Two-stage exchange arthroplasty

In two-stage exchange arthroplasty, the first-stage operation involves debridement of compromised soft tissue and bone, and removal of implanted materials (including the prosthesis, bone cement and, if present, ancillary screws, plates and wires). A spacer, which is antibiotic-impregnated, is inserted. Antibiotic therapy is given between the two stages—for choice of therapy, see Overview of empirical antibiotic therapy for arthroplasty device infections; for the duration of therapy, see discussion below. At the second-stage operation, the spacer is replaced by a new definitive prosthesis.

The timing between the two stages in two-stage exchange arthroplasty is primarily dependent on clinical factors (eg resolution of signs of infection, recovery of soft tissue envelope, planned duration of antibiotic therapy), but is also influenced by other factors (eg logistical considerations, level of patient discomfort).

The optimal duration of antibiotic therapy between the first and second stages is not well defined, but is usually at least 6 weeks. Extending this period to 12 weeks potentially increases the overall success rateBernard, 2021. Before implantation of the definitive prosthesis, signs and symptoms of infection should have resolved. Persistent spacer infection may require a repeat first-stage operation. Although inflammatory markers are usually monitored, concentration thresholds to guide whether a procedure should proceed have not been defined. Similarly, synovial fluid parameters are not adequately defined to justify routine re-aspiration to guide the timing of the second-stage operationAscione, 2021.

Withholding antibiotic therapy for 7 to 14 days before re-implantation is sometimes undertaken in practice to improve the microbiological yield of peri-prosthetic sampling at the second-stage operation. However, there are conflicting results from observational studies regarding the effect on overall success rate and it remains unclear if any patient group is likely to benefit from this strategyAalirezaie, 2019Ascione, 2019Davis, 2022.

At the second-stage operation, peri-prosthetic samples for culture should be taken intraoperatively. If culture results are positive, the choice of antibiotic therapy should be guided by the results of susceptibility testing. Antibiotics should be given for at least a further 6 weeks, although the optimal duration of therapy in this setting is also not well definedXu, 2019. Giving further antibiotics when second-stage cultures are negative is not routinely recommended because it confers a significant risk of adverse effects and further study is required to define a target population for whom the potential benefit outweighs the risk of harmde Beaubien, 2019Frank, 2017Xu, 2019.