A pedicle screw (100, 200) comprising: a tulip head (8, 208) having an upper opening (81, 281) disposed in a top end (83, 283) of the tulip head (8, 208), a lower opening (82, 282) disposed in a bottom end (84, 284) of the tulip head (8, 208) opposite the upper opening (81, 281), and a pair of opposing arms (91, 291), wherein: the upper and lower openings (81, 82, 281, 282) form a single cavity extending through the tulip head (8, 208) from the top end (83, 283) to the bottom end (84, 284), the pair of opposing arms (91, 291) define a U-shaped channel (92, 292) transverse to the cavity, and the cavity has an interior wall, a retention groove (86, 286), and internal threads (94, 294), wherein the internal threads (94, 294) are disposed within the interior wall adjacent to the upper opening (81, 281) and the retention groove (86, 286) is disposed within the interior wall adjacent to the bottom end (84, 284) and extends around the perimeter of the lower opening; a rod seat (10, 210) disposed within the cavity, the rod seat (10, 210) having: a rod mating face (12, 212), a shank mating face (14, 214) opposite the rod mating face (12, 212), a hole (18, 218) disposed through the rod mating face (12, 212) and shank mating face (14, 214), and a pair of retention ledges (16, 216) engageable with the pair of opposing arms (91, 291) to prevent rotation of the rod seat (10, 210) relative to the tulip head (8, 208); a screw shank having a thread disposed along a length of the screw shank and a connector positioned at an upper end of the screw shank; a retainer collar (4, 204) having a collar body (41, 241), a pass-through aperture (48, 248) disposed through the collar body (41, 241), a collar expansion split (54, 254) disposed within the collar body (41, 241), and a locking ring groove (34, 234) disposed within an outer surface of the collar body (41, 241), wherein the retainer collar (4, 204) is disposed about the connector of the screw shank; and a locking ring (6, 206) disposed within the retention groove (86, 286) and the locking ring groove (34, 234). a tulip head (8, 208) having an upper opening (81, 281) disposed in a top end (83, 283) of the tulip head (8, 208), a lower opening (82, 282) disposed in a bottom end (84, 284) of the tulip head (8, 208) opposite the upper opening (81, 281), and a pair of opposing arms (91, 291), wherein: the upper and lower openings (81, 82, 281, 282) form a single cavity extending through the tulip head (8, 208) from the top end (83, 283) to the bottom end (84, 284), the pair of opposing arms (91, 291) define a U-shaped channel (92, 292) transverse to the cavity, and the cavity has an interior wall, a retention groove (86, 286), and internal threads (94, 294), wherein the internal threads (94, 294) are disposed within the interior wall adjacent to the upper opening (81, 281) and the retention groove (86, 286) is disposed within the interior wall adjacent to the bottom end (84, 284) and extends around the perimeter of the lower opening; the upper and lower openings (81, 82, 281, 282) form a single cavity extending through the tulip head (8, 208) from the top end (83, 283) to the bottom end (84, 284), the pair of opposing arms (91, 291) define a U-shaped channel (92, 292) transverse to the cavity, and the cavity has an interior wall, a retention groove (86, 286), and internal threads (94, 294), wherein the internal threads (94, 294) are disposed within the interior wall adjacent to the upper opening (81, 281) and the retention groove (86, 286) is disposed within the interior wall adjacent to the bottom end (84, 284) and extends around the perimeter of the lower opening; a rod seat (10, 210) disposed within the cavity, the rod seat (10, 210) having: a rod mating face (12, 212), a shank mating face (14, 214) opposite the rod mating face (12, 212), a hole (18, 218) disposed through the rod mating face (12, 212) and shank mating face (14, 214), and a pair of retention ledges (16, 216) engageable with the pair of opposing arms (91, 291) to prevent rotation of the rod seat (10, 210) relative to the tulip head (8, 208); a rod mating face (12, 212), a shank mating face (14, 214) opposite the rod mating face (12, 212), a hole (18, 218) disposed through the rod mating face (12, 212) and shank mating face (14, 214), and a pair of retention ledges (16, 216) engageable with the pair of opposing arms (91, 291) to prevent rotation of the rod seat (10, 210) relative to the tulip head (8, 208); a screw shank having a thread disposed along a length of the screw shank and a connector positioned at an upper end of the screw shank; a retainer collar (4, 204) having a collar body (41, 241), a pass-through aperture (48, 248) disposed through the collar body (41, 241), a collar expansion split (54, 254) disposed within the collar body (41, 241), and a locking ring groove (34, 234) disposed within an outer surface of the collar body (41, 241), wherein the retainer collar (4, 204) is disposed about the connector of the screw shank; and a locking ring (6, 206) disposed within the retention groove (86, 286) and the locking ring groove (34, 234).