الفهرس 
ANATOMY OF THE KNEE JOINTOnly 14 pages are availabe for public view
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Abstract
The knee joint is one of the most commonly injured joints in the body. Because of its complex structure, the joint is subjected to numerous pathologies and due to the recent increase in various sport activities; there has been a parallel increase in sport-induced internal dearangements of the knee.
Ultrasound is emerging as a viable imaging modality in the diagnosis and assessment of the musculoskeletal system lesions especially in experienced hands.
Advantages of ultrasound include it is non-invasive, well accepted by patients, available , the ability to compare easily with the contralateral side, multi planar and dynamic evaluation , as well as its economic advantages. Unlike magnetic resonance imaging ,the patient’s exact point of clinical tenderness can be correlated with underlying anatomical structures and associated pathology.
The main strength of knee ultrasound is the assessment of para-articular disease. The specific structures best suited for ultrasound assessment include tendons, muscles and ligaments, as well as peri articular soft tissue masses. Joint effusions, synovial thickening, bursal fluid
Also there are some limitations in detecting meniscal and cruciate pathology such as:
• Inability to judge the difference in echogenicity of cruciate ligaments when they were torn.
• Inabilities to accurately discriminate a partial tear from a full thickness tear in cruciate ligaments by US.
• The obesity is a factor that limits the proper visualization of cruciate ligaments by ultrasonography. In addition it decreases the degree of knee flexion leading to a more difficult examination.
MRI has unique advantages over other imaging modalities .First; it is totally non-invasive and has no known adverse effects on the human body. Secondly, it can provide information not only on the density of tissues but also on their chemical structure. Thirdly, MRI can provide a direct three-dimensional view of the part examined. For the diagnosis of knee disorders, an understanding of the normal knee is clearly essential.
So we conclude that, the high resolution ultrasonography can be used as a preliminary diagnostic tool after clinical examination. If it shows normal pattern for menisci and cruciates, no need for further study, while if any abnormality is detected, the decision to perform more costly MR imaging or to go directly for surgical intervention will be mandatory.