Infection in experimental hip arthroplasties

Abstract

The relationship between the route of inoculation, the dose of inoculum and the development of infection after prosthetic replacement has been determined in an animal model. The rabbit hip served as the model and a Staphylococcus aureus isolated from an infected human hip arthroplasty was introduced using different protocols. The 50% infective dose (ID50) was determined for comparative purposes. Contamination of the wound site with only a few bacteria was likely to result in infection. It was considerably more difficult to induce infection when the operation was performed without inserting the prosthesis, which suggests that the implant inhibits the body's mechanism for dealing with the insult. It was difficult to produce infection by inoculating the organisms into the bloodstream: if this inoculation was delayed till three weeks after operation the animals were often grossly septicaemic by the time the arthroplasty was infected. The results emphasise the importance of minimising intra-operative contamination and the efficacy of antibiotic cover.

Adhesion of Staphylococcus to orthopaedic metals, an in vivo study

“…Infected joint replacement models have been described by Belmatoug et al [5], Blomgren [6] and Johansson et al [14] for the knee, and by Southwood for the hip [20]. Chang and Merritt [8] and Nakamoto et al [18] have described subcutaneous models.…”

Pathogenesis of Prosthesis-Related Infection

“…The hematogenous prosthesis-related infection is based on two facts: Each of us can have bacteremia under normal situations, 40,42 and microorganisms in the bloodstream are able to leak in the artificial joint space. 6,70 Therefore, there may be some risk for all the patients with artificial joint replacement to develop hematogenous deep periprosthetic sepsis. 1 The diagnosis of hematogenous prosthesis-related infection must be based on the pathogen identity and time period, which can be often difficult to establish.…”

Influence of Materials for Fixation Implants on Local Infection

“…groups have used lower infection rates by graduating the inoculated bacteria (Petty et al 1985;Southwood et al 1985;Johansson et al, personal communication, 1992;Cordero et al 1994;Melcher et al 1994;Worlock et al 1994).…”