Microbiological profile of septic arthritis in adults: Lessons learnt and treatment strategies

The aim of this study is to characterise the clinical and microbiological profile of adult patients treated at our orthopaedic unit with septic arthritic between 2006 and 2017.

A total of 70 patients who were admitted with a diagnosis of septic arthritis between 2006 and 2017 were included in the study. The patients' clinical and epidemiological characteristics were surveyed; microbiological profile and the complications relating to the patients' treatment were identified.

Septic arthritis was more common among males (83%). About 75% of the patients presented with a history of fever. The knee was the most commonly affected joint (71%), followed by the hip. While C-reactive protein was found to be consistently >75, total blood white blood cell (WBC) counts were found not to be reflective of the presence of infection with a mean WBC count of only 13,561/cu.mm, and Gram stain examination had a poor sensitivity of 47%. Among the co-morbidities, the most prevalent association was with diabetes mellitus. The infectious agent most frequently isolated was Staphylococcus aureus(42.85%). The antibiotic sensitivity pattern has evolved since the early years, with resistant strains becoming increasingly prevalent. Unusually, high incidence of streptococci was noted (30%), contrary to the published literature. One-third of the patients had multi-resistant organisms. Septic arthritis left 70% of the patients with a significant residual disability at 6 months follow-up and had 4.25% mortality.

Changing sensitivity patterns of microbes in septic arthritis point to a need for reconsidering empirical antibiotic therapy. Joint damage following infection can lead to significant disability.