a global issue, we hypothesized that fish scales left over from the seafood industry could be used to synthesize GelMA. Clinically, the utilization of fish products is more advantageous than those derived from mammals as they lower the possibility of disease transmission from mammals to humans and are permissible for practitioners of all major religions. In this study, we used gelatin extracted from fish scales and conventional GelMA synthesis methods to synthesize GelMA, then tested it at different concentrations in order to evaluated and compared the mechanical properties and cell responses. The fish scale GelMA had a printing accuracy of 97%, a swelling ratio of 482%, and a compressive strength of about 85 kPa at a 10% w/v GelMA concentration. Keratinocyte cells (HaCaT cells) were bioprinted with the GelMA bioink to assess cell viability and proliferation. After 72 h of culture, the number of cells increased by almost three-fold compared to 24 h, as indicated by many fluorescent cell nuclei. Based on this finding, it is possible to use fish scale GelMA bioink as a scaffold to support and enhance cell viability and proliferation. Therefore, we conclude that fish scale-based GelMA has the potential to be used as an alternative biomaterial for a wide range of biomedical applications.

The Surgical Treatment of Bilateral Accessory Extensor Carpi Ulnaris: Case Report and Literature Review.

Several abnormal pathologies, such as inflammation or degenerative change, can be causes of ulnar-sided wrist pain. This study demonstrated bilateral accessory extensor carpi ulnaris found in a patient who presented with bilateral wrist pain. The patient was initially treated with all conventional methods but failed to improve. Following the operation by releasing the sixth extensor compartment, the pain was completely relieved. The Disabilities of the Arm, Shoulder, and Hand (DASH) score was remarkably improved and there was no limitation in daily living activities compared with preoperative status. We presented an uncommon condition of ulnar-sided wrist pain caused by bilateral accessory extensor carpi ulnaris which was successfully treated by releasing the extensor compartmental sheath without tendon resection.

Reinforcement of Injectable Hydrogel for Meniscus Tissue Engineering by Using Cellulose Nanofiber from Cassava Pulp.

Injectable hydrogels can be applied to treat damaged meniscus in minimally invasive conditions. Generally, injectable hydrogels can be prepared from various polymers such as polycaprolactone (PCL) and poly (N-isopropylacrylamide) (PNIPAAm). Poly (ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer-diacrylate (PEO-PPO-PEO-DA) is an interesting polymer due to its biodegradability and can be prepared as water-insoluble injectable hydrogel after curing with UV light at low intensity. However, mechanical and cell adhesion properties are not optimal for these hydrogels. For the improved mechanical performance of the injectable hydrogel, cellulose nanofiber (CNF) extracted from cassava pulp was used as a reinforcing filler in this study. In addition, gelatin methacrylate (GelMA), the denatured form of collagen was used to enhance cell adhesion. PEO-PPO-PEO-DA/CNF/GelMA injectable hydrogels were prepared with 2-hydroxy-1-(4-(hydroxy ethoxy) phenyl)-2-methyl-1-propanone as a photoinitiator and then cured with UV light, 365 nm at 6 mW/cm2. Physicochemical characteristics of the hydrogels and hydrogels with CNF were studied in detail including morphology characterization, pore size diameter, porosity, mechanical properties, water uptake, and swelling. In addition, cell viability was also studied. CNF-reinforced injectable hydrogels were successfully prepared after curing with UV light within 10 min with a thickness of 2 mm. CNF significantly improved the mechanical characteristics of injectable hydrogels. The incorporation of GelMA into the injectable hydrogels improved the viability of human cartilage stem/progenitor cells. At optimum formulation, 12%PEO-PPO-PEO-DA/0.5%CNF/3%GelMA injectable hydrogels significantly promoted cell viability (>80%) and also showed good physicochemical properties, which met tissue engineering requirements. In summary, this work shows that these novel injectable hydrogels have the potential for meniscus tissue engineering.

Comparative Analysis of Treatment Outcomes: Modified Ulnar Gutter Slab vs. Sugar Tong Slab for Distal Radioulnar Joint Instability Following Triangular Fibrocartilage Complex Repair.

The standard treatment for distal radioulnar joint (DRUJ) instability involves repairing the triangular fibrocartilage complex (TFCC) and immobilizing the joint with a sugar tong slab, but this can cause elbow stiffness. To address this, a modified ulnar gutter slab was designed to enhance elbow mobility during immobilization. A prospective randomized controlled trial was conducted on 23 DRUJ instability patients who underwent arthroscopic TFCC repair. Two post-operative splinting techniques were compared: the modified ulnar gutter slab and the sugar tong slab. The assessment included the Disabilities of Arm, Shoulder, and Hand (DASH) score; elbow, forearm, and wrist range of motion (ROM); post-operative DRUJ stability; and complications. DASH scores at 4 and 6 weeks were not significantly different. However, the modified ulnar gutter slab improved elbow extension range of motion at 4 weeks (extension lag: 20.0 vs. 6.5 in the sugar tong group) (p = 0.011). Post-operative DRUJ stability was comparable between the two groups. Notably, one patient in the sugar tong slab group experienced complex regional pain syndrome (CRPS). The modified ulnar gutter slab offers a post-operative alternative after TFCC repair. It effectively immobilizes forearm and wrist motion while enhancing elbow mobility, potentially reducing post-operative elbow stiffness.