Möglichkeiten und Perspektiven zum Einsatz der künstlichen Intelligenz in der Sportorthopädie

peer reviewedIn many scientific fields, the growth of knowledge is progressing extremely rapidly. However, this also requires new techniques to identify relevant data from the mass of evidence. Scientific evidence can help improve therapeutic decision-making as well as injury prevention and optimize return to sport activity. Artificial intelligence (AI) enables these processes to be significantly assisted. As these new concepts are known to very few orthopedic surgeons and sports physicians, this article will explain basic concepts of AI, clarify differences with classical statistics, and describe its potential applications in sports orthopedics

Regions at Risk in the Knee Joint of Young Professional Soccer Players: Longitudinal Evaluation of Early Cartilage Degeneration by Quantitative T2 Mapping in 3 T MRI

Purpose The study aims to detect regions at risk for (pre-)osteoarthritis in the tibiofemoral joint of young professional soccer players by evaluating cartilage composition by T2 mapping in a 3 T magnetic resonance imaging setting. Methods In this longitudinal study, 20 professional adolescent soccer players were included. Tibiofemoral cartilage was assessed by quantitative T2 mapping and T2 values were evaluated by regions of interest analysis. Statistical evaluation, using Wilcoxon signed-rank tests, was performed to compare global T2 values and subregional T2 values between a baseline and a follow-up investigation 4.3 years later. Based on the average of playing time (15 years) we divided the cohort in 2 groups and differences were evaluated. Results When comparing baseline and follow-up, our findings showed statistically significant increases of the global medial tibial and femoral T2 values. The most noticeable results of the subregional T2 analysis were statistically significant increases in the medial posterior zones (deep femoral 36.1 vs. 39.5, P = 0.001; superficial femoral 57.0 vs. 62.4, P = 0.034; deep tibial 28.3 vs. 34.1, P = 0.009; superficial tibial 43.2 vs. 55.3, P = 0.002). Conclusion The elevation of T2 values in the medial, especially medial posterior, compartment of the knee joint indicates that these regions are at risk for early cartilage degeneration already at the time of adolescence. The findings can help individualize and optimize training concepts and to be aware of the chronic stress on these vulnerable areas. Prevention programs should be established in young players to avoid further cartilage damage

Transplantation of Chemically Processed Decellularized Meniscal Allografts: A Pilot Sheep Study

Objective The aim of this study was to evaluate the chondroprotective effect of chemically decellularized meniscal allografts transplanted into the knee joints of adult merino sheep. Methods Lateral sheep meniscal allografts were chemically processed by a multistep method to yield acellular, sterile grafts. The grafts were transplanted into the knee joints of sheep that were treated by lateral meniscectomy. Joints treated by meniscectomy only and untreated joints served as controls. The joints were analyzed morphologically 6 and 26 weeks after surgery by the macroscopical and histological OARSI (Osteoarthritis Research Society International) score. Additionally, the meniscal grafts were biomechanically tested by cyclic indentation. Results Lateral meniscectomy was associated with significant degenerative changes of the articular cartilage of the lateral joint compartment. Transplanted lateral meniscal allografts retained their integrity during the observation period without inducing significant synovitis or foreign body reactions. Cellular repopulation of the grafts was only present on the surface and the periphery of the lateral meniscus, but was still completely lacking in the center of the grafts at week 26. Transplantation of processed meniscal allografts could not prevent degenerative changes of the articular cartilage in the lateral joint compartment. Compared with healthy menisci, the processed grafts were characterized by a significantly reduced dynamic modulus, which did not improve during the observation period of 26 weeks in vivo. Conclusion Chemically decellularized meniscal allografts proved their biocompatibility and durability without inducing immunogenic reactions. However, insufficient recellularization and inferior stiffness of the grafts hampered chondroprotective effects on the articular cartilage

Quantitative T2 Mapping Shows Increased Degeneration in Adjacent Intervertebral Discs Following Kyphoplasty

Objective A minimally invasive treatment of osteoporotic and nonosteoporotic thoracic and lumbar spine fractures is cement augmentation (kyphoplasty). Little is known about the impact on adjacent intervertebral discs. A quantitative magnetic resonance imaging (MRI) approach in addition to morphological MRI is desirable to evaluate changes in the intervertebral disc. Our study aims to evaluate the feasibility of T2 mapping for the detection of subtle changes in the intervertebral discs in spines after kyphoplasty. Design Intervertebral discs were assessed by quantitative MRI (3.0 T) using T2 relaxation time mapping. Region of interest (ROI; 6 per disc) analyses were performed. The ROIs at the anterior and posterior edges were interpreted as annulus fibrosus (AF). The 2 very inner zones were regarded as nucleus pulposus (NP) and the regions in between as intermediate transition zone. We compared T2 relaxation time values of intervertebral discs adjacent to the vertebrae after kyphoplasty with those nonadjacent to vertebrae after kyphoplasty, especially in the NP. Results The analysis of the ROIs showed that the intervertebral discs of the adjacent vertebral segments are associated with reduced T2 values compared to those that are nonadjacent to the affected vertebrae. Conclusion This study is to our knowledge the first investigation of intervertebral discs after kyphoplasty by quantitative MRI. Quantitative T2 mapping shows increased degeneration in adjacent intervertebral discs following kyphoplasty. Besides its contribution to a broader knowledge of postoperative changes after kyphoplasty, our findings may help to improve differentiation between healthy and degenerated intervertebral discs using these techniques

Cinematic rendering in rheumatic diseases—Photorealistic depiction of pathologies improves disease understanding for patients

Background Patient education is crucial for successful chronic disease management. Current education material for rheumatic patients however rarely includes images of disease pathologies, limiting patients’ disease understanding. Cinematic rendering (CR) is a new tool that allows segmentation of standard medical images (DICOMs) into pictures that illustrate disease pathologies in a photorealistic way. Thus CR has the potential to simplify and improve the explanation of disease pathologies, disease activity and disease consequences and could therefore be a valuable tool to effectively educate and inform patients about their rheumatic and musculoskeletal disease (RMD). Objectives To examine the feasibility of creating photorealistic images using CR from RMD patients depicting typical rheumatic disease pathologies and, in a second step to investigate the patient-perceived educational potential of these photorealistic images in clinical routine. Methods We selected conventional, high-resolution (HR) and positron emission tomography (PET) computed tomography (CT) images of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), axial spondyloarthritis (axSpA), and giant cell arteritis (GCA) that showed typical respective disease pathologies. These images were segmented using CR technique. In a prospective study, physicians used CR-enhanced and conventional original images to explain the depicted pathognomonic pathologies to patients with the respective rheumatic disease. Patients were then asked to complete a questionnaire evaluating the perceived usefulness of being presented with CR-enhanced images to better understand their underlying disease. Results CR images were successfully generated from above mentioned CT methods. Pathologies such as bone erosions, bony spurs, bone loss, ankylosis, and PET-based inflammation could be visualized in photorealistic detail. A total of 79 patients (61% females) with rheumatic diseases (RA 29%, PsA 29%, axSpA 24%, GCA 18%) were interviewed and answered the quantitative questionnaire. Mean age was 55.4 ± 12.6 years. Irrespective of disease, all patients agreed or highly agreed that CR-based images help to improve disease understanding, should be shown at disease onset, provide a rationale to regularly take medication and would like to have access to their own CR-enhanced images. Conclusion Conventional disease images can successfully be turned into photorealistic disease depictions using CR. Patients perceived CR images as a valuable addition to current patient education, enabling personalized disease education and potentially increased medication adherence

Stimulation of the soluble guanylate cyclase (sGC) inhibits fibrosis by blocking non-canonical TGFβ signalling

Objectives We have previously described the antifibrotic role of the soluble guanylate cyclase (sGC). The mode of action, however, remained elusive. In the present study, we describe a novel link between sGC signalling and transforming growth factor β (TGFβ) signalling that mediates the antifibrotic effects of the sGC. Methods Human fibroblasts and murine sGC knockout fibroblasts were treated with the sGC stimulator BAY 41-2272 or the stable cyclic guanosine monophosphate (cGMP) analogue 8-Bromo-cGMP and stimulated with TGFβ. sGC knockout fibroblasts were isolated from sGCIfl/fl mice, and recombination was induced by Cre-adenovirus. In vivo, we studied the antifibrotic effects of BAY 41-2272 in mice overexpressing a constitutively active TGF-β1 receptor. Results sGC stimulation inhibited TGFβ-dependent fibroblast activation and collagen release. sGC knockout fibroblasts confirmed that the sGC is essential for the antifibrotic effects of BAY 41-2272. Furthermore, 8-Bromo-cGMP reduced TGFβ-dependent collagen release. While nuclear p-SMAD2 and 3 levels, SMAD reporter activity and transcription of classical TGFβ target genes remained unchanged, sGC stimulation blocked the phosphorylation of ERK. In vivo, sGC stimulation inhibited TGFβ-driven dermal fibrosis but did not change p-SMAD2 and 3 levels and TGFβ target gene expression, confirming that non-canonical TGFβ pathways mediate the antifibrotic sGC activity. Conclusions We elucidated the antifibrotic mode of action of the sGC that increases cGMP levels, blocks non-canonical TGFβ signalling and inhibits experimental fibrosis. Since sGC stimulators have shown excellent efficacy and tolerability in phase 3 clinical trials for pulmonary arterial hypertension, they may be further developed for the simultaneous treatment of fibrosis and vascular disease in systemic sclerosis

Diagnosis of left ventricular noncompaction cardiomypathy by magnetic resonance tomography

Die kardiale Magnetresonanztomographie spielt in der Diagnostik der linksventrikulären „noncompaction“ Kardiomyopathie (LVNC) bislang eine eher untergeordnete Rolle. Definierende Kriterien wurden hauptsächlich für echokardiographische Untersuchungen formuliert. Die meisten MRT-Studien zu LVNC konzentrierten sich auf die Detektion von Trabekularisierung an wenigen Stellen und weniger auf die hier durchgeführte ausführliche Messung kompaktierter und nicht-kompaktierter Anteile der Myokardmasse mittels MRT. Diese Betrachtungsweise wurde bislang nur von einer Forschungsgruppe beschrieben. Die vorliegende Arbeit hat die Anwendbarkeit der kardialen Magnetresonanztomographie in der Diagnostik der linksventrikulären „noncompaction“ Kardiomyopathie untersucht und gezeigt, dass sie zur Abgrenzung gegenüber anderen Herzerkrankungen eine diagnostische Erweiterung ist. Hierzu wurden fünf Gruppen einer kardialen MRT-Untersuchung mit einem 1,5 T Gerät unterzogen und die Bilder mit einer analytischen Software (CAAS MRI 3.0, PIE Medical Imaging) und mithilfe des 17-Segment Modells der American Heart Association (AHA) ausgewertet. Zwölf „noncompaction“-Patienten und acht Borderline-Patienten, die echokardiographisch einen nicht-signifikant ausgeprägten Grad von LVNC aufwiesen, und jeweils aus Familien mit familiärer Häufung der LVNC stammten, sowie zehn Patienten mit hypertropher Kardiomyopathie (HCM), elf Patienten mit dilatativer Kardiomyopathie (DCM) und 24 Probanden, die keine Herzerkrankung hatten, wurden untersucht. Die Ergebnisse zeigten in wichtigen Aspekten (hoch-)signifikant unterschiedliche Ergebnisse im Vergleich zwischen „noncompaction“-Patienten mit Borderline- Patienten, HCM- Patienten, DCM-Patienten und Probanden. Der Index der linksventrikulären Gesamtmyokardmasse lässt eine eindeutige Abgrenzung der LVNC-Gruppe im Vergleich mit Probanden, Borderline- und DCM-Patienten zu. Eine Differenzierung zu HCM-Patienten war mit diesem Parameter nicht möglich. Das alleinige Auftreten von erhöhten linksventrikulären Muskelmasse-Indizes kann einen Hinweis auf das Vorliegen einer „noncompaction“ Kardiomyopathie geben, kann jedoch auch bei der HCM auftreten. Der Index der nicht-kompaktierten Myokardmasse hingegen ist bei Erhöhung spezifisch für die „noncompaction“ Kardiomyopathie. Der nicht-kompaktierte Myokardmasse-Index detektiert bei einem Wert von 15 g/m² die LVNC mit einer Sensitivität von 91 % und einer Spezifität von 100 %. Hier zeigt sich ein weiteres wertvolles Kriterium für die Diagnostik der „noncompaction“ Kardiomyopathie. Mit der hier verwendeten Mess-Methode kann bei einem prozentualen Anteil trabekularisierter Myokardmasse an der linksventrikulären Gesamtmyokardmasse von über 25 % die Diagnose „noncompaction“ Kardiomyopathie sicher gestellt werden. Zwischen 20 % und 25 % trabekularisierter Myokardmasse an der Gesamtmyokardmasse muss differentialdiagnostisch eine leicht ausgeprägte „noncompaction“ Kardiomyopathie (Borderline) oder eine hypertrophe Kardiomyopathie in Betracht gezogen werden. Bei einem Wert von unter 20 % Anteil trabekularisierter Myokardmasse an der Gesamtmyokardmasse ist die Diagnose einer „noncompaction“ Kardiomyopathie sehr unwahrscheinlich. Eindeutiges Kriterium für die Diagnose der „noncompaction“ Kardiomyopathie ist die Verteilung der nicht-kompaktierten Areale auf die 17 Segmente nach der Einteilung der AHA in Verbindung mit der Betrachtung der Muskelmasse-Indizes und des Anteils der nicht-kompaktierten Myokardmasse an der linksventrikulären Gesamtmyokardmasse. Die Patienten mit der Diagnose „noncompaction“ Kardiomyopathie wiesen im Durchschnitt gegenüber allen Gruppen eine mindestens doppelt so hohe Anzahl an trabekularisierten Segmenten auf. In der NCM-Gruppe gab es kein Segment, das nie betroffen war. Jedes der 17 Segmente war bei mindestens einem der Patienten trabekularisiert. Das Auftretren von Trabekularisierung in den basalen inferioren, basalen inferolateralen und basalen anterolateralen Segmente (Segmente 4, 5 und 6 der AHA) ist diagnostisch wegweisend für LVNC. In den anderen Segmenten weist erst das Verhältnis von trabekularisiertem zu kompaktiertem Myokard von mehr als 3:1 eine gute Sensitivität bei gleichzeitig hoher Spezifität auf. Bei Erfüllung von mindestens zwei der vier Hauptkriterien 1\. prozentualer Anteil der trabekularisierten Myokardmasse an der Gesamtmyokardmasse > 25 %, 2\. Myokardmasseindex der trabekularisierten Myokardmasse > 15 g/m², 3\. Trabekularisierung in den Segmenten 4, 5 und 6 und 4\. Verhältnis trabekularisiertes Myokard zu kompaktiertem Myokard > 3:1 in mindestens einem der anderen Segmente zeigt sich die höchste Sensitivität bei gleichzeitig hoher Spezifität. Das Auftreten von Late Enhancement kann nach Auswertung der vorliegenden Untersuchung als Ausschlusskriterium der „noncompaction“ Kardiomyopathie vorgeschlagen werden, was die Spezifität dann auf optimale Werte zu erhöhen hilft. Die Überprüfung der Intraobserver-Reproduzierbarkeit ergab eine durchschnittliche Übereinstimmung der Ergebnisse von 96,97 Prozent. Dies zeigt eine sehr niedrige Variabilität der Messungen bei Wiederholung.The cardiac magnetic resonance tomography plays a rather subordinated role in the diagnosis of left ventricular “noncompaction” cardiomyopathy (LVNC) at present. Defining criteria have mainly been formulated for echocardiographic examinations. Most of the studies dealing with LVNC focus on the detection of trabeculation on a few parts rather than on a detailed measurement of the compacted or non-compacted areas of the myocardial mass by MRI as performed here. This approach was described by only one research group before. This study has examined the applicability of cardiac MRI in the diagnosis of left ventricular “noncompaction” cardiomyopathy and has shown that it is a diagnostic increment to distinguish LVNC from other pathologies of the heart. Five groups underwent a cardiac MR-examination in an 1,5 T MR tomograph. The images were evaluated with an analytic software (CAAS MRI 3.0, PIE Medical Imaging) and with the aid of the 17 segments model of the American Heart Association (AHA). Twelve “noncompaction” patients, eight borderline patients who had echocardiographically a non-significant grade of LVNC, ten patients with hypertrophic cardiomyopathy (HCM), eleven patients with dilatative cardiomyopathy (DCM) und 24 probands who had no cardiac disease underwent the examination. The results show (highly) significant results in important aspects of the comparison between “noncompaction” patients and borderline patients, HCM patients, DCM patients and probands. The index of the left ventricular myocardial mass allows a clear differentiation of the LVNC group towards the probands, the borderline and the DCM patients. The discrimination towards the HCM patients with this parameter was not possible. The only occurrence of increased left ventricular myocardial mass indices may give a hint on the existence of a “noncompaction” cardiomyopathy but it can also appear in HCM. Whereas the elevation of the index of noncompacted myocardial mass is specific for “noncompaction” cardiomyopathy. The noncompacted myocardial mass index detects LVNC at a value of 15 g/m² with a sensitivity of 91 % and a specificity of 100 %. This indicates a valuable criterion for the diagnosis of “noncompaction” cardiomyopathy. With the method of measurement that has been used here, “noncompaction” cardiomyopathy can be diagnosed securely at a percentage of the trabeculated myocardial mass of left ventricular myocardial mass of over 25. Between 20 and 25 percent trabeculated myocardial mass of the total myocardial mass, the differential diagnosis may be a light distinction of “noncompaction” cardiomyopathy (borderline) or hypertrophic cardiomyopathy. If the percentage of the trabeculated myocardial mass of the total myocardial mass is below 20, the diagnosis “noncompaction” cardiomyopathy is very unlikely. A clear criterion for the diagnosis of “noncompaction” cardiomyopathy is the distribution/dispersal of noncompacted areas to the 17 segments of the AHA in connection with the consideration of the myocardial indices and the percentage of the noncompacted myocardial mass of the left ventricular total myocardial mass. The patients with the diagnosis “noncompaction” cardiomyopathy had at least doubled numbers of noncompacted segments compared to all other groups. In the “noncompaction” group none of the segments was never trabeculated. Each of the 17 segments was trabeculated in at least one patient. The occurrence of trabeculation in the basal inferior, basal inferolateral and the basal anterolateral segments (segments 4, 5 and 6 of the AHA) is indicating the diagnosis of LVNC. In all other segments the proportion of trabeculated to compacted myocardium of more than 3:1 is necessary to give a high sensitivity with a high specificity at the same time. In case of completion of at least two of the four main criteria 1\. percentage of trabeculated myocardial mass of complete myocardial mass > 25 % 2\. myocardial index of trabeculated myocardial mass > 15 g/m² 3\. trabeculation of the segments 4, 5 and 6 and 4\. proportion of trabeculated to compacted myocardium > 3:1 in at least one of the other segments the sensitivity reaches the highest values with a high sensitivity at the same time. The occurrence of Late Enhancement can be proposed as an exclusion criterion after evaluation of the results of this study. This helps to optimize the sensitivity and the specificity. The verification of the intraobserver reproducibility proved a congruence of the results of 96,97 percent on average. This shows a very low variability of the measurements when repeated

Using Cartilage MRI T2-Mapping to Analyze Early Cartilage Degeneration in the Knee Joint of Young Professional Soccer Players

Objective To evaluate and characterize the appearance of articular cartilage in the tibiofemoral joint of young professional soccer players using T2-relaxation time evaluation on magnetic resonance imaging (MRI). Design In this study, we included 57 male adolescents from the youth academy of a professional soccer team. The MRI scans were acquired of the knee joint of the supporting leg. An “early unloading” (minute 0) and “late unloading” (minute 28) T2-sequence was included in the set of images. Quantitative T2-analysis was performed in the femorotibial joint cartilage in 4 slices with each 10 regions of interest (ROIs). Statistical evaluation, using Wilcoxon signed-rank tests, was primarily performed to compare the T2 values of the “early unloading” and “late unloading.” Results When comparing “early unloading” with “late unloading,” our findings showed a significant increase of T2-relaxation times in the weightbearing femoral cartilage of the medial (P < 0.001) and lateral (P < 0.001) compartment of the knee and in the tibial cartilage of the medial compartment (P < 0.001). Conclusion In this study, alterations of the cartilage were found with a maximum in the medial condyle where the biomechanical load of the knee joint is highest, as well as where most of the chronic cartilage lesions occur. To avoid chronic damage, special focus should be laid on this region