Kyphosis is curvature of the spine that causes the top of the back to appear more rounded than normal.
Everyone has some degree of curvature in their spine. However, a curve of more than 45 degrees is considered excessive.
Sometimes kyphosis doesn't cause any symptoms other than the back appearing abnormally curved or hunched. However, in some cases the condition causes:
- back pain and stiffness
- tenderness of the spine
Back pain can be particularly problematic in adults with kyphosis because the body has to compensate for the spinal abnormality.
If you have severe kyphosis, your symptoms may get worse over time. You may also have difficulty breathing and eating.
What causes kyphosis?
In kyphosis, the normal curve in the middle section of vertebral column (the thoracic vertebrae) is more curved than normal. There are a number of reasons why this might happen, including:
- poor posture (postural kyphosis) - slouching, leaning back in chairs and carrying heavy bags can stretch supporting muscles and ligaments, which can increase spinal curvature
- abnormally shaped vertebrae (Scheuermann's kyphosis) - if the vertebrae don't develop properly, they can end up being out of position
- abnormal development of the spine in the womb (congenital kyphosis) - if something disrupts the spine's normal development, two or more vertebrae sometimes fuse together
- age - as people get older, their spinal curvature can be expected to increase
Kyphosis can also develop as a result of a spinal injury.
Read more about the causes of kyphosis.
If you have kyphosis, your treatment depends on how curved your spine is, whether you have any additional symptoms such as back pain, and the underlying causes.
Children with kyphosis may be able to be treated using non-surgical methods, such as bracing, to limit the progression of kyphosis as they grow. Treatment for mild kyphosis may not be necessary.
Kyphosis rarely requires surgical treatment. It's only needed in some severe cases to correct the curvature of the spine.
Read more about treating kyphosis.
Older children with kyphosis may become concerned or embarrassed about the effect the condition has on their appearance, or having to wear a back brace.
These concerns can affect different children in different ways. Some children can become socially withdrawn and they may be reluctant to take part in activities, such as PE, where their condition may be exposed.
There are no easy answers to these problems, but it can sometimes help to reassure your child that their feelings will improve with time.
Complications of kyphosis usually only occur in more severe cases. They include:
- persistent pain that can't be controlled with medication
- breathing difficulties caused by the spine compressing the lungs and airways
Occasionally, people with kyphosis can have difficulties when the nerves running through the spine become compressed or pinched. This can disrupt nerve signals and cause symptoms such as:
- numbness or weakness in the arms and legs
- problems with sense of balance
- loss of normal bladder or bowel control
These serious complications require urgent medical attention and surgery would usually be recommended.
Can kyphosis be prevented?
Postural kyphosis can be prevented by being aware of your posture and by taking care of your back. You should encourage your child to:
- avoid slouching
- sit correctly - sit upright, ensuring that the small of the back is supported
- avoid carrying heavy schoolbags that can pull on the back muscles and ligaments; the best schoolbags are well-designed backpacks
- take regular exercise (see below) to help strengthen the back and keep it flexible; activities such as swimming, running, walking, yoga and pilates are ideal for helping to prevent back problems
Causes of kyphosis
Causes of kyphosis
Kyphosis may be caused by poor posture during childhood or be the result of abnormally shaped vertebrae or developmental problems with the spine.
Your spine extends from your skull to your pelvis. It's made up of 24 individual rectangular-shaped bones called vertebrae, which are stacked on top of one another.
The vertebrae are separated by soft pads, or discs, which act as shock absorbers. The vertebrae are held together by tough bands of tissue called ligaments. Together with the spinal muscles, the ligaments give the back its strength.
In cases of kyphosis, the middle section of vertebrae, known as the thoracic vertebrae, are curved out of position.
Everyone has some amount of curvature in their spine to allow space inside the chest for organs such as the heart and lungs. There is a range of curvature which is considered normal. However, excessive curvature can lead to symptoms.
There are several reasons why the vertebrae can be affected in this way. These are discussed below.
Poor posture in childhood, such as slouching, leaning back in chairs and carrying heavy schoolbags, can cause the ligaments and muscles that support the vertebrae to stretch. This can pull the thoracic vertebrae out of their normal position, resulting in kyphosis.
Kyphosis caused by poor posture is known as postural kyphosis.
Abnormally shaped vertebrae
Kyphosis can also be caused when the vertebrae don't develop correctly. They can take on a wedged, triangular shape, rather than the normal rectangular, box-like shape. This leads to the vertebrae being out of position and is known as Scheuermann's kyphosis.
In people with Scheuermann's kyphosis, the ligaments surrounding the veterbrae can also be thicker than normal, which may contribute further to the condition.
It's not known what disrupts the normal formation of the spine. One idea is that the blood supply to the vertebrae becomes disrupted, affecting the growth of the vertebrae. There also appears to be a genetic link, as the condition occasionally runs in families.
Congenital kyphosis is caused when something disrupts the normal development of the spine before birth. In many cases, two or more of the vertebrae fuse together.
It's often unclear why certain children are affected in this way. However, some cases of congenital kyphosis run in families, so it seems genetics also play a role in this type of kyphosis.
Conditions that cause kyphosis
Conditions that can cause kyphosis include:
- osteoporosis - where the bones become weak and fragile and more likely to break (fracture)
- spondylosis - a term that describes the general 'wear and tear' that occurs in the bones, discs and ligaments of the spine as a person gets older
- spina bifida - a condition where the spine hasn't formed properly
- Paget's disease - a condition in which the development of new bone cells is disrupted, resulting in the bones becoming weak
- neurofibromatosis - a genetic disorder that affects the nervous system
- muscular dystrophy - a genetic condition that causes progressive weakening of the muscles
- tuberculosis - a bacterial infection that mainly affects the lungs
- cancer that develops inside the spine or spreads to the spine from another part of the body
Kyphosis can also sometimes develop as a result of an injury to the spine.
Kyphosis can usually be diagnosed by examining your spine and taking an X-ray.
During the examination, your GP may ask you to do a number of exercises to assess whether your balance and range of movement are affected.
Your GP may also ask you to lie down so they can see whether the curvature of your spine is caused by bad posture or a structural problem.
Although it's not always the case, if your spine straightens when you lie down, it's likely that your kyphosis is caused by poor posture (postural kyphosis).
However, if your spine stills curves while you're lying down, it's likely that kyphosis is caused by a problem with the structure of your spine, as found in the Scheuermann's or congenital types of kyphosis.
X-ray and scans
An X-ray can usually confirm the diagnosis and determine the cause of the kyphosis.
Further scans are usually only required if complex treatment, such as surgery, is being planned, or if you have additional symptoms that suggest your nervous system has been affected, such as numbness in your arms or legs.
If you need additional scans you'll probably have a:
- computerised tomography (CT) scan - where a series of X-rays are taken to build-up a detailed three-dimensional image of your spine
- magnetic resonance imaging (MRI) scan - where strong, fluctuating magnetic fields are used to produce a detailed image of the inside of your spine
If you develop kyphosis in adulthood, you'll usually need some additional tests to determine the underlying cause.
The tests you'll be referred for depend on any additional symptoms you have. They may include:
Most cases of kyphosis don't require treatment.
Kyphosis caused by poor posture (postural kyphosis) can usually be corrected by improving your posture.
If a child has kyphosis as a result of abnormally shaped vertebrae (Scheuermann's kyphosis), treatment depends on factors such as:
- the person's age
- their sex
- the severity of the curve
- how flexible the curve is
The condition usually stops progressing once a child is older and has stopped growing.
Surgery is often required for children born with congenital kyphosis.
If you have mild to moderate kyphosis, it may be possible to control your symptoms using painkillers and exercise.
Painkillers and exercise
Teenagers with mild to moderate kyphosis may need to wear a back brace. The brace is worn while the bones are still growing and prevents the curve getting worse.
Wearing a brace may feel restrictive at first. However, most people get used to them after a while. Modern braces are designed to be convenient, so it should still be possible to take part in a wide range of physical activities.
You'll need to wear the brace until the spine stops growing, which is usually around 14 or 15 years old.
Bracing isn't usually recommended for adults who have stopped growing because it won't correct the position of the spine.
Surgery can usually correct the appearance of the back and may help to relieve pain but it carries quite a high risk of complications.
Surgery is only recommended for more severe cases of kyphosis, where it's felt the potential benefits of surgery outweigh the risks.
Surgery for kyphosis would usually be recommended if:
- the curve of your spine is very pronounced
- the curve is causing persistent pain that can't be controlled with medication
- the curve is disrupting your body's other important functions, such as breathing and the nervous system
- without surgery it's likely that the structure of your spine would deteriorate further
A technique called spinal fusion is usually used to treat kyphosis. It involves joining together the vertebrae responsible for the curve of the spine.
During the operation, an incision is made in your back. The curve in your spine is straightened using metal rods, screws and hooks, and your spine is fused into place using bone grafts. Bone grafts usually use donated bone but it may taken from another place in your body, such as the pelvis.
The procedure takes four to eight hours and is carried out under general anaesthetic.
You may need to stay in hospital for up to a week after the operation, and you may have to wear a back brace for up to nine months to support your spine while it heals.
You should be able to return to school, college or work after four to six weeks, and be able to play sports about a year after surgery.
Complications of spinal fusion surgery can include:
- infection after the operation
- excessive bleeding at the site of the surgery
- accidental damage to the nerves that run through the spine, which could result in a paralysis with loss of bladder and bowel function
Before deciding whether to have spinal surgery, you should discuss the benefits and risks with the doctor in charge of your care.