Search

Copyright of Die Orthopädie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The aim of this study is to compare preoperative and postoperative clinical and radiological findings of patients with talus osteochondral lesion who underwent arthroscopic microfracture surgery. Materials and Methods: Thirty-two patients who underwent arthroscopic treatment for talus osteochondral lesion between 2014-2017 at the Department of Orthopedics and Traumatology of a tertiary hospital were evaluated retrospectively. Preoperative and postoperative AOFAS and VAS scores were recorded, and the results were compared with demographic data. Twenty-four patients with magnetic resonance imaging were evaluated with the MOCART system. Results were compared with AOFAS, VAS scores, and demographic data. Results: Of the 32 patients included in the study, 13 (40.6%) were male, and 19 (59.4%) were female. The mean body mass index (BMI) of the patients was 26.1 kg/m². In 14 (43.8%) patients, there was a history of trauma. The number of smokers was 12 (37.5%). Twelve (37.5%) patients had a BMI=25 kg/m², and 20 (62.5%) patients had a BMI>25 kg/m². The mean age of the patients was 42.62 years. The mean follow-up period was 20.9 months. The mean MOCART value of the patients with MRI after surgery was 56.11. Conclusion: It was found that there was no correlation between cartilage healing detected with MRI and clinical improvement, function, and patient satisfaction. The body mass indexes of the patients and smoking did not have a significant effect on the results. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the surgical outcomes of arthroscopic pull-out repair for medial meniscus root tear (MMRT) combined with the marrow stimulation procedures (MSP) for accompanying high-grade cartilage lesions. Methods: Patients who underwent arthroscopic pull-out repair for MMRT between 2010 and 2019 were retrospectively reviewed. Patients who had at least 3 years of follow-up were included and classified into two groups according to whether MSP (microfracture or microdrilling) were performed on cartilage lesions in the medial tibiofemoral joint (group 1, patients with International Cartilage Repair Society [ICRS] grade 0–3a lesions and did not undergo MSP; group 2, patients with ICRS grade 3b–3d lesions and underwent MSP). Comparative analyses, including non-inferiority trials, were conducted between groups for subjective and objective outcomes. In addition, group 2 was further divided into two subgroups according to cartilage lesion size and compared with group 1 (group S, ≤ 2.0 cm2; group L, > 2.0 cm2). Results: A total of 94 patients were included (group 1, 68 patients; group 2, 26 patients). There were no significant differences in clinical scores at postoperative 3 years and final follow-up between groups 1 and 2, but group 2 failed to satisfy the non-inferiority criteria compared to group 1 overall. In objective outcomes, group 2 did not meet the non-inferiority criteria for the rate of osteoarthritis progression compared to group 1, and it also showed a significantly higher proportion of high-grade osteoarthritis at final follow-up (P = 0.044) and a higher degree of osteoarthritis progression than group 1 (P = 0.03 for pre- to postoperative 3 years, and P = 0.006 for pre- to final follow-up). In additional evaluations comparing the subgroups of group 2 and group 1, group S showed relatively favourable results compared to group L in objective outcomes at final follow-up. Conclusion: Patients who underwent arthroscopic pull-out repair for MMRT combined with MSP for accompanying high-grade cartilage lesions showed suboptimal outcomes compared to those with no or low-grade lesions at mid-term follow-up. High-grade cartilage lesions ≤ 2.0 cm2 may be candidates for the surgical repair of MMRT if MSP are performed, but those with larger lesions may require alternative treatment strategies. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study is to investigate and compare the effects of biological adjuvants (platelet-rich plasma, platelet-rich fibrin matrix) and microfracture technique individually and in combination on full thickness chondral defects in a rabbit model. Methods: A total of 60 New Zealand White rabbits were randomly divided into six groups according to treatment modality as follows: control (C), microfracture (MF), platelet-rich plasma (PRP), platelet-rich fibrin matrix (PRFM), platelet-rich fibrin matrix after microfracture (MF + PRFM) and platelet-rich plasma after microfracture (MF + PRP) groups. The cartilage repair tissue was assessed histologically via International Cartilage Repair Score (ICRS) and macroscopically via ICRS macroscopic assessment scale. Results: It was shown that overall macroscopic scores of the groups with MF were higher than those of the groups without MF. The cell morphology observed in the defect areas was mostly characterized with non-chondrocyte cells in the groups without MF, whereas chondrocyte cells mostly prevailed in the groups with MF. There was a greater integration through the cartilage-like tissue in the MF + PRP and MF + PRFM groups. The control group showed either fissures or fissures partially filled with fibrous tissue. When the groups were individually examined, there were statistically significant differences between the control and MF groups (p = 0.002), between the control and MF + PRFM groups (p = 0.001), between the control and MF + PRP groups (p < 0.001), between the PRFM and MF + PRFM groups (p = 0.014) and between the PRFM and MF + PRP (p = 0.023) groups in terms of histological evaluation scores. Conclusion: The application of PRP and PRFM in combination with MF treatment exhibited a positive impact on the repair and restoration of cartilage, and produced better outcomes than the individual use of PRP and PRFM. Nevertheless, in the treatment of full thickness chondral defects, the use of PRFM injection is recommended, which is performed intraoperatively at a single time and with no difficulty of repeating after surgery, instead of serial PRP injections based on the macroscopic and histological results obtained in the present study indicating that there was no significant difference between the use of these two adjuvants. [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.

BACKGROUND: The reduction of mechanical bearing capacity of the femoral head is the main cause of femoral head collapse, and cystic degeneration affects the normal mechanical conduction pathway of the hip joint. However, few studies have explored the relationship between the two in the development of femoral head necrosis. OBJECTIVE: To discuss the distribution law and pathological characteristics of cystic degeneration in steroid-induced femoral head necrosis based on heat map model and pathological results. METHODS: Thirty patients (30 hips) who were diagnosed with steroid-induced femoral head necrosis in the Third Affiliated Hospital of Guangzhou University of Chinese Medicine from June to December 2021 were selected as the research objects, and the outline of cystic degeneration of steroid-induced femoral head necrosis was extracted and the contour line was matched to the standard femoral head model to present the contour line as a heat map. Necrosis position and necrosis area of the femoral head were recorded and counted to study the relationship between the two. Hematoxylin-eosin staining was used for histomorphological changes of femoral head specimens. RESULTS AND CONCLUSION: (1) Based on the heat map of the cystic degeneration of steroid-induced femoral head necrosis and the pathological results of the femoral head, we found that cystic degeneration commonly occurred in the medial and lateral columns of the femoral head after steroid-induced femoral head necrosis. Compared with the area of cystic degeneration of the medial column, the area of cystic degeneration of the lateral column was larger, and with the inward movement of cystic degeneration, its area also decreased. (2) In addition, microfracture lines were scattered around cystic degeneration, which may be one of the important factors affecting the mechanical bearing capacity and stability of the femoral head. [ABSTRACT FROM AUTHOR]

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]

Background: Microfracture is the most common treatment for cartilage defects of the knee. In microfracture surgery, holes are randomly drilled into the subchondral bone. The effect of the hole's location on its interaction with the cartilage defect site and its influence on the healing process is currently uncertain. Purpose: To investigate the effects of different microfracture locations on healing in a rabbit knee osteochondral defect model. Study Design: Controlled laboratory study. Methods: A total of 29 adult New Zealand White rabbits were divided into 5 groups. In the healthy cartilage control group (n = 5), no surgical procedure was performed. Cylindrical full-thickness cartilage defects (5 × 3 mm) were created in the patellar groove of the remaining 24 rabbits. In the defect control group (n = 6), only the defect was created. A microfracture was performed at the 12-o'clock position (group peripheral single; n = 6), centrally (group central; n = 6), and at the 12- and 6-o'clock positions (group peripheral double; n = 6) of the defect. The animals were sacrificed after 8 weeks. Cartilage healing was evaluated by International Cartilage Regeneration & Joint Preservation Society (ICRS) score, modified O'Driscoll score, immunohistochemical analysis (type 1 collagen, type 2 collagen, and aggrecan), and scanning electron microscopy analysis. Results: In group peripheral double, better cartilage healing was observed in all parameters compared with the other groups (P <.05). Group peripheral double had the greatest amount of filling, with 79% of the defect area filled with fibrocartilage repair tissue. Group peripheral single demonstrated filling of 73% of the defect area, group central 56%, and the defect control group 45%. The ICRS score was significantly higher in group peripheral single compared with group central and the defect control group. Type 2 collagen and aggrecan immunoreactivity were significantly stronger in group central than group peripheral single and the defect control group (P <.05). Conclusion: Microfracture performed at the peripheral margin of the defect had better filling characteristics in a rabbit model. This study suggests that interaction of pluripotent cells released from the microfracture site with the intact cartilage may enhance the quality of the repair tissue. Clinical Relevance: The location of microfracture holes in relation to the peripheral border of the osteochondral defect (to the intact cartilage) is important in both the quality and the quantity of the newly formed repair tissue. [ABSTRACT FROM AUTHOR]

Background: Microfracture at the rotator cuff insertion is an established surgical marrow-stimulation technique for enhancing rotator cuff healing. However, the effect of lateralized or medialized microfracture on the insertion is unknown. Purpose: To compare the biomechanical and histologic effects of microfracture at 3 different regions for rotator cuff repair in a rat model. Study Design: Controlled laboratory study. Methods: A total of 72 Sprague-Dawley rats with bilateral supraspinatus tendon insertion detachment were allocated into 4 groups with 4 different interventions: no microfracture at the humeral head as a control group (Con), traditional microfracture at the footprint area (MFA), and medialized microfracture to the footprint area (MMFA) on the articular surface of the humerus or lateralized microfracture to the footprint area at the greater tuberosity (LMFA). All underwent immediate repair. Tendon-to-bone healing was assessed by biomechanical and histologic tests 4 and 8 weeks postoperation. Results: At 4 weeks, the LMFA group showed a significantly superior failure load compared with the other groups (all P <.05). The LMFA and MFA groups showed significantly superior stiffness compared with the Con and MMFA groups (all P <.01). At 8 weeks, superior failure load and stiffness were observed in the LMFA group compared with the control group (all P <.05). Histologic examination revealed that the LMFA group had superior collagen composition and tendon-to-bone maturation at the interface at 4 and 8 weeks compared with the Con group (all P <.05). Conclusion: Lateralized microfracture at the greater tuberosity improved the histologic quality of repair tissue and biomechanical strength at the tendon-to-bone insertion after rotator cuff repair in a rat model. Clinical Relevance: Microfracture lateral to the footprint area might be a better way to enhance rotator cuff healing clinically. [ABSTRACT FROM AUTHOR]

To determine whether intraarticular viscosupplementation and arthroscopic debridement can delay knee arthroplasty. 142 patients who had VAS and OX-12 records from the first visit and regular control visit and who belonged to the control group who were referred to our clinic with pain and limitation of movement in the knee diagnosed with primary osteoarthritis of the knee Grade 2-3 according to the Kellgren-Lawrence Classification (KLC) and were followed up for at least 5 years (6,7 ±1,4 years) were included in the study. Of the 142 patients, 87 (61,3 %) were female and 55 (38,3%) were male. The average age of the patients was 53,2 ± 14,3. The groups were compared for average age on first admission, gender, the existance of morbid obesity and diabetes, average Visual Pain Score (VPS), and Oxford-12 Questionary (OX-12) scores, and smoking. Time between the first admission and arthroplasty was also compared. Arthroplasty was performed in 87 (61,3%) of the 142 patients in 6,7±1,4. In the control group, which consisted of patients taking only NSAIDs, patients who were given viscosupplementation and patients who underwent arthroscopic debridement, the rate of total knee arthroplasty was 61,5%, 60,4%, and 61,9%, respectively. We determined that despite an improvement in clinical symptoms like pain between the sixth month and the second year, viscosupplementation and arthroscopic debridement do not ameliorate the degenerative process and radiologic deterioration and do not affect on the duration until total knee arthroplasty. [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]

Background: Full-thickness acetabular cartilage lesions are common findings during primary surgical treatment of femoroacetabular impingement (FAI). Purpose: To evaluate clinical outcomes after acetabular microfracture performed during FAI surgery in a prospective, multicenter cohort. Study Design: Cohort Study; Level of evidence, 3. Methods: Patients with FAI who had failed nonoperative management were prospectively enrolled in a multicenter cohort. Preoperative and postoperative (mean follow-up, 4.3 years) patient-reported outcome measures were obtained with a follow-up rate of 81.6% (621/761 hips), including 54 patients who underwent acetabular microfracture. Patient characteristics, radiographic parameters, intraoperative disease severity, and operative procedures were analyzed. Propensity matching using linear regression was used to match 54 hips with microfracture to 162 control hips (1:3) to control for confounding variables. Subanalyses of hips ≤35 and >35 years of age with propensity matching were also performed. Results: Patients who underwent acetabular microfracture were more likely to be male (81.8% vs 40.9%; P <.001), be older in age (35.0 vs 29.9 years; P =.001), have a higher body mass index (27.2 vs 25.0; P =.001), and have a greater alpha angle (69.6° vs 62.3°; P <.001) compared with the nonmicrofracture cohort (n = 533). After propensity matching to control for covariates, patients treated with microfracture displayed no differences in the modified Harris Hip Score or Hip Disability and Osteoarthritis Outcome Score (P =.22-.95) but were more likely to undergo total hip arthroplasty (THA) (13% [7/54] compared with 4% [6/162] in the control group; P =.002), and age >35 years was associated with conversion to THA after microfracture. Microfracture performed at or before 35 years of age portended good outcomes with no significant risk of conversion to THA at the most recent follow-up. Conclusion: Microfracture of acetabular cartilage defects appears to be safe and associated with reliably improved short- to mid-term results in younger patients; modified expectations should be realized when full-thickness chondral lesions are identified in patients >35 years of age. [ABSTRACT FROM AUTHOR]

Background: Microfracture (MF) is frequently performed as a first-line treatment for articular cartilage defects. Although good clinical outcomes are often obtained in the short term, poor clinical outcomes sometimes occur because of subchondral bone deterioration. The condition of the subchondral bone treated with MF may affect the repair of the osteochondral unit. Purpose: To analyze histological findings of the osteochondral unit after performing MF on subchondral bone in different states—normal, absorption, and sclerosis—in a rat model. Study Design: Controlled laboratory study. Methods: Full-thickness cartilage defects (5.0 × 3.0 mm) were created in the weightbearing area of the medial femoral condyle in both knees of 47 Sprague-Dawley rats. Five MF holes were created within the cartilage defect using a 0.55-mm needle to a depth of 1 mm at 0 weeks (normal group), 2 weeks (absorption group), and 4 weeks (sclerosis group) after the cartilage defect was created. In the left knee, MF holes were filled with β-tricalcium phosphate (β-TCP). At 2 and 4 weeks after MF, knee joints were harvested and histologically analyzed. Results: MF holes were enlarged at 2 weeks and further enlarged at 4 weeks in all groups. In the absorption group, osteoclast accumulation around the MF holes and cyst formation were observed. The trabecular bone surrounding the MF holes was thickened in the sclerosis group. The diameter of the MF hole was largest in the absorption group at 2 and 4 weeks after MF compared with the other groups. No subchondral bone cysts were observed after β-TCP implantation. Pineda scores in all groups were significantly better with β-TCP implantation than without β-TCP implantation at 2 and 4 weeks. Conclusion: MF for subchondral bone with bone absorption induced enlargement of the MF holes, cyst formation, and delay of cartilage defect coverage. Implantation of β-TCP into the MF holes enhanced remodeling of the MF holes and improved repair of the osteochondral unit compared with MF only. Therefore, the condition of the subchondral bone treated with MF affects repair of the osteochondral unit in a cartilage defect. [ABSTRACT FROM AUTHOR]

Background: Focal cartilage lesions represent a common source of knee pain and disability, with the potential for the development and progression of osteoarthritis. Currently, microfracture (MFx) represents the most utilized first–line surgical treatment for small, focal chondral lesions. Recent investigations have examined methods of overcoming the limitations of MFx utilizing various augmentation techniques. Purpose: To perform a systematic review and meta–analysis evaluating clinical and radiographic outcomes in patients undergoing isolated MFx versus MFx augmented with orthobiologics or scaffolds for focal chondral defects of the knee. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A systematic review was performed to identify studies evaluating outcomes and adverse events in patients undergoing isolated MFx versus augmented MFx for focal chondral defects in the knee from 1945 to June 1, 2021. Data were extracted from each article that met the inclusion/exclusion criteria. Meta-analyses were performed for all outcomes reported in a minimum of 3 studies. Results: A total of 14 studies were identified, utilizing 7 different types of injectable augmentation regimens and 5 different scaffolding regimens. Across the 14 studies, a total of 744 patients were included. The mean patient age was 46.8 years (range, 34-58 years), and 58.3% (n = 434/744) of patients were women. The mean final follow–up time was 26.7 months (range, 12-60 months). The mean chondral defect size ranged from 1.3 to 4.8 cm2. A post hoc analysis comparing mean improvement in postoperative outcomes scores compared with preoperative values found no significant differences in the improvement in the visual analog scale (VAS), International Knee Documentation Committee (IKDC), or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores between patients undergoing isolated MFx and those undergoing MFx + augmentation. Patients undergoing MFx + augmentation reported significantly greater improvements in the Lysholm score and postoperative MOCART (magnetic resonance observation of cartilage repair tissue) scores compared with the isolated MFx group. Conclusion: Patients undergoing combined MFx + augmentation reported significant improvements in mean Lysholm and MOCART scores, without significant improvements in VAS, IKDC, or WOMAC scores when compared with patients undergoing isolated MFx. [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]

Focal cartilage defects in the knee are a common and debilitating pathology. High arthroplasty revision rates in the <55-year-old population continue to make arthroplasty a limited primary surgical option. Advancements in surgical techniques and more robust long-term data on cartilage procedures have increased greatly in the last few years. Results vary and are dependent on matching suitable procedures to lesion and patient type. In this difficult-to-manage group, offering the right procedure to the right patient at the first instance has an important impact on outcomes. In this paper we review the evidence and new guidelines in the management of focal cartilage lesions of the knee. [ABSTRACT FROM AUTHOR]

The surgical treatment of chondral and osteochondral defects within the knee is becoming increasingly more complex and challenging, with an ever-increasing selection of options available to the orthopaedic surgeon. Technological and innovative advancements often move at a greater pace than the associated clinical outcomes and research-based evidence. The treatment for these conditions is continually evolving and developing before it is possible to critically appraise the data on their success. These surgical treatments are either biological, where an attempt is made to regenerate the lost tissue, or non-biological, such as focal resurfacing, partial or total arthroplasty. Each of these treatment modalities has their own merits and drawbacks. Focal resurfacings have been around for a few decades, and their aim is to be the best of both options. While still not part of mainstream practice within the UK, their evidence base is growing, and the National Institute for Health and Care Excellence has issued a review on their use. This review aims to assess the options available for treating cartilage defects in the knee, with a focus on these novel focal resurfacing implants. [ABSTRACT FROM AUTHOR]

Background: Despite increased recognition of coexisting tibial and talar osteochondral lesions (OCLs), the risk factors influencing clinical outcomes remain unclear. Purpose: To report clinical follow-up results after arthroscopic microfracture surgery in patients with OCLs of the distal tibial plafond and talus and assess possible factors affecting these clinical outcomes. Study Design: Case series; Level of evidence, 4. Methods: A total of 40 patients with coexisting talar and tibial OCLs who underwent arthroscopic microfracture surgery were included. For analysis, the study used the American Orthopaedic Foot & Ankle Society (AOFAS) scale, Karlsson-Peterson scale, and visual analog scale (VAS) for pain for clinical evaluations on the day before surgery, 12 months after surgery, and at the last follow-up. A stepwise regression model and Spearman rank correlation were used to assess possible factors affecting these clinical outcomes. Results: The median follow-up time was 34.5 months (interquartile range [IQR], 26.5-54 months). At the final follow-up, the cohort included 40 patients (26 men and 14 women) with a mean age of 38.8 years (range, 19-60 years). The median AOFAS score increased from 57.5 (IQR, 47-65) before surgery to 88 (IQR, 83-92.5) at the final follow-up, the median Karlsson-Peterson score increased from 48 (IQR, 38.5-67) to 82 (IQR, 76-92), and the median VAS score improved from 5 (IQR, 4-6) to 1 (IQR, 0-2). All scale scores showed significant differences between the preoperative and final follow-up evaluations (P <.001). In the stepwise regression model and Spearman rank correlation analysis, the grade of tibial OCL had a significant independent effect on the final postoperative AOFAS scores of the patients (β = –0.502, P =.001; r = –0.456, P =.003). The size of the tibial lesion also had a significant independent effect on the final postoperative Karlsson-Peterson scores of the patients (β = –0.444, P =.004; r = –0.357, P =.024). Conclusion: Arthroscopic microfracture treatment for coexisting talar and tibial OCLs can achieve good short- to midterm clinical outcomes. The grade and size of tibial OCLs are the main risk factors affecting the prognostic functional scores of such patients. [ABSTRACT FROM AUTHOR]

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

China is rich in shale gas resources, however, wellbores in shale gas reservoirs are frequently unstable. This has a serious impact on the shale gas drilling cycle. Polyamine, a common additive in water-based shale drilling fluids, can effectively inhibit shale hydration. However, there is a lack of quantitative research on the effect of polyamine inhibitors on the microstructure and macromechanical properties of shale. Therefore, this study investigated those issues via a systematic hydration experiment carried out on shale from the Longmaxi Formation. The results show that microfractures are created and expand during shale hydration, that they also connect to form a complex microfracture network, and that 3% polyamine inhibitors (polyamine solution with volume fraction of 3%) can effectively inhibit their evolution. The ultrasonic velocities and UCS of the Longmaxi shale are significantly anisotropic; the former first increases and then decreases with the laminae angle, reaching its maximum when the laminae angle is 30°. The UCS of the shale is highest and lowest, respectively, when the laminae angles are 0° or 90° and 30°. In general, these UCS appear as a “U'' pattern, high on two sides with a dip in the center. Polyamines can effectively inhibit both the expansion of shale and the reduction of P-wave and S-wave velocities, the UCS, and elastic modulus. The UCS of a shale sample was reduced by 28%–40% after immersion for 96 h in water, compared to 2%–20% after immersion in a 3% polyamine inhibitor for the same amount of time. The inhibiting effect of the polyamine was remarkable.