Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Oct 18, 2021; 12(10): 768-780
Published online Oct 18, 2021. doi: 10.5312/wjo.v12.i10.768
Osteolysis in total hip arthroplasty in relation to metal ion release: Comparison between monolithic prostheses and different modularities
Francesco Manfreda, Egzon Bufi, Enrico Francesco Florio, Paolo Ceccarini, Giuseppe Rinonapoli, Auro Caraffa, Pierluigi Antinolfi
Francesco Manfreda, Division of Orthopedics and Trauma Surgery, Santa Maria della Misericordia Hospital, Perugia 06100, Italy
Francesco Manfreda, Egzon Bufi, Paolo Ceccarini, Auro Caraffa, Pierluigi Antinolfi, Department of Orthopedics and Traumatology, University of Perugia, Perugia 06100, Italy
Enrico Francesco Florio, Department of Orthopaedic and Traumatology, Infermi Hospital, AUSL Romagna, Rimini 47921, Italy
Giuseppe Rinonapoli, Department of Orthopaedic, University of Perugia, Perugia 06100, Italy
Author contributions: All the authors contributed equally to this work; Manfreda F and Florio E designed the research and collected the data; Ceccarini P and Rinonapoli G analysed the data; Manfreda F and Bufi E wrote the paper; Antinolfi P and Caraffa A contributed to manuscript revision; all authors approved the final version of the manuscript
Institutional review board statement: The study was reviewed and approved by the Internal Board of local Institution.
Informed consent statement: Informed consent statement was waived.
Conflict-of-interest statement: The Authors declare that there is no conflict of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at Participants gave informed consent for data sharing.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Francesco Manfreda, MD, Research Scientist, Surgeon, Department of Orthopedics and Traumatology, University of Perugia, Via G. Dottori, Perugia 06100, Italy.
Received: April 30, 2021
Peer-review started: April 30, 2021
First decision: June 16, 2021
Revised: June 30, 2021
Accepted: August 23, 2021
Article in press: August 23, 2021
Published online: October 18, 2021

Among the various complications associated with total hip arthroplasty (THA) periprosthetic osteolysis and wear phenomena due to the release of metal particles, are two of the most common and have been reported to be correlated because of inflammatory responses directed towards released particles that generally activate macrophagic osteolytic effects. Therein, new masses known as pseudotumors can appear in soft tissues around a prosthetic implant. To date, there is paucity of reliable data from studies investigating for any association between the above mentioned adverse events.


To investigate for the existence of any association between serum and urine concentrations of metal-ions released in THA and periprosthetic osteolysis for modular neck and monolithic implants.


Overall, 76 patients were divided into three groups according to the type of hip prosthesis implants: Monoblock, modular with metal head and modular with ceramic head. With an average f-up of 4 years, we conducted a radiological evaluation in order to detect any area of osteolysis around the prosthesis of both the femur and the acetabulum. Moreover, serum and urinary tests were performed to assess the values of Chromium and Cobalt released. Statistical analysis was performed to determine any association between the ion release and osteolysis.


For the 3 study groups, the monolithic, modular ceramic-headed and modular metal-headed implants had different incidences of osteolysis events, which were higher for the modular implants. Furthermore, the most serious of these (grade 3) were detected almost exclusively for the modular implants with metal heads. A mapping of the affected areas was performed revealing that the highest incidences of osteolysis were evidenced in the pertrochanteric region at the femur level, and in the supero-external region at the acetabular level. Regarding the evaluation of the release of metals-ions from wear processes, serum and urinary chromium and cobalt values were found to be higher in cases of modularity, and even more so for those with metal head. Statistical linear correlation test results suggested positive correlations between increasing metal concentrations and incidences areas of osteolysis. However, no cases of pseudo-tumor were detected.


Future studies are needed to identify risk factors that increase peri-prosthetic metal ion levels and whether these factors might be implicated in the triggering of local events, including osteolysis and aseptic loosening.

Keywords: Total hip arthroplasty, Peri-prosthetic osteolysis, Metal-ions, Monolithic total hip arthroplasty, Modular ceramic headed total hip arthroplasty, Modular metallic headed total hip arthroplasty

Core Tip: In this study a rigorous and statistically proven correlation was made between the release of periprosthetic metal ions in hip arthroplasty and the phenomenon of osteolysis, for severity and localization. A novel aspect of this study was that these evaluations were classified according to the types of prostheses: Monolithic, modular with ceramic head and modular with metal head. This was done so to conduct a contextual comparison between them. In fact, the results appeared quite clear, although further randomized trials and studies of higher scientific evidence will be needed.