Single trabecular titanium Cup-Cage for acetabular bone defects during revision hip arthroplasty: Mid-term outcomes

Severe acetabular bone loss remains a major challenge in revision total hip arthroplasty (rTHA). Traditional cup-cage techniques can provide stability but are associated with technical complexity and mixed long-term outcomes. The Delta TT system, a trabecular titanium construct functioning as a single cementless cup-cage, may combine biological fixation with mechanical reliability. This study aimed to evaluate its mid-term clinical and radiographic outcomes in complex acetabular reconstructions.

In this prospective cohort (2018-2021), 64 patients (mean age: 68.4 years) with Paprosky type II (n = 38) or type III (n = 26) acetabular defects underwent rTHA using the Delta TT system. Functional outcomes were measured with the Merle d'Aubigné and Postel score preoperatively and at a mean 48-month follow-up. Radiographs were assessed for implant stability, osteointegration, and radiolucency. Complications and re-revision rates were documented.

Stable radiographic fixation was achieved in nearly all cases. Two patients demonstrated minor, non-progressive radiolucency without clinical significance. Osteointegration was evident in all hips within 12 months. Functional outcomes improved significantly, with mean scores increasing from 8.2 preoperatively to 15.6 at final follow-up (p < 0.001). At mid-term, 75% of patients achieved good-to-excellent clinical results. The complication rate was low, and no re-revisions were required for aseptic loosening.

The Delta TT system offers a reliable and biologically favorable solution for managing severe acetabular defects in rTHA. Its porous trabecular titanium structure and modular design promote durable fixation, radiographic stability, and significant functional recovery, with low complication rates. These mid-term results support its role as a valuable reconstructive option in complex revision hip arthroplasty. Long-term and comparative studies are warranted to further validate durability and outcomes.