Patients undergoing resection of proximal humeral tumors require reliable reconstruction methods that preserve limb function while minimizing complications. In this retrospective comparative study of 58 patients, the authors evaluated outcomes following reconstruction with either a modular endoprosthesis (humeral hemiarthroplasty) or a cement spacer after wide tumor resection. Clinical, radiological, and operative data were reviewed, and functional recovery was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system.

Nineteen patients underwent modular endoprosthesis reconstruction, while 39 patients received cement spacer reconstruction. The modular endoprosthesis group demonstrated a slightly higher mean MSTS score (24.8 ± 1.1) compared with the cement spacer group (23.9 ± 1.4), reaching statistical significance (P = 0.018). However, complication rates were comparable between the two groups (26.3% vs. 28.2%, P = 0.879), and neither axillary nerve nor deltoid muscle resection significantly influenced postoperative functional outcomes.

The findings suggest that both modular endoprostheses and cement spacers provide durable and effective reconstructive options following proximal humeral tumor resection. Although endoprostheses achieved marginally higher functional scores, the difference was small and did not translate into a clear clinical advantage over the substantially less expensive cement spacer. These results support cement spacer reconstruction as a cost-effective alternative for limb salvage, offering comparable durability, complication rates, and overall functional outcomes.