Authors: Michael G Zywiel Loi’y H Mustafa Peter M Bonutti Michael A Mont
Publish Date: 2010/02/20
Volume: 35, Issue: 6, Pages: 797-802
Abstract
Dislocation is one of the most common complications of total hip arthroplasty The use of constrained liners is an option for the management of chronic hip instability typically used after other methods have failed The purposes of this study were to evaluate the overall clinical outcomes and failure rates of a tripolar constrained liner design to assess the radiographic outcomes of its use and to examine whether various factors such as abductor mechanism quality and history of previous revision surgeries were associated with an increased risk of failure Fortythree hips in 39 patients who had a mean followup of 51 months range 24–110 months were reviewed Ninetyone percent of the hips 39 of 43 hips did not need any revisions over the study period A new liner was implanted in all four failed hips with concurrent revision of the acetabular cup in three cases No further dislocations occurred in this group The mean hip score for surviving hips was 82 points range 38–100 points at final followup Radiographic evaluation revealed stable wellfixed acetabular components in all surviving hips without progressive radiolucencies No association was found between abductor muscle quality and the incidence of failure but patients who experienced a constrained liner failure were more likely to have undergone at least one previous hip revision operation Tripolar constrained acetabular liners can provide successful outcomes in patients with hip instability although it is important not to rely on the use of a constrained liner alone in an attempt to compensate for other correctable factors such as component positioning
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