[Complex trauma of the knee joint. Diagnosis--management--therapeutic principles].

The complex nature of combined fractures and soft tissue injuries of the distal femur and proximal tibia needs special attention and specific management. Distal femoral and proximal tibial fractures in young patients are usually caused by high-energy trauma. They are complicated by a high rate of systemic and local injuries to cartilage, ligaments and skin. This small but important group with severe injuries needs a detailed treatment algorithm, because despite the treating surgeon's skill, enthusiasm and wishful thinking, these injuries frequently lead to unsatisfactory results. The combination of distal femoral fractures and proximal tibial fractures was defined as complex knee injury type 1; the combination of distal femoral fractures or proximal tibial fractures with second or third degree open or closed soft-tissue injury was defined as complex knee injury type 2; knee dislocations were defined as complex knee injury type 3. A decision-making scheme is presented specifically addressing timing and treatment modalities. Out of 116 type 1 and 2 complex knee injuries, 8 had a deep infection, in 6 cases an amputation was carried out and in 4 cases a knee arthrodesis was performed. In 81 isolated distal femoral fractures, only 4 had a deep infection, none needed amputation, and in only 1 case did a knee arthrodesis have to be performed. The average Neer Score in 90 followed-up complex knee injuries, types 1 and 2, was 76.5 +/- 13.5 compared with 82.8 +/- 10 (out of 54 isolated distal femoral fractures). Out of 37 cases with knee dislocation, 22 (60%) had an poor result according to the Lysholm Score (average Lysholm Score 60.7 +/- 28).