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.

_Secondary cancer_ is a common disease, particularly in cases of advanced scirrhus of the breast. It leads to extensive softening of the bodies of the vertebrae, so that they yield under the weight of the body, as in Pott's disease. Clinically it is associated with severe pain in the region of the vertebrae affected, and along the course of the nerves emerging in the neighbourhood. If paralysis occurs from the cancerous bodies pressing upon the cord (_paraplegia dolorosa_), it is of rapid development, often becoming complete in a few hours. When the cervical cord is compressed all four limbs are paralysed, and from interference with respiration, the condition is fatal within a few days.

#Actinomycosis#, #Blastomycosis#, and #Hydatid Cysts# also occur in the vertebrae, and are difficult to diagnose from tuberculous disease.

#Typhoid Spine.#--An acute infective condition of the vertebrae, intervertebral discs, and spinal ligaments occasionally occurs during convalescence from typhoid fever. The lumbar region is most frequently affected, and the X-rays reveal inflammatory changes in the bones, disappearance of the discs, and, in the later stages, deposits of new bone leading to synostosis of adjacent vertebrae. The onset, which may be gradual or sudden, is attended with intense pain, and tenderness over the affected vertebrae. The temperature is raised, and other signs of an acute infective process are present. In a few cases there are symptoms of involvement of the membranes and cord. With prolonged rest and immobilisation of the spine the inflammation usually subsides, but sometimes it goes on to suppuration.

#Hysterical Spine.#--This term is applied to a functional affection of the spine occasionally met with in neurotic females between the ages of seventeen and thirty, and liable to be mistaken for Pott's disease. The patient complains of pain in some part of the spine--usually the cervico-thoracic or thoracico-lumbar region--and there is marked hyperaesthesia on making even gentle pressure over the spinous processes. As the patients are usually thin, the pressure of the corset is apt to redden the skin over the more prominent vertebrae, and give rise to an appearance which at first sight may be mistaken for a projection. The general condition of the patient, the freedom of movement of the vertebral column, and the entire absence of rigidity, are sufficient to exclude tuberculosis. The condition is treated on the same lines as other hysterical affections.

#Acute osteomyelitis# of the vertebrae is a rare affection, and is met with in young subjects. It attacks the more mobile portions of the spine--cervical and lumbar--and may begin either in the bodies or in the arches. It is attended with extreme sensitiveness on movement, severe localised pain in the region of the vertebrae attacked, and a marked degree of fever. Pus usually forms rapidly, but, being deeply placed, is not easily recognised unless it points towards the surface. The infection is liable to spread to the meninges of the cord and give rise to meningitis, particularly when the disease begins in the arches. A milder form occurs, in which the main incidence is on the periosteum; the symptoms are less severe, it does not tend to suppurate, and is usually recovered from. The treatment consists in applying extension to the spine and in opening any abscess that may be detected. The suppurative form usually proves fatal, and, indeed, is often only diagnosed on post-mortem examination.

#Arthritis Deformans.#--This disease usually begins between the ages of thirty-five and forty, and attacks men who follow some laborious occupation which involves exposure to cold and wet. It is met with, however, in women who lead a sedentary life. There is sometimes a recent history of gonorrhoea, rheumatism, or other toxic disease, and occasionally the condition follows upon injury. The discs disappear, osteophytic outgrowths develop at the margins of the bodies and in connection with the transverse processes, and bridge across the space between neighbouring vertebrae (Fig. 218). The articulations between the ribs and the vertebrae show similar changes, and the ligaments of the several joints tend to undergo ossification, so that the bones are fused together.

In the early stage the patient complains of pain and stiffness in the back; later the spine becomes rigid, and gradually develops a kyphotic curve, sometimes accompanied by lateral deviation. In some cases, the curvature of the spine assumes an extreme type, the shoulders are rounded, and the head depressed, the face approximating the sternum, so that to see an object such as a picture on a wall, the patient must turn his back to it. The chest is flattened and restricted in its movements, with the result that respiration is embarrassed and becomes almost entirely abdominal. The muscles of the back, shoulders, and hips undergo atrophy, and may exhibit tremors, and the deep reflexes become exaggerated. The nerves are liable to be pressed upon as they pass through the intervertebral foramina, and this gives rise to pain and other disturbances of sensation in their area of distribution. These pains may simulate those associated with renal or gastro-intestinal affections.

The disease may simulate tuberculous caries or malignant disease. The changes in the bones are demonstrated by the use of the X-rays.

The treatment is carried out on general principles (Volume I., p. 530), but it is seldom possible to do more than arrest the progress of the disease.

#Coccydynia# is the name applied to a condition in which the patient experiences severe pain in the region of the coccyx on sitting or walking, and during defecation. The pathology is uncertain. In some cases there is a definite history of injury, such as a kick or blow, causing fracture of the coccyx, or dislocation of the sacro-coccygeal joint. These lesions have also been produced during labour. In other cases the pain appears to be neuralgic in character, and is referable to the fifth sacral and the coccygeal nerves, or to the terminal branches of the sacral plexus distributed in this region. The affection is almost entirely confined to females, and the patients are usually of a neurotic type. On rectal examination the coccyx is exceedingly tender, and it is sometimes found to be less movable than normal, and unduly arched forward. When medicinal treatment fails to give relief, the coccyx may be excised.

#Tumours of the Spinal Cord and Membranes.#--Tumours may develop in the substance of the cord (_intra-medullary_), in the membranes (_meningeal_), or in the tissues between the dura and the bone (_extra-dural_); or the cord may be pressed upon by a tumour originating in the vertebrae. It is seldom possible to diagnose the nature of a tumour before operation, and it is often difficult to determine in which of the above situations it has originated.

Tumours growing _in the substance of the cord_ are nearly as common as extra-medullary growths, and as the growth is usually sarcoma, glioma, tuberculoma, or gumma, and infiltrates the cord, it is seldom capable of being removed by operation.

The great majority of _meningeal_ tumours are primary sarcomas, and in about 25 per cent. of cases they are multiple. Hydatid cysts and fibromas are also met with in this situation, and they too may be multiple.

_Extra-dural_ growths are comparatively rare. The forms usually met with are sarcoma and lipoma.

These extra-medullary tumours seldom infiltrate the cord; they simply compress it, and should be subjected to operative treatment before secondary changes are produced in the cord.

The _symptoms_ vary according as the tumour presses on the nerve roots, on one half, or on both halves of the cord. Pressure on nerve roots is a characteristic sign in extra-medullary growths. It gives rise to pain, which, according to the level of the tumour, passes round the trunk (girdle-pain), or shoots along the nerve-trunks of the upper or lower limbs.

When the cord is pressed upon, intense neuralgic pain related to the segment first involved is one of the earliest symptoms, particularly in extra-medullary tumours. The pain is at first unilateral, but later becomes bilateral--a point of importance in diagnosis. The painful areas are anaesthetic, but the anaesthesia does not always reach to the level of the lesion. There may be a zone of hyperaesthesia at the upper limit of the anaesthesia, or in the area corresponding to the roots on which the tumour is situated, but there is never diffuse hyperaesthesia (V. Horsley). In intra-medullary tumours the pain is less severe, it is rarely an initial symptom, and is seldom referable to individual nerve roots.

The next symptom to appear is motor paresis, followed by complete paralysis, and later by contracture of the paralysed muscles--_spastic paraplegia_. In intra-medullary tumours the paraplegia is usually less complete than in those that are extra-medullary. When only one lateral half of the cord is pressed upon, the motor paralysis and loss of ordinary sensation are on the same side as the tumour, and the loss of the sense of pain and of the temperature sense is on the opposite side. Retention of urine accompanies the onset of paralysis, and later gives place to incontinence. The rectum becomes paralysed, and cystitis and pressure sores develop.

Anti-syphilitic treatment should be employed in the first instance to exclude the possibility of the lesion being of the nature of a gumma. Radical operative treatment is contra-indicated in intra-medullary and in metastatic growths, but decompressive measures may be employed for the relief of pain. In meningeal and extra-dural tumours, however, in view of the hopeless prognosis if the condition is allowed to take its course, an attempt may be made to remove the tumour by operation. It is to be borne in mind that the lesion may be two or three segments higher than the complete anaesthesia would appear to indicate; the vertebral canal, therefore, should be opened about four inches above the level of the anaesthesia.

When the tumour is not removable, the patient's suffering may sometimes be alleviated by resecting the posterior roots of the nerves emerging in the vicinity of the lesion.

#Chronic Spinal Meningitis.#--Victor Horsley (1909) described by this name a condition which gives rise to symptoms closely simulating those of a tumour of the cord. He believes it to consist in a pachymeningitis combined with a certain degree of sclero-gliosis of the periphery of the cord. The theca is greatly distended over a variable extent of the cord; the cerebro-spinal fluid is increased in quantity and is under considerable tension; and the cord itself presents a shrunken appearance. Sometimes there is thickening of the arachno-pia and matting of the nerve roots. The condition appears to begin in the lower part of the cord, and to spread up, usually as far as the mid-thoracic region. There is frequently a history of syphilis, sometimes of recent gonorrhoea, but in some cases no cause can be assigned for the lesion.

_Clinical Features._--This affection is almost always met with in adults, and the earliest symptoms are pain and weakness in the legs, and sometimes a slight kyphotic projection of the spinous processes. The loss of power, which is sometimes attended with spasticity, usually manifests itself in one leg first, and later affects the other; it is progressive, and ultimately ends in complete paraplegia. The pain is not confined to the region supplied by any one nerve root, but affects a diffuse area, and the patient complains also of a sensation of tightness in the limbs. There is never absolute anaesthesia, but there is relative anaesthesia for all forms of sensation, which extends as a rule as far as the sixth or eighth thoracic root.

There are no vaso-motor phenomena, and no tendency to the formation of pressure sores. Sometimes the patient complains of pain in the spine, but this is not aggravated by movement.

_Treatment._--The treatment recommended by Horsley consists in performing laminectomy, opening the theca, and washing it out with 1 in 1000 mercurial lotion. After the wound has healed, mercurial inunction over the spine is employed to hasten the absorption of inflammatory products. The administration of anti-syphilitic drugs has not proved beneficial.

#Acute Spinal Meningitis.#--The spinal membranes may become implicated by direct spread in cases of acute intra-cranial lepto-meningitis, or they may be infected from without--for example, in gun-shot injuries or in cases of spina bifida.

When the infection spreads from the cranial cavity, the cerebral symptoms dominate the clinical picture, but evidence of involvement of the membranes of the cord may be present in the form of rigidity of the cervical muscles with retraction of the neck; deep-seated pain in the back, shooting round the body (girdle-pain) and down the limbs; painful cramp-like spasms in the muscles of the back and limbs, with increased reflex excitability, sometimes so marked as to simulate the spasms of tetanus.

When the theca of the cord is directly infected the spinal symptoms predominate at first, but as the condition progresses it involves the cerebral membranes, and symptoms of acute general lepto-meningitis ensue.

Once the condition has started little can be done to arrest its progress, but the symptoms may be relieved by repeated lumbar puncture.

#Spinal Myelitis.#--The term "myelitis" is applied to certain changes which occur in the spinal cord as a result, for example, of haemorrhage into its substance (_haemorrhagic myelitis_); or of pressure exerted on it by fragments of bone, blood-clot, tuberculous material, or new growths (_compression myelitis_).

In another group of cases myelitis is a result of the action of organisms or their toxins. Syphilis is a common cause, but the condition may follow on infections with ordinary pyogenic cocci, pneumococci, the influenza bacillus or the bacillus coli.

In addition to the use of anti-syphilitic remedies, or of sera directed to neutralise the toxins of the causative organism, attention must be directed to the bladder, and steps taken to prevent cystitis and the formation of bed-sores.

CONGENITAL DEFORMITIES OF THE SPINE

#Spina Bifida.#--Spina bifida is a congenital defect in certain of the vertebral arches, which permits of a protrusion of the contents of the vertebral canal. It is due to an arrest of development, whereby the closure of the primary medullary groove and the ingrowth of the mesoblast to form the spines and laminae fail to take place. The cleft may implicate only the spinous processes, but as a rule the laminae also are deficient. The defect usually extends over several vertebrae (Fig. 219). While the protrusion varies much in size, there is no constant ratio between the dimensions of the swelling and the extent of the defect in the neural arches.

The condition is comparatively common, being met with in about one out of every thousand births. It is most frequent in the lumbar and sacral regions (Fig. 219), but occurs also in the cervical (Fig. 220) and thoracic regions. It is not uncommon to find spina bifida associated with other congenital deformities such as hydrocephalus, club-foot, and extroversion of the bladder.

_Varieties._--Four varieties are usually described according to the character of the protrusion. They are analogous, to a certain extent, to the varieties of cephalocele (p. 387). (1) _Spinal meningocele_, in which only the membranes, filled with cerebro-spinal fluid, are protruded. (2) _Meningo-myelocele_, the form most commonly met with clinically, in which the cord and some of the spinal nerves are protruded, and spread out over the inner aspect of the sac (Figs. 219, 220). (3) _Syringo-myelocele_, in which there is a dilatation of the central canal in the protruded part of the cord. In these three forms the protrusion may be covered by healthy skin, or by a thin, smooth, translucent membrane through which the contents are visible. Frequently this thin covering sloughs or ulcerates, and permits the cerebro-spinal fluid to drain away. (4) In the _myelocele_, this skin, as well as the vertebral arches and membranes, is absent, and the cord lies exposed on the surface. This form is comparatively common, but as the infants are either dead born or die within a few days of birth, it seldom comes under the notice of the surgeon.

_Clinical Features._--The presence of a swelling in the middle line of the back, which has existed since birth, and which contains fluid and increases in size and tenseness when the child cries, renders the diagnosis of spina bifida easy. The defect in the bone may be seen in skiagrams. The swelling is usually sessile, but may be pedunculated; it is usually possible to palpate the edges of the gap in the bones. It may be reduced in size by making gentle pressure over it, and in young children this may cause a bulging of the fontanelles. This test, however, must be employed with caution, as it is liable to induce convulsions. A meningocele, as it contains no nerve elements, may be translucent. In a meningo-myelocele the shadows of the cord and nerves stretched out in the sac may be recognised. The presence of the cord is sometimes indicated by a median furrow, and after withdrawal of some of the fluid the cord can sometimes be palpated. It is, however, often difficult to distinguish between a meningocele and meningo-myelocele.

Sometimes there are no nervous disturbances, and this is especially the case when the defect is in the lower lumbar and sacral regions below the termination of the cord. In most cases, however, there are paralytic symptoms referable to the lower extremities, the bladder, and the rectum, and there may also be trophic disturbances in the parts below. Paralytic symptoms may be absent during infancy, and develop during childhood or adolescence.

_Prognosis._--Comparatively few children born with spina bifida survive longer than four or five years. The great majority die within a few weeks of birth, death being due to the escape of cerebro-spinal fluid, or to spinal meningitis following on infection. The condition in some cases remains stationary for years, but spontaneous disappearance is rare.

_Treatment._--The more severe forms of spina bifida only call for palliative treatment, which consists in protecting the protrusion against infection and applying a sterilised dressing and a supporting bandage. A meningocele may be tapped with a fine needle passed through healthy skin, and the empty sac compressed by a pad of wool and an elastic bandage.

Operative treatment is seldom to be recommended in a young child unless it is otherwise viable and the swelling is increasing rapidly and threatening to burst, and there is reason to believe that the paralysis is due to pressure. The immediate results of operation are usually satisfactory, but in a large proportion of cases the child subsequently develops hydrocephalus, from which it ultimately succumbs. The hope of improvement in the motor symptoms after operation depends on the site of the spina bifida; above the twelfth thoracic vertebra there is no prospect of improvement; below this level, inasmuch as it is the tip of the conus or the cauda equina that is involved, there may be regeneration of nerve fibres and return of power in the lower extremities, and control of the sphincters may be regained. Murphy has practised resection of cicatricial or atrophied portions of the cauda, with end-to-end suture.

The term #spina bifida occulta# is applied to a condition in which there is no protrusion of the contents of the vertebral canal, although the vertebral arches are deficient. The skin over the gap is often puckered and adherent, and is frequently covered with a growth of coarse hair.

A mass of fat may project towards the surface, and when situated in the lumbo-sacral region may suggest a caudal appendage or tail (Fig. 222).

The clinical importance of spina bifida occulta lies in the fact that it is sometimes associated with congenital club-foot, and with nerve symptoms, in the form of sensory, motor, and trophic disturbances referable to the lower limbs, such as perforating ulcer, and to the sphincters. These nerve symptoms usually result from the presence of a tough cord composed of connective tissue, fat, and muscle, stretching from the skin through the vertebral canal to the lower end of the spinal cord. As this strand of tissue does not grow in proportion with the body, in the course of years it drags the cord against the lower border of the membrana reuniens, which closes in the vertebral canal posteriorly. These symptoms may be relieved by the removal of this strand of tissue from the gap in the vertebral arches, or by incising the membrana reuniens.

#Congenital Sacro-coccygeal Tumours--Teratoma.#--Many varieties of congenital tumours are met with in the region of the sacrum and coccyx. The majority are developed in relation to the communication which exists in the embryo between the neural canal and the alimentary tract--the post-anal gut or neurenteric canal. Some are evidently of bigerminal origin, and contain parts of organs, such as limbs, partly or wholly formed, nerves, parts of eyes, mammary, renal, and other tissues.

Among other tumours met with in this region may be mentioned: the congenital _lipoma_--a small, rounded, fatty tumour which often suggests a caudal appendage (Fig. 222); the _sacral hygroma_, which forms a sessile cystic tumour growing over the back of the sacrum, and is believed to be a meningocele which has become cut off _in utero_ by the continued growth of the vertebral arch; dermoids, sarcoma, and lymphangioma.

The _treatment_ consists in removing the tumour, as from its situation it is exposed to injury, and this is liable to be followed by infection. From the position of the wound, and the fact that many of these tumours extend into the hollow of the sacrum and therefore necessitate an extensive dissection, there is considerable risk from infection, especially in young children. The risk is increased when the tumour communicates with the vertebral canal.

#Congenital Sacro-coccygeal Sinuses and Fistulae.#--The _post-anal dimple_, a shallow depression frequently observed over the tip of the coccyx, may be due to traction exerted on the skin at this spot by the remains of the neurenteric canal, or by the caudal ligament of Luschka. Sometimes the integument is retracted to such an extent that one or more _sinuses_ are formed, lined with skin which is furnished with hairs, sweat, and sebaceous glands. The bursting of a dermoid, or its being incised in mistake for an abscess, may result in the formation of such a sinus, which fails to heal and may persist for years.

In some cases the depression communicates with the vertebral canal, constituting a complete _sacro-coccygeal fistula_, which may be lined with cylindrical or ciliated epithelium.

From the accumulation of secretions and subsequent infection, these conditions may be associated with a persistent offensive discharge, and they are liable to be mistaken for ano-rectal fistulae. They are best dealt with by complete excision, and as primary union cannot be expected, the wound should be treated by the open method.