Femoral Condyle Articular Cartilage Research Articles

Пространственное распределение протеогликанов суставного хряща бедренных мыщелков и тибиального плато при экспериментальном остеоартрозе у крыс

Introduction. Very few works have studied the spatial distribution of proteoglycans of the articular cartilage of femoral condyles (FCs) and the tibial plateau (TP) in normal and experimental osteoarthritis (OA). The aim of the paper was to analyze the spatial distribution of lubricin and aggrecan in the articular cartilage of FCs and the TP in normal and experimental OA in rats. Materials and methods. We divided 15 male Wistar rats (weight 250–300 g) into three groups: intact, undergone sham surgery, and having experimental OA. Sham surgery was done with intra-articular injection of saline solution, and experimental OA was modeled by intra-articular injection of medical talc. We performed morphological and immunohistochemical studies using antibodies to Aggrecan and Lubricin to assess the spatial distribution of proteoglycans. Results. After 3 weeks in the group with OA, the thickness of the articular cartilage of FCs and the TP was 15% greater and 11% less, respectively, in comparison with that in the intact rats (p<0.05). In the intact group, the numerical density of chondrocytes of the superficial zone of the articular cartilage of the TP was 2.6 times higher compared to that of FCs; after 3 weeks, the group with OA showed the opposite trend. A similar pattern was in the middle and deep zones. Immunohistochemistry revealed the presence of intense staining on lubricin of isogenic groups of chondrocytes and extracellular matrix (ECM) of the middle zone of the articular cartilage of the TP in experimental OA. Conclusion. In experimental OA, we observed interstitial growth in the articular cartilage of FCs and signs of ECM destruction in superficial and middle zones of the articular cartilage of the TP. In experimental OA, the distribution of lubricin synthesis changes. For the middle zone chondrocytes, localized close to the surface zone, the color on lubricin is characteristic. Keywords: morphology, articular cartilage, aggrecan, lubricin, femoral condyles, tibial plateau, osteoarthritis, rat

Combination of a human articular cartilage-derived extracellular matrix scaffold and microfracture techniques for cartilage regeneration: A proof of concept in a sheep model

BackgroundThe utilization of decellularized extracellular matrix has gained considerable attention across numerous areas in regenerative research. Of particular interest is the human articular cartilage-derived extracellular matrix (hACECM), which presents as a promising facilitator for cartilage regeneration. Concurrently, the microfracture (MF) ​technique, a well-established marrow stimulation method, has proven efficacious in the repair of cartilage defects. However, as of the current literature review, no investigations have explored the potential of a combined application of hACECM and the microfracture technique in the repair of cartilage defects within a sheep model. HypothesisThe combination of hACECM scaffold and microfracture will result in improved repair of full-thickness femoral condyle articular cartilage defects compared to the use of either technique alone. Study designControlled laboratory study. MethodsFull-thickness femoral condyle articular cartilage defect (diameter, 7.0 ​mm; debrided down to the subchondral bone plate) were created in the weight-bearing area of the femoral medial and lateral condyles (n ​= ​24). All of defected sheep were randomly divided into four groups: control, microfracture, hACECM scaffold, and hACECM scaffold ​+ ​microfracture. After 3, 6 and 12 months, the chondral repair was assessed for standardized (semi-) quantitative macroscopic, imaging, histological, immunohistochemical, mechanics, and biochemical analyses in each group. ResultAt 3, 6 and 12 months after implantation, the gross view and pathological staining of regenerative tissues were better in the hACECM scaffold and hACECM scaffold ​+ ​microfracture groups than in the microfracture and control groups; Micro-CT result showed that the parameters about the calcified layer of cartilage and subchondral bone were better in the hACECM scaffold and hACECM scaffold ​+ ​microfracture groups than the others, and excessive subchondral bone proliferation in the microfracture group. The results demonstrate that human cartilage extracellular matrix scaffold alone is an efficient, safe and simple way to repair cartilage defects. ConclusionhACECM scaffolds combined with/without microfracture facilitate chondral defect repair. The translational potential of this articlePreclinical large animal models represent an important adjunct and surrogate for studies on articular cartilage repair, while the sheep stifle joint reflects many key features of the human knee and are therefore optimal experimental model for future clinical application in human. In this study, we developed a human articular cartilage-derived extracellular matrix scaffold and to verify the viability of its use in sheep animal models. Clinical studies are warranted to further quantify the effects of hACECM scaffolds in similar settings.

The Longer-Term Effects of a Single Bupivacaine Exposure on the Mechanical Properties of Native Cartilage Explants.

The purpose of this study was to determine the in vitro effects of a single exposure of bupivacaine on the mechanical properties of bovine cartilage explants at 3 weeks. Femoral condyle articular cartilage explants were aseptically harvested from juvenile bovine stifle joints before being exposed to chondrogenic medium containing 0.50% (wt/vol) bupivacaine, 0.25% (wt/vol) bupivacaine, or no medication (control) for 1 hour. Explants were then washed and maintained in culture in vitro for 3 weeks before testing. Cell viability, tensile and compressive mechanical properties, histological properties, and biochemical properties were then assessed. Explants exhibited a dose-dependent decrease in mean tensile Young's modulus with increasing bupivacaine concentration (9.86 MPa in the controls, 6.48 MPa in the 0.25% bupivacaine group [P = 0.048], and 4.72 MPa in the 0.50% bupivacaine group [P = 0.005]). Consistent with these results, collagen content and collagen crosslinking decreased with bupivacaine exposure as measured by mass spectrometry. Compressive properties of the explants were unaffected by bupivacaine exposure. Explants also exhibited a trend toward dose-dependent decreases in viability (51.2% for the controls, 47.3% for the 0.25% bupivacaine-exposed group, and 37.0% for the 0.50% bupivacaine-exposed group [P = 0.072]). Three weeks after 1-hour bupivacaine exposure, the tensile properties of bovine cartilage explants were significantly decreased, while the compressive properties remained unaffected. These decreases in tensile properties corresponded with reductions in collagen content and crosslinking of collagen fibers. Physicians should be judicious regarding the intra-articular administration of bupivacaine in native joints.

A Morphological Study of the Meniscus, Cartilage and Subchondral Bone Following Closed-Joint Traumatic Impact to the Knee

Post-traumatic osteoarthritis (PTOA) is a debilitating disease that is a result of a breakdown of knee joint tissues following traumatic impact. The interplay of how these tissues influence each other has received little attention because of complex interactions. This study was designed to correlate the degeneration of the menisci, cartilage and subchondral bone following an acute traumatic event that resulted in anterior cruciate ligament (ACL) and medial meniscus tears. We used a well-defined impact injury animal model that ruptures the ACL and tears the menisci. Subsequently, the knee joints underwent ACL reconstruction and morphological analyses were performed on the menisci, cartilage and subchondral bone at 1-, 3- and 6-months following injury. The results showed that the morphological scores of the medial and lateral menisci worsened with time, as did the tibial plateau and femoral condyle articular cartilage scores. The medial meniscus was significantly correlated to the medial tibial subchondral bone at 1 month (p = 0.01), and to the medial tibial cartilage at 3 months (p = 0.04). There was only one significant correlation in the lateral hemijoint, i.e., the lateral tibial cartilage to the lateral tibial subchondral bone at 6 months (p = 0.05). These data may suggest that, following trauma, the observed medial meniscal damage should be treated acutely by means other than a full or partial meniscectomy, since that procedure may have been the primary cause of degenerative changes in the underlying cartilage and subchondral bone. In addition to potentially treating meniscal damage differently, improvements could be made in optimizing treatment of acute knee trauma.

Assessing the Racial Differences in Q Angle Measurements in Relevance to Articular Cartilage of the Femoral Condyle: A Retrospective Ultrasound Study

The Q-angle is defined as the acute angle formed by the vectors for combined pull of the quadriceps femoris muscle and the patellar tendon. This study aimed to investigate the variations in Q angle with respect to race. Moreover, this study performed ultrasound to evaluate of the thickness of articular cartilage covering the medial and lateral femoral condyle in volunteers with an increased Q angle. The study included 487 Jordanian and 402 Malaysians with age range 18-23 years. Moreover, the study included 30 participants aged between 18 and 22 years, with a total of 15 volunteers with Q >14° and 15 patients with Q ≤14°. Both Q angle and condylar distance were measured by well-trained medical practitioners according to a well-established protocol. The thickness of articular cartilage covering the medial and lateral femoral condyle of the femoral bone was measured using ultrasound. Regardless of race, Q angle was greater in females. Furthermore, Q angle was significantly greater in Arab volunteers compared to Malay volunteers. Q angle significantly increase with increasing condylar distance in both races. Finally, the statistical analysis showed a significantly reduced thickness of articular cartilage on both medial and lateral femoral condyle (P = 0.05) in the Q >14° group. Multiple factors including race and condylar distance and even the articular cartilage of femoral condyle should be considered during the examination and management of knee fractures and condylar diseases.

Synthesizing Quantitative T2 Maps in Right Lateral Knee Femoral Condyles from Multicontrast Anatomic Data with a Conditional Generative Adversarial Network.

To develop a proof-of-concept convolutional neural network (CNN) to synthesize T2 maps in right lateral femoral condyle articular cartilage from anatomic MR images by using a conditional generative adversarial network (cGAN). In this retrospective study, anatomic images (from turbo spin-echo and double-echo in steady-state scans) of the right knee of 4621 patients included in the 2004-2006 Osteoarthritis Initiative were used as input to a cGAN-based CNN, and a predicted CNN T2 was generated as output. These patients included men and women of all ethnicities, aged 45-79 years, with or at high risk for knee osteoarthritis incidence or progression who were recruited at four separate centers in the United States. These data were split into 3703 (80%) for training, 462 (10%) for validation, and 456 (10%) for testing. Linear regression analysis was performed between the multiecho spin-echo (MESE) and CNN T2 in the test dataset. A more detailed analysis was performed in 30 randomly selected patients by means of evaluation by two musculoskeletal radiologists and quantification of cartilage subregions. Radiologist assessments were compared by using two-sided t tests. The readers were moderately accurate in distinguishing CNN T2 from MESE T2, with one reader having random-chance categorization. CNN T2 values were correlated to the MESE values in the subregions of 30 patients and in the bulk analysis of all patients, with best-fit line slopes between 0.55 and 0.83. With use of a neural network-based cGAN approach, it is feasible to synthesize T2 maps in femoral cartilage from anatomic MRI sequences, giving good agreement with MESE scans.See also commentary by Yi and Fritz in this issue.Keywords: Cartilage Imaging, Knee, Experimental Investigations, Quantification, Vision, Application Domain, Convolutional Neural Network (CNN), Deep Learning Algorithms, Machine Learning Algorithms© RSNA, 2021.

Characterization of the interleukin-17 effect on articular cartilage in a translational model: an explorative study

BackgroundOsteoarthritis (OA) is a progressive, chronic disease characterized by articular cartilage destruction. The pro-inflammatory cytokine IL-17 levels have been reported elevated in serum and synovial fluid of OA patients and correlated with increased cartilage defects and bone remodeling. The aim of this study was to characterize an IL-17-mediated articular cartilage degradation ex-vivo model and to investigate IL-17 effect on cartilage extracellular matrix protein turnover.MethodsFull-depth bovine femoral condyle articular cartilage explants were cultured in serum-free medium for three weeks in the absence, or presence of cytokines: IL-17A (100 ng/ml or 25 ng/ml), or 10 ng OSM combined with 20 ng/ml TNFα (O + T). RNA isolation and PCR analysis were performed on tissue lysates to confirm IL-17 receptor expression. GAG and ECM-turnover biomarker release into conditioned media was assessed with dimethyl methylene blue and ELISA assays, respectively. Gelatin zymography was used for matrix metalloproteinase (MMP) 2 and MMP9 activity assessment in conditioned media, and shotgun LC-MS/MS for identification and label-free quantification of proteins and protein fragments in conditioned media. Western blotting was used to validate MS results.ResultsIL-17RA mRNA was expressed in bovine full-depth articular cartilage and the treatment with IL-17A did not interfere with metabolic activity of the model. IL-17A induced cartilage breakdown; conditioned media GAG levels were 3.6-fold-elevated compared to untreated. IL-17A [100 ng/ml] induced ADAMTS-mediated aggrecan degradation fragment release (14-fold increase compared to untreated) and MMP-mediated type II collagen fragment release (6-fold-change compared to untreated). MS data analysis revealed 16 differentially expressed proteins in IL-17A conditioned media compared to untreated, and CHI3L1 upregulation in conditioned media in response to IL-17 was confirmed by Western blotting.ConclusionsWe showed that IL-17A has cartilage modulating potential. It induces collagen and aggrecan degradation indicating an upregulation of MMPs. This was confirmed by zymography and mass spectrometry data. We also showed that the expression of other cytokines is induced by IL-17A, which provide further insight to the pathways that are active in response to IL-17A. This exploratory study confirms that IL-17A may play a role in cartilage pathology and that the applied model may be a good tool to further investigate it.

Knee Arthroscopy: The “Crevice Sign,” a New Pathognomonic Sign for Unstable Posterior Medial Meniscal Tear in Anterior Cruciate Ligament–Deficient Knees

There has been increased emphasis on medial meniscus repair in the anterior cruciate ligament–reconstructed knee, as this improves stability. We describe an arthroscopic sign of an unstable medial meniscal tear that is diagnostic. The “crevice sign” is a longitudinal fissure located on the distal medial femoral condyle. In the anterior cruciate ligament–deficient knee, there is increased strain on the medial meniscus. A posterior longitudinal medial meniscal tear can occur at the time of the index injury or with subsequent instability events. During this injury, the knee pivots and the anterior edge of the unstable medial meniscus digs into the articular cartilage of the medial femoral condyle, resulting in a longitudinal split of the distal femoral condyle articular cartilage. If this sign is observed during arthroscopy, it is recommended that surgeons thoroughly probe the medial meniscus to ensure no pathology is missed.

Arthroscopic treatment of chondral lesions in varus knee in adults combined with corrective high tibial osteotomy

Objectives To document whether cartilage regeneration occurs in the degenerated medial compartment of arthritic knees in patients with varus malalignment after medial opening wedge high tibial osteotomy (MOWHTO) with concomitant cartilage procedures and to assess which predictive factors influence the clinical outcome. Patients and methods A total of 28 patients underwent MOWHTO between December 2016 and December 2018 in Al-Zahraa University Hospital for varus malalignment and medial osteoarthritis. Preoperative and postoperative assessments were done using American Knee Society’s Knee and Functional Scoring System. All patients were evaluated by arthroscopy before and ∼12 months after HTO. The International Cartilage Repair Society grading system was used for arthroscopic grading. Results At initial arthroscopy, two (7.1%) knees had grade II medial femoral condyle articular cartilage finding, seven (25%) knees had grade III findings, and 19 (67.9%) knees had grade IV findings. Only 20 cases had second-look arthroscopy, no regenerative change was found in 40% of knees, white scattering fibrocartilage was found in 55% of knees, and deterioration of the cartilage was observed in one (5%) case. Conclusion The degenerated cartilage could be partially or entirely covered by newly regenerated cartilage at 1 years after adequate correction of varus deformity by MOWHTO.

HOTAIR‐induced apoptosis is mediated by sponging miR‐130a‐3p to repress chondrocyte autophagy in knee osteoarthritis

Knee osteoarthritis (KOA) is a multifactorial disease characterized by the loss of articular cartilage. Hox transcript antisense intergenic RNA (HOTAIR) long non-coding RNA (lncRNA) is highly expressed in some cases of OA; however, its role in chondrocyte apoptosis in KOA and the mechanism by which HOTAIR mediates apoptosis in chondrocytes are not completely understood. Here, we evaluated the effects of HOTAIR on chondrocyte apoptosis in KOA. Our results showed that HOTAIR expression was significantly upregulated in cartilage tissues located at the femoral condyles or tibial plateaus of OA resection regions when compared with control regions in patients with normal non-weight-bearing area femoral condyle articular cartilage. Overexpression of HOTAIR caused a sharp increase in apoptosis rates and a reduction in the viability of chondrocytes. These effects were accompanied by the upregulation of Bax expression and the proteolytic cleavage of caspase 3 expression and downregulation of survivin and Bcl-2 expression. The silencing of HOTAIR produced the opposite effects. Moreover, the cartilaginous expression of miR-130a-3p was notably reduced in the OA resection regions of KOA patients. Luciferase assays showed that HOTAIR-adsorbed and reduced the levels of miR-130a-3p in chondrocytes. Further, inhibition of miR-130a-3p remarkably promoted the apoptosis of chondrocytes and repressed cell growth, while the silencing of HOTAIR could rescue the apoptosis mediated by miR-130a-3p inhibition. Chondrocyte autophagy was suppressed in a HOTAIR-dependent, miR-130a-3p inhibitor-mediated manner. Overall, our data revealed that aberrantly high expression of HOTAIR resulted in massive apoptosis events caused by the sponging of miR-130a-3p to suppress autophagy in chondrocytes, which, in turn, might trigger KOA. Therefore, inhibition of HOTAIR-mediated apoptosis might be a potential mechanism that can be targeted by gene therapy of KOA.

Particulated Juvenile Articular Cartilage (PJAC) Allograft for Treatment of Lateral Femoral Condyle defect in High-Performance Athletes

Background: A relatively new technology for the treatment of high grade articular cartilage lesions is the implantation of particulated articular cartilage obtained from a juvenile allograft donor (PJAC).1-2 Previous studies have reported the ability of juvenile chondrocytes to migrate from cartilage explants after being secured in a cartilage defect.3 There is little in the literature to use as a reference with respect to the use of PJAC for high grade articular cartilage lesion of the lateral femoral condyle after a failure of treatment with a microfracture in the high level athlete. Objective: The aim of this report is to describe the technique of PJAC transplantation for the treatment of chondral lesions of the lateral femoral condyle and to report the short term outcomes in the high performance athlete. Methods: We present a case report of two patients who were treated in our clinic in December 2014. Case 1: 16 year old female Division 1 university soccer player, who one year prior to our index surgery underwent microfractures of a symptomatic lateral femoral condyle articular cartilage lesion without relief. Cae 2: 29 year old male professional tennis player (case 2) with a recurrent, symptomatic chondral defect on the lateral femoral condyle. The player had undergone multiple arthroscopic procedures on the same knee following an injury sustained while playing in the Australian Open, including a surgery 8 months prior to our index operation that had included lateral meniscal tear repair and microfractures. PJAC procedure consists of a minimal debridement and chondroplasty, performed arthroscopically. For these central lateral femoral condyle lesions, a mini-arthrotomy is created along the lateral parapatellar longitudinal axis over a length of about 3 cm. With the chondral defect localized and prepared, a thin fresh layer of fibrin glue is then applied. The PJAC graft is equally distributed in the defect with space in between the fragments so as not over-fill the defect. Then, a new fibrin glue layer is placed to cover the graft. The overall construct remains just below the level of the normal articular surface. The knee is cycled through the range of motion to ensure that the tissue construct is stable. We present images of the cartilage defect after debridement and the allograft implantation procedure. In addition we will submit an instructional video performed on a knee specimen. Results: Outcomes measured were: IKDC, Lysholm, and Tegner knee scores together with arc of motion of the joint. After 28 months follow up, patients had gained complete range of motion and significantly decreased pain. Improvement for each outcome measure used is reported. Conclusions: PJAC transplantation offers pain relief and improved short term outcomes in high level performance athletes. Both of our patients are back to practicing their sport with notable improvement in symptoms. No complications have been noted. Long-term data is not yet available.

Human umbilical cord Wharton's jelly mesenchymal stem cells combined with an acellular cartilage extracellular matrix scaffold improve cartilage repair compared with microfracture in a caprine model

As a novel and promising seed cell, human umbilical cord Wharton's jelly mesenchymal stem cells (hWJMSCs) are widely applied in tissue engineering. However, whether hWJMSCs can better repair and regenerate the articular cartilage in big animals than microfracture (MF, a predominant clinical treatment strategy for damaged cartilage) is unclear. Evaluation of the validity, and safety of hWJMSCs in a caprine model with a full-thickness femoral condyle articular cartilage defect, compared with MF is required. After cultivation and identification, hWJMSCs were seeded in an acellular cartilage extracellular matrix (ACECM)-oriented scaffold to construct cell-scaffold complex. Six goats with full-thickness femoral condyle articular cartilage defects were randomized to MF (microfracture group, MFG) and cell-scaffold complexes (experimental group, EG). At 2 and 4 weeks, joint fluid was used to assess immuno-inflammatory responses. At 6 and 9 months, all goats were euthanized for assessment of morphology, and magnetic resonance imaging (MRI), histology staining, and evaluation of the elasticity modulus and glycosaminoglycan (GAG) contents of the repaired regions. There were no significant differences between the two groups in immuno-inflammatory parameters. MRI demonstrated higher-quality cartilage and complete subchondral bone at defect sites in the EG at 9 months. Histological staining showed that extracellular cartilage, cartilage lacuna and collagen type II levels were higher in the EG compared to the MFG, while the EG exhibited a higher elasticity modulus. The hWJMSCs-ACECM scaffold complex achieved better quality repair and regeneration of hyaline cartilage without cartilage-inducing factor, while retaining the structure and functional integrity of the subchondral bone, compared with MF.

Topographic Analysis of the Distal Femoral Condyle Articular Cartilage Surface: Adequacy of the Graft from Opposite Condyles of the Same or Different Size for the Osteochondral Allograft Transplantation.

To analyze the topography of the opposite condyle to treat focal femoral condyle articular defects with an osteochondral allograft (OCA). Three groups were created: Group 1, same condyle with same width; Group 2, opposite condyle with same width; Group 3, opposite condyle with different width. Computed tomography (CT) of 22 cadaveric femoral hemi-condyles was used to create 3-dimensional CT models that were exported into point-cloud models. Three zones of the donor condyle (anterior, middle, and posterior) were quantified. Four defect sizes were created (15, 18, 23, 25 mm) at the weight-bearing region. The defect was moved throughout each donor condyle zone and the least distance was calculated, defined as the shortest distance between the defect and the donor condyle. The mean least distance increased with larger defect size in all groups, yet there was a less than 0.2 mm difference in the least distance among defect sizes. The 15, 18, and 23 mm defect models in Group 1 exhibited greater least distances at the anterior than middle and posterior zones. The 15 mm defect model exhibited greater least distance at the anterior zone than posterior zone in Group 3. However, there was a less than 0.05 mm difference in the mean least distance between zones. There was no significant difference in the least distance between groups. OCAs from opposite condyles yield similar topographic matching to OCAs from the same condyles, suggesting that opposite condyles can be utilized. Clinical correlation and outcomes are necessary.

Оценка численности хондроцитов в суставном хряще при дистракционном остеосинтезе голени в комбинации с накостной пластиной

Introduction The number of chondrocytes in the articular cartilage of the femoral condyles and talus junction surface in the conditions of distraction osteosynthesis of the tibia with the Ilizarov apparatus combined with plating was estimated. Material and methods Seven dogs underwent tibial lengthening at a daily rate of 1 mm for 4 steps and to 14–16 % of the initial length of the segment with the use of the Ilizarov apparatus and plating. Stages of the study were days 30 and 90 in the fixation phase when only plating was left. Histomorphometry of semi-thin sections of the articular cartilage was carried out with the help of an Opton photomicroscope (Germany), DiaMorf software complex (Russia) and VideoTest-Master morphology program. The proportion of chondrocytes (N ch, %), the proportion of empty lacunae (NN em.lac, %), and isogenic groups (NN is.gr, %) were determined in the total sample volume of 200 lacunae. A control group was articular cartilage of five intact dogs. Results The articular cartilage of both articular surfaces retained the zonal structure. Disorder in the homogeneity of the superficial part of the surface zone and destruction of a part of chondrocytes were noted. In the articular cartilage of the femoral condyles, the Nch value was lower than in the control animals by 5.74 %. NN em.lac was increased 2.3 times while NN is.gr values decreased to 2.06 % in the femoral condyle articular cartilage after 30 days of fixation period with the plate. After 90 days of fixation, the N ch values were lower with respect to the controls by 3.73 %. Low values of NN is.gr (4.3 %) and high values of NN em.lac (27.54 %) were maintained. In the articular cartilage of the talus, N ch was lower than in the control group by 1.98 %; NN em.lac increased 1.5 times and NN is.gr decreased to 4.7 % relative to controls after 30 days of fixation. After 90 days, the value of NN em.lac remained at the same level as in the previous experiment stage. The values of NN is.gr were comparable with the control group. Conclusion The technique of distraction osteosynthesis of the tibia in combination with plating is of low traumatic effect on the adjacent joints. A comparative analysis of quantitative parameters of the articular cartilage revealed that the most vulnerable site was the articular cartilage of the femoral condyles.

Osteochondral Allograft Transplantation for Treatment of Medial Femoral Condyle Defect

Chondral lesions of the knee can affect the young, active population, thereby causing severe morbidity and a large economic burden. Although numerous approaches have been described in the literature, restoration of hyaline cartilage has yet to be shown. Specifically, larger, full-thickness cartilage defects remain a challenge. This Technical Note details our technique for biologic unicompartmental osteochondral allograft transplantation for the treatment of large femoral condyle articular cartilage defects.

Isolated ACL versus multiple knee ligament injury: associations with patient characteristics, cartilage status, and meniscal tears identified during ACL reconstruction

ABSTRACTObjectives: The objectives of this study were to determine (1) if patients undergoing reconstruction of an isolated anterior cruciate ligament (ACL) tear had different characteristics (age, gender, body mass index [BMI]) than patients undergoing ACL reconstruction (ACLR) with multiple knee ligament (MKL) tears and (2) whether there was a difference in prevalence of articular cartilage injury and meniscus tears between these two groups.Methods: Patients undergoing primary ACLR between February 2005 and June 2013 were identified through an ACLR registry. Patients were grouped by whether they had an isolated ACL tear or an ACL tear associated with another knee ligament tear. The study cohort was analyzed to identify differences in patient characteristics and cartilage/meniscus injury patterns between the groups.Results: Of the 21,377 ACLR cases enrolled in the registry during the study period, 2.5% (n = 549) had MKL tears. The MKL group had more males (73.2% vs. 62.8%, p < 0.001) than the isolated ACL group. The MKL group also had a higher percentage of patients with a BMI greater than 30 (31.1% vs. 22.7%, p = 0.0002). When adjusting for these variables, any articular cartilage injury was equal in the two groups (OR = 1.01, CI 0.82–1.25, p = 0.922), while medial femoral condyle injury was less common in the MKL group (OR = 0.73, CI = 0.56–0.07, p = 0.28). The likelihood of any meniscus tear was lower in the MKL group (OR = 0.56, CI = 0.47–0.67, p < 0.001) as was the likelihood of medial meniscus tears (OR = 0.53, CI = 0.44–0.65, p < 0.001).Conclusions: When comparing patients with MKL tears versus isolated ACL tears at ACLR, there was a higher percentage of males and patients with BMI over 30 in the MKL group. Medial femoral condyle articular cartilage injury, any meniscus tear, and medial meniscus tears were less common in patients with MKL injury compared to patients with isolated ACL tears.

Костное сращение и структурные изменения суставного хряща после срочного и отсроченного остеосинтеза антеградным блокирующим интрамедуллярным стержнем переломов диафиза бедра

Background Antegrade locked intramedually nailing (IMN) is considered to be a method of choice for repair of femoral shaft fractures. We studied the articular cartilage of the canine femoral condyles in the conditions of immediate and delayed antegrade IMN to reveal whether timing of operation results in any structural changes in the cartilage tissue. Material and methods Femoral shaft fractures were modelled in 12 adult mongrel dogs and fixed using antegrade IMN immediately after the injury in group 1 (n = 6) and four days after the injury in group 2 (n = 6). Five dogs were intact. Results In group 1, fractures united after 42 days but in group 2 the union was seen in the radiographs only by day 70. Unified bone marrow cavity and cortex were formed by day 70 in group 1 while in group 2 it was seen only by day 100. The histological study showed that the structure of the articular cartilage of the femoral condyles was not damaged in group 1 at all time points. The changes were the decrease in the cartilage thickness and in the volumetric density of condrocytes. In group 2, the cartilage of the femoral condyles featured defibration of the articular surface that was accompanied by breakage of the basophilic line integrity and penetration of vessels into the cartilage. Conclusion Delayed antegrade locked IMN provoked destructive changes in the articular cartilage of the femoral condyles and decreased chondrocyte proliferation. We suppose that delayed IMN of a femoral shaft fracture might cause initiation or deteriorate the existing knee osteoarthritis. Level of evidence: IV.

Comparison of Results of Medial Opening-Wedge High Tibial Osteotomy With and Without Subchondral Drilling

The purposes of this study were to compare the results of medial opening-wedge high tibial osteotomy (MOWHTO) with and without subchondral drilling and to assess the formation of fibrocartilage at 2 years postoperatively. Patients were divided into 2 groups. Thirty knees were treated with osteotomy and subchondral drilling (group 1), and 31 knees were treated with osteotomy alone (group 2). Clinical evaluations were performed by use of Knee Society scores preoperatively and at 2 years postoperatively. For evaluation of cartilage degeneration, the International Cartilage Repair Society grading system was used for arthroscopic grading on initial arthroscopy during high tibial osteotomy. The patients underwent a second-look arthroscopic evaluation of the articular cartilage at the time of removal of the plate, an average of 2years after the initial osteotomy. For evaluation of formation of fibrocartilage on second-look arthroscopy, the articular cartilage was classified as having either no change from initial surgery (grade I) or white scattering with fibrocartilage, partial coverage with fibrocartilage, or even coverage with fibrocartilage (grade II). In addition, maturation of the appearance of the cartilage was defined. The appearance was considered mature if the chondral defects were evenly covered with fibrocartilage. It was considered immature if there was white scattering or only partial coverage with fibrocartilage. In group 1 the mean Knee Society knee score and function score were 67.3 ± 8.2 points and 66.5 ± 14.3 points, respectively, preoperatively. At 2 years postoperatively, they improved to 91.2 ± 6.4 and 92.8 ± 10.0, respectively (P= .001 and P= .001, respectively). In group 2 the mean Knee Society knee score and function score were 63.7 ± 13.9 points and 66.8 ± 9.1 points, respectively, preoperatively. At 2 years postoperatively, they improved to 92.5 ± 5.3 points and 92.2 ± 8.0 points, respectively (P= .001 and P= .001, respectively). There were no significant differences in the postoperative Knee Society knee score and function score at 2 years' follow-up between the groups (P= .389 and P= .806, respectively). Grade II regeneration was achieved in the medial femoral condyle articular cartilage in 100% of knees in group 1 and 94% of knees in group 2 (P= .492). Maturation of the cartilage was found in the medial femoral condyle articular cartilage in 10% of knees in group 1 and 3% of knees in group 2 (P= .354). There was no significant difference in the formation of fibrocartilage between the groups. Subchondral drilling had no effect on the outcome at 2 years after MOWHTO. In addition, there was no significant difference in the formation of fibrocartilage with or without subchondral drilling. Therefore subchondral drilling is not necessary after MOWHTO. Level III, retrospective comparative study.

Structural reorganization of the knee joint cartilage and synovium during diaphyseal femoral fracture management using intramedullary locked nails ^perime^al and morphological study)

The purpose - to study structural changes in knee articular cartilage and synovial membrane during locking intramedullary osteosynthesis of femoral fractures. Material and methods. The study tested structural changes in the articular cartilage of the femoral condyles and synovium during femoral fracture repair under the conditions of intramedullary locked nailing. Transverse diaphyseal femoral fractures were modeled in 12 adult mongrel dogs. Synovitis severity was assessed with a V. Krenn scale. Wilcoxon Test was used for testing hypothesis. Results. In the first group (n = 6) fractures were fixed with locked intramedullary nails ILoc (Biomedtrix, USA), while the same type of fixation in group 2 (n = 6) was performed on 4 th day postoperatively after reduction by skeletal traction. It was revealed that in the first group a unified medullary cavity was seen by day 70 and the cortical layer at the fracture site approximated to the condition of the uninjured bone in intensity of bone formation and thickness. These featured were observed in the second group only by day 100. The histological study showed that the structure of the femoral condyle articular cartilage was regular in the first group but its changes were reduced thickness and reduced volumetric density of chondrocytes that might result due to disturbed trophical condition. In the second group the articular cartilage fibres tended to disintegrate on the surface that was accompanied by disturbed integrity of the basophil line and penetration of the vessels into the cartilage. Moreover, the cartilage destruction progressed as the experiment continued and chondrocyte proliferation sharply decreased. Synovitis was considerably expressed. The data obtained in the second group proved high risk of developing osteoarthrosis.

Second-Look Arthroscopic Assessment of Cartilage Regeneration After Medial Opening-Wedge High Tibial Osteotomy

The purposes of this study were to evaluate regeneration of the articular cartilage after medial opening-wedge high tibial osteotomy for knees with medial-compartment osteoarthritis and to assess the clinical outcome and cartilage regeneration according to the postoperative limb alignment at 2 years postoperatively. The study involved 159 knees in 159 patients. For evaluation of cartilage degeneration, the International Cartilage Repair Society grading system was used for arthroscopic grading on initial arthroscopy during high tibial osteotomy. The patients underwent a second-look arthroscopic evaluation of the articular cartilage at the time of removal of the plate, an average of 2 years after the initial osteotomy. For evaluation of cartilage regeneration, the articular cartilage was classified into 2 stages as no regenerative change (grade 1) or white scattering with fibrocartilage, partial coverage with fibrocartilage, or even coverage with fibrocartilage (grade 2) on second-look arthroscopy. Maturation of the cartilage regeneration was defined as even coverage with fibrocartilage. "Immaturation" of the cartilage regeneration was defined as white scattering with fibrocartilage or partial coverage with fibrocartilage. Clinical evaluations were performed by use of Knee Society scores preoperatively and at 2 years postoperatively. We divided the knees into 3 groups according to the postoperative limb alignment. Group A comprised knees with a mechanical tibiofemoral angle of 0° or less. Group B comprised knees with a mechanical tibiofemoral angle greater than 0° and less than 6°. Group C comprised knees with a mechanical tibiofemoral angle of 6° or greater. Grade 2 regeneration was achieved in the medial femoral condyle articular cartilage in 92% of knees and in the medial tibial plateau articular cartilage in 69% of knees. Maturation of the cartilage regeneration was found in the medial femoral condyle articular cartilage in 4% of knees and in the medial tibial plateau articular cartilage in 1% of knees. At follow-up, no significant differences were seen between clinical outcomes and initial cartilage degeneration (P = .338) or cartilage regeneration (P = .699). Regeneration of the medial femoral condyle articular cartilage was found in 75% of group A knees, 95% of group B knees, and 92% of group C knees. Significant differences were seen between cartilage regeneration and clinical outcomes (P = .001), as well as postoperative limb alignment (P = .018). Clinical and regeneration results were better in group B than in groups A and C. The degenerated cartilage of the medial femoral condyle and medial tibial plateau could be partially or entirely covered by newly regenerated cartilage at 2 years after adequate correction of varus deformity by medial opening-wedge high tibial osteotomy without cartilage regeneration strategies. Level IV, therapeutic case series.