Phage Therapy for Bone and Joint Infections: Challenges, Biological Dynamics, and Therapeutic Prospects in the Era of Antimicrobial Resistance

Bone and joint infections (BJI) remain among the most challenging conditions in orthopaedics due to their complex pathophysiology, frequent association with biofilm formation on bone and implant surfaces, and the rising prevalence of antibiotic-resistant pathogens. Conventional antibiotic therapies, although central to current clinical practice, are often limited by poor biofilm penetration, disruption of the host microbiota, and the increasing emergence of multidrug resistance, particularly in chronic infections such as osteomyelitis and prosthetic joint infections. This review provides a comprehensive exploration of bacteriophage therapy as a targeted, non-antibiotic strategy for the management of BJIs. Bacteriophages exhibit unique biological characteristics, including strict host specificity, self-amplifying antibacterial activity, and the capacity to disrupt biofilms through bacterial lysis and phage-derived enzymes. Evidence from in vitro investigations, animal models, and emerging clinical studies demonstrates the promising efficacy of phages and phage lysins against key BJI pathogens, particularly Staphylococcus aureus, with favourable safety profiles and encouraging rates of infection control, especially when used as adjuncts to surgery and antibiotics. Despite this potential, challenges such as narrow host range, variable pharmacokinetics, immunogenicity, and underdeveloped regulatory frameworks continue to limit widespread clinical adoption. Addressing these barriers through standardized phage selection, improved delivery strategies, combination therapies, and coordinated regulatory efforts will be critical to realizing the full therapeutic potential of phage-based interventions for antibiotic-resistant bone and joint infections.