Orthopedic Redressment Splint

The present invention relates to an orthopedic redressment splint for correction the adduction of the forefoot and the metatarsus with an anterior half sole enclosing the deformed foot portion at least laterally and a posterior half sole which half soles are flexibly and swivelably interconnected a vertical to the half sole plane defined by means of a pivot pin and which are provided with a spring, whose elastic force acts in the lateral direction upon the anterior half sole.

Said redressment splint, which is also designated as apes adductus splint, is employed especially for the treatment of the congenital or acquired pes adductus in infants. In an early treatment stage one frequently succeeds in bringing the foot into a normal position by means of said splints alone. In the case of serious deformities or in later treatment stages, it is possible to also make use of the pes adductus splint after an operation of the foot in a supportive manner. If the forefoot adduction is part of a club foot deformity which, inter alia, is accompanied with a pronation of the heel bone, the redressment splint has to be connected to a calf guide means and a knee bending fixation means in order to render a treatment of the club foot possible in a promising manner. However, with regard to the construction of the redressment splint, no fundamental difference exists. The deformity of the foot which is amenable to treatment with said redressment splint may consist in the deformation of the first metatarsal which deviates toward medial, while the other four metatarsals proceed normally, or in a medial deviation of all five metatarsal bones, the typical pes adductus.

In the redressment splints known according to the state of the art as are described, inter alia, in the EP 0 027 762, the pivot pin is located on the medial half shell side, while on the opposite side a spiral spring acts upon the two half soles in such a way that the medially deviating foot portions are pressed laterally. The following disadvantages result herefrom. As already mentioned in the foregoing, pes adductus splints are frequently employed with infants whose bones of the foot still are in the growing stage. Due to the pivot pin arrangement on the medial side, this side is unavoidably subjected to a strong compression. Depending on the tension of the spiral spring, the big toe is strongly compressed. Increasing from medial to lateral, a powerful compression of the tarsus is brought about.

That is why it is the object of the present invention to improve the redressment splint described in the beginning in such a way that, with a redesigned splint, a reduced compression exists on the lateral side.

This technical problem is solved by the orthopedic redressment splint described in claim 1, whose characteristic feature according to the invention consists in that the pivot is disposed on the external edge of the two half soles, thus laterally, and in that the spring used is a pressure spring which compressively loads the half soles relative to each other on the medial side.

By the dislocation of the swivel joint onto the lateral side, this side is significantly relieved of the compression which, according to the state of the art, existed in the constructions known up until now according to the state of the art. The tarsal bones remain relieved to large extent. At the same time, the position of the point of rotation on the lateral side has a straightening-out effect on the foot.

Further developments of the invention are described in claims 2 through 19.

Thus the pivot pin is preferably located at the level where the condyle of the fifth tarsal bone is articulated. An optimal application of pressure on the forefoot is ensured by this.

For the purpose of a simple construction, the two half soles are each provided on their outside with an extension, in which case the extensions overlap each other and are penetrated by the pivoting pin. In addition, by preference, at a distance from the pivoting pin in the direction of the inner edge, on each of the two half soles, prepared pivotal points for the pressure spring are to be found which are located in particular within the area of the inner edge of the half sole. It is possible, however, for more than two pivotal points to be prepared, for example, in order to displace the spring for constructional reasons from the medial side toward the center. However, in doing this, regard will have to be had that the lever arm is shortened in a corresponding manner.

In principle, no restriction exists with regard to the type of spring used. However, in a further development of the invention, a spiral spring is made use of, whose legs, at the end, lie essentially parallel to the outer edge of the half sole.

According to a further embodiment of the invention, the half soles are in each case provided with an angular section of non-resilient material, the angular sections being in each case swivelably retained at the end by the pivot pin and their free ends being located in the direction of the inner edge and reaching up to the same. These angular sections which may e.g. be comprised of metal, possess in each case prepared pivotal points for the pressure spring. This type of construction has the advantage that especially the shell-shaped foot-pad areas of the half soles may be comprised of a material capable of adapting to the shape of the foot under pressure.

According to a further embodiment of the invention, provision is made for the redressment splint to be constructed in the form of a shoe or boot portion, as is described in principle in the EP 0 027 762.

Embodiment examples of the invention are depicted in the drawings. Thus:

FIGS. 1 and 2 each show in principle representations of redressment splints with different pressure springs.

The redressment splint comprises an anterior half sole 10 and a posterior half sole 11, which are interconnected with the aid of a swivel joint 12. The swivel joint 12 comprises a pivot pin 13 which penetrates respective, mutually overlapping extensions of the anterior and posterior half sole. These extensions form part of respective angular sections 14 and 15 with prepared pivotal points 16 for a pressure spring 17 (FIG. 1) or 18 (FIG. 2).

The invention comprises the construction arrangement of the pivotal point being located on the outer edge, the lateral side, of the half soles 10 and 11. In the non-loaded state, the half soles assume the position depicted with full lines. When subjected to a load, the pressure springs 17 or 18, respectively, the anterior half sole swivels through an angle to the lateral, whereby a pertinent pressure is exerted upon the forefoot.

In the embodiment according to FIG. 1, the elongated pressure spring 17 lies essentially parallel to and within the area of the inner edge of the half soles 10 and 11, while the pressure spring 17 is in each case secured to the free ends of the angular sections 14 and 15.

In the embodiment according to FIG. 2, the pressure spring 18 is comprised of a spiral spring whose free resilient ends 18a and 18b act upon the sides of the angular sections 14 and 15 within the lateral area. The remaining part of the pressure spring 18 is disposed medially about the pivot pin 13.

As results from a comparison between the contour of the anterior half sole drawn in full lines and the "swiveled" contour shown in dashed lines, when the springs 17 and 18 exert pressure, the anterior half sole is drawn "toward the front", whereby the foot is more or less pulled lengthwise and a correction of the adduction position is encouraged to a significant degree.