TRABECULAR METAL FOR ACETABULAR DEFECTS IN HIP REVISION SURGERY. SHORT TERM CLINICAL AND RADIOGRAPHIC EVALUATION Giuseppe Marongiu1, Antonio Campacci2, Antonio Capone1

Introduction: The management of acetabular bone defects presents a challenge in revision total hip arthroplasty (THA). Porous tantalum acetabular implants provide a potential solution for dealing with significant acetabular bone loss. Tantalum acetabular implants are characterized by higher friction, higher porosity, and greater osteoconductivity than titanium mesh or chrome-cobalt beads. Aim: The aim of this study was to assess the early clinical and radiological outcome of revision of acetabular components using trabecular metal (TM) cups and augments for acetabular reconstruction. Material and methods: The study included 30 consecutive patients, 15 males and 15 females, with failed acetabular components after total hip arthroplasty. Mean age at the time of surgery was 67,5 years. Median follow up was 18 months (range, 12-24 months). All patients had conventional radiographs in anteroposterior (AP) view of the pelvis and lateral view of the hip in both preoperative e follow-up evaluations. According to Paprosky classification a Type II (10 IIa, 7 IIb, 7 IIc) defect was found in 24 hips, whereas a Paprosky type III (4 IIIa, 3 IIIb) defect was present in 7 hips. 16 patients had CT and Angio CT scan of the pelvis. All 30 patients underwent revision THA surgery using a trabecular metal acetabular shell, whereas in 6 cases augments were associated. In 3 cases were required cages. Patients were clinically evaluated according to Western Ontario and McMaster Universities scores score at 1 months, at 6 months and then at 1 year. Radiological evaluation investigated the restore of hip center of rotation, and signs of radiolucent lines and loosening. Results: At the most recent follow-up, 19 patients showed excellent results according to the WOMAC score, whereas 11 patient showed limitation in gait and function. The acetabular components and augments appeared osteointegrated, and no sign of loosening and radiolucent lines were found. There were no cases of hip dislocation. Conclusions: Based on these early clinical and radiological results, TM acetabular components and augments for acetabular defects (Paprosky II and III) appear to be a promising solution for this complex situation. We continue to monitor these patients, and a larger series with longer follow-up will be required to determine the long-term outcome of these augments.