# Characteristics and management of systemic sclerosis-related osteomyelitis: a retrospective cohort study

## TL;DR

This study examines the characteristics and treatment of osteomyelitis in systemic sclerosis patients, finding that superficial swab cultures may be unreliable and prolonged antibiotic therapy may not be beneficial.

## Contribution

The study provides new insights into the management of systemic sclerosis-related osteomyelitis using a retrospective cohort analysis.

## Key findings

- Superficial swab cultures may not accurately identify the causative organisms of SRO.
- Prolonged antimicrobial therapy beyond six weeks does not significantly improve outcomes when local signs improve.
- Surgical intervention appears safe and effective for selected SRO patients.

## Abstract

Digital ulcers in patients with systemic sclerosis (SSc) can be complicated by SSc-related osteomyelitis (SRO). The microbiological data and optimal management of SRO remain unclear. This single-center retrospective study involved patients with SSc aged 18 or older from April 2005 to March 2022. Diagnosis of SRO was based on clinical presentation and MRI findings. The accuracy of the superficial swab culture results was estimated using the bone culture as a reference. Temporal changes in local signs for up to a year were collected, and their association with (1) duration of antimicrobial therapy (> 6 weeks) or (2) surgical interventions was assessed using univariable analyses. Among the 2,126 patients, 46 (2.2%) were diagnosed with SRO. In seven patients whose swab and bone cultures were both available, two (28.6%) had swab cultures identifying all the organisms detected in bone cultures. Resolution of local inflammatory signs consistently preceded wound closure. Three months after therapy initiation, prolonged antimicrobial therapy was not significantly associated with the resolution of local inflammatory signs (16/19 [84.2%] vs. 12/14 [85.7%]; P = 1.00), and surgical intervention was not significantly associated with wound dehiscence (6/9 [66.7%] vs. 20/24 [83.3%]; P = 0.36). Superficial swab cultures may not reliably reflect the true causative organism of SRO. Prolonging antimicrobial therapy beyond six weeks may be of little benefit for patients with SRO when local inflammatory signs improve. Surgical intervention may be a safe and effective option for selected patients with SRO.

The online version contains supplementary material available at 10.1007/s00296-025-05815-5.