A reamer comprising a reamer body and a plurality of reamer blades, said reamer body comprising a shell comprising: - a shell sidewall having a convex exterior surface spaced from a concave interior surface by a shell thickness, wherein the shell extends from an apex to a lower shell edge, the shell being detachably connectable to a reamer shaft for rotational movement about a rotational axis that extends through the apex and is aligned perpendicular to an imaginary equatorial plane at the lower shell edge, and wherein a first imaginary bisecting plane and a second imaginary bisecting plane intersect the rotational axis and the imaginary equatorial plane offset 90 ° from each other; characterized by - a first slit through the shell sidewall thickness, the first slit extending from at or adjacent to the lower shell edge and toward the first imaginary bisecting plane, wherein the first slit is spaced clockwise from the second imaginary bisecting plane with respect to a view looking along the rotational axis toward the lower shell edge; - a second slit through the shell sidewall thickness, the second slit extending from at or adjacent to the lower shell edge and toward the first imaginary bisecting plane, wherein the second slit is spaced clockwise from the second imaginary bisecting plane with respect to the rotational axis, but on an opposite side thereof with respect to the first slit; and - a first reamer blade and a second reamer blade, - and wherein each blade comprises a blade sidewall extending from a proximal blade portion to a distal cutting portion, wherein the first and second reamer blades are received in the respective first and second slits with their respective distal cutting portions comprising a plurality of first and second cutting teeth extending outwardly from the convex exterior surface; - and the cutting teeth are angled in a direction of rotation such that when the reamer is rotated, bone and tissue is cut. - a shell sidewall having a convex exterior surface spaced from a concave interior surface by a shell thickness, wherein the shell extends from an apex to a lower shell edge, the shell being detachably connectable to a reamer shaft for rotational movement about a rotational axis that extends through the apex and is aligned perpendicular to an imaginary equatorial plane at the lower shell edge, and wherein a first imaginary bisecting plane and a second imaginary bisecting plane intersect the rotational axis and the imaginary equatorial plane offset 90 ° from each other; - a first slit through the shell sidewall thickness, the first slit extending from at or adjacent to the lower shell edge and toward the first imaginary bisecting plane, wherein the first slit is spaced clockwise from the second imaginary bisecting plane with respect to a view looking along the rotational axis toward the lower shell edge; - a second slit through the shell sidewall thickness, the second slit extending from at or adjacent to the lower shell edge and toward the first imaginary bisecting plane, wherein the second slit is spaced clockwise from the second imaginary bisecting plane with respect to the rotational axis, but on an opposite side thereof with respect to the first slit; and - a first reamer blade and a second reamer blade, - and wherein each blade comprises a blade sidewall extending from a proximal blade portion to a distal cutting portion, wherein the first and second reamer blades are received in the respective first and second slits with their respective distal cutting portions comprising a plurality of first and second cutting teeth extending outwardly from the convex exterior surface; - and the cutting teeth are angled in a direction of rotation such that when the reamer is rotated, bone and tissue is cut.