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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.

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.

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.

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

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.

Background: To present midterm patient-reported outcomes and survivorship data of active-duty military patients undergoing microfracture for full-thickness cartilage defects of the glenoid. Methods: All consecutive patients from January 2013 through December 2016 who underwent glenoid microfracture for full-thickness cartilage injuries with complete outcome scores were identified. Twenty patients met the final inclusion criteria for the study, and all were active-duty military at the time of surgery. A separate subgroup analysis was performed to determine if dominant-shoulder involvement portends worse outcomes. Results: The mean follow-up was 81.45 ± 19.43 months (range, 60-108). Of the 20 patients, 5 required a secondary surgical procedure within 5 years of their index procedure, with an average time to failure of 45.6 ± 13.15 months. For the 15 patients who did not fail, there was a statistically significant increase in the mean American Shoulder and Elbow Surgeons score (57.20 vs. 88.27, P

The pore structure controls the storage and migration of geofluids within shale and ultimately determines its reservoir quality. Therefore, the characterization of shale pore structure has become more and more meaningful in geological engineering research. Due to the complicate sampling procedure and relatively high cost, the shale core samples are usually less in quantity and quite precious. Consequently, the shale outcrop samples, which were deposited in the similar sedimentary environment with shale core samples in the same layer, are always used to indicate reservoir characteristics. However, the pore structure similarities and differences between shale outcrop and core samples in the same layer is still unknown, which restricts the effective use of outcrop samples in shale pore structure characterization and requires detailed investigation. In this study, the pore structure of the outcrop and core samples of Jurassic Ziliujing Formation shale with high clay content from the Northeastern Sichuan Basin in China is quantitatively characterized by N2adsorption and high-pressure mercury intrusion porosimetry (HPMIP) experiment and is semi-quantitatively revealed by field emission scanning electron microscope (FE-SEM) experiment. The results show that there is an obvious pore structure parameter difference between outcrop and core samples: the average specific surface area of outcrop samples is 8.47 times that of core samples, the average pore volume of outcrop samples is 1.83 times that of core samples; the average microfracture development level of outcrop samples is 1.43 times that of core samples, which is mainly caused by the higher microfracture development level of clay minerals in outcrop samples; the microfracture development direction is chaos in outcrop samples but relatively in order in core samples. However, there are still some pore structure similarities between outcrop and core samples: the whole-aperture pore structure distribution of outcrop and core samples has two similar distribution peaks at 15 ∼22 nm and 25 ∼42 nm; outcrop samples and core samples have similar pore space contributors: clay minerals (CM) pores > organic matter (OM) pores + quartz and feldspar (QF) pores while microfractures are mainly provided by clay minerals; the pore size distribution of OM and QF pores in outcrop samples were also similar to core samples. Overall, the pore structure of outcrop samples has certain indicative significance in terms of main pore size distribution interval, the relative contribution of different types of pores and the pore characteristics of OM, which shows the limited applicability of outcrop samples in shale pore structure characterization.

Background: This study aims to prove the healing results (regeneration) in cartilage defects using a combination treatment of microfractures and transplantation synovium-platelet rich fibrin (S-PRF). Methods: A cartilage defect was made in the trochlear groove of the knee of adult New Zealand white rabbits, and was classified into three treatment groups. The group 1 was cartilage defect without treatment, 2 with microfracture treatment, and 3 with microfracture covered with a synovium-platelet rich fibrin (S-PRF) membrane. Twelve weeks after the intervention, the animals were macroscopically and histologically examined, and evaluated by the International Cartilage Repair Society (ICRS). Additionally, the expression of aggrecan and type 2 collagen was examined by real-time-PCR. Results: The ICSR scores for macroscopic were significantly higher in the microfracture and S-PRF transplant group than in the other groups. Also, the ICSR scores for histology were significantly higher in this group. The expression of aggrecan and type 2 collagen was higher in the group that received complete treatment. Conclusions: Microfractures and transplantation of synovium-platelet rich fibrin (S-PRF) can regenerate knee cartilage defects which have been shown to increase the expression of mRNA aggrecan and mRNA type 2 collagen resulting in excellent repair.

Insufficiency fractures of the body of the calcaneus are a rare pathology, typically seen in women with osteoporosis. Our patient was seen by multiple physicians over the course of the year with no symptomatic relief. Her previous treatments included serial heel injections, physical therapy and non-weight bearing in a short leg synthetic cast. Initial radiographs revealed no osseous pathology that correlated with the area of pain and swelling. Magnetic resonance imaging (MRI) was obtained which suggested findings for an insufficiency fracture with increased signal intensity on T2 and decreased signal intensity on T1 in the calcaneus. The patient opted for surgical management and underwent subchondroplasty and repair with microfracture of the left calcaneus. At the first post-operative appointment she had significant pain relief, and she was later able to resume her previous activities pain free. This case demonstrates the importance of maintaining insufficiency fractures as a differential diagnosis and the success of using microfracture and subchondroplasty when non-surgical measures have failed.

Articular cartilage defects fail to heal spontaneously, typically progressing to osteoarthritis. Bone marrow stimulation techniques such as microfracture (MFX) are the current surgical standard of care; however MFX typically produces an inferior fibro-cartilaginous tissue which provides only temporary symptomatic relief. Here we implanted solubilised articular cartilage extracellular matrix (ECM) derived scaffolds into critically sized chondral defects in goats, securely anchoring these implants to the joint surface using a 3D-printed fixation device that overcame the need for sutures or glues. In vitro these ECM scaffolds were found to be inherently chondro-inductive, while in vivo they promoted superior articular cartilage regeneration compared to microfracture. In an attempt to further improve the quality of repair, we loaded these scaffolds with a known chemotactic factor, transforming growth factor (TGF)-β3. In vivo such TGF-β3 loaded scaffolds promoted superior articular cartilage regeneration. This study demonstrates that ECM derived biomaterials, either alone and particularly when combined with exogenous growth factors, can successfully treat articular cartilage defects in a clinically relevant large animal model.

Microfractures can obviously improve physical properties and connectivity of tight reservoir, which is an important factor to control the exploration and development of tight oil and gas. However, there is little quantitative research on microfracture, thus, its reservoir mechanism is not clear. Taking the Cretaceous tight reservoir in the Liuhe Basin as an example, the microstructure characteristics of fractures were discussed on micron and nanometer scale respectively, and their contribution to physical properties was revealed in this paper. The results show that a small number of intercrystalline pores, intergranular pores and dissolution pores are developed in the Cretaceous tight reservoirs, and microfractures are the main reservoir space. The width of nano-sized fracture is mainly in the range from 2 nm to 300 nm, in which the proportion of fractures with larger width increases obviously with the increase of buried depth, and its contribution to pore volume is also greater. The width of micron-sized fracture is mainly in the range from 2.95 μm to 114 μm, and micron-sized fracture is much more developed with the increase of burial depth. Although the distribution frequency of micron-sized fracture is much smaller than that of nano-sized microfracture, it makes a greater contribution to permeability.

Background: Cartilage defects are treated with a wide array of non-operative and surgical procedures. Optimal choice of treatment depends on lesion depth and size. Objectives: To review and summarize current data on the management of cartilage injuries in joints as it relates to defect size. Data sources: MEDLINE, Cochrane Central Register of Controlled Trials & Cochrane Library, CINHAL. Study eligibility criteria, participants, and interventions: Inclusion: (1) Studies investigating patients who underwent cartilage repair of the shoulder, elbow, hip, knee, and ankle. (2) Studies reporting outcome measures and treated lesion size. Exclusion: (1) No mention of defect size. (2) Joints not mentioned above. (3) 1.5 cm2 mostly addressed with cell-based therapies such as autologous cartilage implantation (ACI), or matrix associated cartilage implantation (MACI). Large lesions often are the domain of osteochondral autograft transfer system (OATS). Limitations: Prospective randomized controlled studies are not available for every joint and many studies represent case studies with limited implications for treatment decisions. Conclusions and implications of key findings: Evidence-based treatment selection based on cartilage defect size can be beneficial. Systematic review registration number: 276559.

Introduction: The prevalence of focal cartilage defects in elite athletes is estimated to be as high as 36%, and treatment in professional football players poses a complex clinical challenge. Marrow stimulation is a common treatment option for athletes with symptomatic, contained, full-thickness chondral injuries. Objectives: To report the current indications for and efficacy of marrow stimulation in football players. Methods: PubMed, Scopus, and Embase were searched. All levels of evidence (I-IV) pertaining to marrow stimulation in football players were analyzed and presented in a narrative review. Results: Reported return to sport rates following microfracture range from 52% to 95%, with up to 67% of athletes returning to preinjury level of performance. Clinical outcomes improve shortly after microfracture but may decline by 2 years postoperatively. Augmented marrow stimulation techniques have since been developed in an effort to improve repair quality and clinical outcomes, though supporting data is limited. Conclusion: In professional football players, marrow stimulation is a viable treatment for the repair of small (

Background and aims: Previous work has shown that oral losartan can enhance microfracture-mediated cartilage repair in a rabbit osteochondral defect injury model. In this study, we aimed to determine whether oral losartan would have a detrimental effect on articular cartilage and bone homeostasis in the uninjured sides. Methods: New Zealand rabbits were divided into 4 groups including normal uninjured (Normal), contralateral uninjured side of osteochondral defect (Defect), osteochondral defect plus microfracture (Microfracture) and osteochondral defect plus microfracture and losartan oral administration (10 mg/kg/day) (Losartan). Rabbits underwent different surgeries and treatment and were sacrificed at 12 weeks. Both side of the normal group and uninjured side of treatment groups tibias were harvested for Micro-CT and histological analysis for cartilage and bone including H&E staining, Herovici's staining (bone and cartilage) Alcian blue and Safranin O staining (cartilage) as well as immunohistochemistry of losartan related signaling pathways molecules for both cartilage and bone. Results: Our results showed losartan oral treatment at 10 mg/kg/day slightly increase Alcian blue positive matrix as well as decrease collagen type 3 in articular cartilage while having no significant effect on articular cartilage structure, cellularity, and other matrix. Losartan treatment also did not affect angiotensin receptor type 1 (AGTR1), angiotensin receptor type 2 (AGTR2) and phosphorylated transforming factor β1 activated kinase 1 (pTAK1) expression level and pattern in the articular cartilage. Furthermore, losartan treatment did not affect microarchitecture of normal cancellous bone and cortical bone of tibias compared to normal and other groups. Losartan treatment slightly increased osteocalcin positive osteoblasts on the surface of cancellous bone and did not affect bone matrix collagen type 1 content and did not change AGTR1, AGTR2 and pTAK1 signal molecule expression. Conclusion: Oral losartan used as a microfracture augmentation therapeutic does not have significant effect on uninjured articular cartilage and bone based on our preclinical rabbit model. These results provided further evidence that the current regimen of using losartan as a microfracture augmentation therapeutic is safe with respect to bone and cartilage homeostasis and support clinical trials for its application in human cartilage repair.

This study aimed to investigate the crucial geometric distinctions of microfractures as the indispensable transportation channels in hydrocarbon-rich shale so as to find the new evidence for hydrocarbon exploration and exploitation.This study mainly shows that (1) microfracture length and width would show a good positive linear correlation, but when the length of microfracture reaches a key point, the width of microfracture would gradually deviate from the linear relationship and gradually diverges. (2) compaction or other tectonic stress can promote the formation of shale microfractures and promote the occurrence of pressure solution. (3) Similarly, before a certain key point, the poor orientation degree of microfractures often coexists with the higher convexity of microfractures, which is positively correlated. When this key point is crossed, the two begin to show a negative correlation. This may be due to the fact that the microfractures will open, close, extend or even interlace more frequently when the rock is under complex stress conditions.It proved that when describing the heterogeneity characteristics of microfractures, we should clearly describe them from two aspects of size and geometry so as to ensure the integrity of the conclusion.

Introduction: Microfracture has been widely published as a treatment for osteochondral lesions of the talus (OLT). Little is known about the outcome predictors following microfracture for smaller sized OLT. Objectives: This study sought to define the outcome predictors for small OLT treated with microfracture and concentrated bone marrow aspirate (CBMA). Our hypothesis was that lesion uncontainment and the presence of cysts were predictors of poor outcomes following microfracture with CBMA for OLT. Methods: A retrospective cohort study investigating patients who received microfracture for OLT (

The analysis of the distribution of microfractures and micropores is important to accurately characterise mass transfer within a rock body. In this paper, a new ‘simultaneous polarization–fluorescence microscopy’ method is presented, which can be used to analyse the distribution of microscopic voids, including microfractures and micropores, in granitic rock. In this method, thin sections prepared with fluorescent dye are analysed under a polarizing microscope equipped with a fluorescent reflected light source. Using both the transmitted and the fluorescent light sources, both the distribution of microfractures and micropores, and petrographic characteristics (mineral occurrences) can be determined efficiently and simultaneously. The distribution of microfractures and micropores observed in images of granites obtained using simultaneous polarization–fluorescence microscopy is consistent with the distribution observed in backscattered electron images. The low magnification characterisation of the distribution of microscopic voids also provides targeting for subsequent studies including scanning electron microscopy under high magnification, chemical analysis, and image processing.

Articular cartilage is found at the distal end of long bones and is responsible for assisting in joint articulation. While articular cartilage has remarkable resistance to failure, once initially damaged, degeneration is nearly irreversible. Thus, understanding damage initiation is important. There are a few proposed mechanisms for articular cartilage failure initiation: (A) a single collagen fibril stress-based regime; (B) a rate-dependent regime captured by brittle failure at slow displacement rates (SDR) and ductile failure at fast displacement rates (FDR); and (C) a rate-dependent regime where failure is governed by pressurization fragmentation at SDR and governed by strain at FDR. The objective of this study was to use finite element (FE) models to provide evidence to support or refute these proposed failure mechanisms. Models were developed of microfracture experiments that investigated osmolarity (hypo-osmolar, normal osmolarity, and hyper-osmolar) and displacement rate (FDR and SDR) effects. Cartilage was modeled with a neo-Hookean ground matrix, strain-dependent permeability, nonlinear fibril reinforcement with viscoelastic fibril terms, and Donnan equilibrium swelling. Total stress, solid matrix stress, Lagrange strain, and fluid pressure were determined under the indenter tip at the moment of microfracture. Results indicated significant rate dependence across multiple outputs, which does not support (A) a single failure regime. Larger solid and fluid pressures at FDR than SDR did not support (C) a rate-dependent regime split by pressurization at SDR and strain at FDR. Consistent solid shear stresses at SDR and consistent third principal solid stresses at FDR support (B) the ductile-brittle failure regime. These findings help to shed light on the underlying mechanisms of articular cartilage failure, which have implications for the development of osteoarthritis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

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., Competing Interests: All authors involved in this article declare that there are no conflicts of interest regarding the publication of this paper., (© 2023 The Authors.)

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. STATEMENT OF SIGNIFICANCE: 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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Objectives: In the aging population, the knee is the joint most commonly causing impaired function and incapacity. While definite treatment by prosthetic replacement is often performed late, symptomatic knee cartilage lesions cause much suffering also in younger ages. Early intervention could, therefore, be instituted at an early stage to the benefit of both patients and society. Small, metal surface, resurfacing implants have been tested with promising results. A system that features patient-specific implants and surgical instruments shows good clinical results and favorable survival rates. This study aims to assess the cost utility of this metal device compared with microfracture (MFX), being the standard procedure in Sweden., Methods: We constructed a simulation model in Excel. In the model, a cohort of 47-year-old patients (which is the mean age of patients treated with the metal implant) with symptomatic knee cartilage lesions received either MFX or metal implantation. Outcomes for the cohort were simulated over 40 years, such as in a previously published model based on MFX, and sensitivity analyses (deterministic and probabilistic) of the results were undertaken. Data on transition probabilities, costs, and quality of life were taken from clinical data, published literature, and official price lists. Only direct medical costs were included., Results: Results from the analysis showed that the metal device is a cost-effective treatment strategy compared with MFX. The incremental cost-effectiveness ratio (ICER) reached acceptable levels at ∼5 years postoperatively. Over the full-time horizon of 40 years, the metal device was cost saving with concomitant gains in quality-adjusted life years (QALYs), translating to a dominant treatment strategy. Results were robust according to sensitivity analysis with the initial success rate of up to three years for both metal and MFX having the largest impact., Conclusions: A metal implant may be a cost-effective treatment alternative for patients in their 40's when compared to MFX in a Swedish setting., Level of Evidence: 5 [1]., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Debate continues as to whether surgical treatment with chondral-regeneration devices is superior to microfracture for focal articular cartilage defects in the knee., Purpose: To evaluate the superiority of scaffold-associated chondral-regeneration procedures over microfracture by assessing: (1) Patient-reported outcomes; (2) Intervention failure; (3) Histological quality of cartilage repair., Study Design: A three-concept keyword search strategy was designed, in accordance with PRISMA guidelines: (i) knee (ii) microfracture (iii) scaffold. Four databases (Ovid Medline, Embase, CINAHL and Scopus) were searched for comparative clinical trials (Level I-III evidence). Critical appraisal used two Cochrane tools: the Risk of Bias tool (RoB2) for randomized control trials and the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I). Study heterogeneity permitted qualitative analysis with the exception of three patient-reported scores, for which a meta-analysis was performed., Results: Twenty-one studies were identified (1699 patients, age range 18-66 years): ten randomized control trials and eleven non-randomized study interventions. Meta-analyses of the International Knee Documentation Committee (IKDC), Knee Injury And Osteoarthritis Outcome Score (KOOS) for pain and activities of daily living, and Lysholm score demonstrated statistically significant improvement in outcomes for scaffold procedures compared to microfracture at two years. No statistical difference was seen at five years., Conclusion: Despite the limitations of study heterogeneity, scaffold-associated procedures appear to be superior to MF in terms of patient-reported outcomes at two years though similar at five years. Future evaluation would benefit from studies using validated clinical scoring systems, reporting failure, adverse events and long-term clinical follow up to determine technique safety and superiority., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023. Published by Elsevier B.V. All rights reserved.)

Purpose: Osteochondritis dissecans (OCD) of the capitellum is often treated by marrow stimulation techniques with good long-term outcomes. Magnetic resonance imaging (MRI) can be used to characterize the healing of cartilage repair tissue. However, no formal system exists for assessment of cartilage healing after marrow stimulation in capitellar OCD. The aims of this study were to describe the postoperative MRI appearance of capitellar repair cartilage after debridement and marrow stimulation for capitellar OCD and assess differences between symptomatic and asymptomatic patients., Methods: This was a retrospective study of patients with capitellar OCD who underwent arthroscopic debridement and marrow stimulation and had a postoperative MRI to assess healing. The classification system developed by Marlovits and colleagues (Magnetic Resonance Observation of Cartilage Repair Tissue) was used to quantitatively profile the cartilage repair tissue in comparison to adjacent "normal" cartilage. Study participants completed an online survey to correlate outcomes with cartilage appearance., Results: Eleven patients who underwent MRI for routine evaluation (asymptomatic), and 18 who underwent MRI for symptoms were identified. Overall, 59% of defects were completely filled, and in 83%, the cartilage surface had ulcerations or fibrillations. The cartilage variables were similar between symptomatic and asymptomatic patients. Capitellar subchondral bone edema was observed on the MRI of every patient who underwent a reoperation and was present in only 62% of those who did not. Clinical scores did not correlate with MRI cartilage findings, but the small sample size limited conclusions regarding clinical outcomes related to postoperative cartilage features seen on MRI., Conclusions: This detailed assessment of cartilage appearance by MRI after marrow stimulation for capitellar OCD demonstrated that incomplete cartilage fill was common in both symptomatic and asymptomatic patients. Those requiring a second surgery were more likely to demonstrate subchondral bone edema., Type of Study/level of Evidence: Diagnostic IV., (Copyright © 2023 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Clinically, microfracture is the most commonly applied surgical technique for cartilage defects. However, an increasing number of studies have shown that the clinical improvement remains questionable, and the reason remains unclear. Notably, recent discoveries revealed that signals from regenerated niches play a critical role in determining mesenchymal stem cell fate specification and differentiation. We speculate that a microenvironmentally optimized scaffold that directs mesenchymal stem cell fate will be a good therapeutic strategy for cartilage repair. Therefore, we first explored the deficiency of microfractures in cartilage repair. The microfracture not only induced inflammatory cell aggregation in blood clots but also consisted of loose granulation tissue with increased levels of proteins related to fibrogenesis. We then fabricated a functional cartilage scaffold using two strong bioactive cues, transforming growth factor-β3 and decellularized cartilage extracellular matrix, to modulate the cell fate of mesenchymal stem cells. Additionally, poly(ε-caprolactone) was also coprinted with extracellular matrix-based bioinks to provide early mechanical support. The in vitro studies showed that microenvironmentally optimized scaffolds exert powerful effects on modulating the mesenchymal stem cell fate, such as promoting cell migration, proliferation and chondrogenesis. Importantly, this strategy achieved superior regeneration in sheep via scaffolds with biomechanics (restored well-organized collagen orientation) and antiapoptotic properties (cell death-related genes were also downregulated). In summary, this study provides evidence that microenvironmentally optimized scaffolds improve cartilage regeneration in situ by regulating the microenvironment and support further translation in human cartilage repair. STATEMENT OF SIGNIFICANCE: Although microfracture (MF)-based treatment for chondral defects has been commonly used, critical gaps exist in understanding the biochemistry of MF-induced repaired tissue. More importantly, the clinically unsatisfactory effects of MF treatment have prompted researchers to focus on tissue engineering scaffolds that may have sufficient therapeutic efficacy. In this manuscript, a 3D printing ink containing cartilage tissue-specific extracellular matrix (ECM), methacrylate gelatin (GelMA), and transforming growth factor-β3 (TGF-β3)-embedded polylactic-coglycolic acid (PLGA) microspheres was coprinted with poly(ε-caprolactone) (PCL) to fabricate tissue engineering scaffolds for chondral defect repair. The sustained release of TGF-β3 from scaffolds successfully directed endogenous stem/progenitor cell migration and differentiation. This microenvironmentally optimized scaffold produced improved tissue repair outcomes in the sheep animal model, explicitly guiding more organized neotissue formation and therefore recapitulating the anisotropic structure of native articular cartilage. We hypothesized that the cell-free scaffolds might improve the clinical applicability and become a new therapeutic option for chondral defect repair., Competing Interests: Declaration of Competing Interest All authors of this article have no conflicts of interest regarding the publication of this paper to declare., (Copyright © 2022. Published by Elsevier Ltd.)

This classic discusses the original publication "A method of resurfacing osteoarthritic knee joints" by Dr K.H. Pridie (1959), where this pioneer surgeon described a newly developed method for the treatment of osteoarthritic joint surfaces of the knee, which he named subchondral drilling. This short and concise 11-line publication appeared in the Proceedings of the Congress of the British Orthopaedic Association. It has generated 464 citations since 1959, becoming part of the hundred most-cited publications in knee research. Pridie introduced in clinical experimentation the entity of Marrow Stimulation Techniques to liberate mesenchymal stem cells from cancellous bone. He was aware that the results induced, in terms of quality of the regrown tissue, was limited and "only" fibrocartilage. His idea might have been raised from the work of numerous animal researchers who confirmed repeatedly since 1905 that cartilage needed an osseous perforation to heal. Although the past 60 years brought modifications from the technique described in the original article, the concept of marrow stimulation introduced by Pridie remains the most frequently used in cartilage repair surgery today., Competing Interests: Declaration of competing interest None declared., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The present study evaluated short-term outcomes of microfracture augmented with micronized allograft cartilage matrix (BioCartilage) and platelet-rich plasma (PRP) for symptomatic focal femoral condyle or trochlea cartilage defects., Methods: Patients who underwent microfracture augmented with BioCartilage and PRP for isolated contained chondral defects were evaluated. Magnetic resonance imaging (MRI) was performed at one year postoperatively. Two-year postoperative outcomes included patient-reported outcome measures (PROMs) and rates of return-to-work and return-to-sport., Results: Mean age of the 10 patients who completed the study was 39.7 years (range, 19-66 years), and five (50%) were female. Mean post-debridement defect size of the five femoral condyle and five trochlea defects was 2.4 cm 2 (range, 0.7-5.0 cm 2 ). One-year postoperative MRI analysis demonstrated that two chondral lesions were <50% filled, four sites were >50% filled, two sites were completely filled, and two sites had hypertrophied. Patients experienced improvements in three PROMs at six months, one year, and two years postoperatively (p < 0.01). Postoperative Marx Activity scores revealed no decrease in activity level compared to baseline preoperatively. Nine patients (90%) returned to their pre-injury level of work by one year postoperatively and remained at that level through two years postoperatively., Conclusions: Our findings suggest that small, contained focal chondral injuries in the femoral condyle and trochlea treated with a marrow stimulation procedure augmented with BioCartilage and PRP are associated with significant improvements in patient-reported outcomes at two years postoperatively. Further studies are needed to evaluate the long-term durability and imaging characteristics of this intervention. Level of evidence Therapeutic Level IV., Competing Interests: Declaration of competing interest The disclosures for the author group are as follows: C.M. Brusalis H.G. Greditzer P.D. Fabricant J.P. Stannard J.L. Cook, (Copyright © 2020 Elsevier B.V. All rights reserved.)

Surgical management of osteochondral lesions of the talus without an osteotomy depends on the size, location, and chronicity of the lesion. Bone marrow stimulation techniques, such as microfracture, can be performed arthroscopically and have consistently good outcomes in lesions less than 1 cm in diameter. For lesions not amenable to bone marrow stimulation, one-stage techniques, such as allograft cartilage extracellular matrix and allograft juvenile hyaline cartilage, may be used. Arthroscopy may be used in many cases to address these lesions; however, an arthrotomy may be required to use osteochondral autograft and allograft transplantation techniques., Competing Interests: Disclosure M. S. Conti: This author has nothing to disclose. J.K. Ellington: Amniox: paid consultant; Arthrex: IP royalties; Kinos: stock or stock options; Medline: IP royalties, paid consultant, paid presenter or speaker; Medshape: stock or stock options; Nuvasive: paid consultant; Synthes: IP royalties, paid consultant, paid presenter or speaker; Wright Medical Technology: paid consultant. S.B. Behrens: This author has nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: CARGEL (Smith & Nephew Inc.), a chitosan-based polymer scaffolding biomaterial, has been used since 2012 for treating articular cartilage lesions. Limited data are available on patient outcomes following CARGEL treatment. This study aimed to describe short-term clinical and radiographic outcomes in a cohort of patients treated with CARGEL and microfracture surgery for articular cartilage defects in the knee., Methods: A retrospective cohort study was conducted of consecutive patients with articular cartilage defects who had undergone microfracture surgery with CARGEL, or in patellar lesions microfracture and CARGEL plus Chondro-Gide (at SportsClinic Zurich). Study outcomes included reoperations, infections, allergic reactions, pain, swelling, range of motion, and tissue quality and quantity. Ethics approval was obtained from the local ethics committee on 05/09/2017 (Basec. Nr: 2017-01441)., Results: A total of 91 participants, with 93 treated lesions, consenting to chart review were included. No participants required reoperation due to complications on the index lesion. Fifteen participants had second-look surgery on the index knee for other reasons, allowing for visual confirmation of cartilage repair. No study participants experienced a post-surgical infection or suffered an allergic reaction. No significant changes in range of motion or T2 values were observed from pre-treatment to post-treatment follow-up. However, significant decreases were found in pain (P < 0.001) and swelling (P < 0.001), along with significant increases in MOCART II scores (P < 0.001). Similar results were found in a subgroup of patients with patellar lesions., Conclusions: Patients treated with CARGEL experienced few postoperative complications and reported promising reductions in pain and swelling after treatment., Level of Evidence: IV., (Copyright © 2018. Published by Elsevier B.V.)

Focal cartilage defects in the knee are commonly found on MRI and arthroscopically. When these lesions are symptomatic and fail nonoperative management several surgical strategies are available. Common surgical techniques include reparative (ie, microfracture) and restorative procedures (ie, autologous chondrocyte implantation, particulated juvenile allograft cartilage, osteochondral autograft transfer, and osteochondral allograft). Each of these surgical procedures have shared and novel complications associated with their use. This article provides a detailed, case-based discussion of common complications encountered in surgical procedures for focal cartilage defects of the knee, highlighting causes, clinical recognition, and how to address and avoid these complications., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate the outcome after cartilage repair surgery in focal defects of the knee by microfracture versus mosaicplasty., Methods: A cohort of 102 patients undergoing microfracture (n=52) or mosaicplasty (n=50) of a single articular cartilage defect in the medial femoral condyle of ≤50mm 2 was evaluated by Lysholm score before surgery, at six months, 12months, five years, 10years, and 15-18years after surgery., Results: Median age of patients at the time of surgery was 36years (range 16-58) and median follow-up time was 16years (range 14-18). Defects were treated with a median size of three square centimetres (range one to five). A significant increase was seen in the Lysholm score from mean 48 (SD 16) at baseline to 66 (SD 23; P<0.001) at the 15-18year follow-up. The Lysholm score was higher in the mosaicplasty group at six months, 12months, five years and 10years (P<0.05 for all comparisons). These differences were clinically significant at all points (>10 points). However, at the final follow-up, the difference (eight points) did not reach statistical significance., Conclusions: In the short-term, medium-term and long-term (10years), mosaicplasty in a single cartilage defect size one to five square centimetres of the femoral condyle resulted in clinically relevant better outcome than microfracture. However, at 15-18years after the surgery such a difference could not be found. In the six month to 10-15year (after surgery) perspective, the mosaicplasty procedure offered a better outcome in this type of lesion., Level of Evidence: Level III., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Although osteochondritis dissecans (OCD) has been a recognized condition for more than 100 years, our understanding of the etiology, natural history, and treatment remains poorly characterized. OCD most commonly affects the knee, followed by the elbow and ankle. Adolescents and young adults are most commonly affected. Patients present with vague, often intermittent symptoms and generally have no history of acute injury. Although diagnosis can be made with plain radiographs, treatment decisions are generally based on MRI. Skeletal maturity and stability of the OCD lesion determine treatment. Treatments range from immobilization and activity restriction to operative therapies. Clinical indications are discussed., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Articular cartilage damage remains a significant cause for early osteoarthritis in adolescents and young adults. After chondroplasty alone, the mainstay procedure for cartilage injuries is microfracture. Although in small lesions this may be successful long-term, positive results of treating larger lesions this way are less certain. This inconsistency in outcomes has led to augmentation of these defects with scaffolding for autograft regeneration or for allograft cartilage to fill the defect with a hyaline cartilage. This discussion includes current techniques for the addition of scaffolding to the microfracture defect for larger lesions, the rationale, and preliminary results., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: The aim of this systematic review was to identify high quality randomised controlled trials (RCTs) and to provide an update on the most appropriate surgical treatments for knee cartilage defects., Methods: Two reviewers independently searched three databases for RCTs comparing at least two different treatment techniques for knee cartilage defects. The search strategy used terms mapped to relevant subject headings of MeSH terms. Strict inclusion and exclusion criteria were used to identify studies with patients aged between 18 and 55 years with articular cartilage defects sized between one and 15cm 2 . Risk of bias was performed using a Coleman Methodology Score. Data extracted included patient demographics, defect characteristics, clinical outcomes, and failure rates., Results: Ten articles were included (861 patients). Eight studies compared microfracture to other treatment; four to autologous chondrocyte implantation (ACI) or matrix-induced ACI (MACI); three to osteochondral autologous transplantation (OAT); and one to BST-Cargel. Two studies reported better results with OAT than with microfracture and one reported similar results. Two studies reported superior results with cartilage regenerative techniques than with microfracture, and two reported similar results. At 10years significantly more failures occurred with microfracture compared to OAT and with OAT compared to ACI. Larger lesions (>4.5cm 2 ) treated with cartilage regenerative techniques (ACI/MACI) had better outcomes than with microfracture., Conclusions: Based on the evidence from this systematic review no single treatment can be recommended for the treatment of knee cartilage defects. This highlights the need for further RCTs, preferably patient-blinded, using an appropriate reference treatment or a placebo procedure., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Compare histological outcomes after microfracture (MF), autologous chondrocyte implantation (ACI), and osteochondral autograft transfer (OATS)., Methods: Literature review using PubMed MEDLINE, SCOPUS, Cumulative Index for Nursing and Allied Health Literature (CINAHL), and Cochrane Collaboration Library. Inclusion criteria limited to English language studies International Cartilage Repair Society (ICRS) grading criteria for cartilage analysis after ACI (autologous chondrocyte implantation), MF (microfracture), or OATS (osteochondral autografting) repair techniques., Results: Thirty-three studies investigating 1511 patients were identified. Thirty evaluated ACI or one of its subtypes, six evaluated MF, and seven evaluated OATS. There was no evidence of publication bias (Begg's p=0.48). No statistically significant correlation was found between percent change in clinical outcome and percent biopsies showing ICRS Excellent scores (R(2)=0.05, p=0.38). Percent change in clinical outcome and percent of biopsies showing only hyaline cartilage were significantly associated (R(2)=0.24, p=0.024). Mean lesion size and histological outcome were not correlated based either on percent ICRS Excellent (R(2)=0.03, p=0.50) or percent hyaline cartilage only (R(2)=0.01, p=0.67). Most common lesion location and histological outcome were not correlated based either on percent ICRS Excellent (R(2)=0.03, p=0.50) or percent hyaline cartilage only (R(2)=0.01, p=0.67)., Conclusions: Microfracture has poorer histologic outcomes than other cartilage repair techniques. OATS repairs primarily are comprised of hyaline cartilage, followed closely by cell-based techniques, but no significant difference was found cartilage quality using ICRS grading criteria among OATS, ACI-C, MACI, and ACI-P., Level of Evidence: IV, meta-analysis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: We aimed to investigate the effect of adipose tissue-derived mesenchymal stem cells (ADSCs) on chondral healing using the microfracture (MF) technique., Methods: Thirty male rabbits were randomly divided into three groups. Standard cylindrical osteochondral defects (OCDs) were created in the weight-bearing areas of the medial condyles of all the right knees; the defects were four millimeters in diameter and two millimeters in depth. The control group (group A) was restricted to spontaneous healing. For group B, we performed MF with a 1.5-mm drill. For group C, we applied MF using the same method and then applied 3×10(6) ADSCs to the defect area. At eight weeks post-operation, the subjects were sacrificed, and the distal femoral joint surfaces were evaluated histopathologically for chondral healing. The samples were scored according to the International Cartilage Repair Society (ICRS) scale., Results: The results for group C were significantly better than those for group A in terms of the surface properties (p=0.003). The matrix evaluation was better for group A than for group C (p=0.01). The cell distribution, cell viability and subchondral bone parameters were similar between the groups (p=0.198, p=0.387 and p=0.699). The cartilage mineralization parameter was better for group C than for group A (p=0.001). The signs of healing were better for group C than for group B, but the differences were not significant (p=0.185)., Conclusions: Improvements with additional ADSC treatments were not statistically significant in cases in which ADSC treatment was compared with isolated MF treatment., Clinical Relevance: Additional ADSCs treatment may have positive effect on chondral healing but it doesn't seem significant., (Copyright © 2015 Elsevier B.V. All rights reserved.)

It is hypothesized that microwear traces in natural tooth enamel can be simulated and quantified using microindentation mechanics. Microcontacts associated with particulates in the oral wear medium are modeled as sharp indenters with fixed semi-apical angle. Distinction is made between markings from static contacts (pits) and translational contacts (scratches). Relations for the forces required to produce contacts of given dimensions are derived, with particle angularity and compliance specifically taken into account so as to distinguish between different abrasives in food sources. Images of patterns made on human enamel with sharp indenters in axial and sliding loading are correlated with theoretical predictions. Special attention is given to threshold conditions for transition from a microplasticity to a microcracking mode, corresponding to mild and severe wear domains. It is demonstrated that the typical microwear trace is generated at loads on the order of 1N - i.e. much less than the forces exerted in normal biting - attesting to the susceptibility of teeth to wear in everyday mastication, especially in diets with sharp, hard and large inclusive intrinsic or extraneous particulates., (Published by Elsevier Ltd.)

Treatment of patellofemoral chondral defects is fraught with difficulty because of the generally inferior outcomes and significant biomechanical complexity of the joint. Noyes and Barber-Westin38 performed a systematic review of large (>4 cm2) patellofemoral ACI (11 studies), PFA (5 studies), and osteochondral allografting (2 studies) in patients younger than 50 years. Respectively, failures or poor outcomes were noted in 8% to 60% after ACI, 22% after PFA, and 53% after osteochondral allograft treatment. As noted in the outcome reviews earlier, unacceptable complication and reoperation rates were reported from all 3 procedures, and it was concluded that each operation had unpredictable results for this patient demographic. This study highlights the importance of strict indications and working to address all concomitant diseases to decrease revision rate. Outcomes are most predictable in young patients with low BMI and unipolar defects lower than 4 cm2., (Copyright © 2014 Elsevier Inc. All rights reserved.)