[Knee joint injuries.]

Careful technique of examination of the knee joint allows to establish the diagnosis of the most frequent knee joint injuries already through simple clinical and radiological evaluation: Recurrent dislocation of the patella with the Apprehension sign; meniscal injuries with the test of McMurray, pain on the joint line and pain on passive hyperextension; the anterior cruciate ligament tear with Lachman's sign and the Pivot Shift test and posterior cruciate injury with the Sag sign. Further imaging techniques allow to establish a definite diagnosis, which has replaced in many cases the classical, purely diagnostic arthroscopy. Thanks to careful aspiration of the knee joint the patient can be referred with a more precise diagnosis to the traumatologist and orthopaedic surgeon. Meniscal lesions don't have to be treated as emergencies with exception of the locked knee. Equally, in presence of a fresh tear of the anterior cruciate ligament a delay of surgery for eight weeks may be beneficial, be it only to rehab and prepare the knee joint for surgery. Posterior cruciate ligament tears should only be treated by a few centers, since they demand a high degree of experience. The same accounts for the new techniques for the treatment of cartilage lesions like the mosaicplasty or the autologous chondrocyte implantation.