Proteoglycans in articular cartilage and their contribution to chondral injury and repair mechanisms

Proteoglycans are vital components of the extracellular matrix in articular cartilage, providing biomechanical properties crucial for its proper functioning. They are key players in chondral diseases, specifically in the degradation of the extracellular matrix. Evaluating proteoglycan molecules can serve as a biomarker for joint degradation in osteoarthritis patients, as well as assessing the quality of repaired tissue following different treatment strategies for chondral injuries. Despite ongoing research, understanding osteoarthritis and cartilage repair remains unclear, making the identification of key molecules essential for early diagnosis and effective treatment. This review offers an overview of proteoglycans as primary molecules in articular cartilage. It describes the various types of proteoglycans present in both healthy and damaged cartilage, highlighting their roles. Additionally, the review emphasizes the importance of assessing proteoglycans to evaluate the quality of repaired articular tissue. It concludes by providing a visual and narrative description of aggrecan distribution and presence in healthy cartilage. Proteoglycans, such as aggrecan, biglycan, decorin, perlecan, and versican, significantly contribute to maintaining the health of articular cartilage and the cartilage repair process. Therefore, studying these proteoglycans is vital for early diagnosis, evaluating the quality of repaired cartilage, and assessing treatment effectiveness

Resultados de la técnica de Zarins en la reconstrucción del ligamento cruzado anterior

Se presenta una serie de 96 pacientes con lesión crónica del ligamento cruzado anterior de la rodilla que fueron intervenidos mediante un procedimiento combinado intra y extraarticular que utiliza como método de reconstrucción el tendón del semitendinoso y una tira de fascia lata. Ochenta y cinco pacientes pudieron ser revisados a una media de 119 meses de la intervención (rango 110-130). El test de Lachman instrumentado con Genucom fue inferior a 5mm en el 88% de los casos y el pívot-shift fue negativo en el 91%. Se observaron cambios radiológicos en 52% de las rodillas. De acuerdo con la escala de Zarins, 88% de pacientes fueron calificados de excelentes o buenos. En la escala de Lysholm, la puntuación media fue de 93 puntos. Los resultados demuestran que esta técnica puede restaurar la estabilidad de la rodilla con déficit del LCA a largo plazo.Ninety-six patients who had chronic lesions of the anterior cruciata were treated using a combined method of intraarticular and extraarticular transfer of the semitendinous tendon and a strip of fascia lata (Zarins technique). Eighty-five patients were studied at 119 (110 to 130) months after surgery. In 88 percent of the patients, instrumented measurement of anteroposterior laxity at 30 degrees knee flexion was zero to five milimeters. The pivot shift test was negative in 91 percent of them. Radiological changes were observed in 52 percent of the patients. According to the Zarins scale, 88 percent of the patients were rated as excellent or good. Lysholm evaluation showed an average of 93 points. This study demonstrates that this method can restore long term stability to a knee that has a torn anterior cruciate ligament

The Dual-Responsive Interaction of Particulated Hyaline Cartilage and Plasma Rich in Growth Factors (PRGF) in the Repair of Cartilage Defects: An In Vitro Study

The treatment of chondral and osteochondral defects is challenging. These types of lesions are painful and progress to osteoarthritis over time. Tissue engineering offers tools to address this unmet medical need. The use of an autologous cartilage construct consisting of hyaline cartilage chips embedded in plasma rich in growth factors (PRGF) has been proposed as a therapeutic alternative. The purpose of this study was to dig into the potential mechanisms behind the in vitro remodelling process that might explain the clinical success of this technique and facilitate its optimisation. Chondrocyte viability and cellular behaviour over eight weeks of in vitro culture, type II collagen synthesis, the dual delivery of growth factors by hyaline cartilage and PRGF matrix, and the ultrastructure of the construct and its remodelling were characterised. The main finding of this research is that the cartilage fragments embedded in the three-dimensional PRGF scaffold contain viable chondrocytes that are able to migrate into the fibrin network, proliferate and synthesise extracellular matrix after the second week of in vitro culture. The characterization of this three-dimensional matrix is key to unravelling the molecular kinetics responsible for its efficacy.This study received funding from the Basque Country Government, within the Hazitek program, and support program for collaborative research in strategic area, within the project named EndoCarTech (grant number ZL-2020/00937)

Assessment of the effect of intraarticular injection of autologous adipose-derived mesenchymal stem cells in osteoarthritic dogs using a double blinded force platform analysis

BACKGROUND: Regenerative medicine using Mesenchymal Stem Cells (MSC) alone or combined with Plasma Rich in Growth Factors (PRGF) is a rapidly growing area of clinical research and is currently also being used to treat osteoarthritis (OA). Force platform analysis has been consistently used to verify and quantify the efficacy of different therapeutic strategies for the treatment of OA in dogs including MSC associated to PRGF, but never with AD-MSC alone. The aim of this study was to use a force platform to measure the efficacy of intraarticular ADMSC administration for limb function improvement in dogs with severe OA. RESULTS: Ten lame dogs with severe hip OA and a control group of 5 sound dogs were used for this study. Results were statistically analyzed to detect a significant increase in peak vertical force (PVF) and vertical impulse (VI) in treated dogs. Mean values of PVF and VI were significantly improved within the first three months post-treatment in the OA group, increasing 9% and 2.5% body weight, respectively, at day 30. After this, the effect seems to decrease reaching initial values. CONCLUSION: Intraarticular ADMSC therapy objectively improved limb function in dogs with hip OA. The duration of maximal effect was less than 3 months

Roturas “irreparables” del manguito rotador: trucos y consejos para conseguir una reparación artroscópica

Las roturas irreparables del manguito rotador son lesiones graves que pueden conllevar consecuencias drásticas en la calidad de vida de los pacientes. Pese a que su reparación es compleja y la tasa de re-rotura es alta, el intento de reparación se justifica por la ausencia de alternativas poco agresivas o paliativas. Cuando no se consigue una reparación, la alternativa es la transferencia tendinosa, la reconstrucción capsular superior o incluso la prótesis invertida de hombro. Por tanto, en muchos casos de cirugía primaria, se debe intentar la reparación artroscópica con el fin de “salvar” el manguito rotador gravemente lesionado. El objetivo de este artículo es resumir algunas de las técnicas artroscópicas para conseguir una reparación de roturas “irreparables” del manguito rotador

Serum Collagen Type II Cleavage Epitope and Serum Hyaluronic Acid as Biomarkers for Treatment Monitoring of Dogs with Hip Osteoarthritis

The aim of this study was to evaluate the use of serum type II collagen cleavage epitope and serum hyaluronic acid as biomarkers for treatment monitoring in osteoarthritic dogs. For this purpose, a treatment model based on mesenchymal stem cells derived from adipose tissue combined with plasma rich in growth factors was used. This clinical study included 10 dogs with hip osteoarthritis. Both analytes were measured in serum at baseline, just before applying the treatment, and 1, 3, and 6 months after treatment. These results were compared with those obtained from force plate analysis using the same animals during the same study period. Levels of type II collagen cleavage epitope decreased and those of hyaluronic acid increased with clinical improvement objectively verified via force plate analysis, suggesting these two biomarkers could be effective as indicators of clinical development of joint disease in dogs. Introductio

Immunohistochemical analysis of knee chondral defect repair after autologous particulated cartilage and platelet-rich plasma treatment in sheep

This study performs an analysis that will enable the evaluation of the quality, durability, and structure of repaired cartilaginous extracellular matrix tissue using an autologous-based particulated autograft cartilage and platelet-rich plasma treatment (PACI + PRP). A single-blind controlled experiment was conducted on 28 sheep to evaluate the efficacy of the PACI + PRP treatment for cartilage defects. Full-thickness 8 mm diameter defects were created in the weight-bearing area of both knees. The right knees received PACI + PRP. The left knees were treated with Ringer’s lactate solution (RLS) or hyaluronic acid (HA) injections. Sheep were euthanized at 9- or 18-months post-surgery. An extensive immunohistochemical analysis was performed to assess collagen types (I, II, III, V, VI, IX, X, XI) and aggrecan positivity. A semiquantitative scoring system provided a detailed evaluation of immunostaining. Collagens and aggrecan scores in the PACI + PRP groups were similar to healthy cartilage. Significant differences were found in collagens associated with matrix maturity (II and V), degradation (IX), structure and mechanics (VI), and hypertrophy (X) between healthy cartilage and RLS- or HA-repaired cartilage. The PACI + PRP treatment advanced the repair cartilage process in chondral defects with mature hyaline cartilage and enhanced the structural and mechanical qualities with better consistent cartilage, less susceptible to degradation and without hypertrophic formation over tim

Development of a new methodology for articular cartilage’s mechanical evaluation

El Instituto de Biomecánica de Valencia (IBV) ha desarrollado y puesto en práctica una nueva metodología para la evaluación mecánica de cartílago articular. El protocolo diseñado ha permitido comparar las características mecánicas del cartílago articular sano con las del cartílago tratado con plasma rico en factores de crecimiento y con suero salino fisiológico.Instituto de Biomecánica de Valencia (IBV) developed and updated a new method for assessing the biomechanical properties of knee articular cartilage. The designed protocol has allowed to compare mechanical behaviour of healthy cartilage with articular cartilage treated by plasma rich in growth factors and physiological saline serum.Veterinari

Histological and biochemical evaluation of plasma rich in growth factors treatment for grade II muscle injuries in sheep.

The purpose of this study was to perform a histological and biochemical evaluation of the influence of plasma rich in growth factors (PRGF) on muscle regeneration process after a surgically induced grade II muscle laceration. A randomized, single blind, controlled experimental research was conducted including twenty-one adult healthy sheep, randomly divided in three groups (n = 7). A grade II surgical section was performed in the biceps femoris muscle of both hindlimbs. After two days (basal time), intralesional infiltration of autologous PRGF or Saline solution was randomly administered in both hindlimbs. Treatment was repeated once a week. Animal groups were euthanized at 1 (T1), 2 (T2) or 4 (T4) weeks. Histological assessment showed that PRGF intralesional injection induced a significant decrease of inflammatory cells density, significant higher centrally nucleated fibers percentage and significantly smaller fibrotic areas compared to Saline-treated muscles at T1, T2 and T4. Also, lower vascular density, with lower capillaries cross-sectional area, in PRGF group compared to Saline was observed. Biochemical analysis revealed a significant higher expression level of MYOD1, MYF5 and MYOG genes in PRGF groups at T1 compared to Saline treated muscles. At ultrastructural level, PRGF groups presented scarce edema and loss of connective tissue structure, as well as higher mitochondrial density adequately associated to the sarcomere unit in contrast to the Saline group. In conclusion, histological, biochemical, and ultrastructural results showed that PRGF treatment improved muscle regeneration process leading to more mature histological aspect in newly formed muscle tissue after a surgically induced grade II muscle injury