A splint is necessary here also after reduction.
The Knee.—These dislocations are rarely complete, and are easily reduced; the lateral ones by flexing the thigh on the belly, straightening the leg, and rotating it a little from side to side.
Another Plan.—Apparatus.—Two jack towels. This is more useful when the tibia is carried backwards. Lay the patient on his back, and slip a jack towel in a clove hitch up the leg to the ham, and another round the small of the leg; the thigh is bent and retained in a semiflexed position by an assistant holding the jack towel at the ham, while a second pulls on the one at the ankle and so disengages the bones from each other, when the surgeon readily slips them into place.
After reduction is accomplished, the limb should be fixed in a leathern back splint until the inflammation subsides.
Dislocation of the Patella.—The displacement of this bone on to the outer or inner condyle is generally easily reduced if the knee is straightened and the vasti relaxed by bending the thigh on the belly. When the patella is turned on its own axis, the side, not the under surface, is locked against the condyle, and reduction is sometimes extremely difficult or impossible. The same movements must be adopted as for simple lateral displacement, and the surgeon must endeavour to release the bone by pressing its upper edge downwards with his thumbs.
After their reduction, all dislocations about the knee-joint must be treated by rest, straight splints, and evaporating lotions.
The Foot is very rarely dislocated from the leg without fracture of the malleoli. Its reduction requires simple extension of the foot on the leg, with the knee bent; the surgeon grasps the heel in one hand, the foot in the other, while an assistant fixes the thigh in the half-bent position. The foot is first drawn downwards to disengage it from the tibia, and then directed into its place.
After reduction the limb should be put in a McIntyre’s splint, in the way described for fracture of the tibia near the ankle-joint.
Scarpa’s Shoes are instruments for restoring deformed feet to their natural shape. The shoe (fig. 69) consists of a flat metal sole broader and longer than the foot, furnished with a rest for the heel. A rod, attached to the side of the sole beneath the ankle, reaches up the limb, to which it is secured by one broad band and buckle below, and by a second above the knee, opposite which joint the iron stem moves on a free joint backwards and forwards. Opposite the malleoli are set the centres of movement required for the restoration of the deformity; they are moved by a key. The foot is fastened to the sole by straps across the instep and ankle; the toes are restrained by a strap passing round them and fixed to a horizontal toe-bar by the side of the foot. In fitting one of these shoes, which of course must always be made specially for the limb it is to control, the points to be attended to are—1st, the centres of the joints must be so arranged that, when traction is made, the foot shall revolve back again round the same centres it has passed in reaching its distortion. For example, if the heel is raised, as in talipes equinus, the fore part of the sole of the shoe must be capable of elevation, by moving a joint that rotates in a plane parallel to the rotation of the astragalus on the tibia. In most cases of talipes, the bones of the foot have been displaced round several centres; hence, the apparatus must be furnished with power of traction along all of these, or along the lines resulting from these different directions acting simultaneously. 2nd. The heel must be got thoroughly into its place at the back of the sole to ensure that the foot will follow the shoe in all its movements.
The treatment of talipes frequently requires division of tendons before extension is attempted, if they are too firmly contracted to permit the bones to regain their proper position until they are lengthened by division. Thus, in varus, the tibiales and tendo achillis; in valgus, the peronci; in equinus, the tendo achillis; are often divided.