Atypical mycobacterium infection following anterior cruciate ligament reconstruction

A man in his 20s presented with instability of the right knee following an incident of fall from a height. He was clinicoradiologically diagnosed to have an anterior cruciate ligament (ACL) tear for which he underwent ACL reconstruction. Postoperatively, he was started on an accelerated ACL rehabilitation protocol. Six weeks postoperatively, he developed features of subclinical septic arthritis for which he underwent arthroscopic debridement. Intraoperative samples cultured Mycobacterium abscessus complex on MGIT 960 system. The patient subsequently had to undergo another debridement after 1 month as there were clinical signs of persisting infection. The graft was intact even on the second debridement and after removing the implants. This case reports a rare complication of ACL reconstruction with infection by atypical mycobacterium and the clinical outcome. It also emphasises that prompt surgical intervention can save the graft.