Technique and instrument for ischium osteotomy during periacetabular osteotomy

Abstract

An apparatus is described herein comprising an osteotome and a sheath, wherein the proximal end of the osteotome comprises a handle, wherein the distal end of the osteotome comprises a blade, wherein an intermediate stem joins the handle and the blade, the proximal end of the sheath comprising an attachment component, wherein a surface of the distal end of the sheath comprises a hollowed region, wherein the hollowed region comprises a stem, the proximal end of the stem comprising a securing component for receiving and securing the attachment component of the sheath, the blade comprising a blade curvature, wherein a surface of the blade curvature comprises a recessed opening, the recessed opening, and the stem, the attachment component, and the securing component configured to cooperate in securing the sheath to the blade.

Description

[0001] UNITED STATES PATENT APPLICATION FOR:

[0002] TECHNIQUE AND INSTRUMENT FOR ISCHIUM OSTEOTOMY DURING

[0003] PERIACETABULAR OSTEOTOMY

[0004] RELATED APPLICATIONS

[0005] This application claims the benefit of United States Application No. 63 / 635,993, filed April 18, 2024.

[0006] TECHNICAL FIELD

[0007] The disclosure herein involves method of reducing risk in the use of an osteotome for certain medical procedures.

[0008] BACKGROUND

[0009] Periacetabular osteotomy (PAO) is a surgical procedure that changes the angle of the hip socket so that the ball-shaped femoral head fits more securely inside of it. A periacetabular osteotomy (PAO) is the main surgical treatment for adolescents and young adults with hip dysplasia who experience hip pain and are limited in their daily function. The long-term goal of the procedure is to preserve the hip joint and decrease the risk of developing arthritis. In the short term, PAO can restore hip stability, reduce hip pain, and improve function. If a PAO is performed before advanced hip arthritis is present, it may serve as a lifelong treatment. During PAO, the hip preservation orthopedic surgeon makes a series of cuts to the bone (osteotomies) around the hip socket to rotate the socket into proper position. Once the socket is repositioned, the surgeon inserts metal screws to hold the bone in place while it heals. The goal of this procedure is to allow the hip socket to provide better coverage of the top of the femur (femoral head) and reduce stress on the rim of the hip socket (acetabulum) that otherwise causes cartilage damage.

[0010] INCORPORATION BY REFERENCE

[0011] Each patent, patent application, and / or publication mentioned in this specification is herein incorporated by reference in its entirety to the same extent as if each individual patent, patent application, and / or publication was specifically and individually indicated to be incorporated by reference.

[0012] SUMMARY OF THE INVENTION

[0013] An apparatus is described herein comprising an osteotome and a sheath, wherein the proximal end of the osteotome comprises a handle, wherein the distal end of the osteotome comprises a blade, wherein an intermediate stem joins the handle and the blade, the proximal end of the sheath comprising an attachment component, wherein a surface of the distal end of the sheath comprises a hollowed region, wherein the hollowed region comprises a stem, the proximal end of the stem comprising a securing component for receiving and securing the attachment component of the sheath, the blade comprising a blade curvature, wherein a surface of the blade curvature comprises a recessed opening, and the recessed opening, the stem, the attachment component, and the securing component configured to cooperate in securing the sheath to the blade, wherein the securing comprises inserting the stem into the recessed opening, wherein the securing comprises coupling the attachment component to the securing component.

[0014] In embodiment, the sheath is dimensioned so that the coupling anchors the stem in place within the recessed opening.

[0015] In embodiment, the attachment component comprises an attachment clip.

[0016] In embodiment, the securing component comprises an upper proximal portion of the stem.

[0017] In embodiment, the coupling snaps the attachment clip onto the upper proximal portion of the stem.

[0018] In embodiment, the attachment clip snaps into place adjacent to a partial collar surrounding a proximal lower portion of the sheath.

[0019] In embodiment, the attachment component comprises a receiving hole.

[0020] In embodiment, the securing component comprises a column located on the stem proximate the distal end of the handle.

[0021] In embodiment, the coupling snaps the column into the receiving hole. In embodiment, the attachment component comprises a recessed attachment clip, wherein the recessed attachment clip comprises two grooves in opposing inner surfaces of the attachment clip.

[0022] In embodiment, the securing component comprises two tongues extending laterally in opposing directions at a location on the stem proximate the distal end of the handle.

[0023] In embodiment, the coupling comprises snapping the recessed attachment clip and grooves over and onto the tongues such the recessed attachment clip is secured to the stem in a tongue and groove configuration.

[0024] In embodiment, the coupling comprises snapping the recessed attachment clip onto the stem at a location proximate the tongues.

[0025] In embodiment, the coupling comprises sliding the grooves over the tongues to secure the recessed attachment clip to the stem in a tongue and groove configuration.

[0026] In embodiment, the distal end of the sheath comprises a protective blade covering.

[0027] In embodiment, the securing the sheath to the osteotome locates the protective covering over and extending beyond the blade.

[0028] In embodiment, the protective covering comprises an extension layer, wherein the extension layer increases a thickness of the protective covering when it extends beyond a cutting tip of the blade.

[0029] In embodiment, the lower surface of the extension layer follows a trajectory of the blade curvature.

[0030] An apparatus is described herein comprising an osteotome and a sheath, wherein a proximal end of the osteotome comprises a handle, wherein the distal end of the osteotome comprises a blade, wherein an intermediate stem joins the handle and the blade, the proximal end of the sheath comprising an attachment component, wherein the distal end of the sheath comprises downwardly projecting wings disposed on opposing sides of the sheath, wherein each wing comprises an inwardly projecting post, wherein the inwardly projecting posts create respective slide grooves between the posts and the lower surface of the sheath distal end, the proximal end of the stem comprising a securing component for receiving and securing the attachment component, the blade comprising recessed slide stops disposed on opposing sides of the blade, and the slide stops, the downwardly projecting wings, the attachment component, and the securing component configured to cooperate in securing the sheath to the blade, wherein the securing comprises sliding the grooves onto the blade until rear walls of the grooves contact the slide stops.

[0031] In embodiment, the attachment component comprises an attachment clip.

[0032] In embodiment, the securing component comprises an upper proximal portion of the stem.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A shows a chisel edge, under an embodiment.

[0035] Figure IB shows an osteotome edge, under an embodiment.

[0036] Figure 2 shows a mast osteotome, under an embodiment.

[0037] Figure 3A shows a sheath system comprising an attachment assembly, sheath, and locking pin, under an embodiment.

[0038] Figure 3B shows a sheath system comprising an attachment assembly, sheath, and locking pin, under an embodiment.

[0039] Figure 3C shows a sheath system comprising an attachment assembly, sheath, and locking pin, under an embodiment.

[0040] Figure 3D shows a sheath system comprising an attachment assembly, sheath, and locking pin, under an embodiment.

[0041] Figure 4A shows an attachment assembly, under an embodiment.

[0042] Figure 4B shows an attachment assembly, under an embodiment.

[0043] Figure 4C shows an attachment assembly, under an embodiment.

[0044] Figure 5 shows deployment of a sheath on the attachment assembly prior to insertion of locking pin, under an embodiment.

[0045] Figure 6A shows a perspective view of a sheath secured to attachment assembly using a locking pin, under an embodiment.

[0046] Figure 6B shows a perspective view of sheath secured to attachment assembly using a locking pin, under an embodiment.

[0047] Figure 7A provides a rear view of the upper component, under an embodiment.

[0048] Figure 7B provides a bottom view of the upper component, under an embodiment.

[0049] Figure 7C provides a front view of the upper component, under an embodiment.

[0050] Figure 7D provides a top view of the upper component, under an embodiment.

[0051] Figure 7E provides a left view of the upper component, under an embodiment. Figure 7F provides a perspective view of the upper component, under an embodiment.

[0052] Figure 7G provides a perspective view of the upper component, under an embodiment.

[0053] Figure 8A provides a rear view of the lower component, under an embodiment.

[0054] Figure 8B provides a front view of the lower component, under an embodiment.

[0055] Figure 8C provides a top view of the lower component, under an embodiment.

[0056] Figure 8D provides a perspective view of the lower component, under an embodiment.

[0057] Figure 8E provides a perspective view of the lower component, under an embodiment.

[0058] Figure 9A shows a side view of a sheath, under an embodiment.

[0059] Figure 9B shows a top view of a sheath, under an embodiment.

[0060] Figure 9C shows a bottom view of a sheath, under an embodiment.

[0061] Figure 9D shows a front view of a sheath, under an embodiment.

[0062] Figure 9E shows a back view of a sheath, under an embodiment.

[0063] Figure 9F shows a perspective view of a sheath, under an embodiment.

[0064] Figure 9G shows a perspective view of a sheath, under an embodiment.

[0065] Figure 10A shows a front view of a sheath lock pin, under an embodiment.

[0066] Figure 10B shows a right view of a sheath lock pin, under an embodiment.

[0067] Figure IOC shows a top view of a sheath lock pin, under an embodiment.

[0068] Figure 10D shows a bottom view of a sheath lock pin, under an embodiment.

[0069] Figure 10E shows a perspective view of a sheath lock pin, under an embodiment.

[0070] Figure 11A shows a perspective view of a sheath, under an embodiment.

[0071] Figure 11B shows a side view of a sheath, under an embodiment.

[0072] Figure 11C shows a bottom view of a sheath, under an embodiment.

[0073] Figure 12 shows a sheath system comprising a collar mechanism, under an embodiment.

[0074] Figure 13 shows a sheath with clip component under an embodiment, under an embodiment.

[0075] Figure 14A shows a sheath system comprising a collar mechanism, under an embodiment.

[0076] Figure 14B shows a sheath system comprising a collar mechanism, under an embodiment.

[0077] Figure 14C shows a sheath system comprising a collar mechanism, under an embodiment.

[0078] Figure 15 shows introduction of flex into the sheath during deployment, under an embodiment.

[0079] Figure 16A shows an alternative sheath and osteotome configuration, under an embodiment.

[0080] Figure 16B shows an alternative sheath and osteotome configuration, under an embodiment.

[0081] Figure 16C shows an alternative sheath and osteotome configuration, under an embodiment. Figure 17 illustrates potential damage that may occurs as a curved osteotome blade is brought to the hip bone, under an embodiment.

[0082] Figure 18 shows a sheath system comprising a collar mechanism, under an embodiment.

[0083] Figure 19 shows a sheath system comprising a collar mechanism, under an embodiment.

[0084] Figure 20 shows a sheath system comprising a collar mechanism, under an embodiment.

[0085] Figure 21 shows a sheath system comprising a collar mechanism, under an embodiment.

[0086] Figure 22 shows deployment of a sheath system in a Periacetabular Osteotomy Model, under an embodiment.

[0087] Figure 23A shows a perspective view of an osteotome configured for sheath clip attachment, under an embodiment.

[0088] Figure 23B shows a perspective view of an osteotome configured for sheath clip attachment, under an embodiment.

[0089] Figure 23C shows a rear view of an osteotome configured for sheath clip attachment, under an embodiment.

[0090] Figure 23D shows a front view of an osteotome configured for sheath clip attachment, under an embodiment.

[0091] Figure 23E shows a bottom view of an osteotome configured for sheath clip attachment, under an embodiment.

[0092] Figure 23F shows a side view of an osteotome configured for sheath clip attachment, under an embodiment.

[0093] Figure 23G shows a top view of an osteotome configured for sheath clip attachment, under an embodiment.

[0094] Figure 24A shows a top view of a sheath with clip attachment, under an embodiment.

[0095] Figure 24B shows a side view of a sheath with clip attachment, under an embodiment.

[0096] Figure 24C shows a bottom view of a sheath with clip attachment, under an embodiment.

[0097] Figure 24D shows a perspective view of a sheath with clip attachment, under an embodiment.

[0098] Figure 24E shows a perspective view of a sheath with clip attachment, under an embodiment.

[0099] Figure 24F shows a front view of a sheath with clip attachment, under an embodiment.

[0100] Figure 24G shows a rear view of a sheath with clip attachment, under an embodiment. Figure 24H shows a side view of attaching the sheath with clip attachment, under an embodiment.

[0101] Figure 241 shows a side view of attaching the sheath with clip attachment, under an embodiment.

[0102] Figure 24J shows a perspective view of attaching the sheath with clip attachment, under an embodiment.

[0103] Figure 24K shows a perspective view of attaching the sheath with clip attachment, under an embodiment.

[0104] Figure 24L shows a perspective view of attaching the sheath with clip attachment, under an embodiment.

[0105] Figure 24M shows a front view of attaching the sheath with clip attachment, under an embodiment.

[0106] Figure 24N shows a perspective view of attaching the sheath with clip attachment, under an embodiment.

[0107] Figure 240 shows a close up of sheath distal end, under an embodiment.

[0108] Figure 24P shows a close up of sheath proximal end, under an embodiment.

[0109] Figure 24Q shows a side view of sheath and blade distal ends in a deployed state, under an embodiment.

[0110] Figure 25A shows a perspective view of an osteotome configured for column clip attachment, under an embodiment.

[0111] Figure 25B shows a perspective view of an osteotome configured for column clip attachment, under an embodiment.

[0112] Figure 25C shows a rear view of an osteotome configured for column clip attachment, under an embodiment.

[0113] Figure 25D shows a front view of an osteotome configured for column clip attachment, under an embodiment.

[0114] Figure 25E shows a bottom view of an osteotome configured for column clip attachment, under an embodiment.

[0115] Figure 25F shows a side view of an osteotome configured for column clip attachment, under an embodiment.

[0116] Figure 25G shows a top view of an osteotome configured for column clip attachment, under an embodiment. Figure 26A shows a top view of a sheath configured to receive an osteotome column, under an embodiment.

[0117] Figure 26B shows a side view of a sheath configured to receive an osteotome column, under an embodiment.

[0118] Figure 26C shows a bottom view of a sheath configured to receive an osteotome column, under an embodiment.

[0119] Figure 26D shows a perspective view of a sheath configured to receive an osteotome column, under an embodiment.

[0120] Figure 26E shows a perspective view of a sheath configured to receive an osteotome column, under an embodiment.

[0121] Figure 26F shows a front view of a sheath configured to receive an osteotome column, under an embodiment.

[0122] Figure 26G shows a rear view of a sheath configured to receive an osteotome column, under an embodiment.

[0123] Figure 26H shows a side view of attaching the sheath using a column configuration, under an embodiment.

[0124] Figure 261 shows a side view of attaching the sheath using a column configuration, under an embodiment.

[0125] Figure 26J shows a perspective view of attaching the sheath using a column configuration, under an embodiment.

[0126] Figure 26K shows a perspective view of attaching the sheath using a column configuration, under an embodiment.

[0127] Figure 26L shows a perspective view of attaching the sheath using a column configuration, under an embodiment.

[0128] Figure 26M shows a front view of attaching the sheath using a column configuration, under an embodiment.

[0129] Figure 26N shows a perspective view of attaching the sheath using a column configuration, under an embodiment.

[0130] Figure 27A shows a perspective view of an osteotome with slide attachment, under an embodiment.

[0131] Figure 27B shows a perspective view of an osteotome with slide attachment, under an embodiment.

[0132] Figure 27C shows a rear view of an osteotome with slide attachment, under an embodiment. Figure 27D shows a front view of an osteotome with slide attachment, under an embodiment.

[0133] Figure 27E shows a bottom view of an osteotome with slide attachment, under an embodiment.

[0134] Figure 27F shows a side view of an osteotome with slide attachment, under an embodiment.

[0135] Figure 27G shows a top view of an osteotome with slide attachment, under an embodiment.

[0136] Figure 28A shows a top view of a sheath slide clip attachment, under an embodiment.

[0137] Figure 28B shows a side view of a sheath slide clip attachment, under an embodiment.

[0138] Figure 28C shows a bottom view of a sheath slide clip attachment, under an embodiment.

[0139] Figure 28D shows a perspective view of a sheath slide clip attachment, under an embodiment.

[0140] Figure 28E shows a perspective view of a sheath slide clip attachment, under an embodiment.

[0141] Figure 28F shows a front view of a sheath slide clip attachment, under an embodiment.

[0142] Figure 28G shows a rear view of a sheath slide clip attachment, under an embodiment.

[0143] Figure 28H shows a side view of attaching the sheath with slide clip attachment, under an embodiment.

[0144] Figure 281 shows a side view of attaching the sheath with slide clip attachment, under an embodiment.

[0145] Figure 28J shows a perspective view of attaching the sheath with slide clip attachment, under an embodiment.

[0146] Figure 28K shows a perspective view of attaching the sheath with slide clip attachment, under an embodiment.

[0147] Figure 28L shows a perspective view of attaching the sheath with slide clip attachment, under an embodiment.

[0148] Figure 28M shows a front view of attaching the sheath with slide clip attachment, under an embodiment.

[0149] Figure 28N shows a rear view of attaching the sheath with slide clip attachment, under an embodiment..

[0150] Figure 29 illustrates a sheath attached to an osteotome in an attachment clip configuration, under an embodiment.

[0151] Figure 30 illustrates a sheath attached to an osteotome in column configuration, under an embodiment. Figure 31 illustrates a sheath in the process of attachment to an osteotome in a slide configuration, under an embodiment.

[0152] Figure 32 illustrates a sheath attached to an osteotome in an attachment clip configuration., under an embodiment.

[0153] Figure 33A shows a perspective view of an osteotome configured for inverse slide configuration, under an embodiment.

[0154] Figure 33B shows a perspective view of an osteotome configured for inverse slide configuration, under an embodiment.

[0155] Figure 33C shows a rear view of an osteotome configured for inverse slide configuration, under an embodiment.

[0156] Figure 33D shows a front view of an osteotome configured for inverse slide configuration, under an embodiment.

[0157] Figure 33E shows a bottom view of an osteotome configured for inverse slide configuration, under an embodiment.

[0158] Figure 33F shows a side view of an osteotome configured for inverse slide configuration, under an embodiment.

[0159] Figure 33G shows a top view of an osteotome configured for inverse slide configuration, under an embodiment.

[0160] Figure 34A shows a top view of a sheath comprising an inverse slide, under an embodiment.

[0161] Figure 34B shows a side view of a sheath comprising an inverse slide, under an embodiment.

[0162] Figure 34C shows a bottom view of a sheath comprising an inverse slide, under an embodiment.

[0163] Figure 34D shows a perspective view of a sheath comprising an inverse slide sheath, under an embodiment.

[0164] Figure 34E shows a perspective view of a sheath comprising an inverse slide, under an embodiment.

[0165] Figure 34F shows a front view of a sheath comprising an inverse slide, under an embodiment. Figure 34G shows a rear view of a sheath comprising an inverse slide, under an embodiment.

[0166] Figure 34H shows a side view of attaching a sheath with inverse slide configuration, under an embodiment.

[0167] Figure 341 shows a side view of attaching a sheath with inverse slide configuration, under an embodiment.

[0168] Figure 34J shows a perspective view of attaching a sheath with inverse slide configuration, under an embodiment.

[0169] Figure 34K shows a perspective view of attaching a sheath with inverse slide configuration, under an embodiment.

[0170] Figure 34L shows a perspective view of attaching a sheath with inverse slide configuration, under an embodiment.

[0171] Figure 34M shows a front view of attaching a sheath with inverse slide configuration, under an embodiment.

[0172] Figure 34N shows a perspective view of attaching a sheath with inverse slide configuration, under an embodiment.

[0173] DETAILED DESCRIPTION

[0174] An osteotome is an orthopedic instrument that is typically used for cutting bone. A chisel is used for shaping bone. Functionally, the primary difference is that a chisel has one beveled edge (Figure 1A), while an osteotome has two beveled edges (Figure IB).

[0175] In hip surgeries, specifically periacetabular osteotomies (PAO), a mast osteotome is used. The mast osteotome is unique in that it has a curved blade, as an angled approach is necessary to make the intended cuts in the pelvis. Once the osteotome blade reaches bone, the surgeon can hit the broad handle end with a mallet to make cuts. Figure 2 provides an image of a mast osteotome, under an embodiment.

[0176] A modified osteotome with protective sleeve for the ischial osteotomy during periacetabular osteotomy (PAO) is described herein. This is a modified version of the mast osteotome / chisel with a protective sleeve that covers the blade. This sleeve protects soft tissue structures as the osteotome is inserted. The sleeve can be retracted or removed when the osteotome has been advanced to the ischium and the surgeon is ready to make the bone cut. The sleeve may be designed with a slightly convex shape similar to large Mayo scissors to facilitate passage into the wound. The sleeve may have length / setting options which limits how deep the osteotome can be inserted, e.g. 1.5 - 4 cm in 0.5cm increments. An alternative design comprises linking plastic components that sit on top of and underneath the blade and shaft of the osteotome. The sheets could be separated with a switch near the handle or other means of fastening the sheets together and then each sheet could be withdrawn separately from the wound. An alternative design could involve modification of the osteotome, such as the handle or shaft, such that the retractable / removable sleeve attaches directly to the osteotome.

[0177] The apparatus described herein can be used anytime an osteotomy is being used to cut a bone deep in a wound to facilitate passage through soft tissue. In some variations it could also prevent plunging if the sleeve is retractable with depth settings. The osteotome sleeve described herein is primarily designed for the ischial osteotomy during PAO's but is also relevant to other osteotomies. For example, a sleeve that prevents plunging with depth settings could be useful for the pubic ramus osteotomy during PAO's.

[0178] During PAO, there is a risk of neurovascular and soft tissue damage as the osteotome is brought to the hip bone. Specific features at risk are the sciatic nerve, which is damaged in 1.7% of PAO surgeries, and the obturator artery and surrounding small vessels, which may contribute to the 2.3% rate of bleeding complications in PAO surgeries. These lesions can result in longer hospital stays and longer healing times, carrying a risk of lifelong damage.

[0179] While the complication rates mentioned above are not attributed solely to osteotome related injury, we believe that exposure of the osteotome blade as it is brought to the bone is an unnecessary risk factor to soft tissue and neurovascular damage. Blade guards are common on commercial osteotomes, and help with alignment, but they do not shield the blade completely as it descends to the hip bone. An existing workaround to protect surrounding tissue is the development of surgical maneuvers. While these decrease risks of damaging neurovascular structures, they may increase the procedure's operating time and be more difficult for training surgeons to accomplish.

[0180] A flexible sheath system is described herein that covers the osteotome blade as it is brought through soft tissue to the bone and can be removed by the surgeon once the osteotome blade is correctly aligned with the bone. The osteotome sheath has three major components. An attachment assembly for attachment of a sheath to the osteotome, the sheath itself, and a locking pin mechanism.

[0181] First, the osteotome sheath system is locked onto the osteotome via an attachment assembly. The attachment assembly may either function as a clamp or clip onto the handle of the osteotome, or a clamp or clip attached to the base of the osteotome blade, near the handle. The attachment assembly serves as the base of attachment of the sheath to the osteotome, such that the osteotome sheath can be adj usted and removed once the functional blade of the osteotome is already in use or in place at the bone.

[0182] Figures 3 A, 3B, 3C, and 3D show an attachment assembly 302 of an osteotome sheath system in a disconnected and connected state, under an embodiment. The attachment assembly includes an upper component 304, a lower component 306, and a sheath 322. As seen in Figures 4 A, 4B, and 4C, the upper component 304 and lower component 306 each feature a crescent shaped recess 314, 316 for surrounding and securing to the base of the osteotome blade 320.

[0183] The lower component features a securing post 310 comprising a column of stacked spheres. The stacked configuration provides four longitudinally dispersed neck-like recesses. The upper component 304 comprises receiving through holes 312 configured to receive the corresponding securing post 310. In securing the upper component to the lower component, each receiving hole passes over the respective securing post and snaps into one of the neck like recesses depending upon size of the base of the osteotome blade 320.

[0184] Figure 5 shows deployment of the sheath 322 on the attachment assembly prior to insertion of locking pin 324. Figure 6A shows a perspective view of sheath 322 secured to attachment assembly 302 using a locking pin. Figure 6B shows a perspective view of sheath 322 secured to an attachment assembly 302 (and thereby to the osteotome) using a locking pin. Deployment of the sheath onto the attachment assembly is further described below.

[0185] Figures 7A-7G show various views of an upper component, under an embodiment.

[0186] Figures 8A-8E show various views of a lower component, under an embodiment.

[0187] Figure 9A shows a side view of the osteotome sheath 322. The sheath includes a proximal end 902 and a distal end 904. The proximal end features a handle 906 for positioning the sheath onto the osteotome blade. The distal end of the sheath comprises a bulb 908 and blunt 910 feature further described below. An integrally formed attachment rail 920 extends from the sheath’s proximal end along a surface opposite the handle. The rail is dowel shaped (as seen in Figure 9G) and includes equally spaced longitudinally distributed through holes 922.

[0188] The upper component 302 of the attachment assembly comprises a crescent shaped through hole 330 (see Figure 4B) dimensioned to receive the dowel shaped rail 920. In securing the sheath to the osteotome, the attachment assembly is first attached to the to the osteotome as already described above (see Figures 3A-6B). The rail 920 passes through crescent shaped receiving hole 330 of the upper component 304. The sheath then slides into place such that the bulb 908 fits into the curvature at the osteotome’s distal end and the blunt tip 910 extends over the osteotome’s blade. A sheath lock pin 324 then passes through a receiving hole 922 of the attachment rail 920 (see Figure 9) and receiving holes 326, 328 of the attachment assembly upper component 302 (see Figure 4A). A proximal end of the sheath lock pin 324 features a dual winged flange. In a deployed state, one wing of the flange rotates into a receiving slot 332 of the attachment assembly upper component 302 to secure the sheath in position (see Figure 4C and 6B). Figures 10A-10D show various views of a sheath lock pin.

[0189] The osteotome sheath has a bulb on the underside, such that it fits into the curvature of the osteotome blade and shields the blade as the osteotome is brought through soft tissue. The osteotome sheath also features a blunt tip to aid in traversing the narrow corridor of soft tissue as the osteotome is brought to the bone. The sheath is kept tight onto the osteotome blade via outside force from the tissue corridor, as well as material properties of the sheath itself. The sheath is intended to be flexible in that securing the sheath to the attachment causes the sheath to bend, and the elastic force of the sheath keeps it in line with the curvature of the osteotome blade. See Figure 15 for introduction of flex into the sheath during deployment.

[0190] Once the sheath is in the desired position, the user can lock the sheath in place using a pin. The pin is placed such that it locks the sheath to the attachment assembly on the osteotome. Within the sheath, there are multiple pin slots such that the osteotome sheath system may be used with different sized osteotomes, which may have varying blade lengths.

[0191] After setting up the osteotome sheath system, the blade is protected by the sheath and the sheath and attachment system are secured onto the osteotome. The user can then use the osteotome as usual, bringing the osteotome through soft tissue to where they would like to make a cut in the bone. Once the osteotome is in the desired position, the user can remove the pin, slide the sheath back out of the attachment assembly, and align the uncovered osteotome blade directly to the bone. After making the desired cut, the osteotome can be removed from the patient. If more cuts are desired, the user can reset the sheath onto the attachment system, place the pin to lock the sheath in place, and perform the process over again. Once the procedure is completed, the attachment assembly can be removed from the osteotome handle or base of the blade.

[0192] Under an alternative embodiment, a sheath includes rectangular through holes (or locking cavities) at its proximal end that extend through the sheath itself (see Figures 11 A, 1 IB, 11C, 14). Under this alternative embodiment, a collar or sleeve (see Figures 14, 18-21) slides over the osteotome handle. A screw based guide clamp secures the collar to the handle. The collar then receives the sheath and a locking bar whereby the locking bar cooperates with the locking cavities to secure the sheath in place. Under an alternative embodiment, a sheath simply attaches to an osteotome using a clip mechanism (see Figure 13).

[0193] As indicated above, an Osteotome is a chisel-like blade used to cut bone during orthopedic surgery. The osteotome features a grasping handle and a hardened steel stalk with an angled end. The distal end of the osteotome comprises a curved double sided blade between two blunt guards. (See Figure 2).

[0194] During peri acetabular osteotomies (PAOs), there is a risk of neurovascular and soft tissue damage as the curved osteotome blade is brought to the pelvic bone. Risks of PAO specific injuries include: Lateral Femoral Cutaneous Nerve, Sciatic Nerve Damage, Femoral Nerve, and Bleeding Complications. Lesion effects include longer hospital stays and longer healing times, or lifelong damage. Figure 17 illustrates such risks.

[0195] A protective sheath described herein fully envelopes the curved osteotome blade and reduces such risks. As described above, a sheath comprises a dissection aiding extension, a protective bulb, and locking cavities. An attachment sleeve is secured to the osteotome handle with a screw-based guide clamp. The deployed sheath is secured to the attachment sleeve with a locking bar which passes through the sleeve and a locking cavity to secure the sheath in place.

[0196] Under an embodiment, this osteotome sheath system is designed for the mast osteotome and / or other curved osteotomes used in hip preservation surgeries. The mast osteotome comprises a divet where the blade exists and blade guards surrounding the divet. Therefore, the bulb of the sheath remains secure on top of the blade. The sheath system may be applicable to additional types of osteotomes that feature a similar blade design to the mast osteotome.

[0197] Under an alternative embodiment, the same attachment assembly works for osteotomes with similarly sized blades and handles. The attachment assembly is under another embodiment adjustable such that it can be tightened more onto osteotomes with smaller handles or blade bases. Due to the variability in osteotome sizes, a range of attachment assemblies may be designed for general size categories such that an attachment is available for the smallest to largest osteotomes.

[0198] As already described above, an osteotome is an orthopedic instrument that is typically used for cutting bone. A chisel is used for shaping bone. Functionally, the primary difference is that a chisel has one beveled edge (Figure 1 A), while an osteotome has two beveled edges (Figure IB). In hip surgeries, specifically periacetabular osteotomies (PAO), a mast osteotome is used. The mast osteotome is unique in that it has a curved blade, as an angled approach is necessary to make the intended cuts in the pelvis (and potentially other locations). Once the osteotome blade reaches bone, the surgeon can hit the broad handle end with a mallet to make cuts. Figure 2 provides an image of a mast osteotome, under an embodiment.

[0199] Figures 23A-23G show an osteotome 2300, under an embodiment. The osteotome comprises a handle 2302 at its proximal end and a blade 3204 at its distal end. The blade is integrally formed with a stem 2318 which attaches to the handle. The blade 2034 comprises a curvature. A lower surface of the curvature illustrates an integrally formed recess component 2320. Under an embodiment, the recess component protrudes from the lower surface and features a recess 2322 (facing in direction of the handle) dimensioned to receive a post 2412 integrally formed into a sheath (see Figure 24D and 240, 2412) as further described below.

[0200] The union of the blade stem 2318 proximal end with the handle 2302 distal end features an attachment structure 2330 (otherwise referred to as securing structure or securing component) integrally formed with the stem 2318. Under an embodiment, the attachment structure 2330 comprises a partial collar surrounding a portion of the stem 2318 adjacent the handle 2302 distal end at the point of union. The partial collar leaves a remainder of the stem at the point of union exposed for receiving a sheath clip attachment (see Figure 24D and 24P, 2404) as further described below.

[0201] Figures 24A-24G illustrate a sheath 2400. A proximal end of the sheath comprises a guiding handle 2402 and clip attachment 2404 (otherwise referred to as an attachment component). A distal end of the sheath comprises a hollowed rectangular region 2414. The proximal end of the hollowed region 2414 comprises a post 2412 which extends into the hollowed region 2414. (Figures 240 and 24P show a close of clip attachment 2404, hollowed region 2414, and post 2412). In attaching a sheath 2400 to the osteotome 2300, a user guides the post 2412 of the sheath into the recess 2322 of the osteotome 2300. A user then snaps the attachment clip 2404 around the stem 2318 directly above the attachment structure 2330 (i.e. the collar). The sheath is dimensioned such that attaching the clip to the stem anchors the post 2412 within the recess 2322. The sheath is immobile as it abuts the handle at its proximal end in the deployed state and thereby maintains position of the post within the recess.

[0202] Figure 24Q shows a distal end side view of a sheath 2400 deployed on the blade stem 2318 and blade 2304 distal end. In attaching the sheath 2400, a user guides the post 2412 of the sheath into the recess 2322 of the osteotome 2300. As described above, the post 2412 is anchored within the recess by the attachment mechanism. In a deployed state, the curvature of the sheath 2400 distal end matches the curvature of the blade 2304 distal end. Note that the distal end of the sheath 2400 comprises an extension layer which increases the sheath's thickness when it extends beyond the blade tip (see Figures 24B and 24D, 2430). The lower surface of the blade 2304 distal end and lower surface to the sheath extension layer 2430 (see also Figures 24B and 24D) follow a common line of curvature. In this configuration, the sheath 2400 distal end provides a protective "blade tip" covering of the blade 2304 distal end while acting as a functional non-cutting extension of the blade itself. (Note that the side view of Figure 24Q also illustrates the hollowed region 2414 in the lower surface of sheath 2400 distal end).

[0203] Figures 24H-24N illustrates the process of attaching the sheath to osteotome using a clip attachment configuration.

[0204] Additional embodiments of osteotome and sheath couplings include a column attachment and slide attachment configuration. All aspects of the osteotome and sheath coupling described above remain the same or essentially the same with respect to these additional embodiments. However, the attachment structure 2330 (i.e. the collar) on the osteotome described above and the clip attachment clip 2404 on the sheath described above assume different configurations with respect to these additional embodiments and will be described below.

[0205] Figures 25A-26N illustrate various views of an osteotome 2500 and / or sheath 2600 each configured for column attachment. As seen in Figures 25A, 25B, 25E, and 25F an alternative to the attachment structure 2330 comprises a column 2510. Under this embodiment, the column 2510 protrudes from the sheath stem 2318 in close proximity to the handle 2302 distal end. As seen in Figures 26C, 26D, and 26E, the attachment clip mechanism assumes the form a through hole 2620 at the proximal end of the sheath.

[0206] In attaching a sheath 2500 to the osteotome 2600, a user guides the post 2412 of the sheath into the recess 2322 of the osteotome 2600 (as described in great detail above). A user then press fits the column 2510 into the through hole 2620. The sheath is dimensioned such that attaching the clip to the stem anchors the post 2412 within the recess 2322. The sheath is immobile as it is held in place by the column attachment configuration and thereby maintains position of the post within the recess.

[0207] Figures 26H-26N illustrate the process of attaching the sheath to the osteotome in a slide attachment configuration.

[0208] Figures 27A-28N illustrate various views of an osteotome 2700 and / or sheath 2800 each configured for slide attachment. As seen in Figures 27A, 27B, 27E, and 27F an alternative to the attachment structure 2330 comprises laterally extending protrusions (or tongues) 2710. Under this embodiment, two protrusions 2720 laterally extend from the stem 2318 in opposing directions and in close proximity to the handle 2302 distal end. As seen in Figures 28 A, 28B, 28C, 86D, and 26E, the new attachment clip 2820 comprises two recesses configured to receive the protrusions 2710. In attaching a sheath 2800 to the osteotome 2800, a user guides the post 2412 of the sheath into the recess 2322 of the osteotome 2700 (as described in great detail above). A user then snaps the new attachment clip 2820 onto the stem 2318. The new attachment clip slides over the protrusions 2710 until the recesses align with the protrusions. At this point the new attachment clip recesses receive the protrusions and the clip clamps onto the sheath. Under an alternative embodiment, the new attachment clip 2820 first snaps over the stem 2318 proximal the protrusions 2710. The sheath and new attachment clip then slide over the protrusions. Under these embodiments, the coupling provides a tensioning which holds the sheath in place. The sheath is dimensioned such that attaching the clip to the stem (using a slide attachment configuration) anchors the post 2412 within the recess 2322 (see Figures 31 and 32). The sheath is immobile as it is held in place by the slide attachment configuration and thereby maintains the location of the post within the recess.

[0209] Figures 28H-28N illustrate the process of attaching the sheath to the osteotome in a slide attachment configuration.

[0210] Under yet another embodiment, a sheath attaches to an osteotome using a inverse slide configuration.

[0211] Figures 33 A-34N illustrate various views of an osteotome 3300 and / or sheath 3400 each configured for inverse slide attachment. As seen in Figures 34A-34N the stem attachment structure (or securing component) and sheath attachment component function in a manner identical to the same configuration set forth above with respect to claims 23A-24N (with the exception that this embodiment does not includes a partial collar feature).

[0212] Under this embodiment, the blade comprises recessed slide stops 3320 on opposing sides of the blade. (See Figures 33A, 33B, 33F). The sheath distal end comprises downwardly projecting wings 3420 disposed on opposing sides of the sheath. (See Figures 34A-34E). Each wing comprises an inwardly projecting post. The inwardly projecting posts create respective slide grooves between the posts and a lower surface of the sheath distal end.

[0213] In attaching a sheath 3700 to the osteotome 3800, a user guides the slide grooves onto the blade until rear walls of the grooves contact the slide stops. A user then attaches the sheath proximal end to the stem. The sheath is immobile as it is held in place by the inverse slide attachment configuration and thereby maintains the location of the sheath with respect to the blade.

[0214] Note that dimensions in schematic figures are in inches.

Claims

CLAIMS1. An apparatus comprising, an osteotome and a sheath, wherein the proximal end of the osteotome comprises a handle, wherein the distal end of the osteotome comprises a blade, wherein an intermediate stem joins the handle and the blade; the proximal end of the sheath comprising an attachment component, wherein a surface of the distal end of the sheath comprises a hollowed region, wherein the hollowed region comprises a stem; the proximal end of the stem comprising a securing component for receiving and securing the attachment component of the sheath; the blade comprising a blade curvature, wherein a surface of the blade curvature comprises a recessed opening; the recessed opening, the stem, the attachment component, and the securing component configured to cooperate in securing the sheath to the blade, wherein the securing comprises inserting the stem into the recessed opening, wherein the securing comprises coupling the attachment component to the securing component.

2. The apparatus of claim 1, wherein the sheath is dimensioned so that the coupling anchors the stem in place within the recessed opening.

3. The apparatus of claim 1, wherein the attachment component comprises an attachment clip.

4. The apparatus of claim 3, wherein the securing component comprises an upper proximal portion of the stem.

5. The apparatus of claim 4, wherein the coupling snaps the attachment clip onto the upper proximal portion of the stem.

6. The apparatus of claim 5, wherein the attachment clip snaps into place adjacent to a partial collar surrounding a proximal lower portion of the sheath.

7. The apparatus of claim 1, wherein the attachment component comprises a receiving hole.

8. The apparatus of claim 7, wherein the securing component comprises a column located on the stem proximate the distal end of the handle.

9. The apparatus of claim 8, wherein the coupling snaps the column into the receiving hole.

10. The apparatus of claim 1, wherein the attachment component comprises a recessed attachment clip, wherein the recessed attachment clip comprises two grooves in opposing inner surfaces of the attachment clip.

11. The apparatus of claim 10, wherein the securing component comprises two tongues extending laterally in opposing directions at a location on the stem proximate the distal end of the handle.

12. The apparatus of claim 11, wherein the coupling comprises snapping the recessed attachment clip and grooves over and onto the tongues such the recessed attachment clip is secured to the stem in a tongue and groove configuration.

13. The apparatus of claim 11, wherein the coupling comprises snapping the recessed attachment clip onto the stem at a location proximate the tongues.

14. The apparatus of claim 13, wherein the coupling comprises sliding the grooves over the tongues to secure the recessed attachment clip to the stem in a tongue and groove configuration.

15. The apparatus of claim 1, wherein the distal end of the sheath comprises a protective blade covering.

16. The apparatus of claim 15, wherein the securing the sheath to the osteotome locates the protective covering over and extending beyond the blade.

17. The apparatus of claim 16, wherein the protective covering comprises an extension layer, wherein the extension layer increases a thickness of the protective covering when it extends beyond a cutting tip of the blade.

18. The apparatus of claim 17, wherein the lower surface of the extension layer follows a trajectory of the blade curvature.

19. An apparatus comprising, an osteotome and a sheath, wherein a proximal end of the osteotome comprises a handle, wherein the distal end of the osteotome comprises a blade, wherein an intermediate stem joins the handle and the blade; the proximal end of the sheath comprising an attachment component, wherein the distal end of the sheath comprises downwardly projecting wings disposed on opposing sides of the sheath, wherein each wing comprises an inwardly projecting post, wherein the inwardly projecting posts create respective slide grooves between the posts and the lower surface of the sheath distal end; the proximal end of the stem comprising a securing component for receiving and securing the attachment component; the blade comprising recessed slide stops disposed on opposing sides of the blade; the slide stops, the downwardly projecting wings, the attachment component, and the securing component configured to cooperate in securing the sheath to the blade, wherein the securing comprises sliding the grooves onto the blade until rear walls of the grooves contact the slide stops.

20. The apparatus of claim 19, wherein the attachment component comprises an attachment clip.21 . The apparatus of claim 20, wherein the securing component comprises an upper proximal portion of the stem.

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