_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 const.i.tutes 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 s.p.a.cing, 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.
[Ill.u.s.tration: FIG. 213.--Radiogram of Child"s Thorax, showing spindle-shaped shadow at site of Pott"s disease of fourth, fifth, and sixth thoracic vertebrae.]
_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 (a.n.a.lgesia) 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 p.r.o.ne 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 rec.u.mbent posture and in the att.i.tude 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 rec.u.mbent posture to one year at the most.
The immobilisation of the rec.u.mbent spine in the att.i.tude 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 subst.i.tutes, but _Phelps" box_ has been discarded because it fails to secure immobilisation of the spine.
When the stage of _convalescence_ is arrived at, and rec.u.mbency 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 subst.i.tuted 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 dema, 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 ill.u.s.trating 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 ma.s.s 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 const.i.tute 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).
[Ill.u.s.tration: FIG. 214.--Att.i.tude of patient suffering from Tuberculous disease of the Cervical Spine. The swelling on the left side of the neck is due to a retro-pharyngeal abscess.]
An abscess may form between the vertebrae and the wall of the pharynx--_retro-pharyngeal abscess_--the pus acc.u.mulating 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 r.e.c.t.u.m 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).
[Ill.u.s.tration: FIG. 215.--Thomas" Double Splint for Tuberculous disease of Spine.]
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-pa.s.sages 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 sophagus 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.
[Ill.u.s.tration: FIG. 216.--Hunch-back Deformity following Pott"s disease of Thoracic Vertebrae.
(Photograph lent by Sir George T. Beatson.)]
_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 pa.s.s 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, pa.s.sing 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 a.s.sociated 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 a.s.sume a characteristic att.i.tude--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.
[Ill.u.s.tration: FIG. 217.--Att.i.tude in Pott"s disease of Thoracico-lumbar Region of Spine.]
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 b.u.t.tocks and into the legs. If the cord is pressed upon at the level of the lumbar enlargement the a.n.a.l 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, pa.s.sing 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-gla.s.s. 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 s.p.a.ce between the edges of the latissimus dorsi and external oblique muscles--the triangle of Pet.i.t.
In rare cases it pa.s.ses through the sacro-sciatic foramen and forms a swelling in the b.u.t.tock (_sub-gluteal abscess_); or it may pa.s.s 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 a.s.sociated 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 s.e.x. It is attended with pain in the lumbar region, and sometimes in the b.u.t.tock 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 b.u.t.tock 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 a.s.sumes an att.i.tude 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 b.u.t.tock through the sacro-sciatic foramen--_sub-gluteal abscess_. Sometimes it pa.s.ses 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.