Tuberculosis of the spine (and idiopathic scoliosis)

The spine is the most common and the most dangerous site for skeletal tuberculosis. It takes two forms: (1) In the first, the patient's general symptoms are mild. The infection usually starts in the anterior part of a disc, and spreads to the adjacent surface of the body of a vertebra, or to two adjacent ones. It seldom involves his neural arches. The result is that, as the bodies of his vertebrae collapse, his spine angles forwards to produce a kyphus (an increase in the normal convex curve of the spine: a scoliosis is a lateral curvature). The shape of his spinal deformity depends on how many of his vertebrae are diseased. Commonly, as his deformity gets worse, a sharp angle (the gibbus) appears. Uncommonly, the destruction is not symmetrical, so that his spine rotates. (2) In the second form his general symptoms are more severe, several of his vertebrae are involved widely in his spine (including perhaps some in his neck), and his disc spaces may not be narrowed.

His first symptom is pain in his back, and his first sign is increasing kyphosis. Later, pus from his diseased vertebrae may track along tissue planes to present as a cold abscess in unexpected places, particularly in his groin (psoas abscess). He may become paraplegic (29.4a).

In a child spinal tuberculosis is an important cause of back pain. He will probably be unwell and have lost weight, but not always so. He may resent examination, be tender over his low thoracic or upper lumbar spine, and show any of the signs seen in adults.

Give him chemotherapy as an outpatient, without applying a plaster jacket. The former practice of giving all patients with spinal tuberculosis a plaster jacket is now outmoded. You will find that his spine will heal quicker if you let his vertebrae collapse down and fuse. As it does so, his pain will go and his vertebrae will recalcify. His deformity will probably increase by about 5[de] to 25[de] during treatment. Only extensive surgery, in the most expert centres, gets better results than this. Its main advantage is that it establishes bony fusion in 2 years, instead of in 4 years.

Idiopathic kyphoscoliosis is one of the differential diagnoses of a tuberculous spine. It is a disease of unknown cause, in which a child's spine slowly develops a curve. It may start as early as 3 years, but it more often starts at 7 or 8; it progresses most rapidly between the ages of 12 and 14, and gets worse until he stops growing. If possible, refer him to a special centre, which can fit him with a Milwaukee or similar brace, and if necessary fuse his spine at the appropriate time. If you cannot refer him, reassure his parents that, although he will always be a hunchback, he will be normal in most other ways. Spinal compression is rare, but a moderate or severe lesion will affect the function of his lungs by reducing the size of his thoracic cage.

SPINAL TUBERCULOSIS EXAMINATION. Examine a patient as in Section 27.8. Examine him from the side; look and feel for: (1) a kyphus, (2) reduced movement of his lumbar spine, (3) cold abscesses in his paraspinal area, loin, and groin, (4) sinuses. Test the reflexes in his legs, and their tone, power, and sensation.

X-RAYS are critical, see Fig. 29-3. X-ray his chest also.

Look for: (1) Narrowing or obliteration of a joint space, involving at least two vertebral bodies and the disc between them (this is the typical late picture). Sometimes several vertebrae disappear into the space normally occupied by one or two. So count his vertebral spines, because these may be all that is left when his vertebral bodies have been destroyed. (2) Look for forward collapse of his spine. (3) You may also see: (a) the shadow produced by a paravertebral abscess in his thoracic region (this strongly suggests tuberculosis, but it can be produced by staphylococcal and other forms of bacterial osteitis), and (b) calcification in his psoas sheath, showing that a psoas abscess is forming. Evidence of a paravertebral abscess increases the probability of tuberculosis being the cause, but is not necessary for diagnosing it. (4) Osteophytes and bridging (rare). If you do see bridging, it is more likely to be due to late staphylococcal infection.

SPECIAL TESTS. The ESR is useful and may be very high. A falling ESR is an indication of response to treatment, but is less important than an improvement in his clinical condition, as indicated by decreasing pain and tenderness.

THE DIFFERENTIAL DIAGNOSIS [s7]OF A TUBERCULOUS SPINE Suggesting pyogenic osteitis[md]a more rapid onset, less bone destruction, and a higher temperature. Confirming the diagnosis may have to depend on the aspiration and examination of pus from his spine, or on costotransversectomy, see Section 29.4a.

Suggesting poliomyelitis[md]weak, wasted, flaccid legs. If polio involves his spine, it is almost sure to involve his legs too. Scoliosis rather than kyphosis.

Suggesting idiopathic scoliosis[md]the curve is smooth, with no gibbus, or muscle-wasting. Apart from the curved shape of his spine, there are no other signs; his X-rays are normal, and no vertebrae are destroyed. The disease starts in childhood.

Suggesting a congenital hemivertebra causing scoliosis (usually mild)[md]half of one of his vertebrae is missing. The half which remains forms the apex of the curve. On an X-ray this is almost triangular, its edges are smooth and well formed, and there are no signs of disc destruction in the vertebra above or below. This kind of scoliosis does not progress with age, and needs no treatment.

Suggesting kyphoscoliosis due to lung disease[md]a previous history of empyema. By making his lung collapse, an empyema may collapse his thoracic cage. Other causes of fibrosis of a lung, or pneumonectomy. His spine itself needs no treatment.

Suggesting secondary deposits[md]involvement of the bodies of his vertebrae without involvement of their discs. His serum alkaline phosphatase is raised. If the primary is in his prostate, his acid phosphatase will be raised also.

Suggesting a senile kyphosis[md]an old woman with osteoporosis of all, or most, of her spine, and normal discs, which bulge into her softened vertebrae. Her kyphus is gradual. Treatment is difficult (27.8).

Suggesting Burkitt's lymphoma[md]the patient is a child. In the endemic areas this is the commonest cause of paraplegia in children (32.3).

TREATMENT. Give him chemotherapy, as in Section 29.1. If his back is painful at first, admit him for bed rest, but allow him up if he wishes. If he can walk, encourage him to do so.

Warn him that he must continue with his drugs, and that they will take some months to have much effect. During this time, he may find his kyphoscoliosis getting worse, before it stabilizes. If he thinks your treatment is not working, he may default, and go to a traditional practitioner. If he does default, do all you can to trace him.

DIFFICULTIES [s7]WITH A TUBERCULOUS SPINE See also Section 29.3.

If his CERVICAL SPINE is involved, treat him with an orthopaedic collar, or failing this, a plaster cuirasse (64-10) and chemotherapy. His spinal canal is larger in his neck than in his thoracic region, so his spinal cord is less likely to be compressed.

If he complains of CLUMSINESS, WEAKNESS, OR INCOORDINATION, he is becoming paraplegic, so see below.