Abstract
Purpose: To report a series of unexpected femoral neck failures in a series total hip replacement surgeries using a modular femoral component.
Method: A series of 443 hip replacement patients received modular necks as part of a non cemented hip replacement with ceramic articulations at the acetabulum and femoral head interface. The first implant of the device was on June 8, 2004 and the last on June 12, 2009. Ninety-one of those patients were enrolled in a RSA study of component stability within the proximal femur.
Results: The index fracture of a femoral neck occurred on March 8, 2009 when the patient (28 months post hip replacement) reported a fall. Subsequently five patients have had a fracture of the modular neck. There were five fractures within the RSA study group and one within the non study group (all occurred 17 months to 30 months post op). All fractures were long necks (10.5 mm). There was no difference in femoral component micromotion as measured with RSA between the fractured group and the unrevised group.
Conclusion: Initial non-destructive testing of one retrieval revealed fatigue failure of the femoral neck. An independent study of all relevant data was implemented which included destructive testing of the implants and clinical data with respect to patient activity. We report the outcome of all those investigations.
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