Ethel Armstrong worked with John Charnley (hip replacement operation pioneer) and then as an advisor to the Liverpool Breast Screening Service.
Armstrong worked with John Charnley during his early work on hip operations, before he received his knighthood. He pioneered the hip replacement operation, which is now one of the most common operations both in the UK and elsewhere in the world, and created the "Wrightington centre for hip surgery". Armstrong worked as a tutor and advisor to the Liverpool Breast Screening Service until 1989, when she retired. 
