CORE DECOMPRESSION IN OSTEONECROSIS OF TH E KNEE - FOLLOW-UP AND THERAPY CONTROL BY MRT

Clinically suspected spontaneous osteonecrosis of the knee (Ahlback's disease) was confirmed by MR imaging and subsequent histology in 4 mal e patients with sudden onset of severe knee pain. The first typical ra diological sign for osteonecrosis - flattening of the affected femoral condyle - was seen in no case. All patients were treated surgically b y extraarticular drilling for core decompression and were delivered fr om the complained severe knee pain immediately after surgery. The heal ing process of these early osteonecroses could be confirmed by the nor malisation of bone marrow signal in MR imaging (3 to 15 months follow- up). Core decompression seems to be an effective treatment in early os teonecrosis of femoral condyles. MR imaging is the most sensitive meth od for early diagnosis of osteonecrosis and for preoperative planning as well as a helpful tool for a non-invasive postoperative follow-up.