The assessment of thoracic pain

History 

A thorough and detailed history is vital in arriving at a differential diagnosis which in turn leads to appropriate examination and further investigations. The key points that should be covered in the patient with thoracic back pain are as follows.

Pain: the history of the patient's pain should be taken, with specific questions about its site, severity, nature, radiation, presence of rest or night pain, relieving or aggravating factors and the temporal history. Rest and night pain are themselves red flag symptoms and imply non-mechanical pain. The timing of the patient's pain gives a good indication of the seriousness of the underlying problems. A patient who has had thoracic back pain for 20 years is clearly less worrying than the patient with acute onset pain.

Injury: ask about preceding injury, no matter how trivial. A minor injury may be relevant in the patient with osteoporosis or ankylosing spondylitis. High energy trauma is more likely to lead to significant injury to the spine.

Associated features: ask about associated neurological features such as limb weakness and sensory changes. Often a good historian will be able to describe changes consistent with a dermatome or myotome. This will begin to identify the approximate location of the lesion and any neurological disturbance. Motor abnormalities may also lead to an alteration in the patient's gait. Ask about new walking aid usage. Changes in the patient's bowel or bladder control are considered a red flag symptom and imply significant cord compression and the potential need for urgent decompression surgery.

Past medical history: ask the patient about previous back disorders. Ask specifically about a previous diagnosis of malignancy. Enquire further about the primary, what treatment has been received and the prognosis if relevant. A history of previous surgery should be sought. Remember that abdominal structures such as the stomach, liver and pancreas refer pain to the thoracic region. Ask about a previous diagnosis of arthropathy. Ask about any prior investigations that have been carried out, their result and what treatment if any has been received so far (especially antibiotics and their duration).

Drug history: steroid or immunosuppressive medication is important, as are anticoagulants if you are considering the patient for surgery.

Family history: ask about inflammatory arthropathy, Scheuermann's kyphosis and ankylosing spondylitis.

Systematic review: a history of weight loss is very important. Also enquire about night sweats and fevers. Ask screening questions about the other body systems in the case of undiagnosed primary malignancy. Symptoms of any inflammatory condition such as early morning joint stiffness, eye symptoms, urethritis, dermatitis and gastroenteritis are relevant.

Examination 

Knowledge of the anatomy is essential to properly examine the thoracic spine. There are 12 thoracic vertebrae, the 1st, 11th and 12th are considered atypical. There are 12 pairs of costo-vertebral joints which are synovial plane joints between the ribs and vertebral bodies. There are ten pairs of costo-transverse joints, these being absent in the 11th and 12th levels. Each thoracic vertebra also articulates with the cephalic and caudal vertebra by means of the facet joints (zygapophyseal joints). The 1st articulates with the 7th cervical vertebra and the 12th with the 1st lumbar vertebra. The nerve roots exit immediately below the pedicle of the named thoracic vertebrae. The nerve roots at this level are relatively horizontal. This means that for thoracic disk prolapse there is no difference in the neural compression if the disk is far lateral.

General examination 

Start with a thorough examination of the whole patient looking for signs of generalized disease such as pyrexia, malaise, muscle wasting, nutritional status and signs of inflammatory arthritis. Gait should be assessed as compressive lesions of the thoracic spinal cord will cause myelopathy and associated gait changes. Look for walking aids.

Examination of the spine 

Inspection: the spine should be examined in its entirety systematically. Inspect for scars, sinuses and swellings. Look specifically for markers of neurofibromatosis and deformity in the coronal or sagittal plane. A gibbus (sharp angular kyphosis) is classically seen in tuberculosis of the spine (Pott's disease).

Palpation: palpate for any abnormal contour, warmth and tenderness. Whilst palpating the tender areas ascertain exactly from where the pain is originating. Is it diffuse or localized, superficial or deep? Can it be localized to the facet joints or to the paraspinal muscles? Are there any trigger points?

Percussion: this is useful in the spine to elicit deep tenderness suggestive of infection, trauma, tumour or inflammatory conditions. It is quite non-specific but may be indicative of structural disease.

Movement: both active and passive movement should be recorded. Normal costo-vertebral expansion is 3–7.5 cm. Chest expansion should be specifically tested as restriction is an early sign for ankylosing spondylitis. With the exception of Schober's test for examination of the lumbar spine flexion, it is very difficult to accurately quantify the range of motion. Finger floor distance is often measured in lateral bending and forward flexion. This is patient-specific and serves to provide documentary evidence of change in range of motion when following up a patient in clinic. Table 2 shows the normal range of motion of the thoracic spine.3

Table 2. Normal range of thoracic spine movement

	Movement	Normal range/degrees
	Forward flexion	20–45
	Extension	25–45
	Lateral flexion	20–40
	Rotation	35–50

Neurological examination 

Neurological examination should be thorough. There is a wide variation and cross over in the description of neurological myotomes and dermatomes in the text books. It is advisable to use the American Spinal Injuries Association neurological assessment chart (http://www.asia-spinalinjury.org/publications/2006_Classif_worksheet.pdf) to ensure that all findings can be documented immediately and accurately. Tone, co-ordination and proprioception should also be documented. Abdominal and lower limb reflexes should be examined and characterized. The plantar reflex is particularly important in assessing spinal cord function. Examination aids such an aesthesiometer, tuning forks and two point discriminators improve clinical accuracy. Assessment of anal tone, sensation and voluntary contraction is very important. Remember to get consent and have a chaperone if appropriate before examining patients.

Special tests 

The slump test (sitting dural stretch test) indicates impingement of the dura and spinal cord or nerve roots. The patient sits on the examining table and is asked to “slump” so that the spine flexes and the shoulders sag forward while the examiner holds the chin and head erect. Symptoms of sciatic pain or reproduction of the patient's symptoms indicates a positive test. If there are any symptoms in the cervical or lumbar spine these areas should also be examined.3

Blood tests 

The routine blood tests are a full blood profile, urea and electrolytes. Inflammatory markers such as ESR and CRP are very useful in detecting an infective or inflammatory condition. Blood cultures are mandatory in infections. Myeloma screening tests should be carried out in all cases of suspected tumour (plasma electrophoresis and urinary Bence-Jones protein). Rheumatoid factor and HLA-B27 are requested in suspected inflammatory spondylarthropathies. Liver function tests are useful for baseline measurement and monitoring treatment. Bone profile can pick up abnormalities of bone metabolism and give some clues to the underlying condition. Peripheral blood smears and bone marrow studies are useful in the diagnosis of haematological malignancies.

Plain radiographs 

These are often the first line radiological investigations carried out on patients. There is concern that they are not sensitive enough to exclude disease. They are however useful in advanced disease states and in the preoperative planning in some situations. It is important that they are of adequate quality with regard to the area of interest, adequate views and exposure.

Computed tomography (CT) 

This is a more sensitive investigation and gives good bone detail. The ability to reconstruct the images in the sagittal plane and coronal plane is very helpful. CT myelography is an alternative investigation in patients who have contra-indications to Magnetic Resonance Imaging (MRI). It however does not give good soft tissue detail especially of the spinal cord and hence may miss myelomalacia. It is useful in preoperative planning as the dimensions of various vertebral components can be accurately determined aiding implant placement. Three dimensional reconstruction can demonstrate bony destruction and deformity in very good detail.

Ultrasound 

This is of limited benefit in the thoracic spine due to the bony elements precluding ultrasound examination. It is however useful in assessment of paraspinal masses, collections and intraoperative localization of intra-dural spinal tumours. It is useful to assess intra-abdominal pathology.

Isotope bone scan 

This is a very useful modality due to its sensitivity and capability to screen the whole body. It plays an important role in staging disease and detecting multifocal disease in the skeleton in inflammatory, traumatic, neoplastic and infective pathology. Labelling of leucocytes can localize infections more precisely and differentiates them from other causes of increased uptake.

MRI 

This modality has revolutionized the investigation and management of several conditions of the thoracic spinal column. There is some concern that it is too sensitive thus giving rise to false positive findings. In most instances it can reliably distinguish between infection, fracture and tumour. It has also been recently used in distinguishing between old and new fractures or fracture non-unions in the thoracic spine with the STIR (Short Tau Inversion Recovery) sequence enabling effective use of cement augmentation. It gives good detail of the spinal cord thus showing up myelomalacia which is seen in chronic compressive lesions. Wood et al. carried out an MRI study in 90 patients with no thoracic pain. 60 of these patients had no thoracic or lumbar pain, 30 had low back pain only. 73% of the patients had positive anatomical findings at one or more levels of the thoracic spine including herniation of the disc in 37%, bulging of a disc in 53%, annular tear in 58%, deformation of the spinal cord in 29% and Scheuermann-type end-plate changes or kyphosis in 38%.4

It is important that the history, clinical examination and imaging findings are correlated in coming to a diagnosis.

Benign thoracic pain 

This is diagnosis by exclusion and can only be made after thorough investigation. It is a reasonably well defined entity and appears more commonly in females in the third decade and is believed to be due to poor posture. It is usually managed by postural advice and physical therapy. Dreyfuss et al. performed a study on nine asymptomatic volunteers demonstrating that intrarticular injection into the thoracic zygapophyseal (facet) joints can cause both local and referred pain.5 Keating et al. showed that thoracic tenderness is not a normal finding in asymptomatic subjects.6 Stolker et al. have reported on the result of facet denervation in chronic thoracic spinal pain in 40 patients. Patients had pain of more than 12 months duration with failed conservative treatment. A diagnosis of thoracic facet syndrome was made based on clinical criteria and a positive response to a prognostic blockade of the medial branch of the dorsal ramus of the thoracic spinal nerve. The treatment was by percutaneous radiofrequency denervation of the facet joints. At follow-up of 18–54 months 44% were pain free and 39% had more than 50% pain relief.7

Deformity 

Scheuermann’s kyphosis may be a cause of pain. There are two types. Type 1 is thoracic and produces more deformity than pain. Type 2 (apprentice's spine) is thoracolumbar and produces more pain than deformity. Idiopathic scoliosis is generally a painless condition. There is a wide variation in symptoms reported in the literature. Murray et al.8 reported on the natural history and long term follow-up of Scheuermann’s kyphosis. The patients who had Scheuermann’s kyphosis had more intense back pain, jobs that tended to have lower requirement for activity, less range of motion of extension of the trunk and less strong extension of the trunk and differential localization of the pain. No significant differences between the patients and the control subjects were demonstrated for level of education, number of days absent from work because of back pain, extent that the pain interfered with activities of daily living, presence of numbness in the lower extremities, self-consciousness, self-esteem, social limitations, use of medication for back pain or level of recreational activities. Also the patients reported little preoccupation with their physical appearance. Normal or above normal pulmonary function was found in patients in whom the kyphosis was less than 100°. Patients in whom the kyphosis was more than 100° and the apex of the curve was in the first to eighth thoracic segments had restrictive lung disease. Five patients had an unexplained mildly abnormal neurological examination. Mild scoliosis was common and spondylolisthesis was not observed. They concluded that although patients who have Scheuermann’s kyphosis may indeed have some functional limitations, they do not have major interference with their lives. Their patients who did not have an operation for the kyphosis, adapted reasonably well to this condition. They recommended that the use of operative treatment for Scheuermann kyphosis should be carefully reviewed.

The prevalence of back pain in children who have idiopathic scoliosis has been reported by Ramirez et al.9 in a study of 2442 patients. 23% of their patients had back pain at the time of presentation and an additional 9% had back pain during the period of observation. There was a significant association between back pain and an age of more than 15 years, skeletal maturity, post-menarchal status and a history of injury. There was no association with gender, family history of scoliosis, limb length discrepancy, magnitude or type of curve or spinal alignment. 9% of the patients who initially presented with back pain had an underlying pathological condition. They concluded that “when a patient with scoliosis has back pain, a careful history should be recorded, a thorough physical examination should be performed and good quality plain radiographs should be made. If this initial examination reveals normal findings, a diagnosis of idiopathic scoliosis can be made, the scoliosis can be treated appropriately and non-operative treatment can be initiated for the back pain. It is not necessary to perform extensive diagnostic studies to evaluate every patient who has scoliosis and back pain”.9 It has to kept in mind that infections and tumours of the spine may present with deformity which may or may not be painful.

Infections 

Discitis with vertebral osteomyelitis (DVO) can present insidiously with low grade thoracic pain and pyrexia though this is not a constant feature. The classic triad of pain, temperature and local tenderness may be seen. There may be a history indicating immunocompromise. Evidence of vertebral osteomyelitis has been found in prehistoric man as far back as 7000BC. Hippocrates was the first to describe this infection of the vertebral column, subsequently Galen related this infectious process to the development of spinal deformity. Servino and Pott later characterized and described the pathology of tuberculosis infection of the spine. In 1879 Lanelonge described bacterial osteomyelitis as we recognize it today.10

Pyogenic spinal infection encompasses septic discitis, vertebral osteomyelitis and epidural abscess.10 Paraspinal abscesses could also result from spinal infection with spread anteriorly and or posteriorly. Although surgery is rarely required unlike with tuberculosis infection.

Approximately 95% of pyogenic vertebral osteomyelitis involves the anterior elements with only 5% involving the posterior elements of the spine. This is due to the voluminous blood supply to the vertebral body in conjunction with its rich cellular marrow. Predisposing factors for spinal infection include advancing age, malnutrition, immunocompromise, intravenous drug abuse, Human Immunodeficiency Virus infection, malignancy, chronic steroid usage, renal failure, septicaemia, recent spinal surgery and intravascular devices.10 Tuberculous spine infection is rising in incidence and may be preceded by pulmonary infection. Tuberculosis in general seems to be increasing in incidence despite the introduction of effective chemotherapy.11 Tuberculosis of the spine or Pott's disease occurs in less than 1% of patients with tuberculosis. Concurrent infection of the spine with mycobacterium and pyogenic bacteria has been reported but is not common.11 There may be localized tenderness and deformity which is usually a localized angular kyphosis (gibbus). Neurological deficit may be present initially or develop during treatment and has to be looked for. It may vary from meningitis, nerve root compression with radiculopathy, lower extremity weakness and paraplegia. Presentation with neurological deficit warrants surgery for decompression and stabilization. The prognosis for neurological recovery is much better than with tumour.

Pyogenic discitis if detected early responds well to isolation of the causative organism and appropriate antibiotic therapy.10 A short course of empirical antibiotic therapy may lead to negative culture on blood and biopsy making management difficult. An uncomplicated course may result in bony ankylosis across the infected level.9 Late presentation is usually with destruction of the vertebral end-plate and adjacent bodies resulting in instability and/or neurological compromise due to deformity or epidural abscess.12 This may require surgery for decompression for the neural elements and restoring stability with instrumentation of the affected segments. Haematogenous Meticillin Resistant Staphylococcus Aureus (MRSA) spondylodiscitis (DVO) has been reported in 13 patients by Al-Nammari et al.13 All their patients presented with back pain, spinal tenderness and systemic upset. The thoracic spine was most commonly affected (53%) compared to lumbar (33%), thoracolumbar junction (7%) and the cervical spine (7%). They had a mortality of 38%, neurological deficit was present in 50% of survivors and at 1 year 29% of survivors had MRSA bacteraemia and recurrence of spondylodiscitis. Biopsy and cultures are important because occasionally the spinal infection may be caused by unusual organisms and may not respond to conventional treatment. Biopsy for presumed infection has occasionally proved to be tumour.14 Non-operative treatment consists of prolonged courses of intravenous antibiotics guided by sensitivities if available. The current recommendation is for 6 weeks of intravenous antibiotics.15 In advanced disease states with paraspinal and or epidural abscess surgical debridement and evacuation of the abscess followed by instrumented fusion and long term intravenous antibiotics will give the best results. Paraspinal abscesses without spine instability may be treated by percutaneous image-guided drainage.

Childhood spinal infection is extremely rare. A true infective discitis is possible in children due to the persistence of blood supply to the intervertebral disc. However childhood discitis presents a non-uniform picture with non-specific and usually mild symptoms, making it difficult to diagnose. It is more often non-infectious. Kayser et al.16 have described their series of 25 children treated non-operatively with long term follow-up. Ten of their patients had thoracic spine involvement. On average their patients had a delay in diagnosis of 14 weeks. This emphasizes the need for a high index of suspicion in children presenting with non-specific symptoms. Figure 2 demonstrates the appearance of DVO with destructive changes.

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Figure 2 MRI of discitis with vertebral osteomyelitis.

Tumours 

The thoracic spine is affected by both primary and metastatic tumours. Primary tumours may be benign or malignant. The benign primary tumours may be osteogenic such as osteoid osteoma and osteoblastoma which are more common in the posterior elements or arise from haematological tissue present in the vertebral column such as haemangioma, Langerhans cell histiocytosis. Non-ossifying fibromas may arise from the connective tissue elements. Malignant primary tumours such as osteogenic sarcoma, Ewing's sarcoma, chondrosarcoma and multiple myeloma may occur.12 Rare tumours such as haemangiosarcomas and malignant haemangiopericytomas are also occasionally seen. Intra-dural tumours of the spinal cord and the meninges should also be kept in mind.

Metastatic tumours are the commonest form of malignant tumour affecting the spine. The published series by Tokuhashi et al.17 demonstrated that thoracic spine metastases were the commonest region for all spinal metastatic tumours (cervical 46, thoracic 111, lumbar and sacral 59 out of 183 patients). The primary site may be in the breast, lung, intestine, kidneys or prostate. Gastro-intestinal tumours are unusual but rising in incidence. Table 3 shows the location of the primary tumour in Tokuhashi's series of 183 patients with spinal metastasis.17

Table 3. Location of primary in Tokuhashi's series

	Location of primary tumour site	Number of patients	Percentage
	Lung	46	25.1
	Kidney	22	12.0
	Prostate	20	10.9
	Breast	14	7.7
	Liver	13	7.1
	Stomach	6	3.3
	Rectum	6	3.3
	Colon	5	2.7
	Pancreas	5	2.7
	Thyroid	4	2.2
	Ovary	4	2.2
	Oesophagus	3	1.6
	Bladder	3	1.6
	Other	16	8.7

The National Institute of Clinical Excellence (NICE) has issued guidelines on the diagnosis and management of suspected metastatic spinal lesions and spinal cord compression (http://www.nice.org.uk/nicemedia/pdf/CGFullGuideline.pdf). The guidelines state that patients with a known malignant tumour complaining of back pain should be considered to have metastatic spinal disease until proved otherwise. These patients should have access to a liaison nurse who should assess patients and refer for MRI scanning and subsequently arrange a spinal surgery consultation. They recommend that a liaison nurse, MRI scanning and spinal surgery should be available round the clock. These Regional Centres guidelines are very comprehensive, unfortunately the infrastructure required to comply fully is still not available in all centres. Some patients present with spinal involvement without a previous diagnosis of tumours elsewhere. The principles of management of spinal tumours are no different from bone tumours elsewhere. The priority is to confirm the diagnosis and grade with biopsy, stage the disease and carry out definitive management. Various scoring systems are available to guide the management of metastatic spinal tumours such as the Tokuhashi prognostic scoring system. The Tokuhashi system of scoring gives points for various attributes of the patient and the type of tumour, which guides in decision-making regarding non-operative treatment, palliative surgery or tumour excision.

They have shown good correlation with real and predicted outcome. Table 4 summarizes the indications for either non-operative or operative management in their series.

Table 4.

	Indications for non-operative management	Indications for operative management
	High sensitivity to hormone therapy or radiotherapy with less than 6 months life expectancy	Pain and/or paralysis due to collapse of the spine
	Poor general condition	Pain and paralysis due to tumour invasion of the spinal cord
	Patient does not demonstrate will to live	Radio resistant cancers
	Did not consent to surgery

The management of primary malignant tumours is complex due to the presence of the neural elements. Radical curative excision of a primary tumour or isolated metastasis involves complete excision of the involved vertebra (spondylectomy). This often requires a combined anterior and posterior surgery with risk of neurological deficit and other systemic complications. Tumour-like lesions are rare. Sarcoidosis of the thoracic spine occurring in the vertebral body and extending posteriorly has been reported in the literature.18 Sarcoidosis has also been reported to occur as an intra-dural extra-medullary mass.19 Figure 3 demonstrates the MRI appearance of a metastatic spine lesion with spinal cord compression and post-operative radiographs after decompression and fixation.

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Figure 3 MRI of metastatic spinal tumour.

Fractures 

High velocity injuries are easy to diagnose based on the history and clear clinical symptoms and signs. High velocity unstable fractures are generally managed with internal fixation which may be posterior alone or combined anterior and posterior. Fusion across the unstable segments is carried out when there is significant soft tissue injury that will not be stable after bony union. Figure 4 shows a CT reconstruction of a high velocity thoracic spine fracture.

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Figure 4 Chance fracture of thoracic spine (CT).

Osteoporotic vertebral compression fractures however may present as thoracic back pain with no clear history of trauma and may present with an acute or insidious onset of pain. These patients may be elderly and confused. Younger patients at high risk of osteoporosis should also be assessed with this possibility in mind. Early diagnosis and appropriate management may avoid prolonged pain and loss of sagittal balance.20

Osteoporotic fracture treatment has undergone a revolution since the advent of cement augmentation. Fractures that do not become pain free in a designated period of time can be augmented with bone cement (Poly Methyl Methacrylate) giving immediate stability and pain relief. There is still heated debate on the relative merits of vertebroplasty vs. kyphoplasty. Vertebroplasty is believed to be cheaper and needs less operative time but does not significantly restore vertebral height. Kyphoplasty is more expensive and time consuming but restores vertebral height to some extent and is also believed to reduce the risk of cement extravasations.20 Cement augmented restoration of vertebral height ideally with a bioactive cement combined with instrumented fixation is also done in some centres with the aim of achieving and maintaining improved sagittal alignment. The main concern with cement augmentation is the reported occurrence of cement leaks which may be epidural (occasionally needing surgical evacuation), into the disc, into the root foramen and the para-vertebral veins. Embolization of cement and marrow to the lungs is also an area of concern leading some authors to suggest that no more than three levels should be treated at any one time.

Degenerative conditions 

Degenerative disc disease is unusual in the thoracic spine. The lower thoracic spine is more prone to develop this condition. The thoracic spine has a physiological kyphosis and the canal is also relatively narrow and therefore any prolapse of the thoracic intervertebral disc has the potential to cause spinal cord compression. The literature appears to suggest that most patients with a thoracic intervertebral disc prolapse are asymptomatic,4 however there are several papers documenting the catastrophic effects of thoracic intervertebral disc prolapse.21, 22 In this situation prompt diagnosis and decompression are required for a full neurological recovery. The gloom which surrounded the condition of thoracic disc protrusion has lightened, and in part with improved diagnostic facility, in part with the development of new surgical techniques. The earliest record of a patient treated by operation was that of Adson in 1922 at the Mayo clinic, reported by Love and Schorn in 1965.22

The surgical treatment of the prolapsed symptomatic intervertebral disc has undergone significant evolution. Early surgeons attempted to remove them posteriorly through a laminectomy and decompression but this was associated with a high incidence of failure to recover and some deterioration in neurology.22 Newer techniques have approached the spine from the front or laterally. More recently video-assisted thoracic decompression is gaining favour in areas where this is available.23 Benson and Byrnes described a series of 22 patients22 of whom only 11 patients complained of back pain and this was poorly localized. The back pain when present was typically not severe and was relieved by rest, it invariably preceded the signs of cord compression. Leg pain was common but followed no specific pattern, most frequently aching pain was felt at one or both knees. Pain at the hip, ankle or foot was also mentioned. The quality of the pain was also variable. It was sometimes constant, cramping or spasmodic. It could be dull, burning or lancinating. One third of patients experienced girdle pain. Most patients complained of sensory symptoms other than pain. These were usually of numbness or coldness in the legs. Patients rarely complained of paresthesiae. All but one patient complained of weakness or heaviness in the legs. Bilateral weakness was twice as common as unilateral weakness. Weakness was progressive in every patient. Examination showed that power was impaired in all but two patients. Weakness of the lower abdominal muscles, well demonstrated when the umbilicus is seen to rise as the patient attempts to sit upright, was a frequent observation. Most patients had increased lower limb muscle tone. Lower abdominal reflexes were absent, knee and ankle responses were exaggerated and the plantar responses were extensor. Symptomatic patients with neurological involvement should have surgical decompression to improve the prognosis. Figure 5 shows MRI images of a patient with significant spinal cord compression from a prolapsed thoracic intervertebral disc.

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Figure 5 Prolapse of thoracic intervertebral disc.

The management of prolapsed thoracic intervertebral disc in our institution is based on the location of the prolapse. The trans-thoracic route is used in predominantly central prolapses.24 Figure 6 demonstrates the trans-thoracic approach before and after excision of the prolapsed disc.

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Figure 6 Trans-thoracic decompression of intervertebral disc prolapse.

Ossification of the posterior longitudinal ligament (OPLL): This can present as vague pains and usually comes to medical attention with neurological impairment with a change in gait and progressive neurological deficit. It is a very rare condition and is more often seen in countries of the far east. Adequate decompression is necessary for improvement in neurology deficit. As the compression is predominantly anterior it is best approached anteriorly. In Japan OPLL has been officially recognized as a difficult disease by the Public Health Bureau of the Ministry of Health and Welfare of the Japanese government. Hanai et al.25 have described anterior decompression in 12 patients with thoracic OPLL good results were seen in patients with complete removal of the ossification. Both Hanai et al. and Yamazaki et al. have reported that laminectomy alone is not effective in this condition.25, 26

Spondylarthropathies 

The spondylarthropathies have been defined as the presence of inflammatory spinal pain or synovitis and one or more of the following.27

The most common of this group of diseases is ankylosing spondylitis (AS). It affects approximately 1 in 200 adults with a variable prevalence. Symptoms usually start in the low back and with time ascend to the thoracic spine. It is associated with morning stiffness and restriction of chest expansion due to involvement of the costo-vertebral joints. Patients develop acute iritis at some stage in the disease process. Bones become osteoporotic and patients with AS are five times more likely to get fractures than the general population. These fractures may be overlooked or attributed to exacerbation of the AS. These fractures are prone to pseudarthrosis and may cause neurological deficit if unstable. Immobilization of these patients on a rigid spinal board may also cause neurological deficit if their usual spine shape is not respected. Inflammation of the disc (aseptic) may occur more commonly in the mid-thoracic spine and is usually asymptomatic and noticed as an incidental finding on imaging.

Other associated conditions are