Treatment of Chronic Osteomyelitis of the Femur by Intramedullary Antibiotic Perfusion (iMAP): A Case Report.

Introduction: Chronic osteomyelitis is difficult to cure definitively, because local areas are often covered with sequestrum and scar tissues with a poor blood flow; these may render systemic antibiotic administration ineffective. We present a case of chronic osteomyelitis that was successfully treated with continuous local antibiotic perfusion (CLAP) through an intramedullary antibiotic perfusion (iMAP) pin. Case Presentation: A 65-year-old man who suffered an episode of the right femoral osteomyelitis at the age of 15 years experienced a relapse at the age of 63 years. Systemic administration of antibiotics could not control the infection; thus, a surgery was performed. A bone marrow needle (i.e., an iMAP pin; diameter: 3 mm) was percutaneously inserted, from the front, distally and proximally to the cystic lesion in the distal femur. After washing through the iMAP pins, the pins were left indwelling. A closed drain tube was placed on the bone surface, which was close to the fistula of the bone marrow lesion. CLAP therapy was then initiated. Gentamicin was continuously infused through the iMAP pin at a rate of 2 mL/h and drained using the tube. Accordingly, 2.4 mg/mL, 1.2 mg/mL, and 1.2 mg/mL of gentamicin were administered for 4 days using two iMAP pins, for 5-8 days using two iMAP pins, and for 9-15 days using one iMAP pin, respectively, with a syringe pump. The iMAP pins and the drain tube were removed 15 days after the initiation of the CLAP therapy. The C-reactive protein level normalized 25 days postoperatively. The patient recovered full range of motion of the knee joint and recreational sports activity without recurrence of osteomyelitis for 5 years after the therapy. Conclusions: CLAP therapy allows local administration of a sufficient concentration of antibiotics and device removal after treatment is simple. This may be a novel treatment for chronic osteomyelitis.