Antibiotic bone penetration. Concentrations of methicillin and clindamycin phosphate in human bone taken during total hip replacement.

Clindamycin phosphate or methicillin was given preoperatively to 47 patients undergoing hip operations for arthritis. Serum, cortical and cancellous bone specimens were simultaneously obtained during the operation and assayed for antibiotic concentrations. Both gave levels in bone/serum concentration ratio significantly higher for clindamycin than methicillin. No patients studied developed deep infection. It is concluded that clindamycin phosphate and methicillin give comparable concentrations in bone which exceed the minimal inhibitory antibiotic concentration of gram-positive pathogens that frequently cause infection after orthopedic surgical procedures.