Nearly a year after the terrorist attacks at the Boston Marathon, all of the people who lost legs are ambulatory, and some have returned to work, according to a physician at the rehabilitation hospital where all but one were treated.

David Crandell, medical director of the amputee program at Spaulding Rehabilitation Hospital in Boston, said the 15 amputees who recovered there after stays at acute care hospitals have progressed at different rates, physically and psychologically, over the past 11 months.

"All of the amputees are at least working with prostheses, some better than others," Crandell said. "A number of amputees are back working [at their former jobs], some full time and some part-time," he said.

Sixteen people lost limbs when two home-made bombs packed with nails, pellet, springs and other metal shards were set off 12 seconds apart near the finish line of last year's marathon. Two people lost both legs. Many of these most seriously injured have endured numerous surgeries and struggled with infections, skin grafts and other complications. Some have suffered a condition called "heterotopic ossification," in which boney deposits develop in soft muscle tissue, a problem most often experienced by people wounded in combat. Some suffered such severe damage to their remaining legs that walking remains difficult.

The youngest amputee, Jane Richard, who was 7 years old at the time of the attack, is doing well, Crandell said. She has returned to school but has not yet been able to resume Irish step-dancing, he said. Irish step-dancers across the country have been raising money for her. The girl's brother, 8-year-old Martin Richard, was killed in the attack, and their mother was severely wounded.

Others have had smoother roads to recovery. In general, people whose legs were amputated above the knee have a more difficult recovery than those who retain the knee joint.

Many people believe "everything is fine, they’ll just get a prosthesis. It’s not that simple," Crandell said.

Spaulding plans to track the survivors' progress for 10 years, Crandell said. In all, 33 victims from the bombing spent time at the rehabilitation hospital. He offered an informal assessment as the one-year anniversary of the attack approaches.

Authorities have said that two brothers, Tamerlan and Dzhokar Tsarnaev, are responsible for the attack. Tamerlan Tsarnaev was killed in a shootout with police. His younger brother faces a 30-count indictment that accuses him of killing three people and injuring more than 260.

Probably because the bombs were placed on the ground, no one lost an arm in the attack. One woman seen at Spaulding lost a finger and is about to undergo her ninth surgery on the hand, Crandell said.

Psychologically, doctors and therapists are seeing a wide variety of reactions as the anniversary of the attack approaches, Crandell said. The city of Boston is planning a day of ceremonies April 15 honoring the victims and others affected by the bombing. The 2014 Boston Marathon will be held April 21.

"It’s mixed," Crandell said "Some people are, in some ways, looking forward to reconnecting, here at the hospital [and elsewhere]. And others don’t feel that’s something they can do."

Money continues to be an issue for the most severely wounded. J.P. Norden, one of two brothers who lost their right legs in the bombing, has told The Washington Post that the $1.2 million he received from the One Fund charity for survivors will not be enough to meet his long-term needs.

The fund distributed $60.9 million  based on each patient’s length of stay in an acute care hospital. The charity has continued to take in millions of dollars more and will allocate it July 1. Crandell and other physicians are part of a panel that is advising the fund on the best ways to meet patient needs.

Like others before him, Crandell said the work of first responders, the decision to send the wounded to multiple area hospitals and the acute care they received there had a dramatic impact on survivors’ long-term recoveries.

“I do credit, obviously, the first responders and the people at the acute trauma hospitals. When patients arrived here, they were good rehabilitation patients. They were ready.”