The treatment of osteoarthritis in patients with phocomelia with total knee arthroplasty is challenging due to the unusual anatomy and severe deformities. The authors present a case of phocomelia caused by thalidomide with end-stage osteoarthritis and grossly medialized patella. The patient was treated with a cemented constrained non-hinged prosthesis and patelloplasty. Six months later, the patient had complete relief of pain and was able to walk without walking assistance. To our knowledge, total knee replacement in a patient with phocomelia caused by thalidomide has not been described in literature.