Dr. William G. Hamilton, who because the attending orthopedic surgeon for New York Metropolis Ballet spent greater than 40 years fixing bone spurs, tendinitis, bursitis, torn ligaments and what he known as “the Nutcracker Fracture,” died on March 29 at his residence in Croton-on-Hudson, N.Y. He was 90.

His spouse, Linda Hamilton, mentioned the trigger was congestive coronary heart failure.

Ballet dancers could be the “athletes of God,” as Albert Einstein supposedly mentioned. However till Dr. Hamilton got here alongside, they have been handled extra like ethereal beings than bodily our bodies that would crack, tear and in any other case crumble beneath the acute and infrequently unnatural pressures of repeated pliés and grand jetés.

In truth, it was George Balanchine, the choreographer who famously insisted that his dancers stoically work by means of their stubbed toes and sprained ankles, who requested Dr. Hamilton to change into the primary in-house physician for the 80-plus members of New York Metropolis Ballet, in 1972.

Dr. Hamilton instantly mentioned sure, although he knew nothing about ballet. He immersed himself within the artwork, attending weekend courses and turning into near Balanchine and, later, the dancer and choreographer Mikhail Baryshnikov, who in 1980 employed him to be the attending surgeon for American Ballet Theater as nicely.

A courtly 6-foot-3 Southerner, Dr. Hamilton turned a favourite and even revered determine round Lincoln Middle. He had a disarming bedside method that put younger dancers relaxed once they got here to him anxious {that a} sprained ankle would possibly finish their profession.

He stored a ballet barre in his inspecting room, and he was famend for catching early indicators of power, doubtlessly debilitating issues simply by asking a dancer to undergo a couple of routine motions.

Early on, he realized that whereas dancers suffered the identical sorts of accidents athletes did, they received them in obscure methods and locations. He noticed, for instance, that the speedy actions required by Balanchine’s ballets got here with the chance of foot and ankle harm, whereas the leaps and bounds extra widespread beneath Mr. Baryshnikov have been extra threatening to the hips and knees.

“From the very starting, I realized that though they get the identical accidents as athletes, dancers are artists first,” he informed Dance Journal in 2011.

When Dr. Hamilton began out, within the early Seventies, there was no such factor as dance medication, and certainly foot and ankle accidents have been a largely understudied subject of orthopedic medication.

He constructed up each fields by means of lectures and journal articles during which he recognized beforehand understudied accidents; he was among the many first to explain the Nutcracker Fracture, for instance, which includes a number of breaks within the cuboid bone within the foot. He was president of the American Orthopaedic Foot and Ankle Society from 1992 to 1993, and in the present day each sizable dance firm within the nation has an orthopedic surgeon on name.

“Invoice was the king of orthopedic dance medication,” Glenn Pfeffer, the co-director of the Cedars-Sinai/USC Glorya Kaufman Dance Medication Middle in Los Angeles, mentioned in a cellphone interview.

Dr. Hamilton continued to carry out surgical procedure till he was 81 and consulted till a couple of years in the past, lengthy after most physicians would have hung up their scalpels.

“I’d have retired a very long time in the past if it wasn’t for the dancers,” he mentioned in a 2016 interview with the journal Princeton Alumni Weekly. “It’s very rewarding as a result of they love what they do. They simply wish to dance; they wouldn’t wish to do the rest.”

William Garnett Hamilton didn’t got down to be a Manhattan physician, not to mention a balletomane. He was born on Jan. 11, 1932, in Altus, Okla., the place his father, Milton Hamilton, was a salesman and his mom, Elizabeth (Garnett) Hamilton, was a homemaker.

The household moved to Shreveport, La., when he was very younger. After his mother and father divorced, his mom remarried and moved to Portage, Wis., the place her new husband owned a plastics manufacturing firm.

William graduated from Princeton in 1954 with a level in engineering, and after two years within the Military he joined his stepfather’s enterprise in Wisconsin. He married and had a toddler; by his mid-20s, he mentioned, he might see his total life unfolding earlier than him. He didn’t like what he noticed.

Towards his mother and father’ needs that he keep to run the household firm, he utilized to medical faculty. He was accepted at Columbia, one of many few faculties that took older college students (he was 28 when he enrolled). He determined to give attention to orthopedics — a subject that he mentioned was not not like engineering, with muscle mass and joints standing in for ropes and levers. He graduated in 1964 and, after a number of years of residency, opened a follow in Midtown Manhattan in 1969.

Along with his work with the 2 ballet corporations, he offered the identical companies to the businesses’ affiliated faculties, the Faculty of American Ballet and the Jacqueline Kennedy Onassis Faculty, and he consulted for quite a few Broadway exhibits and New York sports activities groups, together with the Knicks and the Yankees.

His first two marriages led to divorce. He met his future third spouse, Linda Homek, when she was a dancer with New York Metropolis Ballet. She later obtained a doctorate in psychology from Adelphi College, on Lengthy Island. In 2000, she and Dr. Hamilton created a multidisciplinary wellness group, together with a dietitian and a therapeutic massage therapist, to look after the corporate’s dancers, a mannequin that has since been adopted by different ballet corporations.

Alongside together with his spouse, Dr. Hamilton is survived by his sister, Ann Kirk; his sons, William Jr. and Lewis; and three grandchildren.