ES2374808B1 - DEVICE FOR PARTIAL ARTRODESIS DEL CARPO. - Google Patents

Abstract

Partial carpal arthrodesis device. # A device and a procedure for the immobilization of radio-scapho-semilunar joints are described using arthrodesis techniques that are given by a plate with three sections, where each of these sections is placed on each of one of the bones to be joined by screws.

Description

doll is the only technique that will be achieved

Carpal partial arthrodesis device.

Object of the invention

The present invention relates to the field of medical implantology, more specifically in those implants intended for immobilization of joints.

The object of the invention consists of a device that allows immobilization of the bone structure by anchoring said device to the bones that make up said structure. Background of the invention

The arthrodesis operation consists of a surgical intervention in which two bone pieces are fused, eliminating a joint. This intervention is very common in the spine by fixing two or more vertebrae to each other, generating the initial fixation by means of more or less complex metal implants, which prey on the pedicles, plates or apophyses of the vertebrae, while the definitive fusion takes place, biological process that results from the debridement of the articular segments to be sacrificed and contribution of graft or bone substitute.

Arthrodesis has been and is a very important therapeutic weapon in the treatment of advanced degenerative joint disease, since arthroplasty is not applicable to all joints or at least, it does not offer the best clinical-functional results for certain lesions and topographies. These types of techniques were performed on the wrist as an alternative to joint resection or amputation in tuberculous conditions. Other early indications of arthrodesis were the correction of polio deformities, spastic deformities, as Steindler described in 1918, and sequelae of Volkmann's ischemic contracture.

In 1965, Clayton and others, described the use of long Steinman nails, for the fusion of the rheumatic wrist. In 1971, Mannerfelt and Malmstem modified the procedure using Rush nails, inserted through the 3rd metacarpal to the radius dialysis, in combination with a Wiberg staple, to ensure rotational stability, a procedure that became very popular and resulted in to multiple variants (Stanley 1986) applicable to closed wrist arthrodesis and open sky. Doll fusion with plates and screws was introduced by the AO group in German literature in 1969 and translated into English in 1970. Larson in 1974 described a series of 23 patients with wrist fusion with compression plate using the AO method.

At present, total wrist arthrodesis is a well-established surgical procedure that provides a reproducible reduction of pain in patients with multiple inflammatory, degenerative or post-traumatic conditions, although sacrificing all mobility.

Palmer et al in 1985, described the degree of mobility necessary to perform most of the activities of daily living, the so-called functional mobility, which is 5º of flexion, 30º of extension, 10º of radial inclination and 15º of ulnar inclination.

The wrist has 2 main articular lines: the radiocarpal joint (between the bones of the forearm and the first row of carpal bones) and the midcarpal (joint line between the two rows of the carpus). When the injury or affects the joints the disappearance of pain.

However, when the degenerative condition affects only part of the wrist. The "partial" or focal arthrodesis (only of the affected area), has the advantage, at least theoretical of alleviating pain, preserving part of the mobility (that provided by the unaffected joint segments) and therefore improving the overall function of The wrist unit.

One type of partial wrist arthrodesis is radio-scapho-semilunar arthrodesis, which would be indicated in cases where there is joint degeneration limited to the radiocarpal joint, as occurs in the sequelae of fractures of the distal extremity of the radius, early stages of posttraumatic carpal osteoarthritis (SLAC doll) and in rheumatoid arthritis patients with wrist involvement.

This type of intervention does not spread much, since among other complications there is a considerable rate of pseudoarthrosis (non-union of arthrodesis). This contributes to the absence of a primary fixation device appropriate to the anatomy and pathology of the region. It is customary to use non-speci fi c materials from which other problems derive, because they provide only one fixation point for carpal bone. Description of the invention

The device object of the invention offers a series of advantages over the known devices, since it allows performing partial wrist arthrodesis operations like radio-scapho-semilunar arthrodesis.

For the realization of the immobilization of radio, scaphoid and semilunar, the device object of the invention has a symmetric or asymmetric "Y" configuration and would be made of titanium, whose biological compatibility is demonstrated and allows magnetic resonance scanning after the intervention surgical

In a configuration of the device one of the sections, the second section, coincides in its longitudinal axis with the first section and therefore appears as a continuation of said first section, while a third section starts from the junction point between said second section and the first section, although in this case the longitudinal axis of said third section defines a non-zero angle with respect to that of the first two sections, which is coincident between both first and second sections. This configuration has the appearance of a lowercase "y".

In another configuration of the device, the second section is not a continuation of the first section and forms an angle with respect to the first section and the third section, which as in the previous configuration also defines a non-zero angle with the first section. This configuration has the appearance of a capital “Y”.

The joints between the device and the bones of the joint are given by screws of 2.4 mm, in number of two, for each of the carpal bones in two different angles.

The anchor offered by the second oblique screw supports two-way axial and tangential stresses, providing greater mechanical resistance to the device, thus strengthening the immobilization of the joint.

The device has small guides (screw hole path) for drilling

3 EN 2374808A1 4

direct the screws to predetermined points of the bones to be fixed and that have been checked with radiographic templates of normal and pathological carps.

First, the perpendicular screws to the scaphoid and semilunar would be placed and then the radius screws, which when introduced by oval holes (designed for this purpose in the main vertical branch of the plate) allow self-compression of the bones to be arthrodesed (improvement bone union rate), to finally block this position with the oblique direction screws in scaphoid and semilunar.

To avoid the possible secondary mobilization of the osteoporotic bone screws (fragile, not very dense), these are also threaded to the plate, which has been shown with other devices that significantly increases the stability of the system.

The device object of the invention also has a series of accessory holes to temporarily fix with needles and to be able to assess the proper placement thereof by radioscopy.

Finally, to facilitate the use of the implant, it has in its sections some holes designed to house a centering device that allows the device to be placed and aligned with the bones to be joined and facilitates intraoperative manipulation. Description of the drawings

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description. where, for illustrative and non-limiting purposes, the following has been represented:

Figure 1.- It shows an overhead view of the device object of the invention with the fork of the smaller sections con fi gured in the form of "Y".

Figure 2.- It shows an overhead view of the device object of the invention with one of the smaller sections coinciding with the greater section; showing a “y” setting.

Figure 3a.-Shows the device of the invention con fi gured in “Y” on an x-ray of the wrist.

Figure 3b.-Shows the device of the invention con fi gured in "y" on an x-ray of the wrist.

Figure 4.- Shows the device of the invention con fi gured in "y" with the center mounted. Preferred Embodiment of the Invention

In view of the figures, a preferred embodiment of the device (1) object of this invention is described below.

To perform a partial wrist arthrodesis, the device (1) is positioned on bones to be immobilized: radius, scaphoid and semilunar; For this purpose, a centering device (8) is used. The device (1) has a series of accessory holes (5) in the main branch and in each of the sections (2, 3, 4) of the device (1) so that, by manipulating said centering (8) , the device (1) can be positioned and fixed in holes designed to house said center (8), temporarily with Kirschner needles to assess correct alignment by radioscopy.

To make the immobilization it is necessary to anchor the device (1) to each of the bones by screws, the screws are 2.4 mm for the carpus and 3.5 mm for the radius, which are fixed perpendicularly to the bone passing through perpendicular through holes (7) while other screws, which form the anchoring pair, are obliquely fixed to the bone through oblique through holes (6) and always after fixing to the radius; Each anchor pair is defined in each of the sections (2, 3, 4).

5 EN 2374808A1 6

Claims (10)

1. Partial arthrodesis device of the carpus characterized in that it comprises a body of rounded shapes that is constituted by a first section (2) which has a fork from which a second section (3) and a third section (4) depart, which forms an angle with said first section (2), where said body has:

-

at least one oblique through hole (6) that is defined in at least one of the sections (2, 3, 4), and

-

at least one perpendicular through hole (7) that is defined in at least one of the sections (2, 3, 4).

2.

Device (1) according to claim 1 characterized in that the second section (3) is collinear with the first section (2) and the third section (4) is angled.

3.

Device (1) according to claim 1 characterized in that the second section (3) is arranged at an angle with respect to the first section (2).

Four.

Device (1) according to claim 3 characterized in that the second section (3) and the third section

(4) are arranged so that the body is symmetrical.

5.

Device (1) according to any one of the preceding claims characterized in that it additionally comprises accessory holes (5) that are located in at least one of the sections (2, 3, 4) adapted to allow the temporary fixation of the device by means of needles.

6.

Device (1) according to any one of the preceding claims characterized in that it additionally comprises a centering device (8) intended to manipulate and position the device (1).

7.

Device (1) according to any one of the preceding claims characterized in that it additionally comprises in its sections (2, 3, 4) some holes intended to house the centering device (8).

8.

Device (1) according to claim 7 characterized in that the screws are "threaded" or locked to the plate to prevent mobilization in osteoporotic bone.

9.

Device (1) according to claim any one of the preceding claims characterized in that at least one of the holes (6, 7) of the first section (2) intended for the radius are oval to allow self-compression of the system.

SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201030216 SPAIN Date of submission of the application: 02/16/2010 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: A61B17 / 80 (2006.01) RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

X

US 2006173459 A1 (KAY DAVID B. et al.) 03.08.2006, 1-9

paragraphs [5], [7], [9-10], [46-48], [50], [52], [56]; Figures 1-2,28-31.

X

US 2009281543 A1 (SKELETAL DYNAMICS LLC.) 12.11.2009, 1.3-7.9

paragraphs [3], [13], [17], [21], [62], [64], [69], [70-72]; Figures 13A-13B, 28-44.

TO

US 6221073 B1 (KINETICOS MEDICAL INC.) 24.04.2001, 1.3-4

column 2, lines 5-28; column 3, line 1 - column 4, line 24; Figures 1-3.

TO

US 5853413 A (BRISTOL-MYERS SQUIBB CO.) 29.12.1998, 1.3-4

column 2, line 60 - column 3, line 45; figures 1-2.

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 08.02.2012

Examiner J. Square Prados Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE Minimum documentation sought (classification system followed by classification symbols) A61b Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC, WPI, PAJ, ECLA.  WRITTEN OPINION Date of Completion of Written Opinion: 08.02.2012 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 2, 4-7 1, 3, 8-9 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-9 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base. This opinion has been made on the basis of the patent application as published.  WRITTEN OPINION 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 2006173459 A1 03.08.2006

D02

US 2009281543 A1 12.11.2009

D03

US 6221073 B1 04.04.2001

D04

US 5853413 A 29.12.1998

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement The invention as defined in the first claim is considered to be novel because it is included in the state of the art, since document D01, cited in the Report and valued as the closest state of the art, can be considered which anticipates the object of protection defined in a somewhat generic manner in that claim. Indeed, in document D01 (see parts cited in the EIT, mainly Figures 1-2, 28-31) it is described (references in brackets apply to that document) a:

-

Partial arthrodesis device (see paragraph 7, partial fusion) of the carpus (see paragraph 7, small bones ie carpals, radius, ..) comprising a body of rounded shapes (710, figure 28) that is constituted by a first section ( trunk portion, 712 ') which has a fork from which a second section (720 on one side, figure 28) and a third section (720 on the other side, figure 28), which forms an angle with said first section ( 712 '), where said body has:

�

at least one oblique through hole (see paragraph 50, screw hole 24) that is defined in at least one of the sections (720), and

�

at least one perpendicular through hole (see paragraph 47, through hole 14, 714) that is defined in at least one of the sections (712 ’).

Therefore, the device of document D01 contains all the features of the first claim, so that it is not new. It should be noted that document D02 cited in the EIT would also serve to question at least the inventive activity of the main claim, since it cites the possible intended use (see paragraphs 3, 17, 21) and includes some embodiments that present the claimed form (see figures 13A-13B) and the rest of the characteristics related to the through holes (oblique, see paragraphs 64 and 66). When assessing the contribution of the object of the application with respect to the state of the art, it is necessary to consider the one described in the description as a problem of the current state of the art (see page 3, lines 16-19, “the devices of fixation are not adequate because they provide only one fixation point for carpal bone, which results in high rates of pseudoarthrosis ”) and the solution provided to it (see page 3, line 27, fixation to more than one carpal bone). Well, this type of solution consisting of fixation to the radius and at least two carpal bones (for example scaphoid and semilunar) is known and has been previously proposed as can be seen in D03. Dependent claims 2 to 9 delimit a series of additional optional and theoretically non-essential features on which it can be considered that, in combination with those of the main claim on which they depend, they do not contain additional features of novelty or inventive activity with respect to Document D01 for the following reasons:  WRITTEN OPINION The second claim lacks inventive activity in view of document D01 since it indicates (see paragraph 48) that the second section forms an angle that can be 5 ° with respect to the first section, and the third section is angled ( between 10º and 35º). An angle of 5º for the second section can be considered almost collinear (0º theoretical), and no inventive activity can be seen in that possible difference, especially when it seems a mere choice between different design possibilities for the device, and it also does not indicate or imply in the entire application the possible technical effect that is obtained with that particular design (difference of 5º) nor the technical problem that is intended to be solved with it. The applicant does not explain why that particular design proposed in this claim is not only a choice between the designs proposed in the state of the art or other possible ones, which should be considered out of reach for a person skilled in the art due to a special technical effect. not derivable from the state of the art. Said design could only be considered to have inventive activity if it had an unexpected effect or property in relation to a design such as that indicated in D01. However, these effects or properties have not been presented in the application, and it is referred to as a possible “configuration” (page 4), so it seems rather an option among the various possible with a view to adapting the application. device to its intended use. Therefore, no inventive activity is appreciated in the object of the second claim. The third claim, dependent on the main one, is novel in view of document D01, since in the same "the second section is arranged at an angle to the first section" (see figures 1, 28, paragraph 48) . The fourth claim is considered to lack inventive activity since although the device presented in D01 has a bilateral asymmetry, in document D02 (Figure 13A) it is advanced that "the second section and the third section are arranged so that the body is symmetric ”(Y shape). Again it seems obvious to a person skilled in the art from the device presented in D01 to propose a variant with these characteristics (symmetry) from the state of the art known by D02, especially when again the considerations given to justify the application are applicable. lack of inventive activity of the second claim. The fifth, sixth and seventh claims add a series of minor accessory characteristics which, being well known in the state of the art, are considered obvious to any person skilled in the art:

-

the characteristic of the fifth claim, that the device "additionally comprises accessory holes that are located in at least one of the sections adapted to allow temporary fixation of the device by means of needles" is anticipated in D02 (see paragraphs 13 and end of 73).

-

The characteristics of the sixth and seventh claims are anticipated in D02 as this document includes a "centering device for manipulating and positioning the device" and "holes intended to house the centering device" (see paragraphs 70-72, figures 33 -44).

The eighth claim, whose dependence on the seventh seems inadequate and is considered to depend on the principal, is not new in view of document D01, since it is provided that "the screws are threaded or locked to the plate" ( see end of paragraph 52 “bore could be threaded”). Finally, the ninth claim, dependent on the main one, also lacks novelty in view of document D01, since it is provided that "at least one of the holes in the first section for the radius are oval to allow self-compression of the system ”(see paragraph 46, reference 14, slotted or elongated compression holes).