US5824085A
Expired / Lapsed
US
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System and method for cavity generation for surgical planning and initial placement of a bone prosthesis
Assignee: Think Surgical Inc
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Filing: 1996-09-30
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Granted: 1998-10-20
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Expires: 2016-09-30
Abstract
Abstract Methods, systems and apparatus for planning the position of a prosthesis in a long bone in orthopaedic surgical procedures, such as hip replacement surgery, knee replacement surgery, long bone osteotomies, and the like. A bone model is generated from a scanned image of a bone, a prosthesis model is selected from a library of prosthesis models and then a cavity model is formed based on the prosthesis model and/or the bone model. The cavity model may then be positioned over the bone model, either interactively by the surgeon or automatically through an algorithm based on clinical parameters, to determine a reasonable location for implantation of a prosthesis within the bone. The cavity model allows the surgeon to optimize placement of the implant within the bone, and it provides important clinical information to the surgeon, such as areas in which press fits are provided, extension areas for possible subsidence and access areas for allowing the surgeon to insert the implant into the cavity.
Inventors
- 👤 Alind Sahay
- 👤 Brent Mittelstadt
- 👤 Willie Williamson, Jr.
- 👤 Joel Zuhars
- 👤 Peter Kazanzides
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:15
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/4097; G05B19/4099; A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/3094; A61F2/30942; A61F2/46; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/88; A61B17/8802; A61B17/8847; A61B90/00; A61B90/36; A61B90/37; A61B2090/376; A61B2090/3762; A61B34/00; A61B34/10; A61B34/30; A61F2/32; A61F2/36; A61F2/3662; A61F2/28; A61F2002/2825; A61F2002/30001; A61F2002/30316; A61F2002/30535; A61F2002/30604; A61F2002/30616; A61F2002/30667; A61F2002/3069; A61F2002/30943; A61F2002/30948; A61F2002/30952; A61F2002/4632; A61F2002/4633; G05B2219/00; G05B2219/30; G05B2219/36; G05B2219/36248; G05B2219/36251; G05B2219/45; G05B2219/45094; G05B2219/45123; G05B2219/45168; Y; Y10; Y10S; Y10S623/00; Y10S623/912; Y10S623/914
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
116 words
A method for planning the position of a prosthesis within a bone, said prosthesis having a proximal and a distal portion, said method comprising: providing a model of the prosthesis and a model of the bone; and generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone, said cavity model comprising an access region, a proximal cavity region, a distal cavity region, and a distal extension region, said distal cavity region dimensioned to provide an interference fit between said prosthesis model and said bone, and said distal extension region extending beyond the distal end of the prosthesis to provide room for subsidence of the prosthesis within the bone.
Claim 2
Independent Claim
116 words
A method for planning the position of a prosthesis within a bone, said prosthesis having a proximal and a distal portion, said method comprising: providing a model of the prosthesis and a model of the bone; and generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone, said cavity model comprising an access region, a proximal cavity region, a distal cavity region, and a distal extension region, said distal cavity region dimensioned to provide an interference fit between said prosthesis model and said bone, and said distal extension region extending beyond the distal end of the prosthesis to provide room for subsidence of the prosthesis within the bone.
Claim 3
Dependent Claim
16 words
A method as in claim 1, further comprising positioning the cavity model within the bone model.
Claim 4
Dependent Claim
31 words
A method as in claim 2, wherein the positioning step comprises automatically positioning the cavity model within the bone model based on measurements of the bone model and prothesis fit criteria.
Claim 5
Dependent Claim
26 words
A method as in claim 3 wherein the fit criteria include minimizing bone cutting, maximizing bone contact and minimizing gaps between the bone and the prosthesis.
Claim 6
Dependent Claim
29 words
A method as in claim 3 further comprising selecting a group of implants and determining a quantitative value for each implant within the group based on the fit criteria.
Claim 7
Dependent Claim
41 words
A method as in claim 3 wherein the measurements of the bone model include marking the top of a medial arc portion of the bone model and measuring inner and outer profiles of a distal canal region of the bone model.
Claim 8
Dependent Claim
28 words
A method as in claim 2, further comprising cutting the bone to form a cavity having the position and dimensions of the cavity model in the bone model.
Claim 9
Dependent Claim
36 words
A method as in claim 7 wherein the bone cutting step comprises generating a file of cutting parameters, transferring the file to automated cutting apparatus, and cutting the bone cavity based on the cutting parameter file.
Claim 10
Dependent Claim
19 words
A method as in claim 1, wherein the bone model is generated from a scanned image of the bone.
Claim 11
Dependent Claim
24 words
A method as in claim 1, wherein the prosthesis model is selected from a library of prosthesis models corresponding to different types of prostheses.
Claim 12
Dependent Claim
34 words
A method as in claim 1, where the first cavity model is generated by a set of rules which generate cavity dimensions based on the prosthesis model in the absence of the bone model.
Claim 13
Dependent Claim
44 words
A method as in claim 10 or 11, wherein the first cavity model comprises an actual cavity and an access region, the method further comprising generating an access region model based on the model of the prosthesis to provide access to the actual cavity.
Claim 14
Dependent Claim
43 words
A method as in claim 12, wherein the access region model generating step includes determining a cross-sectional area of a proximal portion of the model of the prosthesis and trimming said cross-sectional area based on a recession angle and a lateral trimming distance.
Claim 15
Dependent Claim
55 words
The method of claim 13 further comprising generating a distal cavity extension model by determining the cross-sectional area of the distal cavity region and extending the distal cavity region by a distance based on fit criteria, said fit criteria including cortical bone thickness and contact between the cortical bone and the model of the prosthesis.
Claim 16
Dependent Claim
50 words
A method as in claim 12, wherein the actual cavity comprises a proximal cavity region, a distal cavity region and a distal cavity extension, the method further comprising providing a model of a broach and generating a proximal cavity region model based on the prosthesis model and the broach model.
Claim 17
Dependent Claim
25 words
The method of claim 15 wherein the proximal cavity region model is generated by applying an interference pattern function to the prosthesis and broach models.
Claim 18
Dependent Claim
32 words
A method as in claim 1, wherein the first cavity model is generated by a set of rules which generate cavity dimensions based on both implant model information and bone model information.
Claim 19
Dependent Claim
31 words
A method as in claim 1, wherein the bone is a long bone taken from a group consisting essentially of the femur, the tibia, the humerus, the ulna and the radius.
Claim 20
Dependent Claim
46 words
A method as in claim 1, wherein the positioning step comprises: observing images of the bone model and the cavity model on a display; and adjusting the image of the bone model relative to the image of the cavity model as they appear on the display.
Claim 21
Dependent Claim
27 words
A method as in claim 19, wherein the images include at least one of the group consisting of 3D images, axial cross-sectional images, and transverse cross-sectional images.
Claim 22
Dependent Claim
57 words
A method as in claim 1 further comprising adjusting the dimensions of the first cavity model to produce a second cavity model and repositioning the second cavity model by observing images of the bone model and the second cavity model on the display and adjusting the relative positions of the images as they appear on the display.
Claim 23
Independent Claim
119 words
A method for planning the position of a prosthesis within a bone, said method comprising: providing a model of the prosthesis and a model of the bone; generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone; wherein the first cavity model comprises an actual cavity and an access region, the method further comprising generating an access region model based on the model of the prosthesis to provide access to the actual cavity; and wherein the access region model generating step includes determining a cross-sectional area of a proximal portion of the model of the prosthesis and trimming said cross-sectional area based on a recession angle and a lateral trimming distance.
Claim 24
Independent Claim
119 words
A method for planning the position of a prosthesis within a bone, said method comprising: providing a model of the prosthesis and a model of the bone; generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone; wherein the first cavity model comprises an actual cavity and an access region, the method further comprising generating an access region model based on the model of the prosthesis to provide access to the actual cavity; and wherein the access region model generating step includes determining a cross-sectional area of a proximal portion of the model of the prosthesis and trimming said cross-sectional area based on a recession angle and a lateral trimming distance.
Claim 25
Independent Claim
106 words
A method for planning the position of a prosthesis within a bone, said method comprising: providing a model of the prosthesis and a model of the bone; generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone; wherein the positioning step comprises automatically positioning the cavity model within the bone model based on measurements of the bone model and prothesis fit criteria; and wherein the measurements of the bone model include marking the top of a medial arc portion of the bone model and measuring inner and outer profiles of a distal canal region of the bone model.
Claim 26
Independent Claim
106 words
A method for planning the position of a prosthesis within a bone, said method comprising: providing a model of the prosthesis and a model of the bone; generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone; wherein the positioning step comprises automatically positioning the cavity model within the bone model based on measurements of the bone model and prothesis fit criteria; and wherein the measurements of the bone model include marking the top of a medial arc portion of the bone model and measuring inner and outer profiles of a distal canal region of the bone model.
Claim 27
Independent Claim
95 words
A method for planning the position of a prosthesis within a bone, said method comprising: providing a model of the prosthesis and a model of the bone; generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone; and adjusting the dimensions of the first cavity model to produce a second cavity model and repositioning the second cavity model by observing images of the bone model and the second cavity model on the display and adjusting the relative positions of the images as they appear on the display.
Claim 28
Independent Claim
95 words
A method for planning the position of a prosthesis within a bone, said method comprising: providing a model of the prosthesis and a model of the bone; generating based on the prosthesis model a first cavity model intended to accommodate the prosthesis within the bone; and adjusting the dimensions of the first cavity model to produce a second cavity model and repositioning the second cavity model by observing images of the bone model and the second cavity model on the display and adjusting the relative positions of the images as they appear on the display.
Claim 29
Independent Claim
28 words
A method as in any of claims 22 to 24, wherein the prosthesis model is selected from a library of prosthesis models corresponding to different types of prostheses.
Claim 30
Independent Claim
38 words
A method as in any of claims 22 to 24, where the first cavity model is generated by a set of rules which generate cavity dimensions based on the prosthesis model in the absence of the bone model.
Claim 31
Independent Claim
87 words
A method for planning the position of a prosthesis within a bone, said prosthesis having a proximal and a distal portion, said method comprising: providing a model of the bone; providing a first cavity model intended to accommodate the prosthesis within the bone, said cavity model comprising an access region, a distal cavity region dimensioned to provide an interference fit between a prosthesis model and the bone, and a distal extension region extending beyond the distal cavity region; and positioning the cavity model in the bone model.
Claim 32
Independent Claim
87 words
A method for planning the position of a prosthesis within a bone, said prosthesis having a proximal and a distal portion, said method comprising: providing a model of the bone; providing a first cavity model intended to accommodate the prosthesis within the bone, said cavity model comprising an access region, a distal cavity region dimensioned to provide an interference fit between a prosthesis model and the bone, and a distal extension region extending beyond the distal cavity region; and positioning the cavity model in the bone model.
Claim 33
Dependent Claim
16 words
A method as in claim 27, further comprising positioning the cavity model within the bone model.
Claim 34
Dependent Claim
19 words
A method as in claim 27, wherein the bone model is generated from a scanned image of the bone.
Claim 35
Dependent Claim
31 words
A method as in claim 27, wherein the bone is a long bone taken from a group consisting essentially of the femur, the tibia, the humerus, the ulna and the radius.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-19 | 2002-04-20 | 2002-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-19 | 2006-04-20 | 2006-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-19 | 2010-04-20 | 2010-10-20 | $7700.00 | Window Closed / Lapsed |