Orthopaedic planning systems and methods of repair

This disclosure relates to planning systems and methods. The planning systems and methods disclosed herein may be utilized for planning orthopaedic procedures to restore functionality to a joint, may include determining a contact area between an implant and a cortical area of an associated bone.

BACKGROUND

This disclosure relates to orthopaedic procedures and, more particularly, to systems and methods for planning the repair of bone defects and restoration of functionality to a joint.

Many bones of the human musculoskeletal system include articular surfaces. The articular surfaces articulate relative to other bones to facilitate different types and degrees of joint movement. The articular surfaces can erode or experience bone loss over time due to repeated use or wear or can fracture as a result of a traumatic impact. These types of bone defects can cause joint instability and pain.

Bone deficiencies may occur along the articular surfaces. Some techniques utilize a bone graft and/or implant to repair a defect adjacent the articular surfaces.

The surgeon may establish a surgical plan relating to preparation of a surgical site, selection of an implant, and placement of the implant along the surgical site. Surgical planning may include capturing an image of the surgical site and determining a position of an implant based on the image.

SUMMARY

This disclosure relates to planning systems and methods. The planning systems may be utilized for planning orthopaedic procedures to restore functionality to a joint, including determining a contact area between an implant and a cortical area of an associated bone.

A system for planning an orthopaedic procedure of the present disclosure may include a computing device including a processor coupled to a memory. The processor may be configured to execute a planning environment including a display module, a spatial module and a comparison module. The memory may be configured to store one or more implant models and one or more bone models. The spatial module may be configured to establish an outer perimeter and an inner perimeter along a first reference plane, and the inner and outer perimeters may be associated with respective inner and outer profiles of a cortical wall of the selected bone model. The display module may be configured to display in a first display window of a graphical user interface a selected one of the implant models and a selected one of the bone models relative to a first image plane. The comparison module may be configured to determine a cortical area and a contact area. The cortical area may correspond to an area between the inner perimeter and the outer perimeter along the first reference plane. The contact area may correspond to a first region of overlap between the selected implant model and the cortical area in which the selected implant model contacts the selected bone model along the first reference plane. The comparison module may be configured to cause the display model to display at least one indicator relating to the contact area in the graphical user interface.

A method of planning an orthopaedic procedure of the present disclosure may include selecting a bone model from a plurality of bone models by interacting with a graphical user interface, selecting an implant model from a plurality of implant models by interacting with the graphical user interface, displaying in a first display window of a graphical user interface a selected one of the implant models and a selected one of the bone models relative to a first image plane, determining an outer perimeter and an inner perimeter along a first reference plane, wherein the inner and outer perimeters may be respectively associated with inner and outer profiles of a cortical wall of the selected bone model, determining a cortical area and a contact area, wherein the cortical area may correspond to an area between the inner perimeter and the outer perimeter along the first reference plane, and the contact area may correspond to a first region of overlap between the selected implant model and the cortical area in which the selected implant model contacts the selected bone model along the first reference plane, and displaying in the first display window at least one indicator relating to the contact area.

A system for planning an orthopaedic procedure of the present disclosure may include a computing device including a processor coupled to a memory. The processor may be configured to execute a planning environment including a display module, a spatial module and a comparison module. The memory may be configured to store an implant model and a bone model. The spatial module may be configured to establish a perimeter along a reference plane, and the perimeter may be associated with a profile of a cortical wall of the bone model. The display module may be configured to display in a display window of a graphical user interface the implant model and the bone model relative to an image plane. The comparison module may be configured to determine a cortical area and a contact area, the cortical area bounded by the perimeter, and the contact area may correspond to a region of overlap between the implant model and a cortical area in which the implant model contacts the bone model along the reference plane.

DETAILED DESCRIPTION

This disclosure relates to surgical planning. The planning systems described herein may be utilized for orthopaedic procedures and may be utilized to create, edit, execute and/or review surgical plans. The surgeon may utilize the planning systems pre-operatively, intra-operatively and/or post-operatively. The planning systems and method disclosed herein may include determining a manner in which to resect a bone, and may also include determining placement of a selected implant relative the resection surface. The planning systems may determine a contact area between the implant and a cortical area of the bone along the resection surface. The planning systems may display or otherwise present the contact area in a manner that improves positioning of the implant, which may improve healing of the patient.

A system for planning an orthopaedic procedure according to an exemplary aspect of the present disclosure may include a computing device including a processor coupled to a memory. The processor may be configured to execute a planning environment including a display module, a spatial module and a comparison module. The memory may be configured to store one or more implant models and one or more bone models. The spatial module may be configured to establish an outer perimeter and an inner perimeter along a first reference plane, and the inner and outer perimeters may be associated with respective inner and outer profiles of a cortical wall of the selected bone model. The display module may be configured to display in a first display window of a graphical user interface a selected one of the implant models and a selected one of the bone models relative to a first image plane. The comparison module may be configured to determine a cortical area and a contact area. The cortical area may correspond to an area between the inner perimeter and the outer perimeter along the first reference plane. The contact area may correspond to a first region of overlap between the selected implant model and the cortical area in which the selected implant model contacts the selected bone model along the first reference plane. The comparison module may be configured to cause the display model to display at least one indicator relating to the contact area in the graphical user interface.

In some implementations, the comparison module may be configured to update the contact area in response to relative movement between the selected implant model and the selected bone model along the first reference plane.

In some implementations, the display module may be configured to set the first image plane to be parallel to the first reference plane.

In some implementations, the at least one indicator may include a visual contrast between the contact area and a remainder of the cortical area that excludes the contact area.

In some implementations, the spatial module may be configured to determine a bone area defined as an area surrounded by the outer perimeter along the first reference plane. The comparison module may be configured to determine a percentage of the contact area with respect to the bone area. The at least one indicator may be generated in response to the percentage of the contact area exceeding at least one predefined contact threshold.

In some implementations, the spatial module may be configured to establish a resection plane along the selected bone model. The resection plane may be defined by a resection angle. The display module may be configured to set the first reference plane to be coincident with the resection plane. The display module may be configured to set the first image plane to be parallel to the resection plane.

In some implementations, a volume of the selected implant model may be partially received in a volume of the selected bone model along the resection plane.

In some implementations, the comparison module may be configured to update the cortical area and the contact area in response to a change in the resection angle.

In some implementations, the graphical user interface may include a second display window. The display module may be configured to display in the second display window the selected implant model and the selected bone model relative to a second image plane. The second image plane may be transverse to the first image plane.

In some implementations, the spatial module may be configured to define a calcar region of the cortical area. The calcar region may extend through a calcar of a bone associated with the selected bone model. The comparison module may be configured to determine a second region of overlap between the calcar region and the first region of overlap. The at least one indicator may include a first indicator that identifies a portion of the first region of overlap that excludes the second region of overlap. The at least one indicator may include a second indicator that identifies the second region of overlap.

In some implementations, the first indicator and the second indicator may establish visual contrasts between each other and a remainder of the cortical area that excludes the contact area.

In some implementations, the spatial module may be configured to determine the outer perimeter in response to user interaction that defines a first set of points adjacent to the outer profile of the cortical wall. The spatial module may be configured to determine the inner perimeter in response to user interaction that defines a second set of points adjacent to the inner profile of the cortical wall.

In some implementations, the selected bone model may correspond to a bone associated with a joint.

A method of planning an orthopaedic procedure according to an exemplary aspect of the present disclosure may include selecting a bone model from a plurality of bone models by interacting with a graphical user interface, selecting an implant model from a plurality of implant models by interacting with the graphical user interface, displaying in a first display window of a graphical user interface a selected one of the implant models and a selected one of the bone models relative to a first image plane, determining an outer perimeter and an inner perimeter along a first reference plane, wherein the inner and outer perimeters may be respectively associated with inner and outer profiles of a cortical wall of the selected bone model, determining a cortical area and a contact area, wherein the cortical area may correspond to an area between the inner perimeter and the outer perimeter along the first reference plane, and the contact area may correspond to a first region of overlap between the selected implant model and the cortical area in which the selected implant model contacts the selected bone model along the first reference plane, and displaying in the first display window at least one indicator relating to the contact area.

In some implementations, the method may include updating the contact area in response to moving the selected implant model relative to the selected bone model.

In some implementations, the method may include selecting a resection angle to define a resection plane along the selected bone model. The method may include setting the first reference plane to be coincident with the resection plane. The method may include setting the first image plane to be parallel to the resection plane.

In some implementations, the method may include displaying in a second display window of the graphical user interface the selected implant model and the selected bone model relative to a second image plane. The second image plane may be transverse to the first image plane.

In some implementations, the method may include setting the second image plane to be perpendicular to the first image plane. The method may include positioning the selected implant model along the resection plane such that a volume of the selected implant model may be partially received in a volume of the selected bone model.

In some implementations, the method may include updating the determined cortical area and the determined contact area in response to changing the selected resection angle.

In some implementations, the method may include determining a bone area, wherein the bone area is defined as an area surrounded by the outer perimeter along the first reference plane. The method may include determining a percentage of the contact area with respect to the bone area. The method may include displaying the percentage of the contact area in the graphical user interface. The at least one indicator may include a first indicator and a second indicator. The method may include displaying the first indicator in response to the percentage of the contact area meeting at least one predefined contact threshold, but displaying the second indicator in response to the percentage of the contact area being below the at least one predefined contact threshold.

In some implementations, the method may include determining a second region of overlap between the contact area and a calcar region of the cortical area. The calcar region may extend through a calcar of a bone associated with the selected bone model. The method may include displaying a perimeter of the second region of overlap in the first display window. The method may include displaying a perimeter of a remainder of the contact area in the first display window that excludes the second region of overlap. The method may include displaying a perimeter of a remainder of the cortical area in the first display window that excludes the contact area.

In some implementations, the at least one indicator may include a first indicator and a second indicator. The method may include determining a cancellous area of the selected bone model. The cancellous area may correspond to an area along the first reference plane that is surrounded by the inner perimeter. The first region of overlap may be associated with a first weight, the second region of overlap may be associated with a second weight, the cancellous area may be associated with a third weight, and the first weight may be greater than the third weight but may be less than the second weight. The method may include determining a weighted value of the contact area according to the first, second and third weights. The method may include displaying the first indicator in the graphical user interface in response to the weighted contact area exceeding at least one predefined weighted contact threshold, but displaying the second indicator in the graphical user interface in response to the weighted contact area being below the at least one predefined weighted contact threshold.

In some implementations, the at least one indicator may include a third indicator and a fourth indicator. The method may include determining a bone density of the selected bone model along the contact area based on the weighted value of the contact area. The method may include displaying the third indicator in the graphical user interface in response to the bone density exceeding at least one predefined density threshold, but displaying the fourth indicator in the graphical user interface in response to the bone density being below the at least one predefined density threshold.

In some implementations, the method may include selecting a resection angle to define a resection plane along the selected bone model. The method may include setting the first reference plane to be coincident with the resection plane. The method may include setting the first image plane to be parallel to the resection plane. The method may include performing at least one of the following steps in response to the weighted contact area being below the at least one predefined weighted contact threshold: selecting another implant model from the plurality of implant models; changing the selected resection angle; moving the selected implant model along the resection plane; and/or rotating the selected implant model about an implant axis that extends through the resection plane.

In some implementations, the selected bone model may correspond to a bone associated with a joint.

In some implementations, the bone may be a humeral head of a humerus.

A system for planning an orthopaedic procedure according to an exemplary aspect of the present disclosure may include a computing device including a processor coupled to a memory. The processor may be configured to execute a planning environment including a display module, a spatial module and a comparison module. The memory may be configured to store an implant model and a bone model. The spatial module may be configured to establish a perimeter along a reference plane, and the perimeter may be associated with a profile of a cortical wall of the bone model. The display module may be configured to display in a display window of a graphical user interface the implant model and the bone model relative to an image plane. The comparison module may be configured to determine a cortical area and a contact area, the cortical area bounded by the perimeter, and the contact area may correspond to a region of overlap between the implant model and a cortical area in which the implant model contacts the bone model along the reference plane.

In some implementations, the comparison module may be configured to cause the display model to display an indicator relating to the contact area in the graphical user interface.

FIG.1illustrates an exemplary planning system20that may be utilized for planning surgical procedures. The system20may be used for planning orthopaedic procedures, including pre-operatively, intra-operatively and/or post-operatively to create, edit, execute and/or review surgical plans.

The system20may include a host computer22and one or more client computers24. The host computer22may be configured to execute one or more software programs. In some implementations, the host computer22is more than one computer jointly configured to process software instructions serially or in parallel.

The host computer22may be in communication with one or more networks such as a network26comprised of one or more computing devices. The network26may be a private local area network (LAN), a private wide area network (WAN), the Internet, or a mesh network, for example.

The host computer22and each client computer24may include one or more of a computer processor, memory, storage means, network device and input and/or output devices and/or interfaces. The input devices may include a keyboard, mouse, etc. The output device may include a monitor, speakers, printers, etc. The memory may, for example, include UVPROM, EEPROM, FLASH, RAM, ROM, DVD, CD, a hard drive, or other computer readable medium which may store data and/or other information relating to the planning techniques disclosed herein. The host computer22and each client computer24may be a desktop computer, laptop computer, smart phone, tablet, or any other computing device. The interface may facilitate communication with the other systems and/or components of the network26.

Each client computer24may be configured to communicate with the host computer22directly via a direct client interface28or over the network26. The client computers24may be configured to execute one or more software programs, such as a various surgical tools. The planning package may be configured to communicate with the host computer22either over the network26or directly through the direct client interface28. In another implementation, the client computers24are configured to communicate with each other directly via a peer-to-peer interface30.

Each client computer24may be operable to access and locally and/or remotely execute a planning environment32. The planning environment32may be a standalone software package or may be incorporated into another surgical tool. The planning environment32may provide a display or visualization of one or more bone models and related images and one or more implant models via one or more graphical user interfaces (GUI). Each bone model, implant model, and related images and other information may be stored in one or more files or records according to a specified data structure.

The system20may include at least one storage system34, which may be operable to store or otherwise provide data to other computing devices. The storage system34may be a storage area network device (SAN) configured to communicate with the host computer22and/or the client computers24over the network26, for example. In implementations, the storage system34may be incorporated within or directly coupled to the host computer22and/or client computers24. The storage system34may be configured to store one or more of computer software instructions, data, database files, configuration information, etc.

In some implementations, the system20is a client-server architecture configured to execute computer software on the host computer22, which is accessible by the client computers24using either a thin client application or a web browser executing on the client computers24. The host computer22may load the computer software instructions from local storage, or from the storage system34, into memory and may execute the computer software using the one or more computer processors.

The system20may include one or more databases36. The databases36may be stored at a central location, such as the storage system34. In another implementation, one or more databases36may be stored at the host computer22and/or may be a distributed database provided by one or more of the client computers24. Each database36may be a relational database configured to associate one or more bone models38and one or more implant models40to each other and/or a surgical plan42. Each surgical plan42may be associated with a respective patient. Each bone model38, implant model40and surgical plan42may be assigned a unique identifier or database entry. The database36may be configured to store data corresponding to the bone models38, implant models40and surgical plans42in one or more database records or entries, and/or may be configured to link or otherwise associate one or more files corresponding to each respective bone model38, implant model40and surgical plan42. Bone models38stored in the database(s)36may correspond to respective patient anatomies from prior surgical cases, and may be arranged into one or more predefined categories such as sex, age, ethnicity, defect category, procedure type, etc.

Each bone model38may include information obtained from one or more medical devices or tools, such as a computerized tomography (CT), magnetic resonance imaging (MRI) machine and/or X-ray machine, that obtains one or more images of a patient. The bone model38may include one or more digital images and/or coordinate information relating to an anatomy of the patient obtained or derived from the medical device(s). Each implant model40may include coordinate information associated with a predefined design. The planning environment32may incorporate and/or interface with one or more modeling packages, such as a computer aided design (CAD) package, to render the models38,40as two-dimensional (2D) and/or three-dimensional (3D) volumes or constructs.

The predefined design may correspond to one or more components. The implant models40may correspond to implants and components of various shapes and sizes. Each implant may include one or more components that may be situated at a surgical site including screws, anchors and/or grafts. Each implant model40may correspond to a single component or may include two or more components that may be configured to establish an assembly. Each bone model38and implant model40may correspond to 2D and/or 3D geometry, and may be utilized to utilized to generate a wireframe, mesh and/or solid construct in a display.

Each surgical plan42may be associated with one or more of the bone models38and implant models40. The surgical plan42may include one or more revisions to bone model38and information relating to a position of an implant model40relative to the original and/or revised bone model38. The surgical plan42may include coordinate information relating to the revised bone model and a relative position of the implant model40in predefined data structure(s). Revisions to each bone model38and surgical plan42may be stored in the database36automatically and/or in response to user interaction with the system20.

One or more surgeons and other users may be provided with a planning environment32via the client computers24and may simultaneously access each bone model38, implant model40and surgical plan42stored in the database(s)36. Each user may interact with the planning environment32to create, view and/or modify various aspects of the surgical plan42. Each client computer24may be configured to store local instances of the bone models38, implant models40and/or surgical plans42, which may be synchronized in real-time or periodically with the database(s)36. The planning environment32may be a standalone software package executed on a client computer24or may be provided as one or more services executed on the host computer22, for example.

FIG.2illustrates an exemplary planning system120for planning a surgical procedure. The system120may be utilized for various orthopaedic and other surgical procedures, such as an arthroplasty to repair a joint. The system120may be utilized in the placement of an implant, such as an implant incorporated into a shoulder prosthesis, for example. Although the planning systems and methods disclosed herein primarily refer to repair of a humerus during an anatomic or reverse shoulder reconstruction, it should be understood that the planning system120may be utilized in the repair of other locations of the patient and other surgical procedures including repair of a glenoid and other joints such as a wrist, hand, hip, knee or ankle, and including repair of fractures.

The system120may include a computing device144including at least one processor146coupled to memory148. The computing device144can include any of the computing devices disclosed herein, including the host computer22and/or client computer24ofFIG.1. The processor146may be configured to execute a planning environment132for creating, editing, executing and/or reviewing one or more surgical plans142during pre-operative, intra-operative and/or post-operative phases of a surgery.

The planning environment132may include at least a data module150, a display module152, a spatial module154and a comparison module156. Although four modules are shown, it should be understood that fewer or more than four modules may be utilized and/or one or more of the modules may be combined to provide the disclosed functionality.

The data module150may be configured to access, retrieve and/or store data and other information in the database(s)136corresponding to one or more bone model(s)138, implant model(s)140and/or surgical plan(s)142. The data and other information may be stored in one or more databases136as one or more records or entries158. In some implementations, the data and other information may be stored in one or more files that are accessible by referencing one or more objects or memory locations references by the records or entries158.

The memory148may be configured to access, load, edit and/or store instances of one or more bone models138, implant models140and/or surgical plans142in response to one or more commands from the data module150. The data module150may be configured to cause the memory148to store a local instance of the bone model(s)138, implant model(s)140and/or surgical plan(s)142which may be synchronized with records158in the database(s)136.

The display module152may be configured to display data and other information relating to one or more surgical plans142in at least one graphical user interface (GUI)162. The computing device144may be coupled to a display device160. The display module152may be configured to cause the display device160to display information in the user interface162. A surgeon or other user may interact with the user interface162via the planning environment132to create, edit, execute and/or review one or more surgical plans142.

Referring toFIG.3, with continuing reference toFIG.2, the user interface162may include one or more display windows164and one or more objects166. The objects166may include graphics such as menus, tabs and buttons accessible by user interaction, such as tabs166T, buttons166B,166R,166S,166V, drop-down lists166L, and directional indicator166D. Geometric objects including selected bone model(s)138and implant model(s)140and other information relating to the surgical plan142may be displayed in one or more of the display windows164.

The implant model140may include one or more components. For example, the implant model140may include at least a first component140A and a second component140B coupled to the first component140A to establish an assembly. The first component140A may be configured to be at least partially received in a volume of a selected one of the bone models138. The second component140B may have an articulation surface dimensioned to mate with an articular surface of an opposed bone or implant.

The display windows164may include first, second and third display windows164-1,164-2,164-3. Although three display windows164are illustrated inFIG.3, it should be understood that fewer or more than three display windows164can be utilized in accordance with the teachings disclosed herein.

The first, second and third display windows164-1,164-2,164-3may be associated with respective first, second and third image planes IP1, IP2, IP3(shown in dashed lines for illustrative purposes). The first, second and/or third image planes IP1, IP2, IP3may be substantially perpendicular or otherwise transverse to each other.

The display module152may be configured to display in the first, second and third display windows164-1,164-2,164-3a selected one of the one or more bone models138and a selected one of the one or more implant models140relative to the respective image planes IP1, IP2, IP3. The display module152may be configured such that the selected bone model138and/or selected implant model140may be selectively displayed and hidden (e.g., toggled) in one or more of the display windows164in response to user interaction with the user interface162, which may provide the surgeon with enhanced flexibility in reviewing aspects of the surgical plan142.

The display module152may be configured to display 2D representation(s) of the selected bone model138and/or selected implant model140in the first and/or second display windows164-1,164-2. The surgeon may interact with the respective display windows164-1,164-2or another portion of the user interface162to move the selected bone model138and/or selected implant model140in 2D space (e.g., up, down, left, right). The image planes P1and/or P2may be locked to a single respective 2D perspective, as illustrated inFIG.3. In other implementations, the display module152may be configured to display 3D representation(s) of the selected bone model138and/or selected implant model140in the first and/or second display windows164-1,164-2.

The selected bone model138may correspond to a bone associated with a joint, such as a humerus as illustrated inFIG.3. The display module152may be configured to display a sectional view of the selected bone model138and/or selected implant model140in the first viewing window164-1. The sectional view may be presented as an image of the bone associated with the selected bone model138. The display module152may be configured to set the first image plane IP1to be parallel to the sectional view. An orientation of the sectional view may be predefined or may be specified in response to user interaction with the user interface162.

The spatial module154may be configured to establish a resection plane R1along the selected bone model138(R1shown in dashed lines in window164-1for illustrative purposes). A volume of the selected implant model140may be at least partially received in a volume of the selected bone model138along the resection plane RE The resection plane R1may be defined by a resection angle α, as illustrated inFIG.4. The resection angle α may be defined with respect to an angle between the resection plane R1and a longitudinal axis A of a bone B associated with the selected bone model138. The spatial module154may be configured to cause the display module152to display an excised portion of the selected bone model138to be displayed in the first display window164-1in a different manner than a remainder of the bone model138on an opposed side of the resection plane R1, such as a relatively darker shade as illustrated by the humeral head inFIG.3. In other implementations, the excised portion may be hidden from display in the first display window164-1. The spatial module154may determine the excised portion by comparing coordinates of the bone model138with respect to a position of the resection plane R1, for example.

The display module152may be configured to set the second image plane IP2of the second display window164-2to be parallel to a first reference plane REF1. The display module152may be configured to set the first reference plane REF1to be coincident with the resection plane RE Arranging the second display window164-2such that a viewpoint of the surgeon is substantially normal to the resection plane R1may provide improved visualization and positioning of the selected implant model140relative to a resected surface of the selected bone model138.

The user interface162may arranged in one or more tabs166T. The surgeon may interact with each of the tabs166T to specify various aspects of a surgical plan142. For example, the surgeon may select a first tab166T-1to view or specify aspects of the surgical plan142for one portion of a joint, such as a glenoid, and may select a second tab166T-2to view or specify aspects of the surgical plan142for another portion of the joint, such as a humerus, as illustrated inFIG.3.

The user may interact with a first set of menu items166M-1associated with the first display window164-1to select and specific various aspects of an implant model140from the database136(FIG.2). For example, the user may interact with the drop-down lists166L in the first set of menu items166M-1to specify implant type, resection angle and implant size. The resection angle menu item may be associated with the resection plane R1, which may be displayed as being substantially perpendicular to the first image plane IP1.

The user may interact with a set of buttons166R to change (e.g., increase or decrease) the resection angle. The user may interact with a set of buttons166S adjacent the selected implant model140to change (e.g., increase or decrease) a size of a component of the selected implant model140. The sets of buttons166R,166S may be overlaid onto the first display window164-1.

The surgeon may interact with a second set of menu items166M-2associated with the second display window164-2to specific various aspects of the selected implant model140. For example, the user may interact with the directional indicator166D to move a portion of the selected implant model140in different directions (e.g., up, down, left, right) relative to the second image plane IP2. In some implementations, the surgeon may drag the selected implant model140to a desired position in the second display window164-2utilizing a mouse, and may utilize the directional indicator166D to more finely tune the position of the selected implant model140. The surgeon may interact with one or more drop-down lists166L in the second list of menu items166M-2to specify a type and/or size of a component of the selected implant model140.

The display module152may be configured to display a 3D representation of the selected bone model138and/or selected implant model140in the third display window164-3. The surgeon may interact with the third display window164-3or another portion of the user interface162to move the selected bone model138and/or selected implant model140in 3D space. In other implementations, the display module152may be configured to display a 2D representation of the selected bone model138and/or selected implant model140in the third display window164-3.

The surgeon may interact with a third set of menu items166M-3associated with the third display window164-3to specific various aspects of the selected bone model138and/or selected implant model140. For example, the surgeon may interact with one or more drop-down lists166L in the third set of menu items166M-3to selectively display and hide components of the selected implant model140. The user may interact with one or more buttons166V in the third list of menu items166M-3to toggle between a volume of previous and revised (e.g., resected) states of the selected bone model138.

The planning environment132may be configured such that changes in one of the display windows164are synchronized with each of the other windows164. The changes may be synchronized between the display windows164automatically and/or manually in response to user interaction.

The surgeon may interact with the user interface162to evaluate implant placement relative to different resection angles for a selected bone model138.FIGS.5A-5Cillustrate exemplary resections of the bone B ofFIG.4relative to different resection angles. Each resection angle is illustrated by a respective bone model138-1to138-5, which may correspond to the same bone B. Bone models138-1to138-5may be associated with respective resection angles of 145, 140, 135, 130 and 125 degrees and a corresponding resection plane R1, for example.FIG.5Amay correspond to a side view of the respective bone models138-1to138-5.FIG.5Bmay correspond to a view of the respective bone models138-1to138-5parallel to the respective resection planes R1(seeFIGS.5A and5C).FIG.5Cmay correspond to a view of the respective bone models138-1to138-5parallel to the respective resection planes R1, with outer perimeters138PO-1to138PO-5of the respective bone models138-1to138-5and perimeters140P-1to140P-5of the respective implant models140shown. It should be understood that the arrangements ofFIGS.5A-5Care exemplary and other arrangements may be utilized in accordance with the teachings disclosed herein. As illustrated byFIGS.4and5C, a contour of the bone B associated with the bone model138may vary along a length and circumference of the bone B and may therefore have different surface areas and perimeter geometries along the respective resection plane R1.

FIG.6Aillustrates an exemplary bone B resected along a resection plane R1and aspects of the bone model138. Resection of the bone B along the resection plane R1exposes cortical bone B1and cancellous bone B2. The cortical bone B1may comprise substantially hard and dense bone tissue, whereas the cancellous bone B2may comprise relatively porous, spongy bone tissue, as illustrated inFIG.6B. The cortical bone B1may establish a cortical wall WC that surrounds the cancellous bone B2.

The spatial module154may be configured to establish or determine at least one perimeter of a bone B associated with the respective bone model138, such as an inner perimeter138PI and/or outer perimeter138PO. The spatial module154may be configured to establish or determine the inner perimeter138PI and/or outer perimeter138PO along a first reference plane REF1(shown in dashed lines for illustrative purposes). The first reference plane REF1may correspond to the resection plane R1(FIG.3). The inner perimeter138PI and outer perimeter138PO may be associated with respective inner and outer profiles of the cortical wall WC a bone associated with the selected bone model138. The cortical wall WC may correspond to or substantially approximate a cortical wall established by cortical bone tissue C1of the bone B. The cortical wall WC may surround a cancellous region CR. The cancellous region CR may correspond to or substantially approximate a region established by cancellous bone tissue C2of the bone B.

Various techniques may be utilized to determine at least one perimeter associated with a profile of the cortical wall WC of a bone B and the respective bone model138, such as the inner perimeter138PI and/or outer perimeter138PO. The spatial module154may be configured to establish at least one perimeter along the reference plane REF1, including the inner perimeter138PI and/or outer perimeter138PO, to establish a cortical area CA1. The cortical area CA1may correspond to an area between the inner perimeter138PI and outer perimeter138PO along the first reference plane REF1.

In some implementations, the spatial module154may be configured to execute one or more edge detection algorithms to determine the inner perimeter138PI and/or outer perimeter138PO that respectively approximate inner and outer boundaries of the cortical wall WC. Edge detection algorithms are known, and generally determine one or more edges in a digital image based gradients established between adjacent pixels in the image. However, utilizing edge detection techniques in accordance with the teachings disclosed herein is not known. The spatial module154may be configured to determine the inner and outer boundaries of the cortical wall WC based on gradients established by the cortical bone B1and cancellous bone B2in the respective image, as illustrated byFIG.6A. One would understand how to program the spatial module154to execute various edge detection algorithms.

In some implementations, the inner perimeter138PI and/or outer perimeter138PO of the respective bone model138is based on one or more predetermined values. Referring toFIG.7A, with continuing reference toFIG.2, a predefined thickness T may be assigned to a bone model238during configuration of the system20or manually by the surgeon by interaction with the user interface162. The predefined thickness T may be set based on a statistical analysis of data corresponding to a sample population of one or more prior surgical cases stored in the database136. For example, an outer perimeter238PO of a cortical wall WC may be determined utilizing one or more edge detection techniques.

The spatial module154may be configured to apply the predefined thickness T to the outer perimeter238PO to establish an inner perimeter238PI. The inner perimeter238PI may follow a contour of the outer perimeter238PO according to the predefined thickness T and approximates a boundary between the cortical wall WC and the cancellous bone B2(FIGS.6A-6B). The predefined thickness T may be stored in the respective surgical plan142and may be changed in response to user interaction with the user interface162to adjust the inner perimeter238PI and/or outer perimeter238PO. The various parameters disclosed herein may be updated in response to a change in predefined thickness T. The surgeon may change a value of the predefined thickness T based on various factors, such as one or more images and other information presented via the user interface162and an evaluation of the surgical case.

In some implementations, the surgeon may interact with the user interface162to approximate the inner and/or outer boundaries of the cortical wall WC. Referring toFIG.7B, with continuing reference toFIG.2, the spatial module154may be configured to determine an outer perimeter338PO of a bone model338in response to user interaction that defines a first set of points PO adjacent to an outer profile of the cortical wall WC. The spatial module154may be configured to determine an inner perimeter338PI of the bone model338in response to user interaction that defines a second set of points PI adjacent to an inner profile of the cortical wall WC.

The surgeon may interact with the one of the display windows164of the user interface162, such as the second display window164-4(FIG.3), to position the sets of points PI and/or PO relative to an image of the bone B. The spatial module154may be configured to interconnect the set of points PI and/or PO to establish the inner perimeter338PI and/or outer perimeter338PO of the bone model338. The inner perimeter338PI and/or outer perimeter338PO may approximate the inner and/or outer boundaries of the cortical wall WC. Various techniques may be utilized to interconnect the sets of points PI and/or PO, including linear line segments and best-fit techniques utilizing one or more polynomial relationships, for example. The exemplary techniques disclosed herein may be combined to determine the boundaries of the cortical wall WC of a respective bone B.

Referring toFIG.8, with continuing reference toFIG.2, the comparison module156may be configured to determine one or more relationships between a selected bone model438and a selected implant model440, including a cortical area CA1and contact area CA2. The cortical area CA1may be bounded by at least one perimeter. For example, the cortical area CA1may correspond to an area between an inner perimeter438PI and outer perimeter438PO along a first reference plane REF1. The cortical area CA1may be bounded by the inner perimeter438PI and outer perimeter438PO. The first reference plane REF1may be extend along the resection plane R1. The contact area C2may correspond to a first region of overlap OR1between the selected implant model440and the cortical area CA1in which the selected implant model440contacts the selected bone model438along the first reference plane REF1.

In some implementations, the spatial module154may be configured to determine a bone area BA defined as an area surrounded by the outer perimeter438PO along the first reference plane REF1. The comparison module156may be configured to determine a percentage of the contact area CA2with respect to the bone area BA. The comparison module156may be configured to cause the display module152to generate at least one indicator in response to the percentage of the contact area CA2exceeding at least one predefined contact threshold, as illustrated by indicator PI inFIG.12. The indicator PI may include various states, such as an UP arrow indicating that the predefined contact threshold(s) are met and a DOWN arrow indicating that the predefined contact threshold(s) are not met. Other example indicators may include a color coding status and a value of the percentage of the contact area CA2, as illustrated by indicator PV inFIG.12.

The comparison module156may be configured to update the determined cortical area CA1and/or contact area CA2in response to changes in the surgical plan142, such as selection of a different implant model440and changes in a geometry of the selected bone model438. For example, the comparison module156may be configured to update the contact area CA2in response to relative movement between the selected implant model440and the selected bone model438along the first reference plane REF1. The surgeon may interact with the user interface162to cause the selected implant module440to move in a direction DIR1, as illustrated by implant model440′ inFIG.9. The comparison module156may be configured to determine a cortical area CA1′ and contact area CA2′ associated with the change in position of the implant model440′. The cortical area CA1′ associated with the bone model438′ may be equal to the cortical area CA1associated with the bone model438ofFIG.8, but the contact area CA2′ associated with the implant model440′ may differ from the contact area CA2associated with the implant module440due to the change in position.

The comparison module156may be configured to determine the contact area CA2for different resection angles (α). For example, the surgeon may interact with the user interface162(FIG.2) to change (e.g., increase or decrease) the resection angle (α) to cause a change in orientation of the resection plane R1associated with the bone model438ofFIG.8, as illustrated by modified bone model538inFIG.10. The first reference plane REF1may be updated in response to the change in the resection angle (α).

The spatial module154may be configured to adjust a position of the selected implant model540relative to the modified bone model538in response to the change in resection angle (α), as illustrated inFIG.10. The comparison module156may be configured to determine the cortical area CA1and contact area CA2associated with the change in the resection angle (α). The cortical area CA1associated with the bone model438ofFIG.8may differ from the cortical area CA1associated with the modified bone model538ofFIG.10due to a profile of the respective bone. Accordingly, the contact area CA2associated with the bone model438may differ from the contact area CA2associated with the bone model538due to the change in the resection angle (α). One would understand how to program the comparison module156with logic to determine areas including the cortical area CA1and contact area CA2.

Referring toFIG.11, with continuing reference toFIG.2, the comparison module156may be configured to cause the display module152to display at least one or more indicators relating to a contact area CA2in a graphical user interface (GUI)662. The contact area CA2may be associated with a selected bone model638and a selected implant model640.

Referring toFIG.12, with continuing reference toFIG.11, the indicators may include a visual contrast between the contact area CA2and a remainder of the cortical area CA1that excludes the contact area CA2. The contact area CA2may be shown in a different shade and/or color than the remainder of the cortical area CAE The visual contrast is shown as hatching inFIGS.11-12for illustrative purposes. The contact area C2may establish a first region of overlap OR1between the selected implant model640and the cortical area CA1in which the selected implant model640contacts the selected bone model638along a first reference plane REF1.

The display module152may be configured to cause the user interface662to identify different portions of the contact area CA2using various techniques. The spatial module154may be configured to define a calcar region RCAL of the cortical area CAE The calcar region RCAL may extend through a calcar of a bone associated with the selected bone model638, such as a humerus. The calcar region RCAL may be defined by a calcar arc. The calcar arc may correspond to an arc passing through a point PC. The point PC may be established along a calcar of a humerus, as illustrated inFIG.11. The calcar arc may be defined by a calcar angle (β). The calcar angle (β) may be a predefined value or may be set by the user through interaction with the user interface662. The calcar angle (β) may extend less than or equal to approximately 180 degrees along the cortical area CA1between boundaries BR1, BR2. Each boundary BR1, BR2may be established with respect to the longitudinal axis A of the bone model638. In some implementations, the user may set the calcar angle (β) by moving boundary indicators BI1, BI2in the second display window664-2about the longitudinal axis A to set a position of the respective boundaries BR1, BR2. The disclosed techniques may allow the surgeon to vary the calcar region RCAL based on evaluating the bone quality and other conditions of the surgical site, which provides an improvement over prior systems by presenting detailed refinements in the determined contact area CA2and isolated subregions of interest based on feedback from the surgeon.

Various techniques may be utilized to establish a position of the point PC. The surgeon may interact with the user interface662to set a position of one or more points such as points PA, PB, PC to establish an elliptical object YC relative to the bone model638, as illustrated inFIG.11. The elliptical object YC may be a “Youderian” circle that characterizes an anatomy of a bone relative to a specified resection plane RE The user may interact with the user interface662to establish one or more points along the resection plane R1include the points PA, PC. The user may interact with the user interface662to establish one or more points adjacent the cortical wall WC, such as point PB. The spatial module154may be configured to establish and dimension a respective Youderian circle YC along the points PA, PB and/or PC.

The comparison module156may be configured to divide the first region of overlap OR1between two or more sub-regions and cause the display module152to display the sub-regions distinctly from each other in the user interface662. The comparison module156may be configured to determine a second region of overlap OR2between the calcar region RCAL and the first region of overlap OR1. A portion of the first region of overlap OR1that excludes the second region of overlap OR2may define a first subregion SR1of the first region of overlap OR1. The second region of overlap OR2may define as a second subregion SR2of the first region of overlap OR1. Various techniques can be utilized to determine the subregions SR1, SR2, including comparing the coordinate spaces of the first region of overlap OR1, second region of overlap OR2and calcar region RCAL relative to each other to determine overlapping and non-overlapping regions.

The comparison module156may be configured to cause the display module152to display a first indicator I1that identifies the first subregion SR1and a second indicator I2that identifies the second subregion SR2. In some implementations, the first indicator I1and second indicator I2may be textual objects. In other implementations, the first indicator I1and second indicator I2may establish visual contrasts between the respective first and second subregions SR1, SR2and a remainder of the cortical area CA1that excludes the contact area CA2, as illustrated inFIG.12. The comparison module156may be configured to cause the display module152to display a third indicator I3that identifies the remainder of the cortical area CA1that excludes the contact area CA2.

The first indicator I1and second indicator I2may be displayed in a different shade and/or color than each other and/or the third indicator I3. The visual contrast between indicators I1, I2is shown as different hatching inFIG.12for illustrative purposes. The indicator I3omits any hatching inFIG.12for illustrative purposes. The comparison module156may be configured to cause the display module152to update the indicators I1, I2, I3in response to change(s) relating to the selected bone model638and/or selected implant model640, such as movement of implant model640′ as illustrated by indicators I1′, I2′, I3′ inFIG.13. The disclosed techniques, including separately identifying the subregions SR1, SR2of the contact area CA2, provides an improvement over prior systems by conveying an enhanced representation of a relationship of the contact area CA2with respect to the cortical area CA1of the respective bone B and selected resection parameters. The surgeon may interact with the user interface162to tailor the surgeon plan142in an iterative manner based on this enhanced representation, which may improve efficiency in pre-operative planning, reduce inter-operative time that may otherwise be caused by changes to the surgical plan, and improve the surgical outcome for the patient based on a selection of parameters that more closely aligns with a relationship between the selected implant and an anatomy of the patient including bone quality and geometry along a resected surface.

The cortical coverage parameter668A may be defined as a value of the contact area CA2between the inner perimeter638PI and outer perimeter638PO along the resection plane R1and may be indicative of a portion of an implant associated with the selected implant model640that may be supported by cortical bone along the cortical wall WC.

The cancellous coverage parameter668B may be defined as a value of the contact area CA2surrounded by the inner perimeter638PI and may be indicative of a portion of an implant associated with the selected implant model640that may be supported by the cancellous bone. The cortical coverage parameter668A and cancellous coverage parameter668B may be expressed in units of cm{circumflex over ( )}2, for example.

The calcar arc coverage parameter668C may be defined as a portion of the calcar angle (β) of the calcar arc in which the contact area CA2is established along the calcar region RCAL. The value may be less than or equal to the calcar angle (β) of the calcar arc.

The bone density parameter668D may be defined as an average density of the respective bone along the contact area CA2, which may be expressed in units of gram/cm{circumflex over ( )}3, for example. Various techniques may be utilized to determine or approximate the bone density parameter668D. For example, a first predefined density value may be defined for cortical bone, and a second, different predefined density value may be defined for cancellous bone. The calcar region CR may comprise relatively more dense/strong bone tissue than other portions of the cortical wall. In some implementations, the second region of overlap OR2associated with the calcar region CR may be assigned a different (e.g. greater) predefined density value than a predefined density value associated with a remainder of the contact area CA2along the cortical wall WC. Each bone model138may include one or more predefined bone density values associated with or assigned to respective portions of a volume of the bone model138. For example, each coordinate of the bone model138may be assigned a respective bone density value. The bone density values may be the same or may differ for the volume of the bone model138. The comparison module156may be configured to calculate the bone density parameter668D based on a product of an area of the second region of overlap OR2and the respective predefined density value.

Various techniques can be utilized to determine the weighted contact area parameter668E. In some implementations, the spatial module154is configured to determine a cancellous area of the selected bone model638. The cancellous area may correspond to an area of cancellous bone B2(FIG.6A) along the first reference plane REF1that is surrounded by the inner perimeter638PI, as illustrated by the cancellous region CR. The first region of overlap OR1corresponding to the contact area CA2may be assigned or otherwise associated with a first weight. The second region of overlap OR2between the contact area CA2and calcar region RCAL may be assigned or otherwise associated with a second weight. The cancellous area corresponding to the cancellous region CR may be assigned or otherwise associated with a third weight. The first weight may be greater than the third weight but may be less than the second weight. For example, the second weight may be assigned a multiple of 1.5, the first weight may be assigned a multiple of 1, and the third weight may be assigned a multiple of 0.5. The comparison module156may be configured to determine a value of the weighted contact area parameter668E associated with the contact area CA2according to the first, second and third weights. The comparison module156may be configure to determine a value of the bone density parameter668D based on the value of the weighted contact area parameter668E.

The comparison module156may be configured to update the parameters668A-668E in response to changes relating to the selected bone model638and/or selected implant model640. For example, the comparison module156may be configured to update the parameters668A-668E in response movement of the selected implant model640, as illustrated by parameters668A′-668E′ inFIG.13.

The comparison module156may be configured to cause the display module152to display one or more indicators I3-I7associated with the parameters in the graphic668. For example, each indicator I3-I7may include a color-coded box based a predefined threshold associated with the respective parameter668A-668E. Each color-coded box may include one or more states. For example, a first color (e.g., green) may indicate that a value of the respective parameter668A-668E meets the predefined threshold, and a second color (e.g., red) may indicate that the value of the respective parameter668A-668E does not meet the predefined threshold. The comparison module156may be configured to cause the display module152to change the state of one or more of the indicators I3-I7in response to the changes relating to the selected bone model638and/or selected implant model640.

The surgeon may evaluate the indicators I3-I7and values of the various parameters668A-668E to revise the respective surgical plan142(FIG.2). For example, the surgeon may evaluate a quality of the bone including the value of the bone density parameter668D to values of the cortical coverage parameter668A, cancellous coverage parameter668B, calcar arc coverage parameter668C and/or weighted contact area parameter668E. The surgeon may determine that a desired value of the bone density parameter668D may or may not be suitable for a particular patient, even though a value of the surface area of the bone along the reference plane REF1and/or a value of the contact area CA2may be sufficient. The surgeon may interact with the user interface662to approach or meet the desired value of the bone density parameter668D, such as changing the specified resection angle (α) and/or resection plane R1, moving the selected implant model640relative to the resection plane R1, and/or selected another implant model140from the database136(FIG.2). For example, the surgeon may decrease the resection angle (α) to provide relatively more support to the selected implant model140. The surgeon may approve a surgical plan142having a value of the cortical coverage parameter668A that exceeds a predefined threshold, even though a value of the cancellous coverage parameter668B is below another predefined threshold, for example. The techniques disclosed herein may therefore provide the surgeon with an additional number of options in implant and surgical technique selection to improve the surgical outcome.

The user interface662may include at least one button666BR (FIG.12) that may be selected to present literature to the surgeon in assisting the surgeon in making the various selections and modifications to the surgical plan142. The literature may include a relative portion of a user manual explaining aspects of the indicators I1-7and respective parameters668A-668E and techniques for causing changes in the respective values to achieve a desired outcome. The literature presented to the user in response to selection of the button666BR may be based on values of the parameters668A-668E meeting various criteria, such as being below (or above) predetermined thresholds.

FIG.14illustrates an exemplary method of planning an orthopaedic procedure in a flowchart780. The method may be utilized pre-operatively, intra-operatively and/or post-operatively to create, edit, execute and/or review a respective surgical plan. The method may be utilized to perform an arthroplasty for restoring functionality to shoulders and other joints. Although the method780primarily refers to implants for repair of a defect in a humerus during a shoulder reconstruction, it should be understood that the method and disclosed implants may be utilized in other locations of the patient and other surgical procedures, such as the glenoid or any other location disclosed herein. The method780can be utilized with any of the planning systems disclosed herein. Fewer or additional steps than are recited below could be performed within the scope of this disclosure, and the recited order of steps is not intended to limit this disclosure. Reference is made to the planning systems120,620for illustrative purposes.

Referring toFIGS.2-3, with continuing reference toFIG.14, a bone model(s)138may be selected from one or more bone models138by interacting with a graphical user interface162at step780A. An implant model140may be selected from one or more implant models140by interacting with the user interface162at step780B. Available bone models138and implant models140in the database(s)136may be presented in one or more lists in the user interface162that may be selected in response to user interaction, for example. The selected bone model138may correspond to a bone associated with a joint, such as a humeral head of a humerus as illustrated inFIG.3.

Referring toFIGS.11and12, with continuing reference toFIG.14, a selected one of the one or more implant models640and a selected one of the one or more bone models638may be initially positioned and displayed in one or more windows664of the user interface662at step780C. Each selected bone model638and selected implant model640may be displayed in the display windows664-1,664-2and664-3according to any of the techniques disclosed herein, including different orientations and 2D/3D views. Each selected bone model638and selected implant model640may be displayed in the display window664-2relative to the viewing plane IP2.

The selected implant model640may be positioned relative to the selected bone model638at step780D. For example, the selected implant model640may be moved from the position illustrated inFIG.12to a position of the selected implant model640′ inFIG.13. A position of the selected implant model640may be adjusted in one or more iterations and prior to, during and/or subsequent to any of the steps of method780.

One or more resection parameters may be set at step780E. The resection parameters may include a resection angle (α) and/or resection plane R1associated with the resection angle (α) (seeFIG.4). The resection parameters may be stored in the respective surgical plan142(FIG.2). Step780E may include selecting a resection angle (α) to define a resection plane R1along the selected bone model638. Step780E may include setting the first reference plane REF1to be coincident with the resection plane R1. Step780E may include setting the image IP2plane of the respective window664-2to be parallel to the resection plane R1, as illustrated inFIG.12.

Step780E may include setting the first image plane IP1of the first display window664-1to be perpendicular to the second image plane IP2of the second display window664-2, as illustrated byFIG.11. Step780C and/or step780D may include positioning the selected implant model640along the resection plane R1such that a volume of the selected implant model640is partially received in a volume of the selected bone model638, as illustrated inFIG.11.

At step780F a cortical area CA1associated with the selected bone model638may be determined. The cortical area CA1may be determined utilizing any of the techniques disclosed herein. For example, step780F may include determining one or more perimeters at step780G. Step780G may include determining the inner perimeter638PI and/or outer perimeter638PO along the first reference plane REF1, which may correspond to the resection plane R1. Step780F may include updating the determined cortical area CA1in response to changing the selected resection angle (α) and/or changing a shape of the bone model638along the resection plane R1such as by defining one or more recesses in the resection face.

At step780H a contact area CA2is determined between the selected bone model638and the selected implant model640along a specified portion of the selected bone model638, such as along the reference plane REF1. The contact area CA2may be determined utilizing any of the techniques disclosed herein. Step780H may include determining one or more regions of overlap associated with the contact area CA2at step780I. Step780I may include determining the first region of overlap OR1corresponding to the contact area CA2and/or determining a second region of overlap OR2between the contact area CA2and a calcar region RCAL of the cortical area CAL as illustrated inFIG.12.

Step780H may include updating the contact area CA2in response to moving the selected implant model640relative to the selected bone model638, as illustrated by the implant model640′ ofFIG.13. Step780H may include updating the determined contact area CA2in response to changing the selected resection angle (α).

A percentage contact area may be determined at step780J. Referring toFIG.8, with continuing reference toFIG.14, step780J may include determining the bone area BA and determining a percentage of the contact area CA2with respect to the bone area BA.

Step780H may include determining a weighted value of the contact area CA2at step780K. The weighted value of the contact area CA2can be determined utilizing any of the techniques disclosed herein. Step780K may include determining a bone density of the selected bone model638along the contact area CA2based on the weighted value of the contact area CA2.

At step780L, at least one or more indicators relating to the contact area CA2may be displayed in the display window(s)664and/or another portion of the user interface662, such as the display window664-2relative to the image plane IP2. Step780L may include displaying any of the indicators and parameters disclosed herein, including the indicators I1-I7, PI, PV and parameters668A-668E ofFIG.12.

Step780L may include displaying a perimeter of the second region of overlap OR2along the calcar region RCAL in the display window664-2as illustrated by indicator I1, displaying a perimeter of a remainder of the contact area CA in the display window664-2that excludes the second region of overlap OR2as illustrated by indicator I2, and/or displaying a perimeter of a remainder of the cortical area CA1in the display window664-2that excludes the contact area CA2, as illustrated by indicator I3inFIG.12. The remainder of the cortical area CA1that excludes the contact area CA2may be a single contiguous region or two or more separate regions based on a placement of the selected implant model640.

Step780L may include displaying the percentage of the contact area CA2determined at step780J in the user interface662. Step780L may include displaying a first indicator in response to the percentage of the contact area CA2meeting at least one predefined contact threshold, but displaying the second indicator in response to the percentage of the contact area CA2being below the at least one predefined contact threshold. The first and second indicators may correspond to different stages of the percentage indicator PI ofFIGS.12-13, for example. Step780L may include displaying a numerical value of the percentage of the contact area CA2, as illustrated by indicator PV ofFIG.12.

Step780L may include displaying a value of the weighted contact area parameter668E in the user interface662that is determined in step780K, as illustrated inFIG.12. Step780L may include displaying an indicator in the user interface662in response to the weighted contact area exceeding at least one predefined weighted contact threshold, but displaying another indicator in the user interface662in response to the weighted contact area being below the at least one predefined weighted contact threshold. The indicator may be different states of the indicator17associated with the weighted contact area parameter668E, and may include any of the status techniques disclosed herein.

The surgeon may perform one or more steps in response to a status or value of any of the parameters disclosed herein, including the parameters668A-668E and indicators I1-I7, PI, PV, such as a value of the weighted contact area being below the predefined weighted contact threshold(s). For example, the surgeon may select another one of the implant models140stored in the database(s)136(FIG.2). The surgeon may change the selected resection angle (α) at step780E. The surgeon may interact with the user interface662to move the selected implant model640along the resection plane RE In some implementations, the selected implant model640may have a non-circular outer perimeter640PO. The surgeon may interact with the user interface662, such as a button666R in the second window664-2, to rotate the selected implant model640in a direction RD about an implant axis IA that extends through the resection plane R1, as illustrated inFIG.11.

Step780L may include displaying one or more indicators in the user interface662in response to a value of the bone density parameter668D exceeding at least one predefined density threshold, but displaying another indicator in the user interface662in response to the value of the bone density being below the at least one predefined density threshold. The indicator may be different states of the indicator16associated with the bone density parameter668D, and may include any of the status techniques disclosed herein. The value of the bone density parameter668D may be based on the weighted value of the contact area determined at step780K.

Referring toFIG.2, with continuing reference toFIG.14, the surgical plan142may be updated at step780M. Step780M may include updating a local instance of the surgical plan142and/or updating the surgical plan142in the database136. One or more iterations of the step(s) of the method780may be performed to update the surgical plan142.

The novel planning systems and methods of this disclosure can be incorporated to a practical application by providing improved positioning of implants relative to a bone surface, such as a resected face of a bone, based on conveying an enhanced representation of implant contact area relative to the cortical wall and other portions of the respective bone. The planning systems and methods may be utilized to more quickly and efficiently establish a surgical plan that reduces intra-operative time and increases precision and reproducibility of an implant position through pre-operative planning consideration of specific information relating to the relationship between the implant and an anatomy of the patient. The selected implant may be viewed substantially normal to a resection surface, which may provide the surgeon a better understanding of a shape of the osteotomy, surface area contact and amount of support and fixation for the selected implant. The planning systems may include various indicators to provide feedback to the surgeon regarding a selected implant and surgical site preparation based on surface area coverage, bone quality and bone density, for example, which can improve implant stability and healing of the patient by more closely tailoring the surgical plan to the specific patient.