US Patent Issued on March 18 for "Pivotal bone anchor assembly with biasing members for pre-lock friction fit" (Kansas Inventors)

ALEXANDRIA, Va., March 19 -- United States Patent no. 12,251,138, issued on March 18.

"Pivotal bone anchor assembly with biasing members for pre-lock friction fit" was invented by Roger P. Jackson (Prairie Village, Kan.) and James L. Surber (Kansas City, Kan.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A pivotal bone anchor assembly includes a pre-assembled receiver assembly and a bone anchor with a capture portion uploadable into the receiver assembly through a lower opening. The receiver assembly includes a receiver defining a channel for receiving a rod and an axial bore having a recess and a spherical seating surface above the lower opening. The receiver assembly also includes a retainer operable to c...