Severe Polyethylene Wear Requiring Revision Total Hip Arthroplasty in Three Dogs

Abstract

Polyethylene wear and implant failure may be a significant long-term complication of THA not previously recognized, which may be especially true when placed at an early age in a large breed, active dog, or in a dog with significant morbidity associated with other limbs. A successful revision was achieved in all 3 dogs. Additional investigation is warranted to document the risk factors associated with severe polyethylene wear in canine THA.

Polar gap after cementless total hip replacement in dogs

“…This indicates that the polar gaps did not predispose to cup migration . The low incidence of cup migration in our study vs the concern of osteolysis on the back side of the cup when the metal shell has a hole for ancillary screw fixation or perforations favors retention of the current cup design and surgical technique …”

Zurich Cementless Total Hip Replacement

“…The documentation and management of complications after the Zurich THR have been reported in several large case series and case reports 3,6,10,14,15 ; however, the follow-up and rate of complication differ depending on the published study ( Table 4). Overall complication rate (perioperative and postoperative) for Zurich THR is reported from 16.4% to 26.3%.…”

“…5,6 Recent reports, however, have described cases of significant wear of the acetabular components as a long-term complication that was not previously recognized. 6,15 The cup wear and failure were 4 years to 5 years after THR implantation and may occur more frequently in large breed, younger, more active dogs or dogs with significant morbidity associated with the other limbs. 15 Several improvements have been made to the early generations of Zurich THR implants to combat cup wear, including the use of polyether ether ketone (PEEK) in place of the ultra-high-molecular-weight polyethylene and a proprietary wear-reducing geometry of the cup inlay (Vezzoni A, personal communication, 2016) (Fig.…”

Deformation of the Zurich cementless acetabular cup caused by implantation in a canine cadaver model

“…Indeed, unacceptably high revision rates of metal‐on‐metal THA in humans has been partially attributed to metallic wear debris caused by cup deformation during implantation . The clinical significance of cup deformation with the traditional polyethylene‐lined cups is less clear, particularly due to the phenomenon of creep; however, accelerated polyethylene wear has the potential to cause major complications such as aseptic loosening, liner fracture, and cup fracture . These types of complications have been reported in approximately 6% of dogs treated with Zurich THA in a recent large scale retrospective study …”