Kyphosis

A condition guide by Mr Mohammed Madi, Consultant Orthopaedic & Spinal Surgeon.

Kyphosis means an excessive forward (outward) curve of the spine, usually in the upper back — the rounded "hunched" shape that many people recognise. But kyphosis is not a single condition: it is a pattern that can arise for very different reasons, from poor posture in a teenager to fractures in an older person with thin bones. Because the cause determines the outlook and the treatment, this guide is organised around the different types of kyphosis, after first explaining what kyphosis is and how the spine's side-on balance works.

Seen from the side, a normal spine has gentle curves: an outward curve in the upper back (the thoracic kyphosis) balanced by inward curves in the neck and lower back. A certain amount of upper-back curve is entirely normal and healthy. Kyphosis becomes a condition when that forward curve is greater than normal, or when it appears where it should not — for example a forward angle in the lower back. The key questions are how large the curve is, whether it is flexible (correctable by standing up straight) or rigid (fixed), what is causing it, and — crucially — whether it has unbalanced the spine.

In plain terms: a little roundness in the upper back is normal. Kyphosis is when that forward curve becomes too much, or too stiff, or appears in the wrong place.

The forward curve of kyphosis cannot be judged in isolation, because the spine works as a balanced whole. When one part of the spine curves too far forward, the rest must compensate to keep the head balanced over the pelvis and the eyes looking ahead — for example by increasing the inward curve of the lower back, tilting the pelvis, or bending the knees. This front-to-back balance is called sagittal alignment, and global balance refers to the whole standing skeleton together. A kyphosis that the body can still compensate for, keeping balance, is generally far better tolerated than one that has tipped the trunk forward so that the person can no longer stand upright without effort. This is why assessment uses full-length standing X-rays and why, in adults especially, restoring balance — not just reducing the curve — is the goal of treatment. (The principles of spinal alignment are covered in more depth in the Adult Spinal Deformity guide.)

Because the cause shapes everything that follows, the sections below take each main type in turn.

The commonest and mildest form, usually in adolescents and young adults. It is caused by posture and habit rather than any structural change in the bones, so the curve is flexible — it straightens out when the person stands tall or lies over a support. There is no vertebral wedging on X-ray. It does not progress to severe deformity and is managed with postural education, exercise and strengthening; it does not require bracing or surgery.

A structural kyphosis that develops during adolescent growth, in which the front of several vertebrae grow less than the back, leaving them wedge-shaped. This makes the curve rigid — it does not correct on standing or bending backwards. Diagnosis traditionally rests on the Sorensen criteria: wedging of 5 degrees or more across at least three adjacent vertebrae, often with irregular endplates and small disc herniations into the bone (Schmorl's nodes). The typical form has its apex in the mid-thoracic spine and produces the classic rounded back; the atypical (thoracolumbar or lumbar) form, sometimes seen in athletic adolescents or heavy lifters, has a lower apex and is more likely to cause pain and to progress. Most cases are managed without surgery — observation, physiotherapy, and bracing in growing children with moderate curves. Surgery is reserved for severe curves (broadly beyond around 75 degrees), or smaller curves with persistent pain not helped by other measures, and rarely for neurological problems.

Present from birth, caused by the vertebrae failing to form or to separate properly during development. Although uncommon, it is important because it can progress relentlessly with growth and, in some patterns, carries a real risk to the spinal cord. It often needs early specialist assessment and, frequently, surgery in childhood. Children with congenital spinal anomalies are also checked for associated heart, kidney and spinal-cord abnormalities.

Arises in conditions that affect the nerves and muscles controlling the trunk — such as cerebral palsy, muscular dystrophy, spinal muscular atrophy or spina bifida — where weak or unbalanced trunk control allows the spine to collapse forward. These curves tend to be long, flexible early on but progressive, and they affect sitting balance, comfort and breathing. Management is part of the person's wider care and often involves seating, support and, in selected cases, surgery to stabilise the spine.

A forward angle that develops after a vertebra is crushed — either by a significant injury in a younger person, or by an osteoporotic compression fracture in an older person with thinned bones. Multiple osteoporotic fractures can stack up to produce the progressive forward stoop and loss of height seen in later life. Treating the underlying osteoporosis is central; many single fractures settle with time and supportive care, while a minority of painful or progressive cases are considered for procedures or, rarely, reconstructive surgery. (Osteoporotic fractures are covered further in their own guide.)

Develops in adult life from age-related wear: as discs lose height and the lower-back curve flattens, the spine gradually tips forward. It often overlaps with degenerative scoliosis and spinal stenosis, and is a common cause of the adult forward-stooping posture. It is closely related to the loss of lumbar lordosis discussed under Adult Spinal Deformity, and treatment follows the same principles — non-surgical care first, with reconstructive surgery reserved for disabling, progressive or unbalanced deformity.

Deformity that arises after previous spinal surgery. The two important patterns are flatback — loss of the normal lower-back curve after a fusion, leaving the trunk pitched forward — and proximal junctional kyphosis, where the spine bends forward just above the top of a fusion. Both are recognised challenges of spinal surgery and are important reasons for careful planning of alignment when fusion is performed.

In this inflammatory condition the spine can gradually stiffen and fuse in a forward-flexed position, sometimes leaving a fixed, rigid stoop that makes it hard to look ahead. Good medical control of the inflammation helps prevent this; established, disabling deformity is occasionally corrected with specialised osteotomy surgery in carefully selected patients.

Symptoms depend on the type and severity, and may include a visible rounding or stooping of the back, back pain or aching (often from the muscles working to hold the body up), stiffness, fatigue, and — in advanced cases — difficulty standing straight or looking ahead, and, where the curve is very severe, effects on breathing. Most kyphosis is painless or mildly achy and not dangerous; the warning signs that matter are any symptoms of pressure on the spinal cord or nerves.

Seek prompt assessment for new or progressive weakness, numbness or tingling in the limbs, problems with balance or walking, or any disturbance of bladder or bowel control. These suggest the spinal cord or nerves may be involved and are uncommon but important — particularly in congenital, severe, or rapidly changing curves.

Assessment combines a history and examination — including whether the curve corrects on bending backwards (flexible) or stays fixed (rigid), and a full neurological check — with imaging. Standing X-rays, ideally full-length, measure the curve (the Cobb angle) and the overall sagittal balance; bending or extension films assess flexibility. MRI is used where there are neurological concerns or before surgery, to look at the spinal cord and discs. CT gives fine bone detail for congenital or surgical cases, and a bone-density scan is important where osteoporosis is suspected.

Because the cause varies so much, so does the treatment:

Observation and physiotherapy suit postural kyphosis and many mild structural curves, focusing on posture, strength and flexibility.

Bracing has a role in growing children with moderate, flexible structural curves (notably Scheuermann's), aiming to limit progression during growth.

Treating the underlying cause is central in osteoporotic, inflammatory and neuromuscular kyphosis.

Surgery is reserved for severe, progressive, painful or unbalanced deformity, for congenital curves that threaten the cord, and for neurological problems. The goals are to halt progression, relieve pressure on the nerves where needed, and restore a balanced, upright posture; in adults this means restoring sagittal alignment, not simply reducing the curve. Deformity surgery is major surgery with real risks, including proximal junctional kyphosis above the fusion, and decisions are carefully individualised.

The outlook depends entirely on the type. Postural kyphosis does not progress and does well with simple measures. Scheuermann's usually stabilises after growth and most people live full, active lives, with surgery needed only for the most severe curves. Congenital and neuromuscular kyphosis need close specialist follow-up. Degenerative and osteoporotic kyphosis are managed as part of wider spinal and bone health. Across the board, the key is matching the treatment to the cause and protecting the spine's balance.

"All kyphosis is the same." No — the types differ greatly in cause, outlook and treatment.

"A round back just means bad posture." Postural kyphosis is flexible and harmless, but a rigid curve (such as Scheuermann's) is structural and assessed differently.

"Kyphosis always needs surgery." Most kyphosis is managed without surgery, which is reserved for severe or progressive cases.

"Stooping in older age is just ageing." Progressive stooping is often from osteoporotic fractures or degenerative deformity — both treatable.

"The bigger the curve, the worse the symptoms." Balance matters as much as the size of the curve; a balanced larger curve can trouble someone less than an unbalanced smaller one.

Kyphosis is an excessive forward curve of the spine, and it comes in distinct types — postural, Scheuermann's, congenital, neuromuscular, post-traumatic and osteoporotic, degenerative, post-surgical, and that seen in ankylosing spondylitis — each with its own cause, outlook and treatment. A normal amount of upper-back curve is healthy; what matters is the size of the curve, whether it is flexible or rigid, the cause, and whether the spine remains balanced. Most kyphosis is managed without surgery; surgery is reserved for severe, progressive, painful or unbalanced deformity and for curves threatening the nerves. The warning signs to act on are any symptoms of nerve or spinal-cord involvement.

This page is for general education and does not replace advice from your own clinical team. Seek prompt review if you develop new or progressing weakness, numbness, balance or walking problems, or any disturbance of bladder or bowel control.

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This information is for general patient education and is not a substitute for an individual consultation. Always seek personalised advice from a qualified spinal specialist.