DE102005001256B3 - Shoulder joint endoprosthesis comprises a ball-and-socket joint with a convex part having divergent holes forming an opening through which fixing screws can be inserted into the scapula - Google Patents

Abstract

Shoulder joint endoprosthesis comprises a shaft (2) for anchoring in the medullary canal of the humerus, a middle part (10) that can be releasably attached to the shaft, and a convex part (15) that can be anchored in the scapula and cooperates with a sliding surface (14) of the middle part to form a ball-and-socket joint. The convex part has several divergent holes (18) forming an opening through which fixing screws can be inserted into the scapula.

Description

The The invention is based on a glenoid component for a shoulder joint endoprosthesis endoprosthetic care of the human or animal shoulder joint according to the preamble of claim 1.

For example is a shoulder joint endoprosthesis known from WO 01/47442 A1, which has a glenoides primitive having a plate with a central mounting block and anchoring for fixation in a glenoid excavation comprises and a glenoid ball which is placed on the glenoid element becomes. This has an axial screw which is screwed into a pin is, as well as a molded surface that designed so that they glide in a shell of an upper arm component of the shoulder joint endoprosthesis can. The device comprises components that attach the glenoid ball to the glenoid element to simplify. For this purpose, a pen is provided which in the glenoid element and in an axial passage the screw introduced becomes. This will guide the glenoid ball by placing it on the pin threaded becomes. The free end of the screw can also be at an angle, to thread to facilitate.

adversely to the inverse shoulder joint endoprosthesis known from WO 01/47442 A1 is in particular that the Glenoid element is multipart and the attachment of the glenoid Basic element on the scapula and the glenoid ball on the glenoid Basic element is complicated and thus tedious, which is e.g. negatively affects the duration of surgery.

task Accordingly, it is an object of the present invention to provide a one-piece glenoid component. in a simple way and yet securely fastened to the scapula is.

The The object is achieved by the characterizing features of claim 1 solved in connection with the generic features.

advantageously, are provided in the glenoid component a plurality of bores, which in a sliding surface the glenoid component at least form an opening which through appropriate additional measures for the Assembly, for example by means of fixing screws, with which the Glenoid component is fixed to the scapula, easy to install can be designed.

Further advantageous embodiments of the invention are specified in the subclaims.

embodiments The invention will be described below with reference to schematic representations closer in the drawing explained. In the drawing show:

1A C is a side view, a perspective view and a sectional view of the components of a first exemplary embodiment of a shoulder joint endoprosthesis configured according to the invention,

2A -E various views and sections of the glenoid component of the first embodiment of an inventively designed shoulder joint endoprosthesis according to 1A -C,

3A -E various views and sections of the glenoid component of a second embodiment of an inventively designed shoulder joint endoprosthesis in the same representation as 2A -E, and

4A -E various views and sections of the glenoid component of a third embodiment of an inventively designed shoulder joint endoprosthesis in the same representation as 2A -E and 3A -E.

1A to 1C shows in various views, the components of a first embodiment of an inventively designed shoulder joint endoprosthesis 1 in unmounted condition. The inventively designed shoulder joint endoprosthesis 1 includes a shaft 2 , which is used in a preparatory to resect, not further shown humerus or humerus. The shaft 2 is designed so that it can be caulked or cemented in a medullary cavity of the humerus (Oberarmdiaphyse). The shaft 2 can thereby longitudinal ribs 3 in order to achieve an optimal fastening and anti-rotation in the medullary cavity.

At its proximal end, the shaft 2 a radially expanded area 4 on which hollow cylindrical with a recess 5 trained and with slots 6 is provided over the circumference of the radially expanded area 4 are arranged distributed. In the recess 5 is a twistable insert 7 used, which with a thread 8a in a corresponding thread 8b of the radially expanded area 4 intervenes. A cross-section wedge-shaped ring insert 9 transmits at axial rotation of the insert 7 by a suitable tool an expanding force on the radially expanded Area 4 so that the scope of the area 4 is further increased in the radial direction. As a result, the radially widened area spreads 4 in one on the shaft 2 attachable and on the radially expanded area 4 movable middle part 10 ,

The middle part 10 is preferably cranked relative to a longitudinal axis 11 of the shaft 2 educated. It has a recess 12 on which the reception of the radially widened area 4 of the shaft 2 serves. The recess 12 sets in the proximal direction with a reduced diameter as a mounting hole 13 continued. Through the mounting hole 13 becomes the tool for twisting the insert 7 for spreading the components shaft 2 and middle part 10 introduced.

Furthermore, the middle part 10 a cup-shaped sliding surface 14 on, which is formed, for example, part-spherical. The sliding surface 14 acts with a glenoid component 15 together, which also part spherical with identical or at least similar radius of curvature as the sliding surface 14 is trained. The glenoid component 15 includes at least one pin 16 for anchoring in the scapula (Scapula).

The problem of shoulder joint endoprostheses 1 is the low coverage of the joint ball through the socket. This creates a complicated situation for the restoration of the joint situation either after a fracture or for the prosthetic restoration of a joint damaged by osteoarthritis. In particular, massive defects in the rotator cuff (so-called rotator cuff insufficiency) are associated with functional loss. The function of the joint is mainly maintained only by the delta muscle. The known inversion of joint ball and socket to prevent immobility fixes this problem relatively efficiently, as this moves the pivot point of the joint to the medial, the lever arm extended and the torque is increased. This leads to a significant mobility improvement.

A disadvantage of known inverse shoulder joint endoprostheses 1 However, this is the problem of fixing the glenoid component 15 on the scapula bone (scapula). The correct positioning and attachment is essential, but extremely expensive for the surgeon, as for example in a two-part design of the glenoid component 15 According to the prior art, additional operation steps are necessary, which represent an additional source of error and which prolongs the duration of the operation. Will the glenoid component 15 incorrectly positioned, there are cases of damage in the shoulder joint endoprosthesis 1 To fear loss of mobility and pain in the patient.

The glenoid component 15 Therefore, according to the invention has several holes 18 on which at different angles relative to a longitudinal axis 19 the glenoid component 15 be introduced into this and the introduction of fasteners such as screws, nails, pins, etc., not shown serve. The holes 18 form at least one opening 21 in a sliding surface 23 the glenoid component 15 , The positioning of the glenoid component 15 in the scapula, on the one hand, it can be more precise and, on the other hand, faster and easier.

2A to 2E shows in various views and sectional views along different levels, a first embodiment of a glenoid component designed according to the invention 15 according to 1A to 1C ,

The glenoid component 15 is, as already described above, at least in the sliding surface 23 partially spherical and can with a pin 16 be anchored in the scapula, but this is not absolutely necessary.

In the glenoid component 15 are in the in 1 and 2 illustrated first embodiment two holes 18 and a central hole 20 in the cone 16 intended. The holes 18 and 20 are especially on the exterior views according to the 2A . 2 B and 2E recognizable.

From the sectional views according to 2C and 2D goes the location of the holes 18 and 20 relative to each other. In a first sectional view along the in 2A With IIC-IIC cut line is seen that the holes 18 as well as the central bore 20 arranged in a plane. In a further sectional view according to 2D along the in 2C IID-IID marked cut line are the three holes 18 . 20 recognizable. The central hole 20 runs parallel to a through the pin 16 extending longitudinal axis 19 the glenoid component 15 while in the embodiment two holes 18 at an angle α to the central bore 20 tilted in the glenoid component 15 are formed.

The holes 18 open sliding surface side in the illustrated embodiment in a common opening 21 from, which is formed slot-like or eight-shaped in the embodiment. This is due to the common mouth of the two holes 18 conditionally, which do not completely overlap in cross section, as axes 22 drilling 18 not on, but below the sliding surface 23 the glenoid component 15 to cut. Also an arrangement of the holes 18 with one at or above the sliding surface 23 lying intersection is conceivable. The shape of the opening 21 allows better accessibility of the holes 18 for introducing the fixation screws, not shown. The opening 21 may additionally be chamfered to improve accessibility and lubricity of the glenoid component 15 in the sliding surface 14 of the middle section 10 the shoulder joint endoprosthesis 1 not to interfere.

The holes 18 and the central hole 20 have a stepped cross section with a shoulder 24 on which the force is introduced into the glenoid component 15 for example, by a screw head of the fixing screw.

3A to 3E shows in various views and sectional views along different levels, a second embodiment of a glenoid component designed according to the invention 15 in the same representation as the 2A to 2E ,

While in the in 2A to 2E illustrated first embodiment of an inventively designed glenoid component 15 two holes 18 and a central hole 20 are provided are in the second embodiment according to 3A to 3E four holes 18 and a central hole 20 intended. The holes are doing as out 3A can be seen in the exemplary embodiment at uniform angular intervals of about 90 ° over the glenoid component 15 arranged distributed. However, other arrangements are conceivable and possible, for example if the shape of the shoulder blade makes this necessary.

According to the number of holes 18 is the opening 21 in the sliding surface 23 the glenoid component 15 designed in the embodiment in the form of two intersecting eight shapes or slots.

The axes 22 drilling 18 are in the 3C and 3D inclined at angles α and β against each other. The angles .alpha. And .beta. Can also be identical, for example, in one sectional plane and also in the sectional plane rotated by 90.degree., But have different angles to that angle of the other sectional plane. It is also conceivable that the angles α and β assume different values in each spatial direction, as required by the anatomical conditions, so that, for example, four holes 18 also four different angles to the longitudinal axis 19 available.

The holes 18 and the central hole 20 also have a stepped cross-section with a shoulder 24 for the introduction of force. The opening 21 is chamfered as in the first embodiment.

The number of holes 18 can also be three or more than four, accordingly, the considerations apply to different or equal angles in the different cutting planes.

4A to 4E shows in various views and sectional views along different levels, a second embodiment of a glenoid component designed according to the invention 15 in the same representation as the 2A to 2E respectively. 3A to 3E ,

In contrast to the two embodiments described above, that in the 4A to 4E described embodiment holes 18 on which are neither with each other nor with the central hole 20 cut, ie skewed into the glenoid component 15 are introduced. The number of holes 18 is two, but it can be more.

The shape of the holes 18 with the shoulder 24 for the introduction of force and the chamfered shape of the opening 21 can be designed as in the embodiments described above. The holes 18 are opposite the longitudinal axis 19 the glenoid component 15 also inclined at any angle α.

The glenoid component 15 exists regardless of the number of holes 18 preferably made of a cobalt-chromium alloy (CoCr), which forms a very smooth, resistant surface and therefore excellent sliding properties on a, for example, polyetheretherketone (PEEK) or a likewise made of CoCr sliding surface 14 of the middle section 10 the shoulder joint endoprosthesis 1 has. Likewise, the glenoid component 15 itself also be made of PEEK, whereby a homogeneous sliding pairing together with the PEEK sliding surface 14 of the middle section 10 is formed.

The shoulder joint endoprosthesis 1 may have other features which serve to improve handling and reliability. For example, a vent hole 17 in the shaft 2 distally below the radially broadened area 4 be formed, through which the recess 5 can be vented. As a result, wound secretions, blood, etc. can be spread during the spreading of the components by screwing in the insert 7 from the recess 5 be derived so that no overpressure arises.

Claims (21)

Shoulder joint endoprosthesis ( 1 ), comprising a shaft which can be anchored in a medullary cavity of a humerus ( 2 ), one with the shaft ( 2 ) detachably connectable central part ( 10 ) with a sliding surface ( 14 ) and one with the sliding surface ( 14 ) glenoid component which cooperates with a spherical joint connection and can be anchored in a shoulder blade bone (US Pat. 15 ), wherein in the glenoid component ( 15 ) several holes ( 18 ) are provided whose longitudinal axes ( 22 ) are inclined towards each other, characterized in that the holes ( 18 ) at least one opening ( 21 ) in a sliding surface ( 23 ) of the glenoid component ( 15 ), through which fixing screws in the scapular bone can be introduced. Shoulder joint endoprosthesis according to claim 1, characterized in that the bores ( 18 ) mutually and / or with a central bore ( 20 ) of the glenoid component ( 15 ). Shoulder joint endoprosthesis according to claim 1 or 2, characterized in that the opening ( 21 ) in the sliding surface ( 23 ) of the glenoid component ( 15 ) through the drilled holes ( 18 ) is formed. Shoulder joint endoprosthesis according to claim 3, characterized in that the opening ( 21 ) has a shape deviating from a circular shape, which depends on the number of holes ( 18 ) is dependent. Shoulder joint endoprosthesis according to claim 4, characterized in that the opening ( 21 ) with two holes ( 18 ) has a slot or octagonal shape. Shoulder joint endoprosthesis according to claim 4, characterized in that the opening ( 21 ) at three holes ( 18 ) has a cloverleaf-like shape. Shoulder joint endoprosthesis according to claim 4, characterized in that the opening ( 21 ) at four holes ( 18 ) has a shape of two crossed eight shapes. Shoulder joint endoprosthesis according to claim 1, characterized in that by a skewed arrangement of the holes ( 18 ) several openings ( 21 ) in the sliding surface ( 23 ) of the glenoid component are formed. Shoulder joint endoprosthesis according to one of claims 1 to 8, characterized in that the at least one opening ( 21 ) is chamfered. Shoulder joint endoprosthesis according to one of claims 1 to 9, characterized in that the number of bores ( 18 ) is two or more. Shoulder joint endoprosthesis according to one of claims 1 to 10, characterized in that longitudinal axes ( 22 ) of the holes ( 18 ) at an angle (α, β) with respect to a longitudinal axis ( 19 ) of the glenoid component ( 15 ) are inclined. Shoulder joint endoprosthesis according to claim 11, characterized characterized in that Angle (α, β) in all Cutting planes are the same size. Shoulder joint endoprosthesis according to claim 11, characterized in that the angles (α) of at least one cutting plane through the glenoid component ( 15 ) are the same size and different from the angle (β) of further cutting planes. Shoulder joint endoprosthesis according to claim 11, characterized characterized in that Angle (α, β) within all cutting planes are different in size. Shoulder joint endoprosthesis according to one of Claims 11 to 14, characterized in that the longitudinal axes ( 22 ) of the holes ( 18 ) with each other and / or with the longitudinal axis ( 19 ) of the glenoid component ( 15 ) on or outside the sliding surface ( 23 ) of the glenoid component ( 15 ) to cut. Shoulder joint endoprosthesis according to one of Claims 1 to 15, characterized in that the bores ( 18 ) stepped with an annular shoulder ( 24 ) are formed. Shoulder joint endoprosthesis according to claim 16, characterized in that over the shoulder ( 24 ) a force introduction into the glenoid component ( 15 ) he follows. Shoulder joint endoprosthesis according to one of claims 1 to 17, characterized in that the sliding surface ( 14 ) of the middle part ( 10 ) is made of a cobalt-chromium alloy (CoCr) or polyetheretherketone (PEEK). Shoulder joint endoprosthesis according to one of Claims 1 to 18, characterized in that the glenoid component ( 15 ) is made of a cobalt-chromium alloy (CoCr) or polyetheretherketone (PEEK). Shoulder joint endoprosthesis according to one of Claims 1 to 19, characterized in that the glenoid component ( 15 ) a pin ( 16 ) having. Shoulder joint endoprosthesis according to one of Claims 1 to 20, characterized in that the glenoid component ( 15 ) with the pin ( 16 ) and into the holes ( 18 ) insertable screws or nails is anchored in the scapular bone.