US RE43482 E1
A bone stabilizing apparatus includes a stem member and an extension member, the stem member having a distal end for insertion within the intramedullary canal of a human humerus and the proximal end connected to the extension member. The extension member has radially directed threaded holes either pre-formed or created after the bone stabilizing apparatus is installed into the humerus. The threaded holes allow fixation of stabilizing screws with suture posts, or a washer structure to grip the surface of the bone and/or surrounding ligaments or muscle. A prosthetic or the natural humeral head can be attached to the extension member. In a preferred embodiment a guide structure directs the drill and stabilizing screws radially through the central axis of the extension member.
1. A bone stabilizing device, comprising:
a stem member, extending substantially along a first longitudinal axis, for insertion into a medullary bone cavity, said stem member having a distal end and a proximal end;
ana substantially cylindrical extension member positioned substantially outside of the medullary bone cavity, extending substantially along a second longitudinal axis, having a distal and a proximal end, said distal end connected to said proximal end of said stem member; and
means for securing a fractured metaphyseal or epiphyseal bone to said extension member comprising a securing member having a first end affixed intomechanically attached to the extension member and a second end spaced apart from said extension member, and means connected to said second end for pressing on a cortical surface of the bone to urge the bone against said extension member, wherein a third longitudinal axis of the securing member is unaligned with the second longitudinal axis of the extension member.
2. A bone stabilizing device according to
said means for securing boneplastic material further includes a threaded hole transversely disposed in and opening out of said extension member, and
said securing member includes an attachment screw having a threaded portion at its first end engaged with said threaded hole and having a screw head at its second end spaced apart from said extension member,
wherein a rotation of said threaded attachment screw urges said screw head against the bone material and thereby urges the bone material against the extension member.
3. A bone stabilizing device according to
wherein a rotation of said threaded attachment screw urges said washer against the bone material and thereby urges the bone against the extension member.
4. A bone stabilizing device according to
5. A bone stabilising device according to
a means for connecting the bone to the support plate through said plurality of passages.
6. A bone stabilizing device according to
said screws each having a first and second threaded portion, said first portion having a first thread pitch and said second portion having a second thread pitch greater than said first pitch, said screws being arranged such that said first portion is threaded into said bone and said second portion is threaded into said support plate,
whereby a rotation of said mounting screws urges said bone against said support plate.
7. A bone stabilizing device according to
an angled fixation bracket connected to said extension member, said angled fixation bracket having a support plate for supporting the bone;
a plurality of cannulated mounting screws each having a head on a first side of said support plate and a threaded portion extending into a bone on a second side of said support plate, said cannulated screws each having a through-bore; and
a suture thread passing through the through-bore of at least two of said cannulated screws and through said bone.
8. A bone stabilizing device according to
9. A bone stabilizing device according to
a first portion extending through a corresponding lateral clearance hole in said extension member;
a threaded portion for threaded engagement into said bone;
means for moving said rod axially through said lateral clearance hole; and
means for locking said rod to said extension member at a selectable axial position within said clearance hole.
10. A bone stabilizing device according to
a prosthetic humeral head;
positioning means for connecting said prosthetic humeral head to said extension member in a predetermined position humeral neck-shaft angle; and
means for locking prosthetic humeral head in said position.
11. A bone stabilizing device according to
12. A bone stabilizing device comprising:
a stem member, extending substantially along a first longitudinal axis, for insertion into a bone cavity;
ana substantially cylindrical extension member, connected to said stem member, said extension member having a plastic material,and extending substantially along a second longitudinal axis;
a prosthetic head having a mounting surface and a hemispherical shaped surface formed about a centerline; and
means for securing said prosthetic head to said extension member, said means comprising:
a support member connected to said extension member having a head support surface facing toward said mounting surface of said prosthetic head, said head support surface forming a predetermined angle with said extension member,
a hole formed in said support member and projecting into said head support surface toward said extension member, and
a pin connected to said mounting surface of said prosthetic head; and
means for securing a fractured metaphyseal bone to said extension member, said means for securing bone comprising:
an attachment screw having a threaded portion engaged with said extension member and having a screw head spaced apart from an outer surface of said extension member, wherein a rotation of said threaded attachment screw urges said screw head against the bone and thereby urges the bone against the extension member.
13. A bone stabilizing device comprising:
a stem member, extending substantially along a first longitudinal axis, for insertion into a bone cavity, said stem member having a distal end and a proximal end;
an extension member, extending substantially along a second longitudinal axis, having a distal and a proximal end;
a spacer bracket having a mounting flange with a hole formed therein and having a support face;
a threaded extension, formed on one of said proximal end of said stem member and said distal end of said extension member, said threaded extension passing through said hole in said mounting flange and threading into a threaded hole formed in the other of said proximal end of said stem member and said distal end of said extension member, so as to securely mount said mounting flange to said extension member and said stem member;
a prosthetic head having a substantially planar surface and having a hemispherical shaped surface formed about a centerline extending normal to said planar surface; and
means for securing said prosthetic head to said spacer bracket, said means comprising a tapered hole extending normal into a plane of the support face of said spacer bracket and a tapered pin connected to the planar surface of said prosthetic head.
14. A bone stabilizing device according to
means for securing a bone to said extension member, said means for securing said bone comprising:
a screw having a threaded portion engaged with said extension member and having a screw head spaced apart from an outer surface of said extension member, and
a washer disposed between said screw head and an outer surface of said extension member,
wherein a rotation of said threaded screw urges said washer against the bone and thereby urges the bone against the extension member.
15. A bone stabilizing device according to claim 1, wherein the securing member comprises a screw.
16. A bone stabilizing device according to claim 15, wherein the screw comprises a pressure type stabilizing screw, a suture type stabilizing screw, or an anchor with a threaded end and at least one flange at the second end.
17. A bone stabilizing device according to claim 15, wherein the means connected to said second end for pressing on a cortical surface of the bone comprises a head of said screw.
18. A bone stabilizing device according to claim 17, wherein said second end further comprises a washer.
19. A bone stabilizing device according to claim 18, wherein said washer comprises a claw washer.
20. A bone stabilizing device according to claim 19, wherein said claw washer comprises a slot.
21. A bone stabilizing device according to claim 1, wherein a distal tip of said first end of the securing member protrudes from the extension member.
22. A bone stabilizing device according to claim 1, wherein the first longitudinal axis forms an angle with the second longitudinal axis.
23. A bone stabilizing device according to claim 22, wherein the angle is less than 180 degrees.
24. A bone stabilizing device according to claim 1, wherein the securing member comprises at least one screw wherein the first end of the at least one screw is a threaded end, and wherein said means connected to said second end for pressing on a cortical surface of the bone to urge the bone against said extension member comprises at least one flange at the second end; and
wherein the bone stabilizing device further comprises a second means for securing the bone to said extension member.
25. A bone stabilizing device according to claim 1, wherein said bone is separated from an adjacent bone by a fracture line and said securing member crosses the fracture line to secure said bone to said extension member.
26. A bone stabilizing device according to claim 1, wherein said means for securing a bone to said extension member comprising more than one securing member.
1. Field of the Invention
This invention relates to an apparatus and method for the fixation of proximal humerus fractures in which one or more bone pieces must be aligned with the major portion of the bone. In proximal humerus fractures, displacing forces such as muscle connections acting on the fragments of the fracture frequently cause bone fragments to separate and pull away from the main part of the humerus. In alternative embodiments, this invention provides an apparatus and methods for internal fixation of fractured humerus bones, nonunions, and primary and metastatic tumors, in each case providing anatomic alignment to reduce impingement and promote healing.
2.Description of the Related Art
The conventional methods and apparatuses for treating proximal humerus fractures have respective shortcomings relating to effective treatment of many of the numerous categories of fractures. These categories correspond to proximal humerus fractures having predictable patterns. Specifically, displaced proximal humerus fractures are classified according to the displacement of humerus segments. Various apparatus and methods appear in the related art for treating proximal fractures of the humerus, including plates, screws, sutures and rods, but none of these solve all of the problems relating to fixation of these fractures.
One major problem in treating humerus fractures is the difficulty of finding adequate bone stock to secure the related art internal fixation means. The related art methods of fixation are therefore frequently difficult and unsuccessful, leading to possible loss of fixation, loss of fracture reduction, nonunion or malunion. Further, in many cases these methods do not allow early motion. Early motion is beneficial for cartilage nutrition and to prevent intraarticular adhesions and shoulder stiffness.
Some related art methods of fixation employ sutures attached to the rotator cuff musculature. Such a means of fixation does not provide the ease, anatomic alignment, and stability of the present invention, thereby also possibly leading to loss of fracture reduction or fixation.
A first conventional device, such as is shown in U.S. Pat. No. 4,919,670 to Dale et al., includes a stem portion for insertion into the intramedullary canal of the humerus and a head portion to replace the head of the humerus. This type of device is ineffective, however; at assisting in the fixation of bone fragments such as the lesser or greater tuberosity, or when the head of the humerus is to be saved. For example, the modular humeral prosthesis is designed to replace the natural humerus head and is not designed for a situation wherein the proximal humerus is fractured but the head is still attached or can be salvaged.
Another related art device is shown in U.S. Pat. No. 5,066,296 to Chapman et al describes an intermedullary rod used in the treatment of bone fractures. The Chapman apparatus utilizes an elongated body member inserted into a bone cavity and a tab member attached to the body member by a separate screw. The tab member has a transverse clearance aperture created prior to the tab member's attachment to the body member. A screw passes through the pre-formed clearance aperture, threads into a bone mass and pulls the bone against the tab member. The screw threads do not engage the tab member. Further, locking tabs on the tab member engage recesses on the body member, thereby eliminating any opportunity to rotate the tab member to selectively position the tab member aperture. This restriction limits the flexibility of this related art because, frequently, the pre-installed aperture cannot be optimally positioned. Further, this Chapman apparatus is applicable to diaphyseal fractures, i.e., fractures of the main bone shaft, and not metaphyseal or epiphyseal fractures such as proximal humerus fractures
Still another related art device is shown by U.S. Pat. No. 5,112,333 to Fixel and relates to fixation of femoral and tibial bone fractures. This type of intramedullary nail provides fixation of fractures of bone shafts, in which the intramedullary nail provides compressive force to the separated shaft portions. The Fixel intramedullary nail, however, is not addressed to, nor effective for, proximal humerus fractures, particularly the segmented proximal humerus fractures. The reason that Fixel, and similar, methods are not effective for such segmented fractures is that the intramedullary nail secures bone fragments using individual screws attached to bone and traversing through the nail to attach to bone as well. With segmented proximal humerus fractures, however, there is frequently little bone stock suitable for the screws to anchor to, and the bone that is available is frequently weak. Further, in one embodiment directed toward the fixation of distal femoral or tibial fractures, the Fixel method requires the individual screws to pass through the slotted tip of the nail, thereby limiting the possible directions of approach. This may serve for femoral and tibial fractures, but is unlikely to work for proximal humerus fractures with its accompanying complex anatomy and fracture patterns. The reason is that, for such complex anatomy and fractures, there is need for significant freedom in the placement of fixation screws to allow the surgeon to capture each of the individual fracture fragments and fixate them. The alternative means employed by the intramedullary nail to secure bone fragments involves a plate, and a plate is not appropriate for use in many proximal humerus fractures wherein the strength of surrounding soft tissue or musculature and not the bone itself is the best means available for stabilizing the fracture. Additionally, a plate is very prominent, and may cause impingement.
Another related art device is described, for example, within U.S. Pat. No. 5,201,733 to Etheredge, III, and relates to the fixation of a bone fracture in which fractured bone pieces are first positioned and held in place with preferably bioabsorble screws and pins. Metal reconstruction plates are then attached to the external surface of the bone with screws, clamps, or pins, without regard to the location of the underlying bioabsorbable screws and pins. This Etheredge and related methods therefore rely on the strength of the bone to hold the plate, and in many patients with proximal humerus fractures the bone quality is not adequate for such fixation, thereby incurring the risk of loss of fixation of the fracture. Further, this method is generally ineffective in a proximal humerus fracture wherein multiple bone fragments are separated from the humerus. This is because a straight plate is not appropriate on a rounded humerus fragment, such as a head. Therefore, this Etheredge and related plate methods are best applicable for diaphyseal fractures only, not the metaphysical and epiphyseal types such as those that occur with proximal humerus fractures.
Another shortcoming of plate methods is that the installation of a plate involves stripping of the soft tissues from the bone. This is necessary for the plate to lie flat on the bone. The stripping, however, inhibits subsequent blood supply to the fragments because the soft tissue attachments provide that blood supply. This blood supply reduction can retard healing of the bone. Therefore, any fixation applied to the superficial surface of the bone risks damage to the blood supply of the bone fragments.
It is therefore an object of this invention to overcome the above-identified problems in the related art, and to provide an apparatus and methods for precise and stable fixation of proximal humerus fractures to promote correct anatomic bone position with reduced chance of bone fixation failure or later impingement.
It is a further object of this invention to provide a method and apparatus for fixation of a proximal humerus fracture that allows motion of the humerus early in a patient's recovery.
Another object of this invention is to provide a method of stabilizing a proximal humerus fracture using inventive screw means to stabilize the fracture.
A further object of this invention is to provide an apparatus that can be adapted for use with all categories of proximal humerus fractures.
A still further object of this invention is to provide for optional replacement of the proximal humeral head.
Another object of this invention is to provide a method and apparatus for stabilizing and repairing intraosseous cavities, voids, or pathologic fractures from primary and metastatic tumors.
A still further object of this invention is to provide a method and apparatus to stabilize and treat non-union and malunion of fractures.
A further object of this invention is to provide an improved method and apparatus for fixture and repair of humeral shaft fractures.
The present invention is directed to an apparatus for and method of treating proximal humerus fractures, humeral shaft fractures, nonunions and malunions of the proximal humerus or humerus shaft, and cavities resulting from primary and metastatic tumors. This invention also allows for reattachment or replacement of the humeral head. The method allows for internal fixation of fractures of substantially all known patterns.
In a general embodiment, the intramedullary rod of the present invention comprises a stem member and an extension member. The apparatus may be a one-piece structure of one material, or may be either a permanent or removable assembly of a stem member and an extension member.
The stem member is elongated, substantially cylindrical, and incorporates a plurality of transverse passages, either preformed or fabricated at time of insertion. Each transverse passage extends transversely through the longitudinal axis of the stem portion and is shaped for receiving stabilizing screws or equivalent structures for securing the intramedullary rod to the humerus. The proximal end of the stem member for this illustrated embodiment is slightly angled, relative to the central longitudinal axis of the major portion of the stem. Alternatively, the extension and stem member can be collinear.
In a first embodiment the extension member connects to the proximal end of the stem member, by threads or equivalent attachment means.
The extension member is formed of a material suitable for being drilled and, if self-threading screws are not used, tapped. The extension member is described further below as substantially cylindrical, but it can have a square, rectangular, triangular, or other shape in cross-section. Stabilizing screws, generally self-threading, are removably screwed into the intramedullary rod to apply fixation force to the fractured bone or associated soft tissue, for the purpose of stabilizing the humerus fracture and allowing it to heal. The fixation force is exerted by the stabilizing screw head, preferably through a force-distributing member, such as, for example, a claw washer, or by sutures looped through securing members formed on the stabilizing screws. This invention thereby provides a novel method of distributing the fixation force over a larger area of surrounding bone and soft tissue.
Another embodiment includes structure for fixing the natural humerus head to the extension member at a proper angle.
Still another embodiment includes a prosthetic humerus head with structure for attaching the prosthetic to the extension member at a proper angle.
A still further method and apparatus includes passages formed in the extension member through which a biocomposable glue or cement is injected, thereby filling intraosseous cavities between the extension member and surrounding bone material.
A further embodiment includes fixation devices inserted into the extension member and secured by a filling type cement into cavities in the proximal humerus.
As a still further embodiment, the present inventive method includes the steps of inserting the stem portion of the intramedullary rod into the medullary canal of the humerus; attaching the extension member to the stem portion; drilling and, optionally, tapping passages into the extension member; affixing a screw into such passages to provide means of gripping and stabilizing the fractured bone and surrounding tissue to the intramedullary rod, thereby realigning the fractured ends into anatomic position.
A further method includes an adjustable screw alignment guide which is removably and temporarily attached to the extension member to provide a guide for accurate and on-center drilling of the extension member.
FIG. 33A depicts a removable screw alignment guide, shown inserted in the extension member; FIG. 3B shows a screw guide sleeve usable with the screw alignment guide of FIG. 3A;
The structure and method of the present invention is described in the context of treating proximal fractures of the humerus. The present invention is, however, not limited to treating proximal humerus fractures, but may be used for treating other fractures of the humerus as well as fractures of other bones. It may also be used to treat nonunions, malunions, bone tumors, and cavitary lesions.
The first embodiment of the present invention will be described in reference to
Referring again to
Passages 10 and 12 are preferably pre-formed when stem member 1 is composed of metal, but may be formed at any point along the stem member 1 at the time of the intramedullary rod's installation when stem member 1 is composed of plastic, composite, or other drillable and tappable material.
Through-bore 4 allows insertion of stem member 1 into the intramedullary channel of the humerus about a guidewire (not shown). Installation of the guidewire is well known in the art and shown, for example, in “Humeral Interlocking Nail System,” an article in the booklet Surgical Technique by Russell-Taylor, incorporated herein by reference.
As shown in
Stem member 1 can be selected in length to extend any length down the intramedullary canal of the humerus. Extension member 2 has, for the depicted example of this embodiment, threads 16 on its distal end to fit the proximal end 14 of stem member 1. However, extension member 2 may be attached to stem member 1 by alternate means, such as a Morse taper pin (not shown) at the distal end 8 of extension member 2 and corresponding tapered hole (not shown) at the proximal end 8 of the stem member 1, or adhesive (not shown). Alternatively, one or more screws (not shown) could removably connect through both stem member 1 and extension member 2 after the distal end of extension member 2 is inserted into proximal end 8 of stem member 1. In another alternative means of attachment (not shown) extension member 2 is molded or otherwise attached, at its distal end to a metal adapter (not shown) which is threaded to removably attach to proximal end 8 of stem member 1. Further, stem member 1 and extension member 2 can be formed of a single unit, using material that is both drillable for extension member 2 and sufficiently strong for stem member 1.
The extension member 2 includes one or more substantially transverse passages 20 which are drilled, or otherwise created through extension member 2 at the time of fixation of the humerus fracture. Passages 20 are threaded and dimensioned so as to removably engage pressure-type or suture type stabilizing screws numbered as 22 and 24. The passages 20 are threaded, for example, by tapping or by using self-tapping screws for 22 and 24.
Pressure-type stabilizing screws 22, shown in detail in
The suture-type stabilizing screw 24, shown in more detail in
In one alternative embodiment (not shown) extension member 2 is encased in a ribbed metal cover. In yet another embodiment (not shown) the extension member comprises a drillable plastic or bioabsorbable material having internal longitudinal wires or ribs (not shown) of metal or carbon fiber or other reinforcing material disposed within for added strength. The wires (not shown) would be suitably thin, so as not to interfere with drilling of the passages 20.
A person of ordinary skill in the art will appreciate that extension member 2 is envisioned in various dimensions as needed for particular applications.
Installation of the modular intermedullary rod preferably employs the screw alignment guide 34 shown in FIG. 33A. The screw alignment guide 34, as described below, attaches to the extension member via removable pivot pin 36, and adjusts along three axises for positioning, aligning, and centering passages 20 created in extension member 2. Pivot pin 36 is elongated and cylindrical, and removably connects to proximal end 38 of extension member 2 via, for example, threaded hollow channel 40. Alternate means for a removable securing of the pivot pin 36 to the extension member 2 are readily apparent to one of ordinary skill. For example, the pivot pin could slide into an equivalent of the threaded channel 40 and be secured by a lock screw (not shown) entering through a tapped hole (not shown) transverse to the extension member 2.
As shown in FIG. 3B3A, screw alignment guide 34 thus rotates about the common axis of pivot pin 36 and extension member 2. The pivot pin 36 employs locking nut 42 to secure it to the extension member 2. The pivot pin 36 passes through the pivot hole 44 in the pivot arm 46 of the screw alignment guide 34, the pivot having sufficient clearance to allow linear motion of the pivot arm 46 along the axis A of the extension member and rotational motion around said axis B. Thumb screw 48, or an equivalent locking mechanism, reversibly locks the pivot arm 46 in a selected position.
Screw alignment guide 34 also includes an angle mechanism 50 for supporting at an adjustable angle, a guide holder 52. The guide holder 52 pivots about a pin 54, within plane C and allows adjustment of screw position within that plane while assuring intersection of the screw with the extension member. The angle mechanism 50 is locked in position by a thumb screw 56 or equivalent. The guide holder 52 holds, via a close fitting slip means, a drill sleeve 58. The guide holder 52 and drill sleeve 58 guide the drill bit (not shown) to ensure that the passage 20 is formed through the central axis A of extension member 2. The drill sleeve 58 is shown as a two-piece structure but a single piece sleeve (not shown) could be substituted.
It can be seen that screw alignment guide 34 allows for sufficient adjustment in orienting the guide holder 52 to allow passages to be quickly drilled, tapped, reamed, or otherwise created in any necessary orientation through extension member 2, regardless of visual obstruction from adjacent tissue and matter.
Optionally, after the passages 20 have been formed the drill sleeve 58 is removed and, to better ensure proper orientation of stabilizing screws 22 and/or 24 to extension member 2, a screw guide sleeve 59 is inserted into the guide holder 52 in place of the drill sleeve 58. The screw guide sleeve 59 is a two-piece structure comprising a body 59a and a head 59b, as shown in FIG. 3B. The bore (not numbered) of the assembled and inserted sleeve 59 is slightly larger than the diameter of the screw head 22a shown in
One ordinarily skilled in the art will appreciate that use of this method and apparatus allows easy location of the target passage 20 for a stabilizing screw 22 or 24, even when passage 20 is not visible.
As described above, the present embodiment, as shown in
With reference to
Additionally, the juncture of prongs 26b to portion 26a of claw washer 26 may be curved. Further, the number of prongs 26b is not limited or restricted by the number illustrated in
Alternatively, (not shown) a force-distributing washer (not shown) without prongs but having a suitably wide force distributing area could be used. However, by gripping surrounding bone and soft tissue, claw washer 26 allows fracture fragments to be correctly and anatomically aligned during fixation and held there firmly.
In addition, one of skill in the art may use this invention as shown in
Still further, one of skill in the art may use the slotted claw washer shown in
It will be understood by one skilled in the art that the size and orientation of claw washer 26 and stabilizing screw 22 must be such as to avoid impingement with the acromion process, such that early and continued motion is possible after fixation of the fracture.
As described above, claw washer 26 and sutures (not numbered) threaded through the eyelet 24c of stabilizing screw 24 provide alternative methods of fracture fixation. Because stabilizing screws 22 and 24 are securely fastened to the extension member 2, it will be obvious to one skilled in the art that stabilizing screws 22 and 24 need not be affixed directly to bone, which is often a weak point for a fixture attachment. Of course, for additional stabilization, the length of screws 22 and 24 can be chosen to pass through the bone on one side of the extension member 2, thread through the extension member 2 and then pass back into the bone on the other side of the extension member 2.
Stabilizing screws 22 and 24 and claw washer 26 can be made of metal, plastic, composite, bioabsorbable (such as polyglycolic acid), or other suitable material. Further, claw washer 26 may be used with a pressure-type stabilizing screw 22, as shown in
As a further embodiment of the present invention, after fixation of the humeral fracture, a threaded plug or cap (not shown) is threaded into the threaded hole 40 so as to cover the proximal end of extension member 2. The cap prevents bony and soft tissue ingrowth into the hole 40 of the extension member 2 and will facilitate later removal of the rod if needed.
Another embodiment, illustrated in
Preferably, angled fixation bracket 64 is composed of a bioresorbable, possibly water insoluble non-toxic, material selected from the group of polymers consisting of polyglycolic acid, copolymers of glycolic acid and lactic acid, copolymers of lactic acid and aminocaproic acid, lactide polymers, homopolymers of lactic acid, polydesoxazon, polyhydroxybutric acid, copolymers of hydroxybutyric and hydroxyvaleric acid, polyesters of succinic acid and cross-linked hyaluronic acid. However, other suitable materials include plastic, composite (such as polyethylene reinforced with carbon fibers or metallic filaments), or metal.
It will be understood by one skilled in the art that a small surface area for base plate 72 is preferred, to prevent obstruction of the healing ingrowth of bone.
As is best seen in
A variation (not shown) of the above embodiment uses an angle fixation bracket that is unitary, either made as a one piece unit or permanently attached, with the extension member 2. This would provide simpler structure with installation flexibility adequate for some instances.
In another embodiment, illustrated in lateral view in
In still another embodiment, shown in
Still another embodiment, shown in
Alternatively, instead of cannulated screws 106, hollow pegs (not shown), either with or without suture tie bars (not shown) could be pre-formed on or formed integral to, or pre-pressed into, or fixed on the angled fixation bracket plate 109, protruding at the location were clearance holes 88 or suture holes 70 are shown. Sutures would pass through these pegs (not shown) and allow ready attachment of the anatomic head fragment 66.
Attachment by sutures or bioabsorbable screws, as described above, facilitates later removal of the angled fixation bracket, and the entire intramedullary rod if necessary, such as during an arthroplasty if humeral head replacement becomes necessary later.
As shown at
For the embodiments of
Another embodiment of the present invention will be described in reference to
Still another embodiment of the present invention is depicted in cross-sectional view in
The extension member 156 may be formed of a drillable material, such as extension member 2 of the
As shown in
The humeral length problem can be easily solved with this embodiment. Specifically, by having a set of heads 148 at the time of installation with numerical values of D over a selected range, including a no-offset zero where the pin 152 is on the centerline, adjustment of the length LE can be effected, and hence the correct humeral length established. This addresses a factor in prosthetic replacement of the proximal humerus in that for related fractures, the surgical neck fracture is often lower than the cut made when placing the prosthesis in a nonfractured humerus. The result of the surgical neck fracture being lower than the cut is that when one completely inserts, or “sinks,” the prosthesis to the level of the fracture it may be too distal in the humerus, thereby causing the length problem. However, by having a range of heads 148 on hand at the time of installation, with varying offsets D, the method and apparatus of this embodiment solves this length problem.
Further to this embodiment is that the length ML of the Morse pin 152 can be selected to compensate for the component of the offset D that laterally offsets the humeral head. Referring to
Optional to the
A variation of the above embodiment is shown in the cross-sectional view of
The prosthetic head 158 and spacer bracket 160 of this embodiment are preferably formed of a chromium-cobalt alloy or similar biocompatible alloy. The extension member 166 may be formed of metal or, as shown in the example of
It will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent. For example, the intramedullary rod apparatus in