Abstract
Revision of a failed acetabular reconstruction in total hip arthroplasty (THA) can be challenging when associated with significant bone loss. In cementless revision THA, achieving initial implant stability and maximising host bone contact is key to the success of reconstruction. Porous tantalum acetabular shells may represent an improvement from conventional porous coated uncemented cups in revision acetabular reconstruction associated with severe acetabular bone defects.
Methods: We reviewed the clinical and radiographic results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects done with a hemispheric, tantalum acetabular shell (Trabecular Metal Revision Shell, Zimmer, Warsaw, USA) and multiple supplementary screws for fixation.
Results: At a mean follow-up of 40 (24–51) months, one acetabular shell had been revised in a patient with a Paprosky 3B defect. Two liner revisions were performed for recurrent instability, without porous tantalum shell revision. The clinical outcome showed significant postoperative improvement in all measured sub-scales, compared with baseline pre-operative scores (mean improvement in Oxford Hip Score of 40.0, p < 0.001, in WOMAC of 36.7, p < 0.001, Physical component SF-12 of 12.3, p =0.0003, mental component of SF-12 of 6.8, p = 0.006). Radiographic evidence of osseointegration using validated criteria (Moore’s criteria) was demonstrated in 39 of the 40 hips available for radiographic analysis at a mean of 30.9 months, by two independent observers. Of the remaining six hips, five hips were lost to follow-up and one radiograph demonstrated failure of the hip reconstruction secondary to loss of fixation and superior migration of the component.
Discussion: Cementless acetabular revision with the porous tantalum acetabular shell demonstrated excellent early clinical and radiographic results in a series of complex revision acetabular reconstruction associated with severe bone defects. The evidence of radiographic osseointegration suggests that outcome should remain favourable, however, further longer-term evaluation is warranted.
Correspondence should be addressed to Mr John Hodgkinson, BHS, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
