Orthopedic fixation devices and methods of installation thereof
Orthopedic fixation devices and methods of installing the same. The orthopedic fixation device may include a coupling element and a bone fastener, whereby the bone fastener can be loaded into the coupling element through the bottom of a bore in the coupling element and a retention member is configured to allow polyaxial rotation of the bone fastener and also to lock the bone fastener in place upon application of a force on a saddle and clamp in the coupling element.
1. An orthopedic fixation device comprising:
a coupling element comprising a body having arms extending upward from the body, the arms defining a U-shaped channel configured to receive a rod, the body having a bore extending therethrough and an indentation within the body;
a bone fastener having a head and an extension extending from the head, wherein the head is configured for loading into the coupling element through the bore;
a clamp configured to receive the head of the bone fastener;
a saddle configured to engage the clamp; and
a retention member configured to engage the clamp, the retention member having a top surface and a bottom surface, wherein the retention member is disposed in the indentation within the coupling element, and the top surface or the bottom surface of the retention is non-planar.
2. The orthopedic fixation device of claim 1 , wherein the top surface of the retention member is undulating and includes peaks and valleys.
3. The orthopedic fixation device of claim 1 , wherein the bottom surface of the retention member is non-planar.
4. The orthopedic fixation device of claim 1 , wherein the bottom surface of the retention member is undulating and includes peaks and valleys.
5. The orthopedic fixation device of claim 1 , wherein the top surface of the retention member is non-planar and the bottom surface of the retention member is planar.
6. The orthopedic fixation device of claim 1 , wherein the indentation includes an upper surface configured to contact at least a portion of the top surface of the retention member and a lower surface configured to contact at least a portion of the bottom surface of the retention member.
7. The orthopedic fixation device of claim 6 , wherein the upper surface of the indentation is planar.
8. The orthopedic fixation device of claim 1 , wherein the indentation is undulating with peaks and valleys corresponding to peaks and valleys of the retention member.
9. The orthopedic fixation device of claim 1 further comprising a locking cap assembly, wherein the locking cap assembly secures the rod to the coupling element.
10. The orthopedic fixation device of claim 1 wherein the bore of the coupling element is tapered.
11. An orthopedic fixation device comprising:
a coupling element comprising a body having arms extending upward from the body, the arms defining a U-shaped channel configured to receive a rod, the body having a bore extending therethrough and an indentation within the body;
a bone fastener having a head and an extension extending from the head, wherein the head is configured for loading into the coupling element through the bore;
a clamp configured to receive the head of the bone fastener;
a saddle configured to engage the clamp; and
a retention member configured to engage the clamp, the retention member having a top surface and a bottom surface, wherein the retention member is disposed in the indentation within the coupling element, and the top surface of the retention is non-planar.
12. The orthopedic fixation device of claim 11 , wherein the top surface of the retention member is undulating and includes peaks and valleys.
13. The orthopedic fixation device of claim 11 , wherein the bottom surface of the retention member is non-planar.
14. The orthopedic fixation device of claim 11 , wherein the bottom surface of the retention member is undulating and includes peaks and valleys.
15. The orthopedic fixation device of claim 11 , wherein the bottom surface of the retention member is planar.
16. The orthopedic fixation device of claim 11 , wherein the indentation includes an upper surface configured to contact at least a portion of the top surface of the retention member and a lower surface configured to contact at least a portion of the bottom surface of the retention member.
17. The orthopedic fixation device of claim 16 , wherein the upper surface of the indentation is planar.
18. The orthopedic fixation device of claim 11 , wherein the indentation is undulating with peaks and valleys corresponding to peaks and valleys of the retention member.
19. The orthopedic fixation device of claim 11 further comprising a locking cap assembly, wherein the locking cap assembly secures the rod to the coupling element.
20. The orthopedic fixation device of claim 11 wherein the bore of the coupling element is tapered.