[Role of arthroscopy in the treatment of pyogenic arthritis of the knee in adults. Report of 16 cases].

PURPOSE OF THE STUDY: The goal of this study was to determine the place and the limit of the arthroscopic management of septic knee arthritis. This procedure is an alternative treatment to needle aspiration and to open arthrotomy drainage.

MATERIAL AND METHODS: Sixteen adult patients were treated between 1993 and 1997 for pyogenic septic arthritis of the knee. The duration of symptoms prior to arthroscopic debridement was 4.5 days (range, one to 14 days). In 8 patients the infection was hematogenous. 5 patients had post-operative infection, 2 had post-traumatic infection and one infection followed an intraarticular injection. All the patients were treated by arthroscopic debridement and irrigation of the knee. A partial synovectomy of the anterior compartment was carried out in 4 cases in which the infection diagnosis was delayed. In 6 patients with resistant germ or early unfavorable course (clinically or biologically), an early iterative arthroscopy was performed between 2 and 7 days after the first procedure. The medical treatment consisted in a double systemic antibiotherapy for an average duration of 4 weeks, followed by oral treatment for 3 weeks. The patients were encouraged to mobilize their knee as soon as C Reactiv Protein was normal (average 3 weeks, 0 to 12).

RESULTS: The average follow up was 20.5 months (2 to 60). Two elderly patients died, one directly related to knee infection. One patient with prior patella osteosynthesis had a recurrent infection 10 months after the arthroscopy. Thirteen out of 14 patients had an excellent or good functional result.

DISCUSSION: Arthroscopic drainage is a valuable alternative procedure for the treatment of the septic arthritis. Arthroscopic treatment leads to a more effective infectious result than needle aspiration procedure and the functional result is better than with open drainage. Septic arthritis in the elderly or in patients with multiple organ failure have a poor prognosis. The treatment of pyoarthrosis of the knee must be aggressive and we frequently propose an iterative arthroscopic drainage, specially in case of delayed treatment, early unfavorable course or multiresistant germ.