Review Question - QID 213934

This patient is undergoing a stage 2 revision for MRSA and antibiotic cement is indicated. The best coverage would be with pre-mixed gentamicin cement with the addition of vancomycin for MRSA coverage.

Due to the concern for deep periprosthetic infections, there has been a proposed theoretical advantage of using antibiotics in primary total knee arthroplasties. However, this benefit has not been demonstrated in the literature. The current recommendation by the FDA is plain bone cement without antibiotics added for primary total knee arthroplasties. For total knee arthroplasty adding antibiotics to cement is only approved for the second stage of a two-stage revision. While often used in primary settings as well, this is technically off-label.

Jiranek et al. reviewed the use of antibiotic cement for infection prophylaxis in total joint arthroplasty. They discussed that antibiotic-loaded bone cement is only indicated for those at high risk of infection with primary and revision total joint arthroplasties. Additionally, they discussed that the mechanical and elution properties of pre-mixed antibiotic cement are better than hand-mixed antibiotic cement.

Want et al. looked at 2,293 patients that underwent primary TKA with a one-year follow-up. 10 patients were identified that had deep infections with no difference between plain cement and antibiotic laden cement. They concluded that in the setting of a primary TKA, antibiotic laden cement had no effect on prevention of deep infections.

Incorrect Answers:
Answer 1: This patient is undergoing a revision for infection and antibiotic cement would be indicated.
Answers 2 and 3: Antibiotic cement is indicated but vancomycin would offer better MRSA coverage.
Answer 4: Vancomycin cement is indicated but pre-mixed cement has been shown to have better elution and mechanical properties than hand-mixed versions.