A retrospective review in the Journal of Arthroplasty found that the most frequent causes of failed TKA at less than 2 years post op were aseptic loosening, instability, infection, arthrofibrosis, and malalignment. The etiologies characterizing failed total knee arthroplasties were examined in 844 patients at six centers. The authors note that these early causes of failure are factors that are directly under the surgeon’s control.
St. Louis Joint Replacement Institute, SSM DePaul Health Center, St. Louis, Missouri.
- Revision knee data from six joint arthroplasty centers were compiled for 2010 and 2011 to determine mechanism of failure and time to failure. Aseptic loosening was the predominant mechanism of failure (31.2%), followed by instability (18.7%), infection (16.2%), polyethylene wear (10.0%), arthrofibrosis (6.9%), and malalignment (6.6%). Mean time to failure was 5.9years (range 10 days to 31years). 35.3% of all revisions occurred less than 2years after the index arthroplasty, 60.2% in the first 5years. In contrast to previous reports, polyethylene wear is not a leading failure mechanism and rarely presents before 15years. Implant performance is not a predominant factor of knee failure. Early failure mechanisms are primarily surgeon-dependent.