L-PLATE

Abstract: The present invention relates to an implantable buttress plate (1) for fixation of volar rim fragments (11) at the distal radius (10). The plate (1) is of L-shape with holes (5) in one or both of the legs of the L. The holes (5) are designed for receiving fastening means, e.g. bone screws (6). The plate (1) has a shape adapted to the intended use.

Description: L-PLATE The present invention relates to an implantable buttress plate according to the preamble of the independent claim. Frequently, fractures may involve the volar (palmar) portion of the distal radius including the volar rim. In some situations, such as the Barton's fracture, this type of fragmentation may be isolated, and con- tribute to volar (palmar) instability of the wrist as it displaces into the fracture site. In other fracture patterns, such as the comminuted Colles' fracture, volar fragmentation makes open reduction extremely difficult because of the lack of support of this rim. This may require multiple incisions if open reduction is attempted in order to reduce the dorsal fragmentation as well as re-establish a volar buttress for the wrist. This type of extensive soft tissue dissection, however, may further compromise the soft tissues. Typically, the buttress plate use for the above volar fragments is de- signed having a "T" type configuration and involves dissection through the midline along the palmar side of the distal forearm. The buttress plate is attached to the proximal fragment; distally, the plate pushes against the rim fragments holding them into position. The existing "T" buttress plates require a relatively long and exten¬ sive palmar exposure, retraction of the median nerve and radial vessels giving a relatively extensive bleeding. A further problem with this method is that in the presence of a comminuted Colles' fracture the surgeon is hesitant to have to make incisions from both the dorsal and the palmar side. One objective of the present invention is to provide a device circum¬ venting the above drawbacks. This will be attained by means of a buttress plate according to the characterizing part of claim 1. By using a buttress plate having an "L" type configuration according to the present invention, it is possible to apply the plate using a radial incision, which is less traumatic. The incision is made smaller than for the traditional palmar approach. Further objectives and advantages of the present invention will be ap- parent from the detailed description below. Expedient embodiments of the present invention are disclosed in the de¬ pendent claims. The present invention will now be described in greater detail herein- below, with the aid of embodiments shown in the drawings. In the accom¬ panying drawings: Fig. 1 is a top view of a buttress plate according to the invention; Figs. 2 and 3 are end and side views, respectively, of the plate of Fig. 1; Figs. 4 and 5 are top and side sectional views, respectively, of the plate of previous Figures, applied on the radius; and Fig. 6 is a top view of a further embodiment of a buttress plate according to the invention. One example of an embodiment according to the invention is shown in the Figures. The buttress plate 1 has a general L-shape in top view. The angle α between the two legs 2,3 of the "L" is approx. 90°. One leg 3 of the plate 1 is furnished with a number of openings 5 for receiving fastening means 6. At the transition 4 between the two legs 2,3 of the plate 1 an enlarged area is furnished at the outer part of the transi¬ tion 4. In other embodiments there is no such enlarged area. This tran¬ sition zone 4 is intended for support at the flare of the radial styloid. Both of the legs 2,3 are formed after the shape of the bone at which the plate 1 is fixed. The angle α between the legs 2,3 may vary from 60° to 115° in different embodiments of the invention. However, an angle α of approx. 75°-110° is the most common. In Figs. 4 and 5 an example of application on the radius 10 is shown. The L-plate 1 is used in this example as a buttress for a palmar rim fragment 11 at the distal radius. To place the buttress plate 1 a lim¬ ited incision is made along the radial side of the forearm. The base of the plate is slid up under the palmar soft tissue of the radius 10 to buttress the rim fragment 11. When the plate 1 is in the desire position it is fixed to the radius 10 by means of suitable fastening means passing through openings 5 in one of the legs 3 of the L-plate 1. In the drawings the fastening means are shown as screws 6. In other embodiments the screws 6 are replaced by pins, wires, blades, staples, brackets or indirect coaption with an¬ other device securely attached to the stable bone fragment. Further¬ more, a person skilled in the art appreciates that the number of aper- tures or holes for fixation of the plate 1 is not critical, as long as a stable fixation is achievable. The leg 2 of the buttress plate 1 intended to support the palmar rim fragment 11 is bent in a shape adapted to the form of the styloid of the radius. Thus, said leg 2 has a curved shape which follows the end of the radius. The other leg 3 of the buttress plate 1 is made con¬ toured for the radial side of the lower forearm. This allows a limited incision and makes it much easier for placement of the fastening means. The embodiment shown in Fig. 6 corresponds to the embodiment shown in Figs. 1 to 5 except that holes 12 are provided also in the leg 2 of the buttress plate 1 intended to support the palmar rim fragment 11. This allows the placement of fastening means, e.g. screws, in the part 2 of the plate 1 abutting the volar or palmar rim of the distal radius. In further embodiments pointed projections (not shown) are furnished at the ends of the plate. These pointed projections aid in purchasing the fragments that are buttressed, and prevent the fragments from shifting. The above detailed description has referred to but a limited number of embodiments of the present invention, but it will be readily perceived by a person skilled in the art that the present invention encompasses a large number of embodiments without departing from the spirit and scope of the appended claims.

Claims: CLAIMS 1. An implantable buttress plate (1) for fixation of a palmar or volar rim fragment (11) at the distal radius (10), c h a r a c t e r - i z e d in that the plate (1) is of L-shape as viewed from above. 2. The plate of Claim 1, c h a r a c t e r i z e d in that only one leg (3) of the "L" is furnished with one or more holes (5) for re¬ ceiving fastening means (6) for securing the plate (1) to a stable bone (10). 3. The plate of Claim 1, c h a r a c t e r i z e d in that both legs (2,3) of the "L" are furnished with one or more holes (5,12) for receiving fastening means (6) for securing the plate (1) to a stable bone and/or bone fragments. 4. The plate of any of the preceding Claims, c h a r a c t e r ¬ i z e d in that the area of the plate (1) is enlarged, as viewed from above, at the outer part of the transition (4) between the two legs (2,3) of the "L". 5. The plate of any of the preceding Claims, c h a r a c t e r ¬ i z e d in that one leg (2) of the "L" is bent in a shape adapted to the form of the styloid of the radius (10). 6. The plate of any of the preceding Claims, c h a r a c t e r ¬ i z e d in that it is designed for use through a single, limited incision along the radial side of the lower forearm. 7. The plate of any of Claims 2-6, c h a r a c t e r i z e d in that the fastening means are screws (6), pins, wires, blades, staples, brackets or indirect coaption with another device securely attached to the stable bone (10). 8. The plate of any of the preceding Claims, c h a r a c t e r ¬ i z e d in that the angle (α) between the two legs (2,3) of the "L" is from 60° to 115°. 9. The plate of any of Claims 1 to 7, c h a r a c t e r i z e d in that the angle (α) between the two legs (2,3) of the "L" is from 75° to 100°. 10. The plate of any of the preceding Claims, c h a r a c t e r ¬ i z e d in that the ends of the plate (1) are furnished with pointed projections.

Inventors: MEDOFF ROBERT J, MEDOFF, ROBERT, J.
Applicants: COLLUX AB, MEDOFF ROBERT J, MEDOFF, ROBERT, J.
Application year: 1996
Main classification: A61B17
IPC codes: A61B17