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.
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.
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 2).
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 3). The eschar became more and more dry over time (Photo 4).
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 5 and 6). 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 7).
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 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).
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 8).
After five days, the wound bed in the patella area showed necrotic tissue again (Photo 9). The team decided that a new debridement with a flap would be a better option than and waiting for granulation tissue again.
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).
- Exposed bone and tendon cannot be grafted straight away.
- Serial debridements and waiting for granulation tissue is an option but has its limitations. Exposed tendon and bones may become necrotic in the meantime.
- The decision to use a flap to cover defects in acute burns needs to be taken carefully because the flap can only be used once. The wound bed should be clean and the tissue alive. This can be difficult if only limited debridement can be done without damaging vital structures. The challenge is to operate at the right moment using the right technique, and only when surgery is expected to be superior to conservative treatment.