The origin of chain saws in surgery is debated. A "flexible saw", consisting of a fine serrated link chain held between two wooden handles, was pioneered in the late 18th century (circa 1783–1785) by two Scottish doctors, John Aitken and James Jeffray, for symphysiotomy and excision of diseased bone, respectively.[2] It was illustrated in the second edition of Aitken's Principles of Midwifery, or Puerperal Medicine (1785) in the context of a pelviotomy [3] Jeffray claimed to have conceived the idea of the chain saw independently about that time, but it he was not able to have it produced until 1790. In 1806, Jeffray published "Cases of the Excision of Carious Joints by H. Park and P. F. Moreau, with Observations by James Jeffray, M.D." In this communication, he translated Moreau's paper of 1803. Park and Moreau described successful excision of diseased joints, particularly the knee and elbow. Jeffray explained that the chain saw would allow a smaller wound and protect the adjacent neurovascular bundle. Symphysiotomy had too many complications for most obstetricians, but Jeffray's ideas became accepted, especially after the development of anaesthetics. Mechanised versions of the chain saw were developed but in the later 19th century, it was superseded in surgery by the Gigli twisted-wire saw. For much of the 19th century, however, the chain saw was a useful surgical instrument.

Historical osteotome, a medical bone chainsaw
A precursor of the chain saw familiar today in the timber industry was another medical instrument developed around 1830 by German orthopaedist Bernhard Heine. This instrument, the osteotome, had links of a chain carrying small cutting teeth with the edges set at an angle; the chain was moved around a guiding blade by turning the handle of a sprocket wheel. As the name implies, this was used to cut bone