Midterm outcomes of midfoot and hindfoot arthrodesis with strut allograft for Müller-Weiss disease.

BACKGROUND: Müller-Weiss disease (MWD), a rare dysplastic disorder of the foot, is characterized by deformity, sclerosis, and fragmentation of the lateral part of navicular bone. Arthrodesis is the mainstay treatment for MWD. Generally, arthrodesis can be achieved through internal fixation with metallic implants, and morselized chip bone may be packed into the gap for better bone union. However, with this procedure, the original foot size is not maintained and support for the foot arch is not provided. Sequela of short foot, or flatfoot is commonly observed even though these complications of surgery had not been reported with cases of MWD treated by arthrodesis. Herein, we present a retrospective analysis of treating MWD through midfoot and hindfoot arthrodesis combined with strut allograft. METHODS: From August 2006 to June 2019, 20 patients with MWD (mean age, 59.6 years; range, 40-80 years) underwent midfoot and hindfoot arthrodesis with strut bone allograft and were followed for at least 24 months. The patients were able to ambulate and participate in rehabilitation programs 3 months postoperatively. RESULTS: The used four radiographic parameters (Meary's angle in anteroposterior and lateral view, talonavicular coverage angle, calcaneal pitch) demonstrated significant differences (P < .05) preoperatively and postoperatively, but those between the postoperative values and the values at the last follow-up session did not, indicating that strut allograft was able to maintain normal alignment. The mean American Orthopaedic Foot & Ankle Society Ankle-Hindfoot scores at 2 years postoperatively revealed significant improvement from baseline, from 60.2 to 84.2 (P < .05). The 12-item Short Form Health Survey scores also improved significantly (P < .05). All patients reported substantial pain relief and exhibited improved functional outcomes and gait patterns. CONCLUSIONS: For advanced-stage MWD, arthrodesis with a precisely shaped, size-matched strut allograft provided strong support for biomechanical alignment and enhanced functional performance.

Surgical Reconstruction with Tendon Allografting Following Iatrogenic Rupture of the Plantar Fascia: A Case Report.

Plantar fasciitis is a common cause of heel pain, and the disorder is generally self-limiting after adequate conservative treatment. When conservative treatment is unsuccessful, surgical release is an effective treatment option. Here we report a case of iatrogenic plantar fascia rupture after surgical release for treatment of recalcitrant plantar fasciitis. Preoperative MRI revealed a 4.2 cm gap between the distal fascia stump and the calcaneal tuberosity in the sagittal view at 8 months post-injury. To circumvent the possibility of rupture site retear or poor tissue healing by direct repair, we used tendon allografting for the reconstruction of the chronic plantar fascia rupture. The patient gradually recovered after the surgery. Complications of plantar fascia rupture after surgical release is a potential risk but rarely observed. Chronic plantar fascia rupture with medial arch collapse is difficult to treat. We used a tendon allograft to reconstruct the plantar fascia, restoring its function and mechanical strength. After 5 years of follow-up, no complications were reported, and magnetic resonance imaging indicated the reconstructed plantar fascia tissue to be in good condition.

Three-dimensional spherical gelatin bubble-based scaffold improves the myotube formation of H9c2 myoblasts.

Microenvironmental factors including physical and chemical cues can regulate stem cells as well as terminally differentiated cells to modulate their biological function and differentiation. However, one of the physical cues, the substrate's dimensionality, has not been studied extensively. In this study, the flow-focusing method with a microfluidic device was used to generate gelatin bubbles to fabricate highly ordered three-dimensional (3D) scaffolds. Rat H9c2 myoblasts were seeded into the 3D gelatin bubble-based scaffolds and compared to those grown on 2D gelatin-coating substrates to demonstrate the influences of spatial cues on cell behaviors. Relative to cells on the 2D substrates, the H9c2 myoblasts were featured by a good survival and normal mitochondrial activity but slower cell proliferation within the 3D scaffolds. The cortical actin filaments of H9c2 cells were localized close to the cell membrane when cultured on the 2D substrates, while the F-actins distributed uniformly and occupied most of the cell cytoplasm within the 3D scaffolds. H9c2 myoblasts fused as multinuclear myotubes within the 3D scaffolds without any induction but cells cultured on the 2D substrates had a relatively lower fusion index even differentiation medium was provided. Although there was no difference in actin α 1 and myosin heavy chain 1, H9c2 cells had a higher myogenin messenger RNA level in the 3D scaffolds than those of on the 2D substrates. This study reveals that the dimensionality influences differentiation and fusion of myoblasts.

The chondroprotective effect of diosmin on human articular chondrocytes under oxidative stress.

Excessive oxidative stress, which can amplify inflammatory responses, is involved in the pathologic progression of knee osteoarthritis. Diosmin is known to possess a variety of biological functions such as antiinflammatory and antioxidant activities. We therefore demonstrated the chondroprotective potentials of diosmin on human articular chondrocytes under oxidative stress. The cytotoxicity of diosmin (5, 10, 50, and 100 µM) to chondrocytes was first evaluated. Subsequently, the cells were treated with diosmin (5 and 10 µM) after hydrogen peroxide (H2 O2 ) exposure. We found that the cytotoxicity of diosmin occurred in a dose-dependent manner (10, 50, and 100 µM), and low-dose diosmin (5 µM) slightly impaired cell viability. Diosmin supplementations (5 and 10 µM) did not show beneficial effects on mitochondrial activity, cytotoxicity, proliferation, and survival and the cell senescence was ameliorated in H2 O2 -exposed chondrocytes. On the other hand, diosmin down-regulated the mRNA levels of iNOS, COX-2, IL-1ß, COL1A1, MMP-3, and MMP-9; up-regulated TIMP-1 and SOX9; and improved COL2A1 in chondrocytes under oxidative stresses. Furthermore, diosmin also regulated glutathione reductase and glutathione peroxidase of H2 O2 -exposed chondrocytes. In conclusion, diosmin displayed a remarkable antiinflammatory effect compared with the antioxidant capacity on human chondrocytes. Diosmin can maintain the homeostasis of extracellular matrix of articular cartilage.

The Effects of Different Dynamic Culture Systems on Cell Proliferation and Osteogenic Differentiation in Human Mesenchymal Stem Cells.

The culture environment plays an important role for stem cells' cultivation. Static or dynamic culture preserve differential potentials to affect human mesenchymal stem cells' (hMSCs) proliferation and differentiation. In this study, hMSCs were seeded on fiber disks and cultured in a bidirectional-flow bioreactor or spinner-flask bioreactor with a supplement of osteogenic medium. The hMSCs' proliferation, osteogenic differentiation, and extracellular matrix deposition of mineralization were demonstrated. The results showed that the spinner flask improved cell viability at the first two weeks while the bidirectional-flow reactor increased the cell proliferation of hMSCs through the four-week culture period. Despite the flow reactor having a higher cell number, a lower lactose/glucose ratio was noted, revealing that the bidirectional-flow bioreactor provides better oxygen accessibility to the cultured cells/disk construct. The changes of calcium ions in the medium, the depositions of Ca2+ in the cells/disk constructs, and alkaline phosphate/osteocalcin activities showed the static culture of hMSCs caused cells to mineralize faster than the other two bioreactors but without cell proliferation. Otherwise, cells were distributed uniformly with abundant extracellular matrix productions using the flow reactor. This reveals that the static and dynamic cultivations regulated the osteogenic process differently in hMSCs. The bidirectional-flow bioreactor can be used in the mass production and cultivation of hMSCs for applications in bone regenerative medicine.

Ultrasound-Guided Minimally Invasive Surgical Resection of Retrocalcaneal Bursitis: A Preliminary Comparison With Traditional Open Surgery.

Posterior heel pain is a common complaint that is often caused by overuse injuries. In such cases, the retrocalcaneal bursa is compressed and chafed repeatedly, leading to local inflammation. Sonography is a popular imaging tool used to study the pathology of soft tissues, and it can be used to assist in diagnosing bursitis because of its accuracy. Herein, we report an innovative method to treat retrocalcaneal bursitis under ultrasound guidance. Ten patients with posterior heel pain for >6 months who failed conservative treatment received this ultrasound-guided minimally invasive surgery. An endoscopic puncher and burr were inserted under ultrasound guidance via a stabbing wound, and the swollen retrocalcaneal bursa and bony prominence were resected. The patients were able to ambulate and undergo a rehabilitation program 2 weeks postoperatively. In the patients who underwent this ultrasound-guided minimally invasive surgery, both the average surgical time and average hospital stay were shorter than in those (n = 12) who underwent open surgery. In outcome rating assessment, the American Orthopaedic Foot & Ankle Society (AOFAS) pain score and total AOFAS ankle-hindfoot score were improved in the ultrasound-guided minimally invasive surgery group compared to the open surgery group at 2 months postoperatively. Other advantages included lesser wound pain, shorter hospital stay, faster recovery time, and minimal blood loss. Accordingly, ultrasound-guided surgery appears to be a good option for the treatment of retrocalcaneal bursitis.

Low-adhesive ethylene vinyl alcohol-based packaging to xenogeneic islet encapsulation for type 1 diabetes treatment.

Transplantation of encapsulated porcine islets is proposed to treat type 1 diabetes. However, the envelopment of fibrous tissue and the infiltration of immune cells impair islet function and eventually cause implant failure. It is known that hemodialysis using an ethylene vinyl alcohol (EVOH) membrane results in minor tissue responses. Therefore, we hypothesized that using a low-adhesive EVOH membrane for encapsulation may prevent host cell accumulation and fibrous capsule formation. In this study, rat islets suspended in chitosan gel were encapsulated in bags made from highly porous EVOH membranes, and their in vitro insulin secretion function as well as in vivo performance was evaluated. The results showed that the EVOH bag did not affect islet survival or glucose-stimulated insulin secretion. Whereas naked islets were dysfunctional after 7 days of culture in vitro, islets within the EVOH bag produced insulin continuously for 30 days. Streptozotocin-induced diabetic mice were given islets-chitosan gel-EVOH implants intraperitoneally (650-800 islets equivalent) and exhibited lower blood glucose levels and regained body weight during a 4-week observation period. The transplanted mice had higher levels of serum insulin and C-peptide, with an improved blood glucose disappearance rate. Retrieved implants had minor tissue adhesion, and histology showed a limited number of mononuclear cells and fibroblasts surrounding the implants. No invasion of host cells into the EVOH bags was noticed, and the encapsulated islets were intact and positive for insulin-glucagon immunostaining. In conclusion, an EVOH bag can protect encapsulated islets, limit fibrous capsule formation, and extend graft function.

An assessment of femoral rotational alignment of mini-incision total knee arthroplasty: A comparison based on the transepicondylar line from the kneeling view and the intraoperative posterior condylar line.

BACKGROUND: Rotational alignment of the distal femur is important in total knee arthroplasty. The purpose of this study is to use a roentgenographic technique to evaluate the accuracy of mini-incision total knee arthroplasty (MIS TKA) performed based on the transepicondylar line from the kneeling view. METHODS: Totally 32 patients (aged from 64 to 80 years with an average of 70.9 years) with 46 cases of knee osteoarthritis received MIS TKA were registered. Before surgery, the condylar twist angle was measured from the kneeling view. The bone cut for the external rotation was completed, with regard to the condylar twist angle. The control group including 26 patients (aged from 50 to 89 years with an average of 69.7 years) with 42 cases of knee osteoarthritis underwent TKA with built-in cutting jig design 3 degrees of femoral external rotation. This study is a prospective continuous-time duration analysis study. The level of evidence is IIc. RESULTS: The mean condylar twist angle was 5.1° in the experimental group and 5.4° in the control group. The mean postoperative angle between the clinical epicondylar axis and the posterior condylar line of the femoral component was 0.46°. The same postoperative angle of the built-in external rotation in the control group was 2.7°. The condylar twist angle was significantly more accurate than the built-in design. CONCLUSION: Our result substantiates that the kneeling view is practicable and reproducible as the cutting reference for femoral external rotation. The accuracy of the kneeling view shows that the epicondylar axis can be used in smaller wound surgery, such as MIS TKA. LEVEL OF EVIDENCE: Level IIc.

Long-Term Oral Toxicity and Anti-osteoporotic Effect of Sintered Dicalcium Pyrophosphate in Rat Model of Postmenopausal Osteoporosis.

Sintered dicalcium pyrophosphate (SDCP), a synthetic pyrophosphate analog, has shown potential for the management of osteoporosis. The long-term oral toxicity and anti-osteoporotic effect of SDCP in a postmenopausal osteoporosis rat model were evaluated in this study. SDCP was orally administered to bilateral ovariectomized (OVX) Wistar rats at a dose of 0.75 mg/kg daily for 24 weeks following by 2 weeks of observation. There were no abnormal findings in clinical signs of toxicity, food consumption, body weight, blood examination, necropsy, and histological inspection attributable to the ingestion of SDCP. The serum level of type I collagen fragments, a bone resorption marker, decreased in SDCP-treated rats, and the bone formation markers alkaline phosphatase, osteocalcin, and osteopontin significantly decreased. These findings indicate that the bone turnover rate decreased in SDCP-treated animals. Relative to OVX rats, the increase in serum tartrate-resistant acid phosphatase 5b level represents an increase in bony tissues in the SDCP-treated rats. Histological examinations of distal femoral metaphyses further revealed that the ingestion of SDCP improved the trabecular bone architecture and decreased bone porosity. Analysis of limb bone ashes showed a significant increase in bone mineral content. Our results show that SDCP inhibits bone resorption to restore bone mass in OVX rats without deleterious effects, and therefore that SDCP has potential in the management of osteoporosis.

Tooth Germ-Like Construct Transplantation for Whole-Tooth Regeneration: An In Vivo Study in the Miniature Pig.

The purpose of this study was to demonstrate the feasibility of whole-tooth regeneration using a tooth germ-like construct. Dental pulp from upper incisors, canines, premolars, and molars were extracted from sexually mature miniature pigs. Pulp tissues were cultured and expanded in vitro to obtain dental pulp stem cells (DPSCs), and cells were differentiated into odontoblasts and osteoblasts. Epithelial cells were isolated from gingival epithelium. The epithelial cells, odontoblasts, and osteoblasts were seeded onto the surface, upper, and lower layers, respectively, of a bioactive scaffold. The lower first and second molar tooth germs were removed bilaterally and the layered cell/scaffold constructs were transplanted to the mandibular alveolar socket of a pig. At 13.5 months postimplantation, seven of eight pigs developed two teeth with crown, root, and pulp structures. Enamel-like tissues, dentin, cementum, odontoblasts, and periodontal tissues were found upon histological inspection. The regenerated tooth expressed dentin matrix protein-1 and osteopontin. All pigs had regenerated molar teeth regardless of the original tooth used to procure the DPSCs. Pigs that had tooth germs removed or who received empty scaffolds did not develop teeth. Although periodontal ligaments were generated, ankylosis was found in some animals. This study revealed that implantation of a tooth germ-like structure generated a complete tooth with a high success rate. The implant location may influence the morphology of the regenerated tooth.

A biomimetic honeycomb-like scaffold prepared by flow-focusing technology for cartilage regeneration.

A tissue engineering chondrocytes/scaffold construct provides a promise to cartilage regeneration. The architecture of a scaffold such as interconnections, porosities, and pore sizes influences the fates of seeding cells including gene expression, survival, migration, proliferation, and differentiation thus may determine the success of this approach. Scaffolds of highly ordered and uniform structures are desirable to control cellular behaviors. In this study, a newly designed microfluidic device based on flow-focusing geometry was developed to fabricate gelatin scaffolds of ordered pores. In comparison with random foam scaffolds made by the conventional freeze-dried method, honeycomb-like scaffolds exhibit higher swelling ratio, porosity, and comparable compressive strength. In addition, chondrocytes grown in the honeycomb-like scaffolds had good cell viability, survival rate, glycosaminoglycans production, and a better proliferation than ones in freeze-dried scaffolds. Real-time PCR analysis showed that the mRNA expressions of aggrecan and collagen type II were up-regulated when chondrocytes cultured in honeycomb-like scaffolds rather than cells cultured as monolayer fashion. Oppositely, chondrocytes expressed collagen type II as monolayer culture when seeded in freeze-dried scaffolds. Histologic examinations revealed that cells produced proteoglycan and distributed uniformly in honeycomb-like scaffolds. Immunostaining showed protein expression of S-100 and collagen type II but negative for collagen type I and X, which represents the chondrocytes maintained normal phenotype. In conclusion, a highly ordered and honeycomb-like scaffold shows superior performance in cartilage tissue engineering. Biotechnol. Bioeng. 2014;111: 2338-2348. © 2014 Wiley Periodicals, Inc.

Current treatment concepts for Achilles tendon rupture.

Achilles tendon rupture is a common and primary cause of lower limb tendon injury suffered during sports-related activities. The causes of Achilles tendon rupture include the calf muscle and tendon overuse, poor tendon quality, and various medical conditions. Historically, acute Achilles tendon rupture was treated conservatively. However, historical techniques are now associated with an increased risk of rerupture. To address this problem, open repair has been proposed. Open repair is associated with a reduced risk of rerupture; however, it is also closely associated with wound complications, like wound infection, whose treatment is time-consuming and costly. Therefore, minimally invasive Achilles tendon repair has been proposed as a promising option with acceptable functional outcomes. Nevertheless, despite its benefits, minimally invasive Achilles tendon repair is associated with increased risks of sural nerve injury and rerupture. In this review, we evaluate the currently used treatment strategies for acute Achilles tendon rupture and their historical evolution to provide evidence-based recommendations for physicians.

Development and functional evaluation of a hyaluronic acid coated nano-formulation with kaempferol as a novel intra-articular agent for Knee Osteoarthritis treatment.

Knee osteoarthritis (OA) involves articular cartilage degradation driven mainly by inflammation. Kaempferol (KM), known for its anti-inflammatory property, holds potential for OA treatment. This study investigated the potential of hyaluronic acid (HA)-coated gelatin nanoparticles loaded with KM (HA-KM GNP) for treating knee OA. KM was encapsulated into gelatin nanoparticles (KM GNP) and then coated with HA to form HA-KM GNPs. Physical properties were characterized, and biocompatibility and cellular uptake were assessed in rat chondrocytes. Anti-inflammatory and chondrogenic properties were evaluated using IL-1ß-stimulated rat chondrocytes, compared with HA-coated nanoparticles without KM (HA GNP) and KM alone. Preclinical efficacy was tested in an anterior cruciate ligament transection (ACLT)-induced knee OA rat model treated with intra-articular injection of HA-KM GNP. Results show spherical HA-KM GNPs (88.62 ± 3.90 nm) with positive surface charge. Encapsulation efficiency was 98.34 % with a sustained release rate of 18 % over 48 h. Non-toxic KM concentration was 2.5 µg/mL. In IL-1ß-stimulated OA rat chondrocytes, HA-KM GNP significantly down-regulated RNA expression of IL-1ß, TNF-α, COX-2, MMP-9, and MMP-13, while up-regulating SOX9 compared to HA GNP, and KM. In vivo imaging demonstrated significantly higher fluorescence intensity within rat knee joints for 3 hours post HA-KM GNP injection compared with KM GNP (185.2% ± 34.1% vs. 45.0% ± 16.7%). HA-KM GNP demonstrated significant effectiveness in reducing subchondral sclerosis, attenuating inflammation, inhibiting matrix degradation, restoring cartilage thickness, and reducing the severity of OA in the ACLT rat model. In conclusion, HA-KM GNP holds promise for knee OA therapy.

Lovastatin impairs cellular proliferation and enhances hyaluronic acid production in fibroblast-like synoviocytes.

INTRODUCTION: Statins have demonstrated chondroprotective effects by reducing inflammation and mitigating extracellular matrix degradation. However, statins are also reported to be cytotoxic to several types of cells. Early-onset osteoarthritis (OA) is characterized by synovial inflammation, which adversely affects hyaluronan (HA) production in fibroblast-like synoviocytes (FLSs). Nevertheless, the precise effects of statins on the synovium remain unclear. METHODS: This study investigated the impact of lovastatin on human FLSs, and HA secretion-related genes, signaling pathways, and production were evaluated. RESULTS: The findings revealed that high doses of lovastatin (20 or 40 µM) decreased FLS viability and increased cell death. FLS proliferation ceased when cultured in a medium containing 5 or 10 µM lovastatin. mRNA expression analysis demonstrated that lovastatin (5 and 10 µM) upregulated the gene level of hyaluronan synthase 1 (HAS1), HAS2, and proteoglycan 4 (PRG4), but not HAS3. While the expression of multidrug resistance-associated protein 5 transporter gene remained unaffected, both inward-rectifying potassium channel and acid-sensing ion channel 3 were upregulated. Western blot further confirmed that lovastatin increased the production of HAS1 and PRG4, and activated the PKC-α, ERK1/2, and p38-MAPK signaling pathways. Additionally, lovastatin elevated intracellular cAMP levels and HA production in FLSs. CONCLUSION: Lovastatin impairs cellular proliferation but enhances HA production in human FLSs.

Comparison of Knot-Tying Techniques During the Arthroscopic Broström-Gould Procedure: Semiconstrained Freehand Versus Knot Pusher Techniques.

Background: The arthroscopic Broström technique with or without Gould modification has been used to treat patients with anterior talofibular ligament injury who failed nonoperative management and progressed to chronic lateral ankle instability. However, some patients develop limited range of motion over the ankle joint postoperatively. Purpose/Hypothesis: To compare the clinical outcomes and midterm functional performance of knot-tying techniques between using a knot pusher and a semiconstrained freehand tie during arthroscopic Broström-Gould procedure with inferior extensor retinaculum (IER) augmentation. It was hypothesized that the semiconstrained freehand tie would provide better plantarflexion of the ankle joint compared with the knot pusher. Study Design: Cohort study; Level of evidence, 3. Methods: Included were 135 consecutive patients with mild-to-moderate lateral ankle instability (mean age, 42.7 years; range, 16-78 years) who underwent an arthroscopic Broström-Gould procedure from March 1, 2016, to April 30, 2022. The patients were divided into 2 groups according to the tying technique used in the Gould modification: surgical tie using a knot pusher (KP group; n = 30) or a semiconstrained freehand tie (FT group; n = 105). Radiographic parameters and ultrasound dynamic testing were examined during the preoperative assessment. Preoperative and 2-year postoperative assessments comprised American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, visual analog scale for pain, and 12-Item Short Form Survey (SF-12) scores. Results: The 2 groups had no differences in age, sex, or severity distribution in the preoperative assessment. American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, visual analog scale pain, and SF-12 scores were significantly better at the postoperative evaluation (all P < .05) in both groups. No significant difference was noted between groups in outcome scores. In the KP group, however, 7 out of 30 patients (23.3%) developed ankle stiffness with tightness when performing plantarflexion movement. No patients in the FT group reported similar symptoms. Conclusion: For mild-to-moderate chronic lateral ankle instability, we propose an arthroscopic Broström procedure with the addition of IER augmentation using a semiconstrained freehand tie to avoid overtightening the IER. This ensures favorable patient satisfaction and clinical outcomes without limitation of plantarflexion of the ankle joint and avoids the possible complication of stiffness with plantarflexion.

An in vitro analysis of the hemostatic efficacy of fibrinogen precipitation with varied keratin fraction compositions.

In preclinical studies, human hair has demonstrated effective hemostatic properties, potentially attributed to keratin proteins facilitating rapid conversion of fibrinogen to fibrin during coagulation. However, the rational use of human hair keratin for hemostasis remains unclear, given its complex mixture of proteins with diverse molecular weights and structures, leading to variable hemostatic capacity. To optimize the rational utilization of human hair keratin for hemostasis, we investigated the effects of different keratin fractions on keratin-mediated fibrinogen precipitation using a fibrin generation assay. Our study focused on high molecular weight keratin intermediate filaments (KIFs) and lower molecular weight keratin-associated proteins (KAPs) combined in various ratios during the fibrin generation. Scanning electron microscope analysis of the precipitates revealed a filamentous pattern with a broad distribution of fiber diameters, likely due to the diversity of keratin mixtures involved. An equal proportion of KIFs and KAPs in the mixture yielded the most extensive precipitation of soluble fibrinogen in an in vitro study, potentially due to structure-induced exposure of active sites. However, all hair protein samples exhibited diverse catalytic behaviors compared to thrombin, highlighting the potential of utilizing specific hair fractions to develop hair protein-based hemostatic materials with optimized capacity.

An assessment of physical properties and the viability of osteoblast-like cells of cefazolin-impregnated calcium sulfate bone-void filler.

Calcium sulfate, an injectable and biodegradable bone-void filler, is widely used in orthopedic surgery. Based on clinical experience, bone-defect substitutes can also serve as vehicles for the delivery of drugs, for example, antibiotics, to prevent or to treat infections such as osteomyelitis. However, antibiotic additions change the characteristics of calcium sulfate cement. Moreover, high-dose antibiotics may also be toxic to bony tissues. Accordingly, cefazolin at varying weight ratios was added to calcium sulfate samples and characterized in vitro. The results revealed that cefazolin changed the hydration reaction and prolonged the initial setting times of calcium sulfate bone cement. For the crystalline structure identification, X-ray diffractometer revealed that cefazolin additive resulted in the decrease of peak intensity corresponding to calcium sulfate dihydrate which implying incomplete phase conversion of calcium sulfate hemihydrate. In addition, scanning electron microscope inspection exhibited cefazolin changed the morphology and size of the crystals greatly. A relatively higher amount of cefazolin additive caused a faster degradation and a lower compressive strength of calcium sulfate compared with those of uploaded samples. Furthermore, the extract of cefazolin-impregnated calcium sulfate impaired cell viability, and caused the death of osteoblast-like cells. The results of this study revealed that the cefazolin additives prolonged setting time, impaired mechanical strength, accelerated degradation, and caused cytotoxicity of the calcium sulfate bone-void filler. The aforementioned concerns should be considered during intra-operative applications.

Bioinspired collagen-gelatin-hyaluronic acid-chondroitin sulfate tetra-copolymer scaffold biomimicking native cartilage extracellular matrix facilitates chondrogenesis of human synovium-derived stem cells.

The microenvironment plays a crucial role in stem cell differentiation, and a scaffold that mimics native cartilaginous extracellular components can promote chondrogenesis. In this study, a collagen-gelatin-hyaluronic acid-chondroitin sulfate tetra-copolymer scaffold with composition and architecture similar to those of hyaline cartilage was fabricated using a microfluidic technique and compared with a pure gelatin scaffold. The newly designed biomimetic scaffold had a swelling ratio of 1278 % ± 270 %, a porosity of 77.68 % ± 11.70 %, a compressive strength of 1005 ± 174 KPa, and showed a good resilience against compression force. Synovium-derived stem cells (SDSCs) seeded into the tetra-copolymer scaffold attached to the scaffold firmly and exhibited good mitochondrial activity, high cell survival with a pronounced glycosaminoglycan production. SDSCs cultured on the tetra-copolymer scaffold with chondrogenic induction exhibited upregulated mRNA expression of COL2A1, ChM-1, Nrf2, TGF-ß1, and BMP-7. Ex vivo study revealed that the SDSC-tetra-copolymer scaffold regenerated cartilage-like tissue in SCID mice with abundant type II collagen and S-100 production. BMP7 and COL2A1 expression in the tetra-copolymer scaffold group was much higher than that in the gelatin scaffold group ex vivo. The tetra-copolymer scaffold thus exhibits strong chondrogenic capability and will facilitate cartilage tissue engineering.

In vitro studies of composite bone filler based on poly(propylene fumarate) and biphasic α-tricalcium phosphate/hydroxyapatite ceramic powder.

While many different filler materials have been applied in vertebral augmentation procedures, none is perfect in all biomechanical and biological characteristics. To minimize possible shortages, we synthesized a new biodegradable, injectable, and premixed composite made from poly(propylene fumarate) (PPF) and biphasic α-tricalcium phosphate (α-TCP)/hydroxyapatite (HAP) ceramics powder and evaluated the material properties of the compound in vitro. We mixed the PPF cross-linked by N-vinyl pyrrolidinone and biphasic α-TCP/HAP powder in different ratios with benzoyl peroxide as an initiator. The setting time and temperature were recorded, although they could be manipulated by modulating the concentrations of hydroquinone and N,N-dimethyl-p-toluidine. Degradation, cytocompatibility, mechanical properties, and radiopacity were analyzed after the composites were cured by a cylindrical shape. We also compared the study materials with poly(methyl methacrylate) (PMMA) and PPF with pure HAP particles. Results showed that lower temperature during curing process (38-44°C), sufficient initial mechanical compressive fracture strength (61.1±3.7MPa), and gradual degradation were observed in the newly developed bone filler. Radiopacity in Hounsfield units was similar to PMMA as determined by computed tomography scan. Both pH value variation and cytotoxicity were within biological tolerable limits based on the biocompatibility tests. Mixtures with 70% α-TCP/HAP powder were superior to other groups. This study indicated that a composite of PPF and biphasic α-TCP/HAP powder is a promising, premixed, injectable biodegradable filler and that a mixture containing 70% α-TCP/HAP exhibits the best properties.

Chronic Lateral Ankle Instability Treated With Tendon Allografting: A Preliminary Comparison of Arthroscopic and Open Anatomic Ligament Reconstruction.

Background: Roughly 30% of patients with chronic lateral ankle instability (CLAI) have long-lasting painful instability requiring surgical intervention. Ligament reconstruction with the traditional open method and using tendon allografts can provide sufficient mechanical stability for severe CLAI. Arthroscopic ligament reconstruction with tendon allograft has recently been introduced to treat CLAI. Purpose: In this study, we describe an arthroscopic ligament reconstruction procedure involving the use of the tendon allograft for patients with CLAI, and we compare the efficacy of this procedure with open ligament reconstruction with tendon allograft. Study Design: Cohort study; Level of evidence, 3. Methods: We enrolled 10 patients (4 men and 6 women) with CLAI (mean age, 37.3 years; range, 16-57 years) who underwent arthroscopic ligament reconstruction with tendon allografting between November 2017 and June 2019. The control group consisted of 10 patients who received open tendon allograft reconstruction. Preoperative and 2-year postoperative functional outcomes were evaluated using the American Orthopaedic Foot & Ankle Society ankle-hindfoot scale (AOFAS), Karlsson Ankle Functional Score (KAFS), pain visual analog scale (VAS), 12-Item Short Form Health Survey (SF-12), and Tegner activity score (TAS). Results: The mean operative time was 118 and 110 minutes in the arthroscopic and open groups, respectively. At 2-year follow-up, scores on the AOFAS improved significantly compared with preoperatively, from 71.3 to 96.4 (P = .006) in the arthroscopic group, and from 68.6 to 96.7 (P = .005) in the open group. The postoperative AOFAS, VAS, KAFS, and SF-12 scores did not differ significantly between the 2 groups; however, the TAS score was significantly higher in the arthroscopic reconstruction group compared with in the open group (7 vs 6.1, respectively; P = .01). Conclusion: Arthroscopic ligament reconstruction with tendon allografting resulted in sufficient ankle stability and no donor-site morbidity. This procedure can yield similar functional outcomes to open reconstruction technique and may be an option for the management of CLAI.