This, the most common of all digital deformities, may be defined as an eversion of the great toe at the metatarso-phalangeal joint, and in some instances of the phalangeal joint also, with alterations, adaptive or causative, in the bony and ligamentous apparatus of the articulation. It is often accompanied by deformities of the other toes and by flat foot. In its milder forms it must be regarded as a simple malposition caused by the use of boots constructed on the principle of median symmetry; and as this fault is more common in the shoes made for women than in those worn by men, the distortion is far more frequent in the latter sex. In a large number of patients examined by Dr. Robinson and myself in the female wards of the Mile End Infirmary, over ten per cent. were found to be affected in greater or less degree; while in the male wards the proportion did not exceed three per cent. It is a noteworthy fact that the deformity is comparatively rare in the period before puberty. I was able to find only three examples, and these of a very slight kind, among 800 children under the age of sixteen; while incipient hammer toes and hammer fingers were present in considerable numbers. This early immunity is probably due to the fact that the vanity which leads the adolescent to sacrifice comfort to a false elegance has not awakened in the child. The more severe cases of hallux valgus in which the toe is so far everted as to form an angle of from 120° to 90° with the metatarsal bone are comparatively rare, the total number amongst 2600 persons amounting to no more than thirty (twelve male and eighteen female). It is with these that we are especially concerned, and it is probable that they are closely related in origin to hallux flexus.
Morbid anatomy.—On examining a well-marked hallux valgus it is seen that the facetted surface of the head of the metatarsal bone has been extended considerably over the external aspect, the prominent inner side of the head lies beneath the stretched joint capsule, the sesamoid bones are displaced outwards from their normal grooves, the internal lateral ligament is greatly elongated and considerably thickened, the external ligament undergoes an inversely proportionate shortening and opposes the reposition of the displaced phalanx ([Fig. 14]); and the cartilage over the portion of the joint surface, removed from its normal contact with the opposed bones, presents marked degenerative changes. The integumentary structures over the projecting head of the metatarsal bone are affected in the same way as those over the angle of flexion in hammer toe, as a consequence of friction by contact with the shoe leather; callosities and bursal formations, often of great size, are found, and inflammation of the abnormal bursa may give rise to great suffering.
Fig. 14.
Hallux valgus. From a preparation at St. Thomas’s Hospital.
A. Dorsal aspect.—1. Metatarsal bone; 2. Elongated and thickened internal lateral ligament, a large bursa lay over this; 3. First phalanx; 4. Shortened external lateral ligament; 5. Displaced external sesamoid bone.
B. Plantar aspect.—1. Metatarsal bone; 2. Degenerating cartilage over disused sesamoid furrow; 3. Displaced internal sesamoid bone; 4. Section of thickened capsule (the structure had here assumed the character of a glenoid ligament); 5. First phalanx; 6. Displaced external sesamoid bone.
Although the great majority of cases of hallux valgus are undoubtedly provoked by ill-shaped boots, it is probable that some, and especially those of a very aggravated type, are, like hallux flexus and hammer toe, dependent essentially upon causes not obviously connected with any vice in the foot covering. It is at least certain that some examples of extreme deformity are confined to one foot, the opposite member being of normal shape—a fact that strongly negatives the boot theory; and there are also bilateral cases in which the form of the distortion and the history given by the patients and friends make it equally difficult to accept the common explanation. In one instance recently under my notice the first, second, and third toes of the left foot were carried outwards over the fourth, producing a deformity of a strongly marked kind, while the right foot was perfectly well formed, and the patient, an intelligent woman, insisted that “the toes went wrong by themselves while she was growing up,” and that her shoes had nothing to do with it. In some cases the conditions may be traced to paralytic or spastic affections, and if we accept the developmental theory with respect to hammer toe and hallux flexus, we may assume that hallux valgus occasionally arises in the same way.
Treatment.—Hallux valgus, like hammer toe, is often rather a question of æsthetics than of pain or inconvenience, and the patients are only moved to see the surgeon by a natural desire to get rid of a deformity; but in many cases the inflammatory complications occuring in connection with the associated “bunion,” or the interference with the neighbouring toes, upon whose territory the larger digit is encroaching, may give rise to actual and even intolerable suffering. In the milder examples the use of a well-shaped boot, and a stocking made with a separate pocket for the great toe, as recommended by Mr. Ellis, will be sufficient to allow the rectification of the defect, and to these elementary measures may be superadded Bigg’s bunion spring, which can be obtained from most instrument makers, or a vertical septum may be introduced into the boot in the normal position of the cleft between the first and second toes. In the more severe cases these plans of treatment are insufficient, and we then have the choice of several alternatives.
1. Section of the neck of the metatarsal bone with excision of a cuneiform segment from the tibial side has been performed successfully by Mr. A. E. Barker.[13] This allows the articulation, together with the entire toe, to be restored to the straight line, but the abnormal disposition of the articular surfaces and ligaments remains uncorrected, and there is reason to fear that trouble would arise later.