Early Osseointegration and Lower Loosening Rates With Trabecular Metal Revision Cups in Acetabular Bone Loss: A Comparative Cohort Study.

BACKGROUND

Revision total hip arthroplasty (THA) in the presence of significant acetabular bone loss remains challenging, particularly in Paprosky IIC-III defects, where biomechanical stability and biological fixation are often compromised. Trabecular metal (TM) revision cups were developed to enhance osseointegration through high porosity and an elastic modulus closer to native bone, yet comparative real-world evidence against conventional revision cups remains limited in early follow-up.

METHODS

We conducted a retrospective comparative cohort analysis of patients undergoing acetabular revision THA for Paprosky IIC-III defects between 2022 and 2024. Ten patients were included, with six receiving TM cups (TM group) and four receiving conventional revision cups (control group). Radiographic osseointegration was assessed through secondary signs of ingrowth (absence of radiolucent lines, bone apposition, and absence of migration), while clinical fixation and early stability were evaluated using postoperative Harris Hip Score (HHS) and complication rates. Minimum follow-up was 12 months.

RESULTS

Early radiographic osseointegration was observed in 100% of the TM group versus 50% of the conventional group at 12 months. No cup migration or radiographic loosening occurred in the TM group, while two cases in the control group demonstrated early signs of mechanical instability. Mean postoperative HHS improved more robustly in the TM group (from 41.8 to 78.6) compared to controls (from 40.9 to 68.3). There were no infections or dislocations in either cohort. One patient who received a conventional cup required prolonged protected weight bearing due to suspected partial loss of early fixation.

CONCLUSION

In revision THA for Paprosky IIC-III acetabular defects, TM cups demonstrated markedly higher rates of early osseointegration and lower radiographic loosening at 12 months compared with conventional revision cups. These findings support the preferential use of TM technology in cases of advanced acetabular bone loss, where biological fixation is critical for long-term stability.