In the early 1890s, Kelly pursued the field of urogynecology and is known for establishing gynecology as its own field of study and through his textbook, Operative Gynecology, established a systematic approach to gynecological medicine and surgery.

Along with "Kelly's stitch",  he developed other new surgical techniques and devices.

He identified what became known as "Kelly's sign", a way to find the ureter during surgeries.
 Because ureters tend to adhere to the peritoneum instead of maintaining its normal position along the psoas muscle during operations, it can be hard to find.
 Kelly's sign is a technique of applying gentle pressure to the ureters to cause peristalsis, or worm-like muscle contraction to identify the ureter.

Kelly developed better methods for examining the bladder, improving on methods he learned from Pawlik.

He invented the "Kelly speculum" for rectal examinations, as well as "Kelly's small cylindrical specular", a set of devices for vaginal examinations, some of which were specially designed for virgins.

He also invented "Kelly's forceps" or "Kelly's Clamp",  curved hemostatic forceps that resemble a pair of scissors.
Instead of sharp teeth or the blade of scissors, these forceps have blunt grips.
They are used to clamp vessels to control blood flow and are arguably among the most common and best known surgical instruments.
There are also subcategories like the tenaculum forceps and the alligator forceps.

To promote safety during surgery, Kelly used nitrous oxide for anesthesia, absorbable sutures during operations, and electrical lights for better lighting during surgery.
He was also one of the first surgeons to use an operating suit, clothing made up of sterilized linens.
Additionally, in order to minimize the possibility of wound infection, he invented a wound sealing procedure.
First, he soaked two layers of sterilized gauze with celluloid and bichloride to secure the dressing to the skin.
Then, he dusted the surface with iodoform and boric acid powder.
Finally, until the stitches were removed, the wound was not exposed.

During the late 1890s, Kelly became interested in gynecological cancers.
To reduce bleeding for cervical and endometrial cancers, he ligated the internal iliac artery, a technique that would come to be used in postpartum hemorrhages.
Kelly also dabbled with the use of radium in 1904.
He used the radium to treat uterine hemorrhages and fibroid tumors and published these techniques in the Journal of the American Medical Association in 1914.
Additionally, in 1917, his own clinic had about 5.5 grams of radium and was one of the country’s leading centers for radiation therapy for cancer treatment at the time.
In the early 1890s, Kelly pursued the field of urogynecology and is known for establishing gynecology as its own field of study and through his textbook, Operative Gynecology, established a systematic approach to gynecological medicine and surgery.
Along with "Kelly's stitch",  he developed other new surgical techniques and devices.
He identified what became known as "Kelly's sign", a way to find the ureter during surgeries.  Because ureters tend to adhere to the peritoneum instead of maintaining its normal position along the psoas muscle during operations, it can be hard to find.  Kelly's sign is a technique of applying gentle pressure to the ureters to cause peristalsis, or worm-like muscle contraction to identify the ureter.
Kelly developed better methods for examining the bladder, improving on methods he learned from Pawlik.
He invented the "Kelly speculum" for rectal examinations, as well as "Kelly's small cylindrical specular", a set of devices for vaginal examinations, some of which were specially designed for virgins.
He also invented "Kelly's forceps" or "Kelly's Clamp",  curved hemostatic forceps that resemble a pair of scissors. Instead of sharp teeth or the blade of scissors, these forceps have blunt grips. They are used to clamp vessels to control blood flow and are arguably among the most common and best known surgical instruments. There are also subcategories like the tenaculum forceps and the alligator forceps.
To promote safety during surgery, Kelly used nitrous oxide for anesthesia, absorbable sutures during operations, and electrical lights for better lighting during surgery. He was also one of the first surgeons to use an operating suit, clothing made up of sterilized linens. Additionally, in order to minimize the possibility of wound infection, he invented a wound sealing procedure. First, he soaked two layers of sterilized gauze with celluloid and bichloride to secure the dressing to the skin. Then, he dusted the surface with iodoform and boric acid powder. Finally, until the stitches were removed, the wound was not exposed.
During the late 1890s, Kelly became interested in gynecological cancers. To reduce bleeding for cervical and endometrial cancers, he ligated the internal iliac artery, a technique that would come to be used in postpartum hemorrhages. Kelly also dabbled with the use of radium in 1904. He used the radium to treat uterine hemorrhages and fibroid tumors and published these techniques in the Journal of the American Medical Association in 1914. Additionally, in 1917, his own clinic had about 5.5 grams of radium and was one of the country’s leading centers for radiation therapy for cancer treatment at the time.
Howard Atwood Kelly