Tidal irrigation in septic arthritis of the knee: a potential alternative to surgical drainage

To evaluate the efficacy of tidal irrigation (TI: repeated distention and irrigation of joint with saline under local anesthesia through 14 gauge Vere's needle) as a method to effect drainage in septic arthritis of the knee.

Eleven episodes of septic arthritis of the knee in 10 patients were approached with TI when drainage of purulent material could no longer be satisfactorily accomplished with repeated arthrocenteses. Clinical and synovial fluid (SF) data were systematically collected and analyzed.

Four out of 11 episodes resolved without resorting to further surgical drainage. Cases responding to TI involved significantly older patients with lower volume effusions at presentation. Cases not responding to TI more frequently involved gram negative infection (3/7 cases vs 0/4). Variables of SF obtained preceding and following the first TI predicted outcome, with 3/4 responding cases demonstrating both a drop in white blood cell count of > or = 25% and a decrement of > or = 50% in volume while none of the cases eventually requiring surgery responded in this fashion (p < 0.05).

TI can potentially supplant conventional surgical drainage in some cases of septic knee arthritis that do not respond to medical management.