High failure rate of the Duraloc Constrained Inlay

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Implant design

Background:

• Hip dislocations are a common complication following total hip arthroplasty.
• Recurrent dislocations present significant treatment challenges in some patients.
• Various implants and antiluxation mechanisms are employed in surgical management.

Purpose of the Study:

• To evaluate the clinical performance of the Duraloc Constrained Inlay in patients with recurrent hip dislocations.
• To assess the failure rates and mechanisms associated with this specific constrained inlay design.

Main Methods:

• A retrospective follow-up study was conducted.
• Nine Duraloc Constrained Inlays were implanted in 8 patients between October 2003 and November 2006.
• Patients were treated for recurrent dislocations post-total hip arthroplasty.

Main Results:

• All 9 implanted Duraloc Constrained Inlays failed.
• The failure mechanism involved the expanding ring being squeezed out of the polyethylene notch.
• Impingement, attributed to the implant design, was identified as the cause of failure.
• Three patients required revision surgery at the time of the study.

Conclusions:

• The Duraloc Constrained Inlay demonstrated unacceptably high failure rates.
• The design of the Duraloc Constrained Inlay contributes to its failure mechanism.
• This inlay is not recommended for managing recurrent hip dislocations.