Abstract
Managing severe acetabular bone defects during primary and revision total hip arthroplasty is a challenging problem. Standard treatment options for this cases is using of acetabular reconstruction type-Burch-Schneider rings. Unfortunately, the possibility of osseointegration of these implants with surrounding bone has always remained a contentious issue. The emergence in recent years of new designs of trabecular titanium, representing a symbiosis of acetabular reconstructive plates and modular cup helped to solve this problem on a completely new level.
The aim of this prospective study is to evaluate the short and mid-term clinical and radiographic outcomes of different types of acetabular revision cups - old and new design.
From 2006 to 2015, we performed 48 acetabular reconstruction with reconstruction rings CONTUR Smith and Nephew(group 1) and 34 operations with Delta TT Lima Revision system (group 2). The mean age of patients was 59.2 years (range 30–79). Indications for operations included fractures in acetabular region (10 pat – 12,2 %), acetabular nonunions with bone defects (14 pat – 17,1%), aseptic loosening with multiple dislocation of the primary implants in 38 cases (46,3%) and second stage of infection treatment in 20 cases (24.4%). Clinical and functional outcomes were evaluated by Harris Hip Score (HHS). Bone density in Charnley's zones was measured by dual-energy x-ray absorptiometry.
With CONTUR reconstruction rings were used 3 different types of bearing surface articulation (22 metal/polyethylene, 10 ceramic/polyethylene, and 16 oxinium/polyethylenel). With Delta TT Revision system were used metal/poly couples in 22 cases, ceramic/poly in 6 cases, and ceramic/ceramic couple in 4 cases. In two patients with high risk of dislocations were used double mobility system.
In all operations with CONTUR rings was used bone impaction grafting to fill cavitary defects (Paprosky 2B-3A), with Delta TT Revision system in 14 cases (41,2%) additionally TT augments were used.
In group 1 were 3 dislocations (6,3 %), 2 deep infections (4,2 %) and 4 aceptic loosenings with secondary instability of implants (8,3 %). In group 2 Trabecular Titanium showed a high capacity of osseointegration, providing good results in short-term follow-up. We registered only 2 dislocations (5,8 %) and 1 aceptic loosening (2,9 %). The mean HHS increased from 39.7 (range 23–62) preoperatively to 86.5 (range 68–98) at the last follow-up examination. The implanted cups were radiographically stable at the last follow-up visit (1 and 2 years) without radiolucent lines or periprosthetic osteolysis.
Conclusions
Delta Revision TT is a good solution for acetabular reconstruction even when there are cavitary and segmental bone defects. Modularity of this system make it possible to correct inlay position, center of hip rotation and minimising the risk of dislocation.
