The invention relates to a holding device comprising a flexible member and a support member configured to lie against a bone.
Such holding devices are for instance used for ligament reconstruction. A ligament, such as the anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL), which has ruptured in a non-repairable way, may be replaced arthroscopically by a tissue graft, which may be harvested form another portion of the body or which may be artificial. The holding device is used to attach the tissue graft to the bone, e.g. the femur.
One holding device available on the market is sold under the name RetroButton®. This product comes in a set of titanium buttons with various sizes and continuous loops with different length. During operation, the surgeon chooses out of the set that button which has the loop with the appropriate size so that the tissue graft can be attached with the desired strength. However, the provision of various sizes makes manufacturing as well as storage and handling at the consumer's side complicated.
The patent application EP 2 476 378 A1 describes a holding device in form of an anchor comprising an anchor body, a continuous closed suture loop and an insert. For assembling the anchor a portion of the suture loop is passed through an opening in the anchor body and secured by the insert. The size of the loop is fixed. This has the disadvantage mentioned above that several anchors with different sizes have to be provided, out of which the surgeon chooses an anchor which is suitable to attach a specific tissue graft with the desired strength.
The patent application WO 2009/036286 A1 relates to a device of a kind that is different from the holding devices mentioned above. There is provided an anchor block having a knob for engagement of one end of a tension member. The other end of the tension member is configured for an engagement with a tissue. No flexible member is provided over which e.g. a tissue graft can be looped for attachment.
The patent application US 2013/0116787 A1 discloses a holding device comprising a support member and a ratchet mechanism, which is formed of solid members and which serves for adjusting the length. The design of this holding device is relatively complicated. Particular measures have to be taken in order to avoid a loosening of the ratchet mechanism, once it is implanted.
It is an aim of the present invention to provide for an improved holding device that it is adjustable in size.
This aim is achieved by the holding device as defined in claims 1. The further claims specify preferred embodiments of the device.
There is provided a support member having two attachment locations for attachment of the ends of a flexible loop member. The latter has a plurality of eyelets, through which a portion of an attachment element of the support member can be passed. This has the advantage that the effective length of the loop member, i.e. the length, which the loop member has between the two attachment locations, is adjustable by choosing a specific eyelet for the attachment. The end part of the loop member which is too long may be cut away. The eyelets allow also a simplified handling of the holding device by passing e.g. an auxiliary suture therethrough for shuttling the holding device through a bore.
Providing the loop member as a braid results in a structure having a high strength, in particular at the bifurcating and converging locations of the eyelets.
Preferably, the holding device has one or more of the following features:
Additional features and their advantages will be become apparent from the following description of exemplary embodiments and from the drawings, where
The length Le of the eyelets 5a, 5b may be the same or vary. The length Lc of the central portions 3 may be the same or vary. For instance the length Lc of the central portions 3, which are near the first end 1a, may be different to the length Lc of the central portions 3, which are near to the second end 1b. This increases the possibilities of choosing a particular length between the first end 1a and an eyelet 5b near the second end 1b. In one embodiment, the loop member 1 has an intermediate portion which is arranged between the ends 1a, 1b and which is free of eyelets 5a, 5b. The length of this intermediate portion may be greater than the length of the end 1a with the eyelets 5a and/or the length of the end 1b with the eyelets 5b.
The width Wc of the central portions 3 may be the same or vary and the width We of a branch portion 4a, 4b may be the same or vary. In one embodiment, the width Wc of each central portion 3 is substantially constant and/or approximately twice the width We. In another embodiment, the loop member 1 has an intermediate portion which is arranged between the ends 1a and 1b and which is greater in thickness Wc than the ends 1a and 1b. Thereby, a particular large supporting surface to support a graft tissue can be provided.
Preferably, the plate 11 has a form which is free of sharp areas by rounding off e.g. the corners and/or edges. The plate 11 comprises a blind hole 13 which extends from a lateral side of the plate 11 through the first window 12a and which is adapted to receive a fixation pin 14. The diameter of the blind hole 13 is configured such that the fixation pin 14 may be press-fitted therein.
An attachment mean 15 to attach the second end 1b of the loop member 1 is arranged adjacent to the second window 12b. Here, the attachment mean is a tongue 15 which is preferably made integral with the plate 11 and which may be configured such that it is rigid or bendable. The plate 11 may comprise a recess 16 opposite to the tongue 15 to receive part of the loop member 1.
The holding device may be preassembled such that the first end 1a of the loop member 1 is already fed through the window 12a and fixed by passing the fixation pin 14 through an eyelet of the loop member 1, whereas the second end 1b of the loop member 1 is loose. The holding device may be sterilized and packed.
The configuration of the loop member 1 is adapted to the desired usage of the holding device. For instance, the loop member 1 may be configured such that eyelets are provided near the ends 1a, 1b, whereas the intermediate portion, which is indicated in
The holding device is for instance usable to reconstruct an anterior cruciate ligament as shown in
In an alternative usage, it is conceivable to provide a loop member 1 long enough so that the intermediate portion of the loop member 1 only is moved through the tunnel T1, T2 to attach the graft tissue and pulled back again, whereas the support member 1 and the two ends 1a, 1b remain during operation outside the tunnel T2.
Various possibilities are conceivable to attach the second end 1b of the loop member 1 to the support member.
Another possible embodiment of attaching the second end 1b of the loop member 1 to the support member is described below with regard to
The attachment element 41 includes an intermediate portion 43 and two arms 44a, 44b which are arranged in line with each other and which are attached to the lateral sides of the intermediate portion 43. The grooves 34a, 34b and the arms 44a, 44b are designed to enable a snap engagement. To this end, the cross-section of a groove 34a, 34b may have an undercut so that an arm 44a, 44b when pressed into the corresponding groove 34a, 34b is retained therein.
When using the holding device according to the second embodiment for replacement of a ligament, the surgeon puts the tissue graft around the loop member 1 and guides each arm 44a, 44b of the attachment element 41 through an eyelet of the loop member 1 so that the portion of the loop member 1 between the arms 44a, 44b has the desired length. Subsequently, the attachment element 41 together with the ends 1a, 1b of the loop member 1 is attached to the plate 31 by pressing the arms 44a, 44b into the grooves 34a, 34b. A suture which extends through a tunnel T formed in the bone B is passed through one of holes 32a, 32b of the plate 31. By pulling on the suture the elements 1, 31, 41 can be moved through the tunnel T′ until the support member 31, 41 comes out of the tunnel T′ and can be arranged such that the bottom side 31a abuts the bone surface. In an alternative application, it also possible to pull only the ends 1a, 1b of the loop member 1 through the tunnel T′ and subsequently attach them to the plate 31 by means of the attachment element 43.
The attachment element 61 includes an intermediate portion 63 and two arms 64a, 64b which are arranged in line with each other and which are attached to the intermediate portion 63. The grooves 54a, 54b and the arms 64a, 64b are designed to enable a snap engagement. To this end, the cross-section of a groove 54a, 54b may have an undercut so that an arm 64a, 64b when pressed into the corresponding groove 54a, 54b is retained therein.
When using the holding device according to the third embodiment for replacement of a ligament, the surgeon drills a boring T′ in the bone B, e.g. the femur. The inlet of the boring T′ may be formed such that it is adapted to the outer surface 56a of the tubular element 51. For instance, the inlet of the boring T′ may be formed cylindrically or conically to receive a cylindrical or conical insert portion 56. The loop member 1 and the graft tissue attached thereto are pulled through the boring T′ by means of a shuttle suture which has been passed through two eyelets in the end 1a and 1b of the loop member 1. Subsequently, each arm 64a, 64b of the attachment element 63 is passed through an eyelet at the end 1a and 1b, respectively, so that the loop member 1 has the desired length therebetween. The attachment element 63 is then attached to the tubular element 51 which is received in the boring T′.
The handling of the holding device is similar to the ones described above. The loop member 1 is attachable to the support member 71, 81 by passing the arm 83 first through an eyelet of each arm 1a, 1b and then into the blind hole 72.
The second plate element 81 may be formed in one or more pieces. A particular simplified variant is to provide a support member including two elements in the form of the first plate element 71 and a pin 83′, which can be pushed into the blind holes 72 of first plate element 71. This variant is shown in
The support member comprises a plate 91 having a flat bottom side 91a to be contacted to a bone and two through-going windows 92a, 92b which are adapted to pass therethrough the ends 1a, 1b of the loop member 1. Preferably, the plate 91 has a form which is free of sharp areas by rounding off and/or chamfering e.g. the corners and/or edges. The plate 91 comprises a blind hole 93 which extends from a lateral side of the plate 91 through the first window 92a and which is adapted to receive a fixation pin 14. The diameter of the blind hole 93 is configured such that the fixation pin 14 may be press-fitted therein.
An attachment mean 95 to attach the second end 1b of the loop member 1 is arranged in the second window 92b. Here, the attachment mean is a hook 95 which is preferably made integral with the plate 91. The hook 95 extends into the window 92b such that there is a free space 96 between the hook 95 and the walls of the plate 91 which define the window 92b. This space 96 allows the user to pass the end 1b of the loop member 1 through the window 92b, to move it relative to the hook 95 and to put it thereover such that the hook 95 extends through a specific eyelet and the portion of the loop member 1 between the fixation pin 14 and the hook 95 has the desired length.
As is in particular apparent from
The holding device may be preassembled such that the first end 1a of the loop member 1 is already fed through the window 92a and fixed by passing the fixation pin 14 through an eyelet 5a of the loop member 1, whereas the second end 1b of the loop member 1 is loose. The holding device may be sterilized and packed.
In the embodiment shown in
Instead of the end portion 1b″ or in addition thereof the second end 1b of the loop member 1 may be provided with a shuttle suture 19′ similar as shown in
A support member according to an embodiment described above is made from a biocompatible material, e.g. metal such as titan or plastic such as PEEK (polyether ether ketone). The holding device according to the second, third and fourth embodiment may be packed such that the pieces of the support member and the loop member form loose parts, which can put together during surgery.
The loop member 1 is made as a fabric in form of a braid. A braid is a structure formed by interlacing strands of flexible material. Each strand passes alternately over and under one or more of the others. The braid may be two dimensional or three dimensional. In the latter case, a strand runs through the braid in all three directions. All or at least some of the strands of the loop member 1 extend continuously from the first end 1a to the second end 1b. In an embodiment, in which a loop member 1 has an intermediate portion which is thicker than the ends 1a, 1b (see
The braided loop member 1 has a high strength. The strands are interlaced such that they do not get separated from each other when for instance a force acts on the location of the bifurcation or convergence of an eyelet 5a, 5b. The location of bifurcation/convergence can be reinforced e.g. if necessary with an additional thermal in line process after the braiding.
The loop member 1 may be fabricated by means of a braiding machine comprising bobbins, which carry the strands. In the braiding operation, the bobbins are advanced along specific paths of travel, see e.g. EP 2 492 385 A2. The number of bobbins may be 12 up to several dozens, e.g. 120.
The loop member 1 is made from a biocompatible material. A strand to be used for braiding includes fibers of the same or different type. Examples of suitable materials for the fibers are:
It also possible to combine different types of fibers, known as fiber blends, to produce the loop member 1, e.g. polyester with polyamide, polyester with hemp, flax with silk, etc.
A fiber may be formed as a single yarn or as multiple yarns, which are twisted together or are combined without twist.
Other braided structures for the loop member 1 are conceivable, for instance flat braids having bifurcating and converging portions to define eyelets.
Machines arranged for flat braiding cause the yarn carriers to move on a line back and forth. This results in a flat structure without an interior. Machines arranged for tubular braiding cause the yarn carriers to move in a circle. This results in a tubular structure having an interior, which may or may not include a core.
Individual components of the loop member 1, i.e. fiber, yarn, strand, core, etc., or the loop member 1 as a whole may be provided with an additional layer obtained e.g. by impregnating a substance or by plasma deposition.
The holding device has various medical applications. It can be used e.g. in the reconstruction of knee ligaments, in particular the anterior cruciate ligament and the posterior cruciate ligament. In these applications, the holding devices serve to attach a tissue graft replacing the ligament so that it has the desired strength. Another application is in the treatment of injuries of the acromioclavicular joint (AC joint), which is the joint at the top of the shoulder. In one application, the holding device is used to stabilize the clavicle to the coracoid process. To this end, the surgeon may drill a tunnel into the clavicle, loop the loop member around the coracoid process and attach it to the support member.
The advantages of the embodiments described so far can be summarized as follows:
Number | Date | Country | Kind |
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15178204.2 | Jul 2015 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2016/063798 | 6/15/2016 | WO | 00 |