Operative technique
The patient was supine under general anesthesia, padding the left gluteal area. The incisions started in the midline of the medial and lateral aspects of the thigh. The medial incision was carried down, starting ten centimeters below the inguinal fold until the distal third of the leg. The lateral incision began from the lateral aspect of the greater trochanter to the same level as the medial incision distally. The anterior flap was cut 10 centimeters proximal to the joint line in the knee and the posterior flap at the distal third of the leg, ensuring the complete excision of the previous scar tissue and sinus tracts (Figure 2 ).
We proceeded with distal femur endoprosthesis extraction and aggressive debridement of the infected tissues (Figure 3A ).
The superficial femoral artery and vein were accessed from the medial incision, and careful dissection was performed through the adductor hiatus until the popliteal fossa. At the lower border of the poplìteus muscle, we ligated the anterior tibial artery, and the tibioperoneal trunk was preserved.
The posterior tibial artery was dissected distally and ligated at the level of the distal third of the leg, preserving the posterior tibial neurovascular bundle as distally as possible that is required to provide perfusion and sensation to the flap. Traction neurectomies were performed on the superficial and deep peroneal nerves. The tibial osteotomy and foot amputation were performed at the distal diaphyseal metaphyseal junction approximately 6 cm proximal to the ankle joint. The fasciocutaneous distal cut was made 3 cm distal to the tibial cut. The fibula was disarticulated proximally and excised from the interosseous membrane. It was used later as an autogenous strut graft to augment the medullary canal, bridging the remaining femur and the tibia autograft (Figure 3B ).
The lateral and anterior muscular compartments of the leg were transected completely, and the superficial and posterior muscular regions were preserved with their tibial osseous attachments. Then, the distal tibia and the posterior myofasciocutaneous flap were rotated 180 degrees proximally, joining the distal end of the tibia with the distal end of the femur (Figure 3C ).
The front surface of the tibia was then lying with the posterior compartment and thigh muscles. The osteosynthesis was made with a 4,5 dynamic compression plate alongside the new femorotibial construct, achieving compression between the fragments and with a fibular autograft strut spanning the osteotomy site inside the medullary canals (Figure 3D ). The stump coverage was complete without skin tension of the flaps.
The resultant total construct length using the technique was 35 cm, contrasting to 13 cm in the case of unaugmented amputation (Figure 4 ).