Influence of leg axis alignment on MRI T2* mapping of the knee in young professional soccer players.

BACKGROUND: Investigation of the association between leg axis alignment and biochemical MRI in young professional soccer players in order to identify a potential influence of the leg axis on cartilage regions at risk. METHODS: Sixteen professional soccer players (21 ± 3 years) underwent static and dynamic leg axis analysis via radiation free DIERS formetric 4 D as well as 3-T MRI examination of both knees. Quantitative T2* mapping of the knee cartilage was performed and T2* values were evaluated as 144 regions of interest. Subgroup analysis was performed in players with severe varus alignment (> 6°). RESULTS: Analysis of the leg axis geometry revealed a mean static alignment of 6.6° ± 2.5 varus and a mean dynamic alignment of 5.1° ± 2.6 varus. Quantitative T2* mapping showed significantly increased T2* values in the superficial cartilage layer compared to the deeper region (p < 0.001) as well as a significant increase in relaxation times in the femoral cartilage from anterior to intermediate to posterior (p < 0.001). Combination of both methods revealed a significant correlation for the degree of varus alignment and the femoral, posterior, deep region of the medial knee compartment (r = 0.4; p = 0.03). If severe varus alignment was present this region showed a significant increase in relaxation time compared to players with a less pronounced leg axis deviation (p = 0.003). CONCLUSION: This study demonstrates that varus alignment in young soccer players is associated with elevated T2* relaxation times in the deep cartilage layer of the medial, posterior, femoral compartment and might therefore be a contributing factor in the early pathogenesis of manifest cartilage lesions. Therefore, these findings should be considered in the development of preventive training programs.

gagCEST imaging at 3 T MRI in patients with articular cartilage lesions of the knee and intraoperative validation.

OBJECTIVE: The aim of this study was to compare glycosaminoglycan chemical exchange saturation transfer (gagCEST) of knee cartilage with intraoperative results for the assessment of early osteoarthritis (OA) and to define gagCEST values for the differentiation between healthy and degenerated cartilage. DESIGN: Twenty-one patients with cartilage lesions or moderate OA were examined using 3 T Magnetic Resonance Imaging (MRI). In this prospective study, regions of interest (ROIs) were examined by a sagittal gagCEST analysis and a morphological high-resolution three-dimensional, fat-saturated proton-density space sequence. Cartilage lesions were identified arthroscopically, graded by the International Cartilage Repair Society (ICRS) score in 42 defined ROIs per patient and consecutively compared with mean gagCEST values using analysis of variance and Spearman's rank correlation test. Receiver operating characteristics (ROC) curves were applied to identify gagCEST threshold values to differentiate between the ICRS grades. RESULTS: A total of 882 ROIs were examined and graduated in ICRS score 0 (67.3%), 1 (25.2%), 2 (6.2%) and the merged ICRS 3 and 4 (1.0%). gagCEST values decreased with increasing grade of cartilage damage with a negative correlation between gagCEST values and ICRS scores. A gagCEST value threshold of 3.55% was identified to differentiate between ICRS score 0 (normal) and all other grades. CONCLUSIONS: gagCEST reflects the content of glycosaminoglycan and might provide a diagnostic tool for the detection of early knee-joint cartilage damage and for the non-invasive subtle differentiation between ICRS grades by MRI even at early stages in clinical practice.

Potential predictive value of axial T2 mapping at 3 Tesla MRI in patients with untreated patellar cartilage defects over a mean follow-up of four years.

OBJECTIVE: The objective was to demonstrate the potential of axial T2 mapping for quantification of untreated early-stage patellar cartilage lesions over time and to assess its capability as a potential predictive marker for future progression. STUDY DESIGN & METHODS: Thirty patients (mean age, 36.7 ± 11.1 years; 16 males), with early-stage patellar cartilage defects (≤ICRS grade 2) at baseline and no treatment during follow up (4.0 ± 1.6 years) were enrolled. Morphological cartilage changes over time were subdivided into a Progression, Non-Progression Group and Regression Group. Quantitative analysis of cartilage defects and healthy reference was performed by means of global and zonal T2 mapping (deep and superficial cartilage T2 values) at both time points. Statistical evaluation included analysis of variance (ANOVA), paired t Test's and ROC analysis. RESULTS: The Progression Group (N = 11) had significantly higher global T2 values at baseline (57.4 ± 7.8 ms) than patients without (N = 17) (40.6 ± 6.9 ms) (P < 0.01). Furthermore the Non-Progression Group showed only a minor increase in global T2 relaxation times to 43.1 ± 7.9 ms (P = 0.07) at follow up, whereas in the progression group global (68,7 ± 19 ms: P = 0.02) and superficial T2 values (65,8 ± 8.2-79.8 ± 24.4 ms; P = 0.03) increased significantly. T2 values for healthy reference cartilage remained stable. In 2 patients an improvement in ICRS grading was observed (Regression Group) with decreasing T2 values. The ROC analysis showed an area under the curve of 0.92 (95%CI 0.82-1.0). At a cut-off value of 47.15 ms, we found a sensitivity of 92% (false-positive rate of 18%) for future progression of cartilage defects. CONCLUSIONS: This study provides evidence regarding the possible potential of axial T2 mapping as a tool for quantification and prediction of patellar cartilage defect progression in untreated defects.

[Prevalence of dermatomycoses in professional football players : A study based on data of German Bundesliga fitness check-ups (2013-2015) compared to data of the general population]. / Prävalenz von Dermatomykosen bei Profifußballspielern : Untersuchung im Rahmen der Bundesligatauglichkeitsuntersuchung (2013­2015) im Vergleich mit Daten der Allgemeinbevölkerung.

BACKGROUND: The prevention, early diagnosis and treatment of onychomycosis is of great importance for professional athletes to avoid physical limitations by complications. So far, there is only little data on the prevalence of dermatomycosis in professional athletes. OBJECTIVES: The aim of the study was to detect the prevalence of dermatomycosis in professional football players compared to the general population. MATERIALS AND METHODS: The prospective, non-interventional, controlled study on the prevalence of dermatomycosis in professional football players was carried out on football players of a German Bundesliga team compared with a previously studied, equivalently aged German working population. A questionnaire survey, a dermatological check-up and a microbiological detection of pathogens in cases of suspicion were performed. RESULTS: Data of 84 football players (n = 45 in 2013; n = 39 in 2015) were compared to data of n = 8186 male employees between 17 and 35 years of age. In the group of athletes, there were findings of 60.7% onychomycosis, 36.9% of tinea pedis and 17.8% of pityriasis versicolor. In the group of the age-equivalent general German working population the findings were: onychomycosis 3.3%, tinea pedis 3.2%, pityriasis versicolor 1.4%. CONCLUSION: Our study shows a clearly higher risk for fungal diseases of the skin especially on the feet of professional football players. The results show a necessity for elucidation within prevention and the establishment of an appropriate therapy of dermatomycosis for professional football players.

Intraoperative validation of quantitative T2 mapping in patients with articular cartilage lesions of the knee.

OBJECTIVE: The aim of this study was to compare T2 relaxation times of knee cartilage with intraoperative results for the assessment of early osteoarthritis (OA) and to define T2 values for the differentiation between healthy and degenerated cartilage. DESIGN: Twenty-one patients with cartilage lesions or moderate OA were examined using 3T magnetic resonance imaging (MRI). In this prospective study, a total of 882 regions of interest (ROIs) were examined by a sagittal, multi-echo, spin-echo T2 sequence and a morphological high-resolution three-dimensional, fat-saturated proton-density space sequence. Cartilage lesions were identified arthroscopically, graded by the International Cartilage Repair Society (ICRS) score in 42 defined ROIs per patient and consecutively compared with mean T2 values using analysis of variance and Spearman's rank correlation test. Receiver operating characteristics (ROC) curves were developed to identify threshold T2 values to differentiate between the ICRS grades. RESULTS: A total of 882 ROIs were examined and graduated in ICRS score 0 (67.3%), 1 (25.2%), 2 (6.2%) and the merged ICRS 3 and 4 (1.0%). T2 values increased with increasing grade of cartilage damage with a statistically significant positive correlation between T2 values and ICRS scores. A T2 value threshold of 47.6 ms was identified to differentiate between ICRS score 0 (normal) and all other grades (ROC curve analysis). CONCLUSION: T2 mapping might provide a diagnostic tool for the detection of early knee-joint cartilage damage and for the non-invasive differentiation between ICRS grades by MRI in clinical practice.

Functional ankle instability as a risk factor for osteoarthritis: using T2-mapping to analyze early cartilage degeneration in the ankle joint of young athletes.

OBJECTIVE: The aim of this study was to investigate, using T2-mapping, the impact of functional instability in the ankle joint on the development of early cartilage damage. METHODS: Ethical approval for this study was provided. Thirty-six volunteers from the university sports program were divided into three groups according to their ankle status: functional ankle instability (FAI, initial ankle sprain with residual instability); ankle sprain Copers (initial sprain, without residual instability); and controls (without a history of ankle injuries). Quantitative T2-mapping magnetic resonance imaging (MRI) was performed at the beginning ('early-unloading') and at the end ('late-unloading') of the MR-examination, with a mean time span of 27 min. Zonal region-of-interest T2-mapping was performed on the talar and tibial cartilage in the deep and superficial layers. The inter-group comparisons of T2-values were analyzed using paired and unpaired t-tests. Statistical analysis of variance was performed. RESULTS: T2-values showed significant to highly significant differences in 11 of 12 regions throughout the groups. In early-unloading, the FAI-group showed a significant increase in quantitative T2-values in the medial, talar regions (P = 0.008, P = 0.027), whereas the Coper-group showed this enhancement in the central-lateral regions (P = 0.05). Especially the comparison of early-loading to late-unloading values revealed significantly decreasing T2-values over time laterally and significantly increasing T2-values medially in the FAI-group, which were not present in the Coper- or control-group. CONCLUSION: Functional instability causes unbalanced loading in the ankle joint, resulting in cartilage alterations as assessed by quantitative T2-mapping. This approach can visualize and localize early cartilage abnormalities, possibly enabling specific treatment options to prevent osteoarthritis in young athletes.

Whole joint MRI assessment of surgical cartilage repair of the knee: cartilage repair osteoarthritis knee score (CROAKS).

OBJECTIVE: To develop a magnetic resonance imaging (MRI) scoring system for follow-up of knee cartilage repair procedures integrating assessment of the repair site and the whole joint called Cartilage Repair OsteoArthritis Knee Score (CROAKS), and to assess its reliability. DESIGN: MRI examinations of 20 patients that had undergone matrix-associated autologous chondrocyte transplantation (MACT) of the knee 12 months before were semi-quantitatively assessed for the repair site using features of the magnetic resonance observation of cartilage repair tissue (MOCART) system and for the whole joint based on experiences with the MRI Osteoarthritis Knee Score (MOAKS) instrument. Intra- and inter-observer reliability was calculated using weighted (w) kappa statistics for plates (medial/lateral tibia, medial/lateral femur, trochlea, patella), compartments (medial tibio-femoral, lateral tibio-femoral, patello-femoral) and the whole joint. For certain features with low prevalence the overall percent agreement was calculated in addition. RESULTS: For cartilage, reliability on a plate level ranged between 0.48 (lateral femur) and 1.00 (medial femur). BML assessment showed comparable results ranging on a plate level between 0.46 and 1.00 with overall percent agreement between 83.3% and 100%. Meniscal morphology assessment ranged between 0.62 and 0.94. For repair site assessment reliability ranged from 0.41 (signal intensity inter-observer) to 1.00 (several features). Overall percent agreement was above 80% for 17 of 22 features assessed (intra- and inter-observer results combined). CONCLUSIONS: Combined scoring of the repair site and whole joint assessment for common osteoarthritis features using CROAKS, which is based on experience with two established semi-quantitative scoring tools, is feasible and may be performed with good to excellent reliability.

Fast diffusion-weighted steady state free precession imaging of in vivo knee cartilage.

Quantification of molecular diffusion with steady state free precession (SSFP) is complicated by the fact that diffusion effects accumulate over several repetition times (TR) leading to complex signal dependencies on transverse and longitudinal magnetization paths. This issue is commonly addressed by setting TR > T(2), yielding strong attenuation of all higher modes, except of the shortest ones. As a result, signal attenuation from diffusion becomes T(2) independent but signal-to-noise ratio (SNR) and sequence efficiency are remarkably poor. In this work, we present a new approach for fast in vivo steady state free precession diffusion-weighted imaging of cartilage with TR << T(2) offering a considerable increase in signal-to-noise ratio and sequence efficiency. At a first glance, prominent coupling between magnetization paths seems to complicate quantification issues in this limit, however, it is observed that diffusion effects become rather T(2) (ΔD ≈ 1/10 ΔT(2)) but not T(1) independent (ΔD ≈ 1/2 ΔT(1)) for low flip angles α ≈ 10 - 15°. As a result, fast high-resolution (0.35 × 0.35 - 0.50 × 0.50 mm(2) in-plane resolution) quantitative diffusion-weighted imaging of human articular cartilage is demonstrated at 3.0 T in a clinical setup using estimated T(1) and T(2) or a combination of measured T(1) and estimated T(2) values.

Assessment of articular cartilage repair tissue after matrix-associated autologous chondrocyte transplantation or the microfracture technique in the ankle joint using diffusion-weighted imaging at 3 Tesla.

OBJECTIVE: The objective was to compare patients after matrix-associated autologous chondrocyte transplantation (MACT) and microfracture therapy (MFX) of the talus using diffusion-weighted imaging (DWI), with morphological and clinical scoring. MATERIALS AND METHODS: Twenty patients treated with MACT or MFX (10 per group) were examined using 3 T magnetic resonance imaging (MRI) at 48 ± 21.5 and 59.6 ± 23 months after surgery, respectively. For comparability, patients from each group were matched by age, body mass index, and follow-up. American Orthopaedic Foot and Ankle Society (AOFAS) score served as clinical assessment tool pre- and postoperatively. DWI was obtained using a partially balanced, steady-state gradient echo pulse sequence, as well as the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score, based on a 2D proton density-weighted turbo spin-echo sequence and a 3D isotropic true fast imaging with steady-state precession sequence. Semi-quantitative diffusion quotients were calculated after region of interest analysis of repair tissue (RT) and healthy control cartilage, and compared among both groups. RESULTS: The mean AOFAS score improved significantly (P = 0.001) for both groups (MACT: 48.8 ± 20.4-83.6 ± 9.7; MFX: 44.3 ± 16.5-77.6 ± 13.2). No differences in the AOFAS (P = 0.327) and MOCART (P = 0.720) score were observed between MACT and MFX postoperatively. DWI distinguished between healthy cartilage and cartilage RT in the MFX group (P = 0.016), but not after MACT treatment (P = 0.105). Significant correlations were found between MOCART score and DWI index after MFX (Pearson: -0.648; P = 0.043), and between the diffusivity and longer follow-up interval in MACT group (Pearson: -0.647, P = 0.043). CONCLUSION: Whereas conventional scores reveal a similar outcome after MACT or MFX treatment in the ankle joint, DWI was able to distinguish between different RT qualities, as reported histologically for these diverse surgical procedures.

Evaluation of native hyaline cartilage and repair tissue after two cartilage repair surgery techniques with 23Na MR imaging at 7 T: initial experience.

OBJECTIVE: To compare the sodium normalized mean signal intensity (NMSI) values between patients after bone marrow stimulation (BMS) and matrix-associated autologous chondrocyte transplantation (MACT) cartilage repair procedures. METHODS: Nine BMS and nine MACT patients were included. Each BMS patient was matched with one MACT patient according to age [BMS 36.7 ± 10.7 (mean ± standard deviation) years; MACT 36.9 ± 10.0 years], postoperative interval (BMS 33.5 ± 25.3 months; MACT 33.2 ± 25.7 months), and defect location. All magnetic resonance imaging (MRI) measurements were performed on a 7 T system. Proton images served for morphological evaluation of repair tissue using the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system. Sodium NMSI values in the repair area and morphologically normal cartilage were calculated. Clinical outcome was assessed right after MRI. Analysis of covariance, t-tests, and Pearson correlation coefficients were evaluated. RESULTS: Sodium NMSI was significantly lower in BMS (P = 0.004) and MACT (P = 0.006) repair tissue, compared to reference cartilage. Sodium NMSI was not different between the reference cartilage in MACT and BMS patients (P = 0.664), however it was significantly higher in MACT than in BMS repair tissue (P = 0.028). Better clinical outcome was observed in BMS than in MACT patients. There was no difference between MOCART scores for MACT and BMS patients (P = 0.915). We did not observe any significant correlation between MOCART score and sodium repair tissue NMSI (r = -0.001; P = 0.996). CONCLUSIONS: Our results suggest higher glycosaminoglycan (GAG) content, and therefore, repair tissue of better quality in MACT than in BMS patients. Sodium imaging might be beneficial in non-invasive evaluation of cartilage repair surgery efficacy.

Evaluation of articular cartilage in patients with femoroacetabular impingement (FAI) using T2* mapping at different time points at 3.0 Tesla MRI: a feasibility study.

OBJECTIVES: To define the feasibility of utilizing T2* mapping for assessment of early cartilage degeneration prior to surgery in patients with symptomatic femoroacetabular impingement (FAI), we compared cartilage of the hip joint in patients with FAI and healthy volunteers using T2* mapping at 3.0 Tesla over time. MATERIALS AND METHODS: Twenty-two patients (13 females and 9 males; mean age 28.1 years) with clinical signs of FAI and Tönnis grade ≤ 1 on anterior-posterior x-ray and 35 healthy age-matched volunteers were examined at a 3 T MRI using a flexible body coil. T2* maps were calculated from sagittal- and coronal-oriented gradient-multi-echo sequences using six echoes (TR 125, TE 4.41/8.49/12.57/16.65/20.73/24.81, scan time 4.02 min), both measured at beginning and end of the scan (45 min time span between measurements). Region of interest analysis was manually performed on four consecutive slices for superior and anterior cartilage. Mean T2* values were compared among patients and volunteers, as well as over time using analysis of variance and Student's t-test. RESULTS: Whereas quantitative T2* values for the first measurement did not reveal significant differences between patients and volunteers, either for sagittal (p = 0.644) or coronal images (p = 0.987), at the first measurement, a highly significant difference (p ≤ 0.004) was found for both measurements with time after unloading of the joint. Over time we found decreasing mean T2* values for patients, in contrast to increasing mean T2* relaxation times in volunteers. CONCLUSION: The study proved the feasibility of utilizing T2* mapping for assessment of early cartilage degeneration in the hip joint in FAI patients at 3 Tesla to predict possible success of joint-preserving surgery. However, we suggest the time point for measuring T2* as an MR biomarker for cartilage and the changes in T2* over time to be of crucial importance for designing an MR protocol in patients with FAI.

Correlation of the Histological ICRS II Score and the 3D MOCART Score for the Analysis of Aged Osteochondral Regenerates in a Large Animal Model.

OBJECTIVE: Reliable outcome measures are essential to predict the success of cartilage repair techniques. Histology is probably the gold standard, but magnetic resonance imaging (MRI) has the potential to decrease the need for invasive histological biopsies. The 3D magnetic resonance observation of cartilage repair tissue (MOCART) score is a reliable yet elaborate tool. Moreover, literature is controversial concerning the correlation of histology and MRI. DESIGN: To test the applicability of the International Cartilage Regeneration and Joint Preservation Society (ICRS) II and MOCART 3D score for the evaluation of aged osteochondral regenerates in a large animal model, and to identify correlating histological and MRI parameters. Osteochondral defects in medial femoral condyles of n = 12 adult sheep were reconstructed with biodegradable bilayer implants. About 19.5 months postoperation, n = 10 joints were analyzed with MRI (3D MOCART score). Histological samples were analyzed using the ICRS II score; both pre- and post-training. The intraclass correlation coefficient, the inter-rater reliability, and the 95% confidence interval were calculated. Matching histological and MRI parameters were tested for correlation. RESULTS: We found a statistically significant correlation of all histological parameters. MRI parameters reflecting "overall" assessments had very strong inter-rater correlations. Statistically significant strong correlations were found for the MRI parameters defect filling, cartilage interface, bone interface, and surface. For defect overall (MRI) and overall assessment (ICRS II), we found a significant yet mild correlation. CONCLUSIONS: The ICRS II and the 3D MOCART score are applicable to aged osteochondral regenerates. Prior training on the scoring systems is essential. Select MRI and histological parameters correlate; however, the only statistically significant correlation was found for overall assessment.

Comparison of meniscal T1rho- and T2*-relaxation times in professional female volleyball players and healthy controls using 3T MRI: A pilot study.

PURPOSE: Comparison of meniscal T1rho- and T2*-relaxation times in professional female volleyball players and healthy controls to determine if relaxation times are prolonged in athletes due to compositional meniscal alterations based on extensive and repetitive joint loading. METHODS: The right knee of 20 asymptomatic professional female volleyball players and 20 female controls were examined at 3T MRI. T1rho- and T2*-measurements were performed in sagittal orientation. For quantitative measurements, two readers independently defined two consecutive central slices with the greatest area of the anterior and posterior horn of the lateral (AHLAT; PHLAT) and medial meniscus (AHMED; PHMED). Both readers repeated measurements after a six-week interval on the original MR images. Statistical analysis included intraclass correlation coefficient (ICC), Wilcoxon signed-rank-, Shapiro-Wilk- & Kolmogorov-Smirnov- and Mann-Whitney U-tests. RESULTS: Mean T1rho-relaxation times in the PHMED were significantly prolonged in professional female volleyball players when compared to controls (24.2 ± 4.0 vs 21.1 ± 2.6 ms; p < 0.005). There were no significant differences for the remaining three meniscal horns. T2*-relaxation times revealed no significant differences between athletes and controls. Prolonged T1rho-relaxation times in the PHMED of female volleyball players did not correlate with significant change in T2*-relaxation times within all meniscal subregions. Reproducibility levels were excellent in all segments (Interobserver-ICC: 0.93-0.97 and intraobserver-ICC: 0.97-0.99). CONCLUSION: T1rho-relaxation times were significantly increased in the PHMED of female volleyball players, potentially indicating a predilection to early degenerative meniscal changes. T1rho may serve as a sensitive biomarker at detecting early compositional meniscal alterations in athletes.

Detection of degenerative cartilage disease: comparison of high-resolution morphological MR and quantitative T2 mapping at 3.0 Tesla.

OBJECTIVE: The aim of the study was to investigate the association of T2 relaxation times of the knee with early degenerative cartilage changes. Furthermore the impact of unloading the knee on T2 values was evaluated. METHODS: Forty-three patients with knee pain and an ICRS (International Cartilage Repair Society) cartilage defect grade

Correlation of T2* relaxation times of the retropatellar cartilage with tibial tuberosity-trochlea groove distance in professional soccer players.

The tibial tuberosity-trochlear groove (TT-TG) distance is a radiographic measurement that is used to quantify malalignment of the patellofemoral joint (PFJ) in cross-sectional imaging. There is an ongoing debate about the impact of the TT-TG-distance on lateral patellar instability and the initiating of cartilage degeneration. In this prospective study, the association of T2* relaxation times and TT-TG distances in professional soccer players was analyzed. 36 knees of 18 professional soccer players (age: 21 ± 2.8 years) were evaluated. Participants underwent knee MRI at 3 T. For qualitative image analysis, fat-saturated 2D PD-weighted Fast Spin Echo (FSE) and T1-weighted FSE sequences were used. For quantitative analysis, T2* measurements in 3D data acquisitions were performed. In a qualitative analysis there was no structural cartilage damage and no abnormalities of the patellar and trochlea shape. The highest T2* values (26.7 ± 5.9 ms) were observed in the central compartment of the patella. The mean TT-TG distance was 10 ± 4 mm (range 3-20 mm). There was no significant correlation between TT-TG distance and T2* relaxation times in all three compartments of the retropatellar cartilage. Our study shows that so long as patellar and trochlear morphology is normal, TT-TG distance alone does not affect the tissue structure of the retropatellar cartilage in professional soccer players.

Platelet-rich plasma (PRP) as therapy for cartilage, tendon and muscle damage - German working group position statement.

PURPOSE: Platelet rich plasma (PRP) is widely used in orthopaedics, but is still heavily debated. Therefore, a survey among the German "Working Group for Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology was conducted to achieve a consensus about the current therapeutical potential of PRP. METHODS: A first survey (n = 65 experts, all orthopaedic/trauma surgeons) was conducted (n = 13 questions). Following, a second round (n = 40 experts) was conducted with 31 questions to achieve consensus in 5 categories: three most common indications, PRP application, future research areas. RESULTS: Therapeutic PRP application was regarded as useful (89%), possibly even more important in the future (90%). Most common indications were tendon pathologies (77%), osteoarthritis (OA) (68%), muscle injuries (57%) and cartilage damage (51%). Consensus was reached in 16/31 statements. The application of PRP for early knee OA (Kellgren-Lawrence grade II) was regarded as potentially useful, as well as for acute and chronic tendinopathies. For chronic lesions (cartilage, tendons), multiple injections (2-4) were seen preferable to singular injections. However, no sufficient data exists on the time interval between the injections. Standardization of PRP preparation, application, frequency, as well as determining the range of indication is strongly recommended. CONCLUSIONS: There is a need of further standardization of the PRP preparation methods, indication and application protocols for knee OA and other indications, which must be further evaluated in basic science studies and randomized controlled clinical trials. LEVEL OF EVIDENCE: Consensus of expert opinion, Level V.

Multimodal approach in the use of clinical scoring, morphological MRI and biochemical T2-mapping and diffusion-weighted imaging in their ability to assess differences between cartilage repair tissue after microfracture therapy and matrix-associated autologous chondrocyte transplantation: a pilot study.

OBJECTIVE: The aim of the present pilot study is to show initial results of a multimodal approach using clinical scoring, morphological magnetic resonance imaging (MRI) and biochemical T2-relaxation and diffusion-weighted imaging (DWI) in their ability to assess differences between cartilage repair tissue after microfracture therapy (MFX) and matrix-associated autologous chondrocyte transplantation (MACT). METHOD: Twenty patients were cross-sectionally evaluated at different post-operative intervals from 12 to 63 months after MFX and 12-59 months after MACT. The two groups were matched by age (MFX: 36.0+/-10.4 years; MACT: 35.1+/-7.7 years) and post-operative interval (MFX: 32.6+/-16.7 months; MACT: 31.7+/-18.3 months). After clinical evaluation using the Lysholm score, 3T-MRI was performed obtaining the MR observation of cartilage repair tissue (MOCART) score as well as T2-mapping and DWI for multi-parametric MRI. Quantitative T2-relaxation was achieved using a multi-echo spin-echo sequence; semi-quantitative diffusion-quotient (signal intensity without diffusion-weighting divided by signal intensity with diffusion weighting) was prepared by a partially balanced, steady-state gradient-echo pulse sequence. RESULTS: No differences in Lysholm (P=0.420) or MOCART (P=0.209) score were observed between MFX and MACT. T2-mapping showed lower T2 values after MFX compared to MACT (P=0.039). DWI distinguished between healthy cartilage and cartilage repair tissue in both procedures (MFX: P=0.001; MACT: P=0.007). Correlations were found between the Lysholm and the MOCART score (Pearson: 0.484; P=0.031), between the Lysholm score and DWI (Pearson:-0.557; P=0.011) and a trend between the Lysholm score and T2 (Person: 0.304; P=0.193). CONCLUSION: Using T2-mapping and DWI, additional information could be gained compared to clinical scoring or morphological MRI. In combination clinical, MR-morphological and MR-biochemical parameters can be seen as a promising multimodal tool in the follow-up of cartilage repair.

MR imaging of cartilage and its repair in the knee--a review.

Chondral injuries are common lesions of the knee joint, and many patients could benefit from cartilage repair. Widespread cartilage repair techniques require sophisticated noninvasive follow-up using MRI. In addition to the precise morphological assessment of this area of cartilage repair, the cartilage's biochemical constitution can be determined using biochemical MRI techniques. The combination of the clinical outcome after cartilage repair together with the morphological and biochemical description of the cartilage repair tissue as well as the surrounding cartilage can lead to an optimal follow-up evaluation. The present article on MR imaging techniques of cartilage repair focuses on morphological description and scoring using techniques from conventional 2D through advanced isotropic 3D MRI sequences. Furthermore the ultrastructure of the repair tissue and the surrounding cartilage is evaluated in-vivo by biochemical T1-delayed gadolinium enhanced MRI of cartilage (dGEMRIC), T2 relaxation, and diffusion-weighted imaging techniques.

Effects of vagus nerve stimulation on cardiovascular regulation in patients with epilepsy.

OBJECTIVE: To evaluate the impact of vagus nerve stimulation (VNS) on heart rate and blood pressure (BP) modulation in epilepsy patients. MATERIAL AND METHODS: Twenty-one epilepsy patients with VNS were tested during on (60 s) and off (5 min) phases. We monitored BP, RR intervals (RRI) and respiration. Spectral analysis was performed in low- (LF: 0.04-0.15 Hz) and high-frequency bands (HF: 0.15-0.5 Hz). For coherences above 0.5, we calculated the LF transfer function between systolic BP and RRI, and the HF transfer function gain and phase between RRI and respiration. Differences between the on and off phases were evaluated using Wilcoxon test. RESULTS: VNS did not change RRI and BP values. The LF power of BP and the LF and HF power of RRI increased significantly. There was a slight change in the RRI/BP LF gain and the RRI/respiration HF gain (ns). The HF phase between RRI and respiration decreased significantly. CONCLUSIONS: Our findings show that VNS influences both sympathetic and parasympathetic cardiovascular modulation. However, our results also show that VNS does not negatively influence autonomic cardiovascular regulation.

Comparison of T2* relaxation times of articular cartilage of the knee in elite professional football players and age-and BMI-matched amateur athletes.

OBJECTIVE: Recent investigation has underlined the potential of quantitative MR imaging to be used as a complementary tool for the diagnosis of cartilage degeneration at an early state. The presented study analyses T2* relaxation times of articular cartilage of the knee in professional athletes and compares the results to age- and BMI (Body Mass Index)-matched healthy amateur athletes. MATERIALS AND METHODS: 22 professional football players and 22 age- and BMI-matched individuals were underwent knee Magnetic Resonance Imaging (MRI) at 3T including qualitative and quantitative analysis. Qualitative analysis included e.g. meniscal tears, joint effusion and bone edema. For quantitative analysis T2* (22 ET: 4.6-53.6ms) measurements in 3D data acquisition were performed. Deep and superficial layers of 22 predefined cartilage segments were analysed. All data sets were postprocessed using a dedicated software tool. Statistical analysis included Student t-test, confidence intervals and a random effects model. RESULTS: In both groups, T2* relaxation times were significantly higher in the superficial compared to the deep layers (p<0.001). Professional athletes had significantly higher relaxation times in eight superficial and three deep cartilage layers in the predefined cartilage segments (p<0.05). Highly significant differences were found in the weight-bearing segments of the lateral superficial femoral condyle (p<0.001). CONCLUSION: Elevated T2* values in cartilage layers of professional football players compared to amateur athletes were noted. The effects seem to predominate in superficial cartilage layers.