The significance of the bacterial agent in pyogenic flexor tenosynovitis – a retrospective case study of 102 patients

Abstract

Introduction: Pyogenic flexor tenosynovitis is an infection of the flexor tendon sheath in the finger, usually appearing after a puncture wound. The diagnosis is established by the Kanavel’s signs being present. They include tenderness along the tendon sheath, fixed flexor position of the finger, pain when extending the finger and a fusiform swelling of the finger. The treatment consists of intravenous antibiotics, surgical treatment, and postoperative oral antibiotics. Swabs for bacterial culture are taken at the surgical site. Physiotherapy is in most cases needed for the patient to recover. Aim: Since long-term complications to this infection may limit a patient’s hand function, and in some cases work-life, this study investigates whether the type of bacteria influences the outcome of pyogenic flexor tenosynovitis in regard to number of surgical irrigations, the duration of treatment with antibiotics, the amount of physiotherapy appointments and the amount of follow-up operations. Secondarily this study also investigates whether patients treated for pyogenic flexor tenosynovitis regain full function in the treated finger. Methods: A retrospective study was conducted by collecting the information of patients operated with surgical irrigation of pyogenic flexor tenosynovitis, from patient’s journals from the year 2010 to 2020. Additionally, a survey was constructed to investigate the patient’s perceptions of the long-term results after treatment for pyogenic flexor tenosynovitis. Results: The bacterial cultures found in the 102 patients’ journals were: Staphylococcus aureus, beta-hemolytic Streptococci, Pasturella Multocida, Coinfection with Staphylococcus aureus and beta-hemolytic Streptococci, negative culture and 8% of the group were affected 3 by other less common bacteria. The three largest groups were the one with a negative culture, and the ones affected by Staphylococcus aureus and beta-hemolytic Streptococci. Therefore, it was decided to compare these three groups to each other. Beta-hemolytic Streptococci showed to cause a more potent infection with increased C Reactive protein level and that required longer intravenous and per oral antibiotic treatment. The negative culture patient group disclosed an infection with significantly lower C-reactive protein, shorter required intravenous and per oral antibiotic treatment duration compared to the other groups; Staphyloccus aureus and beta-hemolytic Streptococci. The functional outcome that was assessed by the survey, revealed that the worst outcome was in the case of beta-hemolytic Streptococci, and the best functional outcome was seen in the patient group presented by negative culture. Conclusion: The most favorable outcome after treated pyogenic flexor tenosynovitis was found in the negative culture patient group. We suggest that may be due to a less fulminant infection, leading to reduced manipulation during treatment, and therefore leading to a more promising outcome. The patient group with the worst outcome in our research was affected by beta- hemolytic Streptococci, suggesting that this bacterium causes a rapidly progressing infection.