When the paralysis is bilateral, the symmetrical appearance of the face renders the condition liable to be overlooked.

Treatment.—In addition to removing the cause, when this is possible, recovery of function may be promoted by the administration of drugs, such as potassium iodide, strychnin, or iron, by the application of blisters, or by massage and electricity. These measures are most useful in cases due to blows or exposure to cold. When the nerve is accidentally divided in the course of an operation on the face, it should immediately be sutured. So long as the electrical reactions of the affected muscles indicate an incomplete lesion, recovery may be confidently expected (Sherren). When the reaction of degeneration is present and the paralysis has lasted for more than six months, there is little hope of recovery, and recourse should be had to operation, to restore the function of the nerve by grafting its distal end on to the trunk of the hypoglossal nerve. To prevent paralysis of the tongue the lingual nerve may be divided, and its proximal end anastomosed with the distal end of the hypoglossal.

The facial may be grafted on the accessory nerve, but the associated movements of the face which then accompany movements of the shoulder often prove inconvenient.

Facial Spasm.—Clonic contraction of the facial muscles (histrionic spasm) occasionally results from irritative lesions in the cortex or pons. Sometimes all the muscles are involved, sometimes only one, for example the orbicularis oculi (palpebrarum)—blepharospasm. This condition may be induced reflexly from irrigation of the trigeminal nerve, notably of branches that supply the nasal cavities and the teeth.

The treatment consists in removing any source of peripheral irritation that may be present, in employing massage, and in administering nerve tonics, bromides, and other drugs. In severe cases, the facial nerve may be stretched with benefit, either at its exit from the stylo-mastoid foramen or on the face.

VIII. Acoustic or Auditory Nerve.—The acoustic nerve is liable to be damaged along with the facial in tumours of the cerebello-pontine angle, and in fractures which traverse the internal auditory meatus. Both nerves also may be torn across just before they enter the meatus in severe brain injuries apart from fracture. Complete and permanent deafness results. Effusion of blood into the nerve sheath, or into the internal or middle ear, causes transitory deafness, and the patient suffers from noises in the ear, giddiness, and interference with equilibration.

IX. The Glosso-pharyngeal Nerve is comparatively seldom injured. When it is compressed by a tumour in the region of the medulla, there is interference with speech and deglutition, ulcers form on the tongue, and oedema of the glottis may supervene.

X. The Vagus or Pneumogastric Nerve is seldom injured within the cranial cavity.

In the neck, it is liable to be divided or ligated in the course of operations for the removal of malignant or tuberculous glands, for goitre, or for ligation of the common carotid. Division of the nerve on one side, or even removal of a portion of it, is not as a rule followed by any change in the pulse or respiration. If it is irritated, however, for example by being grasped with an artery forceps, there is inhibition of the heart, and if it is accidentally ligated, there may be persistent vomiting.

Division of the main trunk, or of its recurrent branch on one side, results in paralysis of the corresponding posterior crico-arytaenoid muscle—the muscle that opens the glottis. This condition is known as unilateral abductor paralysis, and is accompanied by interference with inspiration and phonation. If both nerves are divided, bilateral abductor paralysis results: the vocal cords flap together, producing a crowing sound on inspiration and embarrassment of breathing, and tracheotomy may be necessary to prevent asphyxia.

The vagus and recurrent nerves have been successfully sutured after having been divided accidentally.

XI. Accessory or Spinal Accessory Nerve.—This nerve is seldom damaged within the skull. It supplies the sterno-mastoid and trapezius; but as these muscles usually have an additional nerve supply from the cervical plexus, the accessory may be divided, or a considerable portion of it resected, as, for example, in the treatment of spasmodic torticollis, without any serious disablement resulting. It is liable to be accidentally divided in excising malignant or tuberculous glands in the neck. When, however, the accessory is the only source of supply to these muscles, its division is followed by considerable disablement, which appears to depend almost entirely on the paralysis of the trapezius. The head is inclined slightly forward, the shoulder is depressed, the arm hangs heavily by the side and is slightly rotated forward, the scapula is drawn away from the spine and rotated on its horizontal axis, and there is slight cervical scoliosis with the concavity towards the affected side. The trapezius is markedly wasted, and is, therefore, less prominent in the neck than normally, and the functions of the arm and shoulder are impaired, especially in making overhead movements. In time other muscles compensate in part for the loss of the trapezius.

When divided accidentally, the nerve should be immediately sutured. Even when the paralysis has lasted for some time, secondary suture should be attempted; if this is impossible, the peripheral end should be anastomosed with the anterior primary divisions of the third and fourth cervical nerves (Tubby). Massage, electricity, and the administration of tonics are also indicated.

XII. Hypoglossal Nerve.—This nerve has been ruptured in fractures passing through the canalis hypoglossi (anterior condylar foramen). It is also liable to be divided in wounds of the submaxillary region—for example, in cut throat, or during the operation for ligation of the lingual artery, or the removal of diseased lymph glands.

The paralysed half of the tongue undergoes atrophy. When the tongue is protruded, it deviates towards the paralysed side, being pushed over by the active muscles of the opposite side. Speech and mastication are interfered with, the tongue feeling too large for the mouth; in time this disability is to a large extent overcome.

The Cervical Sympathetic.—The cervical sympathetic cord and its ganglia may be injured in the neck by stabs or gun-shot wounds, or in the course of deep dissections in the neck; and in injuries of the lower part of the cervical enlargement of the spinal cord (p. 417) or of the first dorsal nerve root.

Paralysis of the cervical sympathetic is characterised by diminution in the size of the pupil on the affected side. The pupil does not dilate when shaded, nor when the skin of the neck is pinched—"loss of the cilio-spinal reflex." The palpebral fissure is smaller than its fellow, and the eyeball sinks into the orbit. There is anidrosis or loss of sweating on the side of the face, neck, and upper part of the thorax, and on the whole upper extremity of the affected side.



CHAPTER XV

DISEASES OF THE CRANIAL BONES

Suppurative periostitis and osteomyelitis—Tuberculosis— Syphilis—Tumours.

Suppurative Periostitis and Osteomyelitis.—These conditions may be the result of infection through the blood stream, but as a rule they follow upon a breach of the surface caused by a wound, a severe burn as in epileptics, a tertiary syphilitic ulcer, or a compound fracture that has become infected. Sometimes they follow suppuration in the middle ear and mastoid or in the frontal sinus, and epithelioma and rodent cancer that has ulcerated and become infected after spreading from the face towards the vertex. They are occasionally associated with acute cellulitis of the scalp. When the infection is blood-borne suppuration occurs on both aspects of the bone—a point of importance in treatment.

The illness is usually ushered in by a rigor, and this is soon followed by other signs of suppuration—high temperature, pain and tenderness, and the formation of a fluctuating swelling in relation to the bone. When pus forms between the bone and the dura, there is a characteristic oedema of the overlying area of the scalp—spoken of as Pott's puffy tumour—which is of value as indicating the extent of the disease in the bone, and of the collection of pus between it and the dura. When suppuration occurs under the pericranium, an incision gives exit to a quantity of pus, and exposes an area of bare bone. If the incision is made early, this bone may soon be covered by granulations and recover its vitality; but if operation is delayed, it usually undergoes necrosis. The sequestrum that forms includes, as a rule, only the outer table, but in some cases the whole thickness of the bone undergoes necrosis. In either case the separation of the sequestrum is an exceedingly slow process, and is not accompanied by the formation of new bone. When the whole thickness of the skull is lost, there may be a protrusion of the contents of the skull—hernia cerebri; should the patient survive, the gap becomes filled in by a dense fibrous membrane which is fused with the dura mater.

Serious complications, in the form of meningitis, cerebral abscess, sinus phlebitis, and general pyaemia, are liable to develop at any time during the progress of the infection, and we have seen pyaemia develop after the suppuration in the skull had been recovered from.

Treatment.—Early, free, and, if necessary, multiple incisions are indicated to admit of disinfection of the affected area, and of the establishment of drainage. If the symptoms point to suppuration having occurred between the bone and the dura, the skull should be trephined and further bone removed with the rongeur forceps as may be required.

Time may be saved by separating the sequestrum with the aid of an elevator or sharp spoon, or by chiselling away the dead part till healthy vascular bone is reached.

Tuberculosis of the cranial vault is usually met with in children. The disease commences in the diploe, and results in the formation of a central sequestrum, around and beneath which the tuberculous process spreads. Granulations form between the skull and the dura, and on the outer aspect lifting up the pericranium. The sequestrum is slowly thrown off, and when separated is circular like a coin and presents worm-eaten edges.

A circumscribed, tender swelling forms, at first yielding an obscure sensation of fluctuation, but later, when the pus is no longer confined under the pericranium, assuming the characters of a cold abscess, which gradually becomes superficial, and eventually bursts through the scalp, forming one or more sinuses.

The abscess should be laid open, all tuberculous granulations scraped away, and the sequestrum removed, with the aid of the chisel if it has not already become loose. On inserting the finger through the opening, it appears to penetrate to an alarming extent; this is due to the accumulation of tuberculous material between the skull and the dura mater, depressing the latter. After healing is completed, a depression or gap in the bone remains.

Syphilis.—Syphilitic affections occur during the tertiary period of the disease, and usually implicate the frontal and parietal bones (Fig. 202). They are described in Volume I., p. 462.



Tumours.—Osteoma of the skull has been described with diseases of bone (Volume I., p. 481).

Sarcoma.—All forms of sarcoma are met with, implicating the bones of the skull. They may originate in the pericranium, in the diploe, or in the dura mater, and usually involve the bones of the vault. They sometimes occur in children (Fig. 203).



The tumour grows chiefly towards the surface, but it also tends to invade the cranial cavity, and may thus assume the shape of a dumb-bell. Its growth is usually rapid, and results in the formation of a diffuse soft swelling, which sometimes pulsates, and sooner or later fungates through the skin. On account of its rapid growth the tumour is liable to be mistaken for an abscess, and in some cases the nature of the disease is only discovered after making an exploratory incision, and finding that the finger passes through a softened area in the bone.

When the cranial cavity is encroached upon, signs of compression ensue. After the tumour has fungated, infective complications within the skull are liable to develop. In all cases the prognosis is extremely unfavourable.

If diagnosed sufficiently early, an attempt may be made to remove the tumour, but often the operation has to be abandoned, either on account of the haemorrhage which attends it, or because of the extent of the disease.

The bones of the skull may become the seat of secondary growths by the direct spread of cancer from the soft parts, e.g. rodent cancer (Fig. 204), or by metastasis of cancer or sarcoma from distant parts of the body, or of thyreoid tumours. Metastatic cancer would appear to be conveyed by the blood stream; it may occur in a diffuse form—cancerous osteomalacia—softening the calvaria so that at the post-mortem examination it may be removed with the knife instead of the saw; or it occurs in a discrete or scattered form, and then the macerated skull presents a number of circular and oval perforations.



CHAPTER XVI

THE VERTEBRAL COLUMN AND SPINAL CORD

Surgical Anatomy—Injuries of the spinal cord: Concussion; Traumatic haematorrachis; Traumatic haematomyelia; Total transverse lesions at different levels; Partial lesions; "Railway spine"—Injuries of the vertebral column: Sprain; Isolated dislocation of articular processes; Isolated fracture of arches and spinous processes; Compression fracture of bodies—Traumatic spondylitis—Fracture-dislocation—Penetrating wounds.

Surgical Anatomy.—The veretebral column is the central axis of the skeleton, and affords a protecting casement for the spinal cord.

The spine is movable in all directions—flexion, extension, lateral flexion, and rotation around the long axis of the column. Flexion is accompanied by compression of the intervertebral discs, and by a slight forward movement of each vertebra on the one below it. This forward movement is checked by the tension of the ligamenta flava which stretch between the laminae.

In the infant, the spine is either straight or presents one long antero-posterior curve with its convexity backwards. With the assumption of the erect posture the normal S-shaped curve is developed, the cervical and lumbar segments arching forward, while the thoracic and sacral segments arch backward.

Through the skin it is often difficult to identify with certainty the individual spinous processes. The spine of the seventh cervical vertebra,—vertebra prominens—and that of the first thoracic, are those most readily felt. While the arm hangs by the side, the root of the spine of the scapula is opposite the third thoracic spine, and the lower angle of the scapula is on the same level as the seventh. The twelfth thoracic vertebra may be recognised by tracing back to it the last rib. A line joining the highest points of the iliac crests crosses the fourth lumbar spine; and the second sacral spine is on the same level as the posterior superior iliac spine. The bodies of the upper cervical vertebrae may be felt through the posterior wall of the pharynx. The cricoid cartilage corresponds in level to that of the lower border of the sixth cervical vertebrae and its transverse process.

It is important for surgical purposes to bear in mind that most of the spinous processes do not lie on the same level as their corresponding bodies. The tips of the spines of the cervical and first two or three thoracic vertebrae lie, roughly speaking, opposite the lower edge of their respective bodies; those of the remaining thoracic vertebrae lie opposite the body of the vertebrae below; while the spines of the lumbar vertebrae lie opposite the middle of their corresponding bodies.

The vertebral canal contains the spinal cord so suspended within its membranes that it does not touch the bones, and is not disturbed by the movements of the vertebral column.

The membranes of the cord are continuous with those of the brain. The arachno-pia invests the cord and furnishes a sheath to each of the spinal nerves as it passes out through the intervertebral foramen. The arachno-pial space is filled with cerebro-spinal fluid, which forms a water-bed for the cord, continuous with that at the base of the brain. The dura mater constitutes the enveloping sheath of the cord. It hangs from the edge of the foramen magnum as a tubular sac, and is connected to the bones only opposite the intervertebral foramina, where it is prolonged on to each spinal nerve as part of its sheath. Between the dura and the bony wall of the canal is a space filled with loose areolar tissue and traversed by large venous sinuses. The dura extends as far as the upper edge of the sacrum.

The spinal cord extends from the foramen magnum to the level of the disc between the first and second lumbar vertebrae. The cervical enlargement, which includes the lower four cervical and the upper two thoracic segments, ends opposite the seventh cervical spine. The lumbar enlargement lies opposite the last three thoracic spines.

One pair of spinal nerves leaves each "segment" of the cord. On leaving the cord the nerves incline slightly downwards towards the foramina by which they make their exit from the canal. The obliquity of the nerves gradually increases, till in the lower part of the canal—from the second lumbar vertebra onward—they run parallel with the filum terminale and together constitute the cauda equina.

It is to be borne in mind that owing to the fact that the cord is relatively shorter than the canal, the tips of the spinous processes lie a considerable distance lower than the segments of the cord with which they correspond numerically. To estimate the level of the segment of the cord which is injured: in the cervical region add one to the number of the vertebra counted by the spines; in the upper thoracic region add two, in the lower thoracic region add three, and this will give the corresponding segment. The lower part of the eleventh thoracic spinous process and the space below it are opposite the lower three lumbar segments. The twelfth thoracic spinous process and the space below it are opposite the sacral segments (Chipault).

Functions.—The essential function of the spinal cord is to transmit motor and sensory impulses between the brain and the rest of the body. The general course of the fibres by which these impulses travel has already been described (p. 331).

In the grey matter there are groups of nerve-cells—"centres"—which govern certain reflex movements. The most important of these—the centres for the rectal, the vesical, and the patellar reflexes—are situated in the lumbar enlargement.

In the great majority of cases of spinal disease or injury coming under the notice of the surgeon the symptoms are bilateral, that is, are of the nature of paraplegia, and the whole of the body below the level of the segment affected is involved in the paralysis. Lesions affecting only one-half of the cord are rare and give rise to symptoms which are exceedingly complicated. When the lesion implicates the nerve-roots only, the symptoms are confined to the area supplied by the affected nerves.

INJURIES OF THE SPINAL MEDULLA OR CORD

As the clinical importance of a spinal injury depends almost entirely on the degree of damage done to the cord, we shall consider injuries of the cord before those of the vertebral column. They will be described under the headings: Concussion of the Cord; Traumatic Spinal Haemorrhage; Total Transverse Lesions; Partial Lesions of the Cord and Nerve Roots; and "Railway Spine."

Concussion of the Spinal Cord.—Concussion of the cord is now regarded as a definite entity closely resembling concussion of the brain. In some cases, the underlying lesion is of a temporary character, usually in the form of a vascular disturbance such as oedema or vascular engorgement, and possibly an arterial anaemia; in other cases there is definite evidence of injury, of the nature of contusion, minute haemorrhages and blood-staining of the cerebro-spinal fluid. It must be clearly stated, that concussion of the cord may be attended with an immediate arrest of all its functions closely resembling the condition following upon complete crushing of the cord—total transverse lesion,—and it may be impossible to differentiate between the two conditions until two or more days have elapsed after the accident; it is usual, however, in concussion, as contrasted with crushing of the cord, that although motor conduction may be completely abolished, sensation is only impaired and evidence of sensory conduction can usually be elicited. If the lesion is merely a concussion, the functions of the cord will be restored within a day or two, first to full sensation and then to full motor power.

A classical instance is that of a late Governor-General of India, who on being thrown in the hunting-field was found to be paralysed in all four extremities; Paget diagnosed a total transverse lesion of the cervical cord with the necessary inference that it would inevitably have a fatal termination. The fact that the patient recovered completely, and was later able to fill two Viceroyalties, proved that the lesion must have been of the nature of a concussion of the cord.

The treatment consists in adopting the same measures as in crushing of the cord, while careful watch is observed for the signs of recovery of conduction. The usual order of recovery is first the reflexes, then sensation, and lastly, the motor functions.

Traumatic Spinal Haemorrhage.—Haemorrhage into the vertebral canal is a common accompaniment of all forms of injury to the spine, but the lower cervical region is the common seat of the severe type of haemorrhage resulting from acute flexion of the spine such as occurs especially in a fall on the head from a horse or a vehicle in motion. The blood may be effused around the cord—between it and the dura—(extra-medullary), or into its substance (intra-medullary).

Extra-medullary Haemorrhage—Haematorrachis.—The symptoms associated with extra-medullary haemorrhage are at first of an irritative kind—muscular cramps and jerkings, radiating pains along the course of the nerves pressed upon, and hyperaesthesia. It is only when the blood accumulates in sufficient quantity to exert definite pressure on the cord that symptoms of paralysis ensue, and it is characteristic of extra-medullary haemorrhage that the paralysis comes on gradually. When the effusion is in the cervical region—the commonest situation—the arms are more affected than the legs. The paralysis of the arms is of the lower neurone type, and the muscles are flaccid and undergo atrophy; the legs may exhibit a more complete degree of paralysis of the upper neurone type, with exaggeration of the knee-jerks. Blood may trickle down the canal and collect at a level lower than that of the lesion which causes the bleeding, and produce paralysis which slowly spreads from below upwards—gravitation paraplegia (Thorburn). There is blood in the cerebro-spinal fluid.

The treatment is on the same lines as in total transverse lesions. When there is evidence of progressive pressure on the cord, the blood is removed by spinal puncture if possible, or by laminectomy performed at the level suggested by the symptoms; operation is, however, rarely called for.

Intra-medullary Haemorrhage—Haematomyelia.—Traumatic haemorrhage into the substance of the cord occurs almost invariably in the lower cervical region, and results from forcible stretching of the cord by acute flexion of the neck. The blood is usually effused into the anterior cornua of the grey matter and into the central canal, and there is a varying degree of laceration of the nerve tissue, in addition to pressure exerted by the extravasated blood.

The severity of the clinical features depends upon the extent of the lesion. In contrast with what results in extra-medullary haemorrhage, the symptoms are paralytic from the outset.

When the haemorrhage is only sufficient to cause pressure on the cord, the paralysis is usually most marked in the lower extremities because the conducting fibres are pressed upon. This is associated with evanescent anaesthesia for temperature and pain, while tactile sensibility is preserved. There is retention of urine and faeces, and in young men, priapism. As the fibres which supply the dilator pupillae are involved, the pupils are contracted. The symptoms gradually subside as the extravasated blood is re-absorbed, sensation being restored before motion, and recovery may be comparatively rapid.

When the blood extravasated in the cord causes disintegration of its substance, there is complete paralysis with atrophy, and anaesthesia in the area supplied by the segments of the cord directly implicated. The paralysis in the parts below the lesion assumes the spastic form. As the lesion is usually in the upper part of the cord, it is the arms that are most frequently affected. In less severe degrees of damage the paralysis of the most distant parts, e.g. the feet, may be transitory. Even in cases in which the loss of function below the level of the lesion has been complete, recovery may take place, but it is apt to be marred by a spastic condition of the muscles concerned, due to sclerotic changes in the cord.

Except that operative treatment is contra-indicated, the treatment is the same as for extra-medullary haemorrhage, and at a later period measures may be employed to relieve the spastic condition of the muscles.

Total Transverse Lesions.—Total transverse lesions, that is, those in which the cord is completely crushed or torn across, are much more common than partial lesions, being an almost invariable accompaniment of a complete dislocation or of a fracture-dislocation of the spine. Even when the displacement of the vertebrae is only partial and temporary, the cord may be completely torn across. Similar lesions may result from stabs or bullet-wounds.

From the records of cases in which the vertebrae were injured by modern rifle bullets, even although the bony walls of the spinal canal had not been fractured and no haemorrhage had occurred within the spinal canal, the cord in the vicinity was degenerated into a "custard-like material" incapable of any conducting power (Makins). According to Stevenson, "this must have been due to the vibratory concussion communicated to it by the passage of the bullet at a high rate of velocity." The importance of this observation lies in the fact that in such cases no benefit can follow operative interference.

The clinical features vary with the level at which the cord is injured, and the diagnosis as to the nature and site of the lesion is to be made by a careful analysis of the symptoms. By gently passing the fingers under the patient's back as he lies recumbent, any irregularity in the spinous processes or laminae may be detected, but movement of the patient to admit of a more direct examination of the spine is attended with considerable risk, and should be avoided. Skiagrams are indispensable, as they show the exact site and nature of the lesion.

Immediate Symptoms.—At whatever level the cord is damaged there is immediate and complete paralysis of motion and sensation (paraplegia) below the seat of injury, and the paralysed limbs at once become flaccid. On careful examination, a narrow zone of hyperaesthesia may be mapped out above the anaesthetic area, and the patient may complain of radiating pain in the lines of the nerves derived from the segments of the cord directly implicated. In complete transverse lesions the paralytic symptoms are symmetrical; any marked difference on the two sides indicates an incomplete lesion.

Retention of urine and retention or incontinence of faeces are constant symptoms. In young men priapism is common—the corpus cavernosum penis is filled with blood without actual erection. There is other evidence of vaso-motor paralysis in the form of dilatation of the subcutaneous vessels, and local elevation of temperature in the paralysed parts. The deep reflexes, including the tendon reflexes, are permanently lost.

Unless regularly emptied by the catheter, the bladder becomes distended, and there is dribbling of urine—the overflow from the full bladder. As the bladder is unable to empty itself, and its trophic nerve supply is interfered with, the use of the catheter involves considerable risk of infection, unless the most rigid precautions are adopted. Hypostatic pneumonia is liable to develop. Great care in nursing is necessary to prevent trophic sores occurring over parts subjected to pressure, such as the sacrum, the scapulae, the heels, and the elbows.

Later symptoms are the result of descending degeneration taking place in the antero-lateral columns of the cord. There are often violent and painful jerkings of the muscles of the limbs; the muscles become rigid and the limbs flexed.

Treatment.—When the cord is completely divided, no benefit can follow operative interference, and treatment is directed towards the prevention of infective complications from cystitis and bed-sores.

Injuries of the Cord at Different Levels.—Cervical Region.—Complete lesions of the first four cervical segments—that is, above the level of the disc between the third and fourth cervical vertebrae—are always rapidly, if not instantaneously, fatal, as respiration is at once arrested by the destruction of the fibres which go to form the phrenic nerve. It is from this cause that death results in judicial hanging.

In lesions between the fifth cervical and first thoracic segments inclusive, all four limbs are paralysed. Sensation is lost below the second intercostal space. The parts above this level retain sensation, as they are supplied by the supra-clavicular nerves which are derived from the fourth cervical segment (Fig. 205). Recession of the eyeballs, narrowing of the palpebral fissures, and contraction of the pupils result from paralysis of the cervical sympathetic. Respiration is almost exclusively carried on by the diaphragm, and hiccup is often persistent. There is at first retention of urine, followed by dribbling from overflow, and sugar is sometimes found in the urine. Priapism is common. The pulse is slow (40 to 50) and full; and the temperature often rises very high—a symptom which is always of grave omen.



When the lesion is confined to the sixth cervical segment, the arms assume a characteristic attitude as a result of the contraction of the muscles supplied from the higher segments. The upper arm is abducted and rotated out, the elbow is sharply flexed, and the hand supinated and flexed (Fig. 206). Sensation is retained along the radial side of the limb.



Total lesions of the lower cervical segments are usually fatal in from two to three days to as many weeks, from embarrassment of respiration and hypostatic pneumonia.

When the lesion is confined to the first thoracic segment, the attitude of the arms is usually that of slight abduction at the shoulder and flexion at the elbow, the forearms lie semi-pronated on the chest or belly, and there is slight flexion of the fingers. There is complete anaesthesia as high as the level of the second interspace, and along the distribution of the ulnar nerve (Fig. 205); the respiration is entirely diaphragmatic; and the ocular changes depending on paralysis of the cervical sympathetic are present.

Thoracic Region.—In injuries of the thoracic region—second to eleventh thoracic segments inclusive—the anaesthesia below the level of the lesion is complete and its upper limit runs horizontally round the body, and not parallel with the intercostal nerves. Above the anaesthetic area there is a zone of hyperaesthesia, and the patient complains of a sensation as if a band were tightly tied round the body—"girdle-pain."

The motor paralysis and the anaesthesia are co-extensive. The intercostal muscles below the seat of the lesion and the abdominal muscles are paralysed. The respiratory movements are thus impeded, and, as the patient is unable to cough, mucus gathers in the air-passages and there is a tendency to broncho-pneumonia. As the patient is unable to aid defecation or to expel flatus by straining, the bowel is liable to become distended with faeces and gas, and the meteorism which results adds to the embarrassment of respiration by pressing on the diaphragm. There is retention of urine followed by dribbling from overflow. As the reflex arc is intact there may be involuntary and unconscious micturition whenever the bladder fills.

If infection of the bladder and the formation of bed-sores are prevented, the patient may live for months or even for years. At any time, however, infection of the bladder may occur and spread to the kidneys, setting up a pyelo-nephritis; or the patient may develop an ascending myelitis, and these conditions are the most common causes of death.

Lumbo-sacral Region.—All the spinal segments representing the lumbar, sacral, and coccygeal nerves lie between the level of the eleventh thoracic and first lumbar vertebrae. Injuries of the lower thoracic and upper lumbar vertebrae, therefore, may produce complete paralysis within the area of distribution of the lumbar and sacral plexuses. The anaesthesia reaches to about the level of the umbilicus. There is incontinence of urine and faeces from the first. Priapism is absent. Bed-sores and other trophic changes are common, and there is the usual risk of complications in relation to the urinary tract.

Conus Medullaris.—A lesion confined to the conus medullaris may result from a fall in the sitting position. It is attended with slight weakness of the legs, anaesthesia involving a saddle-shaped area over the buttocks and back of the thighs, the perineum, scrotum, and penis. The urethra and anal canal are insensitive, and there is paralysis of the levatores ani, the rectal and the vesical sphincters. The testes retain their sensation.

Cauda Equina.—As the cord terminates opposite the lower border of the first lumbar vertebra, injuries below this level implicate the cauda equina. The extent of the motor and sensory paralysis varies with the level of the lesion and with the particular nerves injured. Sometimes it is complete, sometimes, selective. As a rule all the muscles of the lower extremity are paralysed, except those supplied by the femoral (anterior crural), obturator, and superior gluteal nerves. The perineal and penile muscles are also implicated. There is anaesthesia of the penis, scrotum, perineum, lower half of the buttock, and the entire lower extremity, except the front and lateral aspects of the thigh, which are supplied by the lateral cutaneous nerve and the cutaneous branches of the femoral (anterior crural). There is incontinence of urine and faeces. The prognosis is more favourable than in lesions affecting the cord itself, and the only risk to life is the occurrence of infective complications.

Partial Lesions of the Cord and Nerve Roots.—Partial lesions, such as bruises, lacerations, or incomplete ruptures, are always attended with haemorrhage into the substance of the cord, and usually result from distortions or incomplete fractures and dislocations of the spine, or from bullet wounds. They are comparatively rare.

When the nerve roots alone are injured, sensory phenomena predominate. Formication, radiating pains, and neuralgia are present in the area of distribution of the nerves implicated. There is motor paresis or paralysis, which may disappear either suddenly or gradually, or may persist and be followed by atrophy of the muscles concerned. In contrast to what is observed from pressure by tumours and inflammatory products, twitchings and cramps are rare.

In partial lesions of the cord the motor phenomena predominate. Paresis extends to the whole of the motor area below the seat of the lesion, but the weakness is more marked on one side of the body. The distal parts—feet and legs—suffer more than the proximal—arms and hands, and the extensors more than the flexors. The paresis develops slowly, varies in extent and degree, and may soon improve. Vaso-motor disturbances accompany the motor symptoms. Irritative phenomena, such as twitchings or contractures, may come on later.

The deep reflexes, particularly the knee-jerks, may be absent at first, but they soon return, and are usually exaggerated; a well-marked Babinski response may appear later. Abolition of the reflexes, therefore, does not necessarily indicate complete destruction of the cord, but their return is conclusive evidence that the lesion is a partial one. It is necessary, therefore, to defer judgment until it is determined whether the abolition of the reflexes is temporary or permanent.

Sensory disturbances may be entirely absent. When present, they are incomplete, and are chiefly irritative in character. They may not reach the same level as the motor phenomena, and the different sensory functions are unequally disturbed in the areas corresponding to the several nerve roots. There is sometimes a combination of hyperaesthesia on one side and anaesthesia on the other.

Retention of urine is not always present even in those cases in which the limbs are completely paralysed, as the fibres of one side of the cord are sufficient to maintain the functions of the bladder. The patient may be aware that the bladder is full, although he is unable to empty it. Similarly, sensation in the rectum and anus may be retained although the control of the sphincters is lost. Priapism may be present, but tends to disappear.

In partial lesions, the difficulties of diagnosis are sometimes increased by the occurrence of haemorrhage into the substance of the cord, so that symptoms of generalised pressure are superadded to those of the partial lesion. In time the symptoms due to the intra-medullary haemorrhage pass off, but those due to the tearing of the cord persist.

The prognosis is generally favourable, but must be guarded, as permanent organic changes in the cord may take place, causing a spastic condition of the muscles. When recovery is taking place the first signs are the return of the knee-jerks, and a gradual change in the limbs from the flaccid to the spastic condition. Sensibility returns in the order—touch, pain, temperature, and the parts supplied by the lowest sacral segments usually become sentient first. Voluntary power returns earlier in the flexors than in the extensors, and flexion of the toes is almost invariably the earliest voluntary movement possible. Infection from bed-sores or from the urinary tract is the most common cause of death in cases that terminate fatally.

The treatment is carried out on the same lines as for total lesions. Laminectomy, however, is indicated when there is reason to believe that the pressure is due to some cause, such as a blood-clot or a displaced fragment of bone, which is capable of being removed.

In practice when a person has lost the power of the lower extremities as the result of an accident, there are three conditions requiring ultimate differentiation—a concussion of the cord alone, a total transverse lesion and a partial lesion of the cord together with concussion. It must again be emphasised that it may not be possible to differentiate between these immediately after the accident. Two or three days may elapse before it is possible to give a definite opinion.

"Railway Spine."—This term is employed to indicate a disturbance of the nervous system which may develop in persons who have been in railway accidents, but a similar group of symptoms is met with in men engaged in laborious occupations such as coal-miners, who, after an injury to the back, develop symptoms referable to the nervous system on account of which they claim compensation not infrequently in the law-courts. It is a remarkable fact that it seldom occurs in railway employees, or in passengers who sustain gross injuries, such as fractures or lacerated wounds.

Clinical Features.—The patient usually gives a history of having been forcibly thrown backwards and forwards across the carriage at the time of the accident. He is dazed for a moment and suffers from shock or, it may be, is little the worse at the time, and is able to continue his journey. On reaching his destination, however, he feels weak and nervous, and complains of pain in his back and limbs. There is rarely any sign of local injury. For a few days he may be able to attend to business, but eventually feels unfit, and has to give it up.

The symptoms that subsequently develop are for the most part subjective, and it is difficult therefore either to corroborate or to refute them; it will be observed that while some of them are referable to the cord the greater number are referable to the brain. They usually include a feeling of general weakness, nervousness, and inability to concentrate the attention on work or on business matters. The patient is sleepless, or his sleep is disturbed by terrifying dreams. His memory is defective, or rather selective, as he can usually recall the circumstances of the accident with clearness and accuracy. He becomes irritable and emotional, complains of sensations of weight or fullness in the head, of temporary giddiness, is hypersensitive to sounds, and sometimes complains of noises in the ears. There are weakness of vision and photophobia, but there are no ophthalmoscopic changes. He has pain in the back on making any movement, and there is a diffuse tenderness or hyperaesthesia along the spine. There is weakness of the limbs, sometimes attended with numbness, and he is easily fatigued by walking. There may be loss of sexual power and irritability of the bladder, but there is seldom any difficulty in passing urine. The patient tends to lose weight, and may acquire an anxious, careworn expression, and appear prematurely aged. Special attention should be directed to the condition of the deep reflexes and to the state of the muscles, as any alteration in the reflexes or atrophy of the muscles indicates that some definite organic lesion is present.

As the symptoms are so entirely subjective, it is often extremely difficult to exclude the possibility of malingering; it is essential that the patient should be examined with scrupulous accuracy at regular intervals and careful notes made for purposes of comparison, and also that the doctor should retain an impartial attitude and not develop a bias either in favour of or against the patient's claim for compensation.

So long as litigation is pending the patient derives little benefit from treatment, but after his mind is relieved by the settlement of his claim—whether favourable to him or not—his health is usually restored by the general tonic treatment employed for neurasthenia.

INJURIES OF THE VERTEBRAL COLUMN

Partial lesions include twists or sprains, isolated dislocations of articular processes, isolated fractures of the arches and spinous processes, and isolated fractures of the vertebral bodies. The most important complete lesions are total dislocations and fracture-dislocations.

In partial lesions, the continuity of the column as a whole is not broken, and the cord sustains little damage, or may entirely escape; in complete lesions, on the other hand, the column is broken and the cord is always severely, and often irreparably, damaged.

Twists and dislocations are most common in the cervical region, that is, in the part of the spine where the forward range of movement—flexion—is greatest. Fractures are most common in the lumbar region, where flexion is most restricted. Fracture-dislocations usually occur where the range of flexion is intermediate, that is, in the thoracic region.

In all lesions accompanied by displacement, the upper segment of the spine is displaced forwards.

Twists or sprains are produced by movements that suddenly put the ligamentous and muscular structures of the spine on the stretch—in other words, by lesser degrees of the same forms of violence as produce dislocation. When the interspinous and muscular attachments alone are torn, the effects are confined to the site of these structures, but when the ligamenta flava are involved, blood may be extravasated and infiltrate the space between the dura and the bone and give rise to symptoms of pressure on the cord. The nerve roots emerging in relation to the affected vertebrae may be stretched or lacerated, and as a result radiating pains may be felt in the area of their distribution.

In the cervical region, distortion usually results either from forcible extension of the neck—for example from a violent blow or fall on the forehead forcing the head backwards—or from forcible flexion of the neck. The patient complains of severe pain in the neck, and inability to move the head, which is often rigidly held in the position of wry-neck. There is marked tenderness on attempting to carry out passive movements, and on making pressure over the affected vertebrae or on the top of the head. The maximum point of tenderness indicates the vertebra most implicated. In diagnosis, fracture and dislocation are excluded by the absence of any alteration in the relative positions of the bony points, and by the fact that passive movements, although painful, are possible in all directions.

In the lumbar region sprains are usually due to over-exertion in lifting heavy weights, or to the patient having been suddenly thrown backwards and forwards in a railway collision. The attachments of the muscles of the loins are probably the parts most affected. The back is kept rigid, and there is pain on movement, particularly on rising from the stooping posture.

Treatment.—Unless carefully treated, a sprain of the spine is liable to cause prolonged disablement. The patient should be kept at rest in bed, and, when the injury is in the cervical region, extension should be applied to the head with the nape of the neck supported on a roller-pillow. Early recourse should be had to massage, but active movements are forbidden till all acute symptoms have disappeared. In patients predisposed to tuberculosis, the period of complete rest should be materially prolonged.

Isolated Dislocation of Articular Processes.—This injury, which is most frequently met with in the cervical region and is nearly always unilateral, is commonly produced by the patient falling from a vehicle which suddenly starts, and landing on the head or shoulders in such a way that the neck is forcibly flexed and twisted. The articular process of the upper vertebra passes forward, so that it comes to lie in front of the one below.

The pain and tenderness are much less marked than in a simple twist, as the ligaments are completely torn and are therefore not in a state of tension. The patient often thinks lightly of the condition at the time of the accident, and may only apply for advice some time after on account of the deformity. The head is flexed and the face turned towards the side opposite the dislocation, the attitude closely resembling that of ordinary wry-neck, only it is the opposite sterno-mastoid that is tight. The bony displacement is best recognised by palpating the transverse process of the dislocated vertebra. In the case of the upper vertebrae this is done from the pharynx, in the lower between the sterno-mastoid and the trachea. There is pain on attempting movement, and tenderness on pressure, particularly on the side that is not displaced, as the ligaments there are on the stretch. There are often radiating pains along the line of the nerves emerging between the affected vertebrae. As the bodies are not separated, damage to the cord is exceptional. The lesion can usually be recognised in a radiogram.

Treatment.—Reduction should be attempted at once, before the vertebrae become fixed in their abnormal position. Under anaesthesia gentle extension is made on the head by an assistant, and the abnormal attitude is first slightly exaggerated to relax the ligaments and to restore mobility to the locked articular processes. The head is then forcibly flexed towards the opposite side, after which it can be rotated into its normal attitude (Kocher). Haphazard movements to effect reduction are attended with risk of damaging the cord. After reduction has been effected, the treatment is the same as that of a sprain.

Isolated Fractures of the Arches, Spinous and Transverse Processes.—Fractures of the arches and spinous processes usually result from direct violence, such as a blow or a bullet wound, and are accompanied by bruising of the overlying soft parts, irregularity in the line of the spines, and by the ordinary signs of fracture. Skiagrams are useful in showing the exact nature of the lesion. These fractures are most common in the lower cervical and in the thoracic regions, where the spines are most prominent and therefore most exposed to injury.

In many cases there are no symptoms of damage to the cord or spinal nerves, but when both laminae give way the posterior part of the arch may be driven in and cause direct pressure on the cord, or blood may be effused between the bone and the dura. In such cases immediate operation is indicated. When there are no cord symptoms, the treatment consists in securing rest, with the aid of extension, if necessary, for several weeks until the bones are reunited.

The use of the X-rays has shown that one or more of the transverse processes of the lumbar vertebrae may be chipped off by direct violence. The symptoms are pain and tenderness in the region of the fracture, and marked restriction of movement, especially in the direction of flexion. This lesion may explain some of the cases of persistent pain in the back following injuries in workmen. It is important to remember, however, that in a radiogram an un-united epiphysis may simulate a fracture.

Isolated Fracture of the Bodies—"Compression Fracture."—The "compression fracture" consists in a crushing from above downwards of the bodies—and the bodies only—of one or more vertebrae. It is due to the patient falling from a height and landing on the head, buttocks, or feet in such a way that the force is transmitted along the bodies of the vertebrae while the spine is flexed.

If the patient lands on his head, the compression fracture usually involves the lower cervical or upper thoracic vertebrae. When he lands on his buttocks or feet it is usually the lumbar or the lower thoracic vertebrae that are fractured (Fig. 207).



As a rule, there are no external signs of injury over the spine. The sternum, however, is often fractured, and irregularity and discoloration may be detected on examining the front of the chest. The recognition of a fracture of the sternum should always raise the suspicion of a fracture of the spine. On examination of the back a more or less marked projection of the spinous processes of the damaged vertebrae may be recognised. In the cervical and lumbar regions this projection may merely obliterate the normal concavity. The spinous process which forms the apex of the projection belongs to the vertebra above the one that is crushed. The cord usually escapes, but the nerves emerging in relation to the damaged vertebrae may be bruised, and this gives rise to girdle-pain.

Local tenderness is elicited on pressing over the affected vertebrae. As might be expected from the nature of the accident producing this lesion, it is often associated with serious injuries to the head, limbs, or internal organs which gravely affect the prognosis.

The treatment consists in taking the pressure off the injured vertebrae in order that the reparative material may be laid down in such a way as to restore the integrity of the column. In the cervical region, extension is applied to the head, and a roller-pillow placed beneath the neck. In the lumbar region, the extension is applied through the lower limbs, and the pillow placed under the loins. The patient is confined to bed for six or eight weeks, and before he gets up a poroplastic or plaster-of-Paris jacket is applied. This is worn for a month or six weeks.

Traumatic Spondylitis.—This condition is liable to develop in patients who have sustained a severe injury to the back. It is believed to originate in a compression fracture which has not been recognised, and is probably due to the callus thrown out for the repair of the fracture being subjected to strain and pressure too early, or to a progressive softening of the injured vertebra and of the bodies of those adjacent to it. This leads to an alteration in the shape of the affected bones, which can be demonstrated by means of the X-rays. The usual history is that some considerable time after the patient has resumed work he suffers from pain in the back, and radiating pains round the body and down the legs. He becomes more and more unfit for work, and a marked projection appears in the back and may come to involve several vertebrae. While the condition is progressive, the prominent vertebrae are painful and tender. In course of time the softening process is arrested, and the affected bones become fused, so that the area of the spine involved becomes rigid and permanent deformity results. So long as the condition is progressive the patient should be kept in the recumbent and hyper-extended position over a roller-pillow and, when he gets up, the spine should be supported by a jacket.

Dislocation and Fracture-Dislocation.—It is seldom possible at the bedside to distinguish between a complete dislocation of the spine and a fracture-dislocation. Fracture-dislocation is by far the more common lesion of the two, and is the injury popularly known as a "broken back." It may occur in any part of the column, but is most frequently met with in the thoracic and thoracico-lumbar regions. It usually results from forcible flexion of the spine, as, for example, when a miner at work in the stooping posture is struck on the shoulders by a heavy fall of coal. The spine is acutely bent, and breaks at the angle of flexion and not at the point struck. The lesion consists in a complete bilateral dislocation of the articular processes, together with a fracture through one or more of the bodies. This fracture is usually oblique, running downwards and forwards. The upper fragment with the segment of the spine above it is displaced downwards and forwards, and the cord is crushed between the posterior edge of the broken body and the arch of the vertebra above it (Fig. 208). In almost every case the cord is damaged beyond repair.



Total dislocation, in which the articular processes on both sides are displaced and the contiguous intervertebral disc separated, is rare, and is met with chiefly in the lower cervical region.

Clinical Features.—The outstanding symptoms of total lesions are referable to the damage inflicted on the cord. The diagnosis should always be made by a consideration of the mechanism of the injury and the condition of the nerve functions below the lesion. On no account should the patient be moved to enable the back to be examined, as this is attended with risk of increasing the displacement and causing further damage to the cord. On passing the fingers under the back as the patient lies recumbent, it is usually found that there is some backward projection of the spinous processes, the most prominent being that of the broken vertebra. The spinous process immediately above it is depressed as the upper segment has slipped forward. Pain, tenderness, swelling and discoloration may be present over the injured vertebrae. It is usually possible to have skiagrams taken without risk of further damage to the spine. There is complete loss of motion and sensation below the seat of the lesion. The symptoms of total transverse lesions of the cord at different levels have already been described (p. 416).

Treatment.—An attempt may be made to reduce the displacement under anaesthesia, gentle traction being made in the long axis of the spine by assistants, while the surgeon attempts to mould the bones into position. No special manipulations are necessary, as the ligaments are extensively torn, and the bones are, as a rule, readily replaced. A roller-pillow is placed under the seat of fracture to allow the weight of the body above and below to exert gentle traction, and so to relieve pressure on the cord. Operative treatment is almost never of any avail, as the cord is not merely pressed upon, but is severely crushed, or even completely torn across. Even when the cord is only partially torn, operative treatment is not likely to yield better results than are obtained by reduction and extension. The usual precautions must be taken to prevent cystitis and bed-sores.

Total fracture-dislocation between the atlas and epistropheus (axis), if attended with displacement, is instantaneously fatal (Fig. 209). This is the osseous lesion that occurs in judicial hanging. Fracture of the odontoid process may occur, however, without displacement, the transverse ligament retaining the fragment in position and protecting the cord from injury. The patient complains of stiff neck and pain, and the lesion may be recognised in a radiogram. A number of cases are recorded in which death took place suddenly weeks or months after such an injury, from softening of the transverse ligament and displacement of the bones.



Penetrating Wounds.—These result from stabs or gun-shot accidents, and are practically equivalent to compound fractures of the spine; their severity depends on the extent of the damage done to the cord, and on whether or not the wound is infected. In many cases the condition is complicated by injuries of the pleural or peritoneal cavities and their contained viscera, or by injury of the trachea, oesophagus, or large vessels and nerves of the neck. When the membranes of the cord are opened, the profuse and continued escape of cerebro-spinal fluid may prove a serious complication.

Treatment.—The wound of the soft parts is treated on the usual lines. When the spinous processes and laminae are driven in upon the cord, they must be elevated at once by operation. In injuries involving the lumbo-sacral region it is sometimes advisable to perform laminectomy for the purpose of suturing divided nerve cords.

When there is evidence that the spinal cord is completely divided, operation is contra-indicated. Attempts have been made to unite the two ends of the divided cord by sutures, but there is as yet no authentic record of restoration of function following the operation.



CHAPTER XVII

DISEASES OF THE VERTEBRAL COLUMN AND SPINAL CORD

POTT'S DISEASE: Pathology; Clinical features—Pott's disease as it affects different regions of the spine—Disease of the sacro-iliac joint; Syphilitic disease of spine; Tumours of vertebrae; Hysterical spine; Acute osteomyelitis; Rheumatic spondylitis; Arthritis deformans; Coccydynia; Tumours of cord and membranes—Spinal meningitis; Spinal myelitis—Congenital deformities: Spina bifida; Congenital sacro-coccygeal tumours. Congenital sacro-coccygeal sinuses and fistulae.

TUBERCULOUS DISEASE OF THE SPINE—POTT'S DISEASE

Percival Pott, in 1779, first described a disease of the vertebral column which is characterised by erosion and destruction of the bodies of the vertebrae. It is liable to produce an angular deformity of the spine, and to be associated with abscess formation and with nervous symptoms referable to pressure on the cord. This disease is now known to be tuberculous. It may occur at any period of life, but in at least 50 per cent. of cases it attacks children below the age of ten and rarely commences after middle life.

Morbid Anatomy.—The tuberculous process may affect any portion of the spine, and as a rule is limited to one region; several vertebrae are usually simultaneously involved. The disease may begin either in the interior of the bodies of the vertebrae—tuberculous osteomyelitis—or in the deeper layer of the periosteum on the anterior surface of the bones—tuberculous periostitis.

Osteomyelitis is the form most frequently met with in children. The disease commences as a tuberculous infiltration of the marrow, which results in softening of the bodies of the affected vertebrae, particularly in their anterior parts, and, as the disease progresses, caseation and suppuration ensue, and the destructive process spreads to the adjacent intervertebral discs. In some cases a sequestrum is formed, either on the surface or in the interior of a vertebra. The pus usually works its way towards the front and sides of the bones, and burrows under the anterior longitudinal (common) ligament. Less frequently it spreads towards the vertebral canal and accumulates around the dura, causing pressure on the cord.

The compression of the diseased vertebrae by the weight of the head and trunk above the seat of the lesion, and by the traction of the muscles passing over it, produces angling of the vertebral column. The anterior portions of the bodies being more extensively destroyed, sink in, while the less damaged posterior portions and the intact articular processes prevent complete dislocation. In this way the integrity of the canal is maintained, and the cord usually escapes being pressed upon. The spinous processes of the affected vertebrae project and form a prominence in the middle line of the back. When, as is usually the case, only two or three vertebrae are implicated, this prominence takes the form of a sharp angular projection, while if a series of vertebrae are involved, the deformity is of the nature of a gentle backward curve (Fig. 210).



The periosteal form of vertebral tuberculosis is that most frequently met with in adults. The disease begins in the deeper layer of the periosteum on the anterior aspect of the vertebrae, and extends along the surface of the bones, causing widespread superficial caries. It may attack the discs at their margins, and spread inwards between the discs and the contiguous vertebrae. Owing to the comparatively wide area of the spine implicated, this form of the disease is not attended with angular deformity, but rather with a wide backward curvature which corresponds in extent to the number of vertebrae affected. The accumulation of tuberculous pus under the periosteum and anterior longitudinal ligament is the first stage in the formation of the large abscesses with which this form of spinal tuberculosis is so commonly associated.

Effects on the Spinal Cord and Nerve Roots.—In some cases the cord and nerve roots are pressed upon by an oedematous swelling of the membranes; in others, the tuberculous process attacks the dura mater and gives rise to the formation of granulation tissue on its outer aspect—tuberculous pachymeningitis. Less frequently a collection of pus forms between the bone and the dura, and presses the cord back against the laminae. The cord is rarely subjected to pressure as a result of curving of the spine alone, but occasionally, especially in the cervical region, a sequestrum becomes displaced backward and exerts pressure on it, and it sometimes happens, also in the cervical region, that the cord is nipped by sudden displacement of diseased vertebrae—a condition comparable to a fracture-dislocation of the spine.

The severity of the symptoms is aggravated by the occurrence of inflammation of the cord—myelitis—which is not due to tuberculous disease, but to interference with its blood-supply from the associated meningitis.

Repair.—When the progress of the disease is arrested, the natural cure of the condition is brought about by the bodies of the affected vertebrae becoming fused by osseous ankylosis (Fig. 211). While this reparative process is progressing, the cicatricial contraction renders the angular deformity more acute, and it may go on increasing until the bones are completely ankylosed; this reparative process can be followed in successive skiagrams. An increase in the projection in the back, therefore, is not necessarily an unfavourable symptom, although, of course, it is undesirable.



In rare cases the disease affects only the articular or the spinous processes, producing superficial caries and a localised abscess.

Clinical Features.—The clinical features of Pott's disease vary so widely in different regions of the spine, that it is necessary to consider each region separately. To avoid repetition, however, certain general features may be first described.

Pain.—In the earliest stages, the patient complains of a feeling of tiredness, which prevents him walking far or standing for any length of time. Later, there is a constant, dull, gnawing pain in the back, increased by any form of movement, particularly such as involves jarring or bending of the spine. If the patient is a child, it is noticed that he ceases to play with his companions, and inclines to sit or lie about, usually assuming some attitude which tends to take the weight off the affected segment of the spine (Figs. 214, 217). If he is going about, the pain increases as the day goes on, but may pass off during the night. It is often referred along the course of the nerves emerging between the diseased vertebrae, and takes the form of headache, neuralgic pains in the arms or side, girdle-pain, or belly-ache, according to the seat of the lesion. Tenderness may be elicited on pressing over the spinous or transverse processes of the diseased vertebrae, or on making pressure in the long axis of the spine. These tests, however, are not of great diagnostic value, and they should be omitted, as they cause unnecessary suffering. It is to be borne in mind that in some cases the disease is not attended with any pain.

Rigidity.—The pain produced by movement of the diseased portion of the spine causes reflex contraction of the muscles passing over it, and the affected segment of the column is thus rendered rigid. If the palm of the hand is placed over the painful area while the patient attempts to make movements of stooping, nodding, or turning to the side, it is found that the vertebrae implicated move en bloc instead of gliding on one another. This rigidity of the diseased portion of the column with "boarding" of the muscles of the back is one of the earliest and most valuable diagnostic signs of Pott's disease.

Deformity.—The most common and characteristic deformity is an abnormal antero-posterior curvature, with its convexity backwards. The situation, extent, and acuteness of the bend vary with the region of the spine affected, the situation of the disease in the bone, and the number of vertebrae implicated. When the disease has destroyed the bodies of one or two vertebrae, a short, sharp, angular deformity results; when it affects the surface of several bones, a long, wide curvature.

Lateral deviation is occasionally met with in the early stages of the disease as a result of unequal muscular contraction, and in the later stages from excessive destruction of one side of a vertebra, or from partial luxation between two diseased vertebrae.

Abscess Formation.—Spinal abscesses occur with greater frequency and at an earlier stage in adults than in children, because in adults the disease usually begins on the surface of the vertebrae. Pyogenic infection of such abscesses after they have burst externally constitutes one of the chief risks to life in Pott's disease.

X-Ray Appearances.—These, when considered along with the clinical signs, usually afford valuable information as to the exact seat and nature of the lesion and the number of vertebrae involved. It is recommended to compare the skiagram with that of the normal spine from the same region and from a patient of approximately similar age. The outlines of the bodies are woolly or blurred; in the early stage there may be clear areas corresponding to cheesy foci. In progressive cases the bodies may be altered in shape and in size, and from destruction and collapse of the bones there is altered spacing, both of the bodies and of the ribs. In the interpretation of skiagrams, help is often obtained from an alteration in the axis of bodies, an angular deviation often drawing attention to the lesion which is located at the "angle." In children (Fig. 213) there is often a spindle-shaped shadow, outlined against the vertebral column, which is due to a cold abscess, and which extends above and below the bodies actually involved in the tuberculous process. The fusion of the bodies by new bone, which accompanies repair, can be followed in skiagrams taken at intervals.



Cord and Nerve Symptoms.—When the spinal cord is pressed upon, the motor fibres are first affected as they lie superficially on the antero-lateral aspects of the cord, and are more sensitive to pressure. There is at first weakness or paresis of the muscles supplied from the part of the cord below the seat of pressure. The knee-jerks and plantar reflexes are exaggerated, and there is marked ankle clonus. Later, there is paralysis of the spastic type, varying in extent and sometimes amounting to complete paraplegia, and this may come on gradually or quite suddenly. There is wasting of muscles from disuse, and later a tendency to contracture and the development of deformities, as a result of sclerosis or descending degeneration of the cord.

The sensory fibres usually escape, although in some cases there is partial anaesthesia and perversion of sensation. When there is also myelitis, loss of sensibility to pain (analgesia) below the level of the lesion is one of the most characteristic symptoms. In severe cases there is incontinence of urine and of faeces, as the patient loses control of the sphincters. Acute bed-sores are not uncommon.

The symptoms referable to pressure on the nerve roots at their points of emergence are pain and hyperaesthesia along the course of the nerves that are pressed upon, and occasionally weakness and wasting of the muscles supplied by them; girdle-pain is often a prominent symptom in adults.

In the diagnosis of Pott's disease in young children, chief stress is laid on the demonstration of rigidity of the affected portion of spine; the child is laid prone and is lifted by the legs and feet so as to hyper-extend the spine; in Pott's disease the spine is held rigid, while in the rickety and other conditions that resemble it, the movements are normal.

Treatment of Pott's Disease.—In addition to the general treatment of tuberculosis, the essential factor consists in immobilising the spine in the recumbent posture and in the attitude of hyper-extension; this must be persisted in until the diseased vertebrae become fused together or ankylosed by new bone, a result which is estimated partly by the disappearance of all symptoms and more accurately by observing the formation of the new bone in successive skiagrams.

Under conservative measures it is estimated that this reparative process entails an immobilisation of the spine of from one to three years; the operative procedures introduced by Albe and Hibbs bring about a bony ankylosis of the vertebrae in as many months, and may be accepted as reducing the period of spinal immobilisation in the recumbent posture to one year at the most.

The immobilisation of the recumbent spine in the attitude of hyper-extension is most efficiently carried out by an apparatus on the lines of the Bradford frame; this is made of gas-piping covered by canvas, and is easily bent as may be required in the progress of the case towards convalescence. The frame does not interfere with such extension as may be necessary, to the head, for example, in recent cervical caries, or to the lower extremities where flexion at the hip from spasmodic contraction of the psoas muscle may be efficiently relieved by weight-extension.

Gauvain's "wheel-barrow" splint and the double Thomas' splint (Fig. 215) are efficient substitutes, but Phelps' box has been discarded because it fails to secure immobilisation of the spine.

When the stage of convalescence is arrived at, and recumbency is no longer essential, the child is allowed to sit up, stand, and go about, with the restraint, however, of some apparatus that will prevent movement of the spine, except to a limited extent. The plaster-of-Paris jacket, applied over a woollen jersey, as introduced by Sayre of New York, is probably the best; the jacket is accurately moulded to the trunk while the child is partly suspended by means of a tripod and the necessary strings under the chin, occiput, and armpits. Poroplastic felt, celluloid, papier mache, and other materials, reinforced by strips of metal, may be substituted for the plaster of Paris. Various forms of jury-masts and collars have been employed to diminish the weight of the head in children with cervical caries, but have been very properly discarded as failing to perform the function expected of them.

Correction of the Angular Projection.—In cases in which the angular projection or gibbus, as it is called by continental authors, is of recent origin, it may be corrected by the method so successfully employed by Calot of Berck-sur-Mer—a plaster jacket is accurately moulded to the trunk, and a diamond-shaped window is cut in the jacket opposite the gibbus; a series of layers of cotton-wool are then applied, one on top of the other, so as to exert firm pressure on the gibbus, a plaster or elastic webbing bandage being employed to retain them and reinforce the pressure. The padding is renewed at intervals of three weeks or a month; in successful cases the projection may ultimately be replaced by a hollow.

Treatment of Abscess.—If a spinal abscess is causing symptoms or is approaching the surface, and there appears to be a risk of mixed infection, the abscess should be asperated and injected with iodoform emulsion.

Treatment of Cord-Complications.—Extension is applied, in the first instance, to the head or to the lower limbs, or to both, while some form of pillow is inserted at the seat of the disease; if the condition is merely one of oedema, the symptoms usually yield with remarkable rapidity; if they persist, in spite of extension, for three to six weeks, recourse should be had to laminectomy; it is usual to find evidence of mechanical pressure by granulation tissue, pus, or displaced bone, the relieving of which is followed by disappearance of the nerve symptoms. Some authors are lukewarm in their advocacy of this operation, but we can cite a number of cases in which, after laminectomy, an apparently hopeless paraplegia has been entirely got rid of.

Prognosis.—As regards the survival of persons who have suffered from Pott's disease, and as having an important bearing on prognosis, it may be noted that surgical museums contain many specimens illustrating the "cured" stage of the disease, in which the bodies of the vertebrae, formerly the seat of tuberculous destruction or caries, are represented by a ridge-shaped mass of new bone, forming a solid union between the segments above and below (Fig. 211), or the remains of the original bodies may still be identifiable, although they are surrounded and fused together by new bone. The latter condition is the more liable to a recrudescence of the tuberculous infection. Further, it may be inferred from the number of "cured" cases of Pott's disease met with in everyday life, that the malady is one from which recovery may be expected.

The cervical cases are recognised by the "telescoping" of the neck, the head and thorax being unduly approximated; the dorsal cases by the well-known hump or hunch-back, in which the spinous processes of the collapsed vertebrae constitute the apex of the hump; the thorax is telescoped from above downwards, the ribs are crowded together, the lower ones, it may be, inside the iliac crests, and the sternum projected forwards. The hunch-back from Pott's disease is often a remarkably capable person, both physically and intellectually.

POTT'S DISEASE AS IT AFFECTS DIFFERENT REGIONS OF THE SPINE

Upper Cervical Region, including Atlo-axoid Disease.—When the disease affects the first and second cervical vertebrae, the atlo-axoid articulation becomes involved, and as a result of the destruction of its component bones and ligaments, the atlas tends to be dislocated forward. When this occurs suddenly, the odontoid process may impinge on the medulla and upper part of the cord and cause sudden death. When the displacement occurs gradually, the atlas and axis may be separated to a considerable extent without the cord being pressed upon, and recovery with ankylosis may ensue. When the third, fourth, and fifth vertebrae are affected, the tendency to dislocation and compression of the cord is not so great, but a portion of bone may be displaced backwards and exert pressure on the cord.

The patient complains of a fixed pain in the back of the neck, and of radiating pains along the course of the sub-occipital and other cervical nerves. The neck is held rigid, and to look to the side the patient turns his whole body round. As the disease advances the head may be bent to one side as in wry-neck, or it may be retracted and the chin protruded. To take the weight of the head off the diseased vertebrae the patient often supports the chin on the hands (Fig. 214).



An abscess may form between the vertebrae and the wall of the pharynx—retro-pharyngeal abscess—the pus accumulating between the diseased bones and the prevertebral layer of the cervical fascia. The abscess may project towards the pharynx as a soft fluctuating swelling, and may cause difficulty in swallowing and breathing, and snoring during sleep; if it bursts internally it may cause suffocation. The abscess may bulge towards one or both sides of the neck, and come to the surface behind the posterior border of the sterno-mastoid muscle (Fig. 214). In some cases it comes to the surface in the sub-occipital region.

If the cord is pressed upon by inflammatory products, there is muscular weakness, beginning in the arms and extending to the legs, and sometimes followed by complete paralysis. In the early stages there is retention of urine and constipation; later the bladder and rectum are paralysed, and there is incontinence.

Sudden death may result when dislocation of the atlo-axoid joint takes place.

Cervical caries has to be diagnosed from rheumatic torticollis, and from the effects of injuries, such as a sprain or twist of the spine. When a retro-pharyngeal abscess points behind the sterno-mastoid, it is apt to be mistaken for a cold abscess originating in tuberculous cervical glands. Retro-pharyngeal abscess due to other causes is described with diseases of the pharynx.

Treatment.—Extension is applied to the head, preferably by means of an elastic band fixed to the top of the bed, and the head of the bed is raised on blocks so that the weight of the body may furnish the necessary counter-extension. Lateral movements of the head are prevented by means of sand-bags. After the acute symptoms have subsided, the spine should be fixed by some rigid apparatus, such as a double Thomas' splint prolonged so as to support the occiput (Fig. 215).



When it is considered advisable to open a retro-pharyngeal abscess, this should be done from the side of the neck by an incision along the posterior border of the sterno-mastoid, as first recommended by John Chiene. The abscess is evacuated, and the cavity filled with iodoform emulsion, and closed without drainage. An opening made through the mouth is attended with the risks of pus being inhaled into the air-passages and of pyogenic infection.

When the patient is allowed to get up, a poroplastic collar and jacket of the Minerva type which supports the head and controls the movement of the cervical and thoracic vertebrae must be worn until the cure is complete.

Cervico-thoracic Region.—When the lower cervical and upper thoracic vertebrae are affected, in addition to the fixed pain in the diseased bones, the patient complains of pain radiating along the distribution of the superficial cervical nerves and down the arms. There is often marked angular deformity. If an abscess forms, it may come to the surface in the lower part of the posterior triangle, or may spread into the posterior mediastinum or into the axilla. Sometimes the pus burrows behind the oesophagus and trachea, and it may find its way into the pleural cavity. The cord is not often pressed upon; when it is, the cervical sympathetic is implicated.

Thoracic or Dorsal Region.—When the disease is confined to the thoracic region, stiffness of the back and boarding of the vertebral muscles are prominent features. On being asked to pick up an object from the floor, the patient reaches it by bending his knees and hips, while he keeps his back rigid. He refuses to make any movement that involves jolting of the spine, such, for example, as jumping from a chair to the ground. Children often attempt to take the weight off the diseased vertebrae by placing the palms of the hands on the edge of a chair so that the weight is borne by the arms.

Angular deformity is often well marked, and may implicate several vertebrae. In order to maintain the head erect, the spine above and below the seat of disease becomes unduly arched forward—compensatory lordosis. In advanced cases the ribs become approximated, and the lower end of the sternum is projected forward. The antero-posterior diameter of the thorax is thus increased, while its vertical diameter is diminished. These changes, together with the telescoping of the vertebral bodies, lead to the deformity characteristic of the tuberculous hunch-back (Fig 216). The alterations in the shape of the chest may lead to functional disturbances of the heart and lungs.



Dorsal Abscess.—As already mentioned, the earliest stage of abscess is well seen in skiagrams (Fig. 213), especially in children. When there is an extension of the suppurative process, the pus may pass directly backwards along the posterior branches of the intercostal vessels and nerves, and come to the surface behind the transverse processes, or it may travel forward between the pleura and the ribs, and, passing along the course of the lateral cutaneous branches of the intercostals, come to the surface opposite the middle of the rib. In the latter case, the abscess is liable to be mistaken for one associated with tuberculous disease of the rib, particularly as the rib is usually found to be bare. In rare cases the pus opens into the pleura, giving rise to empyema. When the disease is on the anterior surface of the bodies of the lower thoracic vertebrae, the pus may spread down through the pillars of the diaphragm and reach the sheath of the psoas muscle.

Treatment is on the usual lines.

Thoracico-lumbar Region.—The symptoms are similar to those of disease in the thoracic region. Children while standing often assume a characteristic attitude—the hips and knees are slightly flexed, and the hands grasp the thighs just above the knees (Fig. 217). In this way the weight is partly taken off the affected vertebrae and borne by the arms. If the child is laid on its back and lifted by the heels, the spine remains rigid. By this test a projection due to tuberculous disease may be differentiated from one due to rickets, as in the latter case the projection disappears.



The patient often complains of pain in the abdomen—which in children may be mistaken for a simple "belly-ache"—and of pain shooting down the buttocks and into the legs. If the cord is pressed upon at the level of the lumbar enlargement the anal and vesical sphincters are paralysed, and the reflexes are exaggerated.

Psoas Abscess.—When an abscess forms, it usually occupies the sheath of the psoas muscle, in which it spreads down towards the iliac fossa, and into the thigh, passing beneath Poupart's ligament, posterior and lateral to the femoral vessels. The communication between the pelvis and the thigh is often very narrow, so that the abscess cavity has to some extent the shape of an hour-glass. The pus may reach the surface in the region of the saphenous opening, or may spread farther down the thigh under cover of the deep fascia. In some cases it is liable to be mistaken for a femoral hernia, as the swelling becomes smaller when the patient lies down, and has an impulse on coughing.

Lumbar Abscess.—Sometimes the pus travels along the posterior branches of the lumbar vessels and nerves to the lateral border of the sacro-spinalis (erector spinae) and comes to the surface in the space between the edges of the latissimus dorsi and external oblique muscles—the triangle of Petit.

In rare cases it passes through the sacro-sciatic foramen and forms a swelling in the buttock (sub-gluteal abscess); or it may pass through the obturator foramen and reach the adductor region of the thigh or even the perineum.

Lumbo-sacral Region.—Pott's disease in the lumbo-sacral region usually affects adults, and, on account of the breadth of the vertebral bodies and the limited range of movement in this segment of the spine, is seldom accompanied by marked symptoms or deformity. The diagnosis, therefore, is often difficult, unless good skiagrams are available. The disease may be associated with pain in the distribution of the sciatic nerve, which is liable to be mistaken for sciatica. Single or double iliac abscess frequently forms without the patient showing any characteristic signs of spinal disease. When the disease begins in childhood it may induce a permanent deformity of the pelvis, the conjugate diameter at the brim being increased, while the transverse diameter at the outlet is diminished—kyphotic pelvis, and, in females, this may lead to complications in parturition.

Tuberculous Disease of the Sacro-iliac Joint.—This condition may occur as a primary affection, but is much more frequently secondary to disease in the ilium, sacrum, or lower lumbar vertebrae, and is most common in adolescents and young adults of the male sex. It is attended with pain in the lumbar region, and sometimes in the buttock and along the course of the sciatic nerve. The pain is aggravated by movements, especially such as involve sudden and violent contraction of the lumbar and abdominal muscles, for example, coughing, sneezing, or straining during defecation. Tenderness is elicited on making pressure over the joint, on pressing together the iliac bones, or on attempting to abduct the limb while the pelvis is fixed. The muscles of the buttock and thigh are wasted. As any attempt to bear weight on the affected limb causes pain, the patient walks with a limp, and to save the joint he assumes an attitude which is characteristic: he throws his weight on the sound limb, leans forward, using a stick for support, tilts the affected side of the pelvis downwards, and flexes the hip and knee-joints of the diseased limb. The anterior superior spine is unduly prominent on the affected side, and the limb appears to be lengthened. Sooner or later, in most cases, an abscess forms, and the pus may reach the surface over the posterior aspect of the joint. When the pus forms in front of the joint, it may spread laterally in the iliac fossa as an iliac abscess or may gravitate downwards in the hollow of the sacrum and emerge on the buttock through the sacro-sciatic foramen—sub-gluteal abscess. Sometimes it passes into the ischio-rectal fossa or into the perineum. The presence of an abscess in the pelvis may sometimes be recognised on rectal examination. The appearance of an abscess is sometimes the first thing to draw attention to the condition.

As pain across the small of the back and along the course of the sciatic nerve may be among the early symptoms of sacro-iliac disease, the condition is liable to be mistaken for lumbago or for sciatica. From hip disease it is recognisable by noting that the movements of the hip-joint are not restricted. It is not always possible without the aid of skiagrams to differentiate sacro-iliac disease from disease of the lumbar spine, and the two conditions sometimes coexist.

The prognosis is unfavourable, particularly in cases complicated by extensive disease of the ilium with abscess formation and mixed infection.

Treatment.—In early cases the patient should use crutches and wear a patten on the foot of the sound side; in more advanced cases he must be confined to bed, and have absolute rest to the joint secured by means of extension applied to both legs, or by other apparatus. In children a double Thomas' splint or Stiles' abduction frame is a convenient appliance. Counter-irritation by blisters or the actual cautery may be had recourse to in dry cases in which pain is a prominent feature. If operative treatment becomes necessary, as it may, for removal of a sequestrum, access to the seat of disease is obtained by removing the posterior portion of the iliac bone. Cold abscess is treated on the usual lines.

Syphilitic Disease of the Vertebrae.—All the clinical features of Pott's disease may be simulated by gummatous disease of the vertebrae. This is usually met with in adults who have suffered from acquired syphilis; it is most common in the upper cervical vertebrae, and begins on the anterior surface of the bodies. The onset is more sudden than that of tuberculous caries, and the progress more rapid. The bone is early and extensively destroyed, but abscess formation is rare. Severe nocturnal pains are complained of, and some degree of angular deformity may develop. In almost all cases other evidence of tertiary syphilis is present, and this, together with the history and the effects of anti-syphilitic treatment, aids in diagnosis. The local treatment is carried out on the same lines as for tuberculous disease.

Malignant Disease of the Vertebrae.—Sarcoma is the most important of the primary tumours met with in the vertebral column. It gives rise to symptoms which are liable to be mistaken for those of Pott's disease or of arthritis deformans. The pain, however, is more intense, and the disease progresses more continuously, and is uninfluenced by treatment. The changes in the vertebrae, as seen in skiagrams, are helpful in diagnosis. The growth may encroach upon the vertebral canal and cause pressure on the cord (p. 451). In the sacrum—the most common site—the tumour implicates the sacral nerves, and causes symptoms of intractable sciatica; and the real nature of the disease is often only detected on making a rectal examination.