Total Meniscus Research Articles

Incidence of symptomatic discoid meniscus in Korea: epidemiologic big data analysis from HIRA database

BackgroundThere is a lack of evidence of the diagnosis and treatment-related epidemiological studies of symptomatic discoid meniscus. This study analyzed the national epidemiological data for discoid meniscus in South Korea.MethodsFrom 2011 to 2019, data related to the diagnosis and procedure codes of discoid meniscus were obtained from the Korean Health Insurance Review and Assessment Service database. All patients encoded as discoid meniscus were included. Data were extracted and further analyzed as follows: (1) the total number and the incidence (cases per 100,000) of discoid meniscus diagnosis per year, (2) sex distribution, (3) age distribution, (4) discoid meniscus ratio (total discoid meniscus coding per total meniscus injury coding), and (5) surgical procedures after discoid meniscus injury.ResultsThe total number of discoid meniscus diagnosed was 4576 in 2011 and increased to 6639 in 2019, representing a 45.1% increase. The incidence was 9.5 in 2011 and increased to 13.0 in 2019. Concerning sex, discoid meniscus was more common in females (55%) than in males (45%) over the study period. Regarding age, the peak age of discoid meniscus in 2011 was “under 19,” whereas in 2019, the peak age was observed in the 50s. The discoid meniscus ratio range was 2.12–2.60% from 2011 to 2019. The total number of meniscectomy increased by 20% from 2000 in 2011 to 2475 in 2014. However, the total number of meniscus repairs was 318 in 2011 and increased to 502 in 2019, indicating an increase of 58%.ConclusionsThe total number and incidence of symptomatic discoid as well as the discoid meniscus ratio and the incidence of total discoid meniscus repair steadily increased from 2011 to 2019. The number of meniscus repair procedures increased more rapidly than that of meniscectomy. The current study helps understand the epidemiology of symptomatic discoid meniscus, its prevention, and cost-saving measures in South Korea.

A state-dependent bimodal soil water retention model considering evolutions of pore-scale soil–water interaction

Existing soil water retention models can capture the effects of void ratio and/or net mean stress on the changes in soil water retention curve (SWRC). However, most of them, especially those for bimodal soil that is composed of macro- and micro-pore systems, do not consider the simultaneous evolutions of pore structure and particle contacts, and neglected the drainage processes of bulk water and meniscus water when subjected to any external hydro-mechanical loading condition. This paper proposes a state-dependent bimodal SWRC model considering pore structure evolution and pore-scale water drainage. In this model, an elastoplastic relationship is introduced to describe the variations of void ratio with net mean stress and suction, whilst the corresponding changes in the pore structure are modelled by the shift and scaling of the pore-size distribution and the volumetric proportion between the macro- and micro-pore systems. By relating stress-induced changes in void ratio and coordination number to the mean pore radius and total meniscus water volume, respectively, the soil water content at different stages of water drainage can be determined. The model is validated against existing and new data, and can capture the effects of void ratio, isotropic stress, and K0 stress for unimodal and bimodal soils.

Decreasing Incidence of Partial Meniscectomy, and Increasing Incidence of Meniscus Preservation Surgery from 2010-2020 in the United States

The aim of the present study was to characterize the incidence of meniscus surgery from 2010 to 2020 in the United States, using the metrics of age, sex, type of meniscus surgery, and Charlson Comorbidity Index (CCI). A retrospective analysis was performed using the PearlDiver national insurance claims database from 2010-2020. Meniscus surgeries were identified using Current Procedural Terminology codes. Patients were stratified by procedure type, age, biological sex, and Charlson Comorbidity Index (CCI) scores. Compound annual growth rate (CAGR) analysis and analysis of variance (ANOVA) were performed to analyze the trends and demographic variables between cohorts. Of 2,053,884 meniscus surgeries, 94.7% were meniscectomies, 0.3% were open repairs, 4.9% were arthroscopic repairs, and 0.1% were meniscal transplantations. CAGR analysis displayed a 4.0% decrease per year in total meniscus surgery. For individual procedure types, the largest decrease was in meniscectomy, and the largest increase was in open repair. Patients undergoing meniscal transplantation were youngest, with the lowest CCI. Meniscectomy patients were oldest, and open repair patients had the highest average CCI. Most procedures were performed on female patients (52.4%), and patients in the 50-59-year age group (30.4%). There was a sustained decrease in the incidence of total meniscus surgeries from 2010-2020. Meniscectomy was the procedure with the highest incidence, however, it showed the most significant decline in usage over the study period. Conversely, meniscal repair and transplantation procedures increased during the study period.

Total meniscus replacement with a 3D printing of network hydrogel composite scaffold in a rabbit model.

The aim of this study was to evaluate the role of a novel total meniscal implant in promoting meniscal regeneration and protecting articular cartilage in a rabbit model for 3 and 6 months. Thirty-six New Zealand rabbits were selected and divided into poly(ɛ-caprolactone) (PG-Pg) scaffold group, meniscectomy group and sham group. In this study, it was investigated whether PG-Pg scaffold can prevent articular cartilage degeneration and promote tissue degeneration, and its mechanical properties at 3 and 6 months after surgery were also explored. The degree of articular cartilage degeneration was significantly lower in the PG-Pg scaffold group than in the meniscectomy group. The number of chondrocytes increased in the PG-Pg scaffold at 3 and 6 months, while a gradual increase in the mechanical properties of the PG-Pg stent was observed from 6 months. The PG-Pg scaffold slows down the degeneration of articular cartilage, promotes tissue regeneration and improves biomechanical properties after meniscectomy. This novel meniscus scaffold holds promise for enhancing surgical strategies and delivering superior long-term results for individuals with severe meniscus tears. NA.

A comparative analysis of outcomes of surgical treatment of meniscus injuries in the knee joint in children after meniscectomy and meniscus suture repair

Introduction. The most common modalities of surgical treatment of meniscus injuries in children are meniscectomy and meniscal suture repair. However, indications and contraindications for both approaches in the pediatric practice is one of the most discussed problems. To more precisely define indications and contraindications for resection and meniscus suture repair will optimize management of meniscus injuries in children, thus improving outcomes and preventing early osteoarthritis of the knee joint.Purpose. To analyze outcomes after meniscectomy and meniscus suture repair in children after meniscus injuries.Material and methods. From 2015 till 2020, 120 children were treated in the department of traumatology and orthopedics (Morozovskaya Children's Clinical Hospital) for meniscus injuries. 88 patients (73.3%) from Group 1 had arthroscopic meniscus suture repair. 32 children (26.7%) from the comparison group had meniscectomy. All removed menisci were subjected to histological examination. Outcomes were assessed in 6 and 12 months after the surgery: clinical examination, MRI, radiography, and questionnaires with KOOS-Child and Pedi-IKDC scales.Results. In 6 months after the surgery, the following complaints were registered: after total meniscectomy pain was in 100% of patients; after partial resection of the meniscus pain was in 3.1% of patients. The basic complaint after meniscus suture repair was flexion restriction (10.2%). In 12 months after surgery, complaints were registered in 7 children after total meniscus resection (100% of all total meniscectomies), in 15 children after partial meniscus resection (60% of all partial meniscectomies), and in 14 children after meniscus suture repair (19.4% of all meniscus suture repairs). The assessment of clinical findings before and after meniscus suture repair in 6 and 12 months after the surgery has shown a statistically significant decrease in pain (p0.001), in swelling of the knee joint (p0.001) and relief of flexion restriction (p0.021), if to compare with partial meniscectomy.Conclusion. Unsatisfactory outcomes after total meniscectomy urge to exclude this type of intervention in the pediatric practice. Partial meniscectomy should be performed only if it is a case of multiple and multiplanar, multidirectional complex injury when meniscus repair is technically impossible. Marked cicatricial changes in the meniscus tissue which deform it and do not allow to make an anatomical reconstruction of the joint is also an indication for partial resection. If there are no marked degenerative changes and meniscus suture repair is technically possible, the damaged meniscus should be restored, regardless of the time of its injury and rupture location.

Research on Influencing Factors of Clinical Efficacy of Meniscus Resection Based on Logistic Regression Analysis.

In order to solve the factors affecting the clinical efficacy of meniscus resection, a method based on logistic regression analysis is proposed. From May 2019 to May 2020, 60 patients with discoid meniscus who underwent arthroscopic surgery in the Joint Department of the Second Hospital of a certain city were selected as the research objects; the surgical methods are divided into partial meniscus excision and plasty and total meniscus resection. The Lysholm function score was used to evaluate the clinical efficacy of arthroscopic surgery for discoid meniscus injuries before and 3, 6, and 12 months after surgery and postoperative application of Ikeuchi score and Tegner exercise ability score to assess age, gender, body mass index (BMI), duration of symptoms, and the influence of meniscus injury types and surgical methods on the efficacy of arthroscopic surgery for discoid meniscus injuries. Experimental results show that Ikeuchi's assessment of the excellent and good rate of arthroscopic knee joints was significantly higher than that of the control group, the incidence of postoperative pain was significantly lower than that of the control group, and the difference was statistically significant (P < 0.05). Postoperative pain and premature weight-bearing of discoid meniscus injury of knee joint, factors such as noncold compress after operation, articular cartilage damage, age, and time from onset to operation are closely related; the difference was statistically significant (P < 0.05). Postoperative evaluation according to Ikeuchi score: excellent in 38 cases, good in 14 cases, 8 cases were poor, and the excellent and good rate was 86.7%. The patient's age, type of meniscus tear, and duration of symptoms have a certain impact on the postoperative clinical efficacy of discoid meniscus injury; BMI and surgical methods have no significant impact. Logistic regression analysis results show that postoperative pain and premature weight-bearing of discoid meniscus injury of the knee joint, no cold compress after operation, accompanied by articular cartilage damage, age, and factors such as onset to operation time are closely related; the difference was statistically significant (P < 0.05). It proves that arthroscopic surgery for discoid meniscus injury has the advantages of less damage and faster recovery, it is the first choice for the treatment of discoid meniscus injury, and the postoperative effect is significant in young patients and those with short duration of symptoms; mixed tears have a greater impact on the postoperative recovery of patients with discoid meniscus injury; therefore, patients with discoid meniscus injury should undergo surgery as soon as possible and perform active rehabilitation exercises after the operation.

Strength of interference screw fixation of meniscus prosthesis matches native meniscus attachments

PurposeMeniscal surgery is one of the most common orthopaedic surgical interventions. Total meniscus replacements have been proposed as a solution for patients with irreparable meniscal injuries. Reliable fixation is crucial for the success and functionality of such implants. The aim of this study was to characterise an interference screw fixation system developed for a novel fibre-matrix-reinforced synthetic total meniscus replacement in an ovine cadaveric model.MethodsTextile straps were tested in tension to failure (n = 15) and in cyclic tension (70–220 N) for 1000 cycles (n = 5). The textile strap-interference screw fixation system was tested in 4.5 mm-diameter single anterior and double posterior tunnels in North of England Mule ovine tibias aged > 2 years using titanium alloy (Ti6Al4Va) and polyether-ether-ketone (PEEK) screws (n ≥ 5). Straps were preconditioned, dynamically loaded for 1000 cycles in tension (70–220 N), the fixation slippage under cyclic loading was measured, and then pulled to failure.ResultsStrap stiffness was at least 12 times that recorded for human meniscal roots. Strap creep strain at the maximum load (220 N) was 0.005 following 1000 cycles. For all tunnels, pull-out failure resulted from textile strap slippage or bone fracture rather than strap rupture, which demonstrated that the textile strap was comparatively stronger than the interference screw fixation system. Pull-out load (anterior 544 ± 119 N; posterior 889 ± 157 N) was comparable to human meniscal root strength. Fixation slippage was within the acceptable range for anterior cruciate ligament graft reconstruction (anterior 1.9 ± 0.7 mm; posterior 1.9 ± 0.5 mm).ConclusionThese findings show that the textile attachment-interference screw fixation system provides reliable fixation for a novel ovine meniscus implant, supporting progression to in vivo testing. This research provides a baseline for future development of novel human meniscus replacements, in relation to attachment design and fixation methods. The data suggest that surgical techniques familiar from ligament reconstruction may be used for the fixation of clinical meniscal prostheses.

Meniscus position and size in knees with versus without structural knee osteoarthritis progression: data from the osteoarthritis initiative

ObjectiveTo explore whether and which quantitative 3D measures of medial and/or lateral meniscus position and size are associated with subsequent medial femorotibial structural progression of knee osteoarthritis and to determine the correlation between central slice and total meniscus measures.Materials and MethodsKnees with radiographic osteoarthritis from Osteoarthritis Initiative participants with longitudinal medial MRI-based cartilage thickness and radiographic joint space width (JSW) loss over 12 months were selected. These 37 structural progressor knees (64.7 ± 8.0y, 30.2 ± 4.6 kg/m2, 35% men) were matched 1:1 to 37 non-progressor knees (64.6 ± 9.8y, 30.2 ± 4.4 kg/m2, 35% men) without cartilage thickness or JSW loss. Quantitative measures of meniscus position and size were computed from manual segmentations of coronal baseline MRIs. Cohen’s D was used as measure of effect size.ResultsMaximum extrusion distance of the total medial meniscus and mean extrusion in the central 5 and in the central slice were greater for progressor than non-progressor knees (Cohen’s D 0.58–0.66). No significant differences were observed for medial tibial coverage or mean extrusion (entire meniscus). Among medial meniscus morphology measures, only mean height differed between progressor vs non-progressor knees (Cohen’s D 0.40). Among lateral meniscus measures, height and volume were greater in progressor vs. non-progressor knees (Cohen’s D 0.46–0.83). Mean extrusion measures were highly correlated between the entire meniscus and the central (r = 0.88) or the central 5 (r = 0.93) slices.Conclusions3D maximum and central medial meniscus extrusion may serve as predictors for subsequent structural progression. Central meniscus extrusion measures could substitute 3D extrusion measurement across the entire meniscus.

Selection of Highly Proliferative and Multipotent Meniscus Progenitors through Differential Adhesion to Fibronectin: A Novel Approach in Meniscus Tissue Engineering

Meniscus injuries can be highly debilitating and lead to knee osteoarthritis. Progenitor cells from the meniscus could be a superior cell type for meniscus repair and tissue-engineering. The purpose of this study is to characterize meniscus progenitor cells isolated by differential adhesion to fibronectin (FN-prog). Human osteoarthritic menisci were digested, and FN-prog were selected by differential adhesion to fibronectin. Multilineage differentiation, population doubling time, colony formation, and MSC surface markers were assessed in the FN-prog and the total meniscus population (Men). Colony formation was compared between outer and inner zone meniscus digest. Chondrogenic pellet cultures were performed for redifferentiation. FN-prog demonstrated multipotency. The outer zone FN-prog formed more colonies than the inner zone FN-prog. FN-prog displayed more colony formation and a higher proliferation rate than Men. FN-prog redifferentiated in pellet culture and mostly adhered to the MSC surface marker profile, except for HLA-DR receptor expression. This is the first study that demonstrates differential adhesion to fibronectin for the isolation of a progenitor-like population from the meniscus. The high proliferation rates and ability to form meniscus extracellular matrix upon redifferentiation, together with the broad availability of osteoarthritis meniscus tissue, make FN-prog a promising cell type for clinical translation in meniscus tissue-engineering.

Total Meniscus Reconstruction Using a Polymeric Hybrid-Scaffold: Combined with 3D-Printed Biomimetic Framework and Micro-Particle.

The meniscus has poor intrinsic regenerative capability, and its injury inevitably leads to articular cartilage degeneration. Although there are commercialized off-the-shelf alternatives to achieve total meniscus regeneration, each has its own shortcomings such as individualized size matching issues and inappropriate mechanical properties. We manufactured a polycaprolactone-based patient-specific designed framework via a Computed Tomography scan images and 3D-printing technique. Then, we completed the hybrid-scaffold by combining the 3D-printed framework and mixture micro-size composite which consists of polycaprolactone and sodium chloride to create a cell-friendly microenvironment. Based on this hybrid-scaffold with an autograft cell source (fibrochondrocyte), we assessed mechanical and histological results using the rabbit total meniscectomy model. At postoperative 12-week, hybrid-scaffold achieved neo-meniscus tissue formation, and its shape was maintained without rupture or break away from the knee joint. Histological and immunohistochemical analysis results showed obvious ingrowth of the fibroblast-like cells and chondrocyte cells as well as mature lacunae that were embedded in the extracellular matrix. Hybrid-scaffolding resulted in superior shape matching as compared to original meniscus tissue. Histological analysis showed evidence of extensive neo-meniscus cell ingrowth. Additionally, the hybrid-scaffold did not induce osteoarthritis on the femoral condyle surface. The 3D-printed hybrid-scaffold may provide a promising approach that can be applied to those who received total meniscal resection, using patient-specific design and autogenous cell source.

Comprehensive hydrolytic degradation study of a new poly(ester-amide) used for total meniscus replacement

Total meniscus replacement scaffolds composed of a collagen-hyaluronan sponge reinforced with poly(desaminotyrosyl-tyrosine dodecyl dodecanedioate) (poly(DTD DD)) fibers support formation of functional neo-meniscus tissue in a sheep model. Poly(DTD DD) is a new polymer that was specifically designed to meet the required mechanical properties while exhibiting a high degree of biocompatibility. Extensive in vivo studies confirmed the overall success of this device. To ensure adequate healing, poly(DTD DD) was intentionally designed to be a very slowly degrading polymer: at two years post-implantation, some residual poly(DTD DD) fibers remained at the implant site. In order to understand the mechanism and the kinetics of poly(DTD DD) degradation, a comprehensive degradation study was carried out under physiological and accelerated conditions. Using accelerated degradation methods (elevated temperature, organic cosolvent, and enzyme), the degradation pathway, end-stage degradation products, and rates of degradation were determined. The degradation of desaminotyrosyl-tyrosine dodecyl ester (DTD) monomer was studied using a variety of esterases and proteases for their activity and stability. Porcine pancreas lipase (PP-L) was found to be the most effective enzyme for DTD degradation. Of all the conditions tested, the temperature-accelerated method (60°C) showed the fastest degradation rate of poly(DTD DD) fibers; after about 40 weeks, poly(DTD DD) retained less than 6% of its initial number average molecular weight (Mn). In contrast, 58%, 43%, and 53% of the original number average molecular weight (Mn) was retained after 40 weeks under solvent-accelerated (methanol:water mixture, 37°C), enzyme-accelerated (PP-L, 37°C), and physiological conditions (37°C), respectively. Resorbable degradation products were first observed after the polymer fibers degraded to about 22% of their initial Mn, corresponding to a residual Mn of 19 kDa. Elucidation of the complete degradation mechanism has provided important information necessary for the use of this innovative polymer for meniscus replacement and in other medical devices.

Cell-free 3D wet-electrospun PCL/silk fibroin/Sr2+ scaffold promotes successful total meniscus regeneration in a rabbit model

Considering the intrinsic poor self-healing capacity of meniscus, tissue engineering has become a new direction for the treatment of meniscus lesions. However, disturbed by mechanical stability and biocompatibility, most meniscus implants fail to relieve symptoms and prevent the development of osteoarthritis. The goal of this study was to develop a potential meniscal substitute for clinical application. Here, silk fibroin with good mechanical performance and biocompatibility, and strontium ion acting as bioactive factor, were incorporated with Ɛ-Polycaprolactone to fabricate a meniscus scaffold (SP-Sr). By the wet-electrospun method, the 3D SP-Sr provided suitable pore size (100–200 μm) and enough mechanical support (61.6 ± 2.9 MPa for tensile modulus and 0.11 ± 0.03 MPa for compressive modulus). Moreover, after addition of Sr2+, the SP-Sr seeded by rabbit adipose tissue-derived stromal cells (rADSCs) showed the highest secretion with 2.61- and 2.98-fold increase in collagen and aggrecan, respectively, compared with SF/PCL group. And the extracellular matrix related genes expression in SP-Sr also showed upregulation results. Particularly, the expression of the collagen II gene, which played a crucial role in the formation of meniscal inner avascular region, showed a 9-fold increase in SP-Sr compared with pure PCL group. Furthermore, the MRI results of SP-Sr implanted in rabbits with total meniscectomy for 6 months demonstrated effective prevention of meniscus extrusion and relieving joint space narrowing compared with meniscectomy group. And the effects of cartilage protection and delaying osteoarthritis development were confirmed by Pathological examination. Especially, after 6-month implantation, the neo-menisci showed similar structural constituent and mechanical performance. Statement of significanceMeniscus regeneration faces great challenge due to the meniscus having limited healing potential owing to its anisotropic structure, its hypocellularity and hypovascularity. The present tissue engineering solutions have failed to maintain the biological function for meniscus reconstruction in vivo because of fragile and poor biocompatible materials, leading to long-term joint degeneration. The goal of this study was to develop a meniscal substitute potential for clinical application. Here, silk fibroin and strontium were incorporated with Ɛ-Polycaprolactone by wet-electrospinning method to fabricate a meniscus scaffold (SP-Sr). The 6-month implantation results revealed that SP-Sr scaffold was effective in preventing meniscus extrusion, cartilage protection and delaying osteoarthritis development, and the regenerated menisci showed similar structural constituent and mechanical performance.

THE EFFECTS OF EXERCISE ON THE REHABILITATION OF KNEE LIGAMENT INJURIES IN ATHLETES

The purpose of the present study was to examine the effects of exercise on the rehabilitation of knee ligament injuries in athletes and to identify what the injured athletes consider as the most effective treatment concerning their rehabilitation, through the administration of a reported condition inquiry. Two hundred ninety six healthy subjects, 22,59 + 6,31 years old, participated in the research. All the subjects were active or former athletes, competed or had competed in athletic clubs throughout Greece, in various team sports or individual sports and competing categories and had suffered a knee ligament injury in their career as athletes. The effects of exercise on the rehabilitation of knee ligament injuries were measured through a scale of measurements. For data analysis was used the descriptive analysis of the SPSS version 20 for Windows . Data processing showed that the highest percentage of the knee injuries (43,80%) concerns anterior cruciate ligament (ACL) rupture, 34,40% partial or total meniscus rupture, 15,60% ligament injuries and 6,20% medial collateral ligament (MCL) or lateral collateral ligament (LCL) rupture. More than half of the knee injuries (53,10%), namely ruptures of ACL (76,50%), the partial-total rupture of meniscus (17,60%), and the patella dislocations and partial ruptures of MCL and LCL (5,90%), were treated surgically, combined with abstaining from training and matches, medication, bandage usage, immobilization with plaster-brace, medical examinations, physiotherapies, and special therapeutic exercise. The rest of the cases of the knee injuries (46,90%), namely all the cases of ligament over-voltages, ¾ of the meniscus ruptures, half of the patella dislocations and partial ruptures of MCL and LCL, as well as 1,25% of ACL rupture, were treated conservatively, with different combinations of physiotherapies, special therapeutic exercises, abstention from training and games, medication, bandage usage, immobilization with plaster-brace, further medical examinations. In addition, almost all the injured athletes (except a 6,20%) did a combination of exercise modes for the rehabilitation of their knee ligament injury. More specifically, 18,80% did exercises with straps, resistance bands, weightbearing and isokinetic machine. In addition, 15,60% did exercises with straps, resistance bands, weightbearing, exercises in the water and isokinetic machine and the same percentage (15,60%) did exercises with straps, resistance bands, weightbearing and exercises in the water. 12,50% did exercises with resistance bands and weightbearing, 9,40% did exercises with resistance bands and in smaller percentages the athletes did exercises in the water and gaiting (6,20%), exercises with straps, resistance bands and weightbearing (6,20%), exercises with straps and resistance bands (3,10%), exercises with isokinetic machine and exercises in the water (3,10%), as well as exercises with resistance bands, exercises in the water and in the isokinetic machine (3,10%). In addition, 93,80% of the athletes stated that their knee ligament injury is completely or partially restored. Concerning the athletes’ opinions, 43,80% consider that the most effective treatment for the rehabilitation of their knee ligament injury was strengthening with weightbearing and resistance bands. Likewise, 35,30% of the athletes who underwent surgery consider strengthening mainly by weightbearing and resistance bands as the most effective treatment for the rehabilitation of their injury. In conclusion, according to the opinions of the athletes, who treated their knee ligament injury both non-operatively and operatively, the most effective treatment for the rehabilitation of the knee ligament injury was exercise in the mode of weightbearing and resistance bands. Thus, it could be said that exercise brings about significant positive effects on the rehabilitation of the knee ligament injury. Consequently, exercise should be an integral part of the knee ligament injury rehabilitation and prevention. Article visualizations:

THE EFFECTS OF EXERCISE ON THE REHABILITATION OF KNEE LIGAMENT INJURIES IN ATHLETES

The purpose of the present study was to examine the effects of exercise on the rehabilitation of knee ligament injuries in athletes and to identify what the injured athletes consider as the most effective treatment concerning their rehabilitation, through the administration of a reported condition inquiry. Two hundred ninety six healthy subjects, 22,59 + 6,31 years old, participated in the research. All the subjects were active or former athletes, competed or had competed in athletic clubs throughout Greece, in various team sports or individual sports and competing categories and had suffered a knee ligament injury in their career as athletes. The effects of exercise on the rehabilitation of knee ligament injuries were measured through a scale of measurements. For data analysis was used the descriptive analysis of the SPSS version 20 for Windows . Data processing showed that the highest percentage of the knee injuries (43,80%) concerns anterior cruciate ligament (ACL) rupture, 34,40% partial or total meniscus rupture, 15,60% ligament injuries and 6,20% medial collateral ligament (MCL) or lateral collateral ligament (LCL) rupture. More than half of the knee injuries (53,10%), namely ruptures of ACL (76,50%), the partial-total rupture of meniscus (17,60%), and the patella dislocations and partial ruptures of MCL and LCL (5,90%), were treated surgically, combined with abstaining from training and matches, medication, bandage usage, immobilization with plaster-brace, medical examinations, physiotherapies, and special therapeutic exercise. The rest of the cases of the knee injuries (46,90%), namely all the cases of ligament over-voltages, ¾ of the meniscus ruptures, half of the patella dislocations and partial ruptures of MCL and LCL, as well as 1,25% of ACL rupture, were treated conservatively, with different combinations of physiotherapies, special therapeutic exercises, abstention from training and games, medication, bandage usage, immobilization with plaster-brace, further medical examinations. In addition, almost all the injured athletes (except a 6,20%) did a combination of exercise modes for the rehabilitation of their knee ligament injury. More specifically, 18,80% did exercises with straps, resistance bands, weightbearing and isokinetic machine. In addition, 15,60% did exercises with straps, resistance bands, weightbearing, exercises in the water and isokinetic machine and the same percentage (15,60%) did exercises with straps, resistance bands, weightbearing and exercises in the water. 12,50% did exercises with resistance bands and weightbearing, 9,40% did exercises with resistance bands and in smaller percentages the athletes did exercises in the water and gaiting (6,20%), exercises with straps, resistance bands and weightbearing (6,20%), exercises with straps and resistance bands (3,10%), exercises with isokinetic machine and exercises in the water (3,10%), as well as exercises with resistance bands, exercises in the water and in the isokinetic machine (3,10%). In addition, 93,80% of the athletes stated that their knee ligament injury is completely or partially restored. Concerning the athletes’ opinions, 43,80% consider that the most effective treatment for the rehabilitation of their knee ligament injury was strengthening with weightbearing and resistance bands. Likewise, 35,30% of the athletes who underwent surgery consider strengthening mainly by weightbearing and resistance bands as the most effective treatment for the rehabilitation of their injury. In conclusion, according to the opinions of the athletes, who treated their knee ligament injury both non-operatively and operatively, the most effective treatment for the rehabilitation of the knee ligament injury was exercise in the mode of weightbearing and resistance bands. Thus, it could be said that exercise brings about significant positive effects on the rehabilitation of the knee ligament injury. Consequently, exercise should be an integral part of the knee ligament injury rehabilitation and prevention. Article visualizations:

Meniscus position and size in knees with versus without structural knee osteoarthritis progression - data from the osteoarthritis initiative

To explore whether and which quantitative 3D measures of medial and/or lateral meniscus position and size are associated with subsequent medial femorotibial structural progression of knee osteoarthritis and to determine the correlation between central slice and total meniscus measures. Knees with radiographic osteoarthritis from Osteoarthritis Initiative participants with longitudinal medial MRI-based cartilage thickness and radiographic joint space width (JSW) loss over 12 months were selected. These 37 structural progressor knees (64.7 ± 8.0y, 30.2 ± 4.6 kg/m2, 35% men) were matched 1:1 to 37 non-progressor knees (64.6 ± 9.8y, 30.2 ± 4.4 kg/m2, 35% men) without cartilage thickness or JSW loss. Quantitative measures of meniscus position and size were computed from manual segmentations of coronal baseline MRIs. Cohen’s D was used as measure of effect size. Maximum extrusion distance of the total medial meniscus and mean extrusion in the central 5 and in the central slice were greater for progressor than non-progressor knees (Cohen’s D 0.58–0.66). No significant differences were observed for medial tibial coverage or mean extrusion (entire meniscus). Among medial meniscus morphology measures, only mean height differed between progressor vs non-progressor knees (Cohen’s D 0.40). Among lateral meniscus measures, height and volume were greater in progressor vs. non-progressor knees (Cohen’s D 0.46–0.83). Mean extrusion measures were highly correlated between the entire meniscus and the central (r = 0.88) or the central 5 (r = 0.93) slices. 3D maximum and central medial meniscus extrusion may serve as predictors for subsequent structural progression. Central meniscus extrusion measures could substitute 3D extrusion measurement across the entire meniscus.

A 3D printed PCL/hydrogel construct with zone-specific biochemical composition mimicking that of the meniscus

Engineering the meniscus is challenging due to its bizonal structure; the tissue is cartilaginous at the inner portion and fibrous at the outer portion. Here, we constructed an artificial meniscus mimicking the biochemical organization of the native tissue by 3D printing a meniscus shaped PCL scaffold and then impregnating it with agarose (Ag) and gelatin methacrylate (GelMA) hydrogels in the inner and outer regions, respectively. After incubating the constructs loaded with porcine fibrochondrocytes for 8 weeks, we demonstrated that presence of Ag enhanced glycosaminoglycan (GAG) production by about 4 fold (p < 0.001), while GelMA enhanced collagen production by about 50 fold (p < 0.001). In order to mimic the physiological loading environment, meniscus shaped PCL/hydrogel constructs were dynamically stimulated at strain levels gradually increasing from the outer region (2% of initial thickness) towards the inner region (10%). Incorporation of hydrogels protected the cells from the mechanical damage caused by dynamic stress. Dynamic stimulation resulted in increased ratio of collagen type II (COL 2) in the Ag-impregnated inner region (from 50% to 60% of total collagen), and increased ratio of collagen type I (COL 1) in the GelMA-impregnated outer region (from 60% to 70%). We were able to engineer a meniscus, which is cartilage-like at the inner portion and fibrocartilage-like at the outer portion. Our construct has a potential for use as a substitute for total meniscus replacement.

Tissue-Engineered Total Meniscus Replacement With a Fiber-Reinforced Scaffold in a 2-Year Ovine Model

Background: Meniscus injuries and associated meniscectomies cause patients long-term pain and discomfort and can lead to joint deterioration. Purpose: To evaluate a collagen-hyaluronan sponge reinforced with synthetic resorbable polymer fiber for total meniscus reconstruction in a long-term ovine model. Study Design: Controlled laboratory study. Methods: Eleven skeletally mature sheep were implanted with the total meniscus scaffold. At 2 years, explants were evaluated biologically (radial/circumferential histology, immunofluorescence) and mechanically (compression, tension), and articular surfaces were examined for damage. Results: The fiber-reinforced scaffold induced formation of functional neomeniscus tissue that was intact in 8 of 11 animals. The implant was remodeled into organized circumferentially aligned collagen bundles to resist meniscus hoop stresses. Moreover, type II collagen and proteoglycan deposition near the inner margin suggested a direct response to compressive stresses and confirmed fibrocartilage formation. Cartilage damage was observed, but end-stage (severe) joint deterioration associated with meniscectomy was avoided, even with limitations regarding the ovine surgical procedure and postoperative care. Conclusion: A fiber-reinforced total meniscus replacement device induces formation of functional neomeniscus tissue that has the potential to prevent catastrophic joint deterioration associated with meniscectomy. Clinical Relevance: An off-the-shelf meniscus device that can be remodeled into functional tissue and thus prevent or delay the onset of osteoarthritis could address a widespread clinical need after meniscus injury.

The Radiated Deep-frozen Xenogenic Meniscal Tissue Regenerated the Total Meniscus with Chondroprotection

Meniscal allograft transplantation yields good and excellent results but is limited by donor availability. The purpose of the study was to evaluate the effectiveness of radiated deep-frozen xenogenic meniscal tissue (RDF-X) as an alternative graft choice in meniscal transplantation. The xenogenic meniscal tissues were harvested from the inner 1/3 part of the porcine meniscus and then irradiated and deeply frozen. The medial menisci of rabbits were replaced by the RDF-X. Meniscal allograft transplantation, meniscectomy and sham operation served as controls. Only a particular kind of rabbit-anti-pig antibody (molecular ranging 60–80 kD) was detected in the blood serum at week 2. The menisci of the group RDF-X grossly resembled the native tissue and the allograft meniscus with fibrocartilage regeneration at postoperative 1 year. Cell incorporation and the extracellular matrix were mostly observed at the surface and the inner 1/3 part of the newly regenerated RDF-X, which was different from the allograft. The biomechanical properties of the group RDF-X were also approximate to those of the native meniscus except for the compressive creep. In addition, chondroprotection was achieved after the RDF-X transplantation although the joint degeneration was not completely prevented. To conclude, the RDF-X could be a promising alternative for meniscal transplantation with similar tissue regeneration capacity to allograft transplantation and superior chondroprotection. The potential minor immunological rejection should be further studied before its clinical application.

Interference Screw Versus Suture Endobutton Fixation of a Fiber-Reinforced Meniscus Replacement Device in a Human Cadaveric Knee Model

Background: Meniscal lesions represent one of the most common intra-articular knee injuries. Meniscus replacement devices are needed to restore load distribution and knee stability after meniscectomy. Fixation of these devices is crucial to the generation of hoop stresses and the distribution of loads in the joint. Purpose: To evaluate 2 different fixation techniques (suture endobutton and interference screw) for implantation of a novel meniscus device. Study Design: Controlled laboratory study. Methods: In 7 human cadaveric knees (aged 17-61 years), 1 anterior and 2 potential posterior tunnel locations were investigated, and both fixation techniques were tested in each tunnel. The native meniscus roots, devices fixed with a suture endobutton, and devices fixed with an interference screw were gripped with cryoclamps, and tibias were drilled and loaded into a custom jig. Samples were preloaded, preconditioned, loaded for 500 cycles (50-150 N), and tested in tension until failure. Results: For all 3 tunnels, suture fixation resulted in greater elongation (54.1%-150.7% greater; P < .05) during cyclic loading than interference screw fixation, which approximated the native roots. Both fixation techniques displayed ultimate tensile loads in the same range as native roots. However, stiffness of the suture fixation groups (36.5-41.6 N/mm) was only 28% to 37% of that of the interference screw fixation groups (98.7-131.6 N/mm), which had values approaching those of the native roots (anterior: 175.4 ± 24.2 N/mm; posterior: 157.6 ± 22.9 N/mm). Conclusion: Interference screw fixation was found to be superior to suture fixation with regard to elongation and stiffness, a finding that should be considered in the design and implantation of novel meniscus replacement devices. Clinical Relevance: With the emergence of various devices for total meniscus replacement, the establishment of fixation strategies is crucial for the generation of tensile hoop stresses and the efficacy of these approaches.

Human Knee Meniscus Regeneration Strategies: a Review on Recent Advances.

Lack of vascularity in the human knee meniscus often leads to surgical removal (total or partial meniscectomy) in the case of severe meniscal damage. However, complete recovery is in question after such removal as the meniscus plays an important role in knee stability. Thus, meniscus tissue regeneration strategies are of intense research interest in recent years. The structural complexity and inhomogeneity of the meniscus have been addressed with processing technologies for precisely controlled three dimensional (3D) complex porous scaffold architectures, the use of biomolecules and nanomaterials. The regeneration and replacement of the total meniscus have been studied by the orthopedic and scientific communities via successful pre-clinical trials towards mimicking the biomechanical properties of the human knee meniscus. Researchers have attempted different regeneration strategies which contribute to in vitro regeneration and are capable of repairing meniscal tears to some extent. This review discusses the present state of the art of these meniscus tissue engineering aspects.