Rader, Christof P, Thomas Barthel, Matthias Haase, Matthias Scheidler, and Jochen Eulert. 1997. “Heterotopic Ossification After Total Knee Arthroplasty: 54 615 Cases After 1-6 years’ Follow-up”. Acta Orthopaedica 68 (1):46-50. https://doi.org/10.3109/17453679709003974.