injuries poisoning
Knee Extensor Mechanism Injuries
Introduction
Knee extensor mechanism injuries can involve the quadriceps tendon, patellar tendon, patella, or tibial tubercle. Surgical repair is usually required. (See also Overview of Sprains and Other Soft-Tissue Injuries .) Extension of the knee involves the quadriceps muscles, which are attached to the patella by the quadriceps tendon; the patella is connected to the tibial tubercle by the patellar tendon. Forced flexion at the knee with a contracted quadriceps muscle can damage these structures. Injuries include Quadriceps tendon tears Patellar tendon tears Patellar fractures Tibial tubercle fractures In healthy people, significant force is required to injure these structures; normal tendons are strong enough that the patella often fractures transversely before a tendon tears. However, people with certain conditions are at risk of tendon tears. These conditions include Older age Osteoarthritis (OA) None Use of certain medications (eg, fluoroquinolones, corticosteroids) Diabetes Mellitus (DM) None Obesity None Pathophysiology None Polyneuropathy None Anabolic Steroids None In these at-risk people, the injury can result from minor trauma (eg, when descending stairs). The quadriceps tendon is injured more often than the patellar tendon, particularly in older people. 