Abrahamsson, S.-O., Ahlgren, S.-A., Dahlström, J. A., Ohlin, P., & Stigsson, L. (1984). Extopic bone after hip replacement: Excision and free fat transplants in four cases. Acta Orthopaedica, 55(6), 589–592. https://doi.org/10.3109/17453678408992401