Degenerative
diseaes of the spine
Pain due to degenerative disease of the cervical and lumbar spine is
very common in the general population. A wide variety of terms is used
describing this, including lumbago, wear and tear, spondylosis and a slipped
disc. What is clear is that parts of the spine are subject to a series of
changes in both the intervertebral disc and the adjacent vertebrae. They are
associated with local pain and may be associated with the compression of the
spinal cord or nerve root. It is also apparent that these changes occur with
age. MRI scanning has provided excellent evidence of this disc degeneration,
with loss of water content, these changing often without associated pain (see
Fig. 33.15). Thinning of the annulus and the appearance of radial slits
allow the nucleus to bulge —and may eventually rupture through causing disc
prolapse.
Neurological
involvement can therefore occur due to cord, cauda equina or toot compression by
soft disc, ligamentous hypertrophy or osteophyte formation.
Cervical
degenerative disease
Two patterns emerge.
The
symptoms are usually slowly progressive with, on examination, signs of an upper
motor neuron lesion with a glove and stocking distribution sensory loss. The
neck pain may not be a major feature. Examination will usually reveal a
restricted range of cervical spine movement (see Fig.
33.17).
Commonly
seen in the midcervical region, signs of radiculopathy at the affected level
may be superimposed. Presence of the deltoid jerk suggests compression above the
C4/5 level.
Investigation
Following a careful history and examination to define the pattern of
neurological compromise and the clinically
Plain
X-rays provide details of the bony architecture and evidence of osteophyte
formation. Instability can be seen and measured (see Fig.
33.18). MRI in
sagittal and axial views allows detailed study of the spinal cord — including
changes within the cord itself — together with views of the exiting nerve
roots and root canals. MRI does not provide ‘dynamic’ information about the
cervical spine and should be used in conjunction with plain X-rays in flexion
and extension (see Fig. 33.19).
For cervical radiculopathy the diagnosis is usually apparent. The
differential includes cervical rib, producing a T1 syndrome, ulnar or median
nerve entrapment syndromes, metastatic disease in the cervical spine, or even
direct brachial plexus involvement via an apical lung tumour (Pancoast
syndrome).
For
patients with a myelopathy, clearly other causes of spinal cord compromise
rarely occur, but should be considered. These include an intraspinal tumour,
infection or instability associated with conditions such as rheumatoid
arthritis. Beware the tumour at the level of the foramen magnum leading to
wasting of the small hand muscles.
Management
Radiculopathy. In over 75 per cent of patients the
symptoms will resolve with conservative measures, including rest, analgesia,
the use of a cervical collar and physiotherapy by an experienced therapist.
Physical therapies are becoming increasingly specialised and appropriately timed
treatments will usually produce good results.
Care
should be taken with cervical collars. A short-term support can become a
long-term crutch. Their length of use should be avoided.
Surgery
is indicated according to the duration and severity of the pain, physical signs,
the radiological appearances and
To
effect decompression of the nerve root, either an anterior cervical discectomy
approach can be used, or posterior foraminotomy. For soft disc prolapse causing
nerve root compression, an anterior approach is most frequently used.
Myelopathy.
There is much debate about how and when to proceed to surgery. The aim of the
operation is to prevent further deterioration. If there is improvement,
then this is to some extent a bonus and it is important that the patient and
their family are advised of this. Despite decompression, in 30 per cent of
patients there will be further deterioration, probably due to vascular changes
within the cord itself.
Surgical
decompression is, therefore, appropriate for those who are deteriorating, whose
symptoms interfere
The
aim is to decompress the spinal cord and maintain or establish stability. This
can be done by an anterior or a posterior approach to the spine. Anterior
approach requires removal of soft disc, osteophytes and hypertrophied ligaments,
often over multiple levels. Fusion, intervertebral grafts or onlay plates can
then be achieved.
A
posterior cervical laminectomy provides easy access to decompress the spine over
multiple levels and great care must be taken to avoid spinal cord injury. The
decision between anterior and posterior approaches depends again on the
pathology, the presence of instability and the experience of the surgeon.
The
advantages and disadvantages of the two approaches are considered in Table
33.3.
Inflammatory
disorders involving the cervical spine
Rheumatoid
arthritis
This commonly affects the spine and particularly the cervical spine. Patients often present with stiffness and pain in the neck, and some patients present with neurological symptoms due to compressive myelopathy in the neck. Diseases in the joints in turn lead to soft-tissue destruction and then instability.
The three common abnormalities are:
• atlantoaxial subluxation;
• proximal migration of the odontoid with basilar impression;
• lower cervical spine subluxations.
Ankylosing
spondylitis
This is relatively uncommon, but can present with painful stiffness of
the spine. It is more common in males, most of whom will be human leucocyte
antigen (HLA) B27 positive. Other inflammatory markers will be raised. In
general physiotherapy combined with anti-inflammatory drugs will control
symptoms adequately. However, severe deformities will occasionally be seen and
these may require major surgery to the spine to effect correction. Occasionally
patients with ankylosing spondylitis will present after minor trauma with
unstable fractures. These patients should be assumed to have an unstable injury
until this has been excluded. Surgical stabilisation leads to satisfactory
results in most cases.
Thoracic
spinal degenerative disease
This is rare. Thoracic disc is the commonest form of degenerative
thoracic disease that requires surgery.
Presentation
More common in males (5:3 ratio) and usually in the lower
thoracic spine, the patients may present with a history of injury but this
usually occurs spontaneously.
Pain
may not be a major feature. The symptoms will progress very rapidly over a few
days, or may occur insidiously over years. The presenting features are those of
progressive spinal cord compression with, initially, often dissociating signs,
but if undiagnosed will finally progress to a paraplegia with a sensory level,
to loss of sphincter function.
Investigation
Plain X-ray may reveal calcification in the disc at the affected level,
with calcification of the protruding disc visible.
CT
scan. As part of a CT myelogram, this will confirm the epidural compression at
the level of the disc prolapse.
MRI
scan remains the investigation of choice. Be aware of the level of the disease
and whether it is lateral or central (see Fig. 33.21a and b).
Management
Removal of a thoracic disc represents a very different operation to
that of cervical or lumbar disc. The prolapse can be hard and calcified or
occasionally soft and liquid, appearing like pus. The dura may even be eroded.
A
standard laminectomy is dangerous and a lateral or anterior transthoracic
approach is required to excise these lesions.
If
truly central, a transthoracic route, with drilling out of the vertebral body
above and below the level of the disc prolapse, will allow piecemeal removal of
the disc and decompression of the spine.
For
the laterally placed discs a costotransversectomy with division of the
paravertebral muscles and excision of the rib head provides good access, again
drilling away the vertebral bodies above and below the disc to allow its
removal. Check the levels very carefully by preoperative and/or peroperative
imaging and warn the patient, especially about the risks of paralysis due to
surgery.
Lumbar
spine
Degenerative disease of the lumbar spine is almost universal with
increasing age. The disc ages owing to deterioration of the proteoglycan within
the disc, which becomes dehydrated as a result. Therefore the disc becomes
narrower and this in turn narrows the nerve root canals where the lumbar nerve
roots exit from the spinal canal. Secondary changes also occur in the facet
joints with loss of joint space, sclerosis and osteophyte formation.
Between 70 and 90 per cent of individuals will
experience back pain at some point in their lives. The commonest site of pain in
the spine is the intervertebral disc. Although the central part of the disc has
no nerve supply, the annulus is very sensitive and is often a source of pain.
Degeneration tears often occur in the annulus and these can be a source of pain.
Neurological
symptoms can also occur as a result of degenerative disease in the spine.
Tears of the annulus can allow part of the nucleus pulposus to herniate through
the annulus. The weakest part of the annulus is the postero-lateral corner, and
as a result the nerve root is often compressed in the
Another
effect of degeneration is that spinal stenosis can occur due to a combination of
narrowing of the disc, osteophyte formation from the joints and thickening of
the ligamentum flavum. The stenosis can either be central, lateral around the
exiting nerve roots or a combination of the two. Most patients with spinal
stenosis are elderly but some patients present young, and the majority of these
has developmental spinal stenosis where the spinal canal is narrow from birth.
Presenting
symptoms
Back pain is usually felt in the lumbar area and may radiate to the
buttocks and the back of the thighs. If the pain is coming from the upper lumbar
region, it may radiate to the front of the thigh. Pure back pain very seldom
radiates below the knees. Patients will often complain of spinal stiffness and
of difficulty in the activities of daily living such as picking things up,
shopping, sitting, walking, running and so on. Back pain can occur in any age
group, but beware of the child with back pain because it is likely that there is
some more serious underlying condition (see above). Other features of back pain
which are worrying include night pain which prevents sleep or unremitting pain
which cannot be controlled with pain relief. Spinal tumour or spinal infection
must be excluded in these patients.
Disc
prolapse
Disc prolapse occurs most commonly in middle age although it can occur
in adolescence and in the elderly. The typical history is of an episode of back
pain either related to lifting and/or twisting or which occurs spontaneously.
Eighty per cent of disc prolapses occur in the lumbar spine, the majority at
L5/S1 (see Fig. 33.22) and at L4/L5. The back pain commonly lasts for 2—6
weeks and may continue for longer. The back pain will often improve then but is
followed almost immediately by sciatica or nerve root pain. The pain will
usually follow one or more dermatomes, and is often associated with neurological symptoms, altered sensation and weakness in the
muscles innervated by the compressed nerve roots. Serious neurological symptoms
may he an indication for urgent surgery to decompress the nerve roots, but in
general a period of waiting is best because 90 per cent of patients will have
relief of their pain within 6 weeks. Minor degrees of weakness and numbness will
usually improve with time and may resolve completely. Motor weakness is more
likely to recover than sensory change.
Spinal
stenosis
Spinal stenosis presents typically in the elderly patient and tends to
develop gradually (Fig. 33.23). The patient may develop back pain, especially
standing and walking, which is associated with neurological symptoms in the
legs. Patients report pain, weakness and numbness in the legs on standing or
walking, and their walking distance is usually limited. They may complain that
their legs go rubbery or tend to give way. Their symptoms usually resolve with
rest, especially sitting down for 5—10 minutes, and then they can continue.
They often report fewer symptoms going up hill or walking using a rollator or a
shopping trolley. The reason for this is that the spinal canal is made wider
with spinal fiexion. This helps to differentiate these patients from those with
vascular claudication who find it worse uphill. Usually the symptoms of vascular
claudication will be relieved more rapidly.
Treatment
The majority of patients with back pain can be treated with
physical treatments such as physiotherapy, chiropractic, or the various other
treatments available. Explaining to the patient that they have a nonprogressive
condition which is very common will help them to cope with the symptoms.
Medications such as analgaesics and anti-inflammatories can also be used.
Adjustments to work situations (e.g. seating) and to day-to-day life (e.g. less
driving, more physical
Disc
prolapse
Disc prolapse usually resolves within 6 weeks, and simple pain relief
may be all that is required in these patients. Longitudinal studies have
demonstrated that most of these disc prolapses will resolve with time.
Patients with evidence of cauda equina compression must be managed as an emergency.
Symptoms
suggestive of this are:
• very restricted straight leg raising bilaterally;
• numbness in the perineum;
• inability to void or difficulty voiding urine;
• inability to have or difficulty in having bowels open;
• lax anal sphincter;
• severe pain.
In
the patient with simple sciatica various options are available.
• Epidural steroid injection — about 30 per cent success rate, low
complication rate, day-case procedure.
• Chemonucleolysis (injection of chymopapain into the disc
itself) — about 70 per cent success rate, day case or overnight stay. Often
causes back pain in the early stages. May take some weeks to be effective. Low
complication rate, occasional anaphylactic reaction to the chymopapain.
• Laser discectomy (laser coagulation of the disc) — success
rate 50—70 per cent, less back pain than chemonucleolysis, day-case procedure,
low complication rate.
• Microdiscectomy — success rate 80—90 per cent. Three
per cent long-term complication rate (e.g. nerve damage, infection, long-term
back pain). Requires hospital admission for a few days. Longer convalescence.
• Standard discectomy — as for microdiscectomy, but longer
scar, longer in hospital, longer recovery.
There
is no reason in most cases why closed techniques cannot be used initially and
then open surgery used if other methods fail. In older individuals associated
spinal stenosis is common and open techniques are more likely to be effective.
Many
patients with spinal stenosis are elderly, and nonsurgical methods of
treatment may be better for some. Various treatments have been used with fairly
low success rates such as lumbar corset, epidural injection of steroids and
traction. Physiotherapy with flexion exercises can be helpful in a minority of
patients. Calcitonin has been used with some success for treating spinal
stenosis, particularly in the elderly who may not be fit for surgery.
One-hundred international units of calcitonin are given by intramuscular (i.m.)
injection 4 days a week for 4 weeks. Success rates of 20—3 0 per cent have
been reported, but to date there has not been a randomised trial to assess the
treatment.
Surgery
is effective in about 70 per cent of patients with spinal stenosis.
Decompression of symptomatic nerve roots and central stenosis can give very
effective relief.
Spondylolisthesis
Spondylolisthesis is a common condition and is usually caused either by
spondylolysis or by degenerative change (Fig. 33.24). Spondylolysis is a defect
in the bone in the pars
Degenerative
spondylolithesis is common in the elderly and occurs owing to degeneration of
the disc and the associated facet joints. It can be associated with spinal
stenosis, and if decompressive surgery is contemplated, it is usually best to
carry out an un-instrumented fusion to prevent progression of the slip.