This app was mentioned in 4 comments, with an average of 4.50 upvotes
I haven't used it, but I know this is what you are looking for. I must say that the app needs a lot of storage. It's totally free, without adds and works offline.
Wikipedia is not always the best or most detailed source of information, but it is a very good first step and completely downloadable to a local PC or even to a local network.
https://en.wikipedia.org/wiki/Dislocated_shoulder
Free alternative Offline Medical Wikipedia https://play.google.com/store/apps/details?id=org.kiwix.kiwixcustomwikimed
Having the offline wikimed is very useful when you don't have data or wifi
https://play.google.com/store/apps/details?id=org.kiwix.kiwixcustomwikimed