Background: Proximal humeral replacement with endoprosthesis is a well-accepted procedure for treatment of malignant or aggressive bone tumors. In Thailand, the Thai modular proximal humeral (TMPH) endoprosthesis has been manufactured and little is known about the results following its implantation.

Objective: To report the short-term functional and oncologic outcomes following implantation of the TMPH endoprosthesis system and its complications.

Material and Method: We prospectively reviewed 10 consecutive patients treated with wide proximal humeral resection and implantation with the TMPH endoprosthesis in our three centers: six patients from Lerdsin General Hospital, three patients from Maharaj Nakorn Chiang Mai Hospital, and one patient from King Chulalongkorn Memorial Hospital. The mean age was 52 years old, range (17 to 78). The mean resection length was 13 cm, range (9 to 17). The mean follow-up time was 9.7 months, range (0.6 to 19.5); the mean follow-up time for surviving patients was 14.5 months, range (8.7 to 19.5). The musculoskeletal tumor society (MSTS) score, radiographs, and complications were recorded.

Results: Three patients died of disease at 2.6 months, range (2.1 to 4.1) and one patient died of his underlying disease at 0.6 months after the surgery. There were no infection, proximal migration, recurrence, or implant-related complication. The mean MSTS score was 21, range (18 to 25). The mean active shoulder abduction was 42°, range (20° to 80°) and flexion was 45°, range (25° to 85°). The mean passive shoulder abduction was 104°, range (45° to 170°) and flexion was 102°, range (45° to 170.5°).

Conclusion: Although longer follow-up is required, our satisfactory result showed that reconstruction using the TMPH endoprosthesis is a practicable option with good functional result and low complication rate.

Keywords: Proximal humerus, Endoprosthesis, Outcome, Complications