The whole of the morbid conditions described in connection with the fingers are probably represented in the toes, and the classification adopted in the former case may be applied with but slight modification to the latter.
Lesions of the sole corresponding to Dupuytren’s disease in the hand are extremely rare, on account of the protection afforded by the shoe and the thickness of the plantar pad, and although cases have been mentioned by Mr. Adams and other surgeons, I believe none has yet been shown or discussed at any medical society. The following example deserves record:
The patient, a gardener, aged fifty-seven, was admitted to St. Thomas’s Hospital in May last with contraction of both hands. He stated that he first noticed a slight contraction beginning in the ring finger of the left hand twelve years ago; in the course of a year or two the disease extended to the little finger, and afterwards to the middle finger. Four years since a similar affection appeared in the right hand, and shortly before admission he observed a superficial nodule on the sole of each foot. He had never suffered from gout or rheumatism, and had always enjoyed good health; the family history was negative. On examination the third, fourth, and fifth fingers were found contracted in both hands; the fourth and fifth fingers of the left hand being strongly bent at the first and second joints, and brought into contact with the palm, while on the right side the lesions were similar in character but less advanced. In each sole a flat subcutaneous nodule could be felt adherent to the plantar fascia and slightly to the integument over the head of the second metatarsal bone, but there was no puckering of the skin, and the position of the toes was quite unaffected. The contracted cords in both hands were divided by multiple subcutaneous incisions, and the fingers were extended by plaster-of-Paris splints. The nodule upon the right sole was excised, and found to consist of white fibrous tissue, longitudinally striated, and adherent to the fascia, but could be detached from it without difficulty. Under the microscope the appearances presented were identical with those in the early stage of Dupuytren’s contraction, and there is no doubt that the foot nodule was pathologically the same as the contracted tissue in the hands. The operations upon the hands and feet were successful.
This group includes the conditions known as hammer toe, hallux flexus, and some of the lateral versions of the toes.
This complaint may be described as a permanent flexion from the straight line at either or both of the inter-phalangeal joints, without paralysis of muscles, unattended with any primary degenerative or inflammatory disease of the articular structures, and essentially confined in origin to the period of active growth. Some precision of definition is necessary to exclude similar deformities of wholly different pathological nature.
Hammer toe was known long before it became the subject of scientific observation. According to Dr. Cohen,[8] the first printed description was that by a French surgeon named Laforest, in a volume published in 1782, and entitled “L’Art de Soigner les Pieds”; but Laforest was the successor of one Rousselot, who thirteen years earlier wrote a book to which he gave the formidable name of “La Toilette les Pieds, ou Traité de la Guérison des Cors, Verrues, et autres Affections de la Peau, et Dissertation abrégé sur le Traitement et la Guérison des Cancers.” In this essay a flexion of the toes attributed to the use of short shoes is alluded to with sufficient clearness to make it probable that Laforest had succeeded to the ideas as well as to the practice of his predecessor. The first account, however, with any pretensions to science, was that given by Boyer in 1822.[9] Since that time the subject has been discussed repeatedly in France, and within the last few years has been brought forward twice in England, at the Clinical Society in 1887, and at the Medical Society in 1889.
The deformity is found in both sexes, but appears to be somewhat more frequent in the male (three to two). The influence of age is very strongly marked. The condition invariably begins within the developmental period, and may show itself at any time between birth and adult life, but most frequently attracts the notice of the patient for the first time during the third quinquennial period. Amongst a number of incipient cases seen at Hanwell not more than one-tenth were under twelve years of age, the little toe being usually the seat of the earlier manifestations. It is said to be occasionally congenital. So far as my own observations go, neither class, occupation, nor constitutional condition, appears to have any share in its production.
It has long been a popular as well as a medical opinion that the deformity is handed down by inheritance. Even Laforest, who contests the belief, says, “Je m’entends souvent dire que l’on est né avec un doigt ainsi; que c’est un doigt de famille.” Boyer asserted that it was frequently inherited, and Blum and others have adduced examples in support of this view. In a paper read before the Clinical Society in 1887, I referred to a history in four cases out of twenty-two which had the same bearing; and other striking examples have since been brought forward by Mr. Adams. In fact, some evidence of the influence of the hereditary principle may be traced in at least a fourth of the examples that come under notice, and is particularly frequent and clear amongst patients of the educated classes.
The subjoined pedigree of a family in which the affection has arisen, illustrates the descent through four generations. It was noted that the children attacked were those who presented most resemblance in feature and temperament to the grandfather. The deformity usually appeared about the age of four, and was confined to the second toe. “Double-jointed” thumbs were also an inheritance in the family. In another example the condition developed in five children out of eleven. Here too there was a history of “double-jointedness” in the fingers and thumb, extending through three generations; and an aunt on the male side was also the subject of hammer finger. This association of hammer toe with other developmental irregularities is significant enough to deserve attention. In addition to the instances mentioned, there are amongst the seventy-three surgical cases on my list three accompanied by hallux flexus, and one with retraction of both little toes; and there is little doubt that coincidences of a like kind would more frequently be found were it always possible to ascertain the facts by inquiry.
Seat of attack.—In surgical cases the toe most commonly affected is the second. In my list of 73 patients who had applied for treatment, this digit was affected in all but four, while the third was attacked in five, the fourth in one, and the fifth in three cases. In one instance the affection of the third toe was symmetrical, each afforded only a single example; but if all cases of contraction of the joint for 30° or more be counted without reference to symptoms, the condition is far more frequent in the little toe than in the others. Thus in an examination of a series of 800 children under sixteen years of age the little toe was found to be involved in forty-one cases, nearly all of which were double, while the second toe was affected in six only, and the third toe in five. It may be noted also that the projection of the extremity of the second toe beyond that of the first—a condition regarded as a type by the ancient sculptors—was present in only three instances. This is confirmed by Professor Flower, who failed to find a single instance in many hundreds of children.
The deformity is bilateral and symmetrical in nearly a third of the cases, in the rest having a slight preference for the right side, in the proportion of five to four. It is usually localised in the first inter-phalangeal articulation, but occasionally implicates both inter-phalangeal joints, or the distal joint only.
Symptoms.—The stages of the deformity in a typical case may be described as follows: In the first period, which is rarely seen by the surgeon, the toe is slightly extended at the metatarso-phalangeal articulation, and flexed at the proximal inter-phalangeal joint. By passive movement the flexed joint may often, but not always, be extended; but the range of motion, even in the early stage, is found to be less than that of the neighbouring or opposite toe. The distal joint is usually unaffected, and may be held straight or slightly flexed, but occasionally it undergoes contraction, either alone or in association with the proximal articulation. There is no evidence at this or any subsequent time of inflammation in or around the joint structures, except in association with corns or bursæ. How long this period may last it is difficult to say, as it may altogether escape the notice of the patient. In the second stage the flexion of the inter-phalangeal joint becomes more pronounced, and the secondary extension at the metatarso-phalangeal joint increases pari passu. At this period the affected articulation is fixed for all movement of extension, but the power of flexion within the limits left to it remains unimpaired; in other words, the angle may be diminished, but not widened, and the toe, although contracted, is neither ankylosed nor paralysed. In exceptional instances the flexion may be overcome by strong passive force, and a distinct trigger-like action established, the middle phalanx becoming extended and flexed again with a movement very comparable to that which takes place during the opening and shutting of the blade of a pocket-knife. As secondary results of the contraction of the proximal inter-phalangeal joint the patient is subject to certain inconveniences which may give rise to much suffering, and are usually the immediate cause of his appeal to the surgeon. The chief of these are a bursal formation, which is very liable to inflammation, over the angle of flexion, and two associated callosities, one above the head of the retracted phalanx, the other beneath the head of the metatarsal bone, both consequent upon the pressure exercised by the boot. (See Fig. 10.) A third callosity may develop over the tip of the toe, and the soft parts over the terminal joint may become somewhat swollen, so that the digit presents a clubbed appearance. The degree of interference with functions and comfort varies greatly in different cases, partly in relation to the degree of the contraction and partly to the sensibility of the patient. In some persons a hammer toe of a marked kind will cause so little trouble that no medical advice is sought—this is especially the case when the contraction is limited to the little toe; in others the suffering is so great that the patient begs the surgeon to remove the offending member with the knife, and remains absolutely crippled until an operation is practised for his relief. When the deformity affects more than a single digit, an interval varying from a few months to five or six years may elapse before the second attack appears. As a rule, it is the corresponding toe on the opposite foot that suffers, but occasionally a neighbour is selected; or even the distal joint of the same or another toe.
Fig. 10.
A. Diagram showing position of bones in hammer toe, involving the proximal joint; 1. Metatarsal bone; 2. Head of first phalanx; slight groove corresponding to position of dorsal border of base of second phalanx; 3,4, and 5. Callosities due to boot pressure; 6. Bursa over contracted joint; 7, 8. Shoe. The arrow indicates the direction in which the pressure of the upper leather tends to force downwards the head of the metatarsal bone towards the sole. B. Dissection of first inter-phalangeal joint in hammer toe; C. The same preparation after section of plantar fibres of lateral ligaments.
Morbid anatomy and pathology.—The earlier opinions upon the pathology of hammer toe were very conflicting. Gosselin, who dissected a specimen, was unable to find any lesion. Fano, in 1855, mentions as the chief defect a cartilaginous nucleus in the extensor tendon. Blum described a luxation of the first phalangeal joint, with a thickening of the whole capsule, and maintained that the contraction of the toe was due to a peri-arthritis set up by the inflammation resulting from corns—a curious example of “hysteron proteron.” Blandin attributed the affection to a shortening of the plantar fascia; Boyer to a retraction of the extensor tendons; Roche and Sanson to a contraction of the flexor tendons, and other surgeons to a paralysis of the interossei, but no attempt was made to separate true hammer toe from the arthritic and traumatic deformities which simulate it. It is now beyond doubt that the essential seat of the contraction is in the joint itself. The specimen represented in B, C, Fig. 10, is one prepared by myself in 1882 from a toe which had been amputated by a colleague. It showed that the deformity was not affected by section of the tendons, but that it yielded immediately upon division of the plantar fibres of the lateral ligaments where they blended with the glenoid plate. This observation, which has been confirmed by a dissection of Mr. Walsham’s, was not published until 1887, and it was by Mr. Shattock, who, working independently, had found the same lesion, that the condition was first made known at the Clinical Society in the same year. The preparation illustrating his paper is now in the museum of St. Thomas’s Hospital, as well as a second dissection demonstrating the absence of disease in the interossei. The results of these and later investigations may now be stated.
(1) There are no essential alterations of muscle or tendon except those secondary to the contraction of the joint—namely, an undue tension and prominence of the extensor tendon over the metatarso-phalangeal articulation, and an adaptive deficiency of length in the flexors, which are prevented by the permanently bent state of the articulation from keeping pace in growth with the osseous structures. (2) The skin and fasciæ in like manner are unaffected or only undergo a secondary shortening on the flexor side in severe and long-standing cases. (3) The articular surfaces generally show no change beyond atrophy of that portion of the cartilage of the head of the proximal bone, which is permanently excluded from contact with the distal bone in consequence of the imperfect range of extension of the joint. In some cases, however, a distinct transverse groove is present on the head of the proximal phalanx at the point where it comes in contact with the dorsal border of the base of the distal bone during the attempt at extension, and behind this groove the bone may be heaped up into a little ridge. It is the existence of this irregularity that explains the trigger phenomenon previously alluded to. (4) The ligaments present no structural change, but an important quantitative defect is always found in the plantar fibres of the lateral ligaments, which are so short that they check prematurely the movement of extension of the joint.
The real origin of the articular defect has been the source of much argument. At all times, whatever may have been the opinion as to the exact morbid anatomy of the condition, there has been a strong disposition to blame the shoemaker, or rather the fashion that dictated the arbitrary form the shoe was to assume, as the prime cause of the disease. There is, of course, no question that the mistaken ideal of elegance which finds expression in the demand for tight and pointed boots has been the cause of much misery and deformity, and it appears only natural to assume that the artificial crowding together of the toes might force one of the members to assume a position of retraction, in order to make room for the rest, and the digit so drawn up might after a time become permanently fixed in its abnormal attitude. This view is well expressed by Mr. Ellis,[10] but the study of a number of cases of hammer toe furnishes strong reason for doubting this fatally plausible hypothesis. The deformity may be seen in early infancy, before any rigid foot covering has been adopted; and a precisely analogous condition is known to exist in the fingers, which are not subjected to any artificial restraints. Moreover, in the great majority of the feet affected with hammer toe there is a complete freedom from the deformities which are known to result from overcrowding of the digits, and there is seldom anything in the history of the cases to indicate the past use of improper boots.
It has been said that hammer toe is unknown in countries where boots are not worn; but the subject has yet to be studied in those parts of the world on a scale that sanctions generalisation. Moreover, as hammer toe is painful only in consequence of the friction and pressure induced by the foot-covering, its existence would be unlikely to attract much attention in a bootless race. During my own residence of six years in Japan I never met with an example, and my friend Surgeon-General Takaki writes to me that his observations, covering a period of fifteen years, are equally negative; but it must be noted that it is the rising and boot-wearing generation that has been especially brought under our notice, and the conclusions to be drawn from our experience tend as much to contradict the view that boots are an immediate cause of hammer toe, as to support the belief that the Japanese are exempt from the defect. There is little doubt, however, that the use of shoes is to some extent, and in a remote sense, a predisponent to this and to other analogous deformities, for it is certain that a rigid leather foot-covering, even when shaped according to the most scientific principles, must necessarily impede the free action of the toes, and so interfere with the processes of nutrition and development; but I am equally confident that few, if any, of the examples of hammer toe that have come within my own experience could be traced to any special defect in the form of the shoe. Out of the whole number only six confessed to having worn tight boots. In the rest, neither history nor inspection indicated any fault of the kind, and the feet in the great majority were perfectly well formed in all other respects, and bore no marks of injurious compression. In a case of inherited hammer toe in which the proximal joint of the second digit of the right foot was straightened by operation, the boots worn before and after the operation were made upon sound anatomical principles; but nevertheless the patient came two years later with a contraction of the distal joint of the same toe and of the middle toe of the opposite foot, and a lateral distortion of the fourth toe.
The pathological explanation I believe to be that advanced to account for the occurrence of hammer finder. The examination of a large number of healthy feet will reveal physiological variations in the condition of the inter-phalangeal joints exactly comparable with those noted in the hands. The second phalanx may in some persons be super-extended 30° beyond the axial line of the proximal bone, while in other instances the movement is arrested by tension of the plantar fibres of the lateral ligaments before this line has been attained;[11] and in the distal joint even greater variation may be found. There is, in fact, a physiological tendency to hammer toe in large numbers of people who never actually suffer any inconvenience from it, and it is in the exaggeration of this physiological irregularity that we have to seek the pathology of the surgical hammer toe. The tendency ceases at adult life, because the ligamentous and bony structures of the articulation have then assumed their permanent condition, and any later deformity simulating it can only occur as a result of a totally different set of conditions.
Hammer toe, then, like hammer finger, must be regarded as the result of inadequate longitudinal evolution of the ligaments which limit the movement of extension at the inter-phalangeal joints, and the symptoms induced by the deformity are mainly dependent upon the formation of callosities and bursæ by contact with the opposed hard surfaces of the foot covering. This irregularity of development may be either inherited or accidental.
Treatment.—It is probably not within our power to prevent the occurrence of hammer toe, even by the greatest care in the selection of boots. For its relief when developed many plans have been adopted, the chief of which are as follow:
1. Extension by splints of various kinds in the early stages, while the contraction may be overcome by passive force. The condition is rarely seen by the surgeon in this period, but should it fall under observation the persevering use of passive extension is preferable. When the deformity is well marked, splints are painful and useless.
2. Tenotomy of the extensor tendon (Boyer). This measure, which was doubtless suggested by the visible tension of the tendon in many cases, is more likely to aggravate than to relieve the symptoms.
3. Tenotomy of the flexor tendons. This to be successful must involve also the section of the glenoid and lateral ligaments. Such an operation has been practised both by the subcutaneous and by the open methods, but it involves the risk of division of the plantar digital nerves, and the necessity for a prolonged after-treatment to prevent recurrence. It has even been advised by Petersen to treat the contraction by a transverse incision, through integuments, tendons, and ligaments, down to the articulation, but the promptitude of the method is its sole recommendation.
4. Subcutaneous division of the lateral ligaments has been performed with good results by Mr. Adams, but it has the disadvantage of requiring a long after-treatment.
5. Resection of the joint. This is unquestionably the most eligible measure, and has been successfully practised on different plans by various surgeons during the last twelve years or more, both in England and France. The articular extremities of both bones may be removed or the head of the proximal bone only, the distal bone being left intact. In either case the toe is subsequently fixed for a period of three or four weeks in an extended position. The procedure I have found most speedy and satisfactory is as follows: An incision is made on the lateral aspect of the affected articulation, following the axis of the bones and exposing the lateral ligament, while leaving intact the vascular and nervous trunks. The ligament is then divided, by a touch of the knife, and by a forcible lateral movement the head of the proximal phalanx is made to protrude through the wound, and is removed with a pair of bone nippers. The toe is straightened, the wound closed by sutures (without drainage), and dressed. Antiseptic precautions must be strictly observed, and the operation must not be performed until all inflammatory signs have been removed from the superjacent corn. The operation can be completed within two or three minutes, and, what is a far more important consideration, it involves the least possible interference with the structures of the toe. The wound heals by first intention, and after a fortnight’s rest the patient is able to walk, the toe being extended for a few weeks upon a dorsal splint of flat steel, such as was used in making the now obsolete appendages to the back of the feminine skirt. The result is all that could be desired, and the relief immediate and permanent. The same operation is applicable for the distal joint, but is less easy.
6. Amputation was, until within the last ten or twelve years, the usual resource after the failure of tenotomy of the extensor. It affords a curious comment upon the surgery of the pre-antiseptic period that the chief reason given against this operation by the early writers was its danger to life. At the present time it can rarely be needed unless, by any accident, the antisepsis of the resection operation fails and acute inflammation sets in. The objections to it are the mutilation, and the tendency to lateral distortion of the adjacent toes to fill the gap left by the lost member.
Hallux flexus appears to have been first recognised as a separate affection only a few years ago, in 1887, and it is to Mr. Davies-Colley that we are indebted for the name and for the earliest discussion of the characters and causation of the disease. It is stated, however, by Blum that Nélaton described a “cou de cygne” of the great toe, and attributed it to the use of short boots. I have been unable to discover the reference in the works of this surgeon, but if the citation can be verified, the credit of recognising the existence and nature of the deformity will fall to him, for there is no doubt that hallux flexus is pathologically a “cou de cygne” or hammer toe. Since Mr. Davies-Colley’s introduction of the subject various contributions have been made, by Mr. Howard Marsh, Mr. Reginald Lucy, Mr. Cotterell, Mr. Ellis, and others, and I must draw especial attention to a valuable analysis of thirteen cases by my colleague, Mr. Makins, in the St. Thomas’s Hospital Reports for 1888. The complaint is by no means a rare one, for since 1887, when I began to take notes of all the cases that were brought under my observation in private and hospital practice, I have accumulated a list of thirty examples of what may be termed true “hallux flexus,” besides a number of contractions presenting a superficial resemblance to it, but resulting from arthritic lesions. I propose, as in the case of hammer toe, to separate these latter entirely from the former, because the pathological, and even the clinical, distinctions between the two classes are perfectly well marked, and it hence can only mislead to place them in the same category.
Hallux flexus may be defined as a progressive diminution of the normal range of extension at the metatarso-phalangeal, or, more rarely, at the inter-phalangeal joint of the great toe. It is unassociated with any disease of the bones, cartilages, or synovial membrane of the articulation, and originates only during the period of active growth. It is, in fact, a “hammer great toe,” and it will be found strictly analogous to the disease just described, occurring under the same conditions and affecting the corresponding articulations.[12] The name proposed by Mr. Davies-Colley has been objected to on more grounds than one. In the first place, there is perhaps a lack of soundness in the pedigree of the word “hallux.” It is a rather modern addition to anatomical nomenclature, and its sanction in classical literature is very dubious. In Plautus there is an expression “hallex viri,” implying a little man, a “thumbling,” and the words “hallex,” “allex,” and “hallux” have been used by other writers with a somewhat questionable signification for the great toe. A purist might indeed be justified in opposing the adoption of either “hallex” or “hallux,” and especially the latter; but the convenience attached to a distinctive name for the great toe in place of that of “pollex,” which is applied also to the thumb, is so great that we are not tempted to be hypercritical on philological grounds. A more serious objection has been raised against the adjective “flexus,” because in the majority of cases the toe is not actually in the position of flexion; but the term “flexion” may be applied in the sense of movement as well as in that of position; and although the great toe in hallux flexus may not reach the position of flexion, it has passed through the motion of flexion before it has attained the line of direction in which it is found in the disease.
Symptoms.—In a typical case of hallux flexus the patient, usually a boy near the age of puberty, suffers some little pain about the metatarso-phalangeal articulation of the great toe in walking, at the moment when the weight of the body falls chiefly upon this joint. Rest affords complete relief, and the structures about the articulation show no signs of inflammation. As time goes on the pain increases and becomes associated with a sense of rigidity of the toe, and the power of full extension becomes lost. The diminution of the range of movement is very gradual, and usually it is not until the proximal phalanx can no longer be extended beyond a line corresponding to the prolonged axis of the metatarsal bone that the condition is brought before the surgeon, but in more extreme examples the toe becomes actually bent below this axis, so that it forms with the metatarsal bone an obtuse angle with plantar opening. The foot is now seriously crippled. Over-use in walking induces much suffering, and any attempt at passive extension is extremely painful, while flexion still remains unimpaired. The head of the metatarsal bone thrown into prominence by the unwonted position of the proximal phalanx looks abnormally large. In some cases a reflex hyperæmia of the tissues surrounding the joint may be induced by forced exercise; but there is rarely, if ever, any effusion within the capsule. The patient finds walking more and more difficult, and to avoid pressure upon the contracted articulation limps on the outer edge of the foot; but this gives little relief, and at last he is compelled to rest. In the more severe cases the patient consults the surgeon; in the slighter forms he puts up with the inconvenience, and we may assume that he recovers without professional assistance, for the condition is very seldom found after the attainment of full adult life.
An analysis of my series of thirty cases shows that the deformity is much more frequent in boys the number including only three girls. (In the series of thirteen cases recorded by Mr. Makins the proportion of males to females was eleven to two). It was bilateral in one case only, right-sided in nineteen cases, left in ten, and affected the metatarso-phalangeal articulation in every instance, except two in which the distal joint was involved. (Fig. 11.) In only three cases did the flexion pass the prolonged axis of the metatarsal bone, the angle reached in the worst example being 150°; in the rest the toe during full extension was either in a line with the metatarsal bone, or formed with the latter a very obtuse angle, 170° to 160°, with the opening towards the dorsal aspect. The ages at which the symptoms were first noticed ranged from twelve to eighteen, in the greater number lying between fourteen and sixteen. The associated deformities were: excessive length of toe in two cases, this amounting to a distinct giant growth in one, hammer toe (second) in one, hallux valgus (slight) in three, flat-foot in four, and slight varus in one. In the other cases the feet were perfectly normal in shape. The duration of the disease before the patient came under treatment varied from three months to four years. Occupation appeared to exercise little influence; the subjects were mostly schoolboys, labourers, and errand boys, but there was no reason to believe that there had been any unusual strain upon the powers of endurance, except in two instances. In two cases the condition was attributed to the use of short boots, but in the others no complaint was made as to the foot covering, and that in wear at the time of attendance was as unobjectionable as the materials and plan of the modern boot will allow. Constitutionally, the patients were, for the most part, a little below the average in physique; one (a girl) was tuberculous, and one was a child of rheumatic parents, but none had suffered from rheumatism. The result of inquiries with respect to inherited tendencies was less striking than in the case of hammer toe. In one instance the father had double hammer toe, in another a brother had suffered from hallux flexus at the age of sixteen, and became cured without medical intervention in the course of three years; but in the majority no satisfactory information on the point could be obtained.
Fig. 11.
Hallux flexus of the distal joint.
Progress.—There can be little doubt that the natural tendency of the complaint is to subside under the mechanical influence of ordinary exercise, and hence, although the deformity is fairly common in youth, it is rarely found in fully developed adults, except where the distal joint is affected. In one case of this kind the contraction began about puberty, and was still present at the age of fifty-two, but the defect never interfered materially with locomotion. It is possible that some of the ordinary cases terminate, as suggested by Mr. Davies-Colley, by conversion into hallux valgus, but my inquiries have failed to confirm this.
Pathology.—The origin of the condition may be explained in the same manner as that of hammer finger and hammer toe. There is a physiological variation in the range of movement permitted in the articulations of the great toe similar to that demonstrated in the fingers and lesser toes, and in examining a number of healthy feet it will be found that the position of extreme super-extension at the metatarso-phalangeal joint may lie at any point between 30° and 110° beyond the prolonged axis of the metatarsal bone; but if the movement of extension be checked at less than 30°, the symptoms of hallux flexus supervene. The chief distinctive feature in the anatomy of the joint lies in the substitution of two sesamoid bones, with their tendons and connecting tissue, for the glenoid plate developed in all the other articulations, and it is those structures that receive the distal attachment of the plantar fibres of the lateral ligaments. (Figs. 12 and 13.) The function of the lateral ligaments, however, remains the same as in the other toes, and the range of the movement of extension is governed by the development of their plantar fibres.
Fig. 12.
Bones and ligaments in hallux flexus. 1. Lateral ligament of metatarso-phalangeal joint; inferior fibres attached to sesamoid bone; 2. Lateral ligament of inter-phalangeal joint; inferior fibres blending with glenoid plate.
Fig. 13.
Hallux flexus of the distal joint.
The opportunities of examining the morbid anatomy of the complaint are necessarily very few. Mr. Davies-Colley’s specimen proves that the structures restraining the movement of extension correspond to those concerned in the production of hammer toe, those fibres of the lateral ligaments which blend with the osseo-tendinous structures replacing the glenoid plate; and the cause of the deformity in both cases appears to be an irregularity of nutrition by which the ligamentous fibres undergo imperfect longitudinal development, and consequently induce premature arrest of the movement of extension. This developmental defect is probably unconnected with any special error in the form of the shoe. Like hammer toe, the deformity occurs at the age most prone to nutritive disturbance; but hallux flexus tends to undergo cure without the help of the surgeon, because the weight of the body serves as an extending force, which sooner or later proves stronger than the resistance opposed; while in hammer toe the lesser digit is not essential to locomotion, and its retraction at the metatarso-phalangeal joint frees the inter-phalangeal joint from all necessity for action, and favours the permanency of the vicious position.
Hallux flexus of the distal joint must be distinguished from the paralytic hallux retractus which simulates it (see p. 127).
Treatment.—Bearing in mind the fact that true hallux flexus has a natural tendency to recovery, it is obvious that the graver surgical operations can seldom be called for. In the case of hammer toe a resection of the articulation may be undertaken without hesitation, because the deformity is more likely to become aggravated than relieved by lapse of time, and because the function of the digit is not sensibly interfered with by obliteration of the joint; but the destruction of the metatarso-phalangeal joint of the great toe entails a permanent alteration of gait. The treatment I have adopted in the milder cases is to instruct the patient to perform a regulated series of passive movements of the toe by the use of his hands, aiding the process by massage of the lower and inner side of the foot, and as the tenderness passes away to practise walking on tiptoe until the normal degree of extension is restored. In more severe examples I have extended the joint forcibly under an anæsthetic, afterwards fixing it in the super-extended position in a plaster splint for three weeks. The result of this plan has been so satisfactory that I have found it unnecessary to do more, but should it fail, we have the choice of several plans: (1) Section of the lateral ligaments, subcutaneously or by means of an open wound. (2) Excision of the head of the metatarsal bone, an operation necessarily involving obliteration of the joint and a shifting of the point of support to the distal joint, which is less well fitted to discharge the office. It might, however, be permissible in certain cases. (3) Excision of the proximal half of the first phalanx. This has been successfully effected by Mr. Davies-Colley. (4) Osteotomy of the metatarsal bone above the head, with excision of a dorsal wedge proportioned to allow the toe to be placed in a position of slight super-extension, the articulation being preserved intact.
It is improbable that any of these more severe measures will be required if the method of forcible reposition be well carried out.
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.
2. Forcible rectification under an anæsthetic is satisfactory for slighter cases. It may be aided if necessary by subcutaneous section of the opposing tendinous and ligamentous structures on the tibular side, and the toe is fixed for two or three weeks in plaster of Paris. The rectification should be preserved by the use of properly constructed shoes with a septum between the first and second toes, when the patient begins to walk.
3. Resection of the joint is undoubtedly the best operation in the more severe operations of hallux valgus. Involving the obliteration of an important articulation, it was feared that it might induce serious crippling, but the plan has been adopted with perfect success by Mr. Clutton[14] who, excising the cartilaginous extremities of the bones and fixing the shafts in suitable position by means of an ivory peg, has secured the best results. During the last two years I have applied the principle of the operation recommended for hammer toe. Excision of the head of the metatarsal bone is performed through a longitudinal incision over the inner side of the joint, the toe is then replaced and fixed for three weeks in a slightly extended position by means of plaster of Paris. The success of these measures is far more complete than could have been anticipated on theoretical grounds. The distal joint appears to replace almost perfectly that which is lost, and the locomotion is easy and unfatiguing. In a case of my own the patient was able to walk twenty miles a day within three months of the operation.