Introduction: Total joint replacement is one of the most common, safe, and efficacious operations in all of surgery. However, one major long-standing and unresolved issue is the adverse biological reaction to byproducts of wear from the bearing surfaces and modular articulations. These inflammatory reactions are mediated by the innate and adaptive immune systems.Areas covered: We review the etiology and pathophysiology of implant debris-associated inflammation, the clinical presentation and detailed work-up of these cases, and the principles and outcomes of non-operative and operative management. Furthermore, we suggest future strategies for prevention and novel treatments of implant-related adverse biological reactions.Expert opinion: The generation of byproducts from joint replacements is inevitable, due to repetitive loading of the implants. A clear understanding of the relevant biological principles, clinical presentations, investigative measures and treatments for implant-associated inflammatory reactions and periprosthetic osteolysis will help identify and treat patients with this issue earlier and more effectively. Although progressive implant-associated osteolysis is currently a condition that is treated surgically, with further research, it is hoped that non-operative biological interventions could prolong the lifetime of joint replacements that are otherwise functional and still salvageable.

• Keywords
• Joint replacement, hip, joint arthroplasty, knee, osteolysis, particles, wear,
• MeSH
• Chemokines metabolism   MeSH
• Diagnosis, Differential MeSH
• Humans MeSH
• Joint Prosthesis adverse effects   MeSH
• Prosthesis Failure * MeSH
• Treatment Outcome MeSH
• Inflammation diagnosis   diagnostic imaging   etiology   physiopathology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Chemokines MeSH

BACKGROUND: The diagnosis of prosthetic joint infection (PJI) is still a challenge in some patients after total joint replacement. Interleukin-6 (IL-6) strongly participates in the arrangement of the host-bacteria response. Therefore, increased levels of IL-6 should accompany every PJI. PURPOSE: The aim of the study was to show diagnostic characteristics of serum IL-6 for the diagnosis of prosthetic joint infection (PJI). We also compared the diagnostic values of serum IL-6 with synovial IL-6 (sIL-6) and synovial C-reactive protein (sCRP). STUDY DESIGN: We performed a prospective study of 240 patients in whom serum IL-6 was determined before total hip (n = 124) or knee (n = 116) reoperations. The PJI diagnosis was based on the MSIS (Musculoskeletal Infection Society) criteria (2011). Receiver operating characteristic plots were constructed for IL-6, sIL-6, and sCRP. RESULTS: PJI was diagnosed in 93 patients, and aseptic revision was diagnosed in 147 patients. The AUC (area under curve) for IL-6 was 0.938 (95% CI; 0.904-0.971). The optimal IL-6 cut-off value for PJI was 12.55 ng/L. Positive and negative likelihood ratios for IL-6 were 8.24 (95% CI; 4.79-14.17) and 0.15 (95% CI; 0.09-0.26), respectively. The optimal sIL-6 and sCRP cut-off values were 20,988 ng/L and 8.80 mg/L, respectively. Positive and negative likelihood ratios for sIL-6 were 40.000 (95% CI; 5.7-280.5) and 0.170 (95% CI; 0.07-0.417), respectively. Negative likelihood ratio for sCRP was 0.083 (95% CI; 0.022-0.314). CONCLUSIONS: The present study identified the cut-off values for serum/synovial IL-6 and synovial CRP for diagnostics of PJI at the site of THA and TKA and separately for each site. The diagnostic odds ratio for serum/synovial IL-6 and synovial CRP is very good. Simultaneous positivity of serum IL-6 either with synovial IL-6 or synovial CRP almost excludes false negative detection of PJI at the site of interest.

• MeSH
• C-Reactive Protein metabolism   MeSH
• Prosthesis-Related Infections blood   diagnosis   microbiology   MeSH
• Interleukin-6 blood   MeSH
• Hip Prosthesis adverse effects   MeSH
• Humans MeSH
• Arthroplasty, Replacement, Hip MeSH
• Knee Prosthesis adverse effects   MeSH
• ROC Curve MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Synovial Membrane metabolism   pathology   MeSH
• Arthroplasty, Replacement, Knee adverse effects   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• C-Reactive Protein MeSH
• Interleukin-6 MeSH