Treatment of Humeral Shaft Aseptic Nonunions in Elderly Patients With Opposite Structural Allograft, BMP-7, and Mesenchymal Stem Cells

Humeral shaft aseptic nonunions occur in 2% to 10% of patients managed conservatively and 10% to 15% of patients treated surgically. The complex muscular and neurovascular anatomy of the upper limb makes the surgical approach to the fracture site demanding and risky, especially when previous surgeries have been attempted. The clinical consequence of atrophic humeral shaft nonunions is a severe functional limitation that may significantly affect activities of daily living, especially in the elderly. The surgical treatment of humeral shaft nonunions is challenging for orthopedic surgeons. Patients with atrophic nonunions require both a stable fixation and enhancement of the biologic response because of the weak biologic reaction observed at the fracture site. The gold standard of treatment in elderly patients has not been described. Nonetheless, older age and comorbidities are associated with potentially malignant nonunions. This study reports the authors' experience using opposite cortical allograft combined with bone morphogenetic protein 7 and mesenchymal stem cells to treat humeral shaft atrophic nonunions in 2 elderly patients. The nonunion site healed at 4 months (patient 1) and 8 months (patient 2) postoperatively, with full return to activities of daily living and no pain. Neither patient reported complications of the radial nerve, which is at high risk of injury during this type of surgery. The only reported complication (patient 2) was an intraoperative longitudinal partial distal humeral fracture, probably caused by compression screw overtightening. The use of a locking plate and opposite cortical allograft, combined with BMP-7 and mesenchymal stem cells, represents a safe and effective treatment for malignant nonunions in older patients.