[Post-traumatic osteoarthritis of the knee: special indication for navigated TKA]. / Posttraumatische Gonarthrose: Spezifische Indikation für die navigierte Knietotalendoprothese.

Different studies confirmed the increased radiological implantation accuracy for computer-assisted total knee replacements. There was no study stating a significant influence of the navigation technique for total knee arthroplasties on the early clinical outcomes. In these two case reports we try to show special indications for a navigated total knee replacement to utilize the benefits of a navigation system as efficiently as possible.Case 1 had a femoral neck fracture 3 years ago and was treated with a long femoral gamma nail. The hardware was still retained. Case 2 had a fracture of the femoral diaphysis 31 years ago and showed an extra-articular deformity in the frontal and sagittal planes. Both patients developed osteoarthritis of the ipsilateral knee and were implanted with a total knee prosthesis using a navigation system.In both cases the prosthesis components showed perfect radiological alignment. The clinical outcomes at the 3-month follow-up were very satisfying. In case 1 the femoral nail did not have to be removed, thus decreasing surgery duration by 40-60 min.In both cases, the impossibility of using a femoral intramedullary alignment rod could be compensated for by the navigation system.

[Relevance of wound drainage in total knee arthroplasty--a prospective comparative study]. / Die Bedeutung der Wunddrainage in der Knieendoprothetik--eine prospektive Vergleichsstudie.

AIM: The benefits of postoperative wound drainage in patients with total knee arthroplasty (TKA) with regards to mobilisation and wound healing were studied. We wanted to determine the efficacy of an autologous blood retransfusion system. METHOD: 150 patients with TKA were divided into three groups of 50 patients: A) three wound drainages with an autotransfusion system and suction; B) no wound drainage; C) one intraarticular wound drainage without suction. Hemoglobin values, blood transfusion requirements, blood loss, postoperative range of motion, Insall knee score and rate of complications were observed and recorded. All patients were operated without tourniquets for lower blood loss. RESULTS: In the group of patients with wound drainage and a retransfusion system the requirement of postoperative additional blood transfusion was not significantly less than in the group without wound drainage. Group A had the highest blood loss of all. The group without wound drainage had more hematomas and wound healing complications. Best results were observed within the group with one intraarticular drainage without suction. The rate of complications was not increased and the blood transfusion requirements were the lowest. CONCLUSION: This study shows that total knee replacement involving one intraarticular wound drainage without suction attains the best results.