Trunnionosis After Total Hip Arthroplasty: A Review of the Etiology, Diagnosis, and Management.

Trunnionosis implies wear and corrosion at the head-neck junction of the femoral component in a total hip replacement, leading to the release of metal ions and particulate debris. It has become a recognized complication following total hip arthroplasty (THA), particularly in modular implant designs. These wear processes can result in adverse local tissue reactions (ALTRs), implant loosening, and systemic effects in severe cases. Factors contributing to trunnionosis include implant design, patient anatomy, activity level, and surgical technique, all of which influence the degree of mechanical wear and corrosion at the taper interface. Clinical presentation is variable, ranging from localized pain and limp to systemic symptoms of metal hypersensitivity or toxicity. Diagnosis requires a comprehensive approach, integrating clinical evaluation, imaging studies such as magnetic resonance imaging (MRI), serum metal ion levels, and synovial fluid analysis to differentiate trunnionosis from infection and other causes of implant failure. Management strategies focus on revision surgery, involving debridement of ALTRs, exchange of the femoral head, and addressing implant instability or loosening. As the use of modular implants continues to rise, understanding the etiology, diagnosis, and management of trunnionosis is essential to improving outcomes for patients undergoing THA.