[Possibilities of biochemical differentiation of reactive effusions of the knee joint]

1. Differentiation of reaction effusions: Posttraumatic reaction effusions (fresh meniscus or capsular ligament lesion) displayed a greatly enhanced alkaline phosphatase activity, whereas postoperative reaction effusions that were poor and rich in cells had a comparatively high C3c value relative to the total amount of protein. In punctates from patients with patellar chondropathy and primary synovial reaction (no trauma, no postoperative condition) the lowest parameter values of of the entire study were seen. 2. Decision help with regard to therapy: Via determination of the sensitive inflammation parameter PMN elastase (E-a1PI) it is possible to initiate cartilage-protective therapy directly in case of a cartilage lesion of mild inflammatory character (E-a1PI 300-500 ng/ml), whereas in case of severe inflammation (E-a1PI 500-1000 ng/ml) anti-inflammatory drugs should be employed in the first instance. 3. Therapy control: In the follow-up control of reaction effusions the comparison of concentrations of biochemical parameters before and after intra-articular application of drugs offers a possibility of therapy control. Since with increasing inflammatory nature and disturbance of the blood-synovia barrier the concentration of the measured biochemical parameters (with the exception of glucose) increased in the synovial fluid, successful treatment should result in an absence of such an increase in concentration (or, if at all, in an only slight measure).