Acceptable survival of one-and-a-half-stage exchange arthroplasty with cement augmentation for periprosthetic joint infection

Abstract Purpose: To compare the aseptic survival of 1.5-stage exchange arthroplasty for periprosthetic joint infection (PJI) with and without cement augmentation using an autoclaved original femoral component and a new polyethylene insert (PE). Methods: Among 1.5-stage exchange arthroplasties without reinfection, 42 cases with cement augmentation (Group C) and 88 cases without cement augmentation (Group N) were retrospectively reviewed. The cement augmentation technique was applied when joint stability could not be achieved using the thickest PE. Demographics were not significantly different between the groups. The hip-knee-ankle angle (HKA) and component positions were measured; the proportions of appropriate HKA and component positions (HKA≤0±3°, α≤95±3°, β≤90±3°, γ≤3±3°, and δ≤87±3°) were investigated. Survival and failure rates were analyzed, and failure was defined as reoperation owing to aseptic failure. The risk factors affecting survival were investigated in terms of demographics, cement augmentation, inappropriate HKA and component position for all patients in both groups. Results: Although the average HKA and component positions were not different, appropriate proportion of coronal and sagittal PE position were significantly lower in the group C (appropriate β, 57.1% vs 90.9%; appropriate δ, 38.1% vs 77.3%; p<0.001, respectively). The 1-, 2-, and 5-year survival rates were 76.2%, 71.4%, and 71.4% in group C and 89.8%, 86.4%, and 81.6% in group N, respectively (p=0.063). The failure rate was not significantly different, despite the higher failure rate in group C (28.6% vs. 18.2%, p=0.253). The significant factor affecting the survival was only the inappropriate coronal positioning of the PE (β>90±3°) in overall cases (odds ratio=2.957, p=0.016). Conclusion: The cement augmentation technique used to compensate for instability allows acceptable survival in 1.5 stage exchange arthroplasty. However, care is required when using this technique in the appropriate PE position to ensure favorable survival.