Set screws for femoral nails

Abstract

To provide a set screw for use in an intramedullary fracture fixation device having a longitudinal axis.SOLUTION: The set screw may include a body with an external thread, and an elastic member extending from the body, the elastic member having an uncompressed condition and a compressed condition. The housing may include a sidewall that partially surrounds a longitudinal axis and defines a cavity for receiving the set screw. Thereby, when the set screw is at least partially disposed within the cavity and is in the uncompressed condition, the set screw is secured to the housing and is rotatable about the longitudinal axis relatively to the housing.SELECTED DRAWING: Figure 9E

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is filed on May 1, 2009, the disclosures of which are incorporated herein by reference. The August 2020 application entitled "Rew for Femoral Nail" U.S. Provisional Application No. 63 / 065,208, filed on the 13th, and U.S. Provisional Application No. 63 / 065,208, filed on March 6, 2020. This application claims the benefit of the filing date of U.S. Provisional Application No. 62 / 986,138, filed on That is why.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to intramedullary devices for internal fixation of fractured long bones. [Background technology]

[0003] Femoral fractures often occur at the femoral neck and trochanter. The fracture is usually fixed with an intramedullary rod (sometimes an intramedullary nail) with a beveled opening to receive a cervical screw. Intertrochanteric fractures are treated using intramedullary intertrochanteric fracture fixation devices, including intratrochanteric nails (also called femoral nails). The neck screw is inserted into the bone to compress and stabilize the fractured bone segments together during bone formation. It is designed to bridge the fracture line and transfer the load from the femoral head into the shaft of the femoral nail. It is being done.

[0004] The intramedullary nail is intended to be inserted into the medullary canal of the femur over a guidewire. The guide wire is used to guide the fractured bone parts when the intramedullary nail is inserted into the bone's medullary cavity. Once the intramedullary nail has reached its intended position in the medullary canal, The guide wire may be removed, allowing the neck screw to be guided through the beveled opening in the femoral nail. A fastening member, such as a set screw, can then be inserted through the intertrochanteric bone. The cervical screw is fastened to the nail by being inserted through an axial hole formed in the proximal portion of the internal nail. To conclude.

[0005] If the fractured bone fragments rotate and move after surgery, complications such as shortening of the femoral neck may occur. This may cause a decline in bodily functions. Therefore, during surgery, the fracture site is compressed and then stabilized, It is desirable to minimize postoperative rotational movement during the bone healing phase. Considering the load transfer that may occur when the weight of the patient is applied to the hip joint, It may be advantageous to allow limited axial sliding of the cervical screw.

[0006] Despite the improvements that have been made to intramedullary intertrochanteric fracture fixation devices, various drawbacks remain. For example, conventional set screws block the axial hole, which means The set screw must be inserted until the intramedullary nail is embedded in the bone medullary cavity and the guide wire is removed. This means that the soft tissue cannot be inserted into the proximal end of the axial hole. Because of the frequent overlap, tightening the set screw to the cervical screw is practical during surgery. This is problematic when performing drilling in an axial hole as it can be a time consuming process. The reamed bone fragment, placed in the femoral nail, engages the threads of the set screw with the corresponding threads of the femoral nail. Furthermore, improper set screws can make the already difficult task of fixing the If the set screw is screwed in too quickly, the threads of the set screw or the threads of the intramedullary nail may be damaged. This may lead to back-out of the set screw and post-operative realignment of the fractured bone segments. This may result in a shift. Summary of the Invention

[0007] According to a first aspect of the present disclosure, there is provided a method for fixing a bone fracture using an intramedullary intertrochanteric fracture fixation device. The cannulated set screw assembly is provided by the manufacturer or Other users pre-operate by tightening the set screw assembly to the corresponding threads in the femoral nail. This allows for reduced errors and shorter surgery times.

[0008] The set screw assembly has a longitudinal axis and includes a set screw, a housing, and The set screw includes a body having external threads and a resilient member extending from the body. The housing may have a longitudinal axis and a resilient member having an uncompressed state and a compressed state. a side wall partially surrounding the base and defining a cavity for receiving a set screw. whereby, when the set screw is at least partially disposed within the cavity, The set screw is fixed to the housing and is rotatable relative to the housing.

[0009] According to another aspect of the present disclosure, an intramedullary intertrochanteric fracture fixation device includes an intramedullary nail, a neck screw, and The intramedullary nail includes a proximal portion adjacent the proximal end and a set screw assembly adjacent the distal end. The proximal portion may include a tapered opening and a distal portion having a longitudinal axis. an axial hole that extends through the proximal end of the nail into the beveled opening; defining a bore, an internal thread, and a slot extending substantially parallel to the longitudinal axis; The neck screw may extend through the angled opening and have an outer surface with grooves. The set screw may be disposed within an axial hole of the intramedullary nail. , may include a housing having an upper portion and a lower portion, the upper portions collectively defining a cavity The set screw engages the internal threads. The set screw may include an external thread that fits at least partially inside the cavity of the housing. The set screw may be positioned so that it can be rotated relative to the housing. As the set screw is rotated, the set screw and housing move longitudinally together.

[0010] In yet another aspect of the present disclosure, an intramedullary intertrochanteric fracture fixation device includes an intramedullary nail, a cervical screw, and , and a set screw assembly. The intramedullary nail includes a proximal portion adjacent the proximal end and a distal portion adjacent the distal end. The proximal portion may have a tapered opening and a distal portion that is in contact with the proximal end of the nail. and defining an axial bore extending into the angled opening, an internal thread, and a slot. The axial bore may have a longitudinal axis. The neck screw extends through the angled opening. The set screw assembly may be inserted to receive a guide wire. The tubular design allows pre-operative assembly inside the proximal portion of the intramedullary nail. stomach. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a femur. [Figure 2] FIG. 1 is an anterior-posterior front view of a proximal femur with a fractured femoral neck. [Figure 3]FIG. 1 is a cross-sectional view of an intramedullary intertrochanteric fracture fixation device including an intramedullary nail, a neck screw, and a set screw assembly according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a side perspective view of the intramedullary nail shown in FIG. 3. [Figure 5A] FIG. 5 is a cross-sectional view of the intramedullary nail shown in FIG. 4 taken along line AA. [Figure 5B] FIG. 5 is a cross-sectional view of the intramedullary nail shown in FIG. 4 taken along line BB. [Figure 6A] FIG. 4 is a side view of the set screw assembly shown in FIG. 3. [Figure 6B] FIG. 4 is a top view of the set screw assembly shown in FIG. 3. [Figure 7] FIG. 6C is an exploded view of the set screw assembly shown in FIGS. 6A and 6B. [Figure 8] FIG. 4 is a partial cross-sectional view showing a guide wire extending through the set screw assembly and intramedullary nail shown in FIG. 3. [Figure 9A] FIG. 10 is a perspective view of a set screw assembly according to another embodiment of the present disclosure. [Figure 9B] FIG. 9B is a top view of the set screw assembly of FIG. 9A. [Figure 9C] 9C is a cross-sectional view, taken orthogonal to the longitudinal axis, of an intramedullary nail configured to receive the set screw assembly of FIGS. 9A and 9B according to another embodiment of the present disclosure. FIG. [Figure 9D] FIG. 9C is a perspective view of a modified embodiment of the set screw assembly of FIGS. 9A and 9B. [Figure 9E] FIG. 9C is an anterior-posterior side view of a modified embodiment of the set screw assembly of FIGS. 9A and 9B. [Figure 9F] FIG. 9C is a bottom perspective view of a housing of a modified embodiment of the set screw assembly of FIGS. 9D and 9E. [Figure 9G] FIG. 9C is a bottom perspective view of a housing of a modified embodiment of the set screw assembly of FIGS. 9D and 9E. [Figure 9H] 9D and 9E are cross-sectional views along the longitudinal axis illustrating the engagement between the neck screw and the set screw assembly of FIGS. 9D and 9E. [Figure 10]10A-10F are plan views of exemplary set screw assemblies according to other embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] As used herein, when referring to a femoral or intramedullary nail, the term "proximal" When the intramedullary nail is implanted into the patient's medullary canal in the intended manner, the femur or intramedullary nail The term "distal" does not mean the end of the vein that is closer to the heart. When the intramedullary nail is implanted inside the patient's medullary canal, the femur or the intramedullary nail is positioned further from the heart. The term "front" means the front part of the body or the side facing the face; The term "posterior" means the side facing the back of the body. The term "medial" means the side facing the front of the body. The term "lateral" means the side facing the midline, and the term "lateral" means the side facing away from the midline of the body. When referring to cervical screws, the term "posterior" means the side closer to the user. The term "front" means the side further away from the user. When referring to a product, the terms "substantially," "generally," and "about" are used to denote deviations from absolute. Minor deviations are meant to be encompassed within the scope of the term so modified. This is what is intended.

[0013] Throughout this disclosure, fractures refer to fractures of the femoral neck, however, the devices described below may be used to treat fractures of the bone. The femur, whether the fracture is natural or surgeon-induced For associated fractures of the diaphysis, and for fractures in other long bones such as the tibia or humerus can also be used for fastening.

[0014] FIG. 1 illustrates a femur 10 and its six anatomical regions: the diaphysis or mid-diaphysis 12 , proximal metaphysis 14, distal metaphysis 16, proximal epiphysis or head 18, distal epiphysis 20, and femoral head The femur 10 includes a hard cortex 24 and a medullary cavity 26. The medullary cavity 26 is defined by the center of the diaphysis 12, the proximal metaphyseal region 30 and the distal metaphyseal region 32, and the proximal It includes an epiphyseal region 34 and a distal epiphyseal region 36, and a medullary cavity 28 extending therethrough.

[0015] FIG. 2 shows an anterior-posterior view of the proximal femur 10 having a fracture 38 extending along the femoral neck 22. The fracture 38 breaks the proximal femur through the first bone fracture located adjacent to the proximal metaphysis 14. and a second bone portion 42 located adjacent the proximal epiphysis or head 18. Fracture 38 is an exemplary illustration of an unstable extra-articular fracture, i.e., the bone The fracture is located outside the joint. This type of fracture can lead to fracture if not treated. This can lead to long-term complications, including fracture (i.e., bone pulverization) of the femoral neck. This can result in shortening of the 22 and severe pain.

[0016] FIG. 3 illustrates an intramedullary intertrochanteric fracture fixation device 100 according to one embodiment of the present disclosure. The device 100 is adapted to connect the first bone portion 40 and the second bone portion 42 (FIG. 1) during the healing phase of the fracture 38. and 2) to further provide rotational stability between the first and second bone portions. The device 100 is designed to maintain stability from the outside to the inside. An intramedullary nail 102 having a beveled opening 104 (shown in FIG. 4) extending therethrough and a fractured bone. A cervical screw 1 that can be inserted through a beveled opening to compress bone portions together 06 and a set screw for rotationally stabilizing the cervical screw within the beveled opening of the intramedullary nail. 200, inclusive.

[0017] Referring to FIG. 4, the intramedullary nail 102 includes a proximal portion 108, a distal portion 110, and a distal portion 112. and a middle portion 112 located between and connecting the distal portion. The rod-shaped body of the intramedullary nail 102 is adapted to insert the intramedullary nail into the medullary cavity 28 of the femur 10 (see FIG. 1). For this reason, the intermediate Section 112 may be curved and tapered from proximal to distal.

[0018] The rod-shaped body of the intramedullary nail 102 is cannulated and inserted into the medullary cavity 28 of the femur 10 (FIG. 1 It receives surgical wires, such as K-wires, to guide the intramedullary nail into the correct position within the graft (shown in The nail 102 defines a channel 114 configured to receive the proximal portion 108 and the The distal portion 110 has a substantially circular cross section along its entire length so that the distal portion 110 is substantially cylindrical. The proximal portion 108 of the intramedullary nail 102 may have a face to accommodate the beveled hole 104. The distal portion 110 of the nail 102 has a diameter smaller than the diameter of the proximal portion 108. The intramedullary nail has a small diameter that allows for easy insertion of the distal portion of the intramedullary nail into the medullary canal of the femur. For the same reason, the trochanteric 12 is anatomically shaped relative to the medullary cavity 28 of the femur 10. Additionally, the distal portion 110 of the intramedullary nail 102 has a conical tip 116 at its distal end. The distal portion 110 of the nail 102 also serves to fasten the intramedullary nail to the diaphysis 12 of the femur 10 after implantation. The bone fastener defines an opening 118 configured to receive a bone fastener, such as a locking screw, for example. That's fine.

[0019] As shown in FIGS. 5A and 5B, the intramedullary nail 102 has a proximal end of the intramedullary nail and a beveled opening 1 04, an axial direction extending along the longitudinal axis L of the proximal portion 108 of the intramedullary nail The axial bore 122 is located on the set screw assembly 200 (shown in FIG. 3). The screw includes internal threads 126 configured to engage corresponding threads on the screw.

[0020] The angled opening 104 has a hole axis that is oblique to the axial extension of the proximal portion. The proximal portion 108 is angled laterally relative to the longitudinal axis L of the proximal portion 108 so as to have an extension line for In other words, the bore axis 124 of the angled opening 104 is The proximal portion 108 is oriented obliquely relative to the longitudinal axis L of the proximal portion 108. The bore axis 124 of the port 104 is inclined at an angle α relative to the longitudinal axis L of the proximal portion 108. The angle α may be about 90° to about 140°, for example, about 126°. Good too.

[0021] Returning to FIG. 3, the neck screw 106 is inserted through the angled opening 104 from the lateral to the medial direction. As will be described in more detail below, the neck screw 106 is configured such that the neck screw has an angled opening. The neck screw is inserted into the hole 104 in a manner that prevents rotation within the hole 104 and takes into consideration load transfer. via set screw 200 in a manner that allows limited sliding along line 124 (shown in FIG. 5A). and is coupled to the intramedullary nail 102.

[0022] The neck screw 106 includes a rear end 128 and a front end 130. 8 is configured to receive the tip of a tool such as a screwdriver or wrench. The front of the neck screw 106 includes a recess 132 that is a hexagonal internal drive feature. The screw may include threads 134, e.g., coarse threads, for anchoring the screw into the intertrochanteric bone. The outer circumferential surface of the neck screw 106 extends in a direction substantially parallel to the longitudinal axis of the neck screw. For example, the neck thread 106 may have a plurality of grooves 136 extending around the circumference of the neck thread. The grooves 136 may include four grooves 136 spaced circumferentially at 90° intervals. Each groove 136 has a shallow The distal end defines an upslope having a deep end and a deep end. The upslope extends posterior to the cervical screw 106. The longitudinal axis of the neck screw 106 extends from the anterior portion of the neck screw 106 to the anterior portion of the neck screw 106. By being substantially coaxial with the bore axis 124 of the angled opening 104, the neck screw At the same time, the fracture 38 is secured to the bone so as to transfer the load located on the head of the bone to the intramedullary nail 102. The first bone portion 40 and the second bone portion 42 are compressed together to form a bridge. It is composed of:

[0023] As shown in FIGS. 6A to 8, the set screw assembly 200 is of the cannulated type. This eliminates the drawbacks associated with set screws described with respect to the prior art, i.e., the difficulties associated with assembly during surgery. The set screw assembly 200 is of the cannulated type, The set screw assembly may be pre-assembled into the intramedullary nail 102 and placed within the intramedullary nail. The catheter may be configured to receive a guidewire in a deployed position, i.e., during surgery. The surgeon inserts the intramedullary nail 102, which houses the set screw assembly 200, into the guide. It can be inserted through a wire into position within the patient's intrathecal cavity. The term "pre-operatively assembled" refers to the assembly of the set screw 200 in the intertrochanteric position. The fracture fixation device 100 is assembled into an intramedullary nail 102 by the manufacturer before shipping. or alternatively, the set screw assembly is implanted into the intrathecal canal of the patient. This means that the nail is assembled into the nail by the user before it is inserted.

[0024] Set screw assembly 200 includes a housing 202 and a set screw 204. As shown in FIG. 8B, the cannulation point 206 is aligned with the longitudinal axis of the set screw assembly 200. The intubation point 206 extends along a line, and a set screw is disposed within the housing and fixed. When the female screw is pre-assembled within the intramedullary nail 102, the set screw assembly The housing 202 and the set screw assembly are configured to receive the guide wire. The set screw 204 extends completely through the casing.

[0025] Referring to FIG. 7, the housing 202 includes an upper portion 208 and a lower portion 210. The upper portion 208 of the housing 202 includes a first end wall 212 and a a spaced apart second end wall 214 and a spaced apart second end wall 215 extending between the first and second end walls; and a side wall 216 partially surrounding the intubation site 206 in the upper portion. In other words, the sidewall 216 defines the longitudinal axis of the set screw assembly 200. Thus, the first end wall 212 of the upper portion 208 and The second end wall 214 and the side wall 216 in combination are sized to receive the set screw 204. In a preferred embodiment, the first end wall 212 defines a cavity 218 configured as shown in FIG. 2, includes a lip 219 for retaining the set screw 204 within the cavity 218. .

[0026] The upper portion 208 of the housing 202 has a ledge at the junction of the upper and lower portions. 220 is formed having a cross section larger than that of the lower portion 210 of the housing. In addition, the cross section of the upper portion 208 of the housing 202 is polygonal in shape. As used herein, the term "polygon" or "polygonal" refers to a complete It is defined as any shape that is not circular and contains one or more vertices 222. 22 may form a sharp point or may be rounded. For example, in FIG. As shown, the upper portion 208 of the housing 202 may have a substantially triangular cross section. Often contains rounded vertices.

[0027] With further reference to FIG. 5B, the proximal portion 108 of the intramedullary nail 102 is inserted through the axial bore 1 of the intramedullary nail. The wall defining the axial bore 122 includes a seat 138 extending inwardly from the wall defining the axial bore 122. also includes a longitudinal slot extending substantially parallel to the longitudinal axis of the axial bore. The longitudinal slots 140 define corresponding vertices 222 of the housing 202. 102. The set screw assembly is shaped and sized to receive the set screw. When installed, the set screw assembly 200 functions as a track to stabilize the set screw assembly 200. Additionally, after the set screw assembly 200 is secured to the intramedullary nail 102, The apex 222 is located within the longitudinal slot 140, thereby allowing the axial hole 1 Unwanted post-operative rotation of the set screw assembly within 22 is prevented.

[0028] The lower portion 210 of the housing 202 is substantially cylindrical in shape and The protrusions 224 include one or more protrusions 224 extending from a distal end 226. The protrusions 224 may include a beveled opening. Extending into the mouth 104 and into one groove 136 of the neck screw 106 The distal end 226 of the lower portion 210 is sized and shaped to fit a set screw assembly. It may be angled obliquely relative to the longitudinal axis of the assembly 200. In an embodiment, this angle is such that when the shelf 220 of the housing 202 contacts the seat 138 , α (e.g., , the bore axis 124 of the angled opening 104 and the longitudinal axis of the proximal portion 108 of the intramedullary nail 102 L and the angle between the housing 20 The distal end 226 of the lower portion 210 of the nail 102 extends into the beveled opening 104 of the nail 102. and does not come into contact with the outer surface of the neck screw 106.

[0029] Set screw 204 is a substantially circular screw with external threads 230 disposed around its body. The set screw 204 has a cylindrical body 228. The set screw threads 230 (shown in FIG. 6B) and allowing the set screw assembly 200 to protrude from the cavity (as shown in FIG. 1). The threads 230 of the set screw are threadedly engaged with the nail 102 (as shown in FIG. 8). At least one screw thread is inserted into the cavity 218 of the housing 202 so as to engage the internal threads 126. The size is such that it can receive partial damage.

[0030] The set screw 204 is transitionable between an expanded (e.g., uncompressed) state and a compressed state. In a compressed state, the set screw 204 is secured to the first end of the housing 202. The axial length is equal to or less than the distance between the first end wall 212 and the second end wall 214. When the resilient member 232 is in a compressed state, the set screw 204 is inserted into the cavity 218. On the other hand, when the elastic member 232 is in an expanded state, the axial length of the set screw 204 The length is greater than the distance between the first end wall 212 and the second end wall 214 of the housing 202. As a result, the set screw 204 is positioned within the cavity 218 and the elastic member 232 expands. When friction-fitted into engagement with the first end wall 212 and the second end wall 214 of the housing 202, The set screw is positively coupled to the housing, preventing outward movement of the set screw relative to the housing. The engagement between the set screw 204 and the housing 202 also prevents the set screw from Prevents unintentional rotation within the housing and prevents intentional rotation of the set screw. This increases the torque required to

[0031] The elastic member 232 is secured to the set screw 20 so that a retaining step 242 is formed around the elastic member. The retaining shoulder 242 may have a cross section smaller than the cross section of the main body 228 of the housing. 219 of the lug, thereby removing the set screw 204 from the housing 202. 218. The set screw 218 is securely fastened to the inside of the cavity 218. Subsidies may be available.

[0032] As shown in FIG. 7, the elastic member 232 is integrally formed on the end of the set screw 204. is a flange attached to the end of the set screw 204. The flange is The flange has a first or attached end 234 and a second or non-attached end 236. One end 234 is located at the end of the body 228 of the set screw 204 on the first outer side of the intubation site 206. The flange extends from the end of the tube such that the second or non-attached end 236 is opposite the intubation site. Orient the cannulation point of the set screw so that it is positioned beyond the end of the set screw on the outer side of the tube. The second end 236 of the flange is attached to the body 228 of the set screw 204. By not being attached, the second end (e.g., the non-attached end) of the flange and the body A gap 238 is formed between the end of the are.

[0033] The flange may be made of any material that exhibits elasticity, such as metal, metal alloy, or rubber. In this manner, during insertion of the set screw 204 into the cavity 218, a first end wall 212 of the flange 202, or the like, with respect to the second end 236 of the flange. When a force is applied in the direction of the arrow, the second end of the flange contacts the end of the body 228 of the set screw 204. , thereby reducing the size of the gap 238 and The axial length of the set screw 202 is then reduced. After being inserted into cavity 218, the elastic material will expand, thereby , the set screw is secured inside the cavity.

[0034] The flange described above is merely one example of the elastic member 232. It will be understood that any other resilient material may be substituted, such as rubber, silicone, etc. Additionally, the resilient member 232 is configured such that compression and expansion of the resilient member is controlled by the cavity 218 of the housing. As long as the set screw is securely engaged within the The integral set screw 204 is preferably a set screw that is rotatable within the cavity when the set screw is engaged. or may be integrally formed as a component of the set screw 204 or housing. It may be attached to the main body of the ring 202, which is a separate member.

[0035] Referring to FIG. 6B, the resilient member 232 and / or the intubation site 206 of the set screw 204 is designed to receive the tip of a tool, such as a screwdriver or hex key (not shown). Further, by rotating the set screw in a first direction, the set screw assembly The assembly 200 is threaded distally into the axial bore 122 to couple with the intramedullary nail 102. drive feature 24, such as a recessed hexagonal lobe-type internal drive feature, configured to Of course, the tip of the tool can also be inserted into the drive feature 240. and may be rotated in a second direction opposite to the first direction, thereby rotating the set screw 20 4 is moved proximally through the axial bore 122 to unscrew the set screw from the intramedullary nail 102. You may also release the

[0036] Next, the use of the intramedullary intertrochanteric fracture fixation device 100 to treat the fracture 38 will be described. First, the set screw 204 is inserted into the cavity 218 of the housing 202. The set screw assembly 200 is assembled by the above steps. 232 is the uncompressed point at which the elastic member contacts the first end wall 212 of the housing 202. More specifically, the first end wall of the housing 202 transitions from a compressed state to a compressed state. 212 applies a distal force to the unattached end 236 of the flanged resilient member 232. This compresses the non-attached end toward the distal end of the body 228 of the set screw 204. The compression of the set screw 204 reduces the size of the gap 238, which in turn reduces the axial length ( For example, from the non-attached end 236 of the flange to the opposite end of the body 228, (measured length) to advance the set screw into cavity 218. The set screw 204 passes through a lip 219 on the upper portion 208 of the housing 202. After the lip 219 is compressed, the elastic member 232 expands elastically. It seats within the retention shoulder 242 and frictionally secures the set screw 204 within the cavity 218. The engagement between the cap 219 and the retaining shoulder 242 is maintained by the set screw 204 relative to the housing 202. When a rotational force is applied to the set screw, the set screw The shaft 214 is adapted to rotate about its longitudinal axis within the cavity 218.

[0037] The set screw assembly 200 is then inserted into the proximal portion 108 of the intramedullary nail 102 as previously described. At the start, the manufacturer or another user may assemble the top of the housing 202. One of the points 222 may be positioned into the longitudinal slot 140 of the intramedullary nail 102. Once positioned, the set screw assembly 200 is threaded onto the external threads 23 of the set screw 204. 10 may be slid distally until it engages the internal threads 126 of the intramedullary nail 102. As described, the set screw assembly 200 is inserted into the axial bore 122 of the intramedullary nail 102. Sliding prevents the set screw assembly from tilting relative to the longitudinal axis This allows the external threads 230 of the set screw 204 and the internal threads of the intramedullary nail to interlock. This helps to properly align the ridges 126. 02, the possibility of damaging either thread is reduced. do.

[0038] A driving tool (not shown) is then inserted into the recessed drive feature 240 of the set screw 204. The set screw and the intramedullary nail may be inserted into the stent and rotated in a first direction (e.g., clockwise). 102 to threadably engage the set screw assembly 200 distally within the axial bore 122. When the set screw 204 is rotated, the components of the set screw assembly 200 The components of the intramedullary nail 102 are: 1) the apex 222 of the housing 202 and the length of the intramedullary nail. The engagement between the longitudinal slot 140 and the housing prevents rotation of the housing within the axial bore. 2) engagement between the expanded set screw 204 and the housing (the lip of the housing) 219 and the retaining shoulder 242 of the set screw) is inserted into the housing cavity 2. 18, a configuration that prevents the set screw from moving axially or outwardly (on the other hand, 3) rotational movement of the set screw within the cavity is permitted; and 4) external thread of the set screw 204. The engagement between the threads 230 and the internal threads 126 of the intramedullary nail 102 causes the set screw, and thus or a configuration that moves the housing 202 distally within the axial bore 122. The rotation of the set screw 204 rotates the protrusion 220 of the lower portion 210. 24 may be stopped before extending into the beveled opening 104 of the intramedullary nail 102.

[0039] With the intramedullary intertrochanteric fracture fixation device 100 prepared for surgery, the surgeon then: , via the guide wire 244, the intramedullary nail 102 is inserted into the cannulated nail (as shown in FIG. 8). The same assembly 200 may be advanced into position within the patient's intramedullary canal 28. After the nail 102 is positioned within the medullary canal 28 of the femur 10, the surgeon inserts the guide wire 2 44 may be removed and the bevel of the intramedullary nail may be removed to compress the fractured bone segments together. A neck screw 106 may be inserted through the opening 104 .

[0040] After the surgeon has confirmed that the neck screw 106 is properly positioned into the intertrochanteric bone, The drive tool is again used to reposition the ledge 220 of the housing 202 against the seat of the intramedullary nail 102. 138. Rotate the set screw 204 to move the set screw assembly 200 distally until it engages the set screw 204. axially, thereby driving the protrusion 224 further into the beveled opening 104 of the nail. , extending into one of the grooves 136 of the neck screw 106. After being positioned in the groove 136 The protrusion 224 prevents the neck screw 106 from rotating about the hole axis 124. Together, they effectively prevent the neck screw 106 from rotating within the angled opening 104 .

[0041] Next, the surgeon optionally adjusts the axial movement of the neck screw 106 relative to the intramedullary nail 102. To set this limit, the surgeon may choose to limit the desired limit. The set screw 204 may be rotated by using a driving tool during surgery until the set screw 204 reaches the If the surgeon desires to reduce the axial movement of the neck screw 106, The surgeon rotates the drive tool in a first direction (e.g., clockwise) to perform the above-described 1. As shown, the set screw assembly 200 may be moved distally within the axial bore 122. As a result, the protrusion 224 protrudes further into the inclined groove 136 of the neck screw 106, which This limits the distance that the neck screw can slide. When the screw 106 is securely engaged with the surface defining the groove 136, the neck screw Migration can be completely prevented.

[0042] On the other hand, the surgeon may wish to allow or increase the axial sliding of the cervical screw 106. If the surgeon desires to rotate the set screw 204 in a second direction (e.g., counterclockwise), 3. Rotating the set screw assembly 200 proximally during surgery (around the Such movement may retract the protrusion 224 away from the neck screw 106. This allows the neck screw to rotate axially before contacting the inclined groove 136 of the neck screw. This allows for a relatively large amount of sliding.

[0043] 9A-9C show an alternative intramedullary nail 102' and an alternative set screw assembly. The intramedullary nail 102' and set screw assembly 200' are shown. Regarding the intramedullary nail 102 and set screw assembly 200 of the intertrochanteric fracture fixation device 100 It includes all of the features described above and is further modified as described below. The sidewall 216' of the ring 202' may, for example, be configured to allow the set screw assembly 200' to fit into the axial bore 12. When placed into the pulp 2′, the external threads 230′ of the set screw 204′ pass through the opening. An opening 225' is provided which allows direct engagement with the internal thread 126' of the internal nail 102'. 9B, the housing 202' includes a pair of recessed notches defining When viewed perpendicular to the longitudinal axis, the shape is substantially triangular and has a trefoil cross section. It has a cross-sectional shape like a bar.

[0044] The lower portion of the housing 202' is different from the housing 202 shown in FIGS. Alternatively, as shown in Figures 9D to 9H, the housing The lower portion 210' of the lug 202' may be cylindrical in shape and may be attached to the set screw assembly 2 One or more outwardly tapered surfaces 2 that facilitate insertion of a k-wire through the The distal end of the housing 202' may include a distal end 226' formed by a 226' also includes an inner protrusion 224a' and an outer protrusion 224b'. 24a' and outer projection 224b' are curved, more specifically medial-lateral. When viewed from this perspective, the shape is parabolic. The projections 224a', 224b' are designed to reduce stress on the projections 224a', 224b' when engaged with the There are.

[0045] The outer protrusion 224b' extends more distally than the inner protrusion 224a'. Thus, the fracture fixation device is assembled as shown in FIG. 9H, with the medial projection 224a′ and and outer projection 224b' when positioned within groove 136' of neck screw 106'. The inner projection engages with the bottom surface of the groove, causing the inner projection to float above the bottom surface of the groove. In other words, the inner projection 224a' prevents the neck screw 106' from rotating within the axial bore. Therefore, the groove 136' extends partially into the groove 136' but does not engage the bottom surface of the groove. Therefore, when the neck screw slides along the hole axis, it slides against the bottom surface of the groove. As a result, the inner protrusion 224a' is subject to deformation. Never.

[0046] The outer projection 224b' includes a chamfer 246' that extends from the outer direction to the inner direction. The chamfer 246' of the side projection 224b' is formed so that the projection faces the bottom surface of the groove 136' of the neck screw 106'. The outer lug is designed to anticipate and prevent plastic deformation of the outer lug as it slides outward. It is being done.

[0047] Referring to FIG. 9C, the axial bore 122' of the intramedullary nail 102' is inserted into the housing 202'. Modified (with respect to the axial hole 122 of the intramedullary nail 102) to accommodate the three-leaf clover shape. It will be appreciated that variations may be made. For example, the axial bore 122' may be formed in the housing 202'. three longitudinal axes shaped and sized to receive respective lobes or apexes 222' of the The longitudinal slots 140 may also include longitudinal slots 140'. Each of the setscrews 140' is inserted into the nail 102' as the set screw assembly is introduced. may function as a track to stabilize the set screw assembly 200', and, after the set screw assembly is positioned within the axial bore 122', the set screw It may also function as a track to prevent unwanted post-operative rotation of the assembly. Furthermore, the axial holes 122' are each provided with a pair of adjacent longitudinal slots 140'. 126'。 In this way, the nail 102' includes an internal thread 126' disposed between the The alignment and engagement of the set screw assembly 200' may be improved. The modified fracture fixation device shown in 9H is an intramedullary intertrochanteric fracture fixation device 100. It can be used as described above and therefore will not be described in detail again here. .

[0048] 10A-10C illustrate an exemplary set screw assembly 20 according to another embodiment of the present disclosure. 1 is a plan view showing each of the set screw assemblies 200A to 200F. all features of set screw assembly 200 and / or set screw assembly 200'. The only difference is the shape of the housing. As used below with respect to 02F, the term "shape" refers to a shape perpendicular to the longitudinal axis. This refers to the cross-sectional shape of the housing when viewed from the outside.

[0049] Each set screw assembly 200A-200F preferably includes a respective housing 20 Different intramedullary nails with axial holes corresponding in shape to those of 2A to 2F (Fig. More specifically, each housing 202 A~202F is equal to the number of longitudinal slots in the axial hole of the corresponding intramedullary nail In this regard, each of the vertices is connected to a set screw adapter. The set screw assembly is inserted into the corresponding intramedullary nail to stabilize the set screw assembly. and after the set screw assembly is positioned in the axial hole of the intramedullary nail, Within each of the longitudinal slots, there is provided a stud, which prevents unwanted post-operative rotation of the assembly. Positioning can be performed.

[0050] For example, FIG. 10A shows a substantially oval shaped, more specifically, diametrically opposed, The housing 202A is oval shaped with two vertices 222A positioned at the center. 2 shows a set screw assembly 200A that is inserted into the corresponding intramedullary nail (not shown). The axial hole has two longitudinal slots located on opposite sides of the axial hole. It may be formed.

[0051] As shown in FIG. 10B, the housing 202B of the set screw assembly 200B The housing 202' is similar in shape to the housing 202' of the same assembly 200'. The housing 202B of the assembly 200B is substantially shaped like a three-leaf clover. 222B. However, the housing of the set screw assembly 200B The set screw assembly 200' has a slightly thicker sidewall 202B compared to the sidewall 216' of the set screw assembly 200'. Nevertheless, the corresponding intramedullary nail has an angular wall 216B around the axial hole. 9C, having three longitudinal slots spaced apart. It may also be formed in a systematic manner.

[0052] FIG. 10C illustrates a substantially triangular shaped housing 202 of set screw assembly 200. 2 shows a third exemplary housing 202C, which is similar to the housing 202A shown in FIG. 2C, the side wall 216C of the housing 202C is The set screw assembly 200 thus defines an arcuate notch between the set screw and the set screw. The intramedullary nail corresponding to C has three longitudinal studs angularly spaced around the axial hole. It may have an axial hole with a directional slot.

[0053] Now, referring to FIG. 10D, the shape of the housing 202D is substantially rectangular, More specifically, the side wall 216D of the housing 202D is square. An arcuate notch may be defined between each of the vertices 222D. The intramedullary nail corresponding to the screw assembly 200D has 90-degree intervals around the axial hole. This defines four longitudinal slots spaced apart.

[0054] As shown in FIG. 10E, the housing 202E of the set screw assembly 200E is The housing has a generally oval shape with two opposite vertices 222E. The side wall 216E of the housing 202E has two arcuate notches aligned along the minor axis of the housing. Thus, corresponding intramedullary nails may be positioned on opposite sides of the axial hole. The groove may define two longitudinal slots.

[0055] Referring to FIG. 10F, the housing 202F of the set screw assembly 200F includes four It has an apex 222F, a sidewall 216F that is thickened along its width and a thinned sidewall 216F that is thinned along its length. It should be understood that the sidewall 216F has a substantially rectangular shape. The thickness of the housing 202F may vary and / or vary along the width and / or length of the housing 202F. Therefore, the corresponding intramedullary nail preferably has a diameter of about 1 / 2 of the axial hole. It has four longitudinal slots spaced 90 degrees apart from each other.

[0056] Although FIGS. 10A-10F illustrate the housing as a particular shape, the housing It will be appreciated that the shapes may alternatively be formed as any polygonal shape. The number of vertices of the housing preferably corresponds to the longitudinal length formed in the axial hole of the corresponding intramedullary nail. The number of vertices in each housing is equal to the number of directional slots, but the number of vertices in each housing is It is understood that the number of longitudinal slots need not be equal to the number of longitudinal slots defined in the axial hole of the nail. It will be understood that one of the vertices of the housing is aligned with a single longitudinal slot of the nail. The set screw assembly is positioned within the longitudinal slots Although it is to a lesser extent than when the number of This will demonstrate the bone's ability to withstand rotational forces post-operatively.

[0057] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications can be made to the illustrative embodiments and other arrangements can be devised without departing from the spirit and scope of the present disclosure as defined by the appended claims. The technical concepts that can be understood from the above-described embodiments will be described below. [Aspect 1] 1. A set screw assembly for an intramedullary fracture fixation device, the set screw assembly having a longitudinal axis, the set screw comprising: a set screw including a body having external threads and a resilient member extending from the body, the resilient member having an uncompressed state and a compressed state; a housing including a sidewall defining a cavity for receiving the set screw; Including, a setscrew assembly, wherein the setscrew is fixed to the housing and rotatable relative to the housing about the longitudinal axis when the setscrew is at least partially disposed within the cavity and the resilient member is in the uncompressed state. [Aspect 2] The set screw assembly of aspect 1, wherein the housing and the set screw are cannulated such that the set screw assembly is configured to receive a guide wire. [Aspect 3] The set screw assembly of claim 1, wherein the elastic member includes a cantilevered flange having a first end attached to an end of the body and a second end positioned above the end of the body, and a gap is formed between the second end of the cantilevered flange and the end of the body. [Aspect 4] The set screw assembly of aspect 1, wherein the housing further includes a first end wall and a second end wall extending from the side wall transversely to the longitudinal axis, the first end wall and the second end wall being positioned at a distance from each other. [Aspect 5] A set screw assembly as described in aspect 4, wherein when the elastic member is in the uncompressed state, the set screw has a length along the longitudinal axis that is greater than the distance between the first end wall and the second end wall, and when the elastic member is in the compressed state, the length of the set screw in the direction along the longitudinal axis is less than or equal to the distance between the first end wall and the second end wall. [Aspect 6] 5. The set screw assembly of claim 4, wherein at least one of the first end wall and the second end wall includes a lip. [Aspect 7] 7. The set screw assembly of claim 6, wherein the set screw defines a stepped retention surface configured to engage the lip. [Aspect 8] 2. The set screw assembly of claim 1, wherein a portion of the external threads of the set screw extends outside the cavity when the set screw is secured to the housing. [Aspect 9] A set screw assembly as described in aspect 1, wherein the side wall of the housing defines a plurality of individual openings, and when the set screw is secured to the housing, a portion of the external thread of the set screw extends through each of the openings. [Aspect 10] 2. The set screw assembly of claim 1, wherein the lower portion of the housing includes at least one protrusion. [Aspect 11] A set screw assembly as described in aspect 10, wherein the at least one protrusion includes an inner protrusion having a first length and an outer protrusion having a second length longer than the first length. [Aspect 12] 12. The set screw assembly of claim 11, wherein the outer protrusion includes a chamfer extending from the outer direction to the inner direction. [Aspect 13] 11. The set screw assembly of claim 10, wherein the at least one protrusion includes an inner protrusion and an outer protrusion, each of which forms a curved shape when viewed in a medial-lateral direction. [Aspect 14] 14. The set screw assembly of claim 13, wherein the curved shape comprises a substantially parabola. [Aspect 15] 1. An intramedullary fracture fixation device comprising: an intramedullary nail having a proximal portion adjacent a proximal end and a distal portion adjacent a distal end, the proximal portion defining a beveled opening and an axial bore extending through the proximal end of the nail and into the beveled opening, the axial bore having a longitudinal axis, an internal thread, and at least one slot extending substantially parallel to the longitudinal axis; a neck screw configured to extend through the angled opening, the neck screw having an outer surface with grooves; a set screw assembly configured to be disposed within the axial bore of the intramedullary nail; Including, The set screw assembly a housing including an upper portion and a lower portion, the upper portion including a first end wall, a second end wall, and a side wall that collectively define a cavity; a set screw configured to be partially disposed within the cavity of the housing, the set screw having external threads; Including, When the set screw is partially positioned within the cavity of the housing and the set screw assembly is positioned within the axial hole of the intramedullary nail, the external threads of the set screw engage the internal threads of the axial hole, such that rotating the set screw rotates the set screw relative to the housing about the longitudinal axis and moves the set screw assembly along the longitudinal axis. [Aspect 16] A device as described in aspect 15, wherein the cross section of the upper portion of the housing is a polygon having at least one vertex positioned within the at least one slot to prevent rotation of the housing relative to the intramedullary nail when the set screw is rotated. [Aspect 17] Aspect 17. The device of aspect 16, wherein the polygon includes "n" vertices and the at least one slot includes a number of slots equal to "n." [Aspect 18] A device as described in aspect 15, wherein the cross-section of the upper portion of the housing is larger than the cross-section of the lower portion of the housing, thereby forming a shelf at the joint between the upper and lower portions of the housing. [Aspect 19] A device as described in aspect 18, wherein the proximal portion of the intramedullary nail includes a seat protruding inward into the axial bore for contacting the shelf portion of the housing to limit distal movement of the housing within the axial bore. [Aspect 20] A device as described in aspect 19, wherein the lower portion of the housing further includes a protrusion, and the lower portion of the housing includes a distal end that is inclined with respect to the longitudinal axis so that only the protrusion extends into the inclined opening when the shelf portion of the housing is in contact with the seat of the intramedullary nail. [Aspect 21] 16. The device of embodiment 15, wherein the setscrew comprises a resilient member having an uncompressed state and a compressed state. [Aspect 22] A device as described in aspect 21, wherein the set screw is sized so that insertion of the set screw into the cavity causes the elastic member to transition to the compressed state by contacting one of the first end wall or the second end wall. [Aspect 23] 1. An intramedullary fracture fixation device comprising: an intramedullary nail having a proximal portion adjacent a proximal end, the proximal portion defining a beveled opening and an axial bore extending through the proximal end of the nail and into the beveled opening, the axial bore having a longitudinal axis and an internal thread; a neck screw configured to extend through the angled opening; a set screw assembly pre-operatively assembled within the proximal portion of the intramedullary nail, the set screw assembly being cannulated to receive a guide wire; 1. An intramedullary fracture fixation device, comprising: [Aspect 24] Aspect 24. The device of aspect 23, further comprising a guide wire configured to extend through the set screw assembly and into the axial bore of the intramedullary nail. [Aspect 25] The set screw assembly a set screw including a body having an external thread; a housing including a sidewall partially surrounding the longitudinal axis and defining a cavity for receiving the set screw; a resilient member coupled to one of the body or the housing of the set screw, the resilient member having an uncompressed state and a compressed state; Including, A device as described in aspect 23, wherein when the set screw is at least partially positioned within the cavity and the elastic member is in an uncompressed state, the set screw is fixed to the housing and rotatable about the longitudinal axis relative to the housing.

Claims

1. 1. A set screw assembly for an intramedullary fracture fixation device, the set screw assembly having a longitudinal axis, the set screw comprising: a set screw having a body with external threads; a housing including a sidewall and first and second end walls extending from the sidewall transversely to the longitudinal axis, the sidewall partially surrounding the longitudinal axis, the first end wall, the second end wall and the sidewall in combination defining a cavity sized to receive the set screw, the first and second end walls having a cross section that is not perfectly circular; Including, the cavity is configured such that when the setscrew is inserted into and positioned within the cavity, the setscrew is fixed to the housing and is rotatable relative to the housing about the longitudinal axis; when the set screw is secured to the housing, a portion of the external thread of the set screw projects outside the cavity transverse to the longitudinal axis, and another portion of the external thread of the set screw is located inside the cavity; Set screw assembly.

2. The set screw assembly of claim 1, wherein when the set screw is fixed to the housing, the set screw assembly has an intubation point extending through the housing and the set screw along the longitudinal axis, and is configured to receive a guide wire through the intubation point.

3. 2. The set screw assembly of claim 1, wherein the side wall of the housing defines a plurality of separate openings, and when the set screw is secured to the housing, a portion of the external thread of the set screw extends through each of the openings.

4. The set screw assembly of claim 1 , wherein the lower portion of the housing includes at least one protrusion extending distally further from the distal end of the housing.

5. The set screw assembly of claim 4 , wherein the at least one protrusion includes an inner protrusion having a first length and an outer protrusion having a second length that is longer than the first length.

6. 1. An intramedullary fracture fixation device comprising: an intramedullary nail having a proximal portion adjacent a proximal end and a distal portion adjacent a distal end, the proximal portion defining a beveled opening and an axial bore extending through the proximal end of the nail and into the beveled opening, the axial bore having a longitudinal axis, an internal thread, and at least one slot extending in the direction of the longitudinal axis of the axial bore; a neck screw configured to extend through the angled opening, the neck screw having an outer surface with grooves; a set screw assembly having a longitudinal axis and configured to be disposed within the axial bore of the intramedullary nail; Including, The set screw assembly a set screw having a body with external threads; a housing including an upper portion and a lower portion, the upper portion including a sidewall and first and second end walls extending from the sidewall transversely to the longitudinal axis of the set screw assembly, the combination of the sidewall, the first end wall, and the second end wall defining a cavity sized to receive the set screw, the sidewall partially surrounding the longitudinal axis of the set screw assembly; Including, the cavity is configured such that when the setscrew is inserted into and positioned within the cavity, the setscrew is secured to the housing and is rotatable relative to the housing about the longitudinal axis of the setscrew assembly; when the set screw is secured to the housing, a portion of the external thread of the set screw projects outside the cavity transverse to the longitudinal axis of the set screw assembly and another portion of the external thread of the set screw is located within the cavity; When the set screw is partially positioned within the cavity of the housing and the set screw assembly is positioned within the axial hole of the intramedullary fracture fixation device, the external threads of the set screw engage the internal threads of the axial hole, such that rotating the set screw rotates the set screw relative to the housing about the longitudinal axis of the set screw assembly and moves the set screw assembly along the longitudinal axis of the axial hole.

7. The device described in claim 6, wherein the first end wall and the second end wall of the upper portion of the housing have a cross-section that is not perfectly circular, with at least one apex positioned within the at least one slot to prevent rotation of the housing relative to the intramedullary nail when the set screw is rotated.

8. 8. The device of claim 7, wherein the non-perfectly circular cross-section includes "n" vertices and the at least one slot includes a number of slots equal to "n".

9. A device as described in claim 6, wherein the cross-sections of the first end wall and the second end wall of the upper portion of the housing are larger than the cross-section of the lower portion of the housing, thereby forming a shelf portion at the joint between the upper and lower portions of the housing.

10. 10. The device of claim 9, wherein the proximal portion of the nail includes a seat that projects inwardly into the axial bore for contacting the ledge of the housing to limit distal movement of the housing within the axial bore.

11. 11. The device of claim 10, wherein the lower portion of the housing further includes a protrusion, the lower portion of the housing including a distal end that is angled relative to the longitudinal axis such that only the protrusion extends into the angled opening when the shelf of the housing contacts the seat of the intramedullary nail.

12. 1. An intramedullary fracture fixation device comprising: an intramedullary nail having a proximal portion adjacent a proximal end, the proximal portion defining a beveled opening and an axial bore extending through the proximal end of the nail and into the beveled opening, the axial bore having a longitudinal axis and an internal thread; a neck screw configured to extend through the angled opening; 10. The set screw assembly of claim 1 pre-operatively assembled within the proximal portion of the intramedullary nail, the set screw assembly having a cannulation point extending through the housing and the set screw along the longitudinal axis of the set screw assembly when the set screw is secured to the housing, the cannulation point configured to receive a guide wire through the cannulation point; 1. An intramedullary fracture fixation device, comprising:

13. The device of claim 12 , further comprising a guide wire configured to extend through the set screw assembly and into the axial bore of the intramedullary nail.

Images