[Treatment course in endoprosthetic knee replacement--a systematic insurance cost calculation exemplified by a concrete example]. / Der Behandlungsablauf bei endoprothetischem Kniegelenkersatz--eine systematische Kostenträgerrechnung am konkreten Beispiel.

In view of the planned introduction of the DRG system in Germany, this paper gives the reader a guideline on how to analyse costs and productivity of medical procedures. Total knee replacement was chosen because it is one of the standard operations in orthopedic surgery with existing special calculations for this type of operation. By using the example of a total knee replacement, productivity phases are used and their costs are estimated. With these phases the clinician is able to analyse the efficiency of his department and a benchmarking is possible. Nevertheless, we should not forget that although cost reduction in hospitals is essential the patients' health is the main aim of treatment.

Subtrochanteric stress fracture of the femur following total knee arthroplasty.

This study reports the first case of a subtrochanteric stress fracture of the femur after total knee arthroplasty. A 61-year-old obese woman was treated by right total knee arthroplasty for osteoarthrosis. Four months after the surgery and 1 month after full weight bearing, she complained of tenderness in the right groin and proximal thigh. There was no history of trauma. Radiographs of the right hip and of the right proximal femur were interpreted as unremarkable, and nonsteroid anti-inflammatory drugs were administered. Three months later, she had a sudden onset of increased pain with instability and giving way of the right leg. Radiographs revealed a subtrochanteric transverse fracture of the right femur. Histologic workup of the bone and tissue specimen taken at open reduction, as well as the laboratory data were consistent with the radiologic and clinical diagnosis of a stress fracture. It is most likely that a decrease in the tension band effect of the iliotibial tract in combination with coxa vara and changes in static and dynamic forces of the femur and an increased level of activity after a period of relative inactivity secondary to the knee arthroplasty are responsible for this very uncommon fracture type.