Reinforcing Element For Muscles

Abstract

A reinforcing element for connection to a muscle to add pulling power to the muscle. An elongated elastic body member has a head end provided with means for anchoring the same to a portion of a muscle, and an opposite tail end portion having transverse openings for reception of a suture whereby the tail end portion is sewn to the muscle in longitudinally spaced relation to the anchoring means on the head end portion.

Description

BACKGROUND OF THE INVENTION

In the correction of imbalance or inequality of operation of muscles of a given related pair or group thereof, surgery is often performed to strengthen the weaker muscle of the pair or group so that the strengthened muscle exerts tension on an element controlled thereby equal to that exerted by its related muscle on its respective element. This is often done in the correction of strabismus or other deviations from the normal cooperating movements or positions of a person's eyes.

Several surgical procedures for correcting imbalance in oculorotary muscles are presently known, such as resection, recession, tucking, and tenotomy. In resection, a weak or underactive muscle is tightened by resecting a section of the muscle. In recession, an eye muscle is removed from its insertion in the eyeball and reinserted further back on the eyeball or glove. In tucking, a portion of the muscle is folded back on itself and, in a tenotomy, the tendon of a muscle is severed either partially or completely at its insertion on the globe and permitted to slide relative to the globe. While correction is obtained by one or more of these procedures, often several operations are necessary to obtain proper correction, due to difficulty in determining the right amount of tension to be applied to a muscle for the necessary correction. Such plural surgery results in an undue amount of scar tissue, and in substantial alteration of normal anatomy of the eye and the extraocular eye muscles.

SUMMARY OF THE INVENTION

The primary object of this invention is the provision of means for attachment to a muscle to implement the power exerted thereby in moving an element connected thereto.

Another important object of this invention is the provision of a reinforcing element which may be attached to spaced portions of a muscle with a minimum of surgery and minimum disturbance to the adjacent anatomy.

The reinforcing element of this invention may be used to reinforce or aid in the pulling power of substantially any one of a person's voluntary muscles, but is particularly adapted for use with extraocular or oculorotary muscles, which impart movements to the eyes and eyelids. Inasmuch as a person's eyes normally move simultaneously in various directions, any abnormality in operation of one or more muscles associated with one of the eyes creates any one or more heterophoric or heterotropic conditions. A common one of these conditions is strabismus or crossed eyes, which not only is apt to have a psychologically disturbing effect on a patient, but also seriously impairs the normal vision of the patient.

The reinforcing element of this invention comprises an elongated elastic body member having a generally arrow shaped head end portion and an opposite transversely enlarged generally flat tail end portion. The head end portion is formed to provide a plurality of spaced tooth elements which project angularly outwardly and rearwardly in the direction of the tail end portion, the tail end portion having a plurality of suture receiving openings extending transversely therethrough. When used to reinforce an extra-ocular muscle, such as one of the rectus muscles, the reinforcing element is moved head end first generally rearwardly through a suitable incision in the conjunctiva and Tenon's capsule, along the muscle and inside the muscle sheath until the head end portion is disposed near the apex of the recti at the rear end portion of the orbital cavity. Reverse movement of the body member will cause the tooth elements to become anchored in the muscle sheath and surrounding tissue, and hold the body member against withdrawal. The body member is then stretched to provide a predetermined tensile force, after which the tail end portion is sewn to the muscle adjacent its connection to the eyeball or globe. The body member, being under predetermined tension, aids the adjacent muscle to pull the eyeball or globe to its correct position.

The head end portion has forwardly converging side edges which define barbs for engagement with body or muscle tissue, the barbs cooperating with the tooth elements to anchor the head end portion against removal from the body. The head end portion is automatically anchored in an area where stitching the same to the muscle could be done only under extreme difficulty, and the tail end portion is advantageously anchored by sutures at the region of easy accessibility.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary generally vertical section of an orbit or eye receiving cavity in a human skull with an eye supported therein and the reinforcing element of this invention applied to one of the oculorotary muscles of the eye, some parts being broken away and some parts being shown in section;

FIG. 2 is an enlarged generally horizontal section taken substantially on the line 2--2 of FIG. 1;

FIG. 3 is an enlarged view in plan of the reinforcing element of this invention;

FIG. 4 is a view as seen from the line 4--4 of FIG. 3; and

FIG. 5 is a still further enlarged fragmentary detail as seen substantially from the line 5--5 of FIG. 4.

DETAILED DESCRIPTION

In FIGS. 1 and 2, skull or bone structure 1 is shown as defining a cavity 2, commonly known as an orbit, which contains the orb or eyeball, indicated generally at 3. The orb 3 is shown as being partially surrounded and supported by a cushion of fatty tissue 4, movements of the orb 3 being controlled by the oculorotary muscles, such as the recti and oblique muscles. In FIG. 1, the superior rectus muscle is indicated at 5, the inferior rectus at 6, the lateral rectus at 7, the inferior oblique at 8, and the superior oblique at 9. In FIG. 2, a medial rectus is indicated at 10, the optic nerve at 11, leading from the orb 3 rearwardly toward the juncture or apex of most of the oculorotary muscles, commonly known as the annulus of Zinn, indicated at 12 in FIG. 1. The capsule of Tenon is shown partly in section in FIG. 2, and is indicated at 13, the muscle sheath of the various oculorotary muscles being indicated at 14. In addition to the above described muscles, a levator muscle 15, for the upper eyelid, is shown in FIG. 1.

As above indicated, if any one or a given plurality of muscles of locomotion of either eye is either weaker or stronger than the corresponding muscles of the other eye, a muscle imbalance results and the patient suffers from a deviation from correction vision. Correction of the imbalance is usually effected by one of the above described surgical procedures.

The reinforcing element of this invention, indicated in its entirety at 16, is preferably made from an elastic rubberlike substance which is inert to the human body. One such substance is manufactured and sold by a Dow Corning Corp. of Midland, Michigan under the trademark "SILASTIC" (medical grade). The element 16, otherwise designated as an eye muscle spring, comprises an elongated body portion having an enlarged generally pointed head end portion 18 at one end and an enlarged tail end portion 19 at its opposite end. With reference to FIGS. 3 and 4, it will be seen that the head and tail end portions 18 and 19 are of considerably greater thickness and width than the body portion 17, so as to have greater stiffness and greater resistance to stretching than the body portion 17. As shown, the body portion 17, and said head and tail end portions 18 and 19 respectively, have opposite generally flat surfaces, the head end portion 18 having side edges converging forwardly to a substantially sharp point 20, the side edges being serrated to provide a plurality of rearwardly pointed barbs or teeth 21. As shown in FIG. 3, the maximum width of the head end portion 18 is substantially greater than that of the body portion or member 17. Further, as is shown in FIG. 4, the top surface of the body portion 17 may be coplanar with the top surfaces of the head and tail end portions 18 and 19 respectively, if desired. The head end portion 18 is formed to provide a plurality of openings 22 therethrough and a like plurality of barbs 23 that project angularly outwardly and toward the tail end portion 19, see particularly FIGS. 3 and 4.

The tail end portion 19 has opposite side edges formed to provide barbs or teeth 24 that are pointed generally toward the head end portion 18, see particularly FIG. 3. Forwardly of the barbs or teeth 24, the opposite side edges of the tail end portion 19 are recurved, as indicated at 25, to be tangent to the adjacent side edges of the tail end portion 19 and body portion 17, as clearly shown in FIG. 3. Intermediate its side edges, the tail end portion 19 is provided with a plurality of longitudinally extending rows of openings 26 therethrough for reception of sutures or like devices by means of which the tail end portion may be secured to an adjacent portion of muscle or other tissue.

An example of the use to which the reinforcing element of this invention is particularly adapted, is shown in FIGS. 1 and 2, for the purpose of correcting strabismus or crossed eyes. Assuming that the lateral rectus 7 of the orb 3 is weaker than the medial rectus 10, so that the orb 3 deviates laterally inwardly, the reinforcing element 16 is applied to the lateral rectus 7 to strengthen the same or aid in its pulling power to correct the deviation. In applying the reinforcing element or eye muscle spring 16 to the lateral rectus 7, a transverse slit or incision 27 is made through the capsule of Tenon 13 or sheath 14 adjacent the frontal end of the muscle 7. Although not shown, it will be understood that the incision 27 is made through the adjacent portion of the conjunctiva, the incision being made after the eye has been prepared surgically in the usual manner. The reinforcing element or eye muscle spring 16 is then inserted through the incision 27 and, with the use of appropriate forceps or other instrument, is slid rearwardly between the muscle 7 and its sheath 14 until the head end 18 is disposed adjacent the rear end of the muscle 7 or the annulus of Zinn 12. A slight forward pull on the element 16 will then cause the teeth 21 and barbs 23 to become embedded or fixed in the surrounding tissue. Next, two or more sutures are placed or stitched to the muscle 7 shortly behind where it is affixed to the orb 3. With the use of a tension gauge, not shown, forward pull is then exerted on the tail end portion 19 of the element 16 until the element 16 is under the desired amount of tension to produce the required amount of correctional deviation to the orb or eyeball 3. While holding the reinforcing element 16 under the required tension, the sutures are brought through adjacent ones of the openings 26 in the tail end portion 19, and tied. The tied sutures are indicated at 28 in FIGS. 1 and 2. The barbs or teeth 24 engage adjacent tissue and aid the sutures 28 in holding the element 15 under proper tension. After the tail end portion 19 is thus anchored in place, any excess material thereof between the sutures 28 and the free end of the tail end portion 19 may be cut away and removed. The incision 27 and the adjacent slit portion of the conjunctiva would then be closed in the usual manner, thus burying the element or eye muscle spring 16 within the sheath of the muscle 7. When this operation is performed on an adult person under local anesthesia, it is possible to evaluate the amount of correction necessary before tying the sutures and removing the excess portion of the element 16. When the operation is performed under general anesthesia, in the case of children, a sufficient part of the tail end portion 19 may be left for subsequent surgical correction, if necessary. If adjustment is required, it is a relatively simple matter to reopen the incision 27 and replace the sutures 28 in other ones of the openings 26, so that the element 16 is placed under less or greater tension, as needed.

From the above, it can be appreciated that, with the use of my reinforcing or tension element 16, corrections of muscle imbalance in various ocular muscles may be corrected with more highly simplified surgical procedure, with a minimum of trauma and with a minumum of alteration of the normal anatomy of the extraocular eye muscles. While I have shown the reinforcing element 16 as being applied to implanted in a lateral rectus muscle, it will be appreciated that the same can be effectively applied to any of the other oculorotary muscles including the levator muscle 15 for the correction of ptosis, or drooping of the upper eyelid. As the element 16 remains within the muscle, fibrous or scar tissue grows into the openings 22 associated with the bars or teeth 23, as well as into the unsutured openings 26, thus more completely and permanently anchoring the head and tail end portions 18 and 19 of the reinforcing element, so as to aid in effecting a substantially permanent repair of the muscle.

It will be further appreciated that, while I have shown and described the reinforcing element of this invention as being associated with ocular muscles, the same can be used for joining or reinforcing other muscles as well, wherein at least a portion of the muscle is not otherwise easily accessible.

Claims

What is claimed is:

1. A reinforcing element for muscles comprising, an elongated elastic body member having generally flat opposite head and tail end portions for face-to-face engagement with longitudinally spaced portions of a muscle, and tooth elements on said head end portion for anchoring engagement with an adjacent portion of the muscle, different ones of said tooth elements projecting angularly outwardly and rearwardly in the direction of the tail end portion from opposite surfaces of said generally flat head end portion, said tail end portion having suture receiving openings therethrough whereby said tail end portion may be sewn to the muscle in longitudinally spaced relation to said head end portion.

2. The reinforcing element according to claim 1 in which said head end portion is generally arrowhead shaped in outline, having side edges converging forwardly to a substantially sharp point, said side edges defining barbs for engagement with body tissue to limit movement of said head end portion rearwardly toward said tail end portion, the maximum width of said head end portion being greater than that of said body member intermediate said head and tail end portions.

3. The reinforcing element according to claim 2 in which said tail end portion is of substantially greater width than said body member intermediate said end portions, said tail end portion defining side edges having parallel rear portions and smoothly recurving portions tangent to said rear portions and adjacent side edges of said body member.

4. The reinforcing element according to claim 1 in which said head and tail end portions are of greater width than that of said body member between said portions, said suture receiving openings being arranged in a plurality of rows, said rows extending longitudinally of said element.

5. The reinforcing element according to claim 1 in which said body member and the head and tail end portions thereof comprises a single piece of elastic material, said body member intermeditate said head and tail end portions having a smaller cross-sectional area than either of said head and tail end portions, whereby to be more easily stretched than said head and tail end portions longitudinally of said element.