The gastrocnemius muscle is versatile in flap repair of defects from anterior knee to lower leg. We describe a case of extensor reconstruction using an extended medial gastrocnemius myocutaneous flap. A medial gastrocnemius flap was raised distal to its musculotendinous insertion. At its point of rotation, it was anchored to the anterior periosteum of the tibia, hence obliterating dead space and recreating the extensor mechanism of the knee. The patient had no flap loss and was able to ambulate independently. He showed no extensor lag. Our flap is unique in that it is the only medial gastrocnemius flap that has shown no extensor lag as well as complete flexion of the knee following a disrupted entire quadriceps mechanism. It is also the first myocutaneous gastrocnemius flap that has been described for this purpose.