Arch Orthop Traumat Surg ( 1982) 100:49-53 Archives of Orthopaedic and Traumatic Surgery © J F Bergmann Verlag 1982 Arthrodesis After Infected Knee Arthroplasty Using an Intramedullary Nail* Reports of Four Cases Kaj Knutson and Lars Lidgren Department of Orthopaedic Surgery, University Hospital, S-22185 Lund, Sweden Summary In the treatment of knee arthroplasty fail- ures intramedullary nail arthrodesis may be used to achieve stability if compression arthrodesis is not indi- cated or has failed. Four case reports illustrate this technique in the treatment of infected knee arthroplasties A two-stage procedure is recommended, first eradication of all foreign and infected material and temporary use of gentamicin beads and four weeks later intramedullary nail fixation and massive bone transplantation The nailing technique is discussed. Zusammenfassung Bei der Behandlung einer geschei- terten Kniegelenks-Alloarthroplastik kann eine intra- medullare Nagelarthrodese verwendet werden, um eine Stabilisierung zu erreichen, und zwar dann, wenn eine Kompressionsarthrodese nicht indiziert ist oder bereits vorher versagt hat. Die Berichte von vier Fallen illustrieren diese Technik bei der Behandlung von infizierten Knie- gelenksplastiken. Ein Zwei-Stufen-Verfahren wird empfohlen: Zuerst wird eine Ausraumung aller Fremdk 6 rper und des infizierten Gewebsmaterials unter voribergehen- der Verwendung von Gentamycin-Kugeln durch- geftihrt Vier Wochen danach erfolgt eine intramedul- lare Fixation und eine massive Knochentransplanta- tion Die Nagelungstechnik wird diskutiert. Introduction Arthrodesis as a primary treatment for arthropathy is today easily performed resulting in fusion in nearly all * Grants Swedish Medical Research Council (Project No. B 81-16 X-D 4776-07) and Stiftelsen fr bistand t vanfora i Skane, Helsingborg cases (Charnley and Baker 1952) The use of external fixation as a single frame (Charnley 1948) or a double frame (Connes 1973) has long been used for knee- fusion Arthrodesis of the knee in the treatment of infected knee arthroplasty has a high failure rate. Twenty-five to 45 per cent non-unions have been reported when treating infected hinged endopros- theses (Hageman et al 1978 ; Brodersen et al 1979). We have used compression arthrodesis with exter- nal double frame fixation in the treatment of infected knee endoprostheses during the last 5 years As one of our patients failed to fuse despite adequate external fixation, internal fixation became necessary (Case 1). Intramedullary reaming and rodding have been sug- gested as a method to achieve arthrodesis in difficult cases (Macys and Froimson 1973) Diaphysary pseud- arthrosis with a low grade infection has been intra- medullary reamed and rodded under systemic anti- biotic treatment without septic complications (Chri- stensen 1973 ; Lidgren and T 6 rholm 1980 ; Lidgren and Onnerfilt 1981) The aim of the following study is to present four arthrodeses using a modified long Kiint- scher nail in the treatment of septic knee arthroplasty. Case Reports Case 1 A 46-year-old woman with seronegative rheumatoid arthritis and severe cartilage destruction of the right knee was treated with a Gu 6 par hinged endoprosthesis A medial trans- position of the patellar ligament with staple fixation was done because of peroperative patellar luxation Five years post- operatively a three centimetre large bursa with amorphous content was found over the staple The bursa and staple were extracted and peroperative bacterial cultures were negative. The incision did not heal and septic arthritis and a fistula devel- oped One month later when the endoprosthesis was extracted, alfa-streptococci were found in bacterial cultures from 5/5 0344-8444/82/0100/0049/$ 1 00