Failure of a constrained acetabular liner without reinforcement ring disruption
Jeffrey A Arthur, Derek F Amanatullah, Gannon D Kennedy
1University of California Davis Medical Center, Sacramento, CA. pedicesare@aol.com.
American Journal of Orthopedics (Belle Mead, N.J.)
|January 29, 2014
Summary
Dislocation after revision total hip arthroplasty (THA) can occur without damaging the implant. This case highlights potential causes like impingement or poor muscle function in revision hip surgery.
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
- Implant Design
Background:
- Total hip arthroplasty (THA) is a common procedure to address hip joint issues.
- Dislocation is a known complication of THA, influenced by various factors.
- Revision THA presents unique challenges and potential failure modes.
Observation:
- This case report details a dislocation event in a revision total hip arthroplasty.
- The dislocation occurred without any damage to the constrained liner or its containment ring.
- The specific implant involved was the Pinnacle Acetabular Cup with the Enhanced Stability Constrained Liner.
Findings:
- The dislocation mechanism in this revision THA was not due to implant structural failure.
- Potential causes identified include lever-out impingement and compromised abductor muscle function.
- Tension resulting from previous surgical interventions may also contribute.
Implications:
- This event represents a previously undescribed failure mode for this specific constrained liner system.
- Understanding these non-disruptive dislocation mechanisms is crucial for improving revision THA outcomes.
- Further investigation into biomechanical factors and surgical techniques is warranted to prevent such complications.
