Alignment Guides With Patient-Specific Anchoring Elements

Abstract

A method for preparing a bone of a joint during joint arthroplasty. The method includes mounting an alignment guide on the bone of a patient along an alignment direction. The method further includes anchoring the alignment guide into a cartilage of the bone using a plurality of patient-specific anchoring elements extending from an inner surface of alignment guide, each anchoring element having a patient-specific length extending between the inner surface and an end point of the corresponding anchoring element.

What is claimed is: 
     
         1 . A method for preparing a bone of a joint during joint arthroplasty comprising:
 mounting an alignment guide on the bone of a patient along an alignment direction; and   anchoring the alignment guide into a cartilage of the bone using a plurality of patient-specific anchoring elements extending from an inner surface of alignment guide, each anchoring element having a patient-specific length extending between the inner surface and an end point of the corresponding anchoring element.   
     
     
         2 . The method of  claim 1 , wherein the end points of the anchoring elements define a geometric envelope that traces an outer surface of the bone. 
     
     
         3 . The method of  claim 1 , wherein the anchoring elements are parallel to the alignment direction. 
     
     
         4 . The method of  claim 1 , further comprising customizing the plurality of patient-specific anchoring elements based on imaging of a particular patient's anatomy. 
     
     
         5 . The method of  claim 1 , wherein the inner surface is a three-dimensional patient-specific surface including a customized shape based on a multi-dimensional image of an outer cartilage surface of the bone of the patient and configured to nestingly mate to and be mounted on the outer cartilage surface of the bone of the patient in only one position. 
     
     
         6 . The method of  claim 1 , further comprising positioning the aligning guide such that the anchoring elements penetrate through an outer cartilage surface of the bone and penetrate through the outer bone surface of the bone to anchor the alignment guide on the bone of the patient. 
     
     
         7 . The method of  claim 6 , wherein each anchoring element includes a patient-specific cartilage-anchoring portion and a bone-anchoring portion, the cartilage-anchoring portion having first and second ends, the first end extending from the inner surface of the alignment guide, the bone-anchoring portion extending from a portion of the second end of the cartilage-anchoring portion. 
     
     
         8 . The method of  claim 1 , further comprising mounting and anchoring the alignment guide to a distal femoral bone. 
     
     
         9 . The method of  claim 1 , further comprising mounting and anchoring the alignment guide to a proximal tibial bone. 
     
     
         10 . A method for preparing a bone of a joint during joint arthroplasty comprising:
 mounting an alignment guide on an outer cartilage surface of an articular cartilage of an underlying bone of the patient;   anchoring the alignment guide on the patient's anatomy using a plurality of patient-specific anchoring elements extending from a cartilage-engaging surface of alignment guide;   penetrating the cartilage with cartilage-engaging portions of the anchoring elements, each cartilage-engaging portion having a length extending between first and second ends; and   penetrating an outer bone surface of the underlying bone with bone-engaging portions of the anchoring elements.   
     
     
         11 . The method of  claim 10 , further comprising abutting and mating the outer cartilage surface of the bone with shoulder surfaces of the cartilage-engaging portions of the anchoring elements. 
     
     
         12 . The method of  claim 10 , further comprising determining patient-specific lengths of the cartilage-engaging portions of the anchoring elements from the cartilage thickness at corresponding locations of the bone of the patient. 
     
     
         13 . The method of  claim 12 , further comprising determining the cartilage thickness from a three-dimensional computer image of the bone and articular cartilage reconstructed from medical scans of the patient during a preoperative plan for the patient. 
     
     
         14 . The method of  claim 10 , further comprising nestingly mating a three-dimensional patient-specific cartilage engaging surface of the alignment guide on the outer cartilage of the patient in only one position. 
     
     
         15 . The method of  claim 10 , wherein the inner surface is a three-dimensional patient-specific surface including a customized shape based on a multi-dimensional image of an outer cartilage surface of the bone of the patient and configured to nestingly mate to and be mounted on the outer cartilage surface of the bone of the patient in only one position. 
     
     
         16 . A method for preparing a bone of a joint during joint arthroplasty comprising:
 mounting an alignment guide on the bone of a patient along an alignment direction; and   positioning the aligning guide such that a plurality of patient-specific anchoring elements extending from an inner surface of the alignment guide penetrate through an outer cartilage surface of the bone and penetrate through an outer bone surface of the bone for anchoring the alignment guide on the bone of the patient, each patient-specific anchoring element having a patient-specific length extending between the inner surface and an end point of the corresponding anchoring element.   
     
     
         17 . The method of  claim 16 , wherein the inner surface is a three-dimensional patient-specific surface including a customized shape based on a multi-dimensional image of the outer cartilage surface and configured to nestingly mate to and be mounted on the outer cartilage surface in only one position. 
     
     
         18 . The method of  claim 16 , further comprising abutting and mating the outer cartilage surface of the bone with shoulder surfaces of cartilage-engaging portions of the anchoring elements. 
     
     
         19 . The method of  claim 16 , further comprising customizing the plurality of patient-specific anchoring elements based on imaging of the patient's own anatomy. 
     
     
         20 . The method of  claim 16 , further comprising determining patient-specific lengths of the cartilage-engaging portions of the anchoring elements from cartilage thickness at corresponding locations of the bone of the patient.