Synovial fistula of the knee: a complication of arthroscopy.

The occurrence of a synovial fistula after knee arthroscopy is uncommon. In a retrospective review of 976 arthroscopies of the knee over 3 years, six patients developed synovial fistulae (incidence 6.1/1,000). All patients were treated with short-term immobilization and oral prophylactic antibiotics. All fistulae closed after an average of 9 days of immobilization, and none required further treatment. Risk factors that may predispose a patient to fistula formation are posterior compartment portals and the presence of significant degenerative joint disease. A treatment protocol is presented.