2 months of dislocated Knee repalcement in an elderly lady with high BMI

Allleged history of fall 2 months back. Knee lying dislocated when reviewed by usTKR done 5 years ago with no issues till the fall Bloods and knee  aspiration - -  normal Options of RHKif frozen section was negative or  Fusion if infected was discussed. 2 stage was ruled out by patientThe decision had to be one stage and no external fixation as per patients families request . So a fusion was done as frozen section showed probable infection as per fieldman's criteria, Survived the surgery  and mobilised FWB day 2 day before discharge went into renal shutdown at day 12  and after a month of ICU and   stay we lost her