Local antibiotic therapy in osteomyelitis

Abstract

The local delivery of antibiotics in the treatment of osteomyelitis has been used safely and effectively for decades. Multiple methods of drug delivery have been developed for the purposes of both infection treatment and prophylaxis. The mainstay of treatment in this application over the past 20 years has been non-biodegradable polymethylmethacrylate, which has the advantages of excellent elution characteristics and structural support properties. Biodegradable materials such as calcium sulfate and bone graft substitutes have been used more recently for this purpose. Other biodegradable implants, including synthetic polymers, are not yet approved for use but have demonstrated potential in laboratory investigations. Antibiotic-impregnated metal, a recent development, holds great promise in the treatment and prophylaxis of osteomyelitis in the years to come.

Keywords: Antibiotic; biodegradable; elution; methylmethacrylate; osteomyelitis.

Figure 1

Examples of use of PMMA antibiotic beads in open tibia fractures. (A) Tibial plateau fracture after implantation of beads and spanning external fixation. (B) Preoperative and (C) postoperative views of open distal tibia fracture with significant bone loss treated with open reduction and internal fixation with antibiotic bead placement. The PMMA beads provide a method for antibiotic delivery as well as dead-space management but do require a future operation for removal.

Figure 2

Use of a temporary antibiotic-impregnated prosthesis in the treatment of an infected allograft prosthetic composite total hip replacement with disassociation of the femoral and acetabular components. (A) Preoperative anteroposterior radiograph. (B) Intraoperative photograph at time of debridement. The femoral component was removed, autoclaved, and coated with antibiotic-impregnated PMMA cement and replaced as a temporary spacer prosthesis. (C) Anteroposterior radiograph after placement of the temporary prosthesis. (D) Anteroposterior radiograph after second-stage surgery 4 months later with placement of a segmental oncologic prosthesis with a constrained acetabular component.

Figure 3

Method of preparation of calcium sulfate pellets with implanted antibiotics. (A) Preparation of mixture of calcium sulfate with antibiotic powder. (B) Beads after hardening in foam mold. (C) Bead removal from foam mold. (D) Beads ready for implantation. (Photographs courtesy of Wright Medical Technology, Inc., Arlington, TN.)