HWJMSC-EVs promote cartilage regeneration and repair via the ITGB1/TGF-ß/Smad2/3 axis mediated by microfractures.

The current first-line treatment for repairing cartilage defects in clinical practice is the creation of microfractures (MF) to stimulate the release of mesenchymal stem cells (MSCs); however, this method has many limitations. Recent studies have found that MSC-derived extracellular vesicles (MSC-EVs) play an important role in tissue regeneration. This study aimed to verify whether MSC-EVs promote cartilage damage repair mediated by MFs and to explore the repair mechanisms. In vitro experiments showed that human umbilical cord Wharton's jelly MSC-EVs (hWJMSC-EVs) promoted the vitality of chondrocytes and the proliferation and differentiation ability of bone marrow-derived MSCs. This was mainly because hWJMSC-EVs carry integrin beta-1 (ITGB1), and cartilage and bone marrow-derived MSCs overexpress ITGB1 after absorbing EVs, thereby activating the transforming growth factor-ß/Smad2/3 axis. In a rabbit knee joint model of osteochondral defect repair, the injection of different concentrations of hWJMSC-EVs into the joint cavity showed that a concentration of 50 µg/ml significantly improved the formation of transparent cartilage after MF surgery. Extraction of regenerated cartilage revealed that the changes in ITGB1, transforming growth factor-ß, and Smad2/3 were directly proportional to the repair of regenerated cartilage. In summary, this study showed that hWJMSC-EVs promoted cartilage repair after MF surgery.

Anatomy of the fetal membranes: insights from spinning disk confocal microscopy.

PURPOSE: The fetal membranes are essential for the maintenance of pregnancy, and their integrity until parturition is critical for both fetal and maternal health. Preterm premature rupture of the membranes (pPROM) is known to be an indicator of preterm birth, but the underlying architectural and mechanical changes that lead to fetal membrane failure are not yet fully understood. The aim of this study was to gain new insights into the anatomy of the fetal membrane and to establish a tissue processing and staining protocol suitable for future prospective cohort studies. METHODS: In this proof of principle study, we collected fetal membranes from women undergoing vaginal delivery or cesarean section. Small membrane sections were then fixed, stained for nucleic acids, actin, and collagen using fluorescent probes, and subsequently imaged in three dimensions using a spinning disk confocal microscope. RESULTS: Four fetal membranes of different types were successfully processed and imaged after establishing a suitable protocol. Cellular and nuclear outlines are clearly visible in all cases, especially in the uppermost membrane layer. Focal membrane (micro) fractures could be identified in several samples. CONCLUSION: The presented method proves to be well suited to determine whether and how the occurrence of membrane (micro) fractures and cellular jamming correlate with the timing of membrane rupture and the mode of delivery. In future measurements, this method could be combined with mechanical probing techniques to compare optical and mechanical sample information.

Treatment of knee cartilage by cultured stem cells and three dimensional scaffold: a phase I/IIa clinical trial.

PURPOSE: Damage of the knee cartilage is a common condition manifesting itself mainly by pain and/or swelling that may substantially reduce the quality of life while ultimately leading to osteoarthritis in affected patients. Here, we aimed to evaluate the safety and efficacy of cultured autologous bone marrow mesenchymal stem cells (BM-MSCs) attached to the 3D Chondrotissue® scaffold by autologous blood plasma coagulation (BiCure® ortho MSCp) in the treatment of knee cartilage defects. METHODS: The primary endpoint of this phase I/IIa clinical trial was to evaluate the safety of the treatment. The secondary objective was to determine the short-to-medium-term therapeutic outcomes by standardized scoring questionnaires including Lysholm Knee Scoring Scale (Lysholm score), Knee Injury and Osteoarthritis Outcome Score (KOOS), and pain Visual Analogue Scale (VAS) systems and imaging (X-ray and magnetic resonance imaging, MRI). A total of six patients were included and followed for 12 months after the surgery. RESULTS: BiCure® ortho MSCp was well tolerated with no adverse events associated with the investigational medicinal product. Significant improvements were observed in Lysholm scores and KOOS while X-ray showed no deterioration of the arthritis and MRI revealed a persistent filling of the chondral defects by the implant. CONCLUSION: Overall, our data demonstrate the safety of the tested investigational medicinal product. The function of the treated knee improved within one year after surgery in all enrolled patients. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: EudraCT No.: 2018-004,067-31; October 18 2018.

A prospective, single-center study following operative treatment for osteochondral lesions of the talus.

BACKGROUND: (1) To evaluate patient-reported outcomes and revision surgeries after various operative interventions for osteochondral lesions of the talus (OLT) in a prospective single center series over 10 years, and (2) to identify predicting factors related to subjective ankle status and quality of life pre- and postoperatively. METHODS: Ninety-nine patients underwent operative treatment due to primary or recurrent OLT, with an average follow up 3.5 (1.8) years. Treatment outcome was followed clinically (FAOS, EQ-5D, Tegner activity scale) and by pursuing any serious adverse events or graft failures. RESULTS: There were 80 responding patients (81%) for the study. The mean lesion size was 2.0 (1.1) cm2. All FAOS values increased from preoperative to final follow-up values (Symptoms 60-68, Pain 58-69, ADL 71-80, Sport 36-54, QoL 30-45). EQ-5D increased from 0.49 to 0.62, while Tegner activity scale change from 3.2 to 3.4. There were 19 (24%) serious adverse events recorded; 13 (16%) of them were graft-related. Graft survival rates were 100% at 1 year, 94% (males)/93% (females) at 2 years, and 77% (males)/47% (females) at 5 years. Female gender, higher BMI, and higher Kellgren-Lawrence ankle OA score were negative predictors for preoperative patient-reported ankle joint status. The foremost improvement after operative intervention was observed in patients with large osteochondral lesions without postoperative adverse events. CONCLUSION: Various operative interventions for OLT significantly improved patients' ankle status and quality of life. High graft survival rates were demonstrated over first two years, but notable decline was confirmed thereafter, especially in female patients.

Mid-Term Outcomes after Arthroscopic "Tear Completion Repair" of Partial Thickness Rotator Cuff Tears.

Background and Objectives: Different arthroscopic procedures are used for partial-thickness rotator cuff tears (PT-RCTs), but there is still no evidence on the superiority of one procedure over the other. The aim of this study was to evaluate the clinical outcomes and the rate of complications of a tear completion repair (TCR) technique. Materials and Methods: Patients who had undergone arthroscopic TCR technique for PT-RCTs with a follow-up of at least 2-years after surgery were included. The TCR technique involved the removal of the "critical zone" and creating microfractures to biologically support tendon healing. Functional outcomes were assessed prospectively by the Constant score (CS) and active and passive range of movement (ROM). Pain and patient satisfaction were measured using a visual analog scale (VAS). Complication rates were recorded, and tendon integrity was assessed with magnetic resonance imaging (MRI) or ultrasound performed at least 2-years after surgery. Results: Eighty-seven patients with a median age of 57 years were followed-up for a median of 5 years. The CS score improved from 53.5 preoperatively to 94.0 postoperatively (p < 0.001). Median VAS score decreased from 8.6 to 1.0 (p < 0.0001). Median patient satisfaction was 9.3. The overall complication rate was 14.9%. Conclusions: Patients with PT-RCTs of the supraspinatus tendon treated by the TCR technique with "critical zone" removal and biological stimulation by microfractures showed good functional results with excellent strength recovery, a high degree of patient satisfaction, and resolution of painful symptoms at mid-term follow-up.

Surgical Treatment of Bone Marrow Lesion Associated with Recurrent Plantar Fasciitis: A Case Report Describing an Innovative Technique Using Subchondroplasty®.

Plantar fasciitis is one of the most common chief complaints seen in the foot and ankle clinic. With a relatively benign course, most cases are self-limiting or amendable to conservative therapy; ~90% of all plantar fasciitis cases will respond to these methods. When conservative treatment and time fail, surgical intervention can be necessary to improve outcomes. We present a novel method using Subchondroplasty® (SCP®; Zimmer Holdings, Inc.; Warsaw, IN) and revision fasciotomy in a case in which initial fasciotomy had failed. After the patient had failed to improve, a worsening underlying bone marrow lesion was identified at the origin of the plantar fascia; thus, SCP® was used with repeat fasciotomy. SCP® involves injecting calcium phosphate into bone marrow lesions to stimulate long-term bone repair. At 10 months after SCP®, the patient remained pain free and had returned to running at the final follow-up examination. This surgical treatment should be considered as an adjunctive procedure for those patients with plantar fasciitis, identifiable bone marrow lesions on magnetic resonance imaging, and continued pain when other treatment modalities have failed.

[Cartilage regeneration surgery on the hip : What is feasible?] / Knorpelregenerative Eingriffe am Hüftgelenk : Was ist machbar?

Localized cartilage defects at the hip are mainly caused by pre-arthritic deformities, particularly by cam-type femoroacetabular impingement (FAI). Timely elimination of symptomatic deformities can prevent further progression such as cartilage defects. As the defects mostly occur in the anterolateral part of the acetabulum, they can be easily treated either by open surgery or by arthroscopy. To date the most effective methods of treatment are bone marrow stimulation, with or without a covering of biomaterials, and autologous chondrocyte transplantation. In selected cases, readaptation of the damaged cartilage can be attempted by biological procedures. In the present article, the findings reported in current studies on these procedures are summarized and discussed in detail. An outlook is given regarding possible future treatment concepts.

Intra-articular injection of ascorbic acid enhances microfracture-mediated cartilage repair.

Previous studies have confirmed that ascorbic acid (AA) can promote cartilage repair and improve cartilage differentiation in bone marrow mesenchymal stem cells. However, the use of microfracture (MFX) combined with AA to repair cartilage damage has not been studied. This study established a rabbit animal model and treated cartilage injury with different concentrations of AA combined with MFX. Macroscopic observations, histological analysis, immunohistochemical analysis and reverse transcription quantitative polymerase chain reaction analysis of TGF-ß, AKT/Nrf2, and VEGF mRNA expression were performed. The results showed that intra-articular injection of AA had a positive effect on cartilage repair mediated by microfractures. Moreover, 10 mg/ml AA was the most effective at promoting cartilage repair mediated by microfractures. Intra-articular injection of AA promoted the synthesis of type II collagen and the formation of glycosaminoglycans by downregulating the mRNA expression of TGF-ß and VEGF. In summary, this study confirmed that AA could promote cartilage repair after MFX surgery.

Effect of micro-fractures on gas flow behavior in coal for enhanced coal bed methane recovery and CO2 storage.

This study investigates the impact of micro-fractures on gas flow behavior in coal formations, specifically within the context of CO2-based Enhanced Coal Bed Methane Recovery (ECBMR). Employing comparative analysis, various gas flow models, including Unipore Diffusion Model (UDM), Bidispersed Diffusion Model (BDM), Fractal Fractional Diffusion Model (FFDM), Time-Dependent Diffusivity Model (TDDM), Anomalous Sub-Diffusion Model (ASM), and Free Gas Density Gradient Model (FGDGM), are evaluated for their efficacy in capturing the complexities. The study aims to provide insights into the accuracy and applicability of these models, considering the heterogeneity of coal seams and the influence of micro-fractures on gas flow dynamics. The major findings include the categorization of different gas flow models based on their applicability to CO2-based ECBMR. For instance, the study suggests utilizing BDM and FFDM models while considering the heterogeneity of coal seams. Similarly using the TDDM model for time dynamics of ECBMR will give higher accuracy. The article contributes to a deeper understanding of gas migration processes in coal, particularly in the context of ECBMR, with implications for optimizing recovery strategies and addressing challenges associated with micro-fracture-induced variations in gas flow behavior.

Rapid Recovery after Reparation of Full-Thickness Chondral Defects of the Knee with the Use of Hyaluronan (HA)-Based 3-D Scaffold.

Articular cartilage injuries are found in up to 60% of patients who undergo an arthroscopic knee procedure, and those that totally affect articular cartilage (grade IV) have limited regenerative capacity and extended time for recovery. 3-D scaffolds represent a novel solution to address this type of injury. Our purpose was to analyze the MRI findings and functional status of patients that underwent repair of chondral defects either by microfractures or Hyaluronan (HA) 3-D scaffolding. We conducted a retrospective study of patients with chondral defects. The outcomes analyzed in this study included anatomical changes evaluated by the Henderson score (based on MRI findings) at baseline, 6, and 12 months after surgery, and improvement in functionality evaluated by the Modified Cincinnati Knee Rating System (MCKRS) at baseline and 6 months after surgery. Clinical and demographic characteristics were similar for both groups. There was a statistically significant improvement in Henderson score for the 3-D scaffold-treated group at 6 months versus the microfracture group (p < 0.0001). Improvement in functionality, measured by the MCKRS, was more frequently found in the 3-D scaffold-treated group. In conclusion, the use of HA 3-D scaffolding was superior, with faster recovery evident 6 months after the surgery that progressed to full recovery in all patients a year after surgery. Future studies with a randomized design might help to support our findings. This study provides level III evidence.

Sport Activity and Clinical Outcomes after Hip Arthroscopy with Acetabular Microfractures at a Minimum 2-Year Follow-Up: A Matched-Pair Controlled Study.

Background: Acetabular microfractures for cartilage lesions have been shown to be a safe procedure able to improve patient reported outcomes (PROs). Nevertheless, the return to sport activity rate represents a crucial outcome to be investigated in these young athletic patients. Methods: Patients undergoing acetabular microfracture for full chondral acetabular lesions were compared to a 1:1 matched-pair by age and gender control group undergoing hip arthroscopy without microfractures. Clinical assessment was performed with PROs and participation in sports in terms of type and level of activities was evaluated preoperatively and at 2-years follow-up. Results: A total of 62 patients with an average age of 35.1 ± 8.1 (microfracture group) and 36.4 ± 6.3 (control group) were included. In both groups, the average values of PROs significantly increased from preoperatively to the last follow-up. There was no significant difference between the two groups in the number of patients playing at the amateur and elite level preoperatively and at the last follow-up. Conclusions: Microfractures for the management of full-thickness acetabular chondral defect provides good clinical results at a minimum follow-up of two years, which are not inferior to a matched-pair control group. Patients undergoing this procedure are likely able to return at the same level of sport before surgery.

Stress distribution around kerogen particles as a measure of the initiation of bitumen-filled microfractures in organic-rich source rocks.

In this article, we present a method used to model the initiation of bitumen-filled microfractures in immature, organic-rich source rocks. The first part presents the method used to calculate the stress distribution around the kerogen particles. The second part explains the method used to calculate the pressure change as a function of the transformation ratio and the resulting overpressure.•The effective principal stresses acting on the kerogen boundary were calculated.•Kerogen geometries were determined using the measured aspect ratio of the kerogen traces obtained from the petrography observation.•To estimate overpressure, the increase in pressure due to the transformation of kerogen to bitumen was calculated.

The Ankle Spacer-a hemiarthroplasty for treatment of severe osteochondral defects of the talus.

OBJECTIVE: The Ankle Spacer system has been developed as a joint-preserving option for patients with failed treatment of large talar osteochondral defects (OCDs). It is a one-piece implant system that replaces the articulating upper talus surface of the tibiotalar joint. INDICATIONS: Large OCDs with failed prior surgical intervention(s) and/or multiple talar OCDs on the talar surface, posttraumatic or degenerative osteoarthritis, or avascular necrosis of the talus. CONTRAINDICATIONS: Severe malalignment exceeding 7° and other ankle deformities that would not allow proper rasping of the talus, obesity, blood supply limitations, severe osteopenia, and previous or active infections. SURGICAL TECHNIQUE: The surgery is carried out via a central approach to the ankle joint. The tibiotalar joint was distracted to remove the cartilage on the upper talar surface with special talus rasps and to perform microfracture of the entire talar surface. The appropriate Ankle Spacer trial was then inserted into the joint and fluoroscopy was used to check for proper trial size and positioning. After thorough cleaning of the prepared bone bed, the Ankle Spacer was inserted with a special seating instrument. POSTOPERATIVE MANAGEMENT: One surgeon in our center implanted ten Ankle Spacers between April 2018 and October 2019. The first short-term data with follow-up of 3 months were collated. RESULTS: No implant-related complications were recorded. American Orthopaedic Foot and Ankle Society (AOFAS) score increased from 55.5 to 79.5 points, European Foot and Ankle Society (EFAS) score increased from 5.6 to 13.5 points, and pain score decreased from 3 to 1.1 points. None of the patients' radiographs showed signs of loosening or osteoarthritis progression.

A study on the morphology of natural microfractures in marine and continental transitional shale based on scanning electron microscopy image.

The development of natural microfractures not only directly affects exploitation efficiency of a shale gas reservoir, but also determines the quality and production of the shale gas reservoir. The environment, in which the shale forms, is considered to be the fundamental cause of shale pore formation and deformation. However, the traditional method of observing shale samples using field-emission scanning electron microscopy (FE-SEM) can be interfered by a large number of fractures caused by artificial damage on the shale surface during sample preparation, such as mechanical damage during polishing and shrinkage damage of shale mineral particles. To tackle this issue, we summarized the features of natural fractures by comparing fracture morphology of shale before and after artificial damage. In this study, the powder samples which suffered serious structural damage and the block samples with light structural damage were observed by FE-SEM. In addition, we used the pressure switch to cause slight damage to the surface of gold-plated block samples, and the difference between the gold film tearing edge and the mineral tearing edge was used to identify the artificial cracks generated during this process. We found (1) most of the open structural fractures on the shale surface are not natural, but artificially induced during the sample preparation process; (2) most non-structural natural fractures are mainly related to organic matter, clay and calcite; (3) stress and shrinkage are the main causes of natural microfractures; (4) natural microfractures in shale have a clear pressure support structure, which are categorized into self-supporting fractures.

Evaluation of surface changes of stainless steel miniplates and screws following retrieval from maxillofacial trauma and orthognathic surgery patients: A comparative study.

BACKGROUND: Metal implants have the potential to degrade body fluids. Corrosive degradation has been demonstrated in laboratory tests, both under simulated clinical conditions and by electrochemical methods, as well as in studies of retrieved metal implants. The clinical importance of degradation of metal implants is evidenced by particulate corrosion and wear products in tissue surrounding the implant, which may ultimately lead to bone loss. MATERIALS AND METHODS: The present study is to evaluate the surface changes such as corrosion, surface roughness, and microfractures and for the tensile strength of 18 stainless steel miniplates and 18 stainless steel screws which were used as rigid internal fixation in the management of maxillofacial fractures and orthognathic surgeries. RESULTS: In this study, surface roughness and microfractures were found in all the miniplates and screws that is 100%. Corrosion degradation was found in 12 of 18 plates that is 66.66%. CONCLUSION: Our results through scanning electron microscopy and stereo electron microscopy showed surface roughness, microfractures, and corrosion. However, tensile strength was not affected when the plates were in situ. Through our study, we recommend their retrieval after the purposes of rigid fixation have been fulfilled.

Management of Patellar Chondral Defects with Autologous Matrix Induced Chondrogenesis (AMIC) Compared to Microfractures: A Four Years Follow-Up Clinical Trial.

INTRODUCTION: Evidence on the management of chondral defects of the patella arises from studies in which the patellofemoral joint was treated together with the femorotibial joint and primary and revision settings. Furthermore, the superiority of Autologous Matrix Induced Chondrogenesis (AMIC) over microfractures (MFx) for patellar chondral defects is uncertain. Therefore, the present study compared primary isolated AMIC versus MFx for focal unipolar chondral defects of the patellar facet joints at midterm follow-up. METHODS: Patients undergoing AMIC or isolated MFx surgery for borderline-sized focal unipolar chondral defects of the patellar facet joints were followed at our institution. All surgeries were performed in the same fashion by experienced surgeons. A parapatellar arthrotomy was adopted in all surgeries. The outcomes of interest were: Visual Analogic Scale (VAS), Tegner Activity Scale, International Knee Documentation Committee (IKDC), and the Lysholm scores. The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) was assessed by a blinded radiologist, who had not been involved in the clinical management of the patients. RESULTS: 38 patients were enrolled in the present study: 27 underwent AMIC, and 11 MFx. The mean follow-up was 45.1 months. The mean age of the patients at baseline was 34.5 years. The mean size of the defect was 2.6 cm2. The MFx cohort experienced a shorter length of the hospitalization (P = 0.008). There was no difference in terms of follow-up and previous symptoms duration, mean age, sex, side, defect size, and BMI. At last follow-up, the AMIC cohort reported greater IKDC (P = 0.01), Lysholm (P = 0.009), and Tegner (P = 0.02), along with a low rate of failure (P = 0.02). VAS was lower in the AMIC group (P = 0.002). No difference was found in the MOCART score (P = 0.09), rates of revision (P = 0.06), and arthroplasty (P = 0.2). CONCLUSION: The AMIC procedure achieves greater IKDC and Lysholm score, and a significant reduction of the VAS score in the management of patellar chondral defects. The Tegner scale demonstrated greater activity after AMIC procedure. Finally, the AMIC group evidenced a lower rate of failure. Similarity was found on MOCART score, rates of revision, and arthroplasty between the two procedures.

Autologous Matrix Induced Chondrogenesis (AMIC) Compared to Microfractures for Chondral Defects of the Talar Shoulder: A Five-Year Follow-Up Prospective Cohort Study.

INTRODUCTION: Many procedures are available to manage cartilage defects of the talus, including microfracturing (MFx) and Autologous Matrix Induced Chondrogenesis (AMIC). Whether AMIC or MFx are equivalent for borderline sized defects of the talar shoulder is unclear. Thus, the present study compared the efficacy of primary isolated AMIC versus MFx for borderline sized focal unipolar chondral defects of the talar shoulder at midterm follow-up. METHODS: Patients undergoing primary isolated AMIC or MFx for focal unipolar borderline sized chondral defects of the talar shoulder were recruited prospectively. For those patients who underwent AMIC, a type I/III collagen resorbable membrane was used. The outcomes of interest were: Visual Analogic Scale (VAS), Tegner Activity Scale, American Orthopedic Foot and Ankle Score (AOFAS). The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) was assessed by a blinded radiologist, who had not been involved in the clinical management of the patients. Data concerning complication rate and additional procedures were also collected. RESULTS: The mean follow-up was 43.5 months. The mean age of the 70 patients at operation was 32.0 years, with a mean defect size of 2.7 cm2. The mean length of hospitalization was shorter in the MFx cohort (p = 0.01). No difference was found between the two cohorts in terms of length of prior surgery symptoms and follow-up, mean age and BMI, sex and side, and defect size. At a mean follow-up of 43.5 months, the AOFAS (p = 0.03), VAS (p = 0.003), and Tegner (p = 0.01) scores were greater in the AMIC group. No difference was found in the MOCART score (p = 0.08). The AMIC group evidenced lower rates of reoperation (p = 0.008) and failure (p = 0.003). CONCLUSION: At midterm follow-up, AMIC provides better results compared to MFx.

Influence of Micro-Pore Connectivity and Micro-Fractures on Calcium Leaching of Cement Pastes-A Coupled Simulation Approach.

A coupled numerical approach is used to evaluate the influence of pore connectivity and microcracks on leaching kinetics in fully saturated cement paste. The unique advantage of the numerical model is the ability to construct and evaluate a material with controlled properties, which is very difficult under experimental conditions. Our analysis is based on two virtual microstructures, which are different in terms of pore connectivity but the same in terms of porosity and the amount of solid phases. Numerical fracturing was performed on these microstructures. The non-fractured and fractured microstructures were both subjected to chemical leaching. Results show that despite very different material physical properties, for example, pore connectivity and effective diffusivity, the leaching kinetics remain the same as long as the amount of soluble phases, i.e., buffering capacity, is the same. The leaching kinetics also remains the same in the presence of microcracks.

Palaeopermeability anisotropy and geometrical properties of sealed-microfractures from micro-CT analyses: An open-source implementation.

Fault zone permeability and the real 3D-spatial distribution of the fault-related fracture networks are critical in the assessment of fault zones behavior for fluids. The study of the real 3D-spatial distribution of the microfracture network, using X-ray micro-computed tomography, is a crucial factor to unravel the real structural permeability conditions of a fault-zone. Despite the availability of several commercial software for rock properties estimation from X-ray micro-computed tomography scanning, their high cost and lack of programmability encourage the use of open-source data treatment. This work presents the implementation of a methodology flow for the quantification of both structural and geometrical parameters (fractures density, fractures aperture, fractures porosity, and fractures surface area), and the modeling of palaeopermeability of fault-related fractured samples, with focus in the proper spatial orientation of both the sample and the results. This is performed with an easy to follow step-by-step implementation, by a combination of open-source software, newly implemented codes, and numerical methods. This approach keeps track of the sample's spatial orientation from the physical to the virtual world, thus assessing any fault-related palaeopermeability anisotropy.

Microfractures and hydrogel scaffolds in the treatment of osteochondral knee defects: A clinical and histological evaluation.

BACKGROUND: Osteochondral knee defects (OCD) are often symptomatic, causing pain and functional impairment even in young and active patients. Regenerative surgical options, aiming to stimulate natural cartilage healing, have been recently used as a first line treatment. In this study, a new hydrogel is investigated in its capacity to regenerate the ultra-structural quality of hyaline cartilage when combined with a classical microfracture technique. MATERIAL AND METHODS: Forty-six patients, affected by grade III and IV knee chondropathies, were consecutively treated between 2013 and 2015 with microfractures followed by application of a modern hydrogel in the lesion site. All patients underwent clinical evaluation (WOMAC) pre-operatively, at 6,12 and at 24 months postoperatively: the results were compared with a subsequent, consecutive, matched, control group of 23 patients treated with microfractures alone. In a parallel and separate in-vitro histological study, adipose derived mesenchymal stem cells (ADMSCs) were encapsulated in the hydrogel scaffold, induced to differentiation into chondrocytes, and observed for a 3 weeks period. RESULTS: The initial WOMAC score of 58.6 ±â€¯11.0 in the study group was reduced by 88% at 6 months (7.1 ±â€¯9.2) and 95% at 24 months (2.9 ±â€¯5.9). The "in-vitro" study revealed a histological characterization typical of hyaline cartilage in study group. Separate biopsies performed at 12 months post-op in the study group also revealed type 2 collagen and hyaline-like cartilage in the regenerated tissue. CONCLUSION: Our study demonstrated high patient satisfaction rates after microfractures combined with a modern hydrogel scaffold; histologic evaluation supported the hypothesis of creating an enhanced chondrogenic environment. Microfracture "augmentation" using modern acellular biomaterials, like hydrogels, might improve the clinical outcomes of this classical bone marrow stimulating procedure.