Major orthopaedic surgery on the leg and thromboembolism.

@article{ParkerWilliams1991MajorOS,
  title={Major orthopaedic surgery on the leg and thromboembolism.},
  author={John Parker-Williams and Russell Vickers},
  journal={BMJ},
  year={1991},
  volume={303 6802},
  pages={531-2}
}