Kyphoscoliosis

What kyphoscoliosis is

Seen from behind, a healthy spine is straight. Seen from the side, it has gentle curves: a forward curve in the neck, a backward rounding (kyphosis) in the upper back of about 20 to 45 degrees, and a forward curve in the lower back.

• Scoliosis is a sideways curve of 10 degrees or more, usually with rotation of the vertebrae.
• Kyphosis in the medical sense means upper-back rounding beyond the normal range, giving a hunched look.
• Kyphoscoliosis combines the two. The twisted, rounded spine also distorts the rib cage.

Kyphoscoliosis vs scoliosis

Causes

• Idiopathic: no clear cause. Some adolescent idiopathic scoliosis curves have a kyphotic component.
• Congenital: vertebrae that formed abnormally before birth, such as half-formed (hemivertebrae) or fused segments. These curves can progress quickly in childhood.
• Neuromuscular: weak or imbalanced trunk muscles in cerebral palsy, muscular dystrophy, spinal muscular atrophy, spina bifida, polio and spinal cord injury.
• Syndromes and connective tissue disorders: neurofibromatosis type 1, Marfan syndrome, Ehlers-Danlos syndrome (including a kyphoscoliotic type), and skeletal dysplasias.
• Adult degenerative: worn discs and joints, often with osteoporotic fractures, in older adults.
• Other: past spinal tuberculosis, radiation, surgery or trauma.

Symptoms

• Uneven shoulders, shoulder blades or waistline
• A rounded or hunched upper back, and a rib hump when bending forward
• The head sitting forward of the pelvis, or leaning to one side
• Back pain, stiffness and muscle fatigue, more common in adults
• Breathlessness with exertion, then at rest in severe cases
• Reduced height and clothes not fitting evenly

How kyphoscoliosis affects breathing

A severe curve shrinks and stiffens the chest cage and puts the breathing muscles at a mechanical disadvantage. This causes a restrictive lung pattern: smaller lung volumes. Risk rises substantially once the main curve is above about 100 degrees, earlier if the curve began in early childhood, high in the thoracic spine, or with muscle weakness.

Breathing worsens first during sleep. Signs include morning headaches, poor sleep, daytime sleepiness and poor concentration. Over years, low oxygen and high carbon dioxide strain the right side of the heart, causing pulmonary hypertension and cor pulmonale, and eventually chronic respiratory failure.

Diagnosis

1. Examination: posture, shoulder and hip levels, the forward bend (Adams) test, flexibility, and a neurological check of legs and reflexes.
2. Standing full-spine X-rays: front and side views measure the sideways curve and the kyphosis with the Cobb angle.
3. MRI: if there are neurological signs, a congenital curve, an unusual curve pattern, or before surgery, to look for problems such as a tethered cord or syrinx.
4. Lung function tests: spirometry showing forced vital capacity (FVC). Overnight oximetry or a sleep study if sleep-related breathing problems are suspected.
5. Echocardiogram if heart strain is suspected.

Treatment

Children and teenagers

• Observation: with repeat X-rays every 4 to 12 months while growing.
• Bracing: can slow progression of flexible idiopathic curves during growth, but works less well for congenital or neuromuscular curves.
• Casting in infants with early-onset curves.
• Growth-friendly surgery: growing rods or magnetically lengthened rods in young children, to control the curve while allowing the chest to grow.
• Spinal fusion: for large or progressive curves.

Adults

• Physical therapy for core strength, posture and flexibility
• Pain relief: acetaminophen (paracetamol) or NSAIDs at the label dose if safe for you
• Treating osteoporosis when present
• Surgery for progressive deformity, severe pain, nerve compression or imbalance that limits standing and walking

Breathing support

People with significant lung restriction benefit from vaccinations against flu, pneumococcus and COVID-19, early treatment of chest infections, staying active and keeping a healthy weight. Non-invasive ventilation (NIV) at night, using a mask and a small ventilator, corrects underbreathing during sleep, improves daytime symptoms and prolongs life. Oxygen alone can worsen carbon dioxide build-up and is used with care.

Outlook

Mild kyphoscoliosis is compatible with a normal life. The outlook in severe cases depends on the cause, curve size, age of onset and lung function. Early surgery can prevent progression, though it rarely improves lung function much once restriction is established. Night-time ventilation has greatly improved survival in people with severe chest wall restriction.

Frequently asked questions

What causes kyphoscoliosis?

Many cases have no known cause. Others come from vertebrae that formed abnormally before birth, from muscle and nerve conditions such as cerebral palsy or muscular dystrophy, from connective tissue disorders such as neurofibromatosis and Marfan syndrome, or from age-related disc degeneration and osteoporosis.

Is kyphoscoliosis serious?

It ranges from mild to severe. Small curves are mostly a cosmetic issue with occasional back pain. Large curves, especially those starting in early childhood, can restrict the lungs and lead to breathing failure and heart strain if not monitored and treated.

Can kyphoscoliosis be corrected?

Surgery with rods and screws can straighten the spine significantly and stop progression. In growing children, bracing can control some curves. Exercise and physical therapy improve pain, posture and strength but do not reverse an established structural curve.

How does kyphoscoliosis affect the lungs?

A large curve squashes and stiffens the rib cage, reducing the room the lungs have to expand. Breathing becomes shallow, first during sleep. Over time oxygen falls and carbon dioxide rises. Nighttime non-invasive ventilation is the most effective treatment for this.

Does kyphoscoliosis get worse with age?

It can. Curves often progress during growth spurts, and some adult curves advance slowly by about a degree a year, faster with osteoporosis or disc degeneration. Regular X-rays and lung function checks help catch worsening early.