Abstract
Septic arthritis is a potentially limb or life-threatening joint infection that requires prompt recognition and intervention to reduce morbidity and mortality. While intra-articular joint injections are commonly performed for osteoarthritis and other arthropathies, they carry a rare but significant risk of iatrogenic infection, particularly when performed in the presence of unrecognized joint or periarticular infection.
We report a case of a 52-year-old female with a history of traumatic brain injury and chronic right knee pain who developed severe knee swelling, pain, and systemic symptoms following an intra-articular corticosteroid injection performed without ultrasound evaluation/guidance. Post-procedure, she presented with fever, elevated inflammatory markers, and purulent knee effusion. Operative washout revealed a purulent tract extending from the knee joint capsule to the lateral thigh. Cultures from joint aspiration and intraoperative samples grew
This case highlights an unusual presentation of septic arthritis with extra-capsular extension likely due to iatrogenic needle tracking during joint injection. The causative organism,
Careful history, physical examination, and appropriate imaging are essential prior to joint interventions to avoid iatrogenic complications. This case illustrates the rare but serious risk of extra-capsular extension of septic arthritis following intra-articular injection and emphasizes the need for vigilance in identifying underlying infection before proceeding with invasive procedures.
Author Contributions
Copyright© 2025
Al-saeed Nawaf, et al.
License
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Introduction
Septic arthritis is a serious medical condition characterized by the infection of synovial fluid, primarily by bacteria. The incidence of septic arthritis ranges from 4-29 per 100,000 person-years with increased risk with advanced age, lower socioeconomic status, and immunosuppression Joint injections are a common procedure in the outpatient sport medicine and orthopedic setting. The procedure consists of injecting the targeted joint with both steroids and local anesthetic. The anesthetic often reduces post traumatic effect of injecting the joint and often acts as a short-term pain reliever until the steroids become effective. Steroids play a therapeutic role in reducing inflammation in the joint space and provide long lasting relief. To summarize, septic arthritis and joint injections are both important in the sports medicine setting. Septic arthritis is a serious joint infection requiring quick diagnosis and treatment to avoid possible complications. Joint injections, while generally safe, can have potential adverse effects, including the risk of introducing infection and it is critical to avoid joint injections during an active infection. Thus, careful consideration of the risks and benefits is necessary for both conditions, with ultrasound guidance being beneficial in both evaluation of the joint, as well as improving the safety and accuracy of joint injections. In this article, we discuss a case of a patient who had a complicated course of septic arthritis of the knee as a complication of an intra-articular injection performed without prior ultrasonography nor ultrasound guidance which may have prevented this undesired outcome. Thus, highlighting the importance of ultrasound utilization prior and during intra-articular joint injections.
Discussion
As was demonstrated in the case, the patient presented with an unusual clinical case of septic arthritis likely from The knee pain she described was likely due to the ongoing infection, however, due to the chronicity of knee pain in general, was treated as a non-infectious erosive disease such as osteoarthritis. Further history as well as prior ultrasound evaluation may have circumscribed the events that occurred leading to the extra-capsular spread of the disease. Interestingly, the sensation noted by the patient of the needle protruding through the knee and into her lateral thigh was the presumed introduction of the iatrogenic spread of the infection into the thigh. Looking into the literature, there seems to be benefit of utilization of ultrasound in the evaluation of septic arthritis.