Early Results of Adjuvant Topical Treatment of Recurrent Osteomyelitis with Absorbable Antibiotic Carriers

Abstract

Background Treatment of musculoskeletal infections principally consists of radical surgical debridement and systemic administration of antibiotics. Additional local antibiotic therapy is not yet generally established, and lacks evidence-based proof of efficacy. Nonetheless, there are a variety of practical approaches, as most specialised departments are unwilling to forego this option. The established polymethylmetacrylate (PMMA) carrier system has a number of practical disadvantages. This has led to the increased use of absorbable carrier systems, and those based on calcium sulphate have given particularly encouraging results. In this article, we present our experience with this procedure in the treatment of osteomyelitis. There is currently no standard procedure or algorithm for the use of local antibiotic carriers in the treatment of recurrent osteomyelitis. Material and Methods Between February 2014 and May 2015, a total of 93 patients were treated with an absorbable carrier of topical antibiotics based on calcium sulphate. These patients had suffered from a recurrence of osteomyelitis that had been unsuccessfully treated by the primary implantation of a PMMA chain and systemic antibiotics. The treatment algorithm consisted of radical debridement, followed by implantation of a commercial PMMA chain. If no remission of the infection was observed, the chains were surgically removed and replaced with an absorbable carrier system and antibiotics chosen in accordance with the resistogram. Pursuant to the classification of Cierny and Mader, 10 patients were classified as type I, 5 as type II, 55 as type III and 23 as type IV. The mean follow-up period was 11 months. Two carrier systems, Osteoset® and Herafill®, were purchased from Wright Medical Technology Inc., Arlington, TN, USA and Heraeus Medical GmbH, Wehrheim, Germany, respectively. These were used as supplied for tobramycin and gentamycin. In the case of Osteoset, it was also possible to add an additional arbitrary, water-soluble antibiotic. Systemic administration of antibiotics was carried out in parallel in accordance with the resistogram. Results The most common clinical entities were femoral (36 %) and tibial (29 %) osteitis. Vancomycin (38 %) and tobramycin (38 %) were the most frequently used topical antibiotics, followed by gentamycin (17 %), ceftriaxone (4 %), fosfomycin (2 %) and colistin (1 %). Systemic administration of antibiotics was carried out in parallel, in accordance with the resistogram. In 85 % of all patients, remission was achieved. Infections with methicillin-resistant Staphylococcus aureus (MRSA; 62 %) and Pseudomonas aeruginosa (43 %) showed significantly poorer remission rates. The bacterial spectrum was primarily composed of Staphylococcus aureus (28 %), Staphylococcus epidermidis (22 %), Pseudomonas aeruginosa (7 %) and Enterococcus faecalis (5 %), as well as Escherichia coli and Klebsiella oxytoca (4 %). Conclusion Topical adjuvant antibiotic therapy based on an absorbable carrier system offers an expedient extension of the treatment of osteomyelitis. The remission rate of 85 % for recurrent infections encouraged the use of a therapeutic alternative for many patients. We developed an algorithm for the treatment of osteomyelitis, which includes the application of local antibiotics with different compositions and absorbable carriers. We present early results of successful treatment of patients with recurrent osteomyelitis, after futile topical therapy with non-absorbable antibiotic chains.