With the thumb floating and not functioning, how will the child use his hand? He will use his index and middle fingers to pinch, and with prolonged use of the index and middle fingers to pinch things, the child will not be able to bend his index finger, which is fine in small children, but will be very noticeable in older children. Therefore, it is necessary to save the floating thumb through surgery so that it can function. Currently there are two treatment options for floating bunions to save the fifth finger, one is to remove the metatarsal bone and the other is to remove the metacarpal bone. Metatarsal bone extraction is to transplant half of the third or fourth metatarsal bone of the foot (longitudinal) to the affected hand to rebuild the first metacarpal bone and the first carpometacarpal joint. However, metatarsal bone extraction will have some impacts, such as a certain degree of graft bone resorption, necrosis chances, and residual surgical scarring in the foot, and so on. Now we use the hemi-metacarpal bone graft reconstruction program, taking part of the child’s second metacarpal bone to reconstruct the first metacarpal bone, without moving the foot, the surgery is only performed in the hand. Compared to metatarsal bone removal, metacarpal bone removal does not affect the foot and the chance of bone resorption and necrosis is greatly reduced. Hemi-metacarpal bone graft reconstruction is a two-stage procedure, with the first stage being reconstruction of the skeleton, and after four to six months, a second stage of functional reconstruction is done to give the thumb function. After the surgery, the thumb function can be restored by about 70%, and the child can write and draw, hold chopsticks and spoons, hold larger cups of water, and hold small pellets, both fine activities and strength activities.