A reamer for acetabular procedures comprises a hemispherical head portion, through-holes, a stem portion, a center hole, and a tool-engaging portion. The through-holes are bored through a shell portion of the hemispherical head portion. The stem portion extends from an inner peak portion of the hemispherical head portion and has a specific length. The center hole is bored through the stem portion and the shell portion of the hemispherical head portion. The tool-engaging portion is provided at an end portion of the stem portion and configured for engaging an external tool for spinning the reamer. A size of through-hole is proportional to a distance from the peak portion to the position of the specific through-hole. Each of the through-holes is for grinding a bone structure and removes the ground bone powder therethrough from an outside of the hemispherical head portion to an inside of the hemispherical head portion.
