US Patent 11672568 Spinal stabilization implant assemblies with interchangeable threaded closures

A bone anchor implant assembly configured for surgical implantation into a bone of a patient. The bone anchor implant assembly includes an elongate rod, a separate shank and head, and a closure mechanism configured as a one-part closure or two-part closure. The one-part closure and two-part closure are configured to be interchangeable with each other for closing a channel of the head and locking the assembly and the elongate rod between arms of the head with the closure mechanism.