Long-term systemic effects of metal-on-metal hip arthroplasty: a systematic review

Abstract

Metal-on-metal (MoM) hip arthroplasty has been the subject of extensive research due to concerns regarding adverse reactions to metal debris and implant-related complications. This comprehensive review aimed to synthesize the existing literature on MoM hip arthroplasty outcomes, incorporating diverse study designs and examining various parameters such as histopathological features, blood metal ion concentrations, and implant survival rates. A systematic literature search was conducted across multiple databases up to January 2024, utilizing relevant keywords related to MoM hip arthroplasty. The inclusion criteria covered studies in English, involving human subjects who underwent MoM hip arthroplasty, with a focus on case series, observational studies, cohort studies, and randomized controlled trials. Eighteen studies were included, providing a diverse perspective on MoM hip arthroplasty outcomes. Key outcomes, including greater trochanteric fragmentation, spectrum of changes in adverse reactions to metal debris, peri-implant pseudotumor tissue characteristics, elevated blood cobalt concentrations, and complications associated with large-diameter MoM total hip arthroplasty, were systematically presented. The synthesis of findings revealed the multifaceted nature of MoM hip arthroplasty outcomes. Elevated blood cobalt concentrations emerged as a significant risk factor for early implant failure, while the spectrum of changes in adverse reactions highlighted the complexity of tissue responses. The comprehensive analysis contributes to the understanding of MoM hip arthroplasty outcomes, guiding future research and informing clinical decision-making in orthopedics.