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Case

Knee gastrocnemius flap

A 48-year-old epileptic patient had sustained burn wounds after falling into the fire in rural Tanzania. He did not come to the hospital immediately but went to a traditional healer first. This case demonstrates the treatment of the deep burn wound on the upper leg and knee with the patella exposed.

A muscle flap was used to cover the defect on the knee.

Medical history

The patient had started convulsing and fell into an open fire, burning his left hand and his left thigh and knee. He had been treated with local herbs without success and arrived in the hospital 3 days after the burn injury took place. As a known epileptic patient, he was on phenobarbital treatment. He was married, but had no children.

Physical examination

The patient did not appear ill, had no fever and no difficulties breathing. In this example we will focus on the deep burns on the left thigh and knee. Hemoglobin level 9.0g/dL. Dry eschar was visible and no signs of infection were observed (Photo 1).

Conservative management

To prevent infection, closed dressings with antibiotic ointment were applied.

Intramuscular tramadol, oral diclofenac and paracetamol were provided for pain relief. Phenobarbital was continued. The patient and his relatives took time to find money for the surgery (Photo 2). The eschar became more and more dry over time (Photo 3).

Surgery

Because the patient was stable, with no signs of infection, there was no reason to hurry with the surgery and the relatives took their time to find money to pay for the procedure.

It was anticipated that the burn on the knee was deep, probably extending into the patella.

As explained in the example of the knee burn wound from the Netherlands, several options are available to reconstruct the soft tissue on the patella. In this case an escharectomy was performed on the 16th day after the burn injury (Photo 4 and 5). During this procedure the thigh was grafted and it was opted to wait for granulation to form on the exposed bone and tendon of the patella. Therefore, silver sulfadiazine (SSD) was applied (Photo 6).

Since a local fasciocutaneous flap was not a valid option in this case with extended burn wounds in the area, a medial gastrocnemius muscle flap (regional flap) was chosen to cover the patella. With a dorsomedial skin incision, the muscle belly was harvested and rotated anterosuperiorly on its pedicle, the medial sural artery. The muscle was grafted with a SSG (Photos 10 and 11).

Postoperative care

After the escharectomy, the grafted area was kept dressed with Vaseline gauzes for 3 days. The patella area was dressed daily with a new SSD layer.

After 3 days the skin graft showed good take (Photo 9).

After five days, the wound bed in the patella area showed necrotic tissue again (Photo 10). The team decided that a new debridement with a flap would be a better option than and waiting for granulation tissue again.

Outcome

The graft showed a good take, but the postoperative healing process was complicated by exudate and crust formation for a couple of weeks, probably due to some remaining non-vital tissue underneath the flap and a low-grade infection. Oral antibiotics were prescribed for 2 weeks combined with topical tetracycline ointment and the situation improved over time.

Full knee function was regained after 3 months with only a small remaining wound at that time (Photos 12, 13 and 14).

Lessons learned

Managing Exposed Bone and Tendon: Exposed bone and tendon cannot be grafted immediately due to inherent complexities.

Considerations in Serial Debridements: Serial debridements and awaiting granulation tissue formation are viable options, but they come with limitations. Exposed tendon and bones may risk necrosis during the waiting period.

Careful Decision-Making in Flap Usage: The decision to utilize flaps for covering defects in acute burns requires careful consideration. Flaps can only be used once, necessitating a clean wound bed with viable tissue. However, achieving this can be challenging when limited debridement is possible without risking damage to vital structures. Balancing the timing and technique of surgery is crucial, ensuring that surgical intervention is warranted and expected to yield superior outcomes compared to conservative treatment.

Case

Knee gastrocnemius flap