Spontaneous Dissociation of Offset, Face-Changing Polyethylene Liners from the Acetabular Shell

• DOI: 10.2106/jbjs.k.00506
• Publication Date: 2012-04-19T21:41:36Z
• Authors: Chancellor F. Gray; Ryan E. Moore; Gwo-Chin Lee
• Keywords: Adult; Reoperation; Arthroplasty, Replacement, Hip; Middle Aged; Prosthesis Design; Osteoarthritis, Hip; Prosthesis Failure; 03 medical and health sciences; 0302 clinical medicine; Polyethylene; Humans; Female; Hip Prosthesis; Aged

Background: Dissociation of the polyethylene liner from acetabular shell is an uncommon event. Offset, face-changing liners theoretically increase femoral head coverage, allow for larger heads with smaller cup diameters, and offer improved stability without risk impingement. However, we present four cases dissociations that necessitated revision hip surgery. Methods: Four patients spontaneous offset, underwent arthroplasty between January 2007 June 2010. All were women average age fifty-three years. involved combination a Pinnacle component liner. We reviewed presenting signs symptoms associated analyzed radiographs position. Results: dissociation occurred direct trauma squeaking sounds reported by patient. The abduction angle was 55° (range, 51° to 60°) anteversion 21.5° 17° 24°). Examination dissociated at time surgery revealed plastic deformation rim posterosuperiorly eleven o'clock position on right one left hip. Conclusions: vertically positioned resulted in impingement patients. Proper positioning, rather than routine use uniquely designed liners, critical maximizing implant total arthroplasty. Level Evidence: Therapeutic IV. See Instructions Authors complete description levels evidence.