Infection in orthopaedic and trauma surgery: clinical and microbiological analysis of primary infections in our centre during 2024–2025

A. Lajara, M. González, L. de la Cruz, J. M. Viloria, M. Martín, E. Esparcia, I. Ramos, E. Vico, C. Lozano
Department of Orthopaedic Surgery and Traumatology, León University Care Complex, León, Spain

KEY FIGURES
- 33 infection episodes
- 31 patients
- 61.4 mean age, years (16–93)
- 81.8% underwent debridement

01. INTRODUCTION
Primary orthopaedic infections include septic arthritis, osteomyelitis, bursitis and complicated cellulitis, with a relevant impact on the clinical course and on the need for surgical treatment. The aim of this study was to describe the clinical, microbiological and therapeutic characteristics of a cohort of patients with primary infection.

02. MATERIALS & METHODS
Retrospective observational study of 33 primary infection episodes occurring in 31 patients. Demographic data, location, infection type, comorbidities, clinical and laboratory findings, microbiology and treatment strategies were analysed.

03. COHORT
- Sex: 23 male, 10 female
- Mean age: 61.4 years (range 16–93)
- Active smokers: 3
- Diabetes mellitus: 5
- ASA grade: I 4, II 12, III 10, unknown 7
- Hospital admissions: mean 1.0 (range 1–2)

04. CLINICAL PRESENTATION
- Local inflammatory signs: 32 (97.0%)
- Fistula / dehiscence: 10 (30.3%)
- Fever or T >37 °C: 9 (27.3%)
- Sepsis criteria: 1 (3.0%)

05. LABORATORY FINDINGS (on admission)
- White cell count: mean 10,061, SD 4,483
- Neutrophils, %: mean 73.4, SD 15.1
- C-reactive protein: mean 93.7, SD 95.6
- Glucose: mean 107.7, SD 40.0

06. ANATOMICAL LOCATION (n = 33 episodes)
- Knee: 12 (36.4%)
- Elbow: 6 (18.2%)
- Forearm: 3 (9.1%)
- Pelvis / pubis: 2 (6.1%)
- Tibia / fibula: 2 (6.1%)
- Hand / wrist: 2 (6.1%)
- Shoulder / humerus: 2 (6.1%)
- Thigh / femur: 2 (6.1%)
- Hip: 1 (3.0%)
- Foot / ankle: 1 (3.0%)

07. TYPE OF PRIMARY INFECTION (n = 33 episodes)
- Septic arthritis: 12 (36.4%)
- Osteomyelitis: 11 (33.3%)
- Bursitis / cellulitis: 6 (18.2%)
- Soft-tissue infection: 3 (9.1%)
- Other: 1 (3.0%)

08. MICROBIOLOGICAL PATTERN (n = 33 episodes)
- Monomicrobial: 19 (57.6%)
- Culture-negative: 8 (24.2%)
- No data available: 4 (12.1%)
- Polymicrobial: 2 (6.1%)

09. LEADING PATHOGENS (isolates in 33 episodes)
- MSSA: 4 (12.1%)
- MRSA: 2 (6.1%)
- P. aeruginosa: 2 (6.1%)
- S. epidermidis: 2 (6.1%)
- E. coli: 2 (6.1%)
- 7 further species: 1 (3.0%)

10. MANAGEMENT (n = 33 episodes)
- Lavage & debridement: 27 (81.8%)
- Conservative treatment: 3 (9.1%)
- Unknown: 3 (9.1%)
Intraoperative samples were taken in 23 episodes, with a mean of 3.4 samples per episode (median 3).

11. CONCLUSIONS
1. Infections mainly involved the knee and elbow — together 54.6% of episodes.
2. Septic arthritis and osteomyelitis predominated, representing 69.7% of the cohort.
3. Presentation was essentially local: 97.0% local signs, one patient with sepsis.
4. Lavage and debridement predominated (81.8%); a 24.2% culture-negative rate underlines the value of adequate intraoperative sampling.

CITED LITERATURE
1. Mathews CJ, Weston VC, Jones A, Field M, Coakley G. Bacterial septic arthritis in adults. Lancet. 2010;375(9717):846–855.
2. Lew DP, Waldvogel FA. Osteomyelitis. Lancet. 2004;364(9431):369–379.
3. Ross JJ. Septic arthritis of native joints. Infect Dis Clin North Am. 2017;31(2):203–218.
4. Metsemakers WJ, Morgenstern M, McNally MA, et al. Fracture-related infection: a consensus on definition from an international expert group. Injury. 2018;49(3):505–510.