[Diagnostic arthroscopy in injuries of the knee joint].

Diagnostic arthroscopy is indicated, if other methods of diagnosis have reached their limits. It has become indispensable to proper assessment of injuries of the menisci, cartilage, synovial folds, and plicae and for suspicion of isolated cruciate knee ligament rupture. The practicability or impracticability of an arthroscopic operation in a given case, of course, has bearings upon indication for diagnostic arthroscopy. Patients are usually examined in general anaesthesia, with the joint filled with liquid, using a 30-degree widle-angle lens and a video system. Probing of intra-articular structures is absolutely necessary. The following two specific groups of indications have gained particular importance in knee injuries: Acute arthroscopy is imperative in any case of hemarthrosis with unknown aetiology (ligament injuries were found in 67 per cent of these patients), and it is the diagnostic and therapeutic procedure of choice in acute locking of the knee. Diagnostic arthroscopy should be followed by re-arthroscopy, if the further clinical course cannot be explained by the findings already recorded or in case of new symptoms or additional symptoms in the wake of arthroscopic operation or if major symptoms persist. In the latter case, re-arthroscopy should be performed not later than four to six months from first treatment. Re-arthroscopy revealed a need for another arthroscopic operation after earlier diagnostic arthroscopy in 48 per cent of all cases and after previous arthroscopic operation in 63 per cent.