ACETABULAR RECONSTRUNCTION WITH TRABECULAR TANTALUM AUGMENT IN LARGE BONE DEFECTS

Abstract

Introduction: Acetabular bone defects are critical and frustrating issue; indeed is possible to obtain good reconstruction with conventional Methods: (i.e. bulk graft, cage and cement) but good results are limited to short and mid term. Aim of this paper is to present reconstructive method based on filling the defect with an augment made of tantalum (augmentation technique).

Methods: We analized 42 cases from February 2005 to March 2009 with an average age of 63 years old with acetabular defect, scored 3A or more (4 patients had pelvic disjunction) according Paprosky classification.

The average age was very low, with 12 cases under 60 years (28,57%) and 21 under 70 (50%). 18 patients were re-revision (at time of surgery were at third or fourth surgical procedure) representing 54,2% of cases. Complete clinical, radiographic evaluation and survivorship analysis for the entire study cohort was performed from an average follow up of 26 months (min 6–max 55 months).

Results and Discussion: Preliminar results are encouraging: in only two case we had poor results with step pain and prescribed partial load and walking with two crutches, slight radiographic sign of migration where present at the last follow-up. These patients were previously submitted to many surgical procedures with significant bone loss, soft tissue damages and both with history of previous infection, classified as pelvic disjunction. One of these reported a ischiatic palsy.

In the remaining cases we obtained good functional recover, no failures at two years average of follow-up. 40 patients didn’t show hip or groin pain during stance position or walking, no bone resorption or implant mobilization were seen at radiographic follow-up. The HHS increases from 23,04 pre op to 85,15 post op. In no case were found clinical, radiographic, or biochemical signs of infection.

According with literature the rationale of augmentation technique with trabecular metal should give long lasting favourable results for its excellent bone ingrowth and mechanical properties.

Our results almost match the results of other authors. These brilliant results, partially due to osteoconductive proprieties of tantalum (despite we require time to confirmate), are certainly obtained thank to the optimal centre of rotation reconstruction, always close the physiological one.