Nygaard, Kevin H, et al. “Intraoperative Single-Dose Methadone Significantly Affects Postoperative Morphine Consumption in Older Patients With a Hip Fracture: The MetaHip Randomized Controlled Trial”. Acta Orthopaedica, vol. 97, Apr. 2026, pp. 255–264, doi:10.2340/17453674.2025.44754.