Patella holding device

Abstract

To provide a patella holding device (10) for holding a patella in a holding plane.SOLUTION: The patella holding device includes two gripping elements (12, 14) connected to each other via a chain (16) including chain links (18, 20). The adjacent ones of the chain links are movable relatively to each other around a rotation axis (24) perpendicular to the holding plane.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a patella retaining device according to US 2006 / 0161165 A1 for retaining the patella in a retaining plane. [Background technology]

[0002] As part of a total knee replacement or total knee arthroplasty ("TKA") surgery, a posterior portion of the patella may be resected in order to implant a patella component. The step of resecting the patella requires the use of a patella retaining device to hold or hold the patella during cutting. US 2006 / 0161165 A1 proposes providing a pliers-type structure having two mutually movable handle portions, one of which is connected to a first clamp portion that engages the skin / subcutaneous tissue overlying the anterior portion of the patella, and the other of which is connected to a second clamp portion that engages the posterior portion of the patella, thereby providing a clamping action along the anterior-posterior axis of the patella. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE PRESENT EMBODIMENTS One object of the present invention is to provide a patella retention device that provides secure retention of the patella and is comfortable for the surgeon to handle.

[0004] This object is solved by a patella retainer having the features of claim 1. Preferred embodiments are defined in the dependent claims. [Means for solving the problem]

[0005] According to the invention, the patella retainer comprises two gripping elements connected to each other via a chain, the chain comprising chain links, adjacent chain links being movable relative to each other about an axis of rotation perpendicular to the retaining plane.

[0006] The chain element provides a flexible structure to encircle the holding area of ​​the patella. This flexibility ensures a secure fit between the patella holder and the patella, regardless of the size or shape of the patella. At the same time, the chain element provides an interlocking of the two gripping elements that allows for comfortable handling by the surgeon.

[0007] According to a preferred embodiment, the retaining plane is parallel to or coincides with the plane defined by the medial-lateral axis and the proximal-distal axis of the patella. In particular, the retaining plane is parallel to or coincides with the resection plane of the patella. The chain elements surrounding the retaining area of ​​the patella are arranged in the retaining plane and can be arranged such that the two gripping elements are arranged adjacent to each other. The gripping elements can be arranged at any angular position in the retaining plane. For example, the gripping elements can be arranged proximally, laterally, distally or medially on the patella, as well as at any angular intermediate position, depending on the surgeon's preference. Furthermore, the surgeon can use the patella retaining device in a first orientation relative to the retaining plane, or in an opposite orientation relative to the retaining plane.

[0008] In one embodiment, the chain comprises at least 8 pivot axes, preferably at least 12 pivot axes, in particular at least 16. The more pivot axes there are, the more snug the chain can be fitted around the circumference of the patella retention area.

[0009] In one embodiment, the chain has a maximum of 20 pivots, limiting the number of parts that must be assembled during manufacture and cleaned after use.

[0010] In one embodiment, the chain links include chain links configured as outer links and chain links configured as inner links, with the outer links and the inner links alternating to provide a stable and space-saving structure.

[0011] According to a preferred embodiment, at least some of the chain links have first outer surfaces which together define a support plane for supporting a cutting tool. Such cutting tool can be a saw blade supported by the outer surfaces. Preferably, the cutting tool has a width sufficient for the cutting tool to be supported simultaneously by at least two first outer surfaces, for example by at least two first outer surfaces of two adjacent outer chain links.

[0012] According to a further preferred embodiment, at least some of the chain links have second outer surfaces which together define a second support plane for supporting a resection tool, the second outer surfaces being parallel to the first outer surface. In this way, a support plane for the resection tool can be provided regardless of whether the first surface or the second surface is arranged at the level of the resection plane (in other words, a support plane is provided both in the first orientation of the patella retainer and in the opposite orientation).

[0013] To improve the retention effect of the patella retention device, at least a portion of the chain links is provided with a protrusion or at least one protrusion arranged in the retention plane and configured to engage the patella. For example, the protrusion is arranged on the inner link of the chain. The at least one protrusion provides an anchoring or fixing element and may have a sharp corner such as a tooth or a hook.

[0014] According to a preferred embodiment, the first gripping element is configured to be operated by the thumb of the surgeon's hand and the second gripping element is configured to be operated, in particular, by the index finger of the same hand of the surgeon. The surgeon may use his right or left hand according to preference. In a preferred embodiment, the two gripping elements have the same shape and / or size.

[0015] To provide a comfortable handling, the gripping elements may be ring-shaped and / or trough-shaped. In a preferred embodiment, the two gripping elements have the same shape and / or size.

[0016] Further features and advantages are the subject of the following description and illustrative embodiments. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of one embodiment of a patella retainer. [Diagram 2] FIG. 13 is a perspective view showing the retention device initially engaging the patella. [Diagram 3] FIG. 13 is a perspective view showing the retention device fully engaged with the patella. [Figure 4] FIG. 4 is a perspective view of the arrangement and cutting tool according to FIG. 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] According to the drawings, the patella retainer 10 comprises two trough-shaped gripping elements 12 and 14. Each of the gripping elements may be manipulated by placing the top of the surgeon's thumb or the top of the index finger in the trough. In particular, the surgeon may use the thumb and index finger of the same hand.

[0019] The gripping elements 12 and 14 are connected to each other by a chain 16. The chain 16 comprises alternating outer chain links 18 and inner chain links 20. For example, the chain comprises ten outer chain links 18 and nine inner chain links 20. For example, each of the gripping elements 12 and 14 is connected to an outer chain link 18 in a preferably non-movable manner.

[0020] Adjacent links 18 and 20 are connected and movable relative to one another by chain pins 22, each of which provides an axis of rotation 24 about which adjacent chain links 18 and 20 can rotate or pivot within a retaining plane 26 of the patella retainer 10.

[0021] 2 illustrates the initial retention action of the patella retention device 10 within a retention plane 26 defined by the medial-lateral axis 28 and the proximal-distal axis 30 of the patella 32. The proximal-distal axis 30 is oriented parallel to the primary direction of the patellar tendon (not shown in the drawing).

[0022] The inner chain link 20 has a smaller width when viewed parallel to the axis of rotation 24 than the outer chain link 18 .

[0023] Preferably, each inner chain link 20 includes one tooth-shaped projection 34 configured to engage an engagement area along the periphery of the patella 32 .

[0024] Preferably, each outer chain link 18 includes two plates or tabs 36, 38 spaced apart from one another and overlapping the adjacent inner chain link 18 (see FIG. 2).

[0025] Each tab 36 of the outer chain link 18 has a first outer surface 40, and the plurality of outer surfaces 38 define a first bearing plane 42 (shown diagrammatically in FIG. 4).

[0026] The tabs 38 of the outer chain links 18 each have a second outer surface 44, the plurality of outer surfaces 44 defining a second bearing plane 46 (shown diagrammatically in FIG. 4).

[0027] The support planes 42 , 46 allow for the support and guidance of a cutting tool 48 , such as a saw blade, and with reference to FIG. 4, the cutting tool 48 is supported by the first support plane 42 .

[0028] To hold the patella 32, the surgeon may position the chain 16 and its chain links 18, 20 in a holding plane 26 around the circumference of the patella 32 (see FIG. 3). The two gripping elements 18, 20 may be positioned at any angular position within a clamping plane 34 (360 degrees of freedom).

[0029] The patella retainer 10 may be used in an inverted configuration with the gripping elements 18, 20 facing in opposite directions and the resection tool 48 supported by the second support surface 46.

Claims

1. A patella retention device (10) for retaining a patella (32) in a retention plane (26), comprising: The patellar support device (10) comprises: It comprises two gripping elements (12, 14) connected to each other via a chain (16) comprising chain links (18, 20), A patella retention device (10) characterized in that adjacent chain links (18, 20) are movable relative to one another about an axis of rotation (24) perpendicular to the retention plane (26).

2. 2. The patella retention device (10) of claim 1, wherein the retention plane (26) is parallel to or coincident with a plane defined by the medial-lateral axis (30) and the proximal-distal axis (28) of the patella (32).

3. The patella retaining device (10) according to claim 1 or 2, characterized in that the chain (16) has at least 8 rotation axes (24), preferably at least 12 rotation axes (24), in particular at least 16 rotation axes (24).

4. The patella retainer (10) according to any one of claims 1 to 3, characterized in that said chain (16) comprises at most 20 pivot axes (24).

5. The patella retainer (10) according to any one of claims 1 to 4, characterized in that the chain (16) comprises chain links (18) configured as outer links and chain links (20) configured as inner links, the outer links and the inner links being arranged alternately.

6. The patella retention device (10) of any one of claims 1 to 5, characterized in that at least a portion of the chain link (18) has a first outer surface (40) that together define a support plane (42) for supporting a resection tool (48).

7. The patella retention device (10) of claim 6, wherein at least a portion of the chain link (18) has a second outer surface (44) that together define a second support plane (46) for supporting a resection tool, the second outer surface (46) being parallel to the first outer surface (40).

8. The patella retention device (10) according to any one of claims 1 to 7, characterized in that at least a portion of the chain link (20) is arranged in the retention plane (26) and has one or at least one protrusion (34) configured to engage with the patella (32).

9. A patella retaining device (10) according to any one of claims 1 to 8, characterized in that the first gripping element (12) is configured to be operated by the thumb of the surgeon's hand and the second gripping element (14) is configured to be operated, in particular, by the index finger of the same hand of the surgeon.

10. The patella retaining device (10) according to any one of the preceding claims, characterized in that the gripping elements (12, 14) are ring-shaped and / or trough-shaped.

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