Orthopedic reamer for bone preparation, particularly glenoid preparation

An orthopedic milling machine comprising:

• an orthopedic guide pin including a bone engaging end and a free end opposite to the bone engaging end, a length of the guide pin including the bone engaging end;
• a milling burr including:
• a hub;
• wherein the burr is configured for rotation about an axis of the hub, the hub including:
• a bore adapted to receive an orthopedic guide pin, wherein the bore is centered on the axis of the hub and passes axially through the hub;
• a transverse slot that extends axially through the hub's length connecting a proximal end of the hub to a distal end of the hub and providing an opening to the bore;
• a milling body that extends transversely from the hub and consists of a crown portion spaced radially from the hub and connected to the hub by one or more radial lugs;
• and
• a counterweight portion that spaced radially from the hub and the milling body so as to be arranged diametrically opposite the crown a counterweight portion that extends transversely from the hub and arranged diametrically opposite the crown portion such that the bore and the transverse slot are arranged substantially at 90° to the axis of the hub between the crown portion of the milling body and the counterweight;
• and
• a sleeve adapted to be simultaneously coupled to the hub and engaged around the orthopedic guide pin to drive the burr around the axis of the hub, whereby the milling burr can be moved laterally toward the guide pin at any location along the length of the guide pin so that the guide pin passes through the transverse slot until the guide pin is positioned in the bore.

A method of preparing a bone, the method comprising:

• sliding a burr between a shoulder blade and a humeral head using a lateral approach until the burr is coaxial with a guide pin previously placed in the shoulder blade without needing to axially engage the burr from a proximal end of the guide pin, the burr including:
• a hub;
• wherein the burr is configured for rotation about an axis of the hub, the hub including:
• a bore adapted to receive an orthopedic guide pin, wherein the bore is centered on the axis of the hub and passes axially through the hub;
• a transverse slot that extends axially through the hub's length connecting a proximal end of the hub to a distal end of the hub and providing an opening to the bore;
• a milling body that extends transversely from the hub and consists of a crown portion spaced radially from the hub and connected to the hub by one or more radial lugs;
• and
• a counterweight portion that spaced radially from the hub and the milling body so as to be arranged diametrically opposite the crown portion such that the bore and the transverse slot are arranged substantially at 90° to the axis of the hub between the crown portion of the milling body and the counterweight;
• after sliding the burr between the shoulder blade and the humeral head, coupling the drive shaft with the hub;
• and
• driving the burr to prepare the bone.