Septic Arthritis of Prosthetic Joints Empiric Therapy

Updated: Oct 13, 2021
  • Author: John L Brusch, MD, FACP; Chief Editor: Michael Stuart Bronze, MD  more...
  • Print

Empiric Therapy Regimens

Removal and replacement of an infected prosthetic joint is required, with the possible exception of those cases that are recognized within 30 days of implantation and are without any evidence of fistula formation. In such a case, simple debridement combined with antibiotic therapy could be considered. Please refer to the article on Septic Arthritis.

Empiric therapeutic regimens for septic arthritis of prosthetic joints, or peri-prosthetic joint infection (PJI), have been based primarily on physical findings, history, and in particular, the results of the Gram stain of synovial fluid.The most common pathogens are MSSA, MRSA ,CoNS, coliforms, and N gonorrhea. [1, 2, 3, 4, 5, 6, 7, 8]  Inadequate initial treatment often results in unsatisfactory outcomes because of continued bone and tissue damage brought about by unchecked infection.

It is difficult to differentiate aseptic loosening of prosthetic joints from low-grade chronic periprosthetic joint infections. In such cases, debridement and measurement of circulating biomarkers, including various blood tests for bacterial DNA, hold promise in making these determinations. The specificity of procalcitonin measurements is low in these situations (27.8%). The combination of a C-reactive protein (CRP) level [9] greater than 0.3 mg/dL and IL-6 level greater than 5.12 pg/mL is superior, with a sensitivity of 75% and specificity of 98.2% in high-risk patients. [10, 11]

General recommendations

Cultures of blood, synovial fluid, and, if possible, periprosthetic tissue, should be obtained before initiating antibiotic therapy for PJI. [12]

Duration of total antibiotic therapy is at least 6 wks extended to 12 weeks.  At least 10 days of such should be given parenterally. Ongoing suppressive antibiotic therapy is indicated when not all the infected prosthetic material and surrounding bone and soft tissue can be removed.

Rifampin 600 mg PO q24h should be added for staphylococcal infections whenever infected prosthetic material is retained. To prevent the development of resistance, rifampin should be started 2 days after initiation of antibiotic therapy. [1, 2, 3, 4]

For coverage of MSSA, MRSA, CoNS, and E faecalis, vancomycin commonly is begun at 15 mg/kg IV q12h in those with normal renal function. Vancomycin has lost a good deal of effectiveness against these pathogens. In seriously ill patients with renal sufficiency, it is challenging to reach an adequate therapeutic level (5-12 µg/ML). In addition, MRSA, MSSA, CoNS, and E faecalis have developed varying degrees of resistance. [8, 13, 14]  

The author recommends the use of linezolid for empiric coverage of all streptococci, MSSA, MRSA, and most isolates of CoNS. When given longer than 2 weeks, significant hematological side effects may occur, including thrombocytopenia, pancytopenia, leukopenia, and anemia, as well as peripheral neuropathies

Ceftriaxone provides coverage against gram-negative enterics, as well as N gonorrhea and a large variety of streptococci. The author's usual empiric coverage for patients with PJI would be a combination of ceftriaxone and linezolid.

Daptomycin is effective against aerobic gram-positive organisms such as MSSA, MRSA, CoNS, VSE,and VRE. Previous treatment with vancomyin can markedly reduce its effectiveness. Addition of nafcillin or ampicillin lowers the daptomycin MIC versus S Aureus and enterococci, respectively.

Minocycline has good coverage against MRSA, VRE, and enteric organisms.

Aztreonam is useful in covering gram-negative aerobes in those with severe beta-lactam allergies. [15, 16]