[External synovial fistula of the infrapatellar bursa following arthroscopic meniscus resection. A clinical case report and topographic-anatomic study].

Following arthroscopic meniscectomy a 41-year old patient developed an external synovial fistula in the area of the central joint approach with a communication to the deep intrapatellar bursa. Anatomical preparations performed on 20 knee joints revealed extraordinary variations in the dimension of the infrapatellar bursa with a mean longitudinal diameter of 24 mm and a transversal diameter of 38 mm. The distance between bursa and the distal margin of the patella measured 15 to 39 mm. These topographic conditions lead to the assumption that the bursa is exposed to iatrogenic lesion by placing a central joint approach. Therefore a proximal incision is recommended for the central portal to avoid a lesion of the bursa with the potential risk of a postoperative fistula formation.