Osteomyelitis: Recent advances in pathophysiology and therapeutic strategies

Abstract

This review article summarizes the recent advances in pathogenic mechanisms and novel therapeutic strategies for osteomyelitis, covering both periprosthetic joint infections and fracture-associated bone infections. A better understanding of the pathophysiology including the mechanisms for biofilm formation has led to new therapeutic strategies for this devastating disease. Research on novel local delivery materials with appropriate mechanical properties, lower exothermicity, controlled release of antibiotics, and absorbable scaffolding for bone regeneration is progressing rapidly. Emerging strategies for prevention, early diagnosis of low-grade infections, and innovative treatments of osteomyelitis such as biofilm disruptors and immunotherapy are highlighted in this review.

Keywords: Antibiotic; Arthroplasty; Bone infection; Fracture; Osteomyelitis.

Fig. 1

A diagram showing three categories of osteomyelitis. (A and B) Primary hematogenous (blood borne) spread of bacteria mainly afflicts the vertebral bodies at all ages or the metaphysis of skeletally immature patients. (C and D) Contiguous bone infection is most commonly seen with direct contamination of bacteria in open fractures or joint replacement surgery with prosthetic implants. (E) Vascular or neurologic disease associated osteomyelitis most commonly affects the lower extremity.

Fig. 2

A diagram summarizing the major differences between non-absorbable PMMA and absorbable biomaterial for a severely infected arthroplasty. When severe periprosthetic infection occurs, the prosthetic components are all removed, an antibiotic-loaded PMMA cement spacer releasing antibiotics is placed, then PMMA is removed once the infection has been controlled, bone grafting is performed to reconstruct the bone defect, and at a later date prosthetic components are reinserted. In contrast, when the infection is treated with an absorbable biomaterial scaffold releasing both antibiotics and osteogenic growth factors, bone grafting is not required. This shortens the time needed for bone reconstruction and reduces the total cost for a two-stage revision.