Two-stage revision surgery for hip prosthesis infection using antibiotic-loaded porous hydroxyapatite blocks

Background Infection of a hip prosthesis is one of the most severe complications encountered in orthopedic practice. Two-stage reconstruction using an antibiotic-impregnated cement spacer has become a popular procedure for the treatment of this condition. However, there are some disadvantages with the use of antibiotic-loaded cement, including low biocompatibility, a very low release ratio, and the possibility of thermal damage to the antibiotic. We have developed an effective drug delivery system for osteomyelitis in which porous hydroxyapatite (HA) blocks are loaded with an antibiotic by the vacuum method. We report here a modification of this delivery system applied for the first stage of two-stage reconstruction surgery against infected hip prosthesis. Patients and methods Eight consecutive patients who developed hip prosthesis infection underwent two-stage revision total hip arthroplasty (THA) using antibiotic-loaded porous HA blocks prepared by the vacuum method. Thorough debridement and insertion of antibiotic-loaded HA blocks was performed in the first stage, followed by conversion to THA after eradication of infection in the second stage. Results The mean interval between the stages was 16.8 weeks. There were no complications related to the use of the antibiotic-loaded HA blocks. The patients were followed up for an average of 49 months with no evidence of recurrent infection. The mean Japanese Orthopedic Association hip score improved from 45.1 before surgery to 79.6 at the latest follow-up. Interpretation This simple approach utilizing antibiotic-impregnated HA blocks prepared by the vacuum method is considered to be effective for treatment of hip prosthesis infection.