Septic arthritis of the knee following intraarticular injections in elderly patients: report of six patients.

BACKGROUND Intraarticular injections for the local treatment of osteoarthritis are widely used in the office or hospital setting. Septic arthritis is a potential catastrophic complication of intraarticular injection, as bacterial arthritis of any cause is associated with up to 15% mortality and residual impairment of joint function in up to 50% of survivors. There is lack of evidence regarding the precautions that should be taken to avoid such a complication, as well as how often it is encountered. OBJECTIVES To report our experience with the clinical presentation, diagnosis and treatment of knee septic arthritis following intraarticular injections. METHODS We followed six patients who were admitted to the hospital and underwent surgery for the treatment of pyogenic arthritis following injection to the knee joint in outpatient clinics. RESULTS All but one patient were over 70 years old with comorbidities. Three patients were injected with steroid preparations and three with hyaluronic acid several days before admission. In all six patients the infection was treated surgically and three of them had undergone more than one operation during their hospitalization. Four of the six patients were treated by means of an open arthrotomy and synovectomy, and the other two were treated successfully with arthroscopic lavage and synovectomy. One patient underwent an above-knee amputation due to septic shock and died after several days. CONCLUSIONS Despite the rarity of this complication, surgeons must be aware of the possibility of pyogenic arthritis when administering injections, especially in elderly patients with serious underlying medical conditions.