Abstract
Introduction: The prosthetic replacement of the infected knee is conditioned by the bone stock according with the A.O.R.I. We classified the bone defects on the infected knee following the Windsor protocol. When we find ourselves on a situation with T2-3 F2-3 and/or post-infection prosthetic replacements, we use tumoral knee prosthesis (“third prosthesis”).
The main causes of segmentary bone defects at the knee, appear after high energy injuries, tumoral resections and after infected total knee arthroplasties. Nowadays the treatment of these lesions, supposes a challenge to the orthopaedic surgeons due to the difficulty of the bone and soft tissue lesions.
Material and Methods: We present our first 35 cases involving tumoral knee prosthesis replacements after infected conminutive fractures around the knee, infected replacements and infections after tumoral resections.
Initially we used the prosthesis FINN model (BIOMET©) on 11 cases, while we have used the RHK model (BIOMET©) on the remaining 24. We followed the two-stage reimplantation using antibiotic PMMA spacers either manual or preformed depending on the defect’s size. Exposure of the stiff or ankylosed knee can be especially difficult when preoperative flexion is limited, so in these situations we use the Whitesides technique (tibial tubercle osteotomy). We used platelet derivated growth factors (inductors) associated with hydroxiapatite (conductors) with the goal to obtain the best possible osteo-integration.
Results: Our results are satisfying, considering we are confronting severe bone defects with a poor situation of soft tissues around the knee. We have not observed major complications involving the use of the inductors and conductors mentioned above.
Conclusions: We consider the use of tumoral knee prosthesis (“third prosthesis”) a useful technique which allows us to avoid the disability promoted by the knee arthrodesis, obtaining satisfactory results according to the severe lesions observed.
Correspondence should be addressed to Vienna Medical Academy, Alser Strasse 4, A-1090 Vienna, Austria. Phone: +43 1 4051383 0, Fax: +43 1 4078274, Email: ebjis2009@medacad.org
