Introduction: In treatment for prosthetic hip joint infection (PHJI), the advantages of a 1-stage exchange over the classic 2-stage approach are the lower morbidity and earlier rehabilitation. Secondly, a recently published treatment algorithm for PHJI using well-defined selection criteria for 1-stage exchange had a 85–100% rate of cure for infection. Patient satisfaction after hip surgery is highly influenced by the functional result. We hypothesized that in our used algorithm the functional and radiological outcomes after a 1-stage exchange due to an implant-associated infection would be similar to a matched control group of 1-stage exchange due to aseptic loosening.

Material and Methods: Twenty-two cases (21 patients), with PHJI according to a well-defined definition, after 1-stage exchange of the prosthesis strictly according to the algorithm, with index-surgery between april 1996 and october 2004, were included in the studygroup. Case-matching was performed with aseptic revised cases for previous surgery, type of implant, use of transfemoral osteotomy, Charnley score, duration of follow-up, age, and sex. Outcome measures were perioperatively complications, functional results (Harris hip score, limping, and use of walking support) at two years, and the occurrence of revision for any reason and radiological loosening at latest follow-up. All outcomes were compared between both groups and with the results of the two stage revisions in our cohort. Finally, the eradication of infection was scored.

Results: In 86% of the 1-stage group (n = 19) there was an event-free follow-up for ≥ 2 years. The mean Harris hip score was 84, the incidence of limping 20% and 10% required two crutches. Two stems were revised due to aseptic loosening. Both functional and radiological outcomes were not different from the matched control group.

In the 2-stage group (n = 50) results were lower but not significantly, with 80, 30% and 28% respectively, and 2 stems and 1 cup were revised due to aseptic loosening.

One case (after one stage) developed an infection with a different pathogen and one case (after two stage exchange) had a relaps of infection.

Conclusion: By using the identical surgical technique in both septic and aseptic revision hip surgery, functional results are comparable between groups. These results indicate that 1-stage exchange according to a strict algorithm leads to a successful outcome in both maintaining functional mobility and eradicating infection.

The Liestal algorithmus for the treatment of infected total joint arthroplasties proposes the abovementioned three groups for revisions with exchange.

One stage exchange is executed in the presence of a adequate soft tissue situation and in absence of bacteria difficult to treat.

Two stage revision with spacer and a interval of 2–3 weeks until re-implantation is indicated in bad soft tissue situations

Two stage revision without spacer, a curative intravenous antibiotic treatment period of 6 weeks, a break of 2 weeks followed by reimplantation is indicated in the presence of bacteria difficult to treat.

All patients of group 1 and 2 were treated with antibiotics for 3 months – the first two weeks intravenous.

The ones of group 3 only, if during reimplantation positive tissue cultures were harvested.

We analysed 72 episodes of ITHA, 22 with 1-stage exchange, 29 with 2-stage exchange with spacer, 21 with 2-stage exchange without spacer. All 16 cases but 1 with bacteria difficult to treat were included in the last group. In this presentation only cases are included following the algorithm completely as published. All patient had an overall treatment with antibioticsIn all patients the index operation was done more than two years prior to the latest control. Two patients died shortly after the operation, the result remaining unknown. Another 3 died between 1 and two years after the operation. They were regarded as probably cured. Only one case of group 2 suffered of a relapse being caused by a coagulase negative staphylococcus being resistant against Rifampin. 2-stage exchange without spacer was then successful. One case of reinfection with another bacterium happened in the group 1.

Conclusion: This analysis is indicating, that the presented algorithm allows positive results regarding elimination in around 95% of the cases. Better results may be provable when basing on a larger number of patients. It seems, that the selection of so called “easier cases” for 1-stage exchange does not lead to a higher number of relapses and helps for an overall more economic way of treatment.