A 44-year-old patient was treated with elbow arthrodesis at a position of 90° due to primary osteoarthritis. Seven years later he was introduced to us due to progressive pain of both elbows. Although the arthrodesis had consolidated uneventfully, the patient felt massive restrictions due to eliminated extension/flexion and persistent pain. The right elbow developed primary osteoarthritis likewise. We performed arthroscopic debridement and arthrolysis of the right elbow. After a recovery phase of 2 months we converted the arthrodesis of the left elbow to total elbow arthroplasty. Three months later he achieved active flexion/extension of 0-30-100°, had no pain and was able to perform most activities of daily living again with his left elbow. Movement against resistance was possible, whereas strength was limited compared to the right side. After 9 months the flexion-extension arc was 0-25-110°. This case shows that conversion of arthrodesis to arthroplasty is possible at the elbow. Despite the long arthrodesis period of 7 years the patient was able to activate the elbow extensors and flexors.