US4947502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a dynamic tension bone screw
Assignee: De Puy Inc
•
Filing: 1990-03-16
•
Granted: 1990-08-14
•
Expires: 2010-03-16
Abstract
Abstract A dynamic bone fixation screw for rejoining fracture fragments of a bone to their approximate original mutual dispostion. It includes a threaded distal end member for threaded engagment with one of the bone fragments and a head member at a proximal end for engagement with another of the bone fragments. A spring member integral with and extending between the distal end member and the head member enables a predetermined torque to be initially imparted to the bone. When stress relaxation in the bone occurs, the spring member relaxes accordingly while continuing to draw the bone fragments together. The bone screw is fabricated in a unique manner.
Inventors
- 👤 John A. Engelhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:33
CPC Classifications
F; F16; F16B; F16B31/00; F16B31/04; A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; B; B23; B23P; B23P13/00; F16B35/00; F16B35/04; F16B35/041; A61B17/869
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
123 words
A method of making a dynamic fixation screw comprising the steps of: providing an elongated screw having a longitudinal axis and an axially aligned head member and a threaded shank; reducing the outer diameter of a predetermined length of the threaded shank and thereby simultaneously forming a distal end member distant from the head member as well as a reduced-diameter intermediate shank portion between said head and distal end members; and boring said head member and said reduced-diameter intermediate shank portion along the longitudinal axis of said screw to a diameter that slightly exceeds the root diameter of the threads in said reduced-diameter intermediate shank portion thereby forming a tension spring integral with and intermediate the head member and the distal end member.
Claim 2
Independent Claim
123 words
A method of making a dynamic fixation screw comprising the steps of: providing an elongated screw having a longitudinal axis and an axially aligned head member and a threaded shank; reducing the outer diameter of a predetermined length of the threaded shank and thereby simultaneously forming a distal end member distant from the head member as well as a reduced-diameter intermediate shank portion between said head and distal end members; and boring said head member and said reduced-diameter intermediate shank portion along the longitudinal axis of said screw to a diameter that slightly exceeds the root diameter of the threads in said reduced-diameter intermediate shank portion thereby forming a tension spring integral with and intermediate the head member and the distal end member.
Claim 3
Dependent Claim
33 words
A method of making a dynamic fixation screw as set forth in claim 1 including the step of forming a tool receiving recess in the distal end member coaxial with the longitudinal axis.
References Cited (Backward Citations)
US718546A
Cited
US972787A
Cited
US1204254A
Cited
US1462925A
Cited
FR560269A
Cited
US2035497A
Cited
US2037156A
Cited
DE674315C
Cited
US2563976A
Cited
US2856617A
Cited
US3051169A
Cited
US2985168A
Cited
US3076453A
Cited
US3053555A
Cited
GB1022013A
Cited
US3373647A
Cited
US3435526A
Cited
US3554193A
Cited
SU652940A1
Cited
US4227518A
Cited
DE2808969A1
Cited
SU923533A1
Cited
SU1061807A1
Cited
US4537185A
Cited
USD283591S
Cited
US4589179A
Cited
US4711232A
Cited
US4621629A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |