Patent ID: 12213704

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed embodiments are disclosed herein; however, it is understood that the following description is provided as being exemplary of the invention, which may be embodied in various forms without departing from the scope of the claimed invention. Thus, the specific structural and functional details provided in the description are non-limiting, but serve merely as a basis for the invention defined by the claims provided herewith.

Generally speaking, various embodiments of the present invention provide for a modular spinal fixation for orthopedic rod implantation. The invention is not limited to a specific size, diameter, or length and may accommodate a patient of any size, weight, and spinal condition. By way of example, the modular spinal fixation screw employs a pedicle screw that can vary in size, diameter, or length to accommodate the patient's needs. An advantage of the instant invention includes having a low profile spinal stabilization design capable of precise and reproducible linear engagement and disengagement.

Referring now to the Figures, illustrated is a preferred embodiment of the modular spinal fixation screw10. The modular spinal fixation screw10includes a bone screw12, also referred to as a pedicle screw, having a first end14and a second end16with a threaded shank18therebetween. The first end14of the bone screw12provides a penetrating tip used for entering and securing to pedicle bone structure. The second end16of the bone screw12forms a spherical head portion19. The modular spinal fixation screw10includes at least one continuous thread21on the threaded shank18protruding outwardly to engage with bone structure and provide stabilization of the joint. In a preferred embodiment, the modular spinal fixation screw10includes at least one helical thread21for penetration and engagement of the bone. The size, shape, and pitch of the continuous thread21are not limiting. The pitch of the threads21may be consistent or variable.

The modular spinal fixation a screw10includes connector20having a collet22operatively associated with a clamp24. Pins90,92coupled the collet22to the clamp24. The collet22has a lower end26spaced apart from an upper end28with a cylindrical shaped side wall30therebetween. The upper end26forms a header32which protrudes outwardly from the side wall30with a tapered section32extending from the side wall30to the upper end28. A u-shaped receptacle36extends beneath the upper end28and is constructed and arranged to receive a rod member100.

Now referring toFIG.5, the collet lower end26has an inner side wall38forming a receptacle surface40sized for coupling to the head portion19of the bone screw12. The receptacle surface40has at least one T-shaped living hinge42formed therein from a first relief cut44extending from the collet lower end26to a perpendicular positioned relief cut46juxtapositioned to the lower receptacle surface40. Moreover, a split line50extends between the receptacle surface40and the lower end26. The collet22also includes relief cuts placed between the living hinge42and the split line50. In a preferred embodiment, the collet22includes a first pair of relief cuts52,54placed between the living hinge42and the split line50and a second pair of relief cuts56,58placed between the split line50and the living hinge42.

The collet22provides proper seating of the head portion19along the receptacle surface40. The living hinge42and the relief cuts act in such a way whereby the collet22is able to slightly expand and contract to adapt to the shape and size of the head portion19. The design allows for the relief cuts to be strategically placed to facilitate attachment of the connector20to a bone screw12and ultimately lessen the resistance of the collet22for locking. In a preferred embodiment, the modular spinal fixation screw10includes side wall reliefs48to facilitate ease of inserting the collet22to the bone screw head portion19.

During assembly, pins90,92keep the connector20and the collet22together. The collet22includes a first and a second vertically disposed pin slot80,82extending along a length of the side wall30. Pins90,92are typically welded in the body, not shown. The pins limit the movement of the collet between an open position and a locked position.

Now referring toFIGS.4A and4B, the clamp24has an elongated body with an interior wall60and an exterior wall62. The interior wall includes at least one annular bulge64constructed and arranged to change the diameter of the collet22sidewall30when the clamp24is drawn over the collet22. Similar to the u-shaped receptacle36on the collet22, a rod slot70is constructed to accept a rod member100. In order to receive a rod member100, the rod slot70and the u-shaped receptacle36must be in line.

Likewise, the clamp24includes a first and a second pin hole84,86extending between the interior wall60and the exterior wall62. As shown inFIGS.6A to8B, a first pin90is coupled to the first pin hole84and extending into the first pin slot80, and a second in92is coupled to the second pin hole86and extending into the second pin slot82. The pins90,92regulate linear movement of the collet22to the length of each pin slot80,82. The pins90,92bottom out in the slots80,82which stops axial movement of the collet22and causes it to expand as the head portion19of the bone screw12continues to push up, as shown inFIG.6B.

The collet22is linearly traversable between a first position and a second position by application of a linear force applied along a longitudinal axis of the clamp24. Traversal of the collet22from the first position to the second position causes the collet22to cooperate with the at least one annular bulge64to apply concurrent compressive forces to simultaneously immobilize movement between the connector20and the rod member100and immobilize movement between the connector20and the bone screw12. The loading of the rod member100is shown inFIGS.10A and10Band the locking of the rod member100is shown inFIGS.11A and11B. In an alternative embodiment, the collet22includes at least one inner annular ridge66constructed and arranged to engage the at least one annular bulge64in an overlapping manner while the collet22is in the second position, whereby engagement of the at least one annual bulge64and the at least one annular ridge66applies compressive forces to the clamp24for immobilizing the clamp24to the head portion19of the anchored bone screw12. Further, in another construction, the collet22may include one inner annular surface67constructed and arranged to engage the at least one annular upper bulge65in an overlapping manner while the collet22is in the second position, whereby engagement of the at least one annular upper bulge65and the at least one annular surface67applies compressive forces to said clamp24for immobilizing said clamp24to said rod member100.

FIG.6Billustrates the modular spinal fixation screw with the clamp24in receipt of the collet22in an unlocked position with the connector being placed over the head portion19of the bone screw.FIG.7Billustrates the modular spinal fixation screw with the connector partially placed over the head portion19of the bone screw.FIG.8Billustrates the modular spinal fixation screw with the head portion19of the bone screw within the collet22, the pins90,92keeping the alignment of the collect22in response to the clamp24.FIG.9Billustrates the modular spinal fixation screw in axial alignment for receipt of a rod member with the connector in an unlocked position.FIG.10Billustrates the modular spinal fixation screw with rod member100placed within the collet22with the connector in an unlocked position.FIG.11Billustrates the modular spinal fixation screw in a locked position coupling the rod member100to the head portion19of the bone screw.

The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a device that “comprises,” “has,” “includes” or “contains” one or more elements, possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features.

It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.