The disease may last for an indefinite period, the general health remaining long unaffected. In a considerable number of the recorded cases one of the bones became the seat of sarcoma.
#Osteomyelitis Fibrosa.#--This comparatively rare disease, which was first described by Recklinghausen, presents many interesting features.
Because of its causing deformities of the bones and an undue liability to fracture, and being chiefly met with in adolescents, it is regarded by some authors as a juvenile form of Paget"s disease. It may be diffused throughout the skeleton--we have seen it in the skull and in the bones of the extremities--or it may be confined to a single bone, usually the femur, or, what is more remarkable, the condition may affect a portion only of the shaft of a long bone and be sharply defined from the normal bone in contact with it.
[Ill.u.s.tration: FIG. 136.--Osteomyelitis Fibrosa affecting Femora in a man aet. 19. The curving of the bones is due to multiple fractures.]
On longitudinal section of a long bone during the active stage of the disease, the marrow is seen to be replaced by a vascular young connective tissue which encroaches on the surrounding spongy bone, reducing it to the slenderest proportions; the formation of bone from the periosteum does not keep pace with the absorption and replacement going on in the interior, and the cortex may be reduced to a thin sh.e.l.l of imperfectly calcified bone which can be cut with a knife. The young connective tissue which replaces the marrow is not unlike that seen in osteomalacia; it is highly vascular and may show haemorrhages of various date; there are abundant giant cells of the myeloma type, and degeneration and liquefaction of tissue may result in the formation of cysts, which, when they const.i.tute a prominent feature, are responsible for the name--_osteomyelitis fibrosa cystica_--sometimes applied to the condition.
It would appear that most of the recorded cases of _cysts of bone_ owe their origin to this disease, while the abundance of giant cells with occasional islands of cartilage in the wall of such cysts is responsible for the view formerly held that they owed their origin to the liquefaction of a solid tumour, such as a myeloma, a chondroma, or even a sarcoma. Although the tissue elements in this disease resemble those of a new growth arising in the marrow, they differ in their arrangement and in their method of growth; there is no tendency to erupt through the cortex of the bone, to invade the soft parts, or to give rise to secondary growths.
_Clinical Features._--The onset of the disease is insidious, and attention is usually first directed to it by the occurrence of fracture of the shaft of one of the long bones--usually the femur--from violence that would be insufficient to break a healthy bone. Apart from fracture, the great increase in the size of one of the long bones and its uneven contour are sufficiently remarkable to suggest examination with the X-rays, by means of which the condition is at once recognised. A systematic examination of the other long bones will often reveal the presence of the disease at a stage before the bone is altered externally.
Symmetrical bossing of the skull was present in the case shown in Figs. 136 and 137, and there were also scattered patches of brown pigmentation of the skin of the face, neck, and trunk, similar to those met with in generalised neuro-fibromatosis. Apart from fracture, the disease is recognised by the thickening and usually also by the curving of the shafts of the long bones. It is easy to understand the curvature of bones that have pa.s.sed through a soft stage and also of those that have been broken and badly united, but it is difficult to account for the curvatures that have no such cause; for example, we have seen marked curve of the radius in a forearm of which the ulna was quite straight. The curvature probably resulted from exaggerated growth in length.
[Ill.u.s.tration: FIG. 137.--Radiogram of Upper End of Femur showing appearances in Osteomyelitis Fibrosa.]
The X-ray appearances vary with the stage of the malady, not estimated in time, for the condition is chronic and may become stationary, but according to whether it is progressive or undergoing repair. The shadow of the bone presents a poor contrast to the soft parts, and no trace of its original architecture; in extreme cases the shadow of the femur resembles an unevenly filled sausage (Fig. 137); there is no cortical layer, the interior shows no trabecular structure, and some of the many clear areas are probably cysts. The condition extends right up to the articular cartilage, or, in the case of adolescent bones, up to the epiphysial cartilage.
_Prognosis._--The condition does not appear to affect the general health. The future is concerned with the local conditions, and, especially in the case of the femur, with its liability to fracture; so far as we know there is no time limit to this.
_Treatment_ is confined to protecting the affected bone--usually the femur--from injury. Operative treatment may be required for lameness due to a badly united fracture.
#Neuropathic Atrophy of Bone.#--The conditions included under this heading occur in a.s.sociation with diseases of the nervous system.
Most importance attaches to the fragility of the bones met with in general paralysis of the insane, locomotor ataxia, and other chronic diseases of the brain and spinal cord. The bones are liable to be fractured by forces which would be insufficient to break a healthy bone.
In _locomotor ataxia_ the fractures affect especially the bones of the lower extremity, and may occur before there are any definite nerve symptoms, but they are more often met with in the ataxic stage, when the abrupt and uncontrolled movements of the limbs may play a part in their causation. They may be unattended with pain, and may fail to unite; when repair does take place, it is sometimes attended with an excessive formation of callus. Joint lesions of the nature of Charcot"s disease may occur simultaneously with the alterations in the bones. In _syringomyelia_ pathological fracture is not so frequent as in locomotor ataxia; it is more likely to occur in the bones of the upper extremity, and especially in the humerus. In some cases of _epilepsy_ the bones break when the patient falls in a fit, and there is usually an exaggerated amount of comminution.
In these affections the bones present no histological or chemical alterations, and the X-ray shadow does not differ from the normal. It is maintained, therefore, that the disposition to fracture does not depend upon a fragility of the bone, but on the loss of the muscular sense and of common sensation in the bones, as a result of which there is an inability properly to throw the muscles into action and dispose the limbs so as to place them under the most favourable conditions to meet external violence.
#Osteogenesis Imperfecta#, #Fragilitas Ossium#, or #Congenital Osteopsathyrosis#.--These terms are used to describe a condition in which an undue fragility of the bones dates from intra-uterine life. It may occur in several members of the same family. In severe cases, intra-uterine fractures occur, and during parturition fresh fractures are almost sure to be produced, so that at birth there is a combination of recent fractures and old fractures united and partly united, with bendings and thickenings of the bones. Large areas of the cranial vault may remain membranous.
After birth the predisposition to fracture continues, the bones are easily broken, the fractures are attended with little or no pain, the crepitus is soft, and although union may take place, it may be delayed and be attended with excess of callus. Cases have been observed in which a child has sustained over a hundred fractures.
The bones show a feeble shadow with the X-rays, and appear thin and atrophied; the medullary ca.n.a.l is increased at the expense of the cortex.
In young infants in whom multiple fractures occur the prognosis as to life is unfavourable, and no satisfactory treatment of the disease has been formulated. If the patient survives, the tendency to fracture gradually disappears.
#Hypertrophic Pulmonary Osteo-Arthropathy.#--This condition, which was described by Marie in 1890, is secondary to disease in the chest, such as chronic phthisis, empyema, bronchiectasis, or sarcoma of the lung.
There is symmetrical enlargement and deformity of the hands and feet; the shafts of the bones are thickened, and the soft tissues of the terminal segments of the digits hypertrophied. The fingers come to resemble drum-sticks, and the thumb the clapper of a bell. The nails are convex, and incurved at their free ends, suggesting a resemblance to the beak of a parrot. There is also enlargement of the lower ends of the bones of the forearm and leg, and effusion into the wrist and ankle-joints. Skiagrams of the hands and feet show a deposit of new bone along the shafts of the phalanges.
TUMOURS OF BONE
New growths which originate in the skeleton are spoken of as _primary tumours_; those which invade the bones, either by metastasis from other parts of the body or by spread from adjacent tissues, as _secondary_. A tumour of bone may grow from the cellular elements of the periosteum, the marrow, or the epiphysial cartilage.
Primary tumours are of the connective-tissue type, and are usually solitary, although certain forms, such as the chondroma, may be multiple from the outset.
_Periosteal tumours_ are at first situated on one side of the bone, but as they grow they tend to surround it completely. Innocent periosteal tumours retain the outer fibrous layer as a capsule. Malignant tumours tend to perforate the periosteal capsule and invade the soft parts.
_Central_ or _medullary tumours_ as they increase in size replace the surrounding bone, and simultaneously new bone is formed on the surface; as this is in its turn absorbed, further bone is formed beneath the periosteum, so that in time the bone is increased in girth, and is said to be "expanded" by the growth in its interior.
#Primary Tumours--Osteoma.#--When the tumour projects from the surface of a bone it is called an _exostosis_. When growing from bones developed in membrane, such as the flat bones of the skull, it is usually dense like ivory, and the term _ivory exostosis_ is employed. When derived from hyaline cartilage--for example, at the ends of the long bones--it is known as a _cartilaginous exostosis_. This is invested with a cap of cartilage from which it continues to grow until the skeleton attains maturity.
An exostosis forms a rounded or mushroom-shaped tumour of limited size, which may be either sessile or pedunculated, and its surface is smooth or nodulated (Figs. 138 and 139). A cartilaginous exostosis in the vicinity of a joint may be invested with a synovial sac or bursa--the so-called _exostosis bursata_. The bursa may be derived from the synovial membrane of the adjacent joint with which its cavity sometimes communicates, or it may be of advent.i.tious origin; when it is the seat of bursitis and becomes distended with fluid, it may mask the underlying exostosis, which then requires a radiogram for its demonstration.
[Ill.u.s.tration: FIG. 138.--Radiogram of Right Knee showing Multiple Exostoses.]
_Clinically_, the osteoma forms a hard, indolent tumour attached to a bone. The symptoms to which it gives rise depend on its situation. In the vicinity of a joint, it may interfere with movement; on the medial side of the knee it may incapacitate the patient from riding. When growing from the dorsum of the terminal phalanx of the great toe--_subungual exostosis_--it displaces the nail, and may project through its matrix at the point of the toe, while the soft parts over it may be ulcerated from pressure (Fig. 107). It incapacitates the patient from wearing a boot. When it presses on a nerve-trunk it causes pains and cramps. In the orbit it displaces the eyeball; in the nasal fossae and in the external auditory meatus it causes obstruction, which may be attended with ulceration and discharge. In the skull it may project from the outer table, forming a smooth rounded swelling, or it may project from the inner table and press upon the brain.
The diagnosis is to be made by the slow growth of the tumour, its hardness, and by the shadow which it presents with the X-rays (Fig. 138).
An osteoma which does not cause symptoms may be left alone, as it ceases to grow when the skeleton is mature and has no tendency to change its benign character. If causing symptoms, it is removed by dividing the neck or base of the tumour with a chisel, care being taken to remove the whole of the overlying cartilage. The dense varieties met with in the bones of the skull present greater difficulties; if it is necessary to remove them, the base or neck of the tumour is perforated in many directions with highly tempered drills rotated by some form of engine, and the division is completed with the chisel.
[Ill.u.s.tration: FIG. 139.--Multiple Exotoses of both limbs.
(Photograph lent by Sir George T. Beatson.)]
#Multiple Exostoses.#--This disease, which, by custom, is still placed in the category of tumours, is to be regarded as a disorder of growth, dating from intra-uterine life and probably due to a disturbance in the function of the glands of internal secretion, the thyreoid being the one which is most likely to be at fault (Arthur Keith). The disorder of growth is confined to those elements of the skeleton where a core of bone formed in cartilage comes to be encased in a sheath of bone formed beneath the periosteum. To indicate this abnormality the name _diaphysial aclasis_ has been employed by Arthur Keith at the suggestion of Morley Roberts.
Bones formed entirely in cartilage are exempt, namely, the tarsal and carpal bones, the epiphyses of the long bones, the sternum, and the bodies of the vertebrae. Bones formed entirely in membrane, that is, those of the face and of the cranial vault, are also exempt. The disorder mainly affects the ossifying junctions of the long bones of the extremities, the vertebral border of the scapula, and the cristal border of the ilium.
_Clinically_ the disease is attended with the gradual and painless development during childhood or adolescence of a number of tumours or irregular projections of bone, at the ends of the long bones, the vertebral border of the scapula, and the cristal border of the ilium.
They exhibit a rough symmetry; they rarely attain any size; and they usually cease growing when the skeleton attains maturity--the conversion of cartilage into bone being then completed. While they originate from the ossifying junctions of the long bones, they tend, as the shaft increases in length, to project from the surface of the bone at some distance from the ossifying junction and to "point" away from it. They may cause symptoms by "locking" the adjacent joint or by pressing upon nerve-trunks or blood vessels.
In a considerable proportion of cases, the disturbance of growth is further manifested by dwarfing of the long bones; these are not only deficient in length but are sometimes also curved and misshapen, which accounts for the condition being occasionally confused with the disturbances of growth resulting from rickets. In about one-third of the recorded cases there is a dislocation of the head of the radius on one or on both sides, a result of unequal growth between the bones of the forearm.
[Ill.u.s.tration: FIG. 140.--Multiple Cartilaginous Exostoses in a man aet. 27. The scapular tumour projecting above the right clavicle has taken on active growth and pressed injuriously on the cords of the brachial plexus.]
In early adult life, one of the tumours, instead of undergoing ossification, may take on active growth and exhibit the features of a chondro-sarcoma, pressing injuriously upon adjacent structures (Fig. 140) and giving rise later to metastases in the lungs.
The _X-ray appearances_ of the bones affected are of a striking character; apart from the outgrowths of bone or "tumours" there is evident a widespread alteration in the internal architecture of the bones, which suggests a.n.a.logies with other disturbances of ossification such as achondroplasia and osteomyelitis fibrosa. The condition is one that runs in families, sometimes through several generations; we have more than once seen a father and son together in the hospital waiting-room.
As regards _treatment_, there is no indication for surgical interference except when one or other tumour is a source of disability as by pressing upon a nerve-trunk or by locking a joint, in which case it is easily removed by chiselling through its neck.
[Ill.u.s.tration: FIG. 141.--Multiple Cartilaginous Exostoses in a man aet. 27, the same as in Fig. 140.]
_Diffuse Osteoma, Leontiasis Ossea._--This rare affection was described by Virchow, and named leontiasis ossea because of the disfigurement to which it gives rise. It usually commences in adolescence as a diffuse overgrowth first of one and then of both maxillae; these bones are enlarged in all directions and project on the face, and the nasal fossae and the maxillary and frontal sinuses become filled up with bone, which encroaches also on the orbital cavities. In addition to the hideous deformity, the patient suffers from blocking of the nose, loss of smell, and protrusion of the eyes, sometimes followed by loss of sight. The condition is liable to spread to the zygomatic and frontal bones, the vault of the skull, and to the mandible. The base of the skull is not affected. The disease is of slow progress and may become arrested; life may be prolonged for many years, or may be terminated by brain complications or by intercurrent affections. In certain cases it is possible to remove some of the more disfiguring of the bony ma.s.ses.
A less aggressive form, confined to the maxilla on one side, is sometimes met with, and, in a case of this variety under our own observation, the disfigurement, which was the only subject of complaint, was removed, after reflecting the soft parts, by paring away the excess of bone; this is easily done as the bone is spongy, and at an early stage, imperfectly calcified.
A remarkable form of _unilateral hypertrophy and diffuse osteoma of the skull_, following the distribution of the fifth nerve, has seen described by Jonathan Hutchinson and Alexis Thomson.
#Chondroma.#--Cartilaginous tumours, apart from those giving rise to multiple exostoses, grow from the long bones and from the scapula, ilium, ribs, or jaws. They usually project from the surface of the bone, and may attain an enormous size; sometimes they grow in the interior of a bone, the so-called _enchondroma_.
The hyaline cartilage composing the tumour frequently undergoes myxomatous degeneration, resulting in the formation of a glairy, semi-fluid jelly, and if this change takes place throughout the tumour it comes to resemble a cyst. On the other hand, the cartilage may undergo calcification or ossification. The most important transition of all is that into sarcoma, the so-called _malignant chondroma_ or _chondro-sarcoma_, which is a.s.sociated with rapid increase in size, and parts of the tumour may be carried off in the blood-stream and give rise to secondary growths, especially in the lungs.
Cases have been met with in which certain parts of the skeleton--only those developed in cartilage--were so uniformly permeated with cartilage that the condition has been described as a "chondromatosis" and is regarded as dating from an early period of ftal life. Unlike the condition known as multiple cartilaginous exostoses, it is a malignant disease.