CN111870405B

CN111870405B - External cup and hip joint prosthesis having the same

Info

Publication number: CN111870405B
Application number: CN202010930471.8A
Authority: CN
Inventors: 刘敏
Original assignee: Beijing AK Medical Co Ltd
Current assignee: Beijing AK Medical Co Ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2025-02-11
Anticipated expiration: 2040-09-07
Also published as: CN111870405A

Abstract

The present invention provides an outer cup and a hip joint prosthesis having the same. The outer cup comprises: an outer cup body having a first accommodating cavity and a first opening, the outer cup body being made of a metal material; a stop ring being arranged on the outer side wall of the outer cup body close to the first opening, the stop ring being made of a medical polyethylene material or a plastic material. The technical solution of the present invention can effectively solve the problem in the prior art that the outer cup and the inner liner of the hip joint prosthesis are easily wrapped by soft tissue.

Description

Outer cup and hip joint prosthesis with same

Technical Field

The invention relates to the field of artificial prostheses, in particular to an outer cup and a hip joint prosthesis with the outer cup.

Background

The hip joint prosthesis replacement products are double-acting joint products besides the combination of the joint surface formed between the lining and the ball head and the locking of the lining and the outer cup which are more common. The double-acting hip joint prosthesis comprises two joint surfaces, one joint surface is between the outer cup and the inner liner, and the other joint surface is between the inner liner and the ball head, and the combination mode is beneficial to improving the mobility of the hip joint prosthesis, reducing the abrasion of the hip joint prosthesis and prolonging the service life of the hip joint prosthesis.

The outer cup applied to the double-acting hip joint prosthesis in the market at present has similar appearance to the common outer cup, and is divided into biological type and bone cement type, and the inner surface of the outer cup is designed with high polishing so as to reduce the abrasion between the outer cup and the inner lining. However, after the outer cup is implanted into a patient, soft tissues in the patient are easily wrapped around the edges of the outer cup and the inner liner, which not only affects the mobility of the hip joint prosthesis, but also causes pain to the patient.

Disclosure of Invention

The invention mainly aims to provide an outer cup and a hip joint prosthesis with the outer cup, so as to solve the problem that the outer cup and an inner liner of the hip joint prosthesis in the prior art are easily wrapped by soft tissues.

In order to achieve the above object, according to one aspect of the present invention, there is provided an outer cup including an outer cup body having a first receiving cavity and a first opening, the outer cup body being made of a metal material, and a stopper ring disposed on an outer sidewall of the outer cup body near the first opening, the stopper ring being made of a medical polyethylene material or a plastic material.

Further, the medical polyethylene material can be an ultra-high molecular weight polyethylene material or a high crosslinking polyethylene material, and the plastic material can be a solid medical silicone rubber material or a aliphatic thermoplastic polyurethane elastomer material.

Further, the metal material may be cobalt chromium molybdenum alloy or high nitrogen stainless steel.

Further, the stop ring is detachably arranged on the outer cup body.

Further, the outer cup body is provided with a mounting ring groove, and the stop ring is inserted into the mounting ring groove.

Further, a guide surface is arranged on the mounting ring groove, the stop ring is provided with a stop surface, and the guide surface is positioned on the circumferential outer side of the stop surface.

Further, the installation ring groove comprises a guide groove section and a communicating groove section positioned outside the guide groove section, the groove wall of the guide groove section, which is close to the outside, forms a guide surface, the stop ring comprises a stop ring body and an installation ring arranged on the inner ring of the stop ring body, the installation ring comprises a matching ring section matched with the guide groove section and a connecting ring section matched with the communicating groove section, and the surface of the outer side of the matching ring section forms a stop surface.

Further, the longitudinal section of the mounting ring groove and the longitudinal section of the stop ring are T-shaped.

Further, a first mounting notch penetrating through the mounting ring groove is formed in the outer cup body, and a second mounting notch corresponding to the first mounting notch is formed in the stop ring so that the stop ring is an open loop.

According to another aspect of the invention, a hip joint prosthesis is provided, comprising an outer cup, a lining and a ball head, wherein the outer cup is the outer cup, the lining is movably arranged in a first accommodating cavity of the outer cup, the lining is provided with a second accommodating cavity, and the ball head is movably arranged in the second accommodating cavity.

By applying the technical scheme of the invention, the stop ring is arranged on the outer side wall of the outer cup body, which is close to the first opening, and can stop soft tissues of a patient, so that the outer cup is prevented from being wrapped by gradually growing soft tissues after being installed, the mobility of the hip joint prosthesis is better, and pain of the patient can be avoided. The stop ring is made of polyethylene material or plastic material, so that the stop ring can be made into a proper shape according to the outline of soft tissues, and a better stop effect is achieved. In addition, the outer cup body is made of metal materials, so that the outer cup has better wear resistance, and the service life of the hip joint prosthesis can be prolonged.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

Fig. 1 shows a schematic perspective view of an embodiment of an outer cup according to the invention;

FIG. 2 shows an enlarged schematic view of the structure at A of the outer cup of FIG. 1;

FIG. 3 illustrates a bottom view of the outer cup of FIG. 1;

FIG. 4 shows a schematic cross-sectional view in the B-B direction of the outer cup of FIG. 3;

FIG. 5 shows an enlarged schematic view of the structure at C of the outer cup of FIG. 4;

FIG. 6 shows a schematic perspective view of the stop ring of the outer cup of FIG. 1;

FIG. 7 shows an enlarged schematic view of the stop ring of FIG. 6 at D;

FIG. 8 is a schematic perspective view showing the stop ring of the outer cup of FIG. 1 when not connected to the outer cup body;

FIG. 9 shows an enlarged schematic view of the outer cup of FIG. 8 at E;

FIG. 10 shows a schematic longitudinal section of the outer cup of FIG. 8, and

Fig. 11 shows an enlarged schematic view of the structure at F of the outer cup of fig. 10.

Wherein the above figures include the following reference numerals:

1. The first accommodating cavity, 2, a first opening, 3, a mounting hole, 10, an outer cup body, 20, a stop ring, 21, a stop ring body, 22, a mounting ring, 221, a matching ring section, 222, a connecting ring section, 23, a stop surface, 30, a mounting ring groove, 31, a guide groove section, 32, a communicating groove section, 33, a guide surface, 40, a first mounting notch, 50, a second mounting notch, 60, a wing plate, 70, a shell, 71, a second opening, 72, a side plate, 73, a front plate, 74, a rear plate, 75, a bottom plate, 76, a stop side plate, 80, a bracket, 81, a bonding surface, 90 and a sizing sleeve.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

As shown in fig. 1 and 3, the outer cup of the present embodiment includes an outer cup body 10 and a stopper ring 20. The outer cup body 10 is provided with a first accommodating cavity 1 and a first opening 2, the outer cup body 10 is made of a metal material, and a stop ring 20 is arranged on the outer side wall of the outer cup body 10 near the first opening 2, and the stop ring 20 is made of a medical polyethylene material or a plastic material.

By applying the technical scheme of the embodiment, the stop ring 20 is arranged on the outer side wall of the outer cup body 10, which is close to the first opening 2, and the stop ring 20 can stop soft tissues of a patient, so that the soft tissues are prevented from growing continuously towards the gap between the outer cup and the inner liner, the mobility of the hip joint prosthesis is better, and pain of the patient can be avoided. Since the stopper ring 20 is made of a polyethylene material or a plastic material, the stopper ring 20 can be formed in a proper shape according to the contour of soft tissues, thereby achieving a better stopping effect. In addition, the outer cup body 10 is made of a metal material, so that the outer cup has better wear resistance, thereby enabling the service life of the hip joint prosthesis to be prolonged.

As shown in fig. 1, in the present embodiment, the medical polyethylene material may be an ultra-high molecular weight polyethylene material or a highly crosslinked polyethylene material, and the plastic material may be a solid medical silicone rubber material or a aliphatic thermoplastic polyurethane elastomer material. In the above structure, the ultra-high molecular weight polyethylene material or the high crosslinking polyethylene material may be trimmed to an appropriate shape according to the contour of the soft tissue of the patient. The solid medical silicon rubber material has high elasticity, is easy to shape, can stretch at any amplitude at any position according to the soft tissue wrapping condition in operation, and is convenient to operate. The shape of the aliphatic thermoplastic polyurethane elastomer material can be fixed by plastic deformation and keeping the shape at normal temperature under the condition that the temperature is increased to a preset temperature value, so that the temperature of the aliphatic thermoplastic polyurethane elastomer material can reach the preset temperature in operation, and the aliphatic thermoplastic polyurethane elastomer material can be restored to the normal temperature after being stretched to a proper shape according to the outline of soft tissues of a patient. The above structure can enable the stopper ring 20 to exert a better stopper effect on the soft tissue of the patient.

As shown in fig. 1, in the present embodiment, the metal material may be cobalt-chromium-molybdenum alloy or high nitrogen stainless steel. In the structure, the cobalt-chromium-molybdenum alloy has better wear resistance and corrosion resistance, so that the wear resistance of the outer cup is better, and the service life of the outer cup is prolonged. The high nitrogen stainless steel has better strength, ductility and corrosion resistance, thereby facilitating the processing of the outer cup body 10 and improving the service life of the outer cup.

As shown in fig. 1, 6 and 8, in the present embodiment, the stopper ring 20 is detachably provided on the outer cup body 10. In the above structure, when the stopper ring 20 is damaged, the stopper ring 20 can be detached from the outer cup body 10 to be replaced, thereby avoiding replacement of the whole hip joint prosthesis and saving the operation cost of the user.

As shown in fig. 1 and 2, in the present embodiment, the outer cup body 10 is provided with a mounting groove 30, and the stopper ring 20 is inserted into the mounting groove 30. The above structure is simple, and the stopper ring 20 is easily coupled to the outer cup body 10.

As shown in fig. 1,2, 5 and 7, in the present embodiment, a guide surface 33 is provided on the mounting ring groove 30, the stopper ring 20 has a stopper surface 23, and the guide surface 33 is located circumferentially outward of the stopper surface 23. In the above structure, the guide surface 33 can stop the stop ring 20 during the process of penetrating the stop ring 20 into the installation ring groove 30, so that the stop ring 20 can move forward along the installation ring groove 30, and the stop ring 20 is prevented from penetrating out of the installation ring groove 30 during the installation process. In addition, after the stopper ring 20 penetrates into the installation ring groove 30, the guide surface 33 is located at the circumferential outer side of the stopper surface 23, and when the stopper ring 20 has a tendency to come out from the installation ring groove 30, the guide surface 33 can stop the stopper ring 20, thereby preventing the stopper ring 20 from coming out from the installation ring groove 30.

As shown in fig. 1, 2, 5 and 7, in the present embodiment, the installation ring groove 30 includes a guide groove section 31 and a communication groove section 32 located outside the guide groove section 31, the groove wall of the guide groove section 31 near the outside forms a guide surface 33, the stopper ring 20 includes a stopper ring body 21 and an installation ring 22 provided at the inner ring of the stopper ring body 21, the installation ring 22 includes a mating ring section 221 mated with the guide groove section 31 and a connection ring section 222 mated with the communication groove section 32, and the surface of the outer side of the mating ring section 221 forms a stopper surface 23. In the above-described structure, the mounting ring 22 can be inserted into the mounting ring groove 30, and the stopper ring body 21 can be extended outward from the mounting ring groove 30 to the circumferential outside of the first opening 2, thereby forming a stopper for soft tissues. Specifically, the mating ring segment 221 of the mounting ring 22 can extend into the guide groove segment 31 of the mounting ring groove 30, and the connecting ring segment 222 of the mounting ring 22 can extend into the communication groove segment 32 of the mounting ring groove 30. The outer surface of the mating ring segment 221 forms a stop surface 23, which stop surface 23 can be stopped by the guide surface 33 when the stop ring 20 has a tendency to come out of the mounting ring groove 30, thereby preventing the stop ring 20 from coming out of the mounting ring groove 30. The above structure enables the stopper ring 20 to be stably coupled in the mounting groove 30.

As shown in fig. 2 and 4 to 7, in the present embodiment, the vertical section of the mounting groove 30 and the vertical section of the stopper ring 20 are T-shaped. In the above structure, the longitudinal section of the stopper ring 20 is fitted with the longitudinal section of the installation groove 30, thereby facilitating penetration of the stopper ring 20 into the installation groove 30. In addition, the T-shaped longitudinal section provides a better guiding effect of the guiding surface 33 on the stop surface 23, thereby further enabling the stop ring 20 to be stably connected in the mounting ring groove 30.

As shown in fig. 1 to 3, 6 and 7, in the present embodiment, a first mounting notch 40 penetrating through the mounting groove 30 is provided on the outer cup body 10, and a second mounting notch 50 corresponding to the first mounting notch 40 is provided on the stopper ring 20 so that the stopper ring 20 is open-loop. In the above-described structure, the first mounting notch 40 is provided so that the mounting groove 30 can be exposed to two opposite longitudinal sections, and the second mounting notch 50 corresponding to the first mounting notch 40 is provided on the stopper ring 20 so that the stopper ring 20 has a first end and a second end. When the stopper ring is mounted, the T-shaped cross section of the first end of the stopper ring 20 is opposite to the T-shaped cross section of one of the longitudinal sections of the mounting groove 30, and then an external force is applied to the stopper ring 20 such that the first end of the stopper ring 20 protrudes into the mounting groove 30. The external force is continuously applied to the stopper ring 20 such that the first end of the stopper ring 20 moves toward the longitudinal section of the other installation groove 30 until the first end of the stopper ring 20 moves to the longitudinal section of the installation groove 30. The above-mentioned simple structure, the resistance that the user received when installing stop ring 20 is less to make stop ring 20 can connect in installation annular groove 30 fast, promoted the assembly rate of outer cup.

As shown in fig. 1,3 and 8, the outer cup of the present embodiment includes an outer cup body 10 and a wing plate 60. The wing plate 60 is disposed on the outer sidewall of the outer cup body 10, the wing plate 60 includes a housing 70 and a bracket 80 disposed in the housing 70, the elastic modulus of the bracket 80 is smaller than that of the housing 70, and the wing plate 60 is provided with a mounting hole 3.

By applying the technical solution of the present embodiment, since the elastic modulus of the support 80 is smaller than that of the housing 70, the support 80 is more likely to bend relative to the housing 70. The support 80 is arranged in the wing plate 60, so that the specific gravity of the material with large elastic modulus in the wing plate 60 can be reduced, the whole wing plate 60 is easier to bend, the wing plate 60 is easier to attach to the bone of a patient, the outer cup can be better fixed to the bone, and the stability of the hip joint prosthesis on the bone is improved.

The term "elastic modulus" as used herein refers to the stress in the unidirectional stress state divided by the strain in that direction. The elastic modulus can be regarded as an index for measuring the difficulty of elastic deformation of the material, and the larger the value is, the larger the stress for causing the material to generate certain elastic deformation is, namely the larger the rigidity of the material is.

As shown in fig. 8, in the present embodiment, the housing 70 is made of cobalt chrome molybdenum material or high nitrogen stainless steel material, and the bracket 80 is made of plastic material. In the structure, the cobalt-chromium-molybdenum alloy has better wear resistance and corrosion resistance, so that the wing plate is not easy to damage and has longer service life. The high nitrogen stainless steel has better strength, ductility and corrosion resistance, thereby facilitating the processing of the outer cup body 10 and improving the service life of the outer cup. The lower modulus of elasticity of the plastic material makes the flap 60 as a whole more pliable. The structure can prolong the service life of the wing plate 60, and can lead the wing plate 60 to be easier to bend and have better fixing effect, thereby delaying the repairing time, reducing the repairing times and relieving the pain of patients.

Because the wing plate 60 forms a contact surface with the bone of the patient after bending, if the shell 70 with a harder texture is contacted with the bone, the shell 70 and the bone are difficult to be well attached, the fusion of the outer cup body 10 and the bone of the patient is not easy, and the use stability of the prosthesis after installation is poor. As shown in fig. 8, 9 and 11, in the present embodiment, the bracket 80 has a bonding surface 81 to be bonded to the bone, and the housing 70 is provided with a second opening 71 to avoid the bonding surface 81. In the above-mentioned structure, the pterygoid lamina 60 is after buckling, and the faying surface 81 of support 80 can be with patient's bone surface contact, because support 80 is plastic material to make the contour adaptation on faying surface 81 and patient's bone surface, the autologous bone of patient of being convenient for grow into on the pterygoid lamina 60, thereby make outer cup body 10 and the better that patient's own bone can fuse, make the prosthesis have better stability in use.

As shown in fig. 8, 9 and 11, in this embodiment, an osteoinductive small molecule is provided on the bonding surface 81. In the above structure, the autologous bone of the patient can be extracted as the osteogenic material to be added onto the joint surface 81 of the support 80 during or before the operation, and the osteogenic material can be transferred onto the support 80 by the osteoinductive molecules and combined with the support 80, so as to provide living cell population for the support 80, thereby realizing the fusion of the wing plate and the autologous bone of the patient, and further enabling the prosthesis to have better use stability.

As shown in fig. 8, in the present embodiment, the holder 80 is inserted into the housing 70 through the second opening 71. The above-described structure is simple, and facilitates the rate of assembly of the bracket 80 with the housing 70.

As shown in fig. 8, 9 and 11, in the present embodiment, the housing 70 includes two side plates 72 disposed opposite to each other, a front plate 73 and a rear plate 74 disposed on both sides of the two side plates 72, a bottom plate 75 disposed below the side plates 72, the front plate 73 and the rear plate 74, and a stopper side plate 76 disposed on upper edges of the two side plates 72 and upper edges of the rear plate 74, an upper surface of the front plate 73 is lower than an upper surface of the side plates 72, and a mouth portion enclosed between the upper surface of the front plate 73 and an inner side edge of the stopper side plate 76 forms the second opening 71. In the above-described structure, the bottom plate 75 and the stopper side plate 76 can limit the side plates 72, the front plate 73, and the rear plate 74 of the bracket 80 in the up-down direction, and can enclose the bracket 80, thereby limiting the bracket 80. When the wing plate 60 is bent, the abutting surface 81 of the bracket 80 can be abutted with the bone surface of the patient through the second opening 71, and the stopping edge plate 76 can stop the bracket 80 at this time, so that the bracket 80 is prevented from being separated from the housing 70. The above structure enables the holder 80 to be stably coupled within the housing 70, thereby enabling the outer cup to have better stability in use.

As shown in fig. 8, 9 and 11, in the present embodiment, the outer cup body 10 and the outer shell 70 are integrally formed. The structure can ensure the connection strength of the wing plate and the outer cup body 10, so that the wing plate is not easy to damage when being bent. In addition, the outer cup body 10 and the outer shell 70 are made of the same material, and are made of cobalt chromium molybdenum materials or high-nitrogen stainless steel materials, so that the outer cup body 10 is better in wear resistance and corrosion resistance.

The mounting hole 3 of the mounting screw is required to be arranged on the wing plate 60 to be fixed with the autologous bone of the patient, and the wing plate 60 comprises a bracket made of plastic materials, so that the mounting hole 3 in the bracket 80 is easy to deform when the wing plate is bent, and the screw is difficult to penetrate into the mounting hole 3, thereby bringing inconvenience to the fixation of the outer cup body 10. In order to solve the above problems, as shown in fig. 8 to 11, in the present embodiment, the outer cup further includes a shaping sleeve 90 penetrating into the mounting hole 3 and having an interference fit with the mounting hole 3, and the elastic modulus of the shaping sleeve 90 is greater than that of the support 80. In the above structure, the setting sleeve 90 is disposed in the mounting hole 3, and the elastic modulus of the setting sleeve 90 is greater than that of the bracket 80, so that the setting sleeve 90 is not easy to deform when the wing plate 60 is bent. When the screw is attached, the screw is attached to the patient's autogenous bone through the through-hole in the sizing sleeve 90, thereby facilitating the fixation of the outer cup body 10.

In this embodiment, as shown in fig. 11, the number of the mounting holes 3 is plural, and the number of the setting sleeves 90 is plural and is arranged in one-to-one correspondence with the mounting holes 3, and in the above structure, the outer cup body 10 is connected to the autologous bone of the patient by passing through the through holes in the setting sleeves 90 when the screws are connected. The above structure is provided with a plurality of mounting holes 3, so that the connection point position of the outer cup body 10 and the autologous bone can be increased, and the connection between the outer cup body 10 and the autologous bone of a patient is more stable.

As shown in fig. 9 and 11, in the present embodiment, the sizing sleeve 90 is made of a titanium alloy material, a cobalt chromium molybdenum material, or a high nitrogen stainless steel material. The above structure makes the shaping sleeve 90 have a larger elastic modulus, so that the shaping sleeve 90 is not easy to deform when the wing plate 60 is bent. In addition, the wear resistance and corrosion resistance of the sizing sleeve 90 can be improved by the materials, so that the service life of the sizing sleeve 90 is prolonged, and the service life of the whole outer cup is prolonged.

The application also provides a hip joint prosthesis, and an embodiment of the hip joint prosthesis comprises an outer cup, an inner liner and a ball head. The outer cup is the outer cup, the inner liner is movably arranged in the first accommodating cavity 1 of the outer cup, the inner liner is provided with a second accommodating cavity, and the ball head is movably arranged in the second accommodating cavity. In the structure, the ball head can move in the second accommodating cavity of the inner liner, and the inner liner can move in the first accommodating cavity 1 of the outer cup, so that the flexibility of the hip joint prosthesis is better. The hip prosthesis with the outer cup has the above-mentioned advantages, since the outer cup has the advantage of blocking soft tissue extending below the first opening 2. Because the outer cup can prevent soft tissues from extending to the lower side of the first opening 2, gaps between the outer cup and the inner liner can be prevented from being wrapped by the soft tissues, so that the mobility of the hip joint prosthesis is better, and pain of a patient is avoided.

In this embodiment, the outer cup has the advantage that the wing plate is easy to bend, so the hip joint prosthesis with the outer cup also has the advantages.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An outer cup, comprising:

An outer cup body (10) having a first accommodation cavity (1) and a first opening (2), the outer cup body (10) being made of a metallic material;

A stop ring (20) arranged on the outer side wall of the outer cup body (10) close to the first opening (2), wherein the stop ring (20) is made of medical polyethylene material or plastic material;

the outer cup body (10) is provided with a mounting ring groove (30), and the stop ring (20) is inserted into the mounting ring groove (30);

The mounting ring groove (30) is provided with a guide surface (33), the stop ring (20) is provided with a stop surface (23), and the guide surface (33) is positioned on the outer side of the stop surface (23) in the circumferential direction;

The mounting ring groove (30) comprises a guide groove section (31) and a communication groove section (32) positioned on the outer side of the guide groove section (31), the groove wall, close to the outer side, of the guide groove section (31) forms the guide surface (33), the stop ring (20) comprises a stop ring body (21) and a mounting ring (22) arranged on the inner ring of the stop ring body (21), the mounting ring (22) comprises a matching ring section (221) matched with the guide groove section (31) and a connecting ring section (222) matched with the communication groove section (32), and the surface on the outer side of the matching ring section (221) forms the stop surface (23);

The outer cup is characterized in that a first mounting notch (40) penetrating through the mounting ring groove (30) is formed in the outer cup body (10), and a second mounting notch (50) corresponding to the first mounting notch (40) is formed in the stop ring (20) so that the stop ring (20) is an open loop.

2. The cup according to claim 1, wherein the medical polyethylene material is an ultra high molecular weight polyethylene material or a highly crosslinked polyethylene material, and the plastic material is a solid medical silicone rubber material or a aliphatic thermoplastic polyurethane elastomer material.

3. The outer cup of claim 1, wherein the metallic material is cobalt chrome molybdenum alloy or high nitrogen stainless steel.

4. The outer cup as claimed in claim 1, characterized in that the stop ring (20) is detachably arranged on the outer cup body (10).

5. The outer cup as claimed in claim 1, characterized in that the mounting groove (30) and the stop ring (20) are T-shaped in longitudinal section.

6. A hip joint prosthesis comprising:

An outer cup, characterized in that it is an outer cup according to any one of claims 1 to 5;

A liner movably arranged in the first accommodating cavity (1) of the outer cup, wherein the liner is provided with a second accommodating cavity;

the ball head is movably arranged in the second accommodating cavity.