A boy who underwent a double hand transplant was able to fulfil his dream of swinging a baseball bat just a year after surgery.
Zion Harvey was also able to write and also feed and dress himself independently 18 months after the procedure which took nearly 11 hours.
The American youngster, who was aged eight when the procedure took place, is able to complete the tasks following months of occupational therapy and psychological support, according to a medical report published in The Lancet Child and Adolescent Health journal.
The report also documents a series of setbacks, including treatment of numerous rejections of the hands and extensive rehabilitation.
Dr Sandra Amaral, of the Children's Hospital of Philadelphia, said: "Our study shows that hand transplant surgery is possible when carefully managed and supported by a team of surgeons, transplant specialists, occupational therapists, rehabilitation teams, social workers and psychologists.
"Eighteen months after the surgery, the child is more independent and able to complete day-to-day activities.
"He continues to improve as he undergoes daily therapy to increase his hand function and psychosocial support to help deal with the ongoing demands of his surgery."
In July last year, Chris King became the first person in the UK to have a double hand transplant in a pioneering operation at Leeds General Infirmary.
The new study documents the progress of the first double hand transplant surgery in a child.
Zion was already receiving immunosuppression medication for a kidney transplant which was needed after he contracted the life-threatening infection sepsis when he was two.
The infection also meant the youngster had to have his hands and feet amputated.
Before he underwent the double hand transplant, Zion had limited ability to dress, feed and wash himself using his residual limbs or specialist equipment.
When asked what he hoped to do following surgery, he told doctors he wanted to be able to climb monkey bars and grip a baseball bat.
His mother hoped her son would be able to dress, brush his teeth and cut food independently.
The surgery took place in July 2015 at the Children's Hospital of Philadelphia in collaboration with Penn Medicine when a suitable donor became available.
The procedure, which lasted 10 hours and 40 minutes, involved four medical teams working on the donor and recipient limbs.
Within days of the surgery, Zion was able to move his fingers using the ligaments from his residual limbs.
Six days after the transplant he began daily occupational therapy, including video games and exercises using finger lights and puppets, as well as daily tasks such as writing and using a knife and fork.
By six months he could move the transplanted hand muscles and feel touch. Around this time he also became able to feed himself and grasp a pen to write. Two months later he could use scissors.
Within a year of the surgery, Zion could swing a baseball bat using both hands.
Meanwhile, scans revealed the boy's brain had developed pathways for control of hand movement and for carrying touch sensation signals from the hand back to the brain.
The report also documents a series of setbacks including eight rejections of the hands, which were managed with immunosuppression drugs, and some minor infections as well as some impairment to his transplanted kidney.
The researchers said caution must be taken when assessing the benefits and harms of such a procedure given the need for immunosuppression medication which carries risk for other conditions.
Dr Amaral added: "While functional outcomes are positive and the boy is benefiting from his transplant, this surgery has been very demanding for this child and his family."