Bilateral septic knee arthritis after treatment of an ectopic pregnancy with methotrexate.

We describe a case of bilateral septic knee arthritis that followed the administration of methotrexate for nonsurgical termination of an ectopic pregnancy. We believe that methotrexate is a relatively effective alternative to surgery in patients with early unruptured tubal pregnancies, but suggest that it be used with caution in view of possible septic events.