Using Tantalum Augments for Major Acetabular Bone Defects in Revision Hip Surgery

Aim. The purpose of the study was to follow up the clinical and functional results of the patients with major acetabular bone defects in revision hip surgery. Materials and methods. The study was retrospective, over a period of six years (from January 2014 to January 2019), and included all the patients with hip replacement, with major acetabular bone defects, who needed Tantalum blocks substitution. 11 patients were included in the study (8 men and 3 women). The average age was 71 years (between 64 and 78 years old). The average follow up period was 23 months (between 11 and 36 months). Paprosky radiological classification was used for the preoperatory evaluation of the bone defects. In 9 cases, the bone defect was of type 2B Paprosky and in 2 cases, of type 3A. Harris score was determined preoperatory and postoperatory for the appreciation of functional results. Results. 6 patients were underwent replacement for coxarthrosis secondary to dysplasia, 2 patients for coxarthrosis secondary to aseptic necrosis and 3 patients for primary coxarthrosis. The average time elapsed from the moment of primary arthroplasty to the need of revision surgery was on average of 13 years (between 7 and 16 years). The postoperatory radiological evaluation showed an improvement of the hip rotation center from an average postoperative vertical position of 3.1 cm (between 1.2 and 4.6 cm) at an average postoperatory position of 1.1 cm (between 0.5 and 2.3). The average result of Harris score postoperatively was 36 (between 39 and 96). During the follow up period, no early loosening, infection or prosthesis dislocation was registered. Conclusions. The Tantalum Augments used in major acetabular bone defects in revision surgery represent a good option, correcting the hip rotation center, thus considerably improving the functional score.