Prospective Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Feb 18, 2024; 15(2): 170-179
Published online Feb 18, 2024. doi: 10.5312/wjo.v15.i2.170
Assessment of the effectiveness of weight-adjusted antibiotic administration, for reduced duration, in surgical prophylaxis of primary hip and knee arthroplasty
Tosan Okoro, Michael Wan, Takura Darlington Mukabeta, Ella Malev, Marketa Gross, Claudia Williams, Muhammad Manjra, Jan Herman Kuiper, John Murnaghan
Tosan Okoro, Department of Arthroplasty, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry SY10 7AG, United Kingdom
Tosan Okoro, School of Medicine, Keele University, Staffordshire ST5 5BG, United Kingdom
Michael Wan, St Joseph’s Health Centre, Unity Health Toronto, Toronto M6R 1B5, Canada
Takura Darlington Mukabeta, Department of Arthroplasty, The Royal London Hospital, Barts Health NHS Trust, London E1 1BB, United Kingdom
Ella Malev, Marketa Gross, Claudia Williams, Muhammad Manjra, John Murnaghan, Department of Arthroplasty, Sunnybrook Holland Orthopaedic and Arthritis Centre, Toronto M4Y 1H1, Canada
Jan Herman Kuiper, Institute for Science and Technology in Medicine, Keele University, Staffordshire ST5 1BG, United Kingdom
Author contributions: Okoro T, Murnaghan J designed the research study; Okoro T, Wan M, Mukabeta TD, Williams C, Malev E, Manjra M, Gross M performed the research; Okoro T, Kuiper JH performed the statistical analysis; Okoro T, Kuiper JH, Murnaghan J analyzed the data and wrote the manuscript; All authors have read and approve the final manuscript.
Institutional review board statement: This study was approved by the Sunnybrook Health Sciences Centre, Toronto, Research Ethics Board in September 2018.
Clinical trial registration statement: The clinical trial is registered with, using identifier NCT00526890. Details can be found at
Informed consent statement: I wish to confirm that the above study was performed after approval as a quality improvement project by the Sunnybrook Health Sciences Research Department without the need for formal ethics committee approval and therefore did not require informed consent from the patients.
Conflict-of-interest statement: All the authors have no conflict of interest to declare.
Data sharing statement: No additional data are available.
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: Tosan Okoro, BSc, MBChB, PhD, FRCS, Consultant Trauma and Orthopaedic Surgeon, Honorary Senior Clinical Lecturer, Department of Arthroplasty, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Gobowen, Oswestry SY10 7AG, United Kingdom.
Received: November 8, 2023
Peer-review started: November 8, 2023
First decision: November 29, 2023
Revised: December 8, 2023
Accepted: January 5, 2024
Article in press: January 5, 2024
Published online: February 18, 2024

Prophylactic antibiotics have significantly led to a reduction in the risk of post-operative surgical site infections (SSI) in orthopaedic surgery. The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed, for the duration of the operation, the minimum inhibitory concentration of the likely organisms that are encountered. Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4% and 8% to between 1% and 3%. Controversy, however, still surrounds the optimal frequency and dosing of antibiotic administration.


To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime, combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty


Following ethical approval, patients undergoing primary total hip arthroplasty (THA)/total knee arthroplasty (TKA) with the old regime (OR) of a preoperative dose [cefazolin 2 g intravenously (IV)], and two subsequent doses (2 h and 8 h), were compared to those after a change to a new regime (NR) of a weight-adjusted preoperative dose (cefazolin 2 g IV for patients < 120 kg; cefazolin 3g IV for patients > 120 kg) and a post-operative dose at 2 h. The primary outcome in both groups was SSI rates during the 2 years post-operatively.


A total of n = 1273 operations (THA n = 534, TKA n = 739) were performed in n = 1264 patients. There was no statistically significant difference in the rate of deep (OR 0.74% (5/675) vs NR 0.50% (3/598); fishers exact test P = 0.72), nor superficial SSIs (OR 2.07% (14/675) vs NR 1.50% (9/598); chi-squared test P = 0.44) at 2 years post-operatively. With propensity score weighting and an interrupted time series analysis, there was also no difference in SSI rates between both groups [RR 0.88 (95%CI 0.61 to 1.30) P = 0.46].


A weight-adjusted regime, with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Keywords: Antibiotics, Weight-adjusted, Hip and knee arthroplasty, Surgical site infection

Core Tip: For patients in the study population undergoing primary lower limb arthroplasty, reducing the number of post-operative antibiotic doses had no adverse impact on surgical site infections incidence, at 2 years following surgery, if a weight-adjusted regime is used.