Tuberculosis of the spine is the most prevalent form of bone and joint tuberculosis, accounting for 40% to 50% of cases. In recent years, the incidence has decreased due to the development of public health and the advancement of anti-tuberculosis drugs, but it still ranks first among inflammatory diseases of the spine. The vast majority of spinal tuberculosis is vertebral tuberculosis, and simple arch tuberculosis is rare, which is related to the predominance of cancellous bone in the vertebral body, high load, high strain, low muscle attachment, poor blood supply, and the trophoid artery of the vertebral body is mostly the terminal artery.
The most frequent sites of disease are the lumbar spine, followed by the thoracic spine, the thoracolumbar segment occupies the third place, the cervical spine, the sacrococcygeal spine at least, there are also statistics: thoracic spine (40.3%), lumbar spine (35.97%), followed by the thoracolumbar spine (12.77%) and lumbosacral spine (7.36%) and so on. About 3% to 7% of the cases have two vertebral lesions separated by a disease-free vertebral body, which is called jumping spinal tuberculosis. Tuberculosis of the spine is more common in children and adolescents, and the older the age, the less the incidence, which may be related to the immunity of the body.
In the last 20 years or so, some basic concepts in the understanding and treatment of spinal tuberculosis disease have become more advanced due to the intensive progress in basic and clinical research on spinal surgery and significant advances in the study of antituberculosis drugs. The basic principles and techniques of anti-TB and surgical lesion removal are also undergoing significant changes with the development of surgical techniques and biomaterials.
I. Typology and evolution of spinal tuberculosis lesions occur mostly in the vertebral body, with a few in the vertebral plate, arch, spinous process and transverse process.
(A) Central or juvenile type The pediatric vertebral body is surrounded by cartilage components, and the central ossification part of the lesion may have collapsed early vertebral space after development.
(ii) Marginal type, also called epiphyseal or adult type, occurs in older children or adults, starting from the epiphysis at the upper or lower edge of the vertebral body, and the lesion often rapidly destroys the intervertebral soft tissue, narrowing or disappearing the intervertebral space, with the upper and lower vertebral bodies connected.
(iii) Anterolateral or subperiosteal type Also occurs in adults and is located under the anterior vertebral ligament and often spreads to involve adjacent vertebrae above and below.
(iv) Accessory tuberculosis such as tuberculosis of the transverse process, vertebral plate, pedicle, or spinous process is less common.
Vertebral lesions have bone destruction and necrosis due to circulatory disorders and tuberculosis infection, with case-like changes and abscess formation, and collapse of the vertebral body due to lesions and weight bearing, resulting in curvature of the spine, elevation of the spinous process, and hump deformity of the back, which is particularly evident in thoracic spine tuberculosis. Due to collapse of the vertebral body, dead bone, granulation tissue and abscess formation, paraplegia can occur due to spinal cord compression, which occurs more frequently in the cervical and thoracic spine. Bone destruction and cold abscesses form under the anterior longitudinal ligament of the spine, which may cross the ligament to the anterior fascial space of the spine and may spread to sites far from the lesion due to gravity. Cervical tuberculosis abscesses may appear in the anterior cervical spine making the posterior pharyngeal wall bulge, which may cause swallowing or breathing difficulties; on both sides of the neck they may appear subcutaneously at the posterior border of the sternocleidomastoid muscle. Thoracic spine tuberculosis often forms prevertebral and paravertebral abscesses, which may also appear in the posterior mediastinal area or develop along the intercostal space toward the chest wall; development toward the spinal canal may cause paraplegia.
Lumbar tuberculosis abscesses often reach the pelvis and form lumbar muscle abscesses that spread down the iliopsoas muscle to the inguinal or medial femur, from the posterior femur to the greater trochanter, along the broad fascial tensor and iliotibial bundle to the lower lateral femur; or spread backward to the lumbar triangle. These abscesses, because they do not show signs of acute inflammation, are called cold abscesses. In the process of improvement of spinal tuberculosis, the destructive products of the lesion, such as abscesses and dead bone, can be gradually absorbed, while there is fibrous tissue filling and repair, and finally fibrous healing and bony healing are formed, and the course of the disease is long. However, through active treatment, the course of the disease can be greatly shortened.
II. Clinical features
(a) Systemic symptoms The onset of the disease is insidious, and the date of onset is not clear. Patients have symptoms of generalized tuberculosis toxicity such as lethargy and weakness, loss of appetite, low fever in the afternoon, night sweats and emaciation. Occasionally, a few cases of acute exacerbation with a temperature of about 39°C are seen, which are mostly misdiagnosed as severe colds or other acute infections. On the contrary, there are cases without the above mentioned systemic symptoms such as low-grade fever, and only dull pain or radiating pain in the affected area can be easily misdiagnosed as other diseases.
(B) Local symptoms
1. Pain: Dull pain in the affected area and systemic symptoms such as low fever appear more often at the same time, aggravated by activities, vibration, coughing and sneezing, and alleviated after bed rest; the pain increases at night, and can radiate along the spinal nerve, from the upper cervical spine to the posterior occipital region, from the lower cervical spine to the shoulder or arm, and from the thoracic spine to the upper and lower abdomen along the intercostal nerve, and is often misdiagnosed as cholecystitis, pancreatitis, appendicitis, etc. The lower thoracic spine 11-12 may radiate along the inferior gluteal nerve to the lower back or buttocks, and for this reason, only lumbar spine films are often taken during X-ray examination, so that lesions of the lower thoracic spine are often missed. Lumbar spine lesions along the lumbar plexus mostly radiate to the front of the thigh, occasionally involving the back side of the leg, and are easily misdiagnosed as intervertebral disc prolapse.
2, postural abnormalities: caused by pain resulting in spasm of the paravertebral muscles. Patients with cervical tuberculosis often have a sloping neck, forward head tilt, shortened neck and hands holding the jaw. The posture of chest and abdomen is common in the thoracolumbar or lumbosacral spine structure. Normal people can bend over to pick up things, but because of the disease can not bend over but bend the hip and knee, one hand on the knee and the other hand to pick up things on the ground, called a positive pick-up test. Young children can not extend the waist, can be made to lie prone, the examiner lift their feet with their hands, the normal spine is curved natural back extension, and children with disease intervertebral fixation or paraspinal muscle spasm, the waist can not back extension.
3, spinal deformity: the cervical and lumbar spine to note whether the physiological protrusion disappeared, the thoracic spine has increased physiological protrusion. From top to bottom, look for abnormal protrusion of each spinous process, especially limited angular posterior protrusion, which is mostly seen in spinal tuberculosis, and young vertebral epiphyseal chondromalacia, ankylosing spondylitis, poor posture, etc. into arcuate posterior protrusion and round back.
4, cold abscess: 70% to 80% of spinal tuberculosis at the time of consultation is complicated by cold abscesses, located deep in the spinal paravertebral abscesses by X-ray radiography CT or MRI can be shown. Abscesses may flow along the myofascial space or neurovascular bundle to the surface.
Circumferential spine lesions may have abscesses in the posterior pharyngeal wall causing dysphagia or respiratory disturbances; abscesses in the middle and lower cervical spine appear in the anterior or posterior cervical triangle; abscesses in the lateral aspect of the vertebral body of thoracic vertebral tuberculosis present as tense spindle or columnar abscesses, which may flow along the intercostal neurovascular bundle to the thoracic back and occasionally penetrate into the lung, thoracic cavity, and rarely through the esophagus and thoracic aorta; abscesses in the thoracolumbar and lumbar spine may flow down along one or both iliopsoas muscle fascia or its interstitial The abscesses of the thoracolumbar spine and lumbar spine can be injected along one or both sides of the iliolumbar fascia or between their parenchyma downward in the retroperitoneum, occasionally penetrating into fixed organs such as the colon, downward without seeking upward to the iliac fossa, groin, buttocks or legs; the abscesses of the sacral spine are often gathered in front of the sacrum or along the pear-shaped muscle through the greater sciatic foramen to the vicinity of the greater trochanter of the femur, and it is helpful to master the pathway of cold abscess flow injection and its emergence site for diagnosis.
5.Sinus tract: cold abscess can extend to the body surface, which can be absorbed by itself after treatment or form a sinus tract by breaking down by itself. When the sinus tract is secondary to infection, the condition will be aggravated, treatment is difficult and prognosis is poor, so it should be avoided as much as possible. 6. Spinal cord compression signs Patients with spinal tuberculosis, especially above the cone of cervicothoracic tuberculosis, should pay attention to the presence of spinal cord compression signs and nerve dysfunction of the extremities for early detection of spinal cord compression complications.
Third, complications and manifestations of spinal tuberculosis complicating paraplegia is the most common complication
(a) Precursors of spinal tuberculosis before paraplegia.
1. Sensory disorders, such as patients complaining of a tightening sensation from the back to the forehead or abdomen, or abnormal sensation of ants crawling, numbness, or cold stimulation
2.Motor disorders: feeling of walking awkwardly, not obeying when moving the feet, stiffness of both lower limbs, stiffness, trembling, or weakness, easy to fall, etc.
3, sphincter dysfunction mainly bladder and rectal sphincter disorders, manifested as weakness, incontinence, etc.
4.Phytodysfunction such as dry, sweatless skin under the lesioned vertebrae, low skin temperature, touching the normal vertebrae or the nerves innervated by the lesioned vertebrae up and down, left and right, there is a distinct feeling of heat and cold.
(B) about 10% of the spinal nodules combined with paraplegia, should implement the prevention-oriented approach, the main measures for the active period of spinal tuberculosis adhere to non-weight bearing, adhere to bed and anti-TB drug therapy. If paraplegia has occurred, early and active treatment should be provided, and most of them can achieve good recovery. If the time is lost, the consequences are serious. If partial paralysis has already occurred, non-surgical treatment is usually given first, according to the care of paraplegia, absolute bed rest, anti-TB medication, improve the general condition, and strive for the best recovery; if no recovery is seen after 1 to 2 months, surgery should be performed as early as possible to release the tension, and if paraplegia develops rapidly or even completely, surgery should be performed as soon as possible, and it is not advisable to wait.
In cervical spine tuberculosis combined with paraplegia, or with cold abscess, early surgery should be performed. An incision can be made on the anterior side of the neck, entering between the anterior aspect of the sternocleidomastoid muscle and the internal carotid vein of the common carotid artery (or before the carotid sheath) to reveal and remove the lesion, dealing with both sides at once if necessary. In the thoracic spine surgery, we mostly use transverse rib resection lesion removal, or perform anterolateral anterior focal removal and decompression, and then make spinal fusion to stabilize the spine after the paraplegia is recovered and the general condition is improved.
Fourth, auxiliary examination
(a) X-ray in the early stage of the disease is mostly negative, X-ray early signs in most cases first paravertebral shadow expansion, with the anterior lower edge of the vertebral body involvement, and intervertebral narrowing, vertebral body bone thinning, paravertebral shadow expansion and dead bone, etc.. Vertebral bone destruction area <15mm in diameter cannot be shown on lateral radiographs, but can be detected on body radiographs with a destruction area of about 8mm in diameter. In vertebral cancellous bone or abscesses, large and small dead bones can be seen.
In central vertebral tuberculosis vertebrae, the intervertebral space is not significantly altered, making it difficult to distinguish from vertebral tumors; however, certain slow-growing tumors such as metastatic thyroid cancer, chordoma, and malignant lymphoma can show varying degrees of intervertebral stenosis, making it difficult to distinguish from epiphyseal vertebral tuberculosis. Usually in cases of vertebral tuberculosis, paravertebral shadow enlargement is mostly bilateral, except in patients who are old or will be cured. However, spinal tumors such as vertebral giant cell tumor, chordoma, malignant lymphoma and spinal metastasis of renal cancer are distinguished by unilateral or bilateral enlargement of the paravertebral shadow, especially limited to one side, when seen on orthogonal radiographs.
(B) CT examination can detect subtle skeletal changes and the extent of abscesses at an early stage, and is more valuable in areas where satisfactory images are not easily obtained by conventional radiography, such as the circumflex spine, cervicothoracic spine and irregularly shaped sacral spine. CT examination of spinal tuberculosis is most commonly fragmented, and spinal tumors often have similarities with it. Therefore, a comprehensive analysis should be performed in conjunction with clinical data, such as when there are foci of calcification or small bone fragments in the enlarged paravertebral shadow, which can help in the diagnosis of spinal tuberculosis. Despite this typing, CT is sometimes unable to differentiate spinal tuberculosis from spinal tumors.
(c) MRI examination has the characteristics of soft tissue with high resolution, and is better than CT for cranial and spinal cord examination, and can be scanned and imaged in the sagittal, axial and coronal planes of the spine. MRI of spinal tuberculosis shows the normal signal of the lesioned vertebrae, intervertebral discs and accessories compared with their normal counterparts in the spine, with those above being high signal and those below being low signal.
1, vertebral lesions: T1-weighted images show low signal at the lesion, or it is mixed with short T1 signal. T2-weighted images of vertebral lesions show signal enhancement. The images show that in addition to signal changes, the contours of vertebral body destruction, parallelogram changes after vertebral body collapse, and expanded paravertebral images are visible.
2, paravertebral abscess: paravertebral abscess of spinal tuberculosis shows low signal on T1-weighted images, while T2-weighted images show higher signal. The coronal plane can depict the outline and extent of paravertebral abscesses or bilateral lumbar major muscle abscesses.
3. Disc changes: Narrowing of the intervertebral disc on spinal tuberculosis radiographs is one of the early signs, and T1-weighted images on MRI show a low-signal narrowed disc. The normal nucleus pulposus has a transverse gap in the T2-weighted image, which disappears when there is inflammation, enabling early detection of disc inflammatory changes. MRI is more sensitive in the diagnosis of early spinal tuberculosis than any other imaging test, including ECT. In patients with clinical symptoms for 3-6 months and suspected internal spinal tuberculosis, MRI can show the affected vertebral body and paravertebral soft tissue (abscess) with low signal on T1-weighted images and high signal on T2-weighted images without abnormalities on radiographs.
Early MRI images of spinal tuberculosis can be divided into three types.
(1) inflammation of the vertebral body;
②Vertebral inflammation combined with abscess;
(iii) vertebral inflammation and abscess combined with intervertebral discitis.
It is worth proposing that the affected vertebrae in the inflammatory phase without soft tissue and disc signal changes cannot be distinguished from vertebral tumors, and should be confirmed by biopsy if necessary.
1, anti-tuberculosis drugs: an important position in the treatment of spinal tuberculosis The application of anti-tuberculosis drugs is a key measure in the treatment of spinal tuberculosis. Without effective anti-tuberculosis drug therapy, relying solely on surgical treatment is a very dangerous technique. Anti-tuberculosis drug therapy, local braking, and systemic supportive therapy are the most important and essential measures in the treatment of spinal tuberculosis. Surgical treatment alone for spinal tuberculosis without anti-TB is a very dangerous and frightening treatment and can only be administered under effective anti-TB conditions. Therefore, anti-tuberculosis medication occupies a very important place in the surgical treatment of spinal tuberculosis.
Currently, the commonly used first-line drugs include isoniazid (INH), rifampicin (REP), pyrazinamide (PZA), ethambutol (EMB), and streptomycin (SM), and second-line drugs include butylamine kanamycin (AK), kanamycin (KM), and cycloserine (CCFA). There are many combination drug regimens currently used in clinical practice. Many studies have shown that the combination of INH, RFP, and PZA can play their respective roles and synergistic effects, acting on 3 different metabolic flora and intra- and extracellular flora, and the drugs achieve bactericidal and sterilizing effects at different pH values, thus greatly reducing the treatment time.
At present, the more applied treatment plan is a short course of treatment based on the combination of streptozotocin, isoniazid and rifampicin, the course of treatment is generally 9-12 months, generally not more than 1.5 years. Some studies have shown that ultra-short-term chemotherapy of 4 to 6 months is not sufficient to determine the outcome. The safety of drug administration, tolerability must be taken into account. Blind pursuit of short-term dosing does not control the lesion. To date, many authors consider the conventional course of chemotherapy to be 18 months, the only drawback, the course is too long and can easily be missed or neglected. Pay attention to the observation of toxic and side effects during the drug administration, regular examination and timely adjustment of medication. Pay attention to the regular check of liver and kidney function to achieve the purpose of safe drug use.
V. Diagnosis
There is no difficulty in diagnosing typical cases based on medical history, symptoms, signs and imaging examinations. However, it is very difficult to diagnose early cases where no obvious abnormality is seen in X-ray radiographs. It is important to be familiar with the clinical symptoms and signs of the disease, to make a preliminary determination of the site of spinal involvement, and to perform imaging and laboratory tests. If necessary, puncture or even excisional pathological biopsy should be performed.
VI. Differential diagnosis
(a) Intervertebral disc degeneration: It is common in the cervical and lumbar spine, especially in manual workers around 40 years of age.
(B) congenital vertebral deformity: most commonly seen in 16 to 18 years old, low back pain, appearance or scoliosis and other deformities. hemivertebral body, vertebral body wedge-shaped changes or fusion of two adjacent vertebral bodies or at the same time visible deformities such as ribs, the number of transverse processes and ribs on both sides of the arch, such congenital deformities should be distinguished from healing vertebral tuberculosis.
(C) lumbar disc prolapse: mostly seen in men aged 20 to 40 years, with lumbar pain and sciatica, and pain aggravated by coughing. Examination shows lumbar scoliosis, reduced or absent physiological pronation, positive straight leg raising test on the affected side but the patient’s blood sedimentation and body temperature are normal. Lumbar spine 4-5 or lumbar spine 5 sacral 1 tuberculosis posterior lateral lesions are often confused with.
(iv) Ankylosing spondylitis: Mostly seen in young men, with significant morning stiffness in the lumbosacral region, positive for HLA-B27, without fever and other symptoms of tuberculosis intoxication. x-ray reveals destructive changes in the sacroiliac joint.
(e) Spinal septic inflammation: before the onset of the disease, the patient mostly has skin boils or other septic foci with sudden onset, high temperature, obvious toxic symptoms, pain in the affected part, limited movement, local soft tissue swelling and pressure pain. x-ray of the vertebral body can be seen bone destruction, narrowing of the intervertebral space, often with dead bone formation, mostly without abscess formation, the diagnosis should be confirmed by bacterial and histological examination.
(vi) spontaneous cricoaxial dislocation: often secondary to pharyngeal inflammation. children under 10 years of age, children often hold their jaws with their hands, have a sloping neck, limited neck movement, the cricoaxial vertebrae are dislocated forward on X-ray, the dentition is displaced laterally or posteriorly without bone destruction, and there is no shadow of a cold abscess. ct examination is helpful for diagnosis.
(vii) flat vertebrae: mostly seen in children, manifesting back pain, kyphosis, spinal motion restriction, no systemic symptoms, the disease commonly has two causes: vertebral body eosinophilic granuloma and osteochondrosis. x-ray radiographs of the affected vertebrae wedge-shaped changes, can remain a thin slice, while the adjacent vertebral space is normal, paravertebral visible slightly enlarged shadow, after the lesion is cured, the vertebral body height can be restored to varying degrees.
(H) Spinal tumor
It can be divided into two categories: primary and metastatic
1.Primary: common in patients under 30 years old, benign giant cell tumor of bone, osteochondroma, hemangioma, malignant lymphoma, chordoma, Ewing sarcoma, etc.
2.Metastatic cancer: Mostly seen in patients around 50 years old, common ones are lung cancer, breast cancer, kidney cancer, liver cancer, thyroid cancer, prostate cancer, etc., metastasizing to vertebrae or adnexa, while neuroblastoma is mostly seen in infants and children under 5 years old.
VII. Treatment
(a) Non-surgical treatment: Patients without indications for surgery for spinal tuberculosis should be treated with reasonable chemotherapy regimens and local braking. Patients with hypothermia and spinal back pain or biomechanical instability should rest on a hard bed. Glisson cloth belt traction or Halo-vest undershirt is indicated for patients with cervical instability. For abscesses on the body surface of the posterior pharyngeal wall of circumflex spinal tuberculosis with large abscesses affecting breathing or swallowing, puncture for pus aspiration is feasible.
Application of cranial ring-vest (Halo-Vest): Halo-Vest was used as a traction device for cervical spine disease causing cervical instability as early as the 1950s, and has greater superiority over other traction devices such as traction forceps or Minerve plaster undershirt and other traditional external fixation methods. After immobilization, the patient obtains a three-dimensional firm fixation. The patient can sit, stand and walk, thus shortening the time the patient is bedridden and avoiding other complications.
(b) Surgical treatment: According to the indications for surgery, lesion removal is performed electively after the symptoms of systemic tuberculosis poisoning are reduced. The route of surgery is selected according to the condition, objective conditions and the route with which the operator is familiar. The extrapleural approach is generally used for thoracic spinal tuberculosis. Those who are under 60 years of age, whose cardiopulmonary function is still acceptable, who have long paravertebral abscesses, 4 to 6 vertebral destruction, and many dead bones, and who want to prepare for prevertebral bone grafting; or who have paravertebral abscesses penetrating into the thoracic cavity or lungs can consider transthoracic lesion removal.
The principles of transperitoneal route for lumbar spine tuberculosis and removal of multisegmental (jumping type) tuberculosis lesions in the spine are as follows.
①priority treatment of lesions that may cause paraplegia;
②In case of similar severity of lesions in two segments, the upper segment should be treated first, followed by the lower segment;
③Treat the more severe one first, while the less severe one may be cured by non-surgical treatment;
④Cervical tuberculosis with good blood supply can be cured without surgery.
Spinal tuberculosis complicated by sinus tracts not cured by non-surgical treatment for 3-6 months can be treated surgically. After spinal tuberculosis surgery, bed rest is usually given for 6 to 8 weeks, and those who have reduced spinal pain, disappeared the original abscess, normalized body temperature, decreased blood sedimentation, and stabilized spinal structure can exercise to get up. First take care of their own chores, then gradually increase the amount of activity, and adhere to the full course of chemotherapy.
Eight, the indications and timing of surgical treatment: spinal tuberculosis does not always require surgical treatment, in which a considerable number of patients in the early stages, the lesion involvement is limited, bone destruction is slight, and no obvious cold abscesses appear, usually using anti-tuberculosis non-surgical treatment. The aim of surgical treatment is to remove the lesion; prevent or reduce pathological fractures and deformities of the spine; relieve the spinal cord and cauda equina nerve compression; and restore and reconstruct the physiological function of the spine.
The indications for surgery for spinal tuberculosis must be considered in a comprehensive manner, taking into account the patient’s general condition and the extent of the lesion, and must not be expanded arbitrarily.
(1) A clear site of tuberculosis lesion and cold abscess;
(2) Large dead bone or cavity in the lesion;
(3) Formation of sinus tracts that do not heal over time;
(4) The presence of neurological impairment and signs of spinal cord and cauda equina compression;
(5) Severe kyphotic deformity of the spine occurs in the diseased segment.
Poor systemic condition, significant anemia or hypoproteinemia, serious diseases of the heart, lungs, liver, kidneys and other important organs that cannot tolerate surgery; active tuberculosis lesions in other sites; resistance to anti-tuberculosis drugs and ineffective anti-tuberculosis treatment should be contraindications to surgery for spinal tuberculosis. In clinical practice, non-surgical treatment is recommended for some patients with mild disease, obvious effects of drug therapy, pediatric patients, and patients with poor general condition, important organ disorders and serious complications that may occur with surgery.
The timing of surgery for spinal tuberculosis is usually chosen before the cold abscess breaks down; before the tuberculosis bacterium becomes drug-resistant; before the spinal cord is compressed or before complete paraplegia. Surgery should be performed as early as possible once paraplegia has occurred. Under the control of anti-tuberculosis drugs, timely and complete removal of tuberculosis lesions can greatly shorten the course of treatment, prevent deformity or paraplegia, and significantly improve the cure rate of spinal tuberculosis. Spinal fusion can only maintain or re-establish spinal stability and prevent the occurrence or aggravation of kyphosis, but not correct spinal deformity.
To prevent the occurrence of delayed paraplegia, prevent thoracic deformity, avoid affecting cardiopulmonary function, and improve the degree of spinal deformity, spinal deformity correction is required. If the posterior convex deformity lesion has been stabilized. If the deformity is not obvious, correction may not be necessary. Spinal deformity correction surgery can be divided into posterior spinal deformity correction, anterior posterior deformity correction, and combined anterior and posterior approaches to correct posterior deformity. The anterior approach must be supported by an internal fixation, otherwise the bone graft may be pressed into the vertebral body or absorbed by the rebound force of the spine, resulting in orthopedic failure.