A MODERN CONSTRAINED ACETABULAR COMPONENT FOR THE MANAGEMENT OF HIP INSTABILITY

The incidence of dislocation after primary THR has been quoted up to 2.25%, and between 2% and 20% for revision THR. We report clinical and radiological findings in 76 patients treated with a constrained liner for those considered at high-risk for dislocation, intraoperative instability or recurrent dislocations. Mean follow up was 12 months. Post operatively there were two cases of recurrent dislocation, one aseptic loosening and nine cases of deep infection. These results support that these liners have been used to treat, or in some cases prevent, instability after total hip replacement.

Experiences of a Peripheral Unit in Using a Tripolar Constrained Acetabular Component for Recurrent Dislocations following Total Hip Joint Replacements

Primary total hip arthroplasty is a successful procedure, although complications such as dislocation can occur. In certain patient populations if this is recurrent, it can be difficult to manage effectively. We present a retrospective analysis of our experience of using a capture/captive cup over an 8-year period for frail elderly patients who presented with recurrent hip dislocations. Our findings show no redislocations in our cohort and a survival analysis demonstrates just less than half surviving at 2 years after surgery. Furthermore, Harris Hip Scores were generally calculated to be good. A constrained acetabular component provides durable protection against additional dislocations without substantial deleterious effects on component fixation. Such components should be considered especially in a group of patients with comorbidities or those who are fragile, elderly, and low-demand in nature.

Trilogy-Constrained Acetabular Component for Recurrent Dislocation

32 patients received a Trilogy- or Trilogy-Longevity-constrained acetabular liner for recurrent dislocations after total hip replacement. The constrained liner was inserted into a well-fixed Trilogy acetabular shell with snap fit. At 1.8-year followup (range 3–63 months), 4 patients had suffered further dislocation(s) (12%), and one patient had revision surgery for a loosened acetabular shell. Radiologic evaluation detected no definitively loose components, but one patient with progressing radiolucent lines around the femoral component and one patient with an acetabular cyst were found, as well as a patient with a loose locking ring (but otherwise no failure). The nineteen patients who were available for the present followup had a mean Harris Hip Score of 81. The constrained liner is an effective method of dealing with recurrent dislocations in well-fixed components.

Omnifit Acetabular Component: A Solution to Preventing and Treating Dislocation

Purpose. To assess short- to medium-term outcome of the Omnifit constrained acetabular component in preventing dislocation in at-risk patients after total hip arthroplasty (THA). Methods. 81 patients (mean age, 77 years) underwent either primary or revision THA with an Omnifit constrained acetabular component and were followed up clinically and radiologically for a mean period of 24 months. Results. There was one dislocation and one revision for avulsion of the acetabulum. The remaining prostheses remained well fixed. Conclusions. In the short- to medium-term, the Omnifit constrained acetabular component is effective in preventing primary and recurrent dislocation in at-risk patients. Long-term follow-up is needed to assess whether good fixation is maintained. The Omnifit acetabular cup is recommended for elderly patients with limited life expectancy and functional demands.