Treatment of Septic Arthritis of the Hip Joint Using Repeated Aspirations: When Should We Operate?

Background The well-accepted treatment of septic arthritis of the hip joint (SAHJ) is surgical drainage of the joint, but repeated aspirations of the hip joint under sonography, have been used for over twenty years with significant success in some centers, including ours. In recent years, we identified some children who did not respond to aspirations and had to undergo arthrotomies. We were concerned that some children may have reached the operating room after a longer than ideal time. Objective Identification of the characteristics of patients who did not respond to repeated aspirations and development of a treatment algorithm that expedites decision-making regarding the necessity of surgery. Methods This is a single-center retrospective cohort analysis. All the patients diagnosed with SAHJ between 2007 and 2019 were identified. Patients who responded to repeated aspirations were compared to those who did not improve and required surgery. Demographic and clinical data and laboratory results were obtained from the patients' electronic medical records. Results Forty-eight children (88.9%) were treated successfully with repeated aspirations and six children (11.1%) did not improve after aspirations and underwent hip arthrotomies. Five out of 48 children from the aspiration group (10.4%) and 4 out of 6 from the arthrotomy group (66.7%) had chronic comorbidities (p = 0.0051). The mean duration of fever over 38.5 degrees centigrade and the length of stay were higher in the arthrotomy group (p = 0.0040, p = 0.0301, respectively). When we examined the change in C-reactive protein (CRP) levels before and after the first aspiration (Delta CRP), we found a decrease in the aspiration group and an increase in the arthrotomy group (p = 0.0044). Conclusion The new algorithm which we present allows an expeditious assessment of the patient's response to the repeated aspiration method and thus prevents unnecessary surgeries for the treatment of SAHJ. Patients with chronic comorbidities, prolonged fever, and an increase in CRP level following the first aspiration, are at risk of treatment failure and should be treated with an arthrotomy.