Fig. 155.—Bilateral Pes Valgus and Hallux Valgus in a girl æt. 15, the result of Anterior Poliomyelitis.
In paralytic valgus the medial border of the foot is depressed and convex towards the sole, and although the foot can readily be restored to the normal position by manipulation, it at once resumes the valgus attitude. The leg is wasted, the skin is cold and livid, and the ankle is flail-like. The treatment consists in reinforcing the paralysed tibial muscles by attaching the peronei, or a strip of the tendo Achillis, to the scaphoid, or in bringing about an ankylosis of the joints above and in front of the talus.
Traumatic flat-foot is that form which results directly from injury. It is most often due to a fall from a height on to the feet; the ligaments supporting the arch are ruptured, and the bones are displaced, either at the time of the injury or later when the patient gets out of bed. The arch can only be restored by a wedge-resection of the tarsus. Loss of the arch may follow as a result of walking on the everted foot after injuries about the ankle, especially a badly united Pott's fracture; the foot may be displaced laterally and pronated, the sole looking laterally. This variety is very unsightly and disabling; it is treated by supra-malleolar osteotomy of the tibia and fibula.
Other Forms of Flat-foot.—Flat-foot is sometimes met with in rickety children, in association with knock-knee or curvature of the bones of the leg, and is treated on the same lines as other rickety deformities. It may follow upon an attack of acute rheumatism or upon diseases in the region of the ankle and tarsus, such as gonorrhœa, arthritis deformans, tuberculosis, and Charcot's disease; the gonorrhœal flat-foot is extremely resistant to treatment. There is a congenital form in which the sole is convex and the dorsum concave, the result of the persistence of an abnormal attitude of the fœtus in utero. Lastly, there is a racial variety, chiefly met with in the negro and in Jews, which is inherited and developmental, and which, although unsightly, is rarely a cause of disability.
Pes Transverso-planus.—Lange describes under this head a sinking or flattening of the anterior arch formed by the heads of the metatarsal bones, of which normally only the heads of the first and fifth rest on the ground. In this condition all may be on the same level or the arch is actually convex towards the sole. It may coexist along with the common form of flat-foot, or it may be associated with the neuralgic pain known as metatarsalgia.
Painful Affections of the Heel.—These include inflammation of the bursa between the posterior aspect of the calcaneus and the lower end of the tendo Achillis, inflammation of the tendon itself and its sheath of cellular tissue, and the presence of a spur of bone projecting from the plantar aspect of the tuberosity of the calcaneus. The spur of bone is the source of considerable pain on standing and walking, and tenderness is elicited on making pressure on the plantar aspect of the heel; it is well demonstrated by the X-rays ([Fig. 156]). The condition is usually bilateral. Complete relief is obtained by removing the spur by operation.
Sever of Boston calls attention to a painful condition of the heel met with in children, and associated with changes in the epiphysial junction, allied to those met with in the epiphysis of the tubercle of the tibia in Schlatter's disease. The changes in the epiphysial junction can be demonstrated in skiagrams. Treatment is conducted on the same lines as in teno-synovitis of the tendo Achillis.
Metatarsalgia.—This affection, which was first described by Morton of Philadelphia (1876), is a neuralgia on the area of the anterior metatarsal arch, specially located in the region of the heads of the third and fourth metatarsal bones. It is most often met with in adults between thirty and forty, is commoner in women than in men, and is often combined with flat-foot. The patient complains of a dull aching or of intense cramp-like pain in the anterior part of the foot. The pain is usually relieved by rest and by taking off the boot. It may be excited by pressing the heads of the metatarsals together or by grasping the fourth metatarso-phalangeal joint between the finger and thumb. In advanced cases the pain may be so severe as to cripple the patient, so that she is obliged to use a crutch. On examination, the sole may be found to be broadened across the balls of the toes, and there may be corns over the heads of the third and fourth metatarsals. Skiagrams may show a downward displacement of the head of one or other of these bones, and prints of the foot may show an increased area of contact in the region of the balls of the toes. The affection is of insidious development, and is usually ascribed to sinking of the transverse arch of the foot—pes transverso-planus—the result of weakness or of wearing badly fitting boots. The intense pain is believed to be due to stretching of, or pressure upon, the interdigital nerves or the communicating branch between the medial and lateral plantar nerves; Whitman believes it is due to abnormal side pressure on the depressed articulations.