Acute Haematogenous Revision Total Knee Arthroplasty Infection by Streptococcus canis Treated by Debridement, Antibiotics, and Implant Retention: A Case Report.

Prosthetic joint infections (PJIs) are one of the most feared complications by orthopaedic surgeons. Haematogenous PJI represents an important part of PJI cases. Streptococcus canis is an extremely rare cause of haematogenous PJI and its medical and surgical treatment and prognosis are not well established. We present a 79-year-old female patient who had a revision total knee arthroplasty (rTKA) surgery three years before. She was admitted to the hospital referring to three days of knee pain, restricted range of motion, and fever. Blood tests demonstrated leukocyte and C-reactive protein elevation. Joint fluid aspiration showed elevated white blood cell count with a high neutrophil differential and its conventional culture was positive for Streptococcus canis. She did not have pets but she took care of her daughter's dog. An acute haematogenous infection of the rTKA was diagnosed and treated with debridement, antibiotics (eight weeks of IV ceftriaxone), and implant retention (DAIR). After one year, the patient remains clinically asymptomatic without changes on X-rays and with normal serum levels of inflammatory blood markers. Streptococcus canis has to be kept in mind as a possible cause of haematogenous TKA infection in patients who have contact with domestic pets and patients should be asked for this contact. We recommend DAIR as a viable treatment option for this type of infection, which may show excellent results.

Fractura avulsión tipo sleeve de la patela / Patella sleeve avulsion fracture

Introducción: la fractura avulsión tipo sleeve o en manguito es una lesión rara que puede afectar a la patela durante la etapa de crecimiento infantil. Su diagnóstico precoz es clave para obtener un buen resultado clínico y funcional y evitar secuelas derivadas de la lesión. El diagnóstico diferencial se realiza con el síndrome de Sinding-Larsen-Johansson y la fractura del polo inferior de la rótula. Caso clínico: presentamos el caso de un varón de 12 años, sin antecedentes de interés, que acude a urgencias refiriendo gonalgia derecha tras mal movimiento mientras corría. El paciente es dado de alta orientándose como una tendinitis rotuliana. Dos semanas más tarde acude con dolor e impotencia funcional completa para la extensión de rodilla derecha tras caída de nuevo en ámbito deportivo. En la imagen de la radiografía convencional se observa una avulsión osteocondral desplazada del polo inferior de la patela, tipo sleeve. Dada la limitación funcional, se decide intervención quirúrgica mediante reinserción del polo inferior patelar mediante sutura tipo Krackow y puntos transóseos. Conclusiones: la fractura tipo sleeve es poco frecuente y puede pasar desapercibida. El mecanismo lesivo (indirecto por tracción), los antecedentes de dolor previo y las imágenes de radiología convencional deben aportar un alto nivel de sospecha y disminuir el infradiagnóstico de esta entidad para así evitar las secuelas derivadas como la patela alta, el dolor anterior de rodilla persistente o la pérdida de fuerza del cuádriceps (AU)

Introduction: the patella sleeve fracture is a rare injury that can affect the patella during the infant growth stage. Its early diagnosis is important to obtain a good clinical and functional result and to avoid sequelae derived from the injury. Differential diagnosis is made with Sinding-Larsen-Johansson syndrome and the fracture of the lower pole of the patella.Clinical Case: we present the case of a 12-year-old male, with no history of interest, who came to the emergency room reporting right knee pain after making a bad movement while running. The patient is discharged oriented as patellar tendonitis. Two weeks later, he returned with pain and complete functional impotence to extend his right knee after falling again doing sport. In the conventional X-ray image, a displaced osteochondral avulsion of the lower pole of the patella, 'sleeve' type, is observed. Because of the functional limitation, surgical intervention was decided doing reinsertion of the lower patellar pole using Krakow suture and transosseous stitches.Conclusions: patella sleeve type fracture is rare and may go unnoticed. The lesion mechanism (indirect by traction), the history of previous pain and conventional radiology images should provide a high level of suspicion and reduce underdiagnosis of this entity and thus avoid derived sequelae such as patella alta, anterior knee pain or loss of quadriceps strength. (AU)