Medial Gastrocnemius Flap in the Course of Treatment for an Infection at the Site of a Total Knee Arthroplasty.

Abstract

The pedicled medial gastrocnemius flap provides a robust coverage option for most soft-tissue deficiencies over the distal anterior aspect of the knee encountered in the setting of an infection after total knee arthroplasty. Position the patient supine with an ipsilateral sterile thigh tourniquet to allow room for harvest of a split-thickness skin graft as needed. Perform the arthroplasty to address the underlying deep infection (e.g., irrigation and debridement with exchange of modular components, component removal with antibiotic spacer placement, antibiotic spacer exchange, or second-stage reimplantation) prior to the medial gastrocnemius flap that is utilized for soft-tissue coverage. Use one of two different surgical approaches for the exposure and elevation of the medial gastrocnemius muscle and the identification of its vascular pedicle: the medial approach or the posterior midline approach. Protect the sural artery pedicle in the popliteal fossa because it is key to raising a viable medial gastrocnemius flap. Rotate the flap and transpose it anteriorly over the defect either through a subcutaneous tunnel or by dividing the intervening skin bridge. Complete the layered skin closure and place a split-thickness skin graft over the remaining exposed muscle flap and a nonadherent compressive bolster dressing or negative-pressure device over the skin graft to prevent hematoma under the skin graft. Progress range of motion of the knee once the flap and graft show evidence of survival, while an appropriate antibiotic regimen is completed. We recently reported the largest English-language series, to our knowledge, of medial gastrocnemius flaps performed for soft-tissue coverage in the course of treatment for infection after total knee arthroplasty13.