(Lord Lister"s specimen. Anatomical Museum, University of Edinburgh.)]
Secondary cancer is a comparatively common disease, and, as in metastases in other tissues, the secondary growths resemble the parent tumour. The soft forms grow rapidly, and eat away the bone, without altering its shape or form. In slowly growing forms there may be considerable formation of imperfectly formed bone, often deficient in lime salts; this condition may be widely diffused throughout the skeleton, and, as it is a.s.sociated with softening and bending of the bones, it is known as _cancerous osteomalacia_. Secondary cancer of bone is attended with pain, or it suddenly attracts notice by the occurrence of pathological fracture--as, for example, in the shaft of the femur or humerus. In the vertebrae, it is attended with a painful form of paraplegia, which may involve the lower or all four extremities. On the other hand, the disease may show itself clinically as a tumour of bone, which may attain a considerable size, and may be mistaken for a sarcoma, unless the existence of the primary cancer is discovered.
The cancers most liable to give rise to metastasis in bone are those of the breast, liver, uterus, prostate, colon, and r.e.c.t.u.m; hyper-nephroma of the kidney may also give rise to metastases in bone.
_Secondary tumours derived from the thyreoid gland_ require special mention, because they are peculiar in that neither the primary growth in the thyreoid nor the secondary growth in the bones is necessarily malignant. They are therefore amenable to operative treatment.
_Secondary sarcoma_, whether derived from a primary growth in the bone or in the soft parts, is much rarer than secondary cancer. Its removal by operation is usually contra-indicated, but we have known of cases terminating fatally in which the _section_ revealed only one metastasis, the removal of which would have benefited the patient.
In all of these conditions, examination of the bones with the X-rays gives valuable information and often disclose unsuspected metastases.
_Cancer of Bone resulting from Direct Extension from Soft Parts._--In this group there are also two clinical types. The first is met with in relation to _epithelioma of a mucous surface_--for example, the palate, tongue, gums, antrum, frontal sinus, auditory meatus, or middle ear.
They will be described under these special regions.
The second type is met with in relation to _epithelioma occurring in a sinus_, the sequel of suppurative osteomyelitis, compound fracture, or tuberculous disease. The patient has usually had a discharging sinus for a great number of years: we have known it to last as many as fifty. The epithelioma originates at the skin orifice of the sinus, and spreads to the bone and into its interior, where the progress of the cancer is resisted by dense bone, which obliterates the medullary ca.n.a.l. Although its progress is slow, the infiltration of the bone is usually more extensive than appears externally. It is recognised clinically by the characteristic cauliflower growth at the orifice of the sinus, and by the offensive nature of the discharge. A similar epithelioma may arise in connection with a _chronic ulcer of the leg_. The cancer may infect the femoral lymph glands. The operative treatment is influenced by the extent of the disease in the soft parts overlying the bone, and consists in wide removal of the diseased tissues and resection of the bone, or in amputation.
#Cysts of Bone.#--With the exception of hydatid cysts, cysts in the interior of bone are the result of the liquefaction of solid tissue; this may be that of chondroma, myeloma, or sarcoma, but more commonly of the marrow in osteomyelitis fibrosa.
CHAPTER XXI
DISEASES OF JOINTS
Definition of terms--Ankylosis. DISEASES: Errors of development--Bacterial diseases: _Pyogenic_; _Gonorrhal_; _Tuberculous_; _Syphilitic_; _Acute rheumatism_--Diseases a.s.sociated with certain const.i.tutional conditions: _Gout_; _Chronic articular rheumatism_; _Arthritis deformans_; _Haemophilia_--Diseases a.s.sociated with affections of the nervous system: _Neuro-arthropathies_; _Charcot"s disease_--Hysterical or mimetic affections of joints--Tumours and cysts--Loose bodies.
#Definition of Terms.#--The term _synovitis_ is applied to any reaction which affects the synovial membrane of a joint. It is usually a.s.sociated with effusion of fluid, and this may be serous, sero-fibrinous, or purulent. As the term synovitis merely refers to the tissue involved, it should always be used with an adjective--such as gouty, gonorrhal, or tuberculous--which indicates its pathological nature.
The terms _hydrops_, _hydrarthrosis_, and _chronic serous synovitis_ are synonymous, and are employed when a serous effusion into the joint is the prominent clinical feature. Hydrops may occur apart from disease--for example, in the knee-joint from repeated sprains, or when there is a loose body in the joint--but is met with chiefly in the chronic forms of synovitis which result from gonorrha, tuberculosis, syphilis, arthritis deformans, or arthropathies of nerve origin.
_Arthritis_ is the term applied when not only the synovial membrane but the articular surfaces, and it may be also the ends of the bones, are involved, and it is necessary to prefix a qualifying adjective which indicates its nature. When effusion is present, it may be serous, as in arthritis deformans, or sero-fibrinous or purulent, as in certain forms of pyogenic and tuberculous arthritis. Wasting of the muscles, especially the extensors, in the vicinity of the joint is a constant accompaniment of arthritis. On account of the involvement of the articular surfaces, arthritis is apt to be followed by ankylosis.
The term _empyema_ is sometimes employed to indicate that the cavity of the joint contains pus. This is observed chiefly in chronic disease of pyogenic or tuberculous origin, and is usually attended with the formation of abscesses outside the joint.
_Ulceration of cartilage_ and _caries of the articular surfaces_ are common accompaniments of the more serious and progressive forms of joint disease, especially those of bacterial origin. The destruction of cartilage may be secondary to disease of the synovial membrane or of the subjacent bone. When the disease begins as a synovitis, the synovial membrane spreads over the articular surface, fuses with the cartilage and eats into it, causing defects or holes which are spoken of as ulcers. When the disease begins in the bone, the marrow is converted into granulation tissue, which eats into the cartilage and separates it from the bone. Following on the destruction of the cartilage, the articular surface of the bone undergoes disintegration, a condition spoken of as _caries of the articular surface_. The occurrence of ulceration of cartilage and of articular caries is attended with the clinical signs of fixation of the joint from involuntary muscular contraction, wasting of muscles, and starting pains. These _starting pains_ are the result of sudden involuntary movements of the joint. They occur most frequently as the patient is dropping off to sleep; the muscles becoming relaxed, the sensitive ulcerated surfaces jar on one another, which causes sudden reflex contraction of the muscles, and the resulting movement being attended with severe pain, wakens the patient with a start. Advanced articular caries is usually a.s.sociated with some abnormal att.i.tude and with shortening of the limb. It may be possible to feel the bony surfaces grate upon one another. When all its const.i.tuent elements are damaged or destroyed, a joint is said to be _disorganised_.
Should recovery take place, repair is usually attended with union of the opposing articular surfaces either by fibrous tissue or by bone.
#Conditions of Impaired Mobility of Joints.#--There are four conditions of impaired mobility in joints: rigidity, contracture, ankylosis, and locking. _Rigidity_ is the fixation of a joint by involuntary contraction of muscles, and is of value as a sign of disease in deep-seated joints, such as the hip. It disappears under anaesthesia.
_Contracture_ is the term applied when the fixation is due to permanent shortening of the soft parts around a joint--muscles, tendons, ligaments, fasciae, or skin. As the structures on the flexor aspect are more liable to undergo such shortening, contracture is nearly always a.s.sociated with flexion. Contracture may result from disease of the joint, or from conditions outside it--for example, disease in one of the adjacent bones, or lesions of the nerves.
_Ankylosis_ is the term applied when impaired mobility results from changes involving the articular surfaces. It is frequently combined with contracture. Three anatomical varieties of ankylosis are recognised--(a) The _fibrous_, in which there are adhesions between the opposing surfaces, which may be in the form of loose isolated bands of fibrous tissue, or may bind the bones so closely together as to obliterate the cavity of the joint. The resulting stiffness, therefore, varies from a mere restriction of the normal range of movement, up to a close union of the bones which prevents movement. Fibrous ankylosis may follow upon injury, especially dislocation or fracture implicating a joint, or it may result from any form of arthritis. (b) _Cartilaginous ankylosis_ implies the fusion of two apposed cartilaginous surfaces. It is often found between the patella and the trochlear surface of the femur in tuberculous disease of the knee. The fusion of the cartilaginous surfaces is preceded by the spreading of a vascular connective tissue, derived from the synovial membrane, over the articular cartilage. Clinically, it is a.s.sociated with absolute immobility, (c) _Bony ankylosis_ or _synostosis_ is an osseous union between articulating surfaces (Figs. 154 and 155). It may follow upon fibrous or cartilaginous ankylosis, or may result from the fusion of two articular surfaces which have lost their cartilage and become covered with granulations. In the majority of cases it is to be regarded as a reparative process, presenting a.n.a.logies with the union of fracture.
[Ill.u.s.tration: FIG. 154.--Osseous Ankylosis of Femur and Tibia in position of flexion.]
The term _arthritis ossificans_ has been applied by Joseph Griffiths to a condition in which the articular surfaces become fused without evident cause.
The occurrence of ankylosis in a joint before the skeleton has attained maturity does not appear to impair the growth in length of the bones affected; ankylosis of the temporo-maxillary joints, however, greatly impairs the growth of the mandible. When there is arrest of growth accompanying ankylosis, it usually depends on changes in the ossifying junctions caused by the original disease.
To differentiate by manipulation between muscular fixation and ankylosis, it may be necessary to anaesthetise the patient. The nature and extent of ankylosis may be learned by skiagraphy; in osseous ankylosis the shadow of the two bones is a continuous one. In fibrous as contrasted with osseous ankylosis mobility may be elicited, although only to a limited extent; while in osseous ankylosis the joint is rigidly fixed, and attempts to move it are painless.
[Ill.u.s.tration: FIG. 155.--Osseous Ankylosis of Knee in the flexed position following upon Tuberculous Arthritis.
(Anatomical Museum, University of Edinburgh.)]
The _treatment_ is influenced by the nature of the original lesion, the variety of the ankylosis, and the att.i.tude of the joint. When there is restriction of movement due to fibrous adhesions, these may be elongated or ruptured. Elongation of the adhesions may be effected by manipulations, exercises, and the use of special forms of apparatus--such as the application of weights to the limb. It may be necessary to administer an anaesthetic before rupturing strong fibrous adhesions, and this procedure must be carried out with caution, in view of such risks as fracture of the bone--which is often rarefied--or separation of an epiphysis. There is also the risk of fat embolism, and of re-starting the original disease. The giving way of adhesions may be attended with an audible crack; and the procedure is often followed by considerable pain and effusion into the joint, which necessitate rest for some days before exercises and manipulations can be resumed.
_Operative treatment_ may be called for in cases in which the bones are closely bound to one another by fibrous or by osseous tissue.
_Arthrolysis_, which consists in opening the joint and dividing the fibrous adhesions, is almost inevitably followed by their reunion.
_Arthroplasty._--Murphy of Chicago devised this operation for restoring movement to an ankylosed joint. It consists in transplanting between the bones a flap of fat-bearing tissue, from which a bursal cavity lined with endothelium and containing a fluid rich in mucin is ultimately formed.
Arthroplasty is most successful in ankylosis following upon injury; when the ankylosis results from some infective condition such as tuberculosis or gonorrha, it is liable to result in failure either because of a fresh outbreak of the infection or because the ankylosis recurs.
When arthroplasty is impracticable, and a movable joint is desired--for example at the elbow--a considerable amount of bone, and it may be also of periosteum and capsular ligament, is resected to allow of the formation of a false joint.
When bony ankylosis has occurred with the joint in an undesirable att.i.tude--for example flexion at the hip or knee--it can sometimes be remedied by osteotomy or by a wedge-shaped resection of the bone, with or without such additional division of the contracted soft parts as will permit of the limb being placed in the att.i.tude desired.
Bony ankylosis of the joints of a finger, whether the result of injury or disease, is difficult to remedy by any operative procedure, for while it is possible to restore mobility, the new joint is apt to be flail-like.
_Locking._--A joint is said to lock when its movements are abruptly arrested by the coming together of bony outgrowths around the joint. It is best ill.u.s.trated in arthritis deformans of the hip in which new bone formed round the rim of the acetabulum mechanically arrests the excursions of the head of the femur. The new bone, which limits the movements, is readily demonstrated in skiagrams; it may be removed by operative means. Locking of joints is more often met with as a result of injuries, especially in fractures occurring in the region of the elbow.
In certain injuries of the semilunar menisci of the knee, also, the joint is liable to a variety of locking, which differs, however, in many respects from that described above.
#Errors of Development.#--These include congenital dislocations and other deformities of intra-uterine origin, such as abnormal laxity of joints, absence, displacement, or defective growth of one or other of the essential const.i.tuents of a joint. The more important of these are described along with the surgery of the Extremities.
DISEASES OF JOINTS
#Bacterial Diseases.#--In most bacterial diseases the organisms are carried to the joint in the blood-stream, and they lodge either in the synovial membrane or in one of the bones, whence the disease subsequently spreads to the other structures of the joint. Organisms may also be introduced through accidental wounds. It has been shown experimentally that joints are among the most susceptible parts of the body to infection, and this would appear to be due to the viscid character of the synovial fluid, which protects organisms from bactericidal agents in the tissues and fluids.
PYOGENIC DISEASES
The commoner pyogenic diseases are the result of infection of one or other of the joint structures with _staphylococci_ or _streptococci_, which may be demonstrated in the exudate in the joint and in the substance of the synovial membrane. The mode of infection is the same as in the pyogenic diseases of bone, the metastasis occurring most frequently from the mucous membrane of the pharynx (J. B. Murphy). The localisation of the infection in a particular joint is determined by injury, exposure to cold, antecedent disease of the joint, or other factors, the nature of which is not always apparent.
The effects on the joint vary in severity. In the milder forms, there is engorgement and infiltration of the synovial membrane, and an effusion into the cavity of the joint of serous fluid mixed with flakes of fibrin--_serous synovitis_. In more severe infections the exudate consists of pus mixed with fibrin, and, it may be, red blood corpuscles--_purulent_ or _suppurative synovitis_; the synovial membrane and the ligaments are softened, and the surface of the membrane presents granulations resembling those on an ulcer; foci of suppuration may develop in the peri-articular cellular tissue and result in abscesses.
In _acute arthritis_, all the structures of the joint are involved; the articular cartilage is invaded by granulation tissue derived from the synovial membrane, and from the marrow of the subjacent bone; it presents a worm-eaten or ulcerated appearance, or it may undergo necrosis and separate, exposing the subjacent bone and leading to disintegration of the osseous trabeculae--_caries_. With the destruction of the ligaments, the stability of the joint is lost, and it becomes disorganised.
The _clinical features_ vary with the extent of the infection. When this is confined to the synovial and peri-synovial tissues--_acute serous_ and _purulent synovitis_--there is the usual general reaction, a.s.sociated with pyrexia and great pain in the joint. The part is hot and swollen, the swelling a.s.suming the shape of the distended synovial sac, fluctuation can usually be elicited, and the joint is held in the flexed position.
When the joint is infected by extension from the surrounding cellular tissue, the joint lesion may not be recognised at an early stage because of the swollen condition of the limb, and because there are already symptoms of toxaemia. We have observed a case in which both the hip and knee joints were infected from the cellular tissue.
If the infection involves all the joint structures--_acute arthritis_--the general and local phenomena are intensified, the temperature rises quickly, often with a rigor, and remains high; the patient looks ill, and is either unable to sleep or the sleep is disturbed by starting pains. The joint is held rigid in the flexed position, and the least attempt at movement causes severe pain; the slightest jar--even the shaking of the bed--may cause agony. The joint is hot, tensely distended, and there may be dema of the peri-articular tissues or of the limb as a whole. If the pus perforates the joint capsule, there are signs of abscess or of diffuse suppuration in the cellular tissue. The final disorganisation of the joint is indicated by abnormal mobility and grating of the articular surfaces, or by spontaneous displacement of the bones, and this may amount to dislocation. In the acute arthritis of infants, the epiphysis concerned may be separated and displaced.
When the _joint is infected through an external wound_, the anatomical features are similar to those observed when the infection has reached the joint by the blood-stream, but the destructive changes tend to be more severe and are more likely to result in disorganisation.