The surgical treatment of stage 2 posterior tibial tendon deficiency (acquired adult flexible flatfoot) uses both soft tissue and bony procedures to realign and reconstruct the foot. The most common realignment procedures involving the calcaneus are a medial displacement calcaneal osteotomy, a lateral column lengthening, or a combination of both. A modification of existing lateral column lengthening techniques was adapted to be used in combination with the medial displacement calcaneal osteotomy. This technique involves a "Z" osteotomy of the calcaneal neck. This osteotomy enables distraction of the lateral column and medial rotation of both the hindfoot and forefoot. An intercalary bone graft is not required. The "Z" osteotomy provides additional correction of forefoot and hindfoot position, when needed, but minimizes the problems that have been reported with other techniques of lateral column lengthening.