Introduction and importanceReconstruction of large skeletal defects pose significant challenges for orthopedic surgeons, particularly in cases of chronic skeletal defects where the surrounding structures differ substantially from the original anatomical structures, further complicating management.Case presentationA 54 year old male patient presented with a large skeletal defect after osteomyelitis surgery. The treatment of choice for this case was reconstruction using a total humerus megaprosthesis. The prosthesis was custom-designed with a reversed shoulder joint and a total elbow joint, which were 3D printed using CT-Scan imaging.Clinical discussionA short-term follow-up revealed improvements for the patient in arm functionality and expectation-based satisfaction at 6 months post-surgery.ConclusionTotal humerus megaprosthesis joint replacement may be a promising option for treating chronic humeral defects.