KIT FOR THE SURGICAL TREATMENT IN ARTHROSCOPY OF ANTERIOR CHRONIC SHOULDER INSTABILITY WITH ANTERIOR CAPSULAR LIGAMENTOUS DEFICIT
DESCRIPTION
The present invention lies in the field of surgery, in particular of arthroscopic surgery.
More precisely, the present invention refers to a tool kit for the surgical treatment in arthroscopy of anterior chronic shoulder instability, specifically contrived for carrying out a method of arthroscopic treatment of said pathology.
It is known in the literature that, in anterior shoulder instability, the subscapularis tendon plays a fundamental role both from the structural and biomechanical standpoint.
It has been demonstrated by Symeonides, in 1974, that repeated episodes of anterior dislocation cause an elongation of the subscapularis tendon, which can reach a length 1 .5 cm greater than the contralateral one.
A repair of the sole capsulolabral complex oft-times is not sufficient to prevent a recurrence, as it does not correct such elongation.
In these cases, in 1986, Lenny Johnson had proposed an intervention in arthroscopy, using the intra-articular portion of the subscapularis tendon with fixation to the glenoid by a rudimentary metal clamp.
However, in spite of good results reported by the Author, the technique had given rise to criticisms linked to clamp use, so much as to be soon abandoned.
The arthroscopic treatment of anterior shoulder instability would entail numerous advantages in comparison with open techniques, due both to reduced complications and better cosmetic result. However, despite the various techniques used, failure rate up to now has been very high. This ensues from the presence of serious capsuloligamentous laxities, poor-quality capsular tissue, or bone deficits.
For these reasons, to date arthroscopic technique for the treatment of anterior shoulder instability, especially in chronic form, has in fact been abandoned and replaced by open surgery techniques.
However, it is well evident and known, as already indicated, that open surgery entails a series of drawbacks and inconveniences for the patient, particularly burdensome and heavy in terms of intervention length, complications, post-operative course, etc.
Therefore, object of the present invention is to solve the problems still left open by the known art, and this is attained by a tool kit for the surgical treatment in arthroscopy of anterior shoulder instability as defined in claim 1 .
The present invention, by overcoming the problems of the known art, entails numerous evident advantages.
In particular, the present invention enables to minimize arthroscopic technique failures linked to anterior soft tissue alterations, which are nearly always present after the third or fourth dislocation.
From the biomechanical standpoint, in the motion of arm abduction the subscapularis tendon slides upward, exposing the humeral head into contact with the sole lower capsulolabral complex, which oft-times when the repaired tissue is of poor quality, fails to stabilize the joint. Then, tenodesis of the subscapularis to the glenoid enables not only to restore retensioning of the tendon, but also reduces its upward sliding in a raising of the arm, enabling it to act as anterior stabilizer of the humeral head and assist the antero-inferior capsule in preventing recurrences.
Other advantages, along with the features and the modes of employ of the present invention, will be made evident in the following detailed description of preferred embodiments thereof, given by way of example and not for limitative purposes. Reference will be made to the figures of the annexed drawings, wherein:
- Figure 1 A shows a healthy shoulder, in particular the articular capsule and the subscapularis tendon;
- Figure 1 B shows a shoulder after an anterior dislocation;
- Figure 1 C shows the shoulder in which repeated dislocations have produced a relaxation of the subscapularis tendon;
Figure 1 D shows the shoulder of Figure 1 C for which the sole repair of the anterior capsulolabral complex has been performed;
- Figures 2 to 7 show some components of the kit;
- Figures 8 to 17 show, in sequence, the main operative steps of the surgical intervention according to the present invention;
- Figures 18 and 19 show a shoulder joint operated according to the present invention;
- Figures 20 and 21 show the results of the operation in comparison with the preoperative situation.
The present invention will hereinafter be described in detail by making reference to the above-indicated figures.
In particular, Figures 1 A to 1 D illustrate the evolution of the lesion, from a "normal" shoulder (Fig. 1 A) that has undergone repeated dislocations (Fig. 1 B), until anterior capsulolabral complex breakage (Fig. 1 C).
In Figure 1 D it is shown a shoulder, following a repair of the anterior capsulolabral complex, for which however is evident the elongation undergone by the subscapularis tendon that, unavoidably, does not perform its containing function anymore.
According to the present invention, a method for the surgical treatment in arthroscopy of anterior shoulder instability, comprises the following steps: - performing a lower capsuloplasty, and
- performing a tenodesis of the subscapularis tendon to the scapular glenoid by means of a self-locking abutment tenodesis anchor and a retainer of tape- shaped type.
For a correct and advantageously effective carrying out of the method according to the present invention, a tool kit has been expressly contrived.
In particular, for performing the tenodesis of the subscapularis to the glenoid, it is envisaged the use of a kit for the surgical treatment in arthroscopy of anterior shoulder instability, comprising at least one self-locking abutment tenodesis anchor and at least one retainer of tape-shaped type.
Figures 2 to 7 show some of the components of the kit according to the present invention.
In particular, the tenodesis anchor (Figure 2) is preferably made of Peek® material. By way of example, an anchor of Push Lock® type, like the one produced by the Arthrex® Company, could be used for the kit.
The tenodesis anchor could be selected of the most appropriate dimensions depending on the needs. Preferably, a 3.5 mm anchor could be used.
As a rule, for this type of anchors the use of a suture wire is advised. However, a use of the anchor with a common suture wire in an intervention as the one described would be absolutely contraindicated, since a standard suture wire would not enable to tension the tendon without damaging it, with the outcome however of nullifying the results of the intervention itself.
Therefore, according to the present invention, the retainer is first of all tape-shaped and is formed by a braid of osteosuture wires (Figures 4, 5).
Preferably, the braid has a thickness comprised between 2 and 3 mm and a length comprised between 70 and 105 cm. In order that the tenodesis anchor be particularly suitable for use with a retainer as presently described, it would be preferable that it were made with a slot of dimensions suitable to allow an immediate insertion of the retainer and an easy sliding thereof within the slot itself. Advantageously, therefore, the slot might have dimensions comprised between 1 ,2 and 1 .5 mm of width and 2.1 and 2.6 mm of height.
By way of example, a useful retainer might be Fibertape® of the Arthrex® Company. The use of this tape is indicated for the repair of rotator cuff tendons, an intervention envisaging a technique completely different from the one described hereto.
Fibertape® is formed by braided osteosuture wires having a core of polyethylene and a jacket of polyester. It has a central region thicker than the free ends, region which, utilized in the intervention according to the present invention, allows to tension tendon tissue in a better way than a common suture wire, without damaging it.
Advantageously, the kit according to the present invention may also comprise one or more anchors to be used for lower capsuloplasty, and suture wire suitable for capsular tissue, for instance Fiberwire® wire of the Arthrex® Company.
Capsuloplasty anchors may, advantageously, be of the same type of the tenodesis anchor, i.e. anchors of PushLock® type.
Further, the kit according to the present invention may moreover comprise at least one bone drill (Figure 6C), for making a housing for the tenodesis anchor, of a gauge suitable to the anchor size, a duckbill scope inside which to slide the burr in order to avoid burr skidding, and/or a shutter for highlighting exactly the direction of the bore before implanting the anchor.
Moreover, the kit may also comprise a tool for positioning and bone anchoring of the anchors (Figure 3). Hereinafter, referring to Figures 8 to 17, the carrying out of the method of surgical treatment according to the present invention will be described.
After having made two small anterior skin incisions in the shoulder, two cannulas, a lower one and an upper one relative to the patient's head, are introduced.
Once the two operative cannulas have been prepared and introduced, the lower capsuloplasty is performed via bone anchoring by means of a first anchor and suture wire suitable for capsulolabral tissue.
The first anchor is preferably of PushLock® type, and is preferably used with a suture wire suitable for capsular tissue, e.g. Fiberwire® wire of the Arthrex® Company.
Referring to Figure 8, the performing of the tenodesis comprises a step of making, with the aid of a bone drill, a housing for the tenodesis anchor in the scapular glenoid, preferably at 3 hours when the shoulder is right-side and at 9 hours when the shoulder is left-side (taking reference to the glenoid plane as a clock dial).
The performing of the tenodesis comprises a step of inserting the retainer through the drilling of the subscapularis tendon in order to position a portion thereof astride tissues comprised between a first and a second incision performed on the tendon.
Next Figure 9 refers to the step of inserting the retainer. Said step is carried out by inserting a central portion of the retainer through a first operative cannula, drilling the subscapularis tendon, in a way such that the free ends of the retainer remain accessible from the outside of the retainer, through the first operative cannula (lower cannula).
When the glenoid labrum is present, and when its conditions are still good, the method comprises a step of drilling the glenoid labrum, such as to allow passage of the central portion of the retainer. As shown in Figure 10, the method further comprises a step of recovering, for instance with a ring pliers, one of the free ends through the second cannula (upper cannula) so that the two free ends come out from two different cannulas.
Next Figures 1 1 and 12 illustrate instead the step of recovering the end of the tape from the upper cannula, and making the tape come out from the lower cannula so that the ends be astride drilled tissues and come out again from the same lower cannula.
Figure 13 illustrates instead the further step envisaged by the method, which provides positioning both free ends of the retainer in a slot of a tenodesis anchor.
Finally, as shown in Figures 14 to 17, the method comprises a step of introducing, via a tool for positioning and bone anchoring, the tenodesis anchor in said first cannula, concomitantly keeping in traction the free ends of the retainer, making the anchor slide along said ends, causing said ends to remain substantially parallel, until inserting and anchoring said anchor in the housing made in the scapular glenoid, so as to obtain a substantial closure of the front pocket.
Figures 18 and 19 show just a shoulder joint after the above-mentioned surgical intervention.
Finally, Figure 20 shows the same shoulder, respectively before/after having undergone eight dislocations - and after an intervention performed according to the present invention.
There are highlighted the elimination of the anterior glenohumeral pocket and the centering of the head of the humerus. Next Figure 21 refers to a further result of an intervention according to the present invention, which clearly shows the approaching of the tendon to the humeral head after fixation.
The present invention has been hereto described with reference to preferred embodiments thereof. It is understood that each of the technical solutions implemented in the preferred embodiments described herein by way of example, could advantageously be differently combined between them, to form other embodiments, all falling within the concept of the same invention and all comprised within the protective scope of the claims hereinafter.