Manual of Surgery/Chapter XVIII

CHAPTER XVIII

THE MUSCLES, TENDONS, AND TENDON SHEATHS

INJURIES: _Contusion_; _Sprain_; _Rupture_--Hernia of

   muscle--Dislocation of tendons--Wounds--Avulsion of tendon.
   DISEASES OF MUSCLE AND OF TENDONS: _Atrophy_; _"Muscular
   rheumatism"_--_Fibrositis_; _Contracture_; _Myositis_;
   _Calcification and Ossification_; _Tumours_. DISEASES OF TENDON
   SHEATHS: _Teno-synovitis_.

INJURIES

1. Contusion of Muscle.#--Contusion of muscle, which consists in bruising

of its fibres and blood vessels, may be due to violence acting from without, as in a blow, a kick, or a fall; or from within, as by the displacement of bone in a fracture or dislocation.

The symptoms are those common to all contusions, and the patient complains of severe pain on attempting to use the muscle, and maintains an attitude which relaxes it. If the sheath of the muscle also is torn, there is subcutaneous ecchymosis, and the accumulation of blood may result in the formation of a haematoma.

Restoration of function is usually complete; but when the nerve supplying the muscle is bruised at the same time, as may occur in the deltoid, wasting and loss of function may be persistent. In exceptional cases the process of repair may be attended with the formation of bone in the substance of the muscle, and this may likewise impair its function.

A contused muscle should be placed at rest and supported by cotton wool and a bandage; after an interval, massage and appropriate exercises are employed.

1. Sprain and Partial Rupture of Muscle.#--This lesion consists in

overstretching and partial rupture of the fibres of a muscle or its aponeurosis. It is of common occurrence in athletes and in those who follow laborious occupations. It may follow upon a single or repeated effort--especially in those who are out of training. Familiar examples of muscular sprain are the "labourer's" or "golfer's back," affecting the latissimus dorsi or the sacrospinalis (erector spinae); the "tennis-player's elbow," and the "sculler's sprain," affecting the muscles and ligaments about the elbow; the "angler's elbow," affecting the common origin of the extensors and supinators; the "sprinter's sprain," affecting the flexors of the hip; and the "jumper's and dancer's sprain," affecting the muscles of the calf. The patient complains of pain, often sudden in onset, of tenderness on pressure, and of inability to carry out the particular movement by which the sprain was produced. The disability varies in different cases, and it may incapacitate the patient from following his occupation or sport for weeks or, if imperfectly treated, even for months.

The _treatment_ consists in resting the muscle from the particular effort concerned in the production of the sprain, in gently exercising it in other directions, in the use of massage, and the induction of hyperaemia by means of heat. In neglected cases, that is, where the muscle has not been exercised, the patient shrinks from using it and the disablement threatens to be permanent; it is sometimes said that adhesions have formed and that these interfere with the recovery of function. The condition may be overcome by graduated movements or by a sudden forcible movement under an anaesthetic. These cases afford a fruitful field for the bone-setter.

1. Rupture of Muscle or Tendon.#--A muscle or a tendon may be ruptured in

its continuity or torn from its attachment to bone. The site of rupture in individual muscles is remarkably constant, and is usually at the junction of the muscular and tendinous portions. When rupture takes place through the belly of a muscle, the ends retract, the amount of retraction depending on the length of the muscle, and the extent of its attachment to adjacent aponeurosis or bone. The biceps in the arm, and the sartorius in the thigh, furnish examples of muscles in which the separation between the ends may be considerable.

The gap in the muscle becomes filled with blood, and this in time is replaced by connective tissue, which forms a bond of union between the ends. When the space is considerable the connecting medium consists of fibrous tissue, but when the ends are in contact it contains a number of newly formed muscle fibres. In the process of repair, one or both ends of the muscle or tendon may become fixed by adhesions to adjacent structures, and if the distal portion of a muscle is deprived of its nerve supply it may undergo degeneration and so have its function impaired.

Rupture of a muscle or tendon is usually the result of a sudden, and often involuntary, movement. As examples may be cited the rupture of the quadriceps extensor in attempting to regain the balance when falling backwards; of the gastrocnemius, plantaris, or tendo-calcaneus in jumping or dancing; of the adductors of the thigh in gripping a horse when it swerves--"rider's sprain"; of the abdominal muscles in vomiting, and of the biceps in sudden movements of the arm. Sometimes the effort is one that would scarcely be thought likely to rupture a muscle, as in the case recorded by Pagenstecher, where a professional athlete, while sitting at table, ruptured his biceps in a sudden effort to catch a falling glass. It would appear that the rupture is brought about not so much by the contraction of the muscle concerned, as by the contraction of the antagonistic muscles taking place before that of the muscle which undergoes rupture is completed. The violent muscular contractions of epilepsy, tetanus, or delirium rarely cause rupture.

The _clinical features_ are usually characteristic. The patient experiences a sudden pain, with the sensation of being struck with a whip, and of something giving way; sometimes a distant snap is heard. The limb becomes powerless. At the seat of rupture there is tenderness and swelling, and there may be ecchymosis. As the swelling subsides, a gap may be felt between the retracted ends, and this becomes wider when the muscle is thrown into contraction. If untreated, a hard, fibrous cord remains at the seat of rupture.

_Treatment._--The ends are approximated by placing the limb in an attitude which relaxes the muscle, and the position is maintained by bandages, splints, or special apparatus. When it is impossible thus to approximate the ends satisfactorily, the muscle or tendon is exposed by incision, and the ends brought into accurate contact by catgut sutures. This operation of primary suture yields the most satisfactory results, and is most successful when it is done within five or six days of the accident. Secondary suture after an interval of months is rendered difficult by the retraction of the ends and by their adhesion to adjacent structures.

_Rupture of the biceps of the arm_ may involve the long or the short head, or the belly of the muscle. Most interest attaches to rupture of the long tendon of origin. There is pain and tenderness in front of the upper end of the humerus, the patient is unable to abduct or to elevate the arm, and he may be unable to flex the elbow when the forearm is supinated. The long axis of the muscle, instead of being parallel with the humerus, inclines downwards and outwards. When the patient is asked to contract the muscle, its belly is seen to be drawn towards the elbow.

The _adductor longus_ may be ruptured, or torn from the pubes, by a violent effort to adduct the limb. A swelling forms in the upper and medial part of the thigh, which becomes smaller and harder when the muscle is thrown into contraction.

The _quadriceps femoris_ is usually ruptured close to its insertion into the patella, in the attempt to avoid falling backwards. The injury is sometimes bilateral. The injured limb is rendered useless for progression, as it suddenly gives way whenever the knee is flexed. Treatment is conducted on the same lines as in transverse fracture of the patella; in the majority of cases the continuity of the quadriceps should be re-established by suture within five or six days of the accident.

The _tendo calcaneus_ (Achillis) is comparatively easily ruptured, and the symptoms are sometimes so slight that the nature of the injury may be overlooked. The limb should be put up with the knee flexed and the toes pointed. This may be effected by attaching one end of an elastic band to the heel of a slipper, and securing the other to the lower third of the thigh. If this is not sufficient to bring the ends into apposition they should be approximated by an open operation.

The _plantaris_ is not infrequently ruptured from trivial causes, such as a sudden movement in boxing, tennis, or hockey. A sharp stinging pain like the stroke of a whip is felt in the calf; there is marked tenderness at the seat of rupture, and the patient is unable to raise the heel without pain. The injury is of little importance, and if the patient does not raise the heel from the ground in walking, it is recovered from in a couple of weeks or so, without it being necessary to lay him up.

1. Hernia of Muscle.#--This is a rare condition, in which, owing to the

fascia covering a muscle becoming stretched or torn, the muscular substance is protruded through the rent. It has been observed chiefly in the adductor longus. An oval swelling forms in the upper part of the thigh, is soft and prominent when the muscle is relaxed, less prominent when it is passively extended, and disappears when the muscle is thrown into contraction. It is liable to be mistaken, according to its situation, for a tumour, a cyst, a pouched vein, or a femoral or obturator hernia. Treatment is only called for when it is causing inconvenience, the muscle being exposed by a suitable incision, the herniated portion excised, and the rent in the sheath closed by sutures.

1. Dislocation of Tendons.#--Tendons which run in grooves may be displaced

as a result of rupture of the confining sheath. This injury is met with chiefly in the tendons at the ankle and in the long tendon of the biceps.

Dislocation of the _peronei tendons_ may occur, for example, from a violent twist of the foot. There is severe pain and considerable swelling on the lateral aspect of the ankle; the peroneus longus by itself, or together with the brevis, can be felt on the lateral aspect or in front of the lateral malleolus; the patient is unable to move the foot. By a little manipulation the tendons are replaced in their grooves, and are retained there by a series of strips of plaster. At the end of three weeks massage and exercises are employed.

In other cases there is no history of injury, but whenever the foot is everted the tendon of the peroneus longus is liable to be jerked forwards out of its groove, sometimes with an audible snap. The patient suffers pain and is disabled until the tendon is replaced. Reduction is easy, but as the displacement tends to recur, an operation is required to fix the tendon in its place. An incision is made over the tendon; if the sheath is slack or torn, it is tightened up or closed with catgut sutures; or an artificial sheath is made by raising up a quadrilateral flap of periosteum from the lateral aspect of the fibula, and stitching it over the tendon.

Similarly the _tibialis posterior_ may be displaced over the medial malleolus as a result of inversion of the foot.

The _long tendon of the biceps_ may be dislocated laterally--or more frequently medially--as a result of violent or repeated rotation movements of the arm, such as are performed in wringing clothes. The patient is aware of the displacement taking place, and is unable to extend the forearm until the displaced tendon has been reduced by abducting the arm. In recurrent cases the patient may be able to dislocate the tendon at will, but the disability is so inconsiderable that there is rarely any occasion for interference.

1. Wounds of Muscles and Tendons.#--When a muscle is cut across in a

wound, its ends should be brought together with sutures. If the ends are allowed to retract, and especially if the wound suppurates, they become united by scar tissue and fixed to bone or other adjacent structure. In a limb this interferes with the functions of the muscle; in the abdominal wall the scar tissue may stretch, and so favour the development of a ventral hernia.

Tendons may be cut across accidentally, especially in those wounds so commonly met with above the wrist as a result, for example, of the hand being thrust through a pane of glass. It is essential that the ends should be sutured to each other, and as the proximal end is retracted the original wound may require to be enlarged in an upward direction. When primary suture has been omitted, or has failed in consequence of suppuration, the separated ends of the tendon become adherent to adjacent structures, and the function of the associated muscle is impaired or lost. Under these conditions the operation of secondary suture is indicated.

A free incision is necessary to discover and isolate the ends of the tendon; if the interval is too wide to admit of their being approximated by sutures, means must be taken to lengthen the tendon, or one from some other part may be inserted in the gap. A new sheath may be provided for the tendon by resecting a portion of the great saphenous vein.

_Injuries of the tendons of the fingers_ are comparatively common. One of the best known is the partial or complete rupture of the aponeurosis of the extensor tendon close to its insertion into the terminal phalanx--_drop-_ or _mallet-finger_. This may result from comparatively slight violence, such as striking the tip of the extended finger against an object, or the violence may be more severe, as in attempting to catch a cricket ball or in falling. The terminal phalanx is flexed towards the palm and the patient is unable to extend it. The treatment consists in putting up the finger with the middle joint strongly flexed. In neglected cases, a perfect functional result can only be obtained by operation; under a local anaesthetic, the ruptured tendon is exposed and is sutured to the base of the phalanx, which may be drilled for the passage of the sutures.

_Subcutaneous rupture_ of one or other _of the digital tendons_ in the hand or at the wrist can be remedied only by operation. When some time has elapsed since the accident, the proximal end may be so retracted that it cannot be brought down into contact with the distal end, in which case a slip may be taken from an adjacent tendon; in the case of one of the extensors of the thumb, the extensor carpi radialis longus may be detached from its insertion and stitched to the distal end of the tendon of the thumb.

Subcutaneous _rupture of the tendon of the extensor pollicis longus_ at the wrist takes place just after its emergence from beneath the annular ligament; the actual rupture may occur painlessly, more frequently a sharp pain is felt over the back of the wrist. The prominence of the tendon, which normally forms the ulnar border of the snuff-box, disappears. This lesion is chiefly met with in drummer-boys and is the cause of drummer's palsy. The only chance of restoring function is in uniting the ruptured tendon by open operation.

[Illustration: FIG. 108.--Avulsion of Tendon with Terminal Phalanx of Thumb.

(Surgical Museum, University of Edinburgh.)]

_Avulsion of Tendons._--This is a rare injury, in which the tendons of a finger or toe are torn from their attachments along with a portion of the digit concerned. In the hand, it is usually brought about by the fingers being caught in the reins of a runaway horse, or being seized in a horse's teeth, or in machinery. It is usually the terminal phalanx that is separated, and with it the tendon of the deep flexor, which ruptures at its junction with the belly of the muscle (Fig. 108). The treatment consists in disinfecting the wound, closing the tendon-sheath, and trimming the mutilated finger so as to provide a useful stump.

DISEASES OF MUSCLES AND TENDONS

_Congenital absence_ of muscles is sometimes met with, usually in association with other deformities. The pectoralis major, for example, may be absent on one or on both sides, without, however, causing any disability, as other muscles enlarge and take on its functions.

_Atrophy of Muscle._--Simple atrophy, in which the muscle elements are merely diminished in size without undergoing any structural alteration, is commonly met with as a result of disuse, as when a patient is confined to bed for a long period.

In cases of joint disease, the muscles acting on the joint become atrophied more rapidly than is accounted for by disuse alone, and this is attributed to an interference with the trophic innervation of the muscles reflected from centres in the spinal medulla. It is more marked in the extensor than in the flexor groups of muscles. Those affected become soft and flaccid, exhibit tremors on attempted movement, and their excitability to the faradic current is diminished.

_Neuropathic atrophy_ is associated with lesions of the nervous system. It is most pronounced in lesions of the motor nerve-trunks, probably because vaso-motor and trophic fibres are involved as well as those that are purely motor in function. It is attended with definite structural alterations, the muscle elements first undergoing fatty degeneration, and then being absorbed, and replaced to a large extent by ordinary connective tissue and fat. At a certain stage the muscles exhibit the reaction of degeneration. In the common form of paralysis resulting from poliomyelitis, many fibres undergo fatty degeneration and are replaced by fat, while at the same time there is a regeneration of muscle fibres.

1. Fibrositis# or "#Muscular Rheumatism#."--This clinical term is applied

to a group of affections of which lumbago is the best-known example. The group includes lumbago, stiff-neck, and pleurodynia--conditions which have this in common, that sudden and severe pain is excited by movement of the affected part. The lesion consists in inflammatory hyperplasia of the connective tissue; the new tissue differs from normal fibrous tissue in its tendency to contract, in being swollen, painful and tender on pressure, and in the fact that it can be massaged away (Stockman). It would appear to involve mainly the fibrous tissue of muscles, although it may extend from this to aponeuroses, ligaments, periosteum, and the sheaths of nerves. The term _fibrositis_ was applied to it by Gowers in 1904.

In _lumbago_--_lumbo-sacral fibrositis_--the pain is usually located over the sacrum, the sacro-iliac joint, or the aponeurosis of the lumbar muscles on one or both sides. The amount of tenderness varies, and so long as the patient is still he is free from pain. The slightest attempt to alter his position, however, is attended by pain, which may be so severe as to render him helpless for the moment. The pain is most marked on rising from the stooping or sitting posture, and may extend down the back of the hip, especially if, as is commonly the case, lumbago and gluteal fibrosis coexist. Once a patient has suffered from lumbago, it is liable to recur, and an attack may be determined by errors of diet, changes of weather, exposure to cold or unwonted exertion. It is met with chiefly in male adults, and is most apt to occur in those who are gouty or are the subjects of oxaluric dyspepsia.

_Gluteal fibrositis_ usually follows exposure to wet, and affects the gluteal muscles, particularly the medius, and their aponeurotic coverings. When the condition has lasted for some time, indurated strands or nodules can be detected on palpating the relaxed muscles. The patient complains of persistent aching and stiffness over the buttock, and sometimes extending down the lateral aspect of the thigh. The pain is aggravated by such movements as bring the affected muscles into action. It is not referred to the line of the sciatic nerve, nor is there tenderness on pressing over the nerve, or sensations of tingling or numbness in the leg or foot.

If untreated, the morbid process may implicate the sheath of the sciatic nerve and cause genuine sciatic neuralgia (Llewellyn and Jones). A similar condition may implicate the fascia lata of the thigh, or the calf muscles and their aponeuroses--_crural fibrositis_.

In _painful stiff-neck_, or "rheumatic torticollis," the pain is located in one side of the neck, and is excited by some inadvertent movement. The head is held stiffly on one side as in wry-neck, the patient contracting the sterno-mastoid. There may be tenderness over the vertebral spines or in the lines of the cervical nerves, and the sterno-mastoid may undergo atrophy. This affection is more often met with in children.

In _pleurodynia_--_intercostal fibrositis_--the pain is in the line of the intercostal nerves, and is excited by movement of the chest, as in coughing, or by any bodily exertion. There is often marked tenderness.

A similar affection is met with in the _shoulder and arm_--_brachial fibrositis_--especially on waking from sleep. There is acute pain on attempting to abduct the arm, and there may be localised tenderness in the region of the axillary nerve.

_Treatment._--The general treatment is concerned with the diet, attention to the stomach, bowels, and kidneys and with the correction of any gouty tendencies that may be present. Remedies such as salicylates are given for the relief of pain, and for this purpose drugs of the aspirin type are to be preferred, and these may be followed by large doses of iodide of potassium. Great benefit is derived from massage, and from the induction of hyperaemia by means of heat. Cupping or needling, or, in exceptional cases, hypodermic injections of antipyrin or morphin, may be called for. To prevent relapses of lumbago, the patient must take systematic exercises of all kinds, especially such as bring out the movements of the vertebral column and hip-joints.

[Illustration: FIG. 109.--Volkmann's Ischaemic Contracture. When the wrist is flexed to a right angle it is possible to extend the fingers.

(Photographs lent by Mr. Lawford Knaggs)]

1. Contracture of Muscles.#--Permanent shortening of muscles results from

the prolonged approximation of their points of attachment, or from structural changes in their substance produced by injury or by disease. It is a frequent accompaniment and sometimes a cause of deformities, in the treatment of which lengthening of the shortened muscles or their tendons may be an essential step.

1. Myositis.#--_Ischaemic Myositis._--Volkmann was the first to describe a

form of myositis followed by contracture, resulting from interference with the arterial blood supply. It is most frequently observed in the flexor muscles of the forearm in children and young persons under treatment for fractures in the region of the elbow, the splints and bandages causing compression of the blood vessels. There is considerable effusion of blood, the skin is tense, and the muscles, vessels, and nerves are compressed; this is further increased if the elbow is flexed and splints and tight bandages are applied. The muscles acquire a board-like hardness and no longer contract under the will, and passive motion is painful and restricted. Slight contracture of the fingers is usually the first sign of the malady; in time the muscles undergo further contraction, and this brings about a claw-like deformity of the hand. The affected muscles usually show the reaction of degeneration. In severe cases the median and ulnar nerves are also the seat of cicatricial changes (ischaemic neuritis).

By means of splints, the interphalangeal, metacarpo-phalangeal, and wrist joints should be gradually extended until the deformity is over-corrected (R. Jones). Murphy advises resection of the radius and ulna sufficient to admit of dorsiflexion of the joints and lengthening of the flexor tendons.

Various forms of _pyogenic_ infection are met with in muscle, most frequently in relation to pyaemia and to typhoid fever. These may result in overgrowth of the connective-tissue framework of the muscle and degeneration of its fibres, or in suppuration and the formation of one or more abscesses in the muscle substance. Repair may be associated with contracture.

A _gonorrhoeal_ form of myositis is sometimes met with; it is painful, but rarely goes on to suppuration.

In the early secondary period of _syphilis_, the muscles may be the seat of dull, aching, nocturnal pains, especially in the neck and back. _Syphilitic contracture_ is a condition which has been observed chiefly in the later secondary period; the biceps of the arm and the hamstrings in the thigh are the muscles more commonly affected. The striking feature is a gradually increasing difficulty of extending the limb at the elbow or knee, and progressive flexion of the joint. The affected muscle is larger and firmer than normal, and its electric excitability is diminished. In tertiary syphilis, individual muscles may become the seat of interstitial myositis or of gummata, and these affections readily yield to anti-syphilitic remedies.

_Tuberculous disease_ in muscle, while usually due to extension from adjacent tissues, is sometimes the result of a primary infection through the blood-stream. Tuberculous nodules are found disseminated throughout the muscle; the surrounding tissues are indurated, and central caseation may take place and lead to abscess formation and sinuses. We have observed this form of tuberculous disease in the gastrocnemius and in the psoas--in the latter muscle apart from tuberculous disease in the vertebrae.

1. Tendinitis.#--German authors describe an inflammation of tendon as

distinguished from inflammation of its sheath, and give it the name tendinitis. It is met with most frequently in the tendo-calcaneus in gouty and rheumatic subjects who have overstrained the tendon, especially during cold and damp weather. There is localised pain which is aggravated by walking, and the tendon is sensitive and swollen from a little above its insertion to its junction with the muscle. Gouty nodules may form in its substance. Constitutional measures, massage, and douching should be employed, and the tendon should be protected from strain.

1. Calcification and Ossification in Muscles, Tendons, and

Fasciae.#--_Myositis ossificans._--Ossifications in muscles, tendons, fasciae, and ligaments, in those who are the subjects of arthritis deformans, are seldom recognised clinically, but are frequently met with in dissecting-rooms and museums. Similar localised ossifications are met with in Charcot's disease of joints, and in fractures which have repaired with exuberant callus. The new bone may be in the form of spicules, plates, or irregular masses, which, when connected with a bone, are called _false exostoses_ (Fig. 110).

[Illustration: FIG. 110.--Ossification in Tendon of Ilio-psoas Muscle.]

_Traumatic Ossification in Relation to Muscle._--Various forms of ossification are met with in muscle as the result of a single or of repeated injury. Ossification in the crureus or vastus lateralis muscle has been frequently observed as a result of a kick from a horse. Within a week or two a swelling appears at the site of injury, and becomes progressively harder until its consistence is that of bone. If the mass of new bone moves with the affected muscle, it causes little inconvenience. If, as is commonly the case, it is fixed to the femur, the action of the muscle is impaired, and the patient complains of pain and difficulty in flexing the knee. A skiagram shows the extent of the mass and its relationship to the femur. The treatment consists in excising the bony mass.

Difficulty may arise in differentiating such a mass of bone from sarcoma; the ossification in muscle is uniformly hard, while the sarcoma varies in consistence at different parts, and the X-ray picture shows a clear outline of the bone in the vicinity of the ossification in muscle, whereas in sarcoma the involvement of the bone is shown by indentations and irregularity in its contour.

A similar ossification has been observed in relation to the insertion of the brachialis muscle as a sequel of dislocation of the elbow. After reduction of the dislocation, the range of movement gradually diminishes and a hard swelling appears in front of the lower end of the humerus. The lump continues to increase in size and in three to four weeks the disability becomes complete. A radiogram shows a shadow in the muscle, attached at one part as a rule to the coronoid process. During the next three or four months, the lump in front of the elbow remains stationary in size; a gradual decrease then ensues, but the swelling persists, as a rule, for several years.

[Illustration: FIG. 111.--Calcification and Ossification in Biceps and Triceps.

(From a radiogram lent by Dr. C. A. Adair Dighton.)]

Ossification in the adductor longus was first described by Billroth under the name of "rider's bone." It follows bruising and partial rupture of the muscle, and has been observed chiefly in cavalry soldiers. If it causes inconvenience the bone may be removed by operation.

Ossification in the deltoid and pectoral muscles has been observed in foot-soldiers in the German army, and has received the name of "drill-bone"; it is due to bruising of the muscle by the recoil of the rifle.

_Progressive Ossifying Myositis._--This is a rare and interesting disease, in which the muscles, tendons, and fasciae throughout the body become the seat of ossification. It affects almost exclusively the male sex, and usually begins in childhood or youth, sometimes after an injury, sometimes without apparent cause. The muscles of the back, especially the trapezius and latissimus, are the first to be affected, and the initial complaint is limitation of movement.

[Illustration: FIG. 112.--Ossification in Muscles of Trunk in a case of generalised Ossifying Myositis.

(Photograph lent by Dr. Rustomjee.)]

The affected muscles show swellings which are rounded or oval, firm and elastic, sharply defined, without tenderness and without discoloration of the overlying skin. Skiagrams show that a considerable deposit of lime salts may precede the formation of bone, as is seen in Fig. 111. In course of time the vertebral column becomes rigid, the head is bent forward, the hips are flexed, and abduction and other movements of the arms are limited. The disease progresses by fits and starts, until all the striped muscles of the body are replaced by bone, and all movements, even those of the jaws, are abolished. The subjects of this disease usually succumb to pulmonary tuberculosis.

There is no means of arresting the disease, and surgical treatment is restricted to the removal or division of any mass of bone that interferes with an important movement.

A remarkable feature of this disease is the frequent presence of a deformity of the great toe, which usually takes the form of hallux valgus, the great toe coming to lie beneath the second one; the shortening is usually ascribed to absence of the first phalanx, but it has been shown to depend also on a synostosis and imperfect development of the phalanges. A similar deformity of the thumb is sometimes met with.

Microscopical examination of the muscles shows that, prior to the deposition of lime salts and the formation of bone, there occurs a proliferation of the intra-muscular connective tissue and a gradual replacement and absorption of the muscle fibres. The bone is spongy in character, and its development takes place along similar lines to those observed in ossification from the periosteum.

1. Tumours of Muscle.#--With the exception of congenital varieties, such

as the rhabdomyoma, tumours of muscle grow from the connective-tissue framework and not from the muscle fibres. Innocent tumours, such as the fibroma, lipoma, angioma, and neuro-fibroma, are rare. Malignant tumours may be primary in the muscle, or may result from extension from adjacent growths--for example, implication of the pectoral muscle in cancer of the breast--or they may be derived from tumours situated elsewhere. The diagnosis of an intra-muscular tumour is made by observing that the swelling is situated beneath the deep fascia, that it becomes firm and fixed when the muscle contracts, and that, when the muscle is relaxed, it becomes softer, and can be moved in the transverse axis of the muscle, but not in its long axis.

Clinical interest attaches to that form of slowly growing fibro-sarcoma--_the recurrent fibroid of Paget_--which is most frequently met with in the muscles of the abdominal wall. A rarer variety is the ossifying chondro-sarcoma, which undergoes ossification to such an extent as to be visible in skiagrams.

In primary sarcoma the treatment consists in removing the muscle. In the limbs, the function of the muscle that is removed may be retained by transplanting an adjacent muscle in its place.

_Hydatid cysts_ of muscle resemble those developing in other tissues.

DISEASES OF TENDON SHEATHS

Tendon sheaths have the same structure and function as the synovial membranes of joints, and are liable to the same diseases. Apart from the tendon sheaths displayed in anatomical dissections, there is a loose peritendinous and perimuscular cellular tissue which is subject to the same pathological conditions as the tendon sheaths proper.

1. Teno-synovitis.#--The toxic or infective agent is conveyed to the

tendon sheaths through the blood-stream, as in the gouty, gonorrhoeal, and tuberculous varieties, or is introduced directly through a wound, as in the common pyogenic form of teno-synovitis.

_Teno-synovitis Crepitans._--In the simple or traumatic form of teno-synovitis, although the most prominent etiological factor is a strain or over-use of the tendon, there would appear to be some other, probably a toxic, factor in its production, otherwise the affection would be much more common than it is: only a small proportion of those who strain or over-use their tendons become the subjects of teno-synovitis. The opposed surfaces of the tendon and its sheath are covered with fibrinous lymph, so that there is friction when they move on one another.

The _clinical features_ are pain on movement, tenderness on pressure over the affected tendon, and a sensation of crepitation or friction when the tendon is moved in its sheath. The crepitation may be soft like the friction of snow, or may resemble the creaking of new leather--"saddle-back creaking." There may be swelling in the long axis of the tendon, and redness and oedema of the skin. If there is an effusion of fluid into the sheath, the swelling is more marked and crepitation is absent. There is little tendency to the formation of adhesions.

In the upper extremity, the sheath of the long tendon of the biceps may be affected, but the condition is most common in the tendons about the wrist, particularly in the extensors of the thumb, and it is most frequently met with in those who follow occupations which involve prolonged use or excessive straining of these tendons--for example, washerwomen or riveters. It also occurs as a result of excessive piano-playing, fencing, or rowing.

At the ankle it affects the peronei, the extensor digitorum longus, or the tibialis anterior. It is most often met with in relation to the tendo-calcaneus--_Achillo-dynia_--and results from the pressure of ill-fitting boots or from the excessive use and strain of the tendon in cycling, walking, or dancing. There is pain in raising the heel from the ground, and creaking can be felt on palpation.

The _treatment_ consists in putting the affected tendon at rest, and with this object a splint may be helpful; the usual remedies for inflammation are indicated: Bier's hyperaemia, lead and opium fomentations, and ichthyol and glycerine. The affection readily subsides under treatment, but is liable to relapse on a repetition of the exciting cause.

_Gouty Teno-synovitis._--A deposit of urate of soda beneath the endothelial covering of tendons or of that lining their sheaths is commonly met with in gouty subjects. The accumulation of urates may result in the formation of visible nodular swellings, varying in size from a pea to a cherry, attached to the tendon and moving with it. They may be merely unsightly, or they may interfere with the use of the tendon. Recurrent attacks of inflammation are prone to occur. We have removed such gouty masses with satisfactory results.

_Suppurative Teno-synovitis._--This form usually follows upon infected wounds of the fingers--especially of the thumb or little finger--and is a frequent sequel to whitlow; it may also follow amputation of a finger. Once the infection has gained access to the sheath, it tends to spread, and may reach the palm or even the forearm, being then associated with cellulitis. In moderately acute cases the tendon and its sheath become covered with granulations, which subsequently lead to the formation of adhesions; while in more acute cases the tendon sloughs. The pus may burst into the cellular tissue outside the sheath, and the suppuration is liable to spread to neighbouring sheaths or to adjacent bones or joints--for example, those of the wrist.

The _treatment_ consists in inducing hyperaemia and making small incisions for the escape of pus. The site of incision is determined by the point of greatest tenderness on pressure. After the inflammation has subsided, active and passive movements are employed to prevent the formation of adhesions between the tendon and its sheath. If the tendon sloughs, the dead portion should be cut away, as its separation is extremely slow and is attended with prolonged suppuration.

_Gonorrhoeal Teno-synovitis._--This is met with especially in the tendon sheaths about the wrist and ankle. It may occur in a mild form, with pain, impairment of movement, and oedema, and sometimes an elongated, fluctuating swelling, the result of serous effusion into the sheath. This condition may alternate with a gonorrhoeal affection of one of the larger joints. It may subside under rest and soothing applications, but is liable to relapse. In the more severe variety the skin is red, and the swelling partakes of the characters of a phlegmon with threatening suppuration; it may result in crippling from adhesions. Even if pus forms in the sheath, the tendon rarely sloughs. The treatment consists in inducing hyperaemia by Bier's method; and a vaccine may be employed with satisfactory results.

1. Tuberculous Disease of Tendon Sheaths.#--This is a comparatively common

affection, and is analogous to tuberculous disease of the synovial membrane of joints. It may originate in the sheath, or may spread to it from an adjacent bone.

The commonest form--hydrops--is that in which the synovial sheath is distended with a viscous fluid, and the fibrinous material on the free surface becomes detached and is moulded into melon-seed bodies by the movement of the tendon. The sheath itself is thickened by the growth of tuberculous granulation tissue. The bodies are smooth and of a dull-white colour, and vary greatly in size and shape. There may be an overgrowth of the fatty fringes of the synovial sheath, a condition described as "arborescent lipoma."

The _clinical features_ vary with the tendon sheath affected. In the common flexor sheath of the hand an hour-glass-shaped swelling is formed, bulging above and below the transverse carpal (anterior annular) ligament--formerly known as _compound palmar ganglion_. There is little or no pain, but the fingers tend to be stiff and weak, and to become flexed. On palpation, it is usually possible to displace the contents of the sheath from one compartment to the other, and this may yield fluctuation, and, what is more characteristic, a peculiar soft crepitant sensation from the movement of the melon-seed bodies. In the sheath of the peronei or other tendons about the ankle, the swelling is sausage-shaped, and is constricted opposite the annular ligament.

The onset and progress of the affection are most insidious, and the condition may remain stationary for long periods. It is aggravated by use or strain of the tendons involved. In exceptional cases the skin is thinned and gives way, resulting in the formation of a sinus.

_Treatment._--In the common flexor sheath of the palm, an attempt may be made to cure the condition by removing the contents through a small incision and filling the cavity with iodoform glycerine, followed by the use of Bier's bandage. If this fails, the distended sheath is laid open, the contents removed, the wall scraped, and the wound closed.

A less common form of tuberculous disease is that in which the sheath becomes the seat of _a diffuse tuberculous thickening_, not unlike the white swelling met with in joints, and with a similar tendency to caseation. A painless swelling of an elastic character forms in relation to the tendon sheath. It is hour-glass-shaped in the common flexor sheath of the palm, elongated or sausage-shaped in the extensors of the wrist and in the tendons at the ankle. The tuberculous granulation tissue is liable to break down and lead to the formation of a cold abscess and sinuses, and in our experience is often associated with disease in an adjacent bone or joint. In the peronei tendons, for example, it may result from disease of the fibula or of the ankle-joint.

When conservative measures fail, excision of the affected sheath should be performed; the whole of the diseased area being exposed by free incision of the overlying soft parts, the sheath is carefully isolated from the surrounding tissues and is cut across above and below. Any tuberculous tissue on the tendon itself is removed with a sharp spoon. Associated bone or joint lesions are dealt with at the same time. In the after-treatment the functions of the tendons must be preserved by voluntary and passive movements.

1. Syphilitic Affections of Tendon Sheaths.#--These closely resemble the

syphilitic affections of the synovial membrane of joints. During the secondary period the lesion usually consists in effusion into the sheath; gummata are met with during the tertiary period.

Arborescent lipoma has been found in the sheaths of tendons about the wrist and ankle, sometimes in a multiple and symmetrical form, unattended by symptoms and disappearing under anti-syphilitic treatment.

1. Tumours of Tendon Sheaths.#--Innocent tumours, such as _lipoma_,

_fibroma_, and _myxoma_, are rare. Special mention should be made of the _myeloma_ which is met with at the wrist or ankle as an elongated swelling of slow development, or over the phalanx of a finger as a small rounded swelling. The tumour tissue, when exposed by dissection, is of a chocolate or chamois-yellow colour, and consists almost entirely of giant cells. The treatment consists in dissecting the tumour tissue off the tendons, and this is usually successful in bringing about a permanent cure.

All varieties of _sarcoma_ are met with, but their origin from tendon sheaths is not associated with special features.