Double-trabecular metal cup technique for the management of Paprosky type III defects without pelvic discontinuity

Modular reconstruction systems based on trabecular metal (TM) prosthetic components have been increasingly used in the last decade for the management of severe acetabular bone defects. The aim of this study was to assess the clinical and radiographic outcomes of double-cup technique for the management of Paprosky type III defects without pelvic discontinuity.

A retrospective review was performed for all patients undergoing acetabular reconstruction with 2 TM cups at a tertiary referral centre between 2010 and 2015. Harris Hip Scores (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were evaluated preoperatively and at the latest follow-up. Radiographic assessment of the hip centre of rotation (COR) position and leg length discrepancy (LLD) was performed preoperatively and postoperatively. Osteolysis and radiolucencies, loosening of the implants, and heterotopic ossifications were evaluated with the latest follow-up radiographs.

Patients included 5 men and 11 women (16 hips) with an average age of 68 (45–81) years. Acetabular bone defects included 9 Paprosky type IIIB and 7 type IIIA defects. No pelvic discontinuities were registered. The mean follow-up was 34 (24–72) months. HHS and WOMAC scores, LLD and COR position significantly improved after surgery. In only 1 (6.3%) hip a not progressive radiolucent line adjacent the acetabular construct was noted. Heterotopic ossifications were found in 2 (12.5%) hips. No patients underwent acetabular components revision surgery for any reason.

The double-cup technique could be considered an effective management of selected Paprosky type III defects without pelvic discontinuity providing excellent clinical and radiographic outcomes in the short term.