[Treatment of Acute and Chronic Ruptures of the Extensor Mechanism of the Knee Joints].

Ruptures of the extensor mechanism of the knee joint are rare but disabling injuries. Injuries occur on the basis of degeneration or acute trauma. The understanding of anatomy and biomechanical function plays an essential role for choosing the right diagnostic methods and initiating successful treatment. Besides clinical examination ultrasound is a cost efficient primary diagnostic measure. Additional MRI can be beneficial for partial tears or chronic ruptures. Non-operative treatment is suitable for minor partial ruptures with sustained function. The most common methods for reattachment of the quadriceps and patellar tendon are either sutures placed through transpatellar drill holes or the use of suture anchors. For chronic ruptures various methods have been shown to be well accomplished. Most commonly local tendon flaps or harvested tendon transplants have shown good clinical outcomes. Early primary repair leads to mainly good functional outcomes. The results of chronic disruptions of the extensor mechanism of the knee vary widely.