Abram SGF, et al. - Researchers investigated the risk of mortality and adverse joint outcomes following septic arthritis of the native knee via retrospectively studying a cohort of 12,132 patients [mean age: 56·6 years [SD 24·9]; 4,307 (36%) female] who received arthroscopic knee washout for septic arthritis in England between April 1, 1997, and March 31, 2017, using data in the national Hospital Episode Statistics database. Septic arthritis was the primary admitting diagnosis in 10,195 (84%) patients; among these, 90-day mortality was 7·05%; this rose to 22·69% in 1,842 patients older than 79 years. Secondary septic arthritis diagnosis vs primary diagnosis was associated with an adjusted odds ratio for mortality of 2·10. Among 11,393 patients with at least 1-year follow-up, the 1-year rates were 0·13% for arthrodesis, 0·40% for amputation, and 1·33% for arthroplasty. Within 15 years, 159 of 1,816 patients reported receiving of arthroplasty, corresponding to an annual risk of arthroplasty that was about six times that of the general population. Findings suggest serious consequences of septic knee arthritis in patients undergoing arthroscopic knee washout and highlight the potentially disastrous outcomes linked with sepsis from musculoskeletal joint infection.