Femoral implant for hip arthroplasty
View Patent ↗Novel femoral implants for use in hip arthroplasty are described and illustrated. The femoral implant comprise a stem and neck portion, with the neck portion having a novel configuration that provides for improved range in motion for the prosthesis without compromising strength of the implant.
1. A prosthetic femoral implant suitable for use in hip arthroplasty, said implant comprising:
a. a longitudinal stem having a distal end and a proximal end, said stem further having a longitudinal axis extending from said proximal end to said distal end;
b. a neck portion extending from said proximal end of said stem and having a femoral head configure for engagement within an acetabulum;
c. said neck portion having an axis extending through said femoral head and neck portion to intersect said stem axis, and wherein a transverse cross section of said neck portion taken perpendicular to said neck axis further comprises (i) a medial/lateral axis bisecting said cross section through a medial-most point along said medial edge and a point along said lateral edge of said cross section, thereby creating two anterior and posterior halves about said medial/lateral axis, said medial/lateral axis further defining a maximum medial/lateral width of said cross-section; and (ii) a maximum anterior/posterior axis intersecting said anterior and posterior edges and said medial/lateral axis to define a maximum anterior/posterior width of said cross section;
d. said transverse cross section further having a configuration defined by a medially-positioned circle comprising (i) said medial-most point of said cross section, (ii) a point taken on said anterior edge of said cross section, and (iii) a point taken on said posterior edge of said cross section, wherein each of said anterior and posterior edge points are located along said anterior and posterior edges, respectively, at a distance of 10% of said maximum medial/lateral width measured laterally from said medial-most edge point; and
e. said medially-positioned circle having a medial diameter ranging in length of about 66% or less of said maximum anterior/posterior width of said cross section.
2. The implant of claim 1 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
3. The implant of claim 1 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
4. The implant of claim 3 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
5. The implant of claim 3 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
6. The implant of claim 5 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
7. The implant of claim 2 , wherein said transverse cross section is taken at one or more points located at or between about 12 mm to about 18 mm below a center of said femoral head along said neck axis.
8. The implant of claim 7 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
9. The implant of claim 8 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
10. A prosthetic femoral implant suitable for use in hip arthroplasty, said implant comprising:
a. a longitudinal stem having a distal end and a proximal end, said stem further having a longitudinal axis extending from said proximal end to said distal end;
b. a neck portion extending from said proximal end of said stem and having a femoral head configured for engagement within an acetabulum;
c. said neck portion having an axis extending through said femoral head and neck portion to intersect said stem axis, and wherein a transverse cross section of said neck portion taken perpendicular to said neck axis further comprises (i) a medial/lateral axis bisecting said cross section through a medial-most point along said medial edge and a point along said lateral edge of said cross section, thereby creating two anterior and posterior halves about said medial/lateral axis, said medial/lateral axis further defining a maximum medial/lateral width of about 9 mm or greater; and (ii) a maximum anterior/posterior axis intersecting said anterior and posterior edges and said medial/lateral axis to define a maximum anterior/posterior width of said cross-section;
d. said transverse cross section further having a configuration defined by a medially-positioned circle comprising (i) said medial-most point of said cross section, (ii) a point taken on said anterior edge of said cross section, and (iii) a point taken on said posterior edge of said cross section, wherein each of said anterior and posterior edge points are located along said anterior and posterior edges, respectively, at a distance of 10% of said medial/lateral width measured laterally from said medial-most edge point; and
e. said medially-positioned circle having a medial diameter ranging in length of about 66% or less of said maximum anterior/posterior width of said cross section.
11. The implant of claim 10 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
12. The implant of claim 10 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
13. The implant of claim 12 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
14. The implant of claim 12 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
15. The implant of claim 14 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
16. The implant of claim 10 , wherein said maximum medial/lateral width is about 10 mm or greater.
17. The implant of claim 16 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
18. The implant of claim 17 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
19. The implant of claim 18 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
20. The implant of claim 18 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
21. A prosthetic femoral implant suitable for use in hip arthroplasty, said implant comprising:
a. a longitudinal stem having a distal end and a proximal end, said stem further having a longitudinal axis extending from said proximal end to said distal end;
b. a neck portion extending from said proximal end of said stem and having a femoral head configured for engagement within an acetabulum;
c. said neck portion having an axis extending through said femoral head and neck portion to intersect said stem axis, and wherein a transverse cross section of said neck portion taken perpendicular to said neck axis further comprises (i) a medial/lateral axis bisecting said cross section through a medial-most point along said medial edge and a point along said lateral edge of said cross section, thereby creating two substantially symmetrical anterior and posterior halves about said medial/lateral axis, said medial/lateral axis further defining a maximum medial/lateral width of said cross-section; and (ii) a maximum anterior/posterior axis intersecting said anterior and posterior edges and said medial/lateral axis to define a maximum anterior/posterior width of said cross section;
d. said transverse cross section further having a configuration defined by a medially-positioned circle comprising (i) said medial-most point of said cross section, (ii) a point taken on said anterior edge of said cross section, and (iii) a point taken on said posterior edge of said cross section, wherein each of said anterior and posterior edge points are located along said anterior and posterior edges, respectively, at a distance of 10% of said maximum medial/lateral width measured laterally from said medial-most edge point; and
e. said medially-positioned circle having a medial diameter ranging in length of about 66% or less of said maximum anterior/posterior width of said cross section.
22. The implant of claim 21 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
23. The implant of claim 21 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
24. The implant of claim 23 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
25. The implant of claim 23 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
26. The implant of claim 25 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
27. The implant of claim 22 , wherein said transverse cross section is taken at one or more points located at or between about 12 mm to about 18 mm below a center of said femoral head along said neck axis.
28. The implant of claim 27 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
29. The implant of claim 28 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
30. The implant of claim 21 , wherein said maximum medial/lateral width is about 9 mm or greater.
31. The implant of claim 30 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
32. The implant of claim 30 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
33. The implant of claim 32 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
34. The implant of claim 33 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
35. The implant of claim 21 , wherein said maximum medial/lateral width is about 10 mm or greater.
36. The implant of claim 35 , wherein said transverse cross section is taken at one or more point located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
37. The implant of claim 35 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
38. The implant of claim 37 , wherein said transverse cross section is taken at one or more points located at or between about 10 mm to about 22 mm below a center of said femoral head along said neck axis.
39. The implant of claim 38 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.
40. The implant of claim 31 , wherein said transverse cross section is taken at one or more points located at or between about 12 mm to about 18 mm below a center of said femoral head along said neck axis.
41. The implant of claim 40 , wherein said medial diameter is about 55% or less of said maximum anterior/posterior width of said cross section.
42. The implant of claim 41 , wherein said medial diameter is from about 40% to about 50% of said maximum anterior/posterior width of said cross section.