Patient-specific numerically controlled instrument

1. A method for preparing a bone of a joint of a patient comprising:

mounting a patient specific reference guide on a bone of a joint of a patient, the patient specific reference guide having a three-dimensional inner surface preoperatively configured to mate and closely nest to a corresponding surface of the bone only in one position, wherein mounting the patient specific reference guide on a bone of a joint of a patient includes mounting the reference guide on a femoral head surface of the patient, and wherein the reference guide is configured for mating with the femoral head surface of the patient;

coupling a housing of a numerically-controlled instrument to a connecting portion coupled to an outer surface of the reference guide;

automatically registering the numerically controlled instrument to the bone by coupling the housing to the reference guide and without intraoperative computer-aided navigation;

coupling a cutting tool to the housing;

guiding the cutting tool along a patient-specific tool path using the numerically-controlled instrument while the housing is mounted to the reference guide, the patient-specific tool path determined preoperatively and stored in the numerically-controlled instrument; and

preparing a portion of the bone using the cutting tool.

2. The method of claim 1 , wherein preparing the portion of the bone includes removing a femoral acetabular impingement defect from a femoral neck of the bone.

3. A method for preparing a bone of a joint of a patient comprising:

mounting a patient specific reference guide on a bone of a joint of a patient, the patient specific reference guide having a three-dimensional inner surface preoperatively configured from preoperative scans of the bone of the joint to mirror and mate with a corresponding surface of the bone only in one position;

coupling a guide connector of a housing of a miniaturized numerically-controlled instrument to a connecting portion coupled to an outer surface of the reference guide, the housing including the guide connector, a controller, a processor and a tool driver;

automatically registering the numerically controlled instrument to the bone by coupling the housing to the reference guide;

converting by the processor a patient-specific tool path to signals for the controller, the patient-specific tool path determined preoperatively and stored in the numerically-controlled instrument; removably coupling a cutting tool to the housing;

operating by the controller the tool driver from the signals; and

guiding the cutting tool along the patient-specific tool path using the numerically-controlled instrument while the housing is mounted to the reference guide.

4. The method of claim 3 , further comprising:

removing a femoral acetabular impingement defect with the cutting tool.

5. The method of claim 3 , further comprising:

removing a bony growth of a femoral neck with the cutting tool.

6. The method of claim 3 , further comprising:

preparing an acetabular socket of the joint for receiving an acetabular cup with the cutting tool.

7. The method of claim 3 , further comprising:

resurfacing a femoral head of the joint with the cutting tool.

8. The method of claim 3 , further comprising:

resurfacing a humeral head of the joint with the cutting tool.

9. The method of claim 3 , further comprising:

removing a defect of a femoral head of the joint with the cutting tool.

10. The method of claim 3 , wherein the reference guide is an annular ring and wherein mounting the patient specific reference guide on a bone of a joint of a patient further includes mating the annular ring to an annular area around a rim of the acetabulum of the patient.

11. The method of claim 10 , further comprising preparing the acetabulum of the patient for receiving an implant.

12. The method of claim 3 , wherein mounting the patient specific reference guide on a bone of a joint of a patient includes mounting the reference guide on a femoral head surface of the patient, and wherein the reference guide is a shell-like structure configured for mating with the femoral head surface of the patient.

13. A method for preparing a bone of a joint of a patient comprising:

mounting a patient specific reference guide on a bone of a joint of a patient, the patient specific reference guide having a three-dimensional inner surface preoperatively configured from preoperative scans of the bone of the joint to mirror and mate with a corresponding surface of the bone only in one position, the reference guide including a connecting portion;

coupling a housing of a miniaturized numerically-controlled instrument to the connecting portion of the reference guide, the housing including a controller, a processor and a tool driver;

automatically registering the numerically controlled instrument to the bone by coupling the housing to the inner surface of the reference guide;

processing and converting a patient-specific tool path to signals for the controller, the patient-specific tool path determined preoperatively and stored in the numerically-controlled instrument;

removably coupling a cutting tool to the housing;

controlling the tool driver from the signals; and

guiding the cutting tool along the patient-specific tool path using the numerically-controlled instrument while the housing is mounted to the reference guide.

14. The method of claim 13 , further comprising:

removing a femoral acetabular impingement defect with the cutting tool.

15. The method of claim 13 , further comprising:

removing a bony growth of a femoral neck with the cutting tool.

16. A method for preparing a bone of a joint of a patient comprising:

mounting a patient specific reference guide on a bone of a joint of a patient, the patient specific reference guide having a three-dimensional inner surface preoperatively configured to mate and closely nest to a corresponding surface of the bone only in one position, wherein mounting the patient specific reference guide on a bone of a joint of a patient includes mounting the reference guide on an acetabulum of the patient;

coupling a housing of a numerically-controlled instrument to a connecting portion coupled to an outer surface of the reference guide;

automatically registering the numerically controlled instrument to the bone by coupling the housing to the reference guide and without intraoperative computer-aided navigation;

coupling a cutting tool to the housing;

guiding the cutting tool along a patient-specific tool path using the numerically-controlled instrument while the housing is mounted to the reference guide, the patient-specific tool path determined preoperatively and stored in the numerically-controlled instrument; and

preparing a portion of the bone using the cutting tool.

17. The method of claim 16 , wherein the reference guide is an annular ring and wherein mounting the patient specific reference guide on a bone of a joint of a patient further includes mating the annular ring to an annular area around a rim of the acetabulum of the patient.

18. The method of claim 17 , wherein preparing the portion of the bone includes preparing the acetabulum of the patient for receiving an implant.

19. The method of claim 17 , wherein coupling the housing of a numerically-controlled instrument to a connecting portion coupled to an outer surface of the reference guide includes coupling the housing with a plurality of connecting adaptors coupled to the reference guide.