Knee arthrodesis is a potencial salvage procedure for limb preservation in patients with multiple failures of Total Knee Arthroplasty (TKA) with massive bone loss and extensor mechanism deficiency. The purpose of the study is to evaluate the outcome of bridging knee arthrodesis using a modular and non cemented intramedullary nail in patients with septic failure Total Knee Arthroplasty. Between 2005 and 2013 (9 years), 15 patients (13 female and 2 male) with mean age 71.1 years (range 41 to 85) were treated at our Institution with septic two- stage knee arthrodesis using a modular and non- cemented intramedullary nail after multiple failures of septic Total Knee Arthroplasty. Mean follow- up was 70.1 months (24 to 108 months) with a minimum follow- up of 24 months. We evaluated the erradication of infection clinically and with normalization of laboratory parameters (ESR and CRP), limb length discrepancies and complications (periimplant fractures, amputation rates, wound healing disturbances) and the subjective evaluation of the patients after knee arthrodesis. We reported 11 cases of resolution of the infection (73.3 %), with good tolerance of the implant and a mean limb length discrepancies of 15 mm. Of these, 8 patients had been monitored over 5 years without recurrence of the infection. The mean number of previous operations was 4.9 (range 2 to 9). Two patients (13.3 %) required multiples surgical debridements for uncontrolled sepsis and finally underwent knee amputation. Coagulase- negative Staphylococci (SCN) were the most commom pathogen (53.3 %) followed by polimicrobian infections (26.7 %) One patient continues suppressive antibiotic treatment and 1 patient was treated with a one- stage custom- made arthrodesis nail exchange. Bridging knee arthrodesis using a modular and non- cemented intramedullary nail is a salvage procedure with acceptable results in terms of erradication of infection after septic faliure Total Knee Arthroplasty with restoration of limb length discrepancy. Despite these satisfactory results it is not without serious complications such as knee amputation.
Osteoarticular infections in paediatric population are primarily hematogenous in origin, although cases secondary to penetrating trauma, surgery or contiguous site are also reported. Despite being rare, numerous studies report infection relapse rates around 5 %. Osteomyelitis complications in children include septic arthritis, osteonecrosis of the bone segment, impaired growth. 7 years old male patient presented with history of traffic injury in January 2004. He sustained closed diaphyseal fracture of the right femur initially treated by elastic osteosynthesis. Four years after traffic injury he was diagnosed at our Institution of chronic femoral Osteomyelitis with positive cultures for methicillin sensible Staphylococcus aureus, requiring multiple surgical debridements and systemic antibiotic therapy. Five years follow- up the patient developed valgus deformity of his right knee (mechanical axis 11° genu valgum) with limb length discrepancy of 15 mm, intermalleolar distance of 15 cm and bone edema in external compartment of the knee (MRI). At this time the patient did not present any recurrence of septic process with normalization of laboratory parameters (ESR and CRP) and clinically asymptomatic. In February 2014, at the end of growth, a distal femoral varus osteotomy was used to treat valgus knee malalignment. Medial closing wedge osteotomy was performed satisfactorily using Tomofix® Osteotomy System (DePuySynthes). 18 months follow- up after varus osteotomy the patient progressed satisfactorily without pain and a normal function of his right knee. Correction limb length discrepancy was achieved (5 mm) with a normal alignment of his right limb (mechanical axis 3° genu valgum). Although Osteomyelitis is not very frequent in children population, its treatment requires not only prolonged antibiotic therapy but also multiple surgical debridements. We recommend monitoring over a long period of time children affected with Osteomyelitis in order to prevent and treat correctly impaired growth.
