Mechanisms of Adverse Local Tissue Reactions to Hip Implants

Abstract

Adverse Local Tissue Reactions (ALTRs) are one of the main causes of hip implant failures. Although the metal release from the implants is considered as a main etiology, the mechanisms, and the roles of the released products are topics of ongoing research. The alloys used in the hip implants are considered biocompatible and show negligible corrosion in the body environment under static conditions. However, modularity and its associated mechanically assisted corrosion have been shown to release metal species into the body fluids. ALTRs associated with metal release have been observed in hip implants with metal-on-metal articulation initially, and later with metal-on-polyethylene articulation, the most commonly used design in current hip replacement. The etiological factors in ALTRs have been the topics of many studies. One commonly accepted theory is that the interactions between the metal species and body proteins and cells generate a delayed type IV hypersensitivity reaction leading to ALTRs. However, lymphocyte reactions are not always observed in ALTRS, and the molecular mechanisms have not been clearly demonstrated. A more accepted mechanism is that cell damage generated by metal ions may trigger the secretion of cytokines leading to the inflammatory reactions observed in ALTRs. In this inflammatory environment, some patients would develop hypersensitivity that is associated with poor outcomes. Concerns over ALTRS have brought significant impact to both the clinical selection and development of hip implants. This review is focused on the mechanisms of ALTRs, specifically, the metal release process and the roles of the metal species released in the etiology and pathogenesis of the disease. Hopefully, our presentation and discussion of this biological process from a material perspective could improve our current understanding on the ALTRs and provide useful guidance in developing preventive solutions.

Mechanically Assisted Crevice Corrosion in a Metal-on-Polyethylene Total Hip Presenting With Lower Extremity Vascular Compromise

“…It is important to note, although MARS MRI is considered the most sensitive imaging modality, it may be normal in up to 30% of cases [22], and fluid alone in the joint may be a pathological finding. Infection is an important consideration in the differential diagnosis of postoperative joint pain and is difficult to distinguish from ALTRs based on joint cell count and differential and serum blood tests, as patients may present with both a leukocytosis and elevated inflammatory markers [5,21,22], which was observed in our patient who had both an elevated ESR and CRP.…”

“…Cooper et al have suggested the use of routine monitoring of serum Co and Cr levels [4], as evidence suggests that a Co-ion level greater than 1 ppb is strongly correlated with ALTRs [18,19]. Elevated intraarticular metal-ion levels may also suggest MACC and ALTRs and should be considered when aspirating a joint to rule out infection [20,21].…”

Potentially toxic metallic wear nanoparticles and trace metal ions release from metal-on-metal orthopedic implants in the human biological specimens: An Overview of in vivo and ex vivo clinical studies

“…Specific local tissue responses depend on the device or biomaterial and peri-implant tissue type as well as patient-related characteristics. The entire spectrum of local findings related to metal implants is incorporated into the term "adverse local tissue reactions" (ALTRs) to metal debris into the bodily fluids [184]. The term ALTRs refers specifically to local periprosthetic tissue changes and is one of the main causes of total joint arthroplasty (TJA) or total joint replacement (TJR) failures.…”

Improving fretting corrosion resistance of CoCrMo alloy with TiSiN and ZrN coatings for orthopedic applications

“…It is reported that more than 1 million total hip replacements are performed annually worldwide [2]. Current artificial hip implants typically consist of a titanium femoral stem pressfitted into a CoCrMo hemispherical femoral head that articulates with a titanium acetabular cup with a highly crosslinked polyethylene liner at the bearing surface, which is referred to as metalon-polyethylene (MoP) implants [3]. Although hip arthroplasty is generally a successful procedure, a significant number of patients have been observed with adverse local tissue reactions (ALTRs) to the implants, which are inflammatory lesions that destroy the soft tissues of the hip joint, affecting the prognosis of further clinical solutions [4][5][6][7].…”