Penetration of methicillin, oxacillin, and cephalothin into bone and synovial tissues.

The penetrations of methicillin, oxacillin, and cephalothin into cortical bone and synovial tissues were studied 1 h after their intravenous administration in 105 patients having arthroplasty of the hip. Although the lowest serum levels were noted with cephalothin (P < 0.01), more patients receiving cephalothin achieved osseous drug levels inhibitory to staphylococci (P < 0.01). Differences in the penetration of the three agents into synovial tissues were not statistically significant.