In any writing the opening sentence has a heavy responsibility. It must seize the reader's attention and make him want to continue, indicate the general subject matter, and impart its information in a pleasing and attractive form. Students in journalism courses are taught a formula for writing the opening sentence—the who-where-when-what-how approach. This will tell who did what, where and when he did it, and will give whatever attendant circumstances can fit into a single sentence. But medical writing is different from a newspaper report.
The first sentence has a dual function: it must carry some essential information, particularly the problem under consideration, and at the same time gently translate the reader into the body of the article. There is no need to crowd all the specific information that the news reporter tries to express, nor yet to provide a setting or background such as a short story writer might
King LS. The Opening Sentence. JAMA. 1967;202(6):535-536. doi:10.1001/jama.1967.03130190141022