23249              SEPTIC ARTHRITIS OF THE KNEE JOINT

This 65-year old man had a left medial meniscectomy at the age of 25. The knee remained symptomless until 9 months before his death when he suffered an infected lesion of his left foot secondary to trauma to that site. Eight weeks after this episode he developed an effusion in his left knee associated with elevated temperature and throbbing of the knee. Later a fluctuant mass appeared over his upper tibia forming a sinus about 2.5 cms below the tibial tuberosity. The infection only partially responded to lincomycin. His death was due to an unrelated illness - myocardial infarction with cardiac standstill.

The specimen shows a longitudinal section of the left knee joint. The joint space is involved by the suppurative process, fibrosis has occurred in parts of the joint space, The whole of the space being replaced and destroyed. There is osteomyelitis of the upper end of the tibia particularly in the subarticular region with three connecting pockets of pus above this, in the medulla. There is extensive subperiosteal involvement along the posterior shaft of the tibia - the process extending from here into the joint cavity.