<p>Hip instability can be successfully managed using a six-part algorithm that helps surgeons identify and treat variations in instability, according to a presenter at the Current Concepts in Joint Replacement Winter Meeting, here.</p><p>“Our conclusion, then, is this demonstrates a six-part algorithm for treating an unstable hip,” Wayne G. Paprosky, MD, said. “We think it is probably one of the most successful series of its size. We are now advocating the use of tripolar constrained liners where possible, especially in these type III abductor deficiencies.”</p><p>Paprosky and colleagues performed a retrospective analysis of 77 consecutive hip arthroplasties that were revised due to instability, according to the abstract. They identified six variations of instability and placed patients in numbered from one to six based on the etiology of the instability, which included acetabular component malposition, femoral component malposition, abductor deficiency, impingement, late wear, or “unclear etiology.”</p><p>Once the instability was identified, type I and II instabilities were treated with component revision, type III and VI instabilities were treated with a constrained liner, type IV instabilities were treated by removing the impingement and type V was treated with a liner change.</p><p>The success rate was 84.4% for all treatments of instability. When treatment for type III abductor insufficiencies were removed, which accounted for 8 of 12 revisions in the study, the success rate was 92%, according to the abstract.</p>