Trauma-Induced Septic Arthritis of the Knee in an Immunocompetent Young Patient: A Case Report

Introduction

Clostridium cadaveris, initially identified in the late 19th century as a bacterium associated with human decomposition [1], is a gram-positive bacillus formerly referred to as Clostridium capitovale. This non-pathogenic telluric germ is commonly found in the human digestive tract. While several documented cases of infections by Clostridium cadaveris have been linked to gut-related sources [2,3], these occurrences are predominantly observed in immunosuppressed individuals [4–7]. Although osteoarticular infections resulting from trauma with wound exposure to environmental bacteria have been documented [8–10], there is no previous record in the literature of septic arthritis specifically caused by direct inoculation of Clostridium cadaveris.

This report describes an immunocompetent 11-year-old boy with septic arthritis due to Clostridium cadaveris following an accidental knee injury. The main aim of this case report is to highlight the importance of rapid diagnosis of the cause in septic arthritis, particularly in children, to ensure that appropriate treatment can begin to prevent joint and tissue damage. It contributes to the existing literature, emphasizes the potential association between soft tissues traumatology and Clostridium cadaveris septic arthritis, and discusses the pertinent management strategies.

Case Report

An 11-year-old boy, with no significant medical history or known allergies, was brought to the emergency room (ER) after sustaining a soft tissue injury on the knee. He presented with pain, sweating, and emesis symptoms. The previous day, he had knelt on a rusty nail while engaged in gardening activities.

According to the patient’s account, the nail entered the right knee joint through the anteromedial side and spontaneously exited when he stood up. The initial medical assessment comprised X-ray imaging to rule out any potential fractures and an ultrasound examination (US) to identify any foreign bodies in the joint. The ultrasound revealed no signs of fracture, joint effusion, or foreign body (Figure 1). A Tetanus Rapid Diagnostic Test using the Exalto Tetanus kit (Biosynex®, France) was conducted and returned a negative result. In the initial phase of care, no biological testing was performed and the emergency physician decided to perform catch-up vaccination and administration of specific antitetanic immunoglobulins to ensure tetanus immunity. He added a 7-day course of oral Amoxicillin-Clavulanate to address local cellulitis, with no immediate consultation with a pediatric orthopedic specialist. The patient had been discharged with painkiller treatment and no immobilization several hours after his arrival.

Two days after the initial ER visit, the patient’s condition significantly deteriorated. He returned to the ER. He had developed a high fever, a stiff knee with flexion contracture, and a considerable joint effusion. The patient exhibited marked systemic inflammation, with a C-reactive protein (CRP) level of 95 mg/dL and hyperleukocytosis of 12.2 giga/L. A follow-up X-ray revealed the presence of visible joint effusion (Figure 2). In response to the worsening clinical condition, a decision was made to proceed with surgical intervention. Arthrocentesis was performed, during which purulent joint fluid was aspirated (Figure 3). In the same procedure, conversion to an open arthrotomy approach for the joint debridement, and a 14CH drain was placed to facilitate drainage for 48 hours. Three bacteriologic samples were collected during this procedure. Postoperatively, the patient was initiated on intravenous Piperacillin-Tazobactam at a dose of 4000 mg 3 times a day.

From the bacteriologic samples obtained, no organisms were seen with Gram stain, and 1 out of the 3 long-incubation cultures identified a Clostridium species. Despite partial improvement in knee pain, the patient continued to exhibit a stiff and inflamed knee joint, and his CRP levels increased to 108 mg/dL. An MRI performed 5 days postoperatively revealed persistent significant joint effusion and extensive synovitis (Figure 4).

In light of these findings, a decision was made to conduct a second joint debridement by arthrotomy, and a new 14CH drain was placed for an additional 48 hours. Notably, blood cultures remained sterile, and the identification of the knee fluid samples using MALDI-TOF technology confirmed the presence of Clostridium cadaveris. Based on the results of the initial articular debridement samples, the patient’s treatment plan was adjusted. He was subsequently administered intravenous Cefepim at a dose of 2000 mg 3 times a day in combination with Daptomycin at a daily dose of 500 mg.

Following an initial elevation of the inflammatory markers, with CRP levels up to 143 mg/dL and recurrent episodes of high fever and night shivers, the patient’s clinical course gradually improved. The good evolution was attributed to 2 surgical debridements combined with intravenous administration of adapted antibiotics. CRP levels decreased to 61 mg/dL and the white cell count decreased to 6.1 G/L by the time of discharge. A transition to oral antibiotics was initiated, with Clindamycin at a dosage of 600 mg 3 times a day for a 3-week course, based on the results of the antibiotic susceptibility test (Table 1). On the day of discharge, the knee was dry, and mobility was satisfactory with the assistance of crutches. The surgical scar was clean and dry.

During a follow-up visit 1 week later, the wound remained clean, and the patient was in good general health. Inflammatory markers had returned to nearly normal levels, with a CRP of 12 mg/dL, and a follow-up X-ray revealed no evidence of joint effusion.

A specialized consultation in the Immunology Department, requested upon discharge, did not reveal any clinical or biological immune deficiencies. One month following the initial management, the patient had normal knee mobility, with no complaints of stiffness or pain, and inflammatory markers and white cell count had normalized (CRP <5 mg/dL).

The patient was discharged from our pediatric hospital care after a 2-week hospitalization. A clinical and radiological follow-up plan was established, with a 1-year duration, to monitor the knee joint’s condition and ensure no deterioration. At the latest visit, 8.5 months after initial treatment, the patient has returned to a normal life and the X-ray examination showed no signs of osteoarthritis or osteochondral damage.

Discussion

This case of Clostridium cadaveris-induced septic knee arthritis in an immunocompetent young patient following a traumatic injury with a rusty nail serves as an important clinical example. It underscores the importance of considering unusual pathogens in patients with joint infections, especially in unusual cases, involving traumatic inoculation.

To our knowledge, no case of direct inoculation septic arthritis by Clostridium cadaveris has been described in the literature. Pediatric osteomyelitis and septic arthritis are mostly due to hematogenous spread [11,12] and can result in severe sequelae in a non-mature skeleton [13].

More than 30 cases of clostridial joint infection have been described in the past [9] and Corrigan et al described the only known case of chronic Clostridium cadaveris tibial infection, in a 32-year-old immunocompetent person [14]. Even though both patients were immunocompetent and the entry point for infection is direct trauma with the ground, our case differs on several parameters as the duration of the infection, the infection site, and the total duration of antibiotic therapy chosen.

The successful management of this case, involving surgical debridement, antibiotic therapy, and follow-up care, emphasizes the importance of a multidisciplinary approach in addressing complex osteoarticular infections. However, our management was challenged by the initial outpatient care, which involved probabilistic antibiotic treatment. The initial blood cultures and bacteriological samples were stripped by the probabilistic antibiotic therapy started on the day of the first visit to the Emergency Department. Consequently, it prevented the identification of potential polymicrobial infections.

In accordance with guidelines from the French health institute (Haute Autorité de Santé), all currently available antitetanic vaccines operate based on a Clostridium tetani antitoxin mechanism [15]. It is reasonable to assume that an up-to-date vaccination schedule would not impact the presence of Clostridium cadaveris in cultures, as this bacterium is non-toxigenic. Additionally, the patient’ outdated vaccination schedule did not appear to act as an immunosuppressive factor.

Surgical management of the patient consisted of arthrocentesis with arthrotomy, followed by a second direct arthrotomy joint debridement. While the treatment of septic arthritis in adult native joints is well-established [16], there is a lack of literature on the pediatric population. A recent systematic review by Donders et al [17] demonstrated the lower risk of additional drainage procedures and acceptable clinical outcomes in arthroscopy as compared with arthrocentesis and arthrotomy for knee septic arthritis in children. Although knee arthroscopy in young patients is an accepted procedure [18], it requires a high level of experience, and only 1 out of 4 senior surgeons of our center was able to perform a knee arthroscopy. According to our local guidelines, our preference is to perform double-needle drainage, consisting of 2 parapatellar internal and external punctures to create a washing flow route. The 2-needle drainage prevents joint stiffness better than arthrotomy [19].

Conclusions

This case report highlights the rare diagnosis of knee arthritis with Clostridium cadaveris by direct inoculation, expands our understanding of acute joint infections, and underscores the need for vigilance in diagnosis and early management of cases with atypical presentations, particularly in children, to prevent untreatable osteoarticular damage.