A healthy young athlete is sitting at the edge of the table with knee at 90 degree flexion. He fully extends it. What will happen ?
Movement of tibial tuberosity towards lateral border of patella Photographic manual of regional ohopaedic and neurological tests By Joseph J.Cipriano 4/e p374] Modified Helfet test * While the patient is sitting on the edge of a table with the knee flexed 900 , instruct him or her to extend the knee. * If knee mechanics are within normal limits, the tibial tuberosity can be seen in line with the midline of the patella in full flexion; during extension, the tibia rotates and the tibial tubercle moves into line with the lateral border of the patella. gastrointestinal, cutaneous, musculoskeletal, pulmonary, and renal systems through progressive interstitial fibrosis. Small aerioles in the aforementioned systems show obliteration caused by intimal hyperplasia accompanied by progressive interstitial fibrosis. * In the skin, the changes begin in the fingers and hands and consist of sclerotic atrophy, which is characterized by increased dermal collagen, epidermal atrophy, and loss of skin adnexal structures. Two antinuclear antibodies are unique to systemic sclerosis. * One is Scl-70, which is found in diffuse progressive systemic sclerosis, and the other is an anticentromere antibody found in the CREST syndrome, a variant of progressive systemic sclerosis. * The CREST syndrome is characterized by calcinosis, Raynaud's syndrome (episodic ischemia of digits), esophageal dysmotility, sclerodactyly, and telangiectasia. Pulmonary hypeension and primary biliary cirrhosis are common in the CREST syndrome, but the kidneys are usually spared. * In contrast to the histologic findings with systemic sclerosis, a conjunctival biopsy that reveals noncaseating granulomas is suggestive of sarcoidosis; * Failure of the tibia to rotate during extension indicates a meniscal lesion or cruciate ligament involvement. Mechanism during flexion and extension of knee joint: The flexion and extension movements at the knee joint are invariably accompanied by rotations or conjunct rotation. * Rotation during standing position (i.e. when the foot is firmly placed on the ground) When the leg is extended, medial rotation of the femur occurs during the last 30 degrees of extension, and When the leg is flexed, lateral rotation of the femur occurs during the initial stages of flexion. * Rotation in Sitting position (i.e. when the foot is off the ground) In sitting position during extension and flexion of the knee joint, the tibia rotates instead of femur. During extension, the tibia rotates laterally to lock and stabilize the knee.During flexion the tibia rotates medially to Pain sensitive Pain Insensitive Scalp Pia-arachnoid Periostium Pial veins Dural senuses Brain Parenchyma Middle meaningeal aery Ventricular ependyma Falx cereberi Choroid plexus Proximal segments of the large pial aeries unlock the knee
Movement of tibial tuberiosity towards centre of the patella
Movement of tibial tuberiosity towards lateral border of patella
Movement of tibial tuberiosity towards medial border of patella
No change in position