Introduction. Limb salvage surgery following proximal ulna resection poses a challenge in reconstruction of the complex elbow anatomy. Various reconstruction methods described offer inadequate restoration of function and stability. Following resection of proximal ulna tumors, we aimed to restore the joint using the resected osteochondral segment of proximal ulna treated with extracorporeal irradiation and reimplantation. Questions/Purposes. (1) Does irradiated osteoarticular autograft reconstruction for proximal ulna allow anatomical joint restoration and what are the oncological and functional outcomes? (2) Is there evidence of graft-related complications or osteoarthritis at a minimum of 2 years follow-up with irradiated osteoarticular autografts for the proximal ulna? (3) How does our method of reconstruction fare as compared to reported reconstruction options in the literature? Materials and Methods. 3 patients with primary bone tumors involving the proximal ulna underwent limb salvage surgery with en bloc resection and reconstruction using the resected bone after treating it with extracorporeal irradiation of 50 Gy. Minimum follow-up of 2 years was considered for assessment of final outcomes. Radiographs were assessed for bony recurrence, union across osteotomy junction, and signs of joint arthritis. Functional outcome measures included range of movement, muscle power testing, and functional and disability scores. Results. 2 complete and 1 partial olecranon involving proximal ulnar resections were performed for three cases of Ewing's sarcoma in 2 males and 1 female. Follow-up ranged from 28 to 42 months, and all patients continue to remain disease free. All 3 patients have achieved full range of flexion-extension and pronosupination movement in comparison to the contralateral side. Muscle power for flexion and extension was 5/5. MSTS score: 100% (30/30); MEPS score: 100; and DASH score: zero were achieved for all patients. Union across osteotomy junctions at median follow-up of 8 months without need for intervention/bone grafting was achieved. No complications related to joint laxity/subluxation, infection, graft fracture, or implant failure was noted. None of the patients have clinical or radiological signs of joint arthritis across the irradiated articulation. Conclusion. Biological restoration of elbow anatomy using osteoarticular irradiated graft for proximal ulna reconstruction offers great joint stability and functional outcomes. Although the potential risks of infection and graft failure need to be considered, reconstruction with the size-matched radiated autograft eliminates donor site morbidity, offers a low-cost alternative to endoprosthesis, and provides outcomes superior to any other methods of reconstruction as analyzed from the literature. [ABSTRACT FROM AUTHOR]