Retrospective Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Mar 18, 2023; 14(3): 136-145
Published online Mar 18, 2023. doi: 10.5312/wjo.v14.i3.136
Inflammatory response in confirmed non-diabetic foot and ankle infections: A case series with normal inflammatory markers
Amr Hassan Ahmed, Shah Ahmed, Ahmed Barakat, Jitendra Mangwani, Helena White
Amr Hassan Ahmed, Shah Ahmed, Ahmed Barakat, Jitendra Mangwani, Department of Trauma and Orthopedics, Leicester University Hospitals-NHS Trust, Leicester LE1 5WW, Leicestershire, United Kingdom
Helena White, Department of Infectious Diseases and Tropical Medicine, Leicester Royal Infirm, Leicester LE1 5WW, Leicestershire, United Kingdom
Author contributions: Mangwani J and White H conceptualized the study design and aim; Ahmed AH and Ahmed S completed data collection and statistical analysis; Barakat A drafted the manuscript and reviewed it for final submission.
Institutional review board statement: This study was reviewed by the Leicester University Hospitals-NHS Trust research ethics committee. No ethical approval was required due to the de-identified anonymous retrospective nature of the published laboratory data.
Informed consent statement: There was no direct or even indirect contact between researchers and patients, with no necessity for "Signed Informed Consent Form" to carry out our study.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Ahmed Barakat, MBChB, MSc, Surgeon, Department of Trauma and Orthopedics, Leicester University Hospitals-NHS Trust, University Hospitals of Leicester Headquarters, Level 3, Balmoral Building, Leicester Royal Infirmary, Infirmary Square, Leicester LE1 5WW, Leicestershire, United Kingdom. ahmedharoonbarakat@gmail.com
Received: July 9, 2022
Peer-review started: July 9, 2022
First decision: September 26, 2022
Revised: October 23, 2022
Accepted: January 31, 2023
Article in press: January 31, 2023
Published online: March 18, 2023
Abstract
BACKGROUND

The distinction between foot and ankle wound healing complications as opposed to infection is crucial for the appropriate and efficacious allocation of antibiotic therapy. Multiple reports have focused on the diagnostic accuracy of different inflammatory markers, however, mainly in the diabetic population.

AIM

To evaluate the diagnostic accuracy of white cell count (WCC) and C-reactive protein (CRP) as diagnostic tools for this distinction in the non-diabetic cohort.

METHODS

Data was reviewed from a prospectively maintained Infectious Diseases Unit database of 216 patients admitted at Leicester University Hospitals–United Kingdom with musculoskeletal infections over the period between July 2014 and February 2020 (68 mo). All patients with confirmed diagnosis of diabetes were excluded while only those with confirmed microbiological or clinical diagnosis of foot or ankle infection were included in our study. For the included patients, we retrospectively retrieved the inflammatory markers (WCCs and CRP) at the time of presentation. Values of CRP 0-10 mg/L and WCC 4.0-11.0 × 109/L were considered normal.

RESULTS

After exclusion of patients with confirmed diabetes, 25 patients with confirmed foot or ankle infections were included. All infections were confirmed microbiologically with positive intra-operative culture results. 7 (28%) patients with osteomyelitis (OM) of the foot, 11 (44%) with OM of the ankle, 5 (20%) with ankle septic arthritis and 2 (8%) patients with post-surgical wound infection were identified. Previous bony surgery was identified in 13 (52%) patients, either a corrective osteotomy or an open reduction and internal fixation for a foot or ankle fracture with the infection developing on top of the existing metalwork. 21 (84%) patients did have raised inflammatory markers while 4 (16%) patients failed to mount an inflammatory response even with subsequent debridement and removal of metal work. CRP sensitivity was 84%, while WCC sensitivity was only 28%.

CONCLUSION

CRP has a relatively good sensitivity in the diagnosis of foot and ankle infections in non-diabetic patients, whereas WCC is a poor inflammatory marker in the detection of such cases. In presence of clinically high level of suspicion of foot or ankle infection, a normal CRP should not rule out the diagnosis of OM.

Keywords: Osteomyelitis, Septic arthritis, Surgical site infection, Inflammatory markers, C-reactive protein, White cell count

Core Tip: Distinction between foot and ankle wound healing complications as opposed to infection is crucial for appropriate and efficacious allocation of antibiotic therapy. Multiple reports have focused on diagnostic accuracy of different inflammatory markers, however, mainly in the diabetic population. Our aim was to evaluate the diagnostic accuracy of white cell count and C-reactive protein as diagnostic tools for this distinction in the non-diabetic cohort.