Cartilage defects represent an increasing pathology among active individuals that affects the ability to contribute to sports and daily life. Cell therapy, such as autologous chondrocyte implantation ...(ACI), is a widespread option to treat larger cartilage defects still lacking standardization of in vitro cell culture parameters. We hypothesize that mRNA expression of cytokines and proteases before and after ACI is influenced by in vitro parameters: cell-passage, cell-density and membrane-holding time. Knee joint articular chondrocytes, harvested from rabbits (
= 60), were cultured/processed under varying conditions: after three different cell-passages (P1, P3, and P5), cells were seeded on 3D collagen matrices (approximately 25 mm³) at three different densities (2 × 10⁵/matrix, 1 × 10⁶/matrix, and 3 × 10⁶/matrix) combined with two different membrane-holding times (5 h and two weeks) prior autologous transplantation. Those combinations resulted in 18 different in vivo experimental groups. Two defects/knee/animal were created in the trochlear groove (defect dimension: ∅ 4 mm × 2 mm). Four identical cell-seeded matrices (CSM) were assembled and grouped in two pairs: One pair giving pre-operative in vitro data (CSM-i), the other pair was implanted in vivo and harvested 12 weeks post-implantation (CSM-e). CSMs were analyzed for TNF-α, IL-1β, MMP-1, and MMP-3 via qPCR. CSM-i showed higher expression of IL-1β, MMP-1, and MMP-3 compared to CSM-e. TNF-α expression was higher in CSM-e. Linearity between CSM-i and CSM-e values was found, except for TNF-α. IL-1β expression was higher in CSM-i at higher passage and longer membrane-holding time. IL-1β expression decreased with prolonged membrane-holding time in CSM-e. For TNF-α, the reverse was true. Lower cell-passages and lower membrane-holding time resulted in stronger TNF-α expression. Prolonged membrane-holding time resulted in increased MMP levels among CSM-i and CSM-e. Cellular density was of no significant effect. We demonstrated cytokine and MMP expression levels to be directly influenced by in vitro culture settings in ACI. Linearity of expression-patterns between CSM-i and CSM-e may predict ACI regeneration outcome in vivo. Cytokine/protease interaction within the regenerate tissue could be guided via adjusting in vitro culture parameters, of which membrane-holding time resulted the most relevant one.
Purpose The purpose of this study was to evaluate the mid- and long-term efficacy of the arthroscopic patellar release (APR) in a representative number of competitive athletes. Methods This ...prospective study included 35 competitive athletes who underwent APR for treatment of chronic refractory patellar tendinopathy. The minimum follow-up period was 24 months. Preoperatively and at follow-up, we measured the Swedish Victorian Institute of Sport Assessment for Patella (VISA-P) and modified Blazina score for assessment of functional outcome. The patients rated their subjective knee function (0% to 100%) and maximum pain during exercise on a visual analog scale (0 to 10 points). We inquired about time required for full return to sports. Results Thirty athletes (27 male individuals, 3 female individuals) were available for clinical examination after a mean follow-up period of 4.4 years (σ = 3.0 years). The follow-up rate was 30 of 35 (86%). Mean age at surgery was 27.6 years (σ = 7.4). The mean VISA-P score improved from 57.3 (σ = 11.4) to 95.1 (σ = 8.2) and the mean Blazina score improved from 4.0 (σ = 0.8) to 0.3 (σ = 0.7). Average subjective knee function improved from 48.8% (σ = 18.5%) to 90.5% (σ = 9.8%). The mean pain level decreased from 5.7 (σ = 1.1) to 0.6 (σ = 1.2%). All changes were significant ( P < .01). Twenty-three (76.7%) athletes were able to perform sports at previous levels without any symptoms. The mean time required for full return to sports was 4.4 months (1.5 to 12.0 months; σ = 3.3). Less pronounced symptoms recurred in 3 (10%) athletes. Conclusions After APR, 97% of patients obtained excellent or good functional outcomes with a mean follow-up of 4.4 years. Three of 4 athletes achieved asymptomatic previous sports levels, returning to full sports at an average of 4.4 months. Symptoms partially recurred in 10% of participants. Level of Evidence Level IV: prospective therapeutic case series.
Clouds play an important role in weather and climate. Therefore, it is important to quantify the dominant processes that influence cloud formation and dissolution. In this study, diagnostics of the ...relative humidity tendency in the ECHAM6 GCM are used to quantify the contribution of different atmospheric processes to the change in relative humidity and thus to quantify their impact on clouds. In the model, we find that the dominant processes are stratiform cloud microphysics, large-scale adiabatic horizontal advection and vertical motion, and cumulus convection. Tendencies calculated based on monthly mean fields approximate the monthly averages of instantaneous tendencies to within 50% in the mid-latitudes and 25% elsewhere. The correlation between the relative humidity tendencies and mid-tropospheric vertical velocity ω
500
is analysed. The most important processes for cloud formation are tightly correlated with ω
500
; the monthly mean vertical velocity in most cases appears qualitatively useful to characterise the cloud-forming and cloud-dissipating processes.
Transfusion of platelet concentrates represents an important treatment for various bleeding complications. However, the short half-life and frequent contaminations with bacteria restrict the ...availability of platelet concentrates and raise a clear demand for platelets generated ex vivo. Therefore, in vitro platelet generation from megakaryocytes represents an important research topic. A vital step for this process represents accurate analysis of thrombopoiesis and proplatelet formation, which is usually conducted manually. We aimed to develop a novel method for automated classification and analysis of proplatelet-forming megakaryocytes in vitro. After fluorescent labelling of surface and nucleus, MKs were automatically categorized and analysed with a novel pipeline of the open source software CellProfiler. Our new workflow is able to detect and quantify four subtypes of megakaryocytes undergoing thrombopoiesis: proplatelet-forming, spreading, pseudopodia-forming and terminally differentiated, anucleated megakaryocytes. Furthermore, we were able to characterize the inhibitory effect of dasatinib on thrombopoiesis in more detail. Our new workflow enabled rapid, unbiased, quantitative and qualitative in-depth analysis of proplatelet formation based on morphological characteristics. Clinicians and basic researchers alike will benefit from this novel technique that allows reliable and unbiased quantification of proplatelet formation. It thereby provides a valuable tool for the development of methods to generate platelets ex vivo and to detect effects of drugs on megakaryocyte differentiation.
Several different surgical options are available to address cartilage lesions. Lately, autologous minced cartilage procedure has been gaining in popularity as a chondrocyte based, simple, ...single-staged and cost-effective surgical technique.
The aim of this review is to provide an overview of the current evidence supporting chondrocyte based, single-stage cartilage repair with a focus on the technique of autologous minced cartilage implantation.
To date only limited evidence exists for single staged, autologous minced cartilage procedure. In vitro and animal studies show induction of de novo production of extracellular matrix, chondrocyte outgrowth, proliferation, and differentiation with encouraging tissue generation. Biological, histological and immunohistological data seem comparable to 2-stage autologous chondrocyte implantation. Preliminary, short-term clinical data indicate good clinical and functional results with low complication and revision rates. Clinical outcomes in the short term seem comparable to those resulting from autologous chondrocyte implantation .
Single-stage autologous minced cartilage repair is a simple and effective cartilage repair option. This technique has strong biologic, economic and clinical potential. More high-level, long-term comparative trials with larger patient cohorts are needed to allow for comparison with other cartilage repair techniques and to determine the implant durability.
Purpose. Reliable data about in vivo regulation of cytokines in early ankle osteoarthritis (OA) are still missing. Methods. 49 patients with a mean age of 33 ± 14 years undergoing an arthroscopy of ...the ankle with different stages of chronic OA were prospectively included in a clinical trial. Lavage fluids were analyzed by ELISA. Additionally, clinical parameters and scores (FFI, CFSS, and AOFAS) were evaluated and supplemented by the Kellgren Lawrence Score (KLS) and the ankle osteoarthritis scoring system (AOSS). Results. ICRS grading of cartilage damage, previous operations, and duration of complains were strong indicators for OA progress and showed correlations to age, clinical scores, validated KLS, and AOSS ( P < 0.04 ). Systemic and intraarticular inflammatory parameters were low in all patients. Biochemically, aggrecan and BMP-7 positively indicated OA with statistically significant associations with duration of symptoms, FFI, AOFAS, and KLS ( P < 0.04 ). In contrast, BMP-2 levels showed statistically significant negative correlations to aggrecan or BMP-7 concentrations, which is in line with the negative association with ICRS score and KLS and the positive correlation with FFI ( P < 0.03 ). Conclusions. We were able to identify different key markers of OA in the ankle as aggrecan, BMP-7, and BMP-2, offering starting points for new ways in diagnostics and interventional strategies.
Cartilage defects in the knee are being diagnosed with increased frequency and are treated with a variety of techniques. The aim of any cartilage repair procedure is to generate the highest tissue ...quality, which might correlate with improved clinical outcomes, return-to-sport, and long-term durability. Minced cartilage implantation (MCI) is a relatively simple and cost-effective technique to transplant autologous cartilage fragments in a single-step procedure. Minced cartilage has a strong biologic potential since autologous, activated non-dedifferentiated chondrocytes are utilized. It can be used both for small and large cartilage lesions, as well as for osteochondral lesions. As it is purely an autologous and homologous approach, it lacks a significant regulatory oversight process and can be clinically adopted without such limitations. The aim of this narrative review is to provide an overview of the current evidence supporting autologous minced cartilage implantation.
Objective
To design a simple magnetic resonance (MR)–based assessment system for quantification of osteochondral defect severity prior to cartilage repair surgery at the knee.
Design
The new scoring ...tool was supposed to include 3 different parameters: (1) cartilage defect size, (2) depth/morphology of the cartilage defect, and (3) subchondral bone quality, resulting in a specific 3-digit code. A clearly defined numeric score was developed, resulting in a final score of 0 to 100. Defect severity grades I through IV were defined. For intra- and interobserver agreement, defects were assessed by 2 independent readers on preoperative knee MR images of n = 44 subjects who subsequently received cartilage repair surgery. For statistical analyses, mean values ± standard deviation (SD), interclass correlation coefficients (ICC), and linear weighted kappa values were calculated.
Results
The mean total Area Measurement And DEpth & Underlying Structures (AMADEUS) score was 48 ± 24, (range, 0-85). The mean defect size was 2.8 ± 2.6 cm2. There were 36 of 44 full-thickness defects. The subchondral bone showed defects in 21 of 44 cases. Kappa values for intraobserver reliability ranged between 0.82 and 0.94. Kappa values for interobserver reliability ranged between 0.38 and 0.85. Kappa values for AMADEUS grade were 0.75 and 0.67 for intra- and interobserver agreement, respectively. ICC scores for the AMADEUS total score were 0.97 and 0.96 for intra- and interobserver agreement, respectively.
Conclusions
The AMADEUS score and classification system allows reliable severity encoding, scoring and grading of osteochondral defects on knee MR images, which is easily clinically applicable in daily practice.
Purpose
There is only limited information on those patients who fail following microfracture treatment at the knee joint. Evaluation was made of factors associated with treatment failure and clinical ...outcome assessment among this collective.
Methods
The study included a total of 560 patients who had previously undergone microfracture for the treatment of symptomatic knee joint cartilage lesions. For the remainder of this study, inclusion criteria were patients that underwent reoperation at the initially operated knee joint (index knee) due to symptoms related to the primary site of microfracture intervention (failure patients) with a minimum postoperative follow-up of 2 years. The remaining cohort of patients served as internal control (non-failure patients). Chart reviews were performed to identify patient and defect characteristics. Patients were evaluated for postoperative Lysholm knee scores, Tegner activity scale, as well as preoperative and postoperative numeric analogue scales (NAS) for function and pain (10 = highest possible function, no pain).
Results
A total of 454/560 (81.1 %) subjects were completely evaluated. Overall, 123/454 patients (26.9 %) (age at operation 43.9 ± 14.1 years, 56 female, BMI 25.8 ± 3.6, 30 smokers, 61.1 ± 68.3 month symptom duration, postoperative follow-up 5.0 ± 2.1) met the inclusion criteria. The postoperative Lysholm score was 63.0 ± 24.6 and the Tegner score was 4.0; NAS function improved from 2.8 ± 1.8 to 4.8 ± 2.2 (
P
< 0.001), and NAS pain improved from 3.2 ± 2.1 to 5.0 ± 2.4 (
P
< 0.001). Exclusively, the overall defect size/knee joint was smaller (
P
= 0.006), postoperative follow-up was longer (
P
= 0.002), and existense of previous surgery (77.2 vs. 51.6 %,
P
< 0.001) was more frequent in failure subjects when comparing to non-failure patients (
n
= 331). The overall clinical outcome among failure subjects was significantly worse when comparing to non-failure subjects. Regression analysis identified that lower preoperative NAS values, being a smoker, and patello-femoral lesions were associated with a higher probability of reoperation.
Conclusion
Within the collective presented here, microfracturing was associated with a high frequency of reoperation. Clinical outcome is worse when compared with that of patients without reoperation. Specific parameters can be identified that increase the eventuality of failure following microfracture treatment.
Level of evidence
IV.
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