US 12,251,138 B2
Pivotal bone anchor assembly with biasing members for pre-lock friction fit
Roger P. Jackson, Prairie Village, KS (US); and James L. Surber, Kansas City, KS (US)
Filed by Roger P. Jackson, Prairie Village, KS (US)
Filed on Oct. 18, 2023, as Appl. No. 18/489,811.
Application 18/489,811 is a continuation of application No. 17/571,208, filed on Jan. 7, 2022, granted, now 11,793,553.
Application 17/571,208 is a continuation of application No. 16/259,905, filed on Jan. 28, 2019, granted, now 11,219,471, issued on Jan. 11, 2022.
Application 16/259,905 is a continuation of application No. 15/521,163, granted, now 10,188,432, issued on Jan. 29, 2019, previously published as PCT/US2015/056706, filed on Oct. 21, 2015.
Claims priority of provisional application 62/212,253, filed on Aug. 31, 2015.
Claims priority of provisional application 62/200,501, filed on Aug. 3, 2015.
Claims priority of provisional application 62/200,491, filed on Aug. 3, 2015.
Claims priority of provisional application 62/194,955, filed on Jul. 21, 2015.
Claims priority of provisional application 62/137,713, filed on Mar. 24, 2015.
Claims priority of provisional application 62/137,707, filed on Mar. 24, 2015.
Claims priority of provisional application 62/078,173, filed on Nov. 11, 2014.
Claims priority of provisional application 62/078,154, filed on Nov. 11, 2014.
Claims priority of provisional application 62/066,813, filed on Oct. 21, 2014.
Claims priority of provisional application 62/066,806, filed on Oct. 21, 2014.
Prior Publication US 2024/0041500 A1, Feb. 8, 2024
Int. Cl. A61B 17/70 (2006.01); A61B 17/86 (2006.01); A61B 90/00 (2016.01)
CPC A61B 17/7037 (2013.01) [A61B 17/702 (2013.01); A61B 17/7035 (2013.01); A61B 17/7038 (2013.01); A61B 17/8605 (2013.01); A61B 17/863 (2013.01); A61B 17/864 (2013.01); A61B 2090/037 (2016.02)] 20 Claims
OG exemplary drawing
 
1. A pivotal bone anchor assembly for securing an elongate rod to a bone of a patient, the pivotal bone anchor assembly comprising:
a bone anchor including a capture portion and an anchor portion opposite the capture portion configured for fixation to the bone; and
a receiver assembly in a pre-assembled configuration prior to an uploading of the capture portion of the bone anchor into the receiver assembly through a lower opening, the receiver assembly including:
a receiver including a base defining an axial bore centered around a longitudinal axis of the receiver and communicating with a bottom surface of the base through the lower opening, and a pair of integral arms extending upwardly from the base to define a channel configured to receive the elongate rod, the axial bore extending upward through the channel to tops of the integral arms and including a discontinuous guide and advancement structure proximate the tops of the integral arms, a recess above the lower opening, and a spherical seating surface adjacent to the lower opening;
a retainer disposed in the axial bore prior to the uploading of the capture portion of the bone anchor and expandable within the recess, the retainer including an inner surface operable to capture the capture portion of the bone anchor and a spherical outer surface articulatable with the spherical seating surface;
a pressure insert disposed in the channel prior to the uploading of the capture portion of the bone anchor and including an upper surface operable to engage the elongate rod and a lower surface operable to engage the capture portion; and
a pair of opposed, semicircular-shaped biasing members having outer surfaces disposed adjacent inner cylindrical surfaces located on opposite sides of the axial bore below the discontinuous guide and advancement structure and configured for overlapping engagement with the pressure insert,
wherein upon the uploading of the capture portion of the bone anchor into the axial bore through the lower opening, the retainer is configured to capture and hold the capture portion within the receiver with the bone anchor extending downward through the lower opening and the pair of opposed biasing members are configured to bias the pressure insert against the capture portion to provide a pre-lock friction fit for the pivotal bone anchor assembly.