Treatment of MRSA Bone and Joint Infections

Initial Treatment Approach

The Infectious Diseases Society of America recommends vancomycin plus rifampin as the first-line treatment for MRSA bone and joint infections due to rifampin's excellent penetration into bone and biofilm 1, 2, 3
Surgical debridement and drainage of associated soft-tissue abscesses is the mainstay of therapy and should be performed whenever feasible 2
IV vancomycin (15-20 mg/kg/dose every 8-12 hours, not to exceed 2g per dose) is the primary treatment for MRSA osteomyelitis, despite concerns about poor bone penetration 1, 3
Addition of rifampin (600 mg daily or 300-450 mg twice daily) to vancomycin is recommended due to rifampin's excellent penetration into bone and biofilm 3, 4
Minimum 8-week course of therapy is recommended for MRSA osteomyelitis 2
For septic arthritis, a 3-4 week course of therapy is suggested following drainage or debridement of the joint space 1, 5

Daptomycin 6 mg/kg/dose IV once daily can be used as an alternative treatment option 2
TMP-SMX 4 mg/kg/dose (TMP component) twice daily in combination with rifampin 600 mg once daily can be used as an alternative treatment option 2
Clindamycin 600 mg every 8 hours (if the isolate is susceptible) can be used as an alternative treatment option 2

For early-onset (<2 months after surgery) or acute hematogenous prosthetic joint infections with stable implants and short duration of symptoms (<3 weeks), initial parenteral therapy plus rifampin for 2 weeks is recommended 1, 6
Followed by rifampin plus a companion oral drug (ciprofloxacin, levofloxacin, TMP-SMX, tetracycline, or clindamycin) for a total of 3 months for hips and 6 months for knees 1, 6
For late-onset infections (>30 days after implant placement), device removal whenever feasible is recommended 4

For children with acute hematogenous MRSA osteomyelitis and septic arthritis, IV vancomycin is recommended as first-line therapy 7, 8
If the patient is stable without ongoing bacteremia, clindamycin 10-13 mg/kg/dose IV every 6-8 hours can be used if local resistance rates are low (<10%) 8
Minimum 3-4 week course for septic arthritis and 4-6 week course for osteomyelitis 8
Alternatives include daptomycin 6 mg/kg/day IV once daily or linezolid (dose based on age) 8

MRI with gadolinium is the imaging modality of choice for detection of early osteomyelitis and associated soft-tissue disease 2
ESR and/or CRP levels may help guide response to therapy 2
For patients with concurrent bacteremia, rifampin should be added only after clearance of bacteremia to prevent development of resistance 2

Vancomycin has shown failure rates of up to 35-46% in MRSA osteomyelitis, with a 2-fold higher recurrence rate compared to β-lactam therapy for S. aureus osteomyelitis 3
When using rifampin, always combine with another active agent to prevent emergence of resistance 3, 4
For long-term oral suppressive therapy in cases where device removal is not possible, options include TMP-SMX, tetracyclines, fluoroquinolones (with rifampin), or clindamycin 4
When using fluoroquinolones, be aware of potential for resistance development, especially if adequate surgical debridement is not possible 4