Complications of Total Knee Arthroplasty: Standardized List and Definitions of the Knee Society

Background: Despite the importance of complications in evaluating patient outcomes after TKA, definitions of TKA complications are not standardized. Different investigators report different complications with different definitions when reporting outcomes of TKA.

Questions/purposes: We developed a standardized list and definitions of complications and adverse events associated with TKA.

Methods: In 2009, The Knee Society appointed a TKA Complications Workgroup that surveyed the orthopaedic literature and proposed a list of TKA complications and adverse events with definitions. An expert opinion survey of members of The Knee Society was used to test the applicability and reasonableness of the proposed TKA complications. For each complication, members of The Knee Society were asked "Do you agree with the inclusion of this complication as among the minimum necessary for reporting outcomes of knee arthroplasty?" and "Do you agree with this definition?"

Results: One hundred two clinical members (100%) of The Knee Society responded to the survey. All proposed complications and definitions were endorsed by the members, and 678 suggestions were incorporated into the final work product. The 22 TKA complications and adverse events include bleeding, wound complication, thromboembolic disease, neural deficit, vascular injury, medial collateral ligament injury, instability, malalignment, stiffness, deep joint infection, fracture, extensor mechanism disruption, patellofemoral dislocation, tibiofemoral dislocation, bearing surface wear, osteolysis, implant loosening, implant fracture/tibial insert dissociation, reoperation, revision, readmission, and death.

Conclusions: We identified 22 complications and adverse events that we believe are important for reporting outcomes of TKA. Acceptance and utilization of these standardized TKA complications may improve evaluation and reporting of TKA outcomes.