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Objective: Knee osteoarthritis is the most common osteoarthritis and imposes a significant burden on patients' lives. Several treatment methods can promote cartilage repair to varying extents, but there are limited studies on the combined application of different treatments. The purpose of this study is to evaluate the clinical efficacy of microfracture combined with fibrinogen and platelet-rich plasma (PRP) under arthroscopic in treating knee osteoarthritis, so as to provide a basis for clinical treatment decisions. Method: A total of 113 patients with knee osteoarthritis who received orthopedic treatment from January 2021 to June 2022 were selected. They were divided into two groups according to whether they received fibrinogen and PRP treatment in addition to microfracture treatment. The two groups were analyzed to compare the differences in knee joint function and quality of life at different points. Results: The study compared changes in knee joint function scores and quality of life between the two groups after treatment and found that the quality of life of patients in the combined treatment group was significantly better than that of patients who received microfracture only (at 12-month follow-up, EuroQol-VAS scores were 64.32 ± 5.63 for the microfracture group (MFx) and 75.65 ± 8.57 for the fibrinogen combined with platelet-rich plasma-assisted microfracture group (FPRPA MFx); P = 0.015; at 24-month follow-up, EuroQol-VAS scores were 66.47 ± 5.18 for the MFx group and 79.40 ± 7.43 for the FPRPA MFx group, P = 0.022). There was also a strong correlation between patients' quality of life and knee joint function score index (IKDC score correlation coefficient r=-0.375, Lysholm score correlation coefficient r = 0.497, MOCART score correlation coefficient r = 0.579, VAS score correlation coefficient r = 0.242, T2 value correlation coefficient r=-0.293, P < 0.001). Age-stratified analysis of the patients in the microfracture combined with fibrinogen platelet-rich plasma treatment group showed that the effect of the combined treatment was more pronounced in elderly patients. Conclusions: The results of the study showed that compared with microfracture alone, microfracture combined with fibrinogen platelet-rich plasma therapy can further improve patients' knee joint-related function and their quality of life after treatment. The improvement was more obvious in elderly patients. [ABSTRACT FROM AUTHOR]

Background: This study aimed to compare the effects of microfracture (MF) versus intra-articular hyaluronic acid (HA) + oral glucosamine and chondroitin sulfate (GC) in addition to MF in patients with osteoarthritic knees who underwent medial open wedge high tibial osteotomy (MOWHTO) after an average follow-up of five years. Methods: The study was designed retrospectively and included patients who underwent MOWHTO due to gonarthrosis, the MF method performed on these patients, and HA + GC treatments applied in addition to MF. Three groups consisting of 79 patients were formed: only HTO (Group 1), HTO + MF (Group 2), and HTO + MF + HA + GC (Group 3). The groups were compared using knee injury and osteoarthritis outcome score (KOOS), visual analog scale (VAS) for pain, and range of motion (ROM). The associations between the degree of correction and function and pain were evaluated. Additionally, the KOOS subparameters were compared between the groups. Results: There were significant improvements in the postoperative KOOS and VAS scores in all three groups (p < 0.05). However, the ROM did not improve in Group 1. There was no significant difference in the postoperative KOOS, VAS, or ROM values ​​between Groups 2 and 3, but these values ​​were significantly better in Groups 2 and 3 than in Group 1 (p < 0.05). When the degree of correction increased, there were no significant positive changes in the postoperative KOOS or VAS score in Group 1, unlike in the other two groups (p < 0.05). In corrections of ≥ 10°, while there was no significant difference in the postoperative KOOS or VAS score ​​between Groups 2 and 3, these parameters significantly improved in these two groups compared to Group 1 (p < 0.05). Among the KOOS subparameters, pain and activities of daily living scores ​​were greater in Groups 2 and 3 than in Group 1 (p < 0.05). Conclusions: In MOWHTO, MF is a sufficient treatment method that improves the patient's clinical condition without requiring additional treatments such as HA and GC. Level of evidence: III, retrospective cohort study. [ABSTRACT FROM AUTHOR]

Treating cartilage damage is challenging as its ability for self-regeneration is limited. Left untreated, it can progress to osteoarthritis (OA), a joint disorder characterized by the deterioration of articular cartilage and other joint tissues. Surgical options, such as microfracture and cell/tissue transplantation, have shown promise as techniques to harness the body's endogenous regenerative capabilities to promote cartilage repair. Nonetheless, these techniques have been scrutinized due to reported inconsistencies in long-term outcomes and the tendency for the defects to regenerate as fibrocartilage instead of the smooth hyaline cartilage native to joint surfaces. Orthobiologics are medical therapies that utilize biologically derived substances to augment musculoskeletal healing. These treatments are rising in popularity because of their potential to enhance surgical standards of care. More recent developments in orthobiologics have focused on the role of exosomes in articular cartilage repair. Exosomes are nano-sized extracellular vesicles containing cargo such as proteins, lipids, and nucleic acids, and are known to facilitate intercellular communication, though their regenerative potential still needs to be fully understood. This review aims to demonstrate the advancements in cartilage regeneration, highlight surgical and biological treatment options, and discuss the recent strides in understanding the precise mechanisms of action involved. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to compare the early clinical and functional outcomes of two surgical interventions, microfracture and mosaicoplasty, in the treatment of medial talus osteochondral lesions (OCLs). Materials and Methods: This retrospective study included patients treated in the Department of Orthopaedics and Traumatology, Faculty of Medicine, Düzce University from January 2016 to January 2022. Patients were divided into two groups as those who underwent arthroscopic microfracture (Group 1, n=20) and those who underwent mosaicoplasty (Group 2, n=17). Preoperative and postoperative follow-up data were evaluated with visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) scores at baseline, 6 months and 12 months. Results: The mean age was 37.9±12.5 years in the microfracture group and 38±12.46 years in the mosaicoplasty group (p=0.981). Both groups showed significant improvement in VAS scores from baseline to the 6th and 12th months, and pain reduction was more significant in the mosaicoplasty group (p<0.001). AOFAS scores improved significantly in both groups and the mosaicoplasty group had better functional results at 12 months (p=0.069). Conclusions: Microfracture and mosaicoplasty are effective in the treatment of medial talus OCLs to reduce pain and improve clinical status in the early period. [ABSTRACT FROM AUTHOR]

Abstract Objective Knee osteoarthritis is the most common osteoarthritis and imposes a significant burden on patients’ lives. Several treatment methods can promote cartilage repair to varying extents, but there are limited studies on the combined application of different treatments. The purpose of this study is to evaluate the clinical efficacy of microfracture combined with fibrinogen and platelet-rich plasma (PRP) under arthroscopic in treating knee osteoarthritis, so as to provide a basis for clinical treatment decisions. Method A total of 113 patients with knee osteoarthritis who received orthopedic treatment from January 2021 to June 2022 were selected. They were divided into two groups according to whether they received fibrinogen and PRP treatment in addition to microfracture treatment. The two groups were analyzed to compare the differences in knee joint function and quality of life at different points. Results The study compared changes in knee joint function scores and quality of life between the two groups after treatment and found that the quality of life of patients in the combined treatment group was significantly better than that of patients who received microfracture only (at 12-month follow-up, EuroQol-VAS scores were 64.32 ± 5.63 for the microfracture group (MFx) and 75.65 ± 8.57 for the fibrinogen combined with platelet-rich plasma-assisted microfracture group (FPRPA MFx); P = 0.015; at 24-month follow-up, EuroQol-VAS scores were 66.47 ± 5.18 for the MFx group and 79.40 ± 7.43 for the FPRPA MFx group, P = 0.022). There was also a strong correlation between patients’ quality of life and knee joint function score index (IKDC score correlation coefficient r=-0.375, Lysholm score correlation coefficient r = 0.497, MOCART score correlation coefficient r = 0.579, VAS score correlation coefficient r = 0.242, T2 value correlation coefficient r=-0.293, P

Abstract Background This study aimed to compare the effects of microfracture (MF) versus intra-articular hyaluronic acid (HA) + oral glucosamine and chondroitin sulfate (GC) in addition to MF in patients with osteoarthritic knees who underwent medial open wedge high tibial osteotomy (MOWHTO) after an average follow-up of five years. Methods The study was designed retrospectively and included patients who underwent MOWHTO due to gonarthrosis, the MF method performed on these patients, and HA + GC treatments applied in addition to MF. Three groups consisting of 79 patients were formed: only HTO (Group 1), HTO + MF (Group 2), and HTO + MF + HA + GC (Group 3). The groups were compared using knee injury and osteoarthritis outcome score (KOOS), visual analog scale (VAS) for pain, and range of motion (ROM). The associations between the degree of correction and function and pain were evaluated. Additionally, the KOOS subparameters were compared between the groups. Results There were significant improvements in the postoperative KOOS and VAS scores in all three groups (p

Articular cartilage repair and regeneration is still a significant challenge despite years of research. Although microfracture techniques are commonly used in clinical practice, the newborn cartilage is usually fibrocartilage rather than hyaline cartilage, which is mainly attributed to the inadequate microenvironment for effectively recruiting, anchoring, and inducing bone marrow mesenchymal stem cells (BMSCs) to differentiate into hyaline cartilage. This paper introduces a novel cartilage acellular matrix (CACM) microgel assembly with excellent microporosity, injectability, tissue adhesion, BMSCs recruitment and chondrogenic differentiation capabilities to improve the microfracture-based articular cartilage regeneration. Specifically, the sustained release of simvastatin (SIM) from the SIM@CACM microgel assembly efficiently recruits BMSCs in the early stage of cartilage regeneration, while the abundant interconnected micropores and high specific area assure the quick adhesion, proliferation and infiltration of BMSCs. Additionally, the active factors within the CACM matrix, appropriate mechanical properties of the microgel assembly, and excellent tissue adhesion provide a conductive environment for the continuous chondrogenic differentiation of BMSCs into hyaline cartilage. Owing to the synergistic effect of the above-mentioned factors, good articular cartilage repair and regeneration is achieved.

At many quarries for the extraction of building stone there is a problem of increased output of fines after all stages of crushing and grinding, which leads to a decrease in the economic performance of mining enterprises. The fine fraction is formed by the crushing / grinding of prefractured rock mass. Reducing the intensity and size of the prefracture zones will lead to a solution to the problem at hand. To determine the effect of explosive detonation properties on the degree of structural weakening of a rock mass, studies were conducted to measure the detonation velocity, stresses generated by a blast in the rock mass, as well as laboratory studies of microfracturing by X-ray computer microtomography. The size of the prefracture zones increases from 33 to 77 charge radii with increasing the detonation velocity from 2 to 5.2 km/s. The dependence of the number of microdefects (microfractures) generated by a blast on the velocity of explosive detonation takes the form of an exponent for the near zone and is linear for the distances far from the blast. According to the data of the experiments conducted at short distances (10R), the density of induced microfracturing N is within ≈5 thousand pcs/cm3, and with increasing the detonation velocity it increases to ≈13.8 thousand pcs/cm3. At medium (40R) and long (70R) distances, N increases from ≈750 to ≈2,400 pcs/cm3 and from 0 to ≈200 pcs/cm3, respectively. Using explosives with a reduced detonation velocity allows reducing the “surplus” impact on a rock mass and thus reducing the intensity of prefracture in the zone of controlled crushing during a blast. The study allowed obtaining quantitative parameters of the intensity and size of the prefracture zones, which compose the supplement to findings of historical studies on qualitative determination of prefracture.

Abstract Dam stability is one of the most important issues in hydraulic engineering. Microfractures and damage commonly occur during impoundment, which might lead to serious dam problems. In this study, based on the engineering background of the Sanhekou hydropower station, microseismic monitoring and numerical simulation were employed to systematically investigate the microfracture and damage characteristics of the dam body. First, the microseismic monitoring system was established to capture the microfractures inside the dam. The results indicated that the rise in water level elevation has a significant effect on the microfracture and damage characteristics of the dam body, especially during the early stage of impoundment. This can be reflected by the variation in the derived source parameters, i.e., the b value, daily energy release, daily apparent stress and daily apparent volume. In addition, the failure mode of the microfractures could be determined by using the E S /E P value of microseismic events and the moment tensor inversion method. The cracking orientation of the failure surfaces could also be determined by the moment tensor inversion method. Subsequently, numerical simulation was conducted where the initial damage of the dam was considered by integrating the microseismic monitoring data. The simulation results suggested that dam deformation under impoundment considering microseismic feedback agrees well with the real field measured results. The stress level of the dam toe was larger than that of the dam heel, and both the dam toe and dam heel were under compression before impoundment. However, with increasing water level elevation, the stress status of the dam heel area changes from compression to tension. The findings in this study will provide a better understanding of the damage and failure mechanism of dams during impoundment, which might be helpful for the design and support of dams in hydropower stations.

Since the role of the menisci in knee stability, proprioception, and homeostasis has been well established, significant efforts have been made to repair meniscal tears, resulting in excellent clinical outcomes and a reduction in the progression of knee osteoarthritis (OA). However, varying failure rates have been reported, raising questions regarding the healing potential in cases of complex injuries, poorly vascularized and degenerated areas, and generally in the presence of unfavorable biological characteristics. Therefore, over the last few decades, different strategies have been described to increase the chances of meniscal healing. Biological augmentation of meniscal repair through various techniques represents a safe and effective strategy with proven clinical benefits. This approach could reduce the failure rate and expand the indications for meniscal repair. In the present study, we thoroughly reviewed the available evidence on meniscal repair surgery and summarized the main techniques that can be employed to enhance the biological healing potential of a meniscal lesion. Our aim was to provide an overview of the state of the art on meniscal repair and suggest the best techniques to reduce their failure rate. [ABSTRACT FROM AUTHOR]

PURPOSE OF THE STUDY In our study, it was aimed to evaluate the efficacy of microfracture and retrograde subchondral drilling on clinical outcomes in patients who underwent ankle arthroscopy due to osteochondral lesion of medial talus. MATERIAL AND M ETHODS Twenty eight patients with osteochondral lesion of talus less than 1.5 cm2 treated with ankle arthroscopy were evaluated retrospectively. Microfracture was performed in 16 patients and retrograde subchondral drilling was performed in 12 patients that there was no loss of integrity in the cartilage layer or cartilage layer is partially preserved during ankle arthroscopy. Postoperative evaluations of the patients were done with Foot and Ankle Ability Measure (FAAM) and results of both group were compared statistically. RESULTS The mean activities of daily living scale was 93.4±3.2 and sportive activity scale was 90.1±5.7 in the retrograde drilling group. In the micro-fracture group, mean activities of daily living scale was 93.8±4.1 and mean sportive activity scale was 88.9±9.5. No significant difference was found as a result of statistical comparisons of both groups results. DISCUSSION It has been determined that the size and preservation of the integrity of talar osteochondral lesions are important factors on clinical results. Results of arthroscopic debridement, microfracture and drilization are not good in lesions larger than 1.5 cm² and lesions with impaired integrity. In our study, depending on the general literature, osteochondral lesions in talus were less than 1.5 cm² in patients who underwent arthroscopic micro fracture and retrograde drilling. CONCLUSIONS Both microfracture and retrograde subchondral drilling are effective treatment methods with good clinical results for talar osteochondral lesions less than 1,5cm². Retrograde subchondral drilling can be an alternative treatment method with the reliability of clinical results in patients with no loss of the integrity of the cartilage layer or cartilage layer is partially preserved. [ABSTRACT FROM AUTHOR]

Introduction: Articular cartilage injuries of the knee are a complex and challenging clinical pathology. Objectives: The purpose of this study was to establish consensus statements via a Delphi process on bone marrow stimulation (BMS) for knee cartilage injuries. Methods: A consensus process on knee cartilage injuries utilizing a modified Delphi technique was conducted. Seventy-nine surgeons across 17 countries participated in these consensus statements. Fourteen questions were generated on BMS, with 3 rounds of questionnaires and final voting occurring. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was defined as 100% agreement with a proposed statement. Results: Of the 14 total questions and consensus statements on BMS developed from 3 rounds of voting, 0 achieved unanimous consensus, 3 achieved strong consensus, 4 achieved consensus, and 7 did not achieve consensus. Conclusions: The statements that achieved strong consensus related to lesion site preparation, ability to differentiate healthy/damaged cartilage, and distance between BMS holes. The statements that did not achieve consensus were primarily related to the indications for BMS, as well as the instrumentation and whether orthobiologics/scaffolds should be utilized.

Abstract Purpose This systematic review aimed to evaluate the effects of concurrent cartilage procedures on cartilage regeneration when performed alongside high tibial osteotomy (HTO). Materials and methods The systematic review followed the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). A comprehensive search was conducted on databases including PubMed, Embase, Cochrane Library, and Google Scholar, covering articles published until August 31, 2023. Results Sixteen studies (1277 patients) revealed that HTO, with or without concurrent cartilage procedures, leads to cartilage regeneration based on the International Cartilage Repair Society (ICRS) grade during second-look arthroscopy. No concurrent procedure showed improvement in ICRS grade (mean difference: − 0.80 to − 0.49). Microfracture (mean difference: − 0.75 to − 0.22), bone marrow aspirate concentrate (BMAC) (mean difference: − 1.37 to − 0.67), and human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) (mean difference: − 2.46 to − 1.81) procedures also demonstrated positive outcomes. Clinical outcome assessments for each cartilage procedure were also improved during postoperative follow-up, and no specific complications were reported. Conclusions HTO with or without concurrent cartilage procedures promotes cartilage regeneration observed during second-look arthroscopy, with improved clinical outcomes. Future randomized controlled trials on the same topic, along with subsequent meta-analyses, are necessary for conclusive findings.

Abstract The Pabdeh Formation represents organic matter enrichment in some oil fields, which can be considered a source rock. This study is based on the Rock–Eval, Iatroscan, and electron microscopy imaging results before and after heating the samples. We discovered this immature shale that undergoes burial and diagenesis, in which organic matter is converted into hydrocarbons. Primary migration is the process that transports hydrocarbons in the source rock. We investigated this phenomenon by developing a model that simulates hydrocarbon generation and fluid pressure during kerogen-to-hydrocarbon conversion. Microfractures initially formed at the tip/edge of kerogen and were filled with hydrocarbons, but as catagenesis progressed, the pressure caused by the volume increase of kerogen decreased due to hydrocarbon release. The transformation of solid kerogen into low-density bitumen/oil increased the pressure, leading to the development of damage zones in the source rock. The Pabdeh Formation’s small porethroats hindered effective expulsion, causing an increase in pore fluid pressure inside the initial microfractures. The stress accumulated due to hydrocarbon production, reaching the rock’s fracture strength, further contributed to damage zone development. During the expansion process, microfractures preferentially grew in low-strength pathways such as lithology changes, laminae boundaries, and pre-existing microfractures. When the porous pressure created by each kerogen overlapped, individual microfractures interconnected, forming a network of microfractures within the source rock. This research sheds light on the complex interplay between temperature, hydrocarbon generation, and the development of expulsion fractures in the Pabdeh Formation, providing valuable insights for understanding and optimizing hydrocarbon extraction in similar geological settings.

Water plugging by grouting in rock microfracture is a technical challenge in deep underground engineering. In this paper, a novel grouting test system was developed, which can simulate microfracture grouting tests under triaxial stress conditions. A specimen preparation method that can monitor the seepage and diffusion of microfine cement slurry in microfracture was also proposed. Microfracture grouting model tests were conducted on sandstone-like specimens to investigate the effects of confining pressure, roughness, and microfracture aperture on the seepage and diffusion characteristics of sandstone-like specimens. The test results show that microfine cement slurry can effectively seal the microfracture. However, when the microfracture aperture is small or the roughness is large, the slurry is easy to gather and deposit at the inlet, resulting in the phenomenon of ''seepage filtration'', which makes it difficult for the slurry to be injected into the microfracture. The pressure at the measuring point gradually decreases along the seepage and diffusion direction of the slurry, and the decreasing trend increases with the increase of microfracture roughness. The nonlinear relationship between the slurry volume flow rate and the hydraulic gradient can be described by Forchheimer's law. Moreover, both coefficients a and b in Forchheimer's equation show a gradual increase with increasing microfracture roughness. This study can provide a meaningful reference for the development of rock microfracture grouting technology in deep engineering.

Purpose: This systematic review aimed to evaluate the effects of concurrent cartilage procedures on cartilage regeneration when performed alongside high tibial osteotomy (HTO). Materials and methods: The systematic review followed the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). A comprehensive search was conducted on databases including PubMed, Embase, Cochrane Library, and Google Scholar, covering articles published until August 31, 2023. Results: Sixteen studies (1277 patients) revealed that HTO, with or without concurrent cartilage procedures, leads to cartilage regeneration based on the International Cartilage Repair Society (ICRS) grade during second-look arthroscopy. No concurrent procedure showed improvement in ICRS grade (mean difference: − 0.80 to − 0.49). Microfracture (mean difference: − 0.75 to − 0.22), bone marrow aspirate concentrate (BMAC) (mean difference: − 1.37 to − 0.67), and human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) (mean difference: − 2.46 to − 1.81) procedures also demonstrated positive outcomes. Clinical outcome assessments for each cartilage procedure were also improved during postoperative follow-up, and no specific complications were reported. Conclusions: HTO with or without concurrent cartilage procedures promotes cartilage regeneration observed during second-look arthroscopy, with improved clinical outcomes. Future randomized controlled trials on the same topic, along with subsequent meta-analyses, are necessary for conclusive findings. [ABSTRACT FROM AUTHOR]

The Pabdeh Formation represents organic matter enrichment in some oil fields, which can be considered a source rock. This study is based on the Rock–Eval, Iatroscan, and electron microscopy imaging results before and after heating the samples. We discovered this immature shale that undergoes burial and diagenesis, in which organic matter is converted into hydrocarbons. Primary migration is the process that transports hydrocarbons in the source rock. We investigated this phenomenon by developing a model that simulates hydrocarbon generation and fluid pressure during kerogen-to-hydrocarbon conversion. Microfractures initially formed at the tip/edge of kerogen and were filled with hydrocarbons, but as catagenesis progressed, the pressure caused by the volume increase of kerogen decreased due to hydrocarbon release. The transformation of solid kerogen into low-density bitumen/oil increased the pressure, leading to the development of damage zones in the source rock. The Pabdeh Formation's small porethroats hindered effective expulsion, causing an increase in pore fluid pressure inside the initial microfractures. The stress accumulated due to hydrocarbon production, reaching the rock's fracture strength, further contributed to damage zone development. During the expansion process, microfractures preferentially grew in low-strength pathways such as lithology changes, laminae boundaries, and pre-existing microfractures. When the porous pressure created by each kerogen overlapped, individual microfractures interconnected, forming a network of microfractures within the source rock. This research sheds light on the complex interplay between temperature, hydrocarbon generation, and the development of expulsion fractures in the Pabdeh Formation, providing valuable insights for understanding and optimizing hydrocarbon extraction in similar geological settings. [ABSTRACT FROM AUTHOR]

Osteochondral lesion of the talus (OLT) is a localized cartilage and subchondral bone injury of the talus trochlea. OLT is caused by trauma and other reasons, including osteochondritis dissecans of the talus (OCD) and talus osteochondral tangential fracture. OLT can develop from being asymptomatic to subchondral bone cysts accompanied by deep ankle pain. OLT tends to occur on the medial and lateral sides of the talar vault. OLT seriously affects the patients' life and work and may even lead to disability. Herein, we reviewed advances in the treatment of OLT and the strengths and weaknesses of various treatments. Different treatment methods, including conservative treatments and surgical treatments, can be adopted according to the different subtypes or clinical symptoms of OLT. Conservative treatments mostly relieve symptoms in the short term and only slow down the disease. In recent years, it has been discovered that platelet-rich plasma injection, microfracture, periosteal bone grafting, talar cartilage transplantation, allograft bone transplantation, reverse drilling under robotic navigation, and other methods can achieve considerable benefits when each of these treatment methods is applied. Furthermore, microfracture combined with platelet-rich plasma injections, microfracture combined with cartilage transplantation, and various other treatment methods combined with anterior talofibular ligament repair have all led to good treatment outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Cartilage lesions and osteoarthritis are very prevalent and imply a significant clinical and economic burden. Objectives: To review treatments for cartilage lesions in a time life sequence and its particularities. Methods: We performed a broad PUBMED database review with a sensitive systematized strategy without restriction to article date or type. Results: This review brings us to the aspects of chondral and osteochondral lesions throughout the different age groups of patients. Focusing mainly on surgical treatment, we present here the most widely used techniques. To facilitate discussion, patients have been divided into 3 groups: children and adolescents with open physes, adults until the fifth decade, and adult patients over the fifth decade. For open physes patients, their capacity for healing is of important consideration in both conservative and operative management. In those with closed physes, most patients are treated surgically. While marrow stimulation is the most common cartilage treatment procedure, there is a growing use of other techniques such as osteochondral autograft transplantation and osteochondral allograft transplantation. Patients over 50 years old commonly present with more severe chondral lesions, which influences the treatment decision-making process. Conclusion: When attempting to optimize cartilage restoration in these 3 groups, it is important to weigh the physiologic age, the extent of the cartilage lesion, and the stage of the degenerative and osteoarthritic processes.

Background: Advancements have been made in the realm of cartilage-regenerative techniques in the past decades. However, their comparative advantage has not yet been fully studied. Objectives: To comparatively analyze the functional, radiological and histological outcomes, and complications of various procedures available for the treatment of cartilage defects. Data sources: PubMed, Embase, Web of Science, Cochrane, and Scopus. Study eligibility criteria, participants, and interventions: Randomized controlled trials reporting functional, radiological, histological outcomes, or complications of various methods were utilized in the management of cartilage defects. Patients with cartilage defects. Treatment methods include microfracture (MFX), autologous chondrocyte implantation (ACI), osteochondral allograft/autograft transplantation (OAT), mosaicplasty, or acellular implants. Study appraisal and synthesis methods: Cochrane’s Confidence in Network meta-analysis approach. Network meta-analysis was conducted in Stata. Random effects model was used for forest plots. Results: Three thousand one hundred ninety-three patients from 54 randomized controlled trials were included in the analysis. The mean age of included patients was 37.9 (±9.46) years. MFX-I was used as a constant comparator. Among the restorative methods, OAT-II offered significantly better functional outcome at 5 years (weighted mean difference [WMD] = 16.00, 95% confidence interval [CI] [11.66, 20.34], P

The field data of shale fracturing demonstrate that the flowback performance of fracturing fluid is different from that of conventional reservoirs, where the flowback rate of shale fracturing fluid is lower than that of conventional reservoirs. At the early stage of flowback, there is no single-phase flow of the liquid phase in shale, but rather a gas-water two-phase flow, such that the single-phase flow model for tight oil and gas reservoirs is not applicable. In this study, pores and microfractures are extracted based on the experimental results of computed tomography (CT) scanning, and a spatial model of microfractures is established. Then, the influence of rough microfracture surfaces on the flow is corrected using the modified cubic law, which was modified by introducing the average deviation of the microfracture height as a roughness factor to consider the influence of microfracture surface roughness. The flow in the fracture network is simulated using the modified cubic law and the lattice Boltzmann method (LBM). The results obtained demonstrate that most of the fracturing fluid is retained in the shale microfractures, which explains the low fracturing fluid flowback rate in shale hydraulic fracturing.

Background: The utilization of decellularized extracellular matrix has gained considerable attention across numerous areas in regenerative research. Of particular interest is the human articular cartilage-derived extracellular matrix (hACECM), which presents as a promising facilitator for cartilage regeneration. Concurrently, the microfracture (MF) ​technique, a well-established marrow stimulation method, has proven efficacious in the repair of cartilage defects. However, as of the current literature review, no investigations have explored the potential of a combined application of hACECM and the microfracture technique in the repair of cartilage defects within a sheep model. Hypothesis: The combination of hACECM scaffold and microfracture will result in improved repair of full-thickness femoral condyle articular cartilage defects compared to the use of either technique alone. Study design: Controlled laboratory study. Methods: Full-thickness femoral condyle articular cartilage defect (diameter, 7.0 ​mm; debrided down to the subchondral bone plate) were created in the weight-bearing area of the femoral medial and lateral condyles (n ​= ​24). All of defected sheep were randomly divided into four groups: control, microfracture, hACECM scaffold, and hACECM scaffold ​+ ​microfracture. After 3, 6 and 12 months, the chondral repair was assessed for standardized (semi-) quantitative macroscopic, imaging, histological, immunohistochemical, mechanics, and biochemical analyses in each group. Result: At 3, 6 and 12 months after implantation, the gross view and pathological staining of regenerative tissues were better in the hACECM scaffold and hACECM scaffold ​+ ​microfracture groups than in the microfracture and control groups; Micro-CT result showed that the parameters about the calcified layer of cartilage and subchondral bone were better in the hACECM scaffold and hACECM scaffold ​+ ​microfracture groups than the others, and excessive subchondral bone proliferation in the microfracture group. The results demonstrate that human cartilage extracellular matrix scaffold alone is an efficient, safe and simple way to repair cartilage defects. Conclusion: hACECM scaffolds combined with/without microfracture facilitate chondral defect repair. The translational potential of this article: Preclinical large animal models represent an important adjunct and surrogate for studies on articular cartilage repair, while the sheep stifle joint reflects many key features of the human knee and are therefore optimal experimental model for future clinical application in human. In this study, we developed a human articular cartilage-derived extracellular matrix scaffold and to verify the viability of its use in sheep animal models. Clinical studies are warranted to further quantify the effects of hACECM scaffolds in similar settings.

Considering the action mechanisms of overpressure on physical changes in skeletal grains of deep reservoir rocks and the differences in physical changes of skeletal grains under overpressure and hydrostatic pressure, the sandstone of the Jurassic Toutunhe Formation in the southern margin of Junggar Basin was taken as an example for physical modeling experiment to analyze the action mechanisms of overpressure on the physical properties of deep reservoirs. (1) In the simulated ultra-deep layer with a burial depth of 6000–8000 m, the mechanical compaction under overpressure reduces the remaining primary pores by about a half that under hydrostatic pressure. Overpressure can effectively suppress the mechanical compaction to allow the preservation of intergranular primary pores. (2) The linear contact length ratio under overpressure is always smaller than the linear contact length ratio under hydrostatic pressure at the same depth. In deep reservoirs, the difference between the mechanical compaction degree under overpressure and hydrostatic pressure shows a decreasing trend, the effect of abnormally high pressure to resist the increase of effective stress is weakened, and the degree of mechanical compaction is gradually close to that under hydrostatic pressure. (3) The microfractures in skeletal grains of deep reservoirs under overpressure are thin and long, while the microfractures in skeletal grains of deep reservoirs under hydrostatic pressure are short and wide. This difference is attributed to the probable presence of tension fractures in the rocks containing abnormally high pressure fluid. (4) The microfractures in skeletal grains under overpressure were mainly formed later than that under hydrostatic pressure, and the development degree and length of microfractures both extend deeper. (5) The development stages of microfractures under overpressure are mainly controlled by the development stages of abnormally high pressure and the magnitude of effective stress acting on the skeletal grains. Moreover, the development stages of microfractures in skeletal grains are more than those under hydrostatic pressure in deep reservoir. The multi-stage abnormally high pressure plays an important role in improving the physical properties of deep reservoirs.

Treating cartilage damage is challenging as its ability for self-regeneration is limited. Left untreated, it can progress to osteoarthritis (OA), a joint disorder characterized by the deterioration of articular cartilage and other joint tissues. Surgical options, such as microfracture and cell/tissue transplantation, have shown promise as techniques to harness the body’s endogenous regenerative capabilities to promote cartilage repair. Nonetheless, these techniques have been scrutinized due to reported inconsistencies in long-term outcomes and the tendency for the defects to regenerate as fibrocartilage instead of the smooth hyaline cartilage native to joint surfaces. Orthobiologics are medical therapies that utilize biologically derived substances to augment musculoskeletal healing. These treatments are rising in popularity because of their potential to enhance surgical standards of care. More recent developments in orthobiologics have focused on the role of exosomes in articular cartilage repair. Exosomes are nano-sized extracellular vesicles containing cargo such as proteins, lipids, and nucleic acids, and are known to facilitate intercellular communication, though their regenerative potential still needs to be fully understood. This review aims to demonstrate the advancements in cartilage regeneration, highlight surgical and biological treatment options, and discuss the recent strides in understanding the precise mechanisms of action involved.

Fatigue fractures in materials are the main cause of approximately 80% of all material failures, and it is believed that such failures can be predicted and mathematically calculated in a reliable manner. It is possible to establish prediction modalities in cases of fatigue fractures according to three fundamental variables in fatigue, such as volume, number of fracture cycles, as well as applied stress, with the integration of Weibull constants (length characteristic). In this investigation, mechanical fatigue tests were carried out on specimens smaller than 4 mm2, made of different industrial materials. Their subsequent analysis was performed through precision computed tomography, in search for microfractures. The measurement of these microfractures, along with their metrics and classifications, was recorded. A convolutional neural network trained with deep learning was used to achieve the detection of microfractures in image processing. The detection of microfractures in images with resolutions of 480 × 854 or 960 × 960 pixels is the primary objective of this network, and its accuracy is above 95%. Images that have microfractures and those without are classified using the network. Subsequently, by means of image processing, the microfracture is isolated. Finally, the images containing this feature are interpreted using image processing to obtain their area, perimeter, characteristic length, circularity, orientation, and microfracture-type metrics. All values are obtained in pixels and converted to metric units (μm) through a conversion factor based on image resolution. The growth of microfractures will be used to define trends in the development of fatigue fractures through the studies presented. [ABSTRACT FROM AUTHOR]

Background: The most used treatment modality for chondral lesions of the patella, particularly when the lesion is <2 cm2, is microdrilling. However, reduced working space and mobility of the patella make this procedure technically difficult. To bypass this technical difficulty, we describe a simple technique of "Push and park" for microdrilling of the chondral lesions of the patella. Materials and Methods: Patients operated on by this technique in 2021 were followed for 1 year. Patients operated for magnetic resonance imaging-proven International Cartilage Repair Society grade III and IV patellofemoral chondral lesions (PFCLs) that are localized and <2 cm2 with or without other concomitant knee pathologies were included. The functional outcomes were evaluated using the Tegner Lysholm score and Kujala score. Results: Twenty-one patients were included in the study. Of these, 7 cases had isolated PFCL, 8 cases had associated medial meniscal posterior horn root tears, and the remaining 6 cases had anterior cruciate ligament injuries. The mean follow-up period was 14 (±2) months. The average age was 41 (±7) years. We had 12 female and 9 male patients. The Tegner Lysholm and Kujala scores improved significantly in all the patients at 1-year postsurgery (P = 0.035 and P = 0.026, respectively). Conclusion: We have described a simple and reproducible technique for microdrilling of difficult-to-access patellar lesions. When used appropriately, the technique can be a cost-effective method of managing the chondral lesions of the patella. [ABSTRACT FROM AUTHOR]

Considering the action mechanisms of overpressure on physical changes in skeletal grains of deep reservoir rocks and the differences in physical changes of skeletal grains under overpressure and hydrostatic pressure, the sandstone of the Jurassic Toutunhe Formation in the southern margin of Junggar Basin was taken as an example for physical modeling experiment to analyze the action mechanisms of overpressure on the physical properties of deep reservoirs. (1) In the simulated ultra-deep layer with a burial depth of 6000–8000 m, the mechanical compaction under overpressure reduces the remaining primary pores by about a half that under hydrostatic pressure. Overpressure can effectively suppress the mechanical compaction to allow the preservation of intergranular primary pores. (2) The linear contact length ratio under overpressure is always smaller than the linear contact length ratio under hydrostatic pressure at the same depth. In deep reservoirs, the difference between the mechanical compaction degree under overpressure and hydrostatic pressure shows a decreasing trend, the effect of abnormally high pressure to resist the increase of effective stress is weakened, and the degree of mechanical compaction is gradually close to that under hydrostatic pressure. (3) The microfractures in skeletal grains of deep reservoirs under overpressure are thin and long, while the microfractures in skeletal grains of deep reservoirs under hydrostatic pressure are short and wide. This difference is attributed to the probable presence of tension fractures in the rocks containing abnormally high pressure fluid. (4) The microfractures in skeletal grains under overpressure were mainly formed later than that under hydrostatic pressure, and the development degree and length of microfractures both extend deeper. (5) The development stages of microfractures under overpressure are mainly controlled by the development stages of abnormally high pressure and the magnitude of effective stress acting on the skeletal grains. Moreover, the development stages of microfractures in skeletal grains are more than those under hydrostatic pressure in deep reservoir. The multi-stage abnormally high pressure plays an important role in improving the physical properties of deep reservoirs. [ABSTRACT FROM AUTHOR]

Articular cartilage lacks natural healing abilities and necessitates surgical treatments for injuries. While microfracture (MF) is a primary surgical approach, it often results in the formation of unstable fibrocartilage. Delivering hyaline cartilage directly to defects poses challenges due to the limited availability of autologous cartilage and difficulties associated with allogeneic cartilage delivery. We developed a decellularized allogeneic cartilage paste (DACP) using human costal cartilage mixed with a crosslinked hyaluronic acid (HA)-carboxymethyl cellulose (CMC) carrier. The decellularized allogeneic cartilage preserved the extracellular matrix and the nanostructure of native hyaline cartilage. The crosslinked HA-CMC carrier provided shape retention and moldability. In vitro studies confirmed that DACP did not cause cytotoxicity and promoted migration, proliferation, and chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells. After 6 months of implantation in rabbit knee osteochondral defects, DACP combined with MF outperformed MF alone, demonstrating improved gait performance, defect filling, morphology, extracellular matrix deposition, and biomechanical properties similar to native cartilage. Thus, DACP offers a safe and effective method for articular cartilage repair, representing a promising augmentation to MF. Directly delivering hyaline cartilage to repair articular cartilage defects is an ideal treatment. However, current allogeneic cartilage products face delivery challenges. In this study, we developed a decellularized allogeneic cartilage paste (DACP) by mixing human costal cartilage with crosslinked hyaluronic acid (HA)-carboxymethyl cellulose (CMC). DACP preserves extracellular matrix components and nanostructures similar to native cartilage, with HA-CMC ensuring shape retention and moldability. Our study demonstrates improved cartilage repair by combining DACP with microfracture, compared to microfracture alone, in rabbit knee defects over 6 months. This is the first report showing better articular cartilage repair using decellularized allogeneic cartilage with microfracture, without the need for exogenous cells or bioactive substances. [Display omitted] [ABSTRACT FROM AUTHOR]

In view of the failure problem of sun gear splines in fan gearboxes, through the analysis of the chemical composition, microstructure, microfracture and mechanical properties of the failure spline, the cause of the spline wear is found out. The results show that there are more rods, unequal axes or islands of the undissolved ferrite in the metallographic structure of inter mediate shaft（IMS） sun gear motor side splines, which reduces the wear resistance of the material. The failure of sun gear splines is mainly caused by low tooth surface hardness. At the same time, due to the comprehensive action of fatigue wear, chemical corrosion, abrasive wear and other wear mechanisms, serious tooth surface wear occurs, resulting in a decrease of the bearing capacity of IMS sun gear motor side splines. The force transmission is not smooth, and the vibration is aggravated during operation, resulting in the failure of the gearbox. The test results can provide some theoretical guidance for the fault detection and diagnosis of wind power gearboxes.

Background: The primary aim of this study was to evaluate mid- and long-term outcomes following microfracture in patients with glenohumeral chondral lesions. Methods: This prospective cohort study assessed patients with shoulder pain who were treated with arthroscopic microfracture for full-thickness chondral lesions of the glenohumeral joint. Outcomes included the Simple Shoulder Test at baseline, mid-term (approximately 1 year) and long-term (approximately 10 years), and the Oxford Shoulder Score, shoulder pain (0-10 numerical scale) and radiological assessment using a modified Samilson & Prieto score at long-term follow-up. Data were analyzed with paired t-tests and Wilcoxon’s signed rank tests, which were considered significant if P

Abstract Articular cartilage injuries are common and lead to early joint deterioration and osteoarthritis. Articular cartilage repair techniques aim at forming a cartilaginous neo-tissue to support the articular load and prevent progressive degeneration. Several techniques are available for this purpose, such as microfracture and chondrocyte transplantation. However, the procedural outcome is often fibrocartilage, which does not have the same mechanical resistance as cartilaginous tissue. Procedures with autologous osteochondral graft have a morbidity risk, and tissue availability limits their use. As such, larger lesions undergo osteochondral transplantation using fresh or frozen grafts. New techniques using minced or particulate cartilage fragments or mesenchymal stem cells are promising. This paper aims to update the procedures for treating chondral lesions of the knee.

OBJECTIVE: The purpose of this study was to describe the current practice trends for managing symptomatic cartilage lesions of the knee with microfracture among ICRS (International Cartilage Regeneration & Joint Repair Society) members. DESIGN: A 42-item electronic questionnaire was sent to all ICRS members, which explored indications, surgical technique, postoperative management, and outcomes of the microfracture procedure for the treatment of symptomatic, full thickness chondral and osteochondral defects of the knee. Responses were compared between surgeons from different regions and years of practice. RESULTS: A total of 385 surgeons answered the questionnaire. There was a significant difference noted in the use of microfracture among surgeons by region (P < 0.001). There was no association between the number of years in practice and the self-reported proportion of microfracture cases performed (P = 0.37). Fifty-eight subjects (15%) indicated that they do not perform microfracture at all. Regarding indication for surgery, 56% of surgeons would limit their indication of microfracture to lesions measuring 2 cm2 or less. Half of the surgeons reported no upper age or body mass index limit. Regarding surgical technique, 90% of surgeons would recommend a formal debridement of the calcified layer and 91% believe it is important to create stable vertical walls. Overall, 47% of surgeons use biologic augmentation, with no significant difference between regions (P = 0.35) or years of practice (P = 0.67). Rehabilitation protocols varied widely among surgeons. CONCLUSIONS: Indications, operative technique, and rehabilitation protocols utilized for patients undergoing microfracture procedures vary widely among ICRS members. Regional differences and resources likely contribute to these practice pattern variations.

OBJECTIVE: The purpose of this study was to compare the results of a biphasic synthetic scaffold (TruFit, Smith & Nephew) to microfracture for the treatment of knee cartilage defects and identify patient- and lesion-specific factors that influence outcomes. DESIGN: Prospectively collected data from 132 patients (mean age, 41.8 years; 69% male) with isolated chondral or osteochondral femoral defects treated with biphasic synthetic scaffolds (n = 66) or microfracture (n = 66) were reviewed. Clinical outcomes were evaluated longitudinally over 5 years with the Short Form-36 (SF-36), Activities of Daily Living of the Knee Outcome Survey (KOS-ADL), International Knee Documentation Committee (IKDC), and Marx Activity Scale. Cartilage-sensitive magnetic resonance imaging (MRI) was performed to evaluate osseous integration and cartilage fill in a subgroup of patients. Multivariate regression analysis was used to identify predictors of clinical outcomes within the scaffold group. RESULTS: Both groups demonstrated clinically significant improvements in knee clinical scores over 5 years (P < 0.01). There were no significant differences in KOS-ADL and IKDC scores between groups up to 5 years postoperatively. Marx activity level scores in the microfracture group declined over time, while significant improvements in activity level scores were observed in the scaffold group over 5 years (P < 0.01). Good-quality tissue fill and cartilage isointensity were more often observed in the scaffold group compared with the microfracture group, particularly with longer time intervals. Increasing age, high body mass index, prior microfracture, and traumatic etiology were predictors for inferior outcomes in the scaffold group. CONCLUSIONS: Activity level and MRI appearance following treatment of cartilage lesions with the biphasic synthetic scaffold were superior to microfracture over time in this nonrandomized, retrospective comparison.

ObjectiveThe purpose of this study was to compare the results of a biphasic synthetic scaffold (TruFit, Smith & Nephew) to microfracture for the treatment of knee cartilage defects and identify patient- and lesion-specific factors that influence outcomes.DesignProspectively collected data from 132 patients (mean age, 41.8 years; 69% male) with isolated chondral or osteochondral femoral defects treated with biphasic synthetic scaffolds (n = 66) or microfracture (n = 66) were reviewed. Clinical outcomes were evaluated longitudinally over 5 years with the Short Form-36 (SF-36), Activities of Daily Living of the Knee Outcome Survey (KOS-ADL), International Knee Documentation Committee (IKDC), and Marx Activity Scale. Cartilage-sensitive magnetic resonance imaging (MRI) was performed to evaluate osseous integration and cartilage fill in a subgroup of patients. Multivariate regression analysis was used to identify predictors of clinical outcomes within the scaffold group.ResultsBoth groups demonstrated clinically significant improvements in knee clinical scores over 5 years (P < 0.01). There were no significant differences in KOS-ADL and IKDC scores between groups up to 5 years postoperatively. Marx activity level scores in the microfracture group declined over time, while significant improvements in activity level scores were observed in the scaffold group over 5 years (P < 0.01). Good-quality tissue fill and cartilage isointensity were more often observed in the scaffold group compared with the microfracture group, particularly with longer time intervals. Increasing age, high body mass index, prior microfracture, and traumatic etiology were predictors for inferior outcomes in the scaffold group.ConclusionsActivity level and MRI appearance following treatment of cartilage lesions with the biphasic synthetic scaffold were superior to microfracture over time in this nonrandomized, retrospective comparison.

BackgroundCell-based cartilage restoration with autologous chondrocyte implantation (ACI) is a safe and effective treatment for symptomatic cartilage lesions. Many patients undergoing ACI have a history of prior surgery, including bone marrow stimulation (BMS). There is mounting evidence that a history of prior BMS may impede healing of the ACI graft.Purpose/hypothesisThe purpose of this study was to compare the failure rates of primary ACI with ACI after prior BMS. We hypothesized that ACI after BMS would have a significantly higher failure rate (defined as reoperation, conversion to arthroplasty, and/or imaging-based failure) compared with primary ACI.Study designSystematic review; Level of evidence, 4.MethodsA literature search was performed by use of PubMed and Embase databases for relevant articles published through October 2, 2020, to identify studies evaluating outcomes and failures rates of ACI after prior BMS in the knee.ResultsIncluded were 11 studies comprising 1479 ACI procedures. The mean age at surgery ranged from 18.3 to 39.1 years, and the mean follow-up ranged from 3 to 20.6 years. All studies reported failure rates. The overall failure rate was significantly higher in the patients who underwent ACI after BMS, at 26.4% compared with 14.8% in the ACI group (P

Cartilage has limited self-repair ability, leading to osteoarthritis postinjury and ultimately physical disability in people. In addition, cartilage injury is accompanied by loss of extracellular matrix (ECM) and infiltration of inflammation, which makes cartilage regeneration more difficult. In this study, a hybrid hydrogel of hydroxypropyl chitin and oxidized chondroitin sulfate (HPCH-OCS) with injectable and thermosensitive properties was prepared by a Schiff base reaction. In vitro, the HPCH-OCS hydrogel showed desirable biocompatibility and bioactivity by promoting chondrogenic differentiation of stem cells, maintaining the chondrocyte phenotype, and inhibiting proteins related to cartilage ECM catabolism under inflammatory conditions. In vivo, the HPCH-OCS hydrogel combined with microfracture could effectively repair cartilage defects and promote cartilage regeneration. In conclusion, the HPCH-OCS hydrogel has good biological and mechanical properties, and its combination with microfracture provides an effective strategy for clinical cartilage regeneration.

Knee injuries, particularly anterior cruciate ligament (ACL) damage and cartilage defects, are highly prevalent among athletes and affect their sports performance and long-term joint function. The purpose of this research was to evaluate the effectiveness of a comprehensive combination therapy approach for individuals with ACL and cartilage injuries. Twelve professional soccer players aged 18 to 30 years underwent bone–tendon–bone ACL reconstruction, microfracture cartilage repair surgery, and hyaluronic acid scaffold treatment. Early postoperative rehabilitation included immediate supervised physiotherapy and complete weight bearing. Follow-up assessments involved clinical evaluations, functional joint assessments, and magnetic resonance imaging (MRI) scans to measure cartilage defect repair and symptom alleviation. The results showed that patients resumed pain-free activities within 3–4 weeks and returned to their pre-injury level within 4.5 months. MRI demonstrated the absence of inflammatory reactions, repair of marrow edema, and the emergence of new cartilage. Six months and one year after surgery, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Short Form (36) Health Survey (SF-36) questionnaire results demonstrated considerable improvement in patients' health condition and quality of life. Overall, the study suggests that the combination of Hyalofast membranes, microfracture surgery, tissue adhesive, and intensive postoperative physical therapy may be a potential alternative to commonly used treatments for patients with ACL rupture, allowing them to recover efficiently and return to sports activities. [ABSTRACT FROM AUTHOR]

Many patients, particularly those aged above 40, experience knee joint pain, which hampers both sports activities and daily living. Treating isolated chondral and osteochondral defects in the knee poses a significant clinical challenge, particularly in younger patients who are not typically recommended partial or total knee arthroplasty as alternatives. Several surgical approaches have been developed to address focal cartilage defects. The treatment strategies are characterized as palliation (e.g., chondroplasty and debridement), repair (e.g., drilling and microfracture), or restoration (e.g., autologous chondrocyte implantation, osteochondral autograft, and osteochondral allograft). This review offers an overview of the commonly employed clinical methods for treating articular cartilage defects, with a specific focus on the clinical trials conducted in the last decade. Our study reveals that, currently, no single technology fully meets the essential requirements for effective cartilage healing while remaining easily applicable during surgical procedures. Nevertheless, numerous methods are available, and the choice of treatment should consider factors such as the location and size of the cartilage lesion, patient preferences, and whether it is chondral or osteochondral in nature. Promising directions for the future include tissue engineering, stem cell therapies, and the development of pre-formed scaffolds from hyaline cartilage, offering hope for improved outcomes. [ABSTRACT FROM AUTHOR]

Background: While concomitant full-thickness rotator cuff tears and glenoid osteochondral defects are relatively uncommon in younger patients, military patients represent a unique opportunity to study this challenging injury pattern. Purpose/Hypothesis: To compare the outcomes of young, active-duty military patients who underwent isolated arthroscopic rotator cuff repair (ARCR) with those who underwent ARCR plus concurrent glenoid microfracture (ARCR+Mfx). It was hypothesized that ARCR+Mfx would produce significant improvements in patient-reported outcome measures. Study Design: Cohort study; Level of evidence, 3. Methods: This was a retrospective analysis of consecutive active-duty military patients from a single base who underwent ARCR for full-thickness rotator cuff tears between January 2012 and December 2020. All patients were <50 years and had minimum 2-year follow-up data. Patients who underwent ARCR+Mfx were compared with those who underwent isolated ARCR based on the visual analog scale (VAS) for pain, Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons (ASES) shoulder score, and range of motion. Results: A total of 88 patients met the inclusion criteria for this study: 28 underwent ARCR+Mfx and 60 underwent isolated ARCR. The mean final follow-up was 74.11 ± 33.57 months for the ARCR+Mfx group and 72.87 ± 11.46 months for the ARCR group (P =.80). There were no differences in baseline patient characteristics or preoperative outcome scores between groups. Postoperatively, both groups experienced statistically significant improvements in all outcome scores (P <.0001 for all). However, the ARCR+Mfx group had significantly worse VAS pain (1.89 ± 2.22 vs 1.03 ± 1.70; P =.05), SANE (85.46 ± 12.99 vs 91.93 ± 12.26; P =.03), and ASES (86.25 ± 14.14 vs 92.85 ± 12.57; P =.03) scores. At the final follow-up, 20 (71.43%) patients in the ARCR+Mfx group and 53 (88.33%) patients in the ARCR group were able to remain on unrestricted active-duty military service (P =.05). Conclusion: Concomitant ARCR+Mfx led to statistically and clinically significant improvements in patient-reported outcome measures at the midterm follow-up. However, patients who underwent ARCR+Mfx had significantly worse outcomes and were less likely to return to active-duty military service than those who underwent isolated ARCR. The study findings suggest that ARCR+Mfx may be a reasonable option for young, active patients who are not candidates for arthroplasty. [ABSTRACT FROM AUTHOR]

In order to quantitatively characterize shale pores and microfractures, twelve marine shale samples from the Longmaxi Formation in the southeastern Sichuan Basin were selected and their NMR T2 spectra were analyzed under the conditions of full brine saturation, cyclic centrifugal treatment and cyclic heat treatment. Then, movable, capillary bound and unrecoverable fluid of shale samples were distinguished and the NMR porosity and full-scale PSD were calculated. Based on NMR spectral peak identification, the relative content of pores and microfractures was determined and their influence factors were analyzed. The results show that the PSD of shale samples is bimodal, with pores distributed in the range of 1 nm to 200 nm and microfractures distributed in the range of 200 nm to 5000 nm, with relative contents in the ranges of 3.44–6.79% and 0.22–1.43%, respectively. Nanoscale organic pores are the dominant type of pores, while inorganic pores and microfractures contribute much less to the shale reservoir space than organic pores. The T2 cutoff values range from 0.55 ms to 6.73 ms, and the surface relaxivities range from 0.0032 µm/ms to 0.0391 µm/ms. Their strong correlation with TOC suggests that organic matter is the main factor controlling the pore type and structure. In addition, the main difference between NMR porosity and He porosity is that gas logging porosity is used to detect connected pores, while NMR porosity also includes closed pores and microfractures. Combined with NMR and high-temperature pressure displacement experimental facilities, this will be a further step towards studying the pore structure of shale under simulated formation conditions. [ABSTRACT FROM AUTHOR]

Constrained by the geological burial history of Cretaceous Qingshuihe Formation in the southern margin of Junggar Basin, the diagenetic physical simulation experiment was carried out with the low-mature sandstone samples taken from the outcrop area. Then, coupling with the regional geological data, the reformation of reservoirs with different diagenetic intensities by microfractures and the significance of microfractures for development of high-quality reservoirs were discussed. The results show that the large-scale microfractures were formed in the stage of late rapid deep burial, roughly equivalent to the period when organic acids were filled. The microfractures created good conditions for migration of oil and gas in deep and ultra-deep clastic rocks, and also enabled the transport of organic acids to the reservoirs for ensuing the late continuous dissolution of cements and particles. The existence of matrix pores and microfractures in the reservoirs before the rapid deep burial determined how the microfractures formed during rapid deep burial improved the reservoir quality. If matrix pores and microfractures were more developed and the cementation degree was lower before the rapid deep burial, the microfractures would be more developed and the dissolution degree would be higher during the late rapid deep burial, and so the reservoir quality would be improved more greatly, which can increase the reservoir permeability by up to 55%. If cementation was very strong, but matrix pores were not developed and microfractures existed locally before the rapid deep burial, the microfractures would also be more developed during the late rapid deep burial, which can increase the reservoir permeability by 43%. If cementation was strong, matrix pores were absent, and microfractures were not developed, limited microfractures would be formed during the late rapid deep burial, which can increase the reservoir permeability by only 16%. Formation of large-scale microfractures during late rapid deep burial and promotion of such microfractures to the dissolution of organic acids are considered as key diagenetic factors for the development of deep and ultra-deep high-quality reservoirs.

Using an industrial CT scanning system, we observed the characteristics of micro-fracture Generation and expansion in coal under different gas pressure conditions, providing a new basis for revealing the factors controlling the gas flow output of coal seams. The results of the test analysis showed that: under the action of non-adsorbed gas, the growth rate of fracture volume and fracture area percentage decreases gradually as the pore pressure increases and the sprouting and expansion of microfractures inside coal becomes more obvious. Fracture expansion equation under the influence of pore pressure is satisfied; microfracture extension is mainly controlled by stress concentration effect and coal matrix shrinkage effect. Under the action of adsorptive gas, with the extension of adsorption time, generation and expansion in coal of micro fissures become more and more significant until the expansion equilibrium; the growth rate of fissure volume and fissure area percentage then gradually becomes smaller, in line with the fissure expansion equation under the influence of adsorption time; the fracture extension is mainly affected by stress concentration effect, coal matrix shrinkage effect, erosion effect and deterioration mechanism. The larger the adsorption pressure the longer the adsorption equilibrium time required for the coal; the micro fissure expansion equilibrium time is longer than the gas adsorption equilibrium time, and the fissure expansion has obvious hysteresis.

Objective: This study aimed to investigate the clinical outcomes of medial opening high tibial osteotomy (MOWHTO) combined with arthroscopic microfracture in the treatment of varus medial compartmental knee osteoarthritis and to assess cartilage regeneration using second-look arthroscopy.Methods: This study involved 86 patients (86 knees) who underwent MOWHTO and microfracture from August 2016 to August 2020, including 15 men and 71 women with an average age of 55.3 ± 7.6 years (range, 42–71 years). The patients underwent a second-look arthroscopy to evaluate the status of cartilage regeneration at the time of plate removal, an average of 2 years after the initial osteotomy. Clinical and radiological examinations were performed preoperatively and at the final follow-up visit. The radiologic evaluation included the weight-bearing line ratio (WBL ratio), mechanical femorotibial angle (FTA), medial proximal tibial angle (MPTA), posterior tibial slope angle (PTS) and Kellgren-Lawrence (KL) grade. Clinical outcomes were assessed using the Knee Society score (KSS) and International Knee Documentation Committee (IKDC) scores. Arthroscopic findings were assessed by macroscopic evaluation of cartilage repair according to the International Cartilage Repair Society (ICRS) grading system.Results: The mean KSS and IKDC scores significantly improved at the final follow-up compared to the scores obtained preoperatively (p < 0.05). At the time of plate removal, a second-look arthroscopic examination showed that the ICRS grade of the medial femoral condyle was as follows: grade I −11 cases, grade II -56, grade III-12, and grade IV-7, and cartilage regeneration was seen in 85% of knees (73/86). The ICRS grade of medial tibial plateau was grade I-12 cases, grade II-44, grade III-22, and grade IV-8, and cartilage regeneration was seen in 63% of knees (54/86). Significant differences were observed between cartilage regeneration and clinical outcomes (p < 0.05). Clinical results were better in the good cartilage regeneration group (grades I and II) than were in the poor cartilage regeneration group (grades III and IV).Conclusion: MOWHTO combined with arthroscopic microfracture can effectively improve clinical outcomes in the treatment of varus medial compartmental knee osteoarthritis. Cartilage regeneration can be promoted by correcting varus deformities, which affect clinical outcomes.

Due to its avascular organization and low mitotic ability, articular cartilage possesses limited intrinsic regenerative capabilities. The aim of this study is to achieve one-step cartilage repair in situ via combining bone marrow stem cells (BMSCs) with a xenogeneic Acellular dermal matrix (ADM) membrane. The ADM membranes were harvested from Sprague-Dawley (SD) rats through standard decellularization procedures. The characterization of the scaffolds was measured, including the morphology and physical properties of the ADM membrane. The in vitro experiments included the cell distribution, chondrogenic matrix quantification, and viability evaluation of the scaffolds. Adult male New Zealand white rabbits were used for the in vivo evaluation. Isolated microfracture was performed in the control (MF group) in the left knee and the tested ADM group was included as an experimental group when an ADM scaffold was implanted through matching with the defect after microfracture in the right knee. At 6, 12, and 24 weeks post-surgery, the rabbits were sacrificed for further research. The ADM could adsorb water and had excellent porosity. The bone marrow stem cells (BMSCs) grew well when seeded on the ADM scaffold, demonstrating a characteristic spindle-shaped morphology. The ADM group exhibited an excellent proliferative capacity as well as the cartilaginous matrix and collagen production of the BMSCs. In the rabbit model, the ADM group showed earlier filling, more hyaline-like neo-tissue formation, and better interfacial integration between the defects and normal cartilage compared with the microfracture (MF) group at 6, 12, and 24 weeks post-surgery. In addition, neither intra-articular inflammation nor a rejection reaction was observed after the implantation of the ADM scaffold. This study provides a promising biomaterial-based strategy for cartilage repair and is worth further investigation in large animal models. [ABSTRACT FROM AUTHOR]

The appropriate surgical management of osteochondral lesions of the talus (OLT) remains a challenge for foot and ankle surgeons. Currently, microfracture (MF) is the first-line operative treatment for small osteochondral lesions. However, the fibrous cartilage regenerated after MF is mechanically inferior to hyaline cartilage regeneration and is susceptible to deterioration over time. Thus, this meta-analysis aimed to elucidate the efficacy of platelet-rich plasma (PRP) augmentation compared with MF only or other adjuvant supplementations combined with the PRP + MF group (others) for the management of OLT. We searched the PubMed, Embase, Web of Science, and Cochrane Library databases for studies that compared the clinical outcomes of patients who underwent MF only and those who underwent PRP or other adjuvant materials such as hyaluronic acid or BST-CarGel. After the screening, four randomized controlled trials and one quasi-randomized controlled trial were included in this review. We used the following tools for clinical evaluation: the American Orthopedic Foot and Ankle Society (AOFAS) score, Ankle–Hindfoot Scale score, Visual Analog Scale (VAS) score for pain, and the Foot and Ankle Ability Measure (FAAM) score. The standardized mean difference (SMD) was used to analyze the differences in outcomes between groups. Patients in the PRP + MF group had superior final VAS and AOFAS scores to the MF only group. (both p < 0.01) However, no significant improvements between baseline and final follow-up were noted in either score. In addition, there was no remarkable difference in the overall FAAM pain measures between the two groups. The PRP + MF and others groups revealed no significant effect differences in the clinical scores. The results of this analysis suggest that PRP + MF would be more favorable and effective than MF only or additional adjuvant supplementation. [ABSTRACT FROM AUTHOR]

Osteochondral lesions of the talus (OLTs) are a difficult pathologic entity to treat. They require a strong plan. Lesion size, location, chronicity, and characteristics such as displacement and the presence of subchondral cysts help dictate the appropriate treatment required to achieve a satisfactory result. In general, operative treatment is reserved for patients with displaced OLTs or for patients who have failed nonoperative treatment for 3 to 6 months. Operative treatments can be broken down into cartilage repair, replacement, and regenerative strategies. There are many promising treatment options, and research is needed to elucidate which are superior to minimize the morbidity from OLTs. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to compare the microfracture (MF) technique with the bioscaffold solution application (BST-CarGel) in treating femoral chondral lesions. Methods: Thirty-eight patients ages 18–45 with isolated single femoral condyle full-thickness (ICRS grade 3–4) chondral lesions were included in the study. Patients were divided into two groups as MF applied (Group I = 21) and bioscaffold combined with MF (Group II = 17). The visual analog scale (VAS), Western-Ontario, and McMaster Osteoarthritis Index (WOMAC) were used in clinical evaluation. The location, size, and depth of lesions were evaluated with preoperative magnetic resonance imaging (MRI). Magnetic resonance observation of cartilage repair tissue (MOCART) score was used for postoperative evaluation. Results: The mean age was 32.5 (range 19–44) years. Mean follow-up was 14.9 months (range 12–24). Lesion size was 3 cm2 in group I and 2.9 cm2 in group II. There were no differences between groups regarding demographic characteristics but BMI (Body Mass Index) was lower in group II which was significant. The duration of surgery was longer in group II (p < 0.001). Postoperative statistical significant improvements were found in WOMAC and VAS scores in groups, but there was no statistical difference. Although there was no significant radiological difference in the group II according to the MOCART score, higher scores were obtained compared to group I. Conclusion: No difference was found, clinical and radiological, in terms of short-term outcomes. MF is a method to be applied as a primary treatment with its cost-effective, simple and short surgery technique, and effective clinical results up to 4 cm2. Level of Evidence: Level III: retrospective comparative study. [ABSTRACT FROM AUTHOR]