Patient-specific cutting guide for the shoulder

A method of preparing a glenoid of a shoulder joint of a patient for a shoulder arthroplasty procedure, the method comprising:

• positioning a first patient-specific contact surface of a base portion of a guide into contact with a first surface of the glenoid that forms a cavity, wherein the base portion of the guide has a throughbore extending therethrough;
• positioning a guide extension in contact with a first surface of a scapula of the patient such that the guide extension is located anterior to a coracoid process, the guide extension extending from the base portion of the guide and having a second patient-specific contact surface,
• wherein, when the first patient-specific contact surface is positioned on the first surface of the glenoid and the guide extension is positioned on the first surface of the scapula, the guide is engaged into position;
• wherein when positioning the first patient-specific contact surface of the base portion, the first patient-specific contact surface is keyed with the first surface of the glenoid;
• inserting a pin through the throughbore and into the first surface of the glenoid;
• removing the guide from the glenoid while the pin remains in the first surface of the glenoid;
• and
• drilling a recess in the first surface of the glenoid, the drilling being guided by the pin.