Rod reducer

#The present disclosure relates to a spinal deformity correction device and, more particularly, to a manually operated rod reducer for reducing a spinal rod into a bone screw in a controlled and measured manner.

#The spine is made up of a superposition of vertebrae that are normally aligned along a vertebral axis, extending from the lumbar vertebrae to the cervical vertebrae. There are many known spinal conditions, e.g., scoliosis, that require the imposition and/or maintenance of corrective forces on the spine in order to return the spine to its normal condition. When an individual's spine presents abnormal curvature, the vertebrae are inclined relative to one another and relative to the vertebral axis. The lateral edges of the vertebrae situated on one side are thus closer to one another and form a concave curve, while the lateral edges on the other side appear spaced apart from one another and form a convex curve. In order to straighten the spinal column, the lateral edges of the vertebrae on the concave side are spaced apart from one another and are taken relative to one another to a distance that is substantially equivalent to the distance between the lateral edges on the other side.

#In order to keep the vertebrae in that position relative to one another, numerous alignment devices have been developed for use in spinal fixation. One type of spinal construct may include, for example, one or more spinal rods that can be placed parallel to the spine with fixation devices (such as hooks, screws, or plates) interconnected between the spinal rods at selected portions of the spine.

#The above and other aspects and features of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

#FIG. 1 is an end view of a rod reducer in accordance with an embodiment of the present disclosure;

#FIG. 2 is an end view of the rod reducer of FIG. 1, illustrating the rod reducer partially actuated;

#Particular embodiments of the present disclosure will be described herein with reference to the accompanying drawings. As shown in the drawings and as described throughout the following description, and as is traditional when referring to relative positioning on an object, the terms “proximal” and “trailing” may be employed interchangeably, and should be understood as referring to the portion of a structure that is closer to a clinician during use. The terms “distal” and “leading” may also be employed interchangeably, and should be understood as referring to the portion of a structure that is farther from the clinician during use. In addition, the term “cephalad” is used in this application to indicate a direction towards a patient's head, whereas the term “caudad” indicates a direction towards the patient's feet. Further still, the term “medial” indicates a direction towards the middle of the body of the patient, while the term “lateral” indicates a direction towards a side of the body of the patient (i.e., away from the middle of the body of the patient). The term “posterior” indicates a direction towards the patient's back, and the term “anterior” indicates a direction towards the patient's front. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

#With reference to FIGS. 1-3, a rod reducer in accordance with an embodiment of the present disclosure is generally shown as a rod reducer 100. The rod reducer 100 may be utilized to reduce a spinal rod 200 (FIG. 18) into a slot 332 (FIG. 18) of a screw housing 330 of a bone screw 300. In particular, the rod reducer 100 provides a sleeve assembly 30 that enables quick release or engagement of the rod reducer 100 with the bone screw 300, which, in turn, reduces the time required for surgery and reduces the fatigue experienced by the clinician when compared with manually rotating a shaft 20 in order to disengage or engage the rod reducers 100 with the respective bone screws 300.

#With reference to FIGS. 3 and 4, the rod reducer 100 includes a shaft 20, the sleeve assembly 30 including a sleeve 35 and a nut 40, a housing 50, an anvil 60, and arm members 70. The shaft 20 includes an elongate body 22 having threads 22a configured to threadably engage the nut 40, as will be discussed below. The elongate body 22 includes a distal portion 24 defining an annular groove 24a configured to rotatably engage anvil 60, and a proximal portion 26 defining a cavity 26a having, e.g., a hex, key feature for non-slip engagement with a driver or other instrument (not shown) to drive the shaft 20. It is contemplated that cavity 26a may have any suitable configuration such as, e.g., slotted, square, star fitting, or a Phillips head, for engagement with the driver.