PHB/CHIT Scaffold as a Promising Biopolymer in the Treatment of Osteochondral Defects—An Experimental Animal Study

Biopolymer composites allow the creation of an optimal environment for the regeneration of chondral and osteochondral defects of articular cartilage, where natural regeneration potential is limited. In this experimental study, we used the sheep animal model for the creation of knee cartilage defects. In the medial part of the trochlea and on the medial condyle of the femur, we created artificial defects (6 × 3 mm2) with microfractures. In four experimental sheep, both defects were subsequently filled with the porous acellular polyhydroxybutyrate/chitosan (PHB/CHIT)-based implant. Two sheep had untreated defects. We evaluated the quality of the newly formed tissue in the femoral trochlea defect site using imaging (X-ray, Computer Tomography (CT), Magnetic Resonance Imaging (MRI)), macroscopic, and histological methods. Macroscopically, the surface of the treated regenerate corresponded to the niveau of the surrounding cartilage. X-ray examination 6 months after the implantation confirmed the restoration of the contour in the subchondral calcified layer and the advanced rate of bone tissue integration. The CT scan revealed a low regenerative potential in the bone zone of the defect compared to the cartilage zone. The percentage change in cartilage density at the defect site was not significantly different to the reference area (0.06–6.4%). MRI examination revealed that the healing osteochondral defect was comparable to the intact cartilage signal on the surface of the defect. Hyaline-like cartilage was observed in most of the treated animals, except for one, where the defect was repaired with fibrocartilage. Thus, the acellular, chitosan-based biomaterial is a promising biopolymer composite for the treatment of chondral and osteochondral defects of traumatic character. It has potential for further clinical testing in the orthopedic field, primarily with the combination of supporting factors.

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Prospective Outcomes of Cryopreserved Osteochondral Allograft for Patellofemoral Cartilage Defects at Minimum 2-Year Follow-up

Cartilage ◽

10.1177/1947603520903420 ◽

2020 ◽

pp. 194760352090342

Author(s):

Heath P. Melugin ◽

Taylor J. Ridley ◽

Christopher D. Bernard ◽

Dillen Wischmeier ◽

Jack Farr ◽

...

Keyword(s):

International Knee Documentation Committee ◽

Reoperation Rate ◽

Activity Level ◽

Osteochondral Allograft ◽

Cartilage Defects ◽

Femoral Trochlea ◽

Second Look ◽

Magnetic Resonance Imaging Mri ◽

Tegner Activity Scale

Objective To analyze the clinical outcomes, knee function, and activity level of patients after treatment of full-thickness cartilage defects involving the patellofemoral compartment of the knee with cryopreserved osteochondral allograft. Design Nineteen patients with cartilage defects involving the patellofemoral compartment were treated. The average age was 31 years (range 15-45 years), including 12 females and 7 males. Patients were prospectively followed using validated clinical outcome measures including Veterans RAND 12-item Health Survey (VR-12), International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner activity scale. Graft incorporation was evaluated by magnetic resonance imaging (MRI) or second-look arthroscopy. Results The cartilage defects included the patella ( n = 16) and the femoral trochlea ( n = 3). Mean VR-12 scores increased from 31.6 to 46.3 ( P < 0.01), mean IKDC increased from 40.0 to 69.7 ( P < 0.01), mean KOOS increased from 53.9 to 80.2 ( P < 0.01), and mean Tegner scores increased from 3.0 to 4.9 ( P < 0.01), at average follow-up of 41.9 months (range 24-62 months). Of the 3 patients who underwent second-look arthroscopy, all demonstrated a well-incorporated graft. Mean MOCART score for the 6 patients with follow-up MRI was 62.5 (range 25-85). The reoperation rate was 21.1% and 2 patients (12.5%) experienced progressive patellofemoral osteoarthritis requiring conversion to patellofemoral arthroplasty. Conclusion Patients with unipolar cartilage defects involving the patellofemoral compartment of the knee can have positive outcomes at minimum 2-year follow-up after surgical treatment with a cryopreserved osteochondral allograft when concomitant pathology is also addressed, but the reoperation rate is high and bipolar cartilage lesions may increase the failure rate.

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Transplantation of Aggregates of Autologous Synovial Mesenchymal Stem Cells for Treatment of Cartilage Defects in the Femoral Condyle and the Femoral Groove in Microminipigs

The American Journal of Sports Medicine ◽

10.1177/0363546519859855 ◽

2019 ◽

Vol 47 (10) ◽

pp. 2338-2347 ◽

Cited By ~ 6

Author(s):

Shimpei Kondo ◽

Yusuke Nakagawa ◽

Mitsuru Mizuno ◽

Kenta Katagiri ◽

Kunikazu Tsuji ◽

...

Keyword(s):

Femoral Condyle ◽

Cartilage Regeneration ◽

Medial Femoral Condyle ◽

Cartilage Defects ◽

Control Group ◽

Osteochondral Defects ◽

Medial Condyle ◽

Femoral Groove ◽

Articular Cartilage Regeneration

Background: Previous work has demonstrated that patients with cartilage defects of the knee benefit from arthroscopic transplantation of autologous synovial mesenchymal stem cells (MSCs) in terms of magnetic resonance imaging (MRI), qualitative histologic findings, and Lysholm score. However, the effectiveness was limited by the number of cells obtained, so large-sized defects (>500 mm2) were not investigated. The use of MSC aggregates may enable treatment of larger defects by increasing the number of MSCs adhering to the cartilage defect. Purpose: To investigate whether transplantation of aggregates of autologous synovial MSCs with 2-step surgery could promote articular cartilage regeneration in microminipig osteochondral defects. Study Design: Controlled laboratory study. Methods: Synovial MSCs derived from a microminipig were examined for in vitro colony-forming and multidifferentiation abilities. An aggregate of 250,000 synovial MSCs was formed with hanging drop culture, and 16 aggregates (for each defect) were implanted on both osteochondral defects (6 × 6 × 1.5 mm) created in the medial femoral condyle and femoral groove (MSC group). The defects in the contralateral knee were left empty (control group). The knee joints were evaluated at 4 and 12 weeks by macroscopic findings and histology. MRI T1rho mapping images were acquired at 12 weeks. For cell tracking, synovial MSCs were labeled with ferucarbotran before aggregate formation and were observed with MRI at 1 week. Results: Synovial MSCs showed in vitro colony-forming and multidifferentiation abilities. Regenerative cartilage formation was significantly better in the MSC group than in the control group, as indicated by International Cartilage Repair Society score (macro), modified Wakitani score (histology), and T1rho mapping (biochemical MRI) in the medial condyle at 12 weeks. Implanted cells, labeled with ferucarbotran, were observed in the osteochondral defects at 1 week with MRI. No significant difference was noted in the modified Wakitani score at 4 weeks in the medial condyle and at 4 and 12 weeks in the femoral groove. Conclusion: Transplantation of autologous synovial MSC aggregates promoted articular cartilage regeneration at the medial femoral condyle at 12 weeks in microminipigs. Clinical Relevance: Aggregates of autologous synovial MSCs could expand the indications for cartilage repair with synovial MSCs.

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Classification of Shoulder X-ray Images with Deep Learning Ensemble Models

Applied Sciences ◽

10.3390/app11062723 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2723

Author(s):

Fatih Uysal ◽

Fırat Hardalaç ◽

Ozan Peker ◽

Tolga Tolunay ◽

Nil Tokgöz

Keyword(s):

Deep Learning ◽

Performance Test ◽

The Body ◽

Test Accuracy ◽

Cohen’S Kappa ◽

X Ray ◽

Cohen's Kappa ◽

Auc Value ◽

Magnetic Resonance Imaging Mri ◽

Fully Connected

Fractures occur in the shoulder area, which has a wider range of motion than other joints in the body, for various reasons. To diagnose these fractures, data gathered from X-radiation (X-ray), magnetic resonance imaging (MRI), or computed tomography (CT) are used. This study aims to help physicians by classifying shoulder images taken from X-ray devices as fracture/non-fracture with artificial intelligence. For this purpose, the performances of 26 deep learning-based pre-trained models in the detection of shoulder fractures were evaluated on the musculoskeletal radiographs (MURA) dataset, and two ensemble learning models (EL1 and EL2) were developed. The pre-trained models used are ResNet, ResNeXt, DenseNet, VGG, Inception, MobileNet, and their spinal fully connected (Spinal FC) versions. In the EL1 and EL2 models developed using pre-trained models with the best performance, test accuracy was 0.8455, 0.8472, Cohen’s kappa was 0.6907, 0.6942 and the area that was related with fracture class under the receiver operating characteristic (ROC) curve (AUC) was 0.8862, 0.8695. As a result of 28 different classifications in total, the highest test accuracy and Cohen’s kappa values were obtained in the EL2 model, and the highest AUC value was obtained in the EL1 model.

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Is intervertebral disc degeneration related to segmental instability? An evaluation with two different grading systems based on clinical imaging

Acta Radiologica ◽

10.1177/0284185117715284 ◽

2017 ◽

Vol 59 (3) ◽

pp. 327-335 ◽

Cited By ~ 3

Author(s):

David Volkheimer ◽

Fabio Galbusera ◽

Christian Liebsch ◽

Sabine Schlegel ◽

Friederike Rohlmann ◽

...

Keyword(s):

Intervertebral Disc Degeneration ◽

Statistical Significance ◽

Axial Rotation ◽

Spinal Motion ◽

X Ray ◽

Grading Systems ◽

Flexion Extension ◽

The Difference ◽

Magnetic Resonance Imaging Mri

Background Several in vitro studies investigated how degeneration affects spinal motion. However, no consensus has emerged from these studies. Purpose To investigate how degeneration grading systems influence the kinematic output of spinal specimens. Material and Methods Flexibility testing was performed with ten human T12-S1 specimens. Degeneration was graded using two different classifications, one based on X-ray and the other one on magnetic resonance imaging (MRI). Intersegmental rotation (expressed by range of motion [ROM] and neutral zone [NZ]) was determined in all principal motion directions. Further, shear translation was measured during flexion/extension motion. Results The X-ray grading system yielded systematically lesser degeneration. In flexion/extension, only small differences in ROM and NZ were found between moderately degenerated motion segments, with only NZ for the MRI grading reaching statistical significance. In axial rotation, a significant increase in NZ for moderately degenerated segments was found for both grading systems, whereas the difference in ROM was significant only for the MRI scheme. Generally, the relative increases were more pronounced for the MRI classification compared to the X-ray grading scheme. In lateral bending, only relatively small differences between the degeneration groups were found. When evaluating shear translations, a non-significant increase was found for moderately degenerated segments. Motion segment segments tended to regain stability as degeneration progressed without reaching the level of statistical significance. Conclusion We found a fair agreement between the grading schemes which, nonetheless, yielded similar degeneration-related effects on intersegmental kinematics. However, as the trends were more pronounced using the Pfirrmann classification, this grading scheme appears superior for degeneration assessment.

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Experience of Using Hyperbaric Oxygenation in the Treatment of Radionecrosis That Developed as a Complication of Stereotactic Radiosurgical Treatment of Meningioma on the Example of a Clinical Case

Russian Sklifosovsky Journal Emergency Medical Care ◽

10.23934/2223-9022-2020-9-4-670-676 ◽

2021 ◽

Vol 9 (4) ◽

pp. 670-676

Author(s):

A. S. Tokarev ◽

V. N. Stepanov ◽

V. A. Rak ◽

O. L. Yevdokimova ◽

I. A. Terekhin ◽

...

Keyword(s):

Clinical Picture ◽

Hyperbaric Oxygenation ◽

Radiation Necrosis ◽

Late Complication ◽

Intravenous Contrast ◽

X Ray ◽

Combined Use ◽

Radiation Induced ◽

Magnetic Resonance Imaging Mri ◽

And Control

In contrast to conventional microsurgery, stereotactic radiosurgery has an advantage in the treatment of intracranial masses, avoiding severe complications associated with open surgery. In rare cases, the use of the method is associated with the development of radiation-induced injuries, one of which is radiation necrosis (RN). This is a late complication of radiosurgery, developing mainly 6 months after radiation exposure. The neurological manifestations of this complication depend on location, and the clinical picture is very diverse. The method of magnetic resonance imaging (MRI) with intravenous contrast enhancement is quite often the first link in neuroimaging, which helps to suggest the presence of this complication based on the X-ray picture and to clarify the location of changes.We presented the experience of radiation necrosis treatment in a 47-year-old patient who was referred to our department with a diagnosis of frontal meningioma. The patient underwent stereotactic radiosurgical treatment using the Elekta Leksell Gamma Knife Perfextion device, and 6 months later the gradual deterioration began, the patient complained of headache, nausea; central prosoparesis developed. Considering the clinical picture and control MRI data, the changes were interpreted as radionecrosis. In order to control the complication, the patient underwent standard glucocroticosteroid therapy, supplemented by hyperbaric oxygenation (HBO), which made it possible to achieve regression of the adverse clinical and radiological manifestations of the complication. Thus, on a clinical example, it was demonstrated that the combined use of glucocorticosteroids and HBOs is highly effective in the treatment of RN.

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The Assessment of the Condition of Knee Joint Surfaces with Acoustic Emission Analysis

Sensors ◽

10.3390/s21196495 ◽

2021 ◽

Vol 21 (19) ◽

pp. 6495

Author(s):

Bartłomiej Sawaryn ◽

Natalia Piaseczna ◽

Szymon Sieciński ◽

Rafał Doniec ◽

Konrad Duraj ◽

...

Keyword(s):

Knee Joint ◽

Knee Injury ◽

Knee Joints ◽

Resonance Imaging ◽

Emission Analysis ◽

X Ray ◽

Joint Surfaces ◽

Magnetic Resonance Imaging Mri ◽

Leg Movements ◽

Acoustic Emission Analysis

The knee joint, being the largest joint in the human body, is responsible for a great percentage of leg movements. The diagnosis of the state of knee joints is usually based on X-ray scan, ultrasound imaging, computerized tomography (CT), magnetic resonance imaging (MRI), or arthroscopy. In this study, we aimed to create an inexpensive, portable device for recording the sound produced by the knee joint, and a dedicated application for its analysis. During the study, we examined fourteen volunteers of different ages, including those who had a knee injury. The device effectively enables the recording of the sounds produced by the knee joint, and the spectral analysis used in the application proved its reliability in evaluating the knee joint condition.

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Characterization and genesis of horizontal banding in Brazilian agate: an X-ray diffraction, thermogravimetric and electron microprobe study

Mineralogical Magazine ◽

10.1180/minmag.2013.077.3.02 ◽

2013 ◽

Vol 77 (3) ◽

pp. 227-248 ◽

Cited By ~ 10

Author(s):

T. Moxon ◽

C. M. Petrone ◽

S. J. B. Reed

Keyword(s):

Amorphous Silica ◽

Electron Microprobe ◽

X Ray Diffraction ◽

X Ray ◽

Wall Lining ◽

Defect Site ◽

Site Water ◽

Stage Process ◽

Upper Chamber

AbstractCharacterization of Brazilian agates containing a lower horizontally banded section and an upper chamber with bands parallel to the walls shows that these agates formed much later than the 135 Ma Paraná basalt host rock. Age differentiation between the two types of banding shows that the horizontal bands formed between 43 to 63 Ma ago with a final infill of wall-lining bands between 7 and 27 Ma later. The horizontal bands have a higher Al3+ concentration and a greater crystallite size than the wall-lining layers; they have a lower mogánite content and defect-site water content. The formation of these agates appears to be the result of a three-stage process. After the separate formation of horizontally banded and wall-lining agate, a silica infill seals the gap between the agate and the cavity wall. The detection of cristobalite in some specimens indicates that genesis of both the horizontally banded and wall-lining deposits in the Brazilian samples proceeds along an amorphous silica → opal-CT → opal-C → chalcedony pathway.

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Magnetic Resonance Imaging to Investigate the Clinical Applicability of the Medial Femoral Trochlea Osteochondral Flap Within the Wrist

Hand ◽

10.1177/15589447211064363 ◽

2022 ◽

pp. 155894472110643

Author(s):

Jimmy H. Daruwalla ◽

Jan Skrok ◽

Mitchell A. Pet ◽

Aviram M. Giladi ◽

James P. Higgins

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Sagittal Plane ◽

Convex Surface ◽

Radius Of Curvature ◽

Resonance Imaging ◽

Femoral Trochlea ◽

Average Ratio ◽

Mri Scans ◽

Magnetic Resonance Imaging Mri

Background: The medial femoral trochlea (MFT) osteochondral flap is employed for reconstruction of unsalvageable scaphoid proximal pole nonunions. The convex surface of the cartilage-bearing proximal trochlea is used to replace the similarly contoured proximal scaphoid and articulate with the concave scaphoid fossa of the radius. A magnetic resonance imaging (MRI) comparison of the shape of the MFT as it relates to the native proximal scaphoid has not been previously performed. Our study aimed to quantifiably compare the shape of the MFT, proximal scaphoid, and scaphoid fossa. Methods: Using imaging processing software, we measured radius of curvature of the articular segments in MRI scans of 10 healthy subjects’ wrists and knees. Results: Compared with the scaphoid fossa, average ratio of the radius of circumference of the proximal scaphoid was 0.79 and 0.78 in the coronal and sagittal planes, respectively. Compared with the scaphoid fossa, average ratio of the radius of circumference of the MFT was 0.98 and 1.31 in the coronal and sagittal planes, respectively. The radius of curvature of the MFT was larger than the proximal scaphoid, in the coronal and sagittal planes. In the coronal plane, the MFT radius of curvature is nearly identical to the scaphoid fossa, a closer match than the scaphoid itself. In the sagittal plane, the radius of curvature of the MFT was larger than the radius of curvature of the scaphoid fossa. Conclusions: Our data suggest that the radius of curvature, in the sagittal and coronal planes, of the MFT and proximal scaphoid is disparate.

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The Use of Particulated Juvenile Allograft Cartilage for the Repair of Porcine Articular Cartilage Defects

The American Journal of Sports Medicine ◽

10.1177/0363546519856346 ◽

2019 ◽

Vol 47 (10) ◽

pp. 2308-2315 ◽

Cited By ~ 6

Author(s):

Yunong Ao ◽

Zhong Li ◽

Qi You ◽

Chengchang Zhang ◽

Liu Yang ◽

...

Keyword(s):

Articular Cartilage ◽

Statistical Difference ◽

Fibrous Tissue ◽

Cartilage Defects ◽

Control Group ◽

General View ◽

Full Thickness ◽

Femoral Trochlea ◽

Articular Cartilage Defects ◽

Experimental Group

Background: The repair of porcine articular cartilage defects by using particulated juvenile allograft cartilage (PJAC) has demonstrated good short-term clinical efficacy, but the repair process and mechanism have not been fully elucidated. Purpose: To study the efficacy of PJAC in repairing full-thickness cartilage defects and to provide an experimental basis for its clinical application. Study Design: Controlled laboratory study. Methods: Thirty Guizhou minipigs were randomly divided into an experimental group and control group. An 8-mm cylindrical full-thickness cartilage defect was created in the femoral trochlea of either knee in all minipigs. The experimental group received the PJAC transplantation (PJAC group; n = 15) and the control group received autologous cartilage chips (ACC group; n = 15). Five minipigs were euthanized at 1, 3, and 6 months in each group to obtain samples, which were evaluated by general view of the knee joint and histomorphometry of the chondral defect area (hematoxylin and eosin, safranin O). International Cartilage Repair Society (ICRS) II semiquantitative evaluation and collagen type II staining immunohistochemistry were also performed. Results: All 30 Guizhou minipigs were followed; there was no infection or incision healing disorder after the operation. At 1 month postoperatively, more hyaline cartilage was found in the ACC group (29.4%) compared with the PJAC group (20.1%) ( P < .05); there was no statistical difference between the 2 groups at 3 and 6 months after operation. The fibrocartilage content in the ACC group was significantly more than that in the PJAC group at 1 and 3 months postoperatively (27.4% vs 18.2% and 49.9% vs 41.1%, respectively; P < .05); significant differences disappeared at 6 months postoperatively. The PJAC group produced more fibrous tissue than the ACC group at 1 and 3 months postoperatively (60.1% vs 40.6% and 38.8% vs 24.4%, respectively; P < .05) but showed no statistical difference at 6 months postoperatively. Regarding the ICRS II scores, those of the ACC group were significantly better than the scores of the PJAC group in some subclasses at 3 and 6 months postoperatively. The positive rates of immunohistochemical staining in the ACC group were higher at 1 and 3 months postoperatively than those in the PJAC group (54.2% vs 37.8% and 46.4% vs 34.4%, respectively; P < .05). The difference was not statistically significant between the 2 groups at 6 months postoperatively. Conclusion: Both PJAC and ACC can produce a good repair effect on cartilage defects. At 1 and 3 months postoperatively, ACC resulted in better outcomes than PJAC, but there was no statistical difference in the repair effect between the 2 techniques at 6 months postoperatively. Clinical Relevance: Based on this animal experiment, further clinical studies are needed to investigate PJAC as a possible alternative first-line treatment for cartilage defects.

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Uniform line focus and multitarget coupling for the creation of near-water-window nickel-like x-ray laser

10.1117/12.375120 ◽

2000 ◽

Author(s):

Huajing Tang ◽

Hiroyuki Daido ◽

Stephane Sebban ◽

Y. Takagi ◽

Kunioki Mima ◽

...

Keyword(s):

X Ray ◽

Water Window ◽

The Creation ◽

Line Focus

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