Sequential reducer

1 . A surgical assembly, comprising:

a unitary outer sleeve defined by a tubular central portion extending from a proximal end to a distal end and having a sidewall that circumscribes an inner channel, the proximal end having one or more flats oriented around a circumference thereof, and the distal end terminating in a pair of extensions configured to receive a bone anchor therebetween;

an inner sleeve having a proximal threaded portion and a distal translating portion configured to pass through the inner channel of the outer sleeve; and

a pair of pivoting arms received in the outer sleeve, the pair of pivoting arms each extending from a proximal end having an actuator formed thereon to a distal end that is configured to extend into the inner channel to couple the outer sleeve to the bone anchor.

2 . The assembly of claim 1 , wherein the outer sleeve further comprises a circumferential groove that extends around a circumference of the outer sleeve to facilitate engagement of one or more instruments to the sidewall of the outer sleeve.

3 . The assembly of claim 2 , wherein the circumferential groove is distal to the one or more flats.

4 . The assembly of claim 1 , wherein the inner channel comprises one or more mating features having a threaded inner surface configured to cooperate with one or more instruments disposed within the inner channel.

5 . The assembly of claim 1 , further comprising a counter-torque device having a mating feature that corresponds to the one or more flats for coupling thereto.

6 . The assembly of claim 1 , wherein the pivoting arms are spring-loaded to bias to a closed position wherein the distal ends of the pivoting arms extend into the inner channel.

7 . The assembly of claim 1 , wherein the outer sleeve further comprises a pair of opposed longitudinal recesses configured to receive a portion of the pair of pivoting arms therein.

8 . The assembly of claim 7 , wherein the distal end of each pivoting arm is received in one of the opposed longitudinal recesses and the proximal end of each pivoting arm is disposed outside of the outer sleeve.

9 . The assembly of claim 7 , wherein an inner surface of the proximal end of each pivoting arm is disposed outside of the outer sleeve.

10 . The assembly of claim 9 , wherein the inner surface of the proximal end of each pivoting arm is positioned proximally to the pair of opposed longitudinal recesses.

11 . The assembly of claim 1 , wherein the distal translating portion further comprises one or more longitudinal grooves that extend along a length thereof.

12 . The assembly of claim 11 , wherein at least one pivoting arm includes a protrusion that is configured to extend into the one or more longitudinal grooves of the distal translating portion of the inner sleeve to mate thereto.

13 . The assembly of claim 1 , wherein the one or more flats are recessed relative to an outer surface of the sidewall.

14 . A surgical assembly, comprising:

an outer sleeve defined by a tubular central portion extending from a proximal end to a distal end and having a sidewall that circumscribes an inner channel, the proximal end having one or more flats oriented around a circumference thereof, and the distal end terminating in a pair of extensions configured to receive a bone anchor therebetween;

an inner sleeve having a proximal threaded portion and a distal translating portion configured to pass through the inner channel of the outer sleeve; and

a pair of pivoting arms received in the outer sleeve, the pair of pivoting arms each extending from a proximal end having an actuator formed thereon to a distal end that is configured to extend into the inner channel to couple the outer sleeve to the bone anchor;

wherein the outer sleeve further comprises a circumferential groove that extends around a circumference of the outer sleeve to facilitate engagement of one or more instruments to the sidewall of the outer sleeve.

15 . The assembly of claim 14 , wherein the circumferential groove is distal to the one or more flats.

16 . The assembly of claim 14 , wherein the inner channel comprises one or more mating features having a threaded inner surface configured to cooperate with one or more instruments disposed within the inner channel.

17 . The assembly of claim 14 , wherein the one or more flats are recessed relative to an outer surface of the sidewall.

18 . A surgical assembly, comprising:

an outer sleeve defined by a tubular central portion extending from a proximal end to a distal end and having a sidewall that circumscribes an inner channel, the proximal end having one or more flats oriented around a circumference thereof, and the distal end terminating in a pair of extensions configured to receive a bone anchor therebetween;

an inner sleeve having a proximal threaded portion and a distal translating portion configured to pass through the inner channel of the outer sleeve; and

a pair of pivoting arms received in the outer sleeve, the pair of pivoting arms each extending from a proximal end having an actuator formed thereon to a distal end that is configured to extend into the inner channel to couple the outer sleeve to the bone anchor;

wherein the one or more flats are recessed relative to an outer surface of the sidewall.

19 . The assembly of claim 18 , wherein the outer sleeve further comprises a circumferential groove that extends around a circumference of the outer sleeve to facilitate engagement of one or more instruments to the sidewall of the outer sleeve.

20 . The assembly of claim 19 , wherein the circumferential groove is distal to the one or more flats.

21 . The assembly of claim 18 , wherein the inner channel comprises one or more mating features having a threaded inner surface configured to cooperate with one or more instruments disposed within the inner channel.