Mayor Thomas Menino was recovering and resting comfortably after surgery on Saturday to repair a fracture on the smaller of the two bones in his lower right leg.
Menino, 70, twisted his ankle and fractured his distal fibula while on his way to an event on Friday.
Surgeons at Brigham and Women's Hospital repaired the bone on Saturday morning. They said the surgery lasted less than an hour and included the placement of a plate and screws to fix the broken bone.
"This common injury often requires surgical repair," chief of orthopedic trauma service Dr. Mitchel Harris and orthopedic surgery instructor Dr. Michael Weaver said in a statement.
Menino tolerated the surgery well and without complication, the doctors said. He will be in a walking boot and will need crutches for the next couple of months, they said.
"It is our expectation that Mayor Menino will make a full and complete recovery," the statement said.
Menino, a Democrat, last month told well-wishers gathered at historic Faneuil Hall that he wouldn't seek re-election to an unprecedented sixth term in office.
The fracture is the latest in a series of health issues that have dogged Boston's longest-serving mayor since the end of last year.
He spent about six weeks at Brigham and Women's Hospital, leaving just in time for Christmas, after being admitted for treatment of a respiratory infection that developed during a vacation in Italy. While at the hospital he suffered complications including a compression fracture in a vertebra in his spine. He also was diagnosed with Type 2 diabetes.
Menino's long stewardship of the city came at a critical time, when traditional urban ethnic enclaves began to give way to waves of new immigrants and younger professionals.
He worked to make Boston more fun and livable. Despite the city's famously narrow, twisting streets, Menino ushered in a bicycle-sharing program and named a bicycle czar to negotiate conflicts between bicyclists and drivers.
He also struggled to try to improve the city's school system and wasn't shy about wearing his sympathies on his sleeve.