Robotic guided femoral head reshaping

A method of performing hip surgery with a robotic guided system on a patient with femoral acetabular impingement can include identifying the femoral acetabular impingement on the patient. Data related to a proximal femur and an acetabulum of the patient is acquired. A three-dimensional model of at least one of the patient's proximal femur and acetabulum is created based on the data acquired. A location and amount of bone to be removed is determined. Dynamic movement limits of a cutting tool associated with the robotic guided system is set based on the determination. The determined bone of at least one of the proximal femur and acetabulum is removed with the tool while being inhibited from moving the tool outside of the dynamic limit by the robotic guided system.

FIELD

The present disclosure relates to a method of performing hip surgery, and more specifically to a method of performing hip surgery with a robotic guided system on a patient with femoral acetabular impingement.

BACKGROUND

Femoral acetabular impingement can occur when a portion of a proximal femur rubs unfavorably against an acetabulum. One form of femoral acetabular impingement is called “cam impingement” where a portion of bone protrudes on a proximal femur generally at a location on the femur where the femoral head and neck meet. The protrusion, in some instances, can rub excessively against the acetabulum. Another kind of femoral acetabular impingement called “pincer impingement” can occur where a portion of bone protrudes on an anterior rim of the acetabulum. The protrusion on the acetabulum can block normal movement of the proximal femur. It is also possible to have a combination of both cam and pincer impingement on a given patient's hip. Femoral acetabular impingement can cause intermittent groin or hip pain that can intensify over time.

In some instances, it may be desirable to cut away or burr the protruding bone on the proximal femur and/or acetabulum. In one method, a surgeon can cut away the identified protruding bone with a tool, such as a burr that is negotiated freehand by a surgeon. In some instances, relying on a surgeon's freehand movement of such a cutting tool can result in removing too much or not enough bone. In this regard, removing too much bone from the proximal femur can compromise the integrity of the proximal femur and may lead to a greater risk of femoral neck fracture. Moreover, in some examples, a surgeon does not remove enough bone, which can lead to future impingement problems.

SUMMARY

A method of performing hip surgery with a robotic guided system on a patient with femoral acetabular impingement can include identifying the femoral acetabular impingement on the patient. Data related to a proximal femur and an acetabulum of the patient is acquired. A three-dimensional model of at least one of the patient's proximal femur and acetabulum is created based on the data acquired. A location and amount of bone to be removed can be determined. Dynamic movement limits of a cutting tool associated with the robotic guided system is set based on the determination. The determined bone of at least one of the proximal femur and acetabulum is removed with the tool while being inhibited from moving the tool outside of the dynamic limit by the robotic guided system.

According to additional features, identifying the femoral acetabular impingement can include identifying at least one of a protrusion on the proximal femur and a protrusion on the acetabulum. The protrusion on the proximal femur can comprise a protrusion at an intersection of a femoral head and a femoral neck of the proximal femur. The protrusion on the acetabulum can comprise a protrusion on an anterior rim of the acetabulum. Acquiring the data can include touching at least one of the proximal femur and the acetabulum of the patient at a plurality of locations with a pointing tool associated with the robotic guided system. Touching at least one of the proximal femur and the acetabulum can comprise touching at least one of the proximal femur and the acetabulum with a stylus associated with the robotic guided system.

According to additional features, the pointing tool can be coupled to a robotic arm of the robotic guided system. At least one of the proximal femur and the acetabulum of the patient can be subsequently touched with the pointing tool. The pointing tool can be subsequently removed from the robotic arm. The cutting tool can be subsequently coupled to the robotic arm. The identified bone can be subsequently removed with the cutting tool. Identifying the femoral acetabular impingement can comprise acquiring medical imaging of the proximal femur and the acetabulum of the patient. According to other features, acquiring medical imaging can comprise performing at least one of an x-ray and a magnetic resonance imaging. Removing the determined bone with the cutting tool can comprise removing the determined bone with a burr disposed on the cutting tool.

DETAILED DESCRIPTION

With initial reference toFIG. 1, a robotic guided femoral head/acetabulum reshaping system according to one example of the present teachings is shown and generally identified at reference numeral10. The robotic guided femoral head/acetabulum reshaping system10can generally comprise a surgical tool guiding device12and a computing system or work station14. The surgical tool guiding device12can generally comprise a robotic arm18that can provide selective dynamic movement relative to a base20. The robotic arm18can generally include a first arm portion22and a second arm portion24. The computing system14can generally comprise a computer or processor30having a display32and an input device34. The computing system14can communicate with the surgical tool guiding device12, as will become appreciated from the following discussion. As will be described in greater detail herein, a surgeon38can use the surgical tool guiding device12of the robotic guided femoral head/acetabulum reshaping system10to limit or control a dynamic range of movement permitted by a surgical tool40that is coupled to the robotic arm18. In this regard, the surgical tool guiding device12can inhibit movement of the surgical tool40in such a way as to confine any cutting or burring of a femoral head42and/or an acetabulum44within a pre-determined boundary.

The surgical tool guiding device12will now be described in greater detail. The first arm portion22can be generally movably coupled to the base20through a first joint50. The second arm24can be generally movably coupled to the first arm portion22through a second joint52. The base20can generally include a plurality of wheels56that can be selectively locked to immobilize the base20relative to a floor60. In other examples, the base20can be configured to directly sit on the floor60or alternatively include legs or other members that can support the base20relative to the floor60. A distal end of the second arm portion24can include a coupling62. The coupling62can be manipulated for selectively coupling to various instruments or surgical tools40. The instruments or tools can include, but are not limited to, a stylus40a, and a cutting tool40b, such as a burring instrument.

In various examples, the first joint50can provide translation and/or rotation of the first arm portion22relative to the base20. The second joint52can provide translation and/or rotation of the second arm24relative to the first arm portion22. A hydraulic system58can be disposed throughout the surgical tool guiding device12. For example, the hydraulic system58can cooperate with the first arm portion22and/or the second arm portion24to confine movement of the robotic arm18within an allowed pre-defined range of motion as will be described in detail herein. For example, the hydraulic system58route hydraulic fluid to areas that can freeze or lock selected components of the surgical tool guiding device12to preclude unwanted advancement of the surgical tool40beyond the identified allowed or pre-determined range of motion. Other mechanisms can be incorporated on the robotic arm18to assist in controlling or limiting movement of the robotic arm18. Furthermore, it can be appreciated that while the robotic arm18has been described as having two arm portions that move relative to each other and a base, other configurations may be provided.

With additional reference now toFIG. 2, an exemplary hip joint70having femoral acetabular impingement is shown. The hip joint70generally includes a proximal femur72having the femoral head42and a femoral neck76. The hip joint70further comprises the acetabulum44that receives the femoral head42. The exemplary hip joint70has a femoral acetabular impingement condition caused collectively by a cam impingement82and a pincer impingement84. The cam impingement82can be generally caused by a femoral protrusion86formed at an area where the femoral head42and the femoral neck76meet. The pincer impingement84can be generally caused by an acetabular protrusion88formed on an anterior rim90of the acetabulum44. It will be appreciated that while the exemplary hip joint70is shown having both of a cam impingement82and a pincer impingement84that the hip joint70may alternatively comprise only one of the cam impingement82and pincer impingement84that cause femoral acetabular impingement.

With further reference now toFIG. 3, an exemplary method of performing hip surgery with the robotic guided system10on a patient92with femoral acetabular impingement is shown and generally identified at reference numeral100. In block102, the surgeon38can identify the femoral acetabular impingement. According to various examples, the surgeon38can identify the femoral acetabular impingement by medical imaging, such as, but not limited to, an x-ray, a computerized axial tomography scan or a magnetic resonance imaging procedure. The medical imaging procedure can produce an image, such as illustrated inFIG. 2where a surgeon can identify the femoral protrusion86and/or the acetabular protrusion88as part of an initial broad identification step.

In block104, the surgeon38can acquire data related to the femoral head42, femoral neck76and/or the acetabulum44. According to one example of the present teachings, the surgeon38can utilize the stylus40awith the surgical tool40. The stylus40acan be attached to the tool40of the robotic arm18. The surgeon38can move the stylus40aand touch a distal tip of the stylus40ato a plurality of locations on the femoral head42, femoral neck76and/or the acetabulum44. Each time the distal tip of the stylus40atouches the femoral head42, femoral neck76and/or the acetabulum44, a reference point in space can be communicated from the surgical tool guiding device12to the computing system14based on sensors in the linkages50and52. In some examples, the data acquired with the stylus40acan be used to verify the image data obtained during the medical imaging procedure.

In block106, software of the computing system14can be used to create a three-dimensional model of the patient's hip joint70based on the plurality of data points corresponding to contacting the surface of the femoral head42, femoral neck76and acetabulum44from the stylus40. In other features, the three-dimensional model of the patient's hip joint can be created from the medical imaging procedure.

In block108, the surgeon38can use the computing system14to reference the three-dimensional model to determine and verify the location and amount of bone (e.g., femoral protrusion86and/or acetabular protrusion88) to be removed relative to the 3-D model. In some examples, a surgeon can reference an image on the display32and use the input device34to draw or mark on the image the areas of bone to be removed. Once the location and amount of bone that is to be removed has been determined, software in the computing system14can be used to set dynamic movement limits of the tool40based on the marked image. In other examples, the dynamic movement limits can be automatically set based on a pre-operative determination of the bone to be removed.

In this regard, movement of the surgical tool40can be restricted to areas in space that correspond with locations in space having the femoral protrusion86and/or the acetabular protrusion88. The surgical tool40can therefore be inhibited from moving into areas in space that correspond to healthy bone and/or tissue, etc. In this regard, the computing system14can communicate with the hydraulic system58of the surgical tool guiding device12to set limits on the dynamic movement of some or all of the components in the robotic arm18, such that the robotic arm18(or portions thereof) freezes, restricts or prevents movement of the surgical tool40when the surgeon38attempts (purposely or inadvertently) to move the surgical tool40outside of the established boundary. In one example, the surgeon38can remove the stylus40afrom the coupling62and replace it with the cutting tool40b, such as a burring instrument. In block112, a surgeon38can use the cutting tool40bto cut away or burr the femoral protrusion86and/or the acetabular protrusion88while being inhibited from moving the cutting tool40boutside of the dynamic limit established by the computing system14.

As can be appreciated, the robotic guided femoral head/acetabulum reshaping system10can be particularly useful to a surgeon38by precluding the surgeon38from inadvertently moving the cutting tool40btoo far into bone of the proximal femur72and/or the acetabulum44. Therefore, the robotic guided femoral head/acetabulum reshaping system10can assist a surgeon38in guiding the cutting tool40bthree-dimensionally, such that it is confined to cut bone only in identified areas of a femoral protrusion86and/or an acetabular protrusion88to obtain a natural shaped femoral acetabular substantially spherical joint.

Turning now toFIG. 4, the step of acquiring data related to the femoral head42, femoral neck76and/or acetabulum44identified in block104will be further described. In block120, a surgeon38can gain access to a patient's femur/acetabulum. A surgeon38can use any known technique or procedure, such as providing a single or a collection of entry points through a patient's skin to suitably access the proximal femur72and the acetabulum44. In block122, the surgeon38can use the stylus40ato touch the surface of the proximal femur72and/or the acetabulum44. In block124, the plurality of locations in space corresponding to the surfaces touched by the stylus40aare uploaded into software in the computing system14. The software can convert the plurality of locations in space into a three-dimensional model of the patient's hip joint70.