case_images: PMC8251103_01
case_images: (a) Post-operative TKA X-ray, (b) skin necrosis on the 18th post-operative day, and
  (c) surgical wound immediately after debridement and antibiotics with implant
  retention (DAIR).
case_images: jbji-6-235-g01.jpg
case_images: PMC8251103_01_jbji-6-235-g01.jpg
case_images: Ch1.F1
case_images: A 78-year-old woman, with a history of atrial fibrillation and hypertension, underwent left TKA for primary osteoarthritis (Fig. 1a). On the 18th post-operative day, a significant wound skin necrosis was found with slight concurrent wound leakage (Fig. 1b), and despite C-reactive protein (CRP) levels of 15.8 mg L, there was a high suspicion of an underlying acute periprosthetic joint infection. The patient was switched back to enoxaparin and was scheduled for surgery within 2 d (Fig. 1c).
case_images: (a) Skin necrosis on the fifth day after DAIR, (b) X-ray after the implant
  removal and application of an antibiotic-loaded cement spacer, and (c) medial
  gastrocnemius muscle flap for wound coverage.
case_images: jbji-6-235-g02.jpg
case_images: PMC8251103_01_jbji-6-235-g02.jpg
case_images: Ch1.F2
case_images: Despite these efforts, skin necrosis progressed on the distal part of the wound (Fig. 2a). On the fifth day after DAIR, skin necrosis at the distal part of the wound progressed (Fig. 2a), and a decision was made to remove the prosthesis and implant an antibiotic-loaded handmade mobile spacer (with 4 g vancomycin and 2 g meropenem per bag of bone cement) and perform a medial gastrocnemius muscle flap for wound coverage (Fig. 2b-c).
case_images: (a-d) Skin necrosis progression after TKA revision, extending to the
  lower leg around the incision made to harvest the muscle flap.
case_images: jbji-6-235-g03.jpg
case_images: PMC8251103_01_jbji-6-235-g03.jpg
case_images: Ch1.F3
case_images: During the next weeks, an extensive superficial skin necrosis developed around the knee, extending to the lower leg around the incision made to harvest the muscle flap (Fig. 3).
case_images: (a) A period of 3 weeks after revision surgery, new debridement of all necrotic
  areas, interruption of enoxaparin, negative pressure dressings, and
  hyperbaric oxygen chamber treatment were performed. (b-c) Progressive healing of the wound.
  (d) New debridement. (e) Split-thickness skin graft of the thigh for wound
  coverage.
case_images: jbji-6-235-g04.jpg
case_images: PMC8251103_01_jbji-6-235-g04.jpg
case_images: Ch1.F4
case_images: Necrosis stopped progressing (Fig. 4a-d), and eventually a split-thickness skin graft of the thigh for wound coverage was performed (Fig. 4e).
case_images: (a-d) Lateral leg wound evolution and (e-h) response after institution of a
  2-week course of oral amoxicillin-clavulanate.
case_images: jbji-6-235-g05.jpg
case_images: PMC8251103_01_jbji-6-235-g05.jpg
case_images: Ch1.F5
case_images: A few weeks after hospital discharge, an ulcer on the lateral aspect of the leg (unrelated to previous incisions) developed and progressed (Fig. 5a-d). A biopsy was again performed that revealed unspecific findings, suggesting an infected venous leg ulcer, and a 2-week course of oral amoxicillin-clavulanate was instituted with excellent clinical response (Fig. 5e-h).
case_images: (a) Skin before the second-stage surgery, (b) post-operative X-ray, (c) skin fully
  healed, (d1-d2) left knee range of motion in the last evaluation,
  0-115.
case_images: jbji-6-235-g06.jpg
case_images: PMC8251103_01_jbji-6-235-g06.jpg
case_images: Ch1.F6
case_images: Second-stage surgery was consecutively postponed, but when satisfactory soft tissues were present (Fig. 6a) and after an adequate discussion with the patient, a decision to go ahead with the second stage was taken 1 year after the original surgery. A period of 2 years after the second stage, the patient is infection-free, with a painless, well-functioning knee arthroplasty, and no systemic disorder was diagnosed (Fig. 6).