DEVICE FOR ANIMAL TIBIAL OSTEOTOMY STABILIZATION
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Serial No. 63/621,577, filed January 16, 2024, and entitled “DEVICE FOR ANIMAL TIBIAL OSTEOTOMY STABILIZATION,” which is hereby incorporated by reference herein in its entirety.
BACKGROUND
Field
[0002] The present disclosure relates to tibial plateau leveling osteotomy (TPLO) bone plates and procedures for canines and other four-legged animals.
Related Art
[0003] Tibial plateau leveling osteotomies, in addition to other tibial osteotomies, are commonly performed in dogs, and occasionally in other animal species such as cats, to address rupture of the cranial cruciate ligament. Tibial plateau leveling osteotomy plates used in canines typically have an asymmetric shape with a relatively shorter upper portion and an elongated lower portion.
BRIEF SUMMARY
[0004] According to an aspect of the present technology, a tibial plateau leveling osteotomy (TPLO) bone plate is provided. The TPLO bone plate comprises a first portion configured to be fixed to a lower portion of a tibia below an osteotomy. The first portion has a length between 7 mm and 4 cm and has a first row of multiple screw holes configured adjacent to the osteotomy. The TPLO bone plate further comprises a second portion configured to be fixed to an upper portion of the tibia above the osteotomy.
[0005] According to an aspect of the present technology, a tibial plateau leveling osteotomy (TPLO) bone plate is provided, comprising an upper portion configured to be fixed to an upper portion of a tibia above an osteotomy, and means for securing a lower portion of the tibia below the osteotomy without interfering with a semitendinosus tendon.
[0006] According to an aspect of the present technology, a method of performing a tibial plateau leveling osteotomy (TPLO) on a patient is provided. The patient may be a canine or other four-legged animal. The method comprises creating an incision in the patient adjacent a tibia of the patient, cutting the tibia to form an upper portion and lower portion of the tibia separated by an osteotomy, and fixing a TPLO bone plate to the tibia to stabilize the osteotomy, without incising a semitendinosus tendon on a medial tibia and without positioning the TPLO bone plate underneath and distal to the semitendinosus tendon.
BRIEF DESCRIPTION OF DRAWINGS
[0007] Various aspects and embodiments will be described with reference to the following exemplary and non-limiting figures. It should be appreciated that the figures are not necessarily drawn to scale. Items appearing in multiple figures are indicated by the same or a similar reference number in all the figures in which they appear.
[0008] FIG. 1 illustrates a tibial plateau leveling osteotomy (TPLO) stabilized with a 6- hole TPLO bone plate that includes only round holes both proximal and distal to the osteotomy.
[0009] FIG. 2 illustrates a TPLO stabilized with a 6-hole TPLO bone plate with two oval holes immediately distal to the osteotomy to allow compression of the osteotomy.
[0010] FIG. 3 illustrates a TPLO stabilized with a 6-hole TPLO bone plate with two snowman- shaped holes immediately distal to the osteotomy to allow freedom in where screws are placed within those holes (e.g., placed at the upper versus lower portion of the snow-man shaped hole).
[0011] FIG. 4 illustrates a TPLO stabilized with an 8-hole TPLO bone plate that includes only round holes both proximal and distal to the osteotomy.
[0012] FIG. 5 illustrates a TPLO stabilized with an 8-hole TPLO bone plate with two oval holes immediately distal to the osteotomy to allow compression of the osteotomy.
[0013] FIG. 6 illustrates a TPLO stabilized with an 8-hole TPLO bone plate with two snowman- shaped holes immediately distal to the osteotomy to allow freedom in where screws are placed within those holes (e.g., placed at the upper versus lower portion of the snowmanshaped hole). [0014] FIG. 7 illustrates a TPLO stabilized with an 8-hole TPLO bone plate that includes only round holes both proximal and distal to the osteotomy but with a different shape than the TPLO bone plate shown in FIG. 4.
[0015] FIG. 8 illustrates a TPLO stabilized with an 8-hole TPLO bone plate that includes a singular fenestration 809 in the bone plate to facilitate visualization of the central portion of the osteotomy during surgery and radiographically.
[0016] FIG. 9 illustrates a TPLO stabilized with an 8-hole TPLO bone plate that includes three small fenestration windows in the bone plate to facilitate visualization of the central portion of the osteotomy during surgery and radiographically.
[0017] FIG. 10 illustrates a TPLO stabilized with a 6-hole TPLO bone plate as viewed in the frontal plane (z.e., from cranial to caudal), showing the contour of the TPLO bone plate.
[0018] FIG. 11 illustrates a TPLO stabilized with a TPLO bone plate as viewed in the frontal plane and showing that different types of screws can be used with the TPLO bone plate and that screw trajectories may vary with different embodiments of the device.
[0019] FIG. 12 illustrates a TPLO stabilized with a TPLO bone plate as viewed in the frontal plane.
[0020] FIG. 13 illustrates a perspective view of one embodiment of a TPLO bone plate with 6 round holes to accommodate locking (angle stable) screws.
[0021] FIG. 14 illustrates a perspective view of an alternative embodiment of a TPLO bone plate with 6 holes, two of which are oval holes for compression of the osteotomy.
DETAILED DESCRIPTION
[0022] Aspects of the present technology relate to plates for tibial plateau leveling osteotomy (TPLO). However, these plates can be used in alternative embodiments for fracture repairs of numerous bones including the tibia, femur, ilium, humerus, and radius and ulna. The inventor(s) has recognized that conventional TPLO bone plates are problematic in various applications to stabilize the tibia following a TPLO, including canine applications. Conventional TPLO bone plates include an elongated segment which is to be positioned along the medial portion of the tibia. This elongated segment typically includes holes arranged in a substantially linear fashion to accommodate a single column of screws, or slightly staggered linear array of screws, arranged substantially linearly along the tibia. The length of the plate, however, forces the surgeon to choose between A) incising the semitendinosus tendon or B) positioning the elongated segment of the plate underneath the semitendinosus tendon during installation of the plate with required dissection distal to the semitendinosus tendon for placement of the most distal screws in the plate. Neither option is optimal. Incising the semitendinosus tendon damages the tendon, which can result in unnecessary morbidity. Positioning the elongated segment of the plate underneath the semitendinosus tendon, with required dissection of tissue distal to the semitendinosus tendon, is more cumbersome, requires dissection and time, more soft tissue trauma, and can also produce negative post-surgical outcomes. Moreover, the length of the elongated portion of such plates is such that the elongated portion often extends to where the tibia narrows, increasing the difficulty of centering the elongated portion over the tibia. The inventor has recognized that such risks and negative outcomes may be avoided with an alternative plate structure.
[0023] Aspects of the present disclosure provide shorter TPLO bone plates that afford sufficient stability of the osteotomy while avoiding interference with the semitendinosus tendon and therefore decreasing the length of the incision, and extent of soft tissue surgical dissection needed to apply them, simplifying the surgical procedure, and improving patient outcomes.
[0024] Aspects of the present disclosure provide a TPLO bone plate for use in canines and felines, with potential broader applicability to other four-legged animals. The plate is configured to accommodate, on both sides of the osteotomy, multiple screws close to the osteotomy. The plate may accommodate at least three screws on either side of the osteotomy in some embodiments. The plate may be configured to not extend more than 4 cm distal to the most distal screw (with regard to the length of the bone plate) of the proximal segment. In some embodiments, the plate may be substantially symmetrical along a mid-line of the plate configured to be aligned with the osteotomy.
[0025] FIG. 1 illustrates a TPLO stabilized with a 6-hole TPLO bone plate that includes only round holes both proximal and distal to the osteotomy. The bone plate 102 includes a first portion 103a, which may be a distal portion, and a second portion 103b, which may be a proximal portion, configured to be positioned on opposite sides of the osteotomy 105. The bone plate 102 may be fixed to the tibial lower portion 104 and tibial upper portion 106. The tibial upper portion 106 is adjacent the femur 108, with the patella 110 positioned near the femur 108.
[0026] As shown in FIG. 1, the bone plate 102 includes multiple holes positioned within the bone plate to be close to the osteotomy 105 when the bone plate 102 is fixed to the tibial lower portion 104 and tibial upper portion 106. In this example, holes 107a, 107b, 107d, and 107e are all close to the osteotomy 105. Notably, the positioning of holes 107a and 107b results in them in combination being closer to the osteotomy 105 than would be possible if the first portion 103a of the bone plate 102 accommodated just a single role of screw holes along the length of the tibial lower portion 104. The holes 107c and 107f are positioned within the bone plate 102 such that they are farther from the osteotomy 105 than the other four holes, but still relatively close to the osteotomy 105.
[0027] The positioning of multiple holes on either side of the osteotomy and in close proximity to the osteotomy provides secure fixation of the bone plate 102 to the tibial lower portion 104 and tibial upper portion 106.
[0028] As described above, the bone plate 102 may have a length which avoids the drawbacks of either needing to incise the semitendinosus tendon or positioning the bone plate underneath the semitendinosus tendon during implantation. The first portion 103a of the bone plate 102 has a length LI and the second portion 103b has a length L2. The length LI may be sufficiently small to avoid the first portion 103a interfering with the semitendinosus tendon. And, in general the length LI will be approximately the same as the length L2. This contrasts with conventional TPLO bone plates which have an elongated lower portion and in which the lower portion is typically two times (or maybe more) longer than the upper portion (i.e., LI is often at least twice the length of L2 in conventional TPLO bone plates). The length LI in the described bone plate may be between 7 mm in plates for smaller animals and a maximum of 4 cm, typically for application in larger dogs, in some embodiments. Thus, the length LI may be between 7 mm and 4 cm in some embodiments, including any value within that range. The length LI may be selected such that the first portion 103a does not require incision of the semitendinosus tendon, or dissection distal to the semitendinosus tendon, for implantation including placement of a screw in hole 107c. The length LI may be selected to be a value allowing the first portion 103a to accommodate two rows of screws (2 to 5 screws maximum). For example, as shown in FIG. 1, the first portion 103a includes holes 107a and 107b which are approximately an equal distance from the osteotomy and a hole 107c which is further from the osteotomy than those two holes. The holes 107a and 107b may be considered to constitute a first row and the hole 107c a second row.
[0029] The length L2 of the second portion 103b of the bone plate may be selected to be a value such that the TPLO bone plate 102 does not extend above the tibial upper portion 106. In some embodiments, the length L2 may be between 7 mm cm and 3.5 cm, including any value within that range. Other lengths are possible.
[0030] As shown in FIG. 1, the TPLO bone plate 102 is approximately symmetrical about the osteotomy 105 with regard to length of the bone plate. The lengths LI and L2 are substantially equal in some embodiments. In some embodiments, the lengths LI and L2 are within 25% of each other. Also, it should be appreciated that due to the lengths LI and L2, when the TPLO bone plate 102 is positioned to fix the tibia after the osteotomy has been made, the extent of the maximum distance the TPLO bone plate may extend away from the osteotomy is given by the lengths LI and L2 and any distance between LI and L2, and therefore may be between 7 mm and 4 cm (including any value in that range) in some embodiments, and in some embodiments greater than 4 cm.
[0031] As shown, the shape of the first portion 103a and the second portion 103b may be rounded and/or have rounded corners. For example, the first portion 103a and/or the second portion 103b may be approximately a rounded rectangle, or other rounded polygon. The first portion 103a and second portion 103b lack an elongated shape. In some embodiments, the first portion 103a and/or second portion 103b may have a shape which expands (in a direction perpendicular to LI and L2) moving away from the osteotomy 105. That is, the first portion 103a and/or second portion 103b may be narrower (in a direction perpendicular to LI and L2) near the osteotomy than further away from the osteotomy. In some embodiments, the first portion 103a and/or second portion 103b may be bulbus. As can also be seen in FIGs. 2-8 and 13-14, described further below, other embodiments of the present disclosure provide TPLO bone plates with first and second portions which may have any of those types of shapes listed here.
[0032] FIG. 2 illustrates a TPLO stabilized with a 6-hole TPLO bone plate with two oval holes immediately distal to the osteotomy to allow compression of the osteotomy. Reference numbers appearing in FIG. 1 are not described in detail again here.
[0033] The TPLO bone plate 202 includes a first portion 203a and second portion 203b. The first portion includes holes 207a, 207b, and 107c. The holes 207a and 207b are oval holes, or compression holes, which may accommodate screws providing compression of the osteotomy 105. Otherwise, the TPLO bone plate 202 may be substantially the same as TPLO bone plate 102 of FIG. 1. For example, the first portion 203a may be similarly shaped to first portion 103a and may have the same lengths as those described for LI. The second portion 203b may be substantially identical to the second portion 103b and may have the same lengths as those described for L2.
[0034] FIG. 3 illustrates a TPLO stabilized with a 6-hole TPLO bone plate with two snowman- shaped holes immediately distal to the osteotomy to allow freedom in where screws are placed within those holes (e.g., placed at the upper versus lower portion of the snow-man shaped hole). These snowman- shaped holes may also facilitate compression of the osteotomy. The TPLO bone plate 302 includes a first portion 303a and second portion 303b. The first portion 303a includes holes 307a, 307b, and 107c. The holes 307a and 307b are snowmanshaped holes, permitting placement of screws at various locations within those holes. Otherwise, the TPLO bone plate 302 may be substantially the same as TPLO bone plate 102 of FIG. 1. For example, the first portion 303a may be similarly shaped to first portion 103a and may have the same lengths as those described for LI. The second portion 303b may be substantially identical to the second portion 103b and may have the same lengths as those described for L2. The shapes of the first portion 303a and 303b may be any of those described previously, for example in connection with FIG. 1.
[0035] FIG. 4 illustrates a TPLO stabilized with an 8-hole TPLO bone plate with four holes both proximal to and distal to the osteotomy. The TPLO bone plate 402 includes a first portion 403a and second portion 403b. The first portion includes holes 107a, 107b, 107c, and 407g. All four of these holes are round holes. It can be seen in the figure that holes 107a and 107b are in a first row and holes 107c and 407g are in a second row, meaning that the first portion 403a comprises multiple rows of screw holes with each of the two rows comprising multiple screw holes. The second portion 403b includes holes 107d, 107e, 107f, and 407h. The first portion 403a may have the same lengths as those described for LI (or slightly longer than LI). The second portion 403b may have the same lengths as those described for L2 (or slightly longer than L2). The shapes of the first portion 403a and 403b may be any of those described previously, for example in connection with FIG. 1. For example, the first portion 403a and second portion 403b may have rounded corners. Both portions lack an elongated shape.
[0036] FIG. 5 illustrates a TPLO stabilized with an 8-hole TPLO bone plate with two oval holes immediately distal to the osteotomy (507a and 507b) to allow compression of the osteotomy. The TPLO bone plate 502 has a first portion 503a and second portion 503b which are substantially similar to TPLO bone plate 402 with first portion 403a and second portion 403b, including in shape and length. The two oval holes 507a and 507b facilitate compression of the osteotomy 105. As shown, the two oval holes 507a and 507b may be in a first row of screw holes in the first portion 503a, with holes 107c and 407g representing a second row of screw holes in the first portion 503a. The first portion 503a and second portion 503b lack an elongated shape.
[0037] FIG. 6 illustrates a TPLO stabilized with an 8-hole TPLO bone plate. The bone plate 602 has a first portion 603a and second portion 603b. The holes 407g and 107c in the first portion 603a are round and substantially similar to those described for TPLO bone plates 502 and 402 in FIG 5 and FIG 4, respectively. The holes 307a and 307b in the first portion 603a are ‘snow-man shaped’ and substantially similar to those in TPLO bone plate 302 in FIG 3. These holes allow for flexibility /freedom in placing the screws in either the upper or lower portion of the snow-man shaped hole and also allow compression of the osteotomy. The holes in the second portion 603b are round and substantially similar to those previously described for TPLO bone plate 402 in FIG. 4 (i.e., holes 107d, 107e, 107f, 407h). Holes 608a and 608b are small, round holes that can accommodate temporary holding wires that temporarily secure the plate to the tibia upper portion 106 and tibial lower portion 104 during a TPLO procedure until the TPLO bone plate 602 is firmly secured to the tibia with screws. The snowman- shaped holes 307a and 307b also facilitate compression of the osteotomy 105.
[0038] FIG. 7 illustrates a TPLO stabilized with an 8-hole TPLO bone plate with different shape than TPLO bone plate 402 shown in FIG. 4. Otherwise, all screw holes (107a, 107b, 107c, 107d, 107e, 107f, 407g, 407h) and temporary wire holes 608a and 608b are substantially similar to those shown in FIG. 4 and FIG. 6 respectively. The TPLO bone plate 702 has a first portion 703a and a second portion 703b. As illustrated, each of the first portion 703a and second portion 703b has a shape with rounded comers. The TPLO bone plate 702 is narrower near the osteotomy and expands outward further from the osteotomy. The first portion 703a may be a rounded rectangle in some embodiments. More generally, the first portion 703a and/or second portion 703b may have the shapes described previously in connection with FIG. 1. The first portion 703a and second portion 703b may have lengths given by LI and L2, the values of which have been described previously herein.
[0039] FIG. 8 illustrates a TPLO stabilized with an 8-hole TPLO bone plate that is substantially similar to TPLO bone plate 402 shown in FIG. 4. The TPLO bone plate 802 includes a first portion 803a and second portion 803b. All screw holes (107a, 107b, 107c, 107d, 107e, 107f, 407g, 407h) and temporary wire holes 608a and 608b are substantially similar to those shown in FIG. 4 and FIG. 6, respectively. FIG. 8 also includes a singular fenestration window 809 in the TPLO bone plate 802. This fenestration window 809 enables the surgeon performing a TPLO procedure to see the osteotomy (e.g., osteotomy 105) at the location of the fenestration window 809 during the surgery and enables radiographic (X-ray) visualization of this area. In this example, the fenestration window 809 is oval, although other shapes are possible.
[0040] FIG. 9 illustrates a TPLO stabilized with an 8-hole TPLO bone plate 902 that is substantially similar to plate 802 shown in FIG. 8, and having a first portion 903a and second portion 903b. However, TPLO bone plate 902 has three fenestration windows (809a, 809b, 809c) to allow visualization of the osteotomy (e.g., osteotomy 105) intra-operatively and radiographically. The number of fenestration windows that can be used will range from 0 to 5 in some embodiments. In the example of FIG. 9, the fenestration windows 809a, 80b, and 809c are oval, although other shapes are possible.
[0041] FIG. 10 shows a TPLO bone plate 102 in the frontal plane. The bone plate 102 is pre-contoured to match the surface topography of the proximal medial tibia while spanning the osteotomy 105 and will not result in translation of the tibial lower portion 104 relative to the tibial upper portion 106. As previously depicted, for example in connection FIG. 1, the length LI of the first portion 103a of the bone plate and the length L2 of the second portion 103b of the bone plate are substantially similar to one another (within 25%) in at least some embodiments. In some embodiments, screws will be placed substantially parallel to the osteotomy 105. Note that with TPLO procedures, the osteotomy is typically made perpendicular to the long axis of the tibia and is assumed to be made as such for the purposes of this disclosure. Consequently, one could also conclude that screws that are substantially parallel to the osteotomy 105 are substantially perpendicular to the long axis of the tibia. The screws 101 illustrated in FIG. 10 represent an example of how the TPLO bone plate 102 is secured to the tibia, but are nonlimiting. Also, the illustrated locations of these screws 101 are not indicative of their actual location in the TPLO bone plate 102, but are depicted in FIG. 10 in a manner that allows them to be visible. In practice, the screws 101 might be superimposed when viewed in the frontal plane and therefore not all screws would be visible from this vantage point. In this embodiment of the TPLO bone plate 102 all screws are relatively perpendicular to the long axis of the tibia and parallel to the osteotomy 105. As shown, different types of screws 101 may be used with a single TPLO bone plate. For example, screw length and thread size may differ at different parts of the TPLO bone plate. Moreover, the screw trajectories may vary from that illustrated in FIG. 10 in different embodiments of the bone plate, an example being described below in connection with FIG. 11.
[0042] FIG. 11 shows a TPLO bone plate 1102 in the frontal plane. The bone plate 1102 is pre-contoured to match the surface topography of the proximal medial tibia while spanning the osteotomy 105 and will not result in translation of the tibial lower portion 104 relative to the tibial upper portion 106. TPLO bone plate 1102 is substantially similar in size and shape to TPLO bone plate 102 including with regards to lengths LI and L2 of the first and second portions of the TPLO bone plate. However, with some embodiments, such as TPLO bone plate 1102, not all screws will be placed substantially parallel to the osteotomy 105. Rather, the trajectory of some screws 101 can be substantially non-parallel to the osteotomy 105 and therefore, not perpendicular to the long axis of the tibia. In the embodiment of TPLO bone plate 1102, not all the screws 101 have trajectories parallel to the osteotomy 105.
[0043] FIG. 12 shows a TPLO bone plate 1202 in the frontal plane. The bone plate 1202 has a built-in step 1203 that will intentionally result in lateral translation of the tibial lower portion 104 relative to the tibial upper portion 106. Such TPLO bone plates will typically be used in patients with concurrent medial patella luxation in which lateral translation of the tibial crest is desired. Alternatively, such bone plates may be used in patients with severe cartilage erosion in the medial compartment of the knee/stifle and in which transfer of more mechanical load to the lateral compartment of the knee/stifle is desired. The size of the step 1203 will dictate the distance of translation and will range from 1 mm to 9 mm in different embodiments of the bone plate. The TPLO bone plate 1202 may have a first portion (below the step 1203) and second portion (above the step 1203) substantially the same as the first and second portions of TPLO bone plate 102 or any of other TPLO bone plates described herein. That is, TPLO bone plates may be made to have the shapes and sizes described herein, with the addition of a step like step 1203.
[0044] FIG. 13 shows a perspective view of a TPLO bone plate, similar to TPLO bone plate 102 shown in FIG. 1, with 6 round holes to accommodate angle-stable (locking) screws. Fig. 13 shows that the TPLO bone plate may have a thickness Tl. Tl may be sufficient to withstand forces upon the joined sections of the tibia. For example, the thickness Tl may be between 1.5 mm-4.5 mm in some embodiments, and most commonly between 2 mm and 3.5 mm. [0045] FIG. 14 shows a perspective view of a TPLO bone plate, similar to TPLO bone plate 202 shown in FIG. 2, with 6 total holes, 2 of which are oval and enable compression of an osteotomy.
[0046] Aspects of the present technology provide means for stabilizing a tibial plateau leveling osteotomy. Moreover, aspects of the present technology provide means for securing a lower portion of the tibia below the osteotomy without interfering with a semitendinosus tendon. The means may represent part of a TPLO bone plate. The TPLO bone plate may include an upper portion configured to be fixed to an upper portion of the tibia above the osteotomy, and may further include the means. Examples of the means are those portions of the TPLO bone plates described herein which are configured to be fixed to the tibia below the osteotomy.
[0047] Aspects of the present disclosure provide an improved method for tibial osteotomy stabilization in non-human animals. The tibial bone plate will allow placement of numerous screws in close proximity to both sides of the osteotomy without any requirement of the plate to extend a substantial distance down (distally) along the tibia. The plate will have multiple screw holes in a non-linear arrangement for placement on both sides of the osteotomy in close proximity to the osteotomy. For example, referring to FIGs. 1 and 4, the screw holes in the portions of those TPLO bone plates configured to be positioned above the osteotomy are in a non-linear arrangement (e.g., screw holes 107d, 107e, 107f). Likewise, the screw holes in the portions of the TPLO bone plates configured to be positioned below the osteotomy may also be non-linear, such as screw holes 107a, 107b, and 107c. Consequently, such TPLO bone plates will allow stabilization of the tibia in conjunction with tibial osteotomies with reduced requirement for soft tissue dissection including without the need to extend any dissection/surgical approach through or distal to the semitendinosus tendon on the medial tibia.
[0048] According to aspects of the present technology, the screws used with the bone plates described herein may be any suitable types of screws for securing the plate(s) to the tibia. The bone plates described herein allow for placement of screws toward the front of the plate (proximate the animal’s head) and the back of the plate (proximate the animal’s tail), as well as proximally (toward the top of the plate) to distally (toward the bottom of the plate).
[0049] According to aspects of the present technology, the bone plates according to various embodiments allow for placement of between 4-10 screws. Up to 5 holes may be positioned with the bone plate(s) on either side of the osteotomy. [0050] According to some embodiments, the screw holes of the bone plates are round, with no locking threads. According to alternative embodiments, the screw holes are round, with threads to accommodate locking (angle stable) screws. According to some embodiments, the holes do not have threads, but enable placement of angle-stable screws using a press-fit between the screws and holes. According to some embodiments, the holes are oval shaped holes to allow for compression of the osteotomy. According to some embodiments, the holes are snowman/figure-8 shaped holes that allow for placement of the screw in either end of the snowman- shaped holes and allow some compression of the osteotomy.
[0051] According to some embodiments, the bone plates are pre-contoured to the shape of the medial proximal tibia. The bone plates may allow application of either or both of anglestable and non-locking (i.e., not angle stable) screws and screws to create compression of the osteotomy. The angle stable type screws may use either a press fit mechanism or be threaded.
[0052] The bone plates described herein may be manufactured from titanium or titanium alloys, stainless steel or stainless steel alloys, cobalt base alloys such as (but not limited to) cobalt chrome, polymers, and ceramics, or other suitable materials.
[0053] The bone plates described herein may assume a variety of sizes to accommodate different size canines. Bone plates are often named for the diameter screw they accommodate, such as 3.5, 2.7, 2.4, 2.0, and 1.5 mm. According to embodiments of the present technology, the bone plates described herein may accommodate screws sizes of 4.5 mm, 4.0 mm, 3.5 mm, 3.0 mm, 2.7 mm, 2.4 mm, 2.0 mm, and 1.5 mm, or other sizes between 1.5 mm and 4.5 mm.
[0054] The TPLO bone plates described herein may have any suitable thickness (in a direction into and out of the page in FIGs. 1-3, and such as thickness T1 in FIGs. 13 and 14), such as 1.5 mm-4.5 mm and most commonly between 2 mm and 3.5 mm. The thickness of each plate will be of appropriate thickness to withstand forces upon the joined section. Because there is adequate muscle coverage in this area, thick bone plates are not problematic with regard to placement.
[0055] The holes 107d-107f are illustrated as round holes. Not all embodiments are limited in this respect. One or more of the holes 107d-107f may be oval holes (e.g., compression holes), snowman- shaped holes, or assume a different shape.
[0056] In some embodiments, the TPLO bone plates may include a step, such as 1203 in FIG. 12, in order to induce medial translation of the proximal segment medially with plate application. [0057] In some embodiment, the TPLO bone plates will have small holes, such as holes 608a and 608b in FIG. 6, that are round or oval, to allow placement of temporary holding wires while the TPLO is applied to the tibia.
[0058] According to an aspect of the present technology, a tibial plateau leveling osteotomy (TPLO) bone plate is provided. The TPLO bone plate comprises a first portion configured to be fixed to a lower portion of a tibia below an osteotomy. The first portion has a length between 7 mm and 4 cm and has a first row of multiple screw holes configured adjacent to the osteotomy. The TPLO bone plate further comprises a second portion configured to be fixed to an upper portion of the tibia above the osteotomy.
[0059] According to some embodiments, the TPLO bone plate is configured to be fixed without the use of an additional stabilization component.
[0060] According to some embodiments, the first portion and/or second portion of the TPLO bone plate comprises a compression screw hole.
[0061] According to some embodiments, the first portion of the TPLO bone plate has no more than five screw holes.
[0062] According to some embodiments, the first portion of the TPLO bone plate has four or fewer screw holes and the second portion of the TPLO bone plate has four or fewer screw holes.
[0063] According to some embodiments, the first portion and second portion of the TPLO bone plate are substantially symmetrical in length.
[0064] According to some embodiments, the first portion of the TPLO bone plate has a bulbous shape.
[0065] According to some embodiments, the second portion has a bulbous shape.
[0066] In some embodiments, the first portion and/or second portions has rounded comers and may be a polygon with rounded comers.
[0067] According to some embodiments, the TPLO bone plate further comprises a fenestration window configured to be positioned over the osteotomy.
[0068] According to some embodiments, the TPLO bone plate further comprises a plurality of fenestration windows configured to be positioned over the osteotomy.
[0069] According to an aspect of the present technology, a tibial plateau leveling osteotomy (TPLO) bone plate is provided, comprising an upper portion configured to be fixed to an upper portion of a tibia above an osteotomy, and means for securing a lower portion of the tibia below the osteotomy without interfering with a semitendinosus tendon.
[0070] According to some embodiments, the upper portion has a rounded shape, a shape with rounded corners, a polygon with rounded corners, or a bulbous shape.
[0071] According to some embodiments, the means for securing the lower portion of the tibia comprise a rounded shape, a shape with rounded comers, a polygon with rounded corners, or bulbous shape.
[0072] According to some embodiments, the means comprises multiple screw holes. The screw holes are, in some embodiments, arranged in multiple rows.
[0073] According to some embodiments, the means comprises three screw holes.
[0074] According to some embodiments, the means comprise a plurality of screw holes configured to be positioned approximately a same distance from the osteotomy.
[0075] According to an aspect of the present technology, a method of performing a tibial plateau leveling osteotomy (TPLO) on a patient is provided. The patient may be a canine or other four-legged animal. The method comprises creating an incision in the patient adjacent a tibia of the patient, cutting the tibia to form an upper portion and lower portion of the tibia separated by an osteotomy, and fixing a TPLO bone plate to the tibia to stabilize the osteotomy, without incising a semitendinosus tendon on a medial tibia and without positioning the TPLO bone plate underneath and distal to the semitendinosus tendon.
[0076] According to some embodiments, fixing the TPLO bone plate to the tibia comprises fixing a lower portion of the bone plate to the lower portion of the tibia with two screws placed substantially a same distance from the osteotomy.
[0077] According to some embodiments, fixing the TPLO bone plate to the tibia comprises fixing the lower portion of the bone plate to the lower portion of the tibia using only one additional screw beyond the two screws.
[0078] According to some embodiments, the TPLO bone plate has a lower portion configured to be fixed to the lower portion of the tibia, and fixing the TPLO bone plate to the tibia comprises positioning the lower portion of the TPLO bone plate to have a maximum distance from the osteotomy of less than 4 cm.
[0079] According to some embodiments, fixing the TPLO bone plate to the tibia comprises positioning the lower portion of the TPLO bone plate to have a maximum distance from the osteotomy of less than 2 cm. [0080] According to some embodiments, fixing the TPLO bone plate to the tibia comprises positioning the lower portion of the TPLO bone plate to have a maximum distance from the osteotomy of between 7 mm and 4 cm.
[0081] According to some embodiments, fixing the TPLO bone plate to the tibia comprises positioning the TPLO bone plate to have approximately a same length above and below the osteotomy.
[0082] Various aspects of the present disclosure may be used alone, in combination, or in a variety of arrangements not specifically described in the embodiments described in the foregoing and is therefore not limited in its disclosure to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.
[0083] The following benefits may be realized from one or more embodiments of the present application. Not all embodiments provide all benefits and benefits other than those now listed explicitly may be realized. The provision of a TPLO bone plate with a length designed not to extend substantially down the tibia of the patient avoids the need to incise the semitendinosus tendon or position the bone plate under the semitendinosus tendon in at least some embodiments. Thus, unnecessary damage to the semitendinosus tendon and other soft tissue from application of the bone plate may be avoided.
[0084] The provision of a TPLO bone plate with multiple screw holes on either side of the osteotomy and close to the osteotomy may provide for increased stabilization of the osteotomy. Additional tools beyond the bone plate and screws - such as an additional stabilization plate or wedge inserted into the osteotomy - may be avoided. Thus, the surgical repair procedure may also be simplified compared to procedures involving the insertion of additional components.
[0085] The plates described herein according to at least some embodiments allow placement of numerous screws in bone on both sides of the osteotomy with the screw holes in the plate arranged in a cranial-caudal direction in addition to a proximal-distal direction instead of having screw holes in a distal portion of the bone plate just in a proximal-distal direction. Such placement reduces the overall length of the plate and allows the plate to be applied through a smaller incision. Accordingly, implantation of these plates does not require dissection that encroaches upon the semitendinosus tendon. Accordingly, numerous screws may be placed close to the osteotomy site rather than at a distance from the osteotomy site.
[0086] The TPLO bone plates described herein may be used for stabilization of other fractures or osteotomies in veterinary patients including fractures of the proximal tibia and distal femoral osteotomies or fractures.
[0087] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
[0088] The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified.
[0089] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.
[0090] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.
[0091] The terms “approximately” and “about” may be used to mean within ±20% of a target value in some embodiments, within ±10% of a target value in some embodiments, within ±5% of a target value in some embodiments, and yet within ±2% of a target value in some embodiments. The terms “approximately” and “about” may include the target value. [0092] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0093] Having described above several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be object of this disclosure. Accordingly, the foregoing description and drawings are by way of example only.