Threaded rods versus arthrodesis nail as a static spacer for two-stage revision total knee arthroplasty

A spacer is required to maintain limb length and alignment and to provide a stable limb for mobilisation in two-stage revision total knee arthroplasty (rTKA) for periprosthetic joint infection (PJI). Static spacers are indicated in cases of massive bone loss, compromised soft tissues, and ligamentous and/or extensor mechanism insufficiency. The aim of this study was to compare the use of Ilizarov rods to arthrodesis nails for static spacer constructs in first-stage rTKA for PJI.

This was a retrospective cohort study of 40 patients who underwent two-stage rTKA for PJI between 2019 and 2022. Static spacers were used in all cases, constructed from Ilizarov rods 20 patients and nails in 20 patients. Data collected included number of previous revisions, patient age at first revision, comorbidities and identified organisms. Groups were compared based on outcome measures including complications, reoperations, length of stay and re-revision rates.

The use of Ilizarov rods showed higher rates of intraoperative complications (5% vs. 0%), readmissions (55% vs. 5%), and interstage re-operations (50% vs. 10%). Spacer-related complications occurred in 10 of 20 cases (50%) in the Ilizarov rod group, all due to spacer fractures, compared to none in the nail group (0%) (p < 0.05). Re-revision rates for infection after the second stage were similar between groups (p = 0.75).

The improved safety profile of arthrodesis nails support their use as a temporary static spacer between first and second stage rTKA.