Management of a necrotizing soft tissue injury post TKA using NPWT with microbial irrigation for limb salvation

Statement of Clinical Problem:   A 64yo male had a left total knee arthroplasty on 3/23/15.  The incision had blistering at discharge.  The patient developed a necrotic soft tissue infection and was subsequently admitted to the hospital for incision and drainage.  Risk for amputation was discussed with patient by orthopedics.

Description of Past Management:   Post- op, the incision was dressed with hydrofiber with silver POD3.  Blistering developed, changed treatment to contact layer with absorbent pads.  At 6 weeks post op incision measured:  14.1cm x 9cm x 2.5cm with undermining from 2-9 o’clock up to 2.8cm with tendon and bone exposure. Initial debridement on 5/13/15 with cultures showed S. aureous, enterococcus, and acinetobacter. The plan was changed to NPWT and aggressive IV antibiotic therapy.  Wound measurement after debridement was 17cm x 11cm x 5cm.

Current Clinical Approach: Patient returned to OR for further debridement and antibiotic spacer placement on 5/18/15.  Cultures still positive for enterococcus and ralstonia pickettii.  After WOC nurse consult, plan changed to NPWT with antimicrobial irrigation.  A broad spectrum NPWT antimicrobial solution was used.  Initial settings were: 100mL infusion with 10 min dwell every 2 hours.  Pressure setting at 150mmHg.  After two weeks of therapy, patient was transported to tertiary care facility for flap and hardware salvage/removal.  Wound measured 16.5cm x 9cm x 2cm.  

Patient Outcomes:  Limb salvage was achieved with use of NPWT with irrigation as part of multidisciplinary plan of care.  Patient transferred to tertiary hospital where joint removal and flap were performed.  Patient is ambulatory with brace and plans for new TKA in future. 

Conclusions:  Use of NPWT with microbial irrigation can aid in limb salvage with necrotizing soft tissue infection when used in conjunction with antibiotic therapy and/or serial debridement.