Implant Material As A Modifiable Risk Factor For Infection In THA: A Literature And Registry Review
Authors: Zimmermann M. , Leto A. , Porporati A.A. , Mannel H. 
Published: May 2020

Aim: Periprosthetic Joint Infection (PJI) is a rare but serious post-operative complication of hip replacement that often ends in complex implant revision and dramatically impacts the quality of life of the patient. Finally, costs associated with PJI significantly impact healthcare systems. Current research focuses on understanding the mechanisms of infection and identifying the risk factors related thereto. The objective of this study was to examine the potential impact of bearing materials on the incidence of infection in THA. Methods: Registries are a valuable tool to analyze large cohorts of THA patients and the influence of selected parameters on the clinical outcome of the surgeries. Data from THA patients recorded in the NJR, AOA and NZ registries were analyzed with respect to the incidence of infection. Material data and scientific publications were also reviewed to investigate if the incidence of PJI might be correlated with the specific bearing material used. Results: The use of metal bearings was consensually identified in all large patient cohorts as an independent risk factor for PJI. In contrast, using ceramic bearings was associated with a lower risk of revision for PJI.1 In vitro and ex vivo studies comparing the biological response to ceramic, metal and polyethylene materials are helpful to explain these findings. Metal exposure might activate the immune system and the released metal particles and ions might trigger adverse reactions with high inflammatory potential In contrast, extreme low wear ceramic bearings are well tolerated, show an excellent biological behavior 2,3,4,5,6 and might even support the wound healing process by initiating a healthy fibrotic pseudo-capsulation4. Furthermore, low wear is less likely to serve as a nidus for infection. Discussion and conclusion: Considering modifiable risk factors prior to THA is a key aspect for surgery success, implant longevity and patient satisfaction. Selecting a bearing material with enhanced biocompatibility like ceramics seems to have a measureable impact on the clinical outcomes. Favourable host-implant interactions might explain this observation. Literature: 1) Lenguerrand et al. Risk factors associated with revision for prosthetic joint infection after hip replacement: a prospective observational cohort study The Lancet, 2018DOI: https://doi.org/10.1016/S1473-3099(18)30345-1 2) Faye PA et al. Biomed Mater. 2017;12(1):015023 3) Cunningham BW et al. Journal of Neurosurgery: Spine. 2013;19(3):336-350 4) Savarino L et al. Acta Orthopaedica. 2009;80(2):162-167 5) Asif IM et al. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf. FBIOE.2016.01.00793 6) Asif I M et al. Characterisation and Biological Impact of Wear Particles from Composite Ceramic Hip Replacements. PhD thesis, University of Leeds (2018). http://etheses.whiterose.ac.uk/20563/ 7) Pitto et al Are ceramic-on-ceramic bearings in total hip arthroplasty associated with reduced revision risk for late dislocation? Clin Orthop Relat Res. 2015;473(12):3790–3795. doi:10.1007/s11999-015-4395-6