—This condition is known also as talipes planus, or, more briefly, pes planus, the common names being flat-foot, splay-foot, or pronated foot. A particularly painful variety has been often spoken of as pes planus dolorosus.
This type of deformity is rarely of congenital origin. It is characterized by abduction and pronation of the foot, on whose inner border there often appear two prominences, one the head of the astragalus the other the head of the scaphoid. The bones show much less alteration in actual shape than in club-foot. The scaphoid is deflected somewhat to the outer side and the astragalus turned a little outward and downward. A prominent feature is that the arch of the foot is more or less obliterated, while its inner border becomes convex instead of remaining concave. This is due in large measure to relaxation of the ligaments binding the foot to the calcis, especially that extending from the astragalus ([Fig. 264]).
Etiology.
—The common cause of the condition is lack of sufficient strength of the parts to carry the weight of the superimposed body. It is produced often by ill-fitting shoes, accompanied by excessive strain or rapid growth and gain in weight. It is sometimes complicated by a certain shortening of the gastrocnemius (Shaffer), which prevents flexion to its complete degree and compels some degree of eversion of the foot in completing a step. In some instances it is induced by previous morbid conditions, such as rickets, paralysis, diseases of the spinal cord, and postgonorrheal arthritis. Ill-fitting footwear is the most common cause, as it compresses the front part of the foot and prevents adaptation of the foot to the position it should assume when the weight of the body is thrown upon it. The effect of this weight is to necessitate a greater divergence of the toes than such shoes permit and gradually causes the patient to walk on the inside of the foot. Flat-foot is seldom seen in those who habitually go barefooted.
The condition is best relieved by making a graphic record of each case. This is done by making the barefooted patient step first on smoked glass or on wet dusted paper, and then upon a piece of plain paper. If such a print be compared with the print similarly obtained from the normal foot it will be seen how different are the points of contact and how differently distributed is the body weight. A non-graphic but sufficient inspection may be afforded by having the patient stand upon a stool whose top is made of glass and by using a mirror beneath the feet. In any event it will be shown that the inner border of the foot is at least nearly straight or even convex, whereas it should be neither.
Fig. 264
Talipes valgus.
There are tender points over the astragaloscaphoid joints, at the base of the first and fifth metatarsals, in front of the internal malleolus, as well as often beneath the heel. Patients who thus suffer find that the feet perspire very easily. In walking the feet are everted, and when tenderness is very great it is because too much weight is borne on the inner borders of such everted feet. Inspection of the shoes will also show wearing of the inner border and over the inner malleolus.
Spontaneous cure of such cases does not occur, except perhaps after long confinement in bed from other causes, but patients occasionally become tolerant after a time, though many of them grow steadily worse and avoid using the feet more than is absolutely necessary.