Flexible plate fixation of bone fractures
Embodiments provide methods, apparatuses, and systems for fixation of a fractured bone with a bone plate. In various embodiments, the systems and plates provide elastic suspension of the receiving holes relative to an osteosynthesis plate. This elastic suspension can promote load distribution between the screws that connect a bone segment to the plate, thereby reducing stress risers and load shielding effect. In addition, stress at the screw holes, and within the construct as a whole, is reduced by incorporation of these elastic elements in the plate. Additionally, in some embodiments where fracture healing by callus formation is desired, elastic suspension of the receiving holes relative to the osteosynthesis plate can enable small, controlled amounts of relative motion between bone fragments connected by the plate. This relative motion can promote fracture healing by callus formation.
1. A device, comprising:
a bone fracture fixation plate having an upper surface and a bone-facing surface, the bone plate comprising one or more slots extending through the plate from the upper surface to the bone-facing surface, the one or more slots circumscribing a periphery of one or more receiving holes to enable relative displacement between the receiving holes within the bone plate, wherein the one or more slots are at least partially filled with an elastomer to support elastic suspension of said receiving holes in the bone plate, wherein the elastomer is disposed within the slots such that the elastomer circumscribes the periphery of the one or more receiving holes.
2. The device of claim 1 , wherein said receiving holes are suspended to permit translation relative to the plate along the longitudinal axis of the plate while substantially limiting motion of the one or more receiving holes in a direction that is perpendicular to the upper or the bone-facing surface of the bone plate.
3. The device of claim 1 , wherein the elastomer may positively adhere at least to a portion of the slot surface to affect a desired elastic constraint of the receiving hole relative to the device.
4. The device of claim 1 , wherein the elastomer may extend beyond a lumen of the slot to provide additional means for support of a receiving hole at the upper or bone-facing surfaces of the plate.
5. The device of claim 1 , wherein the elastomer has a Modulus of elasticity in the range of 0.1-50 MPa.
6. The device of claim 1 , wherein the elastomer comprises an elastomer lumen, and wherein at least one the receiving holes is removable as a solitary element or in conjunction with the elastomer lumen.
7. The device of claim 1 , wherein one or more receiving holes may have features for positive locking with a screw head to enable angle-stable fixation of a plate to the bone in absence of compression of said plate onto the bone surface, which, in conjunction with the elastic suspension of receiving holes, enables controlled relative motion between the plate and the bone surface.
8. The device of claim 1 , wherein one or more receiving hole elements extend past the bone-facing surface of the plate to elevate the plate body over the bone surface when the receiving hole is being compressed onto the bone surface with a non-locking bone screw, which, in conjunction with the elastic suspension of receiving holes, enables controlled relative motion between the plate and the bone surface.
9. The device of claim 1 ,wherein the periphery of the one or more receiving holes comprises a rivet, wherein the rivet is adapted to protect the elastomer from excessive deformation in a direction perpendicular to an upper or a lower plane of the bone fracture fixation plate.
10. The device of claim 9 , wherein the rivet comprises a threaded receiving hole.
11. The device of claim 9 , wherein the rivet is adapted to translate along a longitudinal axis of the bone fracture fixation plate.
12. The device of claim 1 , wherein the receiving holes are arranged in a staggered pattern to improve torsional stability of the fixation construct.
13. The device of claim 1 , wherein the one or more slots comprise two or more angled, anti-parallel portions adapted to protect the elastomer from excessive deformation in a direction perpendicular to an upper or a lower plane of the bone fracture fixation plate.
14. The device of claim 1 , wherein the elastomer material comprises silicone.
15. The device of claim 1 , further comprising a threaded insert, wherein the space between the threaded insert and the bone plate is at least partially filled with the elastomer material.
16. The device of claim 1 , wherein at least one of the one or more receiving holes is threaded for engaging a fixation element inserted therethrough.
17. The device of claim 1 , wherein the one or more slots are filled with the elastomer.
18. A device, comprising:
a bone fracture fixation plate comprising one or more receiving holes configured to receive a rivet;
a rivet disposed non-rigidly within one of the one or more receiving holes, wherein a slot is present between the rivet and the plate,
wherein the slot is at least partially filled with an elastomer to provide elastic suspension of the rivet within the receiving hole in the bone plate to enable relative displacement between the rivet and the bone plate.
19. The device of claim 18 , wherein the slot circumscribes the rivet.
20. The device of claim 19 , wherein the slot is filled with the elastomer.