US4997447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw-threaded acetabular component of hip joint prosthesis
Assignee: Smith and Nephew Inc
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Filing: 1989-08-16
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Granted: 1991-03-05
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Expires: 2009-08-16
Abstract
Abstract An acetabular implant of a hip joint prosthesis comprising a metal cup shell (2) having an external self-tapping thread extending around the circumference of the shell. The thread is divided into a plurality of segments (8, 10) by a plurality of tapping grooves (16). The thread radius (Ra, Rb, Rc, Rd) of the thread segments (8, 10) progressively decreases from the leading end (12) to the trailing end (14) of a segment (8 or 10). The tapping grooves (16) are preferably arranged in pairs dividing the thread into alternating long (8) and short (10) segments. The construction of the thread reduces the propensity of the implant to jam during insertion.
Inventors
- 👤 Philip Shelley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:29
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/34; A61F2002/30001; A61F2002/30316; A61F2002/30317; A61F2002/30322; A61F2/30767; A61F2/30771; A61F2002/3082; A61F2002/30825; A61F2002/30827; A61F2002/3085; A61F2002/30858; A61F2250/00; A61F2250/0014; A61F2250/0026
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
68 words
An acetabular implant of a hip joint prothesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii continuously-progressively decreasing from the leading end toward the trailing end of each segment.
Claim 2
Dependent Claim
68 words
An acetabular implant of a hip joint prothesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii continuously-progressively decreasing from the leading end toward the trailing end of each segment.
Claim 3
Dependent Claim
37 words
An acetabular implant according to claim 1 wherein the thread depth of each thread segment decreases from the leading to the trailing end of the segment by at least 3 percent and not more than 30 percent.
Claim 4
Dependent Claim
30 words
An acetabular implant according to claim 2 wherein the thread depth of each thread segment decreases from the leading to the trailing end of the segment by approximately 10 percent.
Claim 5
Dependent Claim
27 words
An acetabular implant according to claim 2 wherein each thread segment has a width progressively decreasing from the leading end toward the trailing end of the segment.
Claim 6
Dependent Claim
116 words
An acetabular implant of a hip joint prosthesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii progressively decreasing from the leading end toward the trailing end of each segment, each thread segment having a thread depth decreasing from the leading to the trailing end of the segment by at least 3 percent and not more than 30 percent, and the tapping grooves being arranged in pairs dividing the thread segments into alternating long and short thread segments.
Claim 7
Dependent Claim
116 words
An acetabular implant of a hip joint prosthesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii progressively decreasing from the leading end toward the trailing end of each segment, each thread segment having a thread depth decreasing from the leading to the trailing end of the segment by at least 3 percent and not more than 30 percent, and the tapping grooves being arranged in pairs dividing the thread segments into alternating long and short thread segments.
Claim 8
Dependent Claim
29 words
An acetabular implant according to claim 5 wherein the thread tapping grooves have a total volume at least equal to the total volume of all of the thread segments.
Claim 9
Dependent Claim
21 words
An acetabular implant according to claim 6 wherein the long thread segments are 50-1800 percent longer than the short thread segments.
Claim 10
Dependent Claim
22 words
An acetabular implant according to claim 7 wherein the long thread segments are approximately 500 percent longer than the short thread segments.
Claim 11
Dependent Claim
87 words
An acetabular implant of a hip joint prosthesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii progressively decreasing from the leading end toward the trailing end of each segment, and the tapping grooves being arranged in pairs dividing the thread segments into alternating long and short thread segments.
Claim 12
Dependent Claim
87 words
An acetabular implant of a hip joint prosthesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii progressively decreasing from the leading end toward the trailing end of each segment, and the tapping grooves being arranged in pairs dividing the thread segments into alternating long and short thread segments.
Claim 13
Dependent Claim
27 words
An acetabular implant according to claim 9 wherein each thread segment has a width progressively decreasing from the leading end toward the trailing end of the segment.
Claim 14
Dependent Claim
29 words
An acetabular implant according to claim 9 wherein the thread tapping grooves have a total volume at least equal to the total volume of all of the thread segments.
Claim 15
Dependent Claim
106 words
An acetabular implant of a hip joint prosthesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii progressively decreasing from the leading end toward the trailing end of each segment, each thread segment having a width progressively decreasing from the leading end toward the trailing end of the segment, and the tapping grooves being arranged in pairs dividing the thread segments into alternating long and short thread segments.
Claim 16
Dependent Claim
106 words
An acetabular implant of a hip joint prosthesis comprising a generally hemispherical or frustoconical metal cup shell having an external self-tapping thread extending around the circumference of the shell, the thread being divided by a plurality of tapping grooves into a plurality of thread segments having leading and trailing ends, the thread segments having radii progressively decreasing from the leading end toward the trailing end of each segment, each thread segment having a width progressively decreasing from the leading end toward the trailing end of the segment, and the tapping grooves being arranged in pairs dividing the thread segments into alternating long and short thread segments.
Claim 17
Dependent Claim
21 words
An acetabular implant according to claim 12 wherein the long thread segments are 50-1800 percent longer than the short thread segments.
Claim 18
Dependent Claim
22 words
An acetabular implant according to claim 13 wherein the long thread segment are approximately 500 percent longer than the short thread segments.
Claim 19
Dependent Claim
21 words
An acetabular implant according to claim 14 wherein the long thread segments are 50-1800 percent longer than the short thread segments.
Claim 20
Dependent Claim
22 words
An acetabular implant according to claim 15 wherein the long thread segments are approximately 500 percent longer than the short thread segments.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-04 | 1994-09-03 | 1995-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-04 | 1998-09-03 | 1999-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-04 | 2002-09-03 | 2003-03-05 | $7700.00 | Window Closed / Lapsed |