# US 9,433,471 B2 · Tracked cartilage repair system

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- Number: US 9,433,471 B2
- Document ID: US9433471B2
- Status: Granted
- Kind: B2
- Application number: 14/160,729
- Filed: 2014-01-22
- Published: 2014-05-15
- Granted: 2016-09-06
- Earliest claimed: 2010-02-25
- Assignees: Zimmer, Inc.
- Applicants: Zimmer, Inc.
- Inventors: Joel Zuhars
- Web page: https://patentgrep.com/patent/US9433471B2

## CPC

- A61B 34/10: Computer-aided planning, simulation or modelling of surgical operations
- A61B 34/20: Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
- A61B 90/98: using electromagnetic means, e.g. transponders
- A61F 2/30756: {Cartilage endoprostheses (A61F2/3603 takes precedence)}
- A61F 2/30942: {for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques}
- A61B 17/16: Instruments for performing osteoclasis; Drills or chisels for bones; Trepans {(arthroscopic bone cutters A61B17/320016)}
- A61B 17/32002: {with continuously rotating, oscillating or reciprocating cutting instruments}
- A61B 90/90: Identification means for patients or instruments, e.g. tags
- A61B 2034/102: {Modelling of surgical devices, implants or prosthesis}
- A61B 2034/108: {Computer aided selection or customisation of medical implants or cutting guides}
- A61B 2034/2072: {Reference field transducer attached to an instrument or patient}
- B33Y 80/00: Products made by additive manufacturing
- Y10T 83/9372: Rotatable type
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A system and method for repairing an area of defective tissue reduces the removal of healthy tissue at the margins of the defect. During excision of diseased or damaged tissue, the system tracks the movement and function of a tissue resection tool within a monitored surgical space. This movement is continuously recorded to create a three-dimensional set of data points representative of the excised volume of tissue. This data set is then communicated to a custom implant forming device which creates a custom implant sized to fit the void created by the excision. The system and method of the present disclosure allows a surgeon to exercise intraoperative control over the specific shape, volume and geometry of the excised area. Moreover, the surgeon may utilize a “freehand” resection method to excise only that tissue deemed to be diseased and/or damaged, because the custom-formed implant will accommodate an irregularly-shaped resection volume.

## Claims

### Claim 1

A method of repairing a tissue defect in an anatomical structure, the method comprising: monitoring removal of a portion of the anatomical structure to create a void having a first shape, the portion including the tissue defect; determining a second shape corresponding to the first shape of the void; after determining a second shape, providing an implant having the second shape for placement within the void, the second shape generally matching the first shape; implanting the implant into the void; and resurfacing a surface of the implant to a desired contour; wherein monitoring removal of a portion of the anatomical structure includes monitoring a plurality of movements of a resection tool having an operative end while the operative end resects tissue from the anatomical structure.

### Claim 2 (depends on 1)

The method of claim 1, wherein determining a second shape corresponding to the first shape of the void includes using the plurality of movements to create a plurality of data points defining the second shape.

### Claim 3 (depends on 2)

The method of claim 2, wherein monitoring the plurality of movements includes detecting an emanated signal from a positional marker included in or coupled to the resection tool.

### Claim 4 (depends on 3)

The method of claim 3, wherein the emanated signal is indicative of at least one of a position and an orientation of the operative end.

### Claim 5 (depends on 4)

The method of claim 4, wherein resurfacing the implant includes:
collecting surface contour information of the anatomical structure before removal of a portion of the anatomical structure, the surface contour information creating a virtual articular surface model;
translating the surface contour information into surface contour tolerance values;
after the implant has been implanted, monitoring a second plurality of movements of the resection tool during removal of a portion of the articular surface, said monitoring creating a location signal representative of a location of the operative end of the resection tool;
iteratively comparing the location signal to the surface contour tolerance values to determine whether the operative end of the resection tool is in violation of the surface contour tolerance values; and
generating an implant resurfacing command if the operative end of the resection tool is in violation of the surface contour tolerance values.

### Claim 6 (depends on 4)

The method of claim 4, wherein providing an implant includes translating the plurality of data points into a plurality of implant forming commands and using the plurality of implant forming commands to form the implant.

### Claim 7 (depends on 6)

The method of claim 6, wherein translating the plurality of data points includes transmitting the emanated signal to a memory, processing the emanated signal to create a virtual three-dimensional volume representative of the plurality of data points, and translating the virtual three-dimensional volume into implant forming commands.

### Claim 8 (depends on 7)

The method of claim 7, wherein using the plurality of implant forming commands to form the implant includes transmitting the implant forming commands to a controller and using the controller to direct interactions between an implant forming system and an implant blank to replicate the virtual three-dimensional volume in the implant.

### Claim 9

A method of repairing a tissue defect in an anatomical structure, the method comprising:
monitoring removal of a portion of the anatomical structure to create a void having a first shape, the portion including the tissue defect, wherein monitoring removal of the portion of the anatomical structure includes
monitoring a plurality of movements of a resection tool having an operative end while the operative end resects tissue from the anatomical structure,
iteratively comparing the first shape of the void to a desired volumetric characteristic of the void to determine whether the operative end of the resection tool is at a desired boundary, wherein the desired volumetric characteristic is predefined and forms the desired boundary of the void, and
generating an anatomic shaping command if the operative end of the resection tool is at the desired boundary;
determining a second shape corresponding to the first shape of the void;
after determining a second shape, providing an implant having the second shape for placement within the void, the second shape generally matching the first shape; and
implanting the implant into the void.

### Claim 10 (depends on 9)

The method of claim 9, wherein monitoring removal of a portion of the anatomical structure includes detecting an emanated signal from a positional marker included in or coupled to the resection tool, wherein the emanated signal is indicative of at least one of a position and an orientation of the operative end.

### Claim 11 (depends on 10)

The method of claim 10, wherein the anatomic shaping command includes a command to cut power to the resection tool or a command to produce a visual indicator, an audio indicator, or a tactile indicator.

### Claim 12 (depends on 9)

The method of claim 9, wherein the resection tool is controlled by a robotic arm during resection of tissue from the anatomical structure.

### Claim 13 (depends on 9)

The method of claim 9, wherein monitoring a plurality of movements of a resection tool includes collecting data on an amount of power flowing to the operative end of the resection tool.

### Claim 14

A method of repairing a tissue defect in an anatomical structure, the method comprising:
monitoring removal of a portion of the anatomical structure to create a void having a first shape, the portion including the tissue defect and the monitoring removal of the portion of the anatomical structure includes monitoring a plurality of movements of a resection tool having an operative end while the operative end resects tissue from the anatomical structure, wherein the operative end includes a unique identifier readable by the resection tool, and wherein the identifier is sent to a computer automatically when the operative end is attached to the resection tool;
determining a second shape corresponding to the first shape of the void including using the plurality of movements to create a plurality of data points defining the second shape;
after determining a second shape, providing an implant having the second shape for placement within the void, the second shape generally matching the first shape; and
implanting the implant into the void.

### Claim 15 (depends on 14)

The method of claim 14, wherein the unique identifier includes a barcode, an RFID tag, or a magnet.

### Claim 16 (depends on 14)

The method of claim 14, wherein the resection tool is controlled by a robotic arm during resection of tissue from the anatomical structure.

### Claim 17 (depends on 14)

The method of claim 14, wherein monitoring a plurality of movements of a resection tool includes collecting data on an amount of power flowing to the operative end of the resection tool.

### Claim 18 (depends on 14)

The method of claim 14, wherein determining a second shape corresponding to the first shape of the void includes acquiring a data set representing changes of the position and orientation of the operative end while the operative end resects tissue and wherein the data set is stored within a memory of a signal conversion system.

### Claim 19 (depends on 18)

The method of claim 18, wherein a conversion software converts the data set into implant forming commands.