La tendance est de faire des clichés en appui monopodal en légère flexion (15-20). On peut se contenter d'un profil en décubitus latéral dans la pathologie rotulienne. L'angle de flexion et la contraction quadricipital sont sujets à controverse en particulier pour la mesure de l'index rotulien et l'analyse de l'engagement rotulien. L'étude du cliché se concentre sur quatre points : Épaisseur de l'interligne, l'épaisseur de l'interligne est bien analysée sur le cliché de profil c'est pourquoi l'incidence en appui monopodal est plus intéressante. Dans les lésions anciennes du ligament croisé antérieur, on observe une translation tibiale antérieure fixée, associée à une disparition de l'espace occupé par le ménisque interne 2 (Le triangle clair postérieur) figure. Translation tibiale antérieure ou postérieure. La translation tibiale correspond à la sub-luxation du tibia par rapport au fémur. Elle est mesurée en prenant le bord postérieur du plateau tibial interne et le bord postérieur du condyle interne (celui dont la gouttière inter-trochléo-condylienne est la plus antérieure) figure.

un trait de fracture fémoral, tibial ou rotulien. La suspicion d'une fracture d'un plateau tibial ou d'un condyle fémoral doit faire pratiquer des incidences complémentaires notamment des trois quarts. La radiographie de profil, c'est l'incidence la plus intéressante dans la pathologie du genou. La fiabilité de son interprétation dépend de la qualité technique du cliché. Il faut impérativement obtenir une superposition des condyles postérieurs.

Des incidences complémentaires, telles que les trois quarts seront demandées en fonction des découvertes du bilan radiographique initial. La radiographie de face, la radiographie de face doit être en appui monopodal chaque fois que l'état du patient le permet. Jusqu'à 50 ans, cette incidence se fait à 15-20 de flexion. Après 50 ans ou si le patient a des antécédents chirurgicaux (méniscectomie, chirurgie ligamentaire, etc) l'incidence postéro-antérieure à 30 de flexion (schuss) apportera plus d'informations sur l'épaisseur du cartilage. Lors de la marche, les contraintes maximales au niveau fémoro-tibial se font à 30 de flexion, c'est pourquoi l'usure est mieux visualisée dans cette position. L'analyse première est globale analysant : la qualité de la trame osseuse (ostéoporose, etc.) ; l'épaisseur des espaces fémoro-tibiaux ; la densification des plateaux tibiaux interne ou externe. Il faut dans un deuxième temps rechercher des éléments spécifiques en fonction de la pathologie du patient. L'arthrose, la classification la plus utilisée pour l'arthrose est celle d'Ahlback 1 : stade I : remodelé ; stade ii : pincement inférieur à 50 de l'interligne ; stade iii : pincement supérieur à 50 de l'interligne. Cette classification est moins précise que la chondrométrie mais elle a le mérite d'être plus proche de la définition chirurgicale de l'arthrose qui correspond au contact os-os sur la radiographie mais également du point de vue anatomique. La présence de remodelés, de géodes sous chondrales, d'ostéophytes sont des éléments dégénératifs accompagnant le pincement de l'interligne, ce dernier restant toutefois l'élément principal occipital à prendre en compte. La pathologie ligamentaire, dans un contexte d'entorse il faut rechercher : un arrachement de l'épine tibiale antérieure, équivalent d'une lésion du ligament croisé antérieur ; un arrachement de l'insertion tibiale postérieure du ligament croisé postérieur ; une fracture de segond pathognomonique de la rupture du ligament croisé antérieur.

Mri evaluation of knee cartilage - scienceDirect


Th tavernier (1 d dejour (1)Clinique de la sauvegarde, avenue ben gourion,. 309, 69261 lyon Cedex. J radiol 2001; 82:387-405. La radiographie conventionnelle du genou doit permettre de confirmer le diagnostic suspecté cliniquement. Son analyse doit être systématique recherchant et mesurant certains paramètres. L'examen clinique oriente l'analyse mais il ne faut pas oublier de regarder l'ensemble des paramètres. Ce n'est qu'après ce bilan ortopedi qu'un examen complémentaire de type arthrographie, scanner, irm, scintigraphie sera éventuellement demandé. La prescription des incidences, qu'elle soit dans le cadre de l'urgence ou dans le cadre d'une pathologie chronique, ne doit guère être différente.

Small fissure in medial pattellar facet in mri, knee


In (b an additional full-thickness shouldered cartilage defect ( short arrow ) can be seen at the median patellar ridge. Axial image reveals a tiny blister-like increased signal ( arrow ) at the central aspect of the trochlear cartilage. Fibrocartilage formation, cartilage degeneration, and/or chondrocalcinosis are the result of subacute/chronic cartilage injury, as the cartilaginous tissue attempts to self-heal by fibrosis or mineralization. Mr imaging shows focal or diffuse areas of low signal intensity within the articular cartilage (. It is often difficult to differentiate fibrocartilage from chondrocalcinosis although the latter tends to be more focal and punctate and may additionally show blooming artifact on gradient echo images (. Correlation with plain films may assist in identifying the calcifications, although the lesions are often not visible, due to the low sensitivity and poor soft tissue contrast of conventional radiographs. Large areas of chondrocalcinosis may mimic incomplete discoid meniscus or vacuum in the joint (. 4: Multiple patellar cartilage abnormalities.

medial patellar facet fissure
Articular Cartilage damage, chondral, knee

Remembering and incorporating these ever-changing grading systems is a pijn challenging task for both radiologists and referring physicians. In addition, on mr imaging, a number of lesions of varying severity may be identified, the interobserver variability tends to increase with complicated scoring systems, and a particular scoring system may not be efficient in classifying all such lesions. It is, therefore, better to describe the lesions in each compartment of a joint using accurate terminology rather than trying to fit all lesions into a particular scoring system. The terminology used in common clinical practice for describing cartilage lesions is illustrated in the following paragraphs. Table 1: The International Cartilage repair Society (icrs) classification. Signal Heterogeneity, on mr imaging, signal heterogeneity may be caused by chondromalacia, fibrocartilage formation, cartilage degeneration, or mineralization. In most circumstances, chondromalacia (blistering or softening) is the earliest stage of cartilage injury; although it may be present in the cartilage either focally or diffusely in combination with higher grades of injury.

The lesion usually involves the deeper layers of the cartilage and is likely related to fluid imbibition from a not-so-well seen surface fissure. The name derives from soft malacic feeling on arthroscopic probing. Mr imaging may show focal area(s) of increased fluid-like t2 signal intensity in the deeper layers of the cartilage, with or without associated cervicocraniale focal cartilage swelling. It can be differentiated from fissure and defect from the fact that the overlying lamina splendens hypointensity remains preserved. More commonly, the chondromalacic cartilage features diffusely increased signal with loss of the normally observed gradual deep to superficial signal alteration as described above (. Axial images from different cases show diffuse hyperintensity ( long arrows ) of the lateral patellar facet cartilage (faint. A, prominent in, b which is indicative of chondromalacia.

Osteoarthritis (OA) of the

Cartilage injury is often a part of osteochondral lesions (OCLs). Ocls refer to one or two lesions on either joint surface, which have resulted from trauma, osteochondritis dissecans (ocd or insufficiency fracture. More than two to three lesions are generally clubbed together as part of osteoarthrosis. Mr imaging is the method of choice for the evaluation of both ocls and intrasubstance lesions. A number of terms have been used for describing cartilage lesions on mr imaging, and multiple grading schemes have been proposed. Some of these include the outerbridge Classification (1961 the Osteoarthritis Cartilage histopathology Grading and Staging (oarsi, 2006 the International warmtecompressen Cartilage repair Society (icrs) Classification (. Table 1 and the Whole Organ mr imaging Score muizengif (worms).

medial patellar facet fissure
What is Chondromalacia of the medial facet of the patella

Disorders of the, patellofemoral, joint Chapter

The latter, however, is not very resilient in dealing with stresses as compared to the native hyaline cartilage. Full-thickness cartilage loss commonly results in stress changes in the underlying bone, causing pain and decreased range of motion in the affected joint. On mr imaging, the normal five-layered configuration of hyaline cartilage is rarely visible, except in areas where it is thickest, for example, in patella. It is also only possible if high-resolution techniques combined with joint-specific coils and high-field strength (3 T) scanners are employed. On conventional (proton density-weighted pdw and fat-suppressed pdw fsPDW) imaging, the articular cartilage usually features a trilaminar configuration, composed pijn of a low-signal deep layer (tidemark and radial zone a thicker intermediate to hyperintense middle layer (oblique and horizontal fibers and a thin low-signal surface layer. In general, there is a gradual increase in signal from the bone surface to the articular surface. Additionally, the thickness of different layers of the cartilage vary for different surfaces of the articular bony margins (e.g., the radial layer is thicker in the weight-bearing central aspect of the tibia, and the transitional layer is thicker in the peripheral aspect) (.


Coronal images (a, b) of the knee demonstrate normal articular cartilage olie of the femoral condyles ( long arrows ) and tibial plateau ( short arrows featuring homogeneous thickness and a gradual increase in signal from the bone surface to the articular surface. The hyaline cartilage is a thin layer of soft tissue, wrapped around complex intra-articular anatomical structures. It is composed of 70 water, 20 collagen, and 510 proteoglycans and is very hypocellular since it is only composed of about 4 chondrocytes by wet weight. From superficial (near the joint fluid) to deep (near the subchondral bone the cartilage is composed of (1) the lamina splendens, which is a thin hypointense protective layer; (2) a superficial layer of horizontal collagen fibers, which provide resistance against shear stress; (3) an intermediate/transitional. The cartilage is subject to repetitive forces throughout life, and a normal adult loses 1 to 3 of articular cartilage thickness per year after 30 years of age, a process, which further worsens with the onset of osteoarthrosis or secondary insults from acute trauma, infection. In general, arthritis-related cartilage defects show irregular and obtuse margins due to repetitive wear and tear whereas acute trauma-related defects are usually focal, isolated and demonstrate well-defined shouldered margins. Cartilage damage progresses from chondromalacia (softening) to chondrosis (fissures, defects, flaps, delamination, and denudation on one side of the joint) and osteoarthrosis (cartilage defects or loss on both sides of the joint). Cartilage injuries are usually repaired by chondrocytes, which usually form fibrocartilage.

Articular Cartilage defects of Knee

Cartilage, the articular surfaces of synovial joints are covered by hyaline cartilage, which protects the underlying subchondral bones by distributing loads and absorbing shock, maintains low-contact stresses, reduces friction and enables smooth motion of the articulating osseous structures. Damage to the hyaline cartilage usually results from everyday weight-bearing forces or sport activities and might be worsened with additional destabilizing pathology, such as tears (and, thus, subsequent loss of the supportive function) of menisci or labrum. Mr imaging is the method kruidvat of choice to identify articular cartilage injuries and evaluate the post-operative reconstitution of cartilage repair tissue. Although various experimental techniques, such as T2 mapping, post-contrast T1 mapping, T1 rho imaging, glycosaminoglycan chemical exchange saturation transfer imaging (gag cest and sodium mr imaging, are becoming feasible for the assessment of cartilage tissue architecture, conventional morphologic mr imaging remains the mainstay for the. This chapter describes the structural anatomy of the articular cartilage, along with the respective normal and abnormal imaging appearances and delineates various grading systems and guidelines used in clinical practice for the imaging definitions of cartilage injury (chondrosis). In addition, surgical techniques for cartilage reconstitution are briefly discussed, and instructions are provided for filling in the structured template for the mr imaging description of repaired cartilage. 1: Normal articular cartilage.

Medial patellar facet fissure
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