Spinal Deformities | Definitions and Symptoms

Spinal deformities refer to abnormal curvature of the vertebral column, caused by twisting, bending, or angulation of the spinal bones. When viewed from behind, the healthy spine runs straight down the middle of the back. But when viewed from the side, the spine has normal physiological curves – the cervical and lumbar regions have a lordotic inward curve while the thoracic region has a kyphotic outward curve.

Normal Spinal Curves

Normal spinal curves work in harmony to absorb shock, maintain balance, and allow range of motion. But spinal deformities disturb this alignment, forcing the back into exaggerated abnormal arcs or angles. There is no singular threshold that defines abnormal curvature since normal curvature ranges exist. However, most specialists consider curves beyond 10-20 degrees as warranting further evaluation and potential treatment.

Spinal Deformities

Deformities can affect the cervical, thoracic, or lumbar regions in isolation or combination. They also occur within different planes – the sagittal plane viewed from the side shows kyphotic or lordotic curves while the coronal plane viewed head-on shows lateral deviations called scoliosis. These abnormal spinal curves lead to postural changes and instability that worsen over time.

The most well-known spinal deformities are scoliosis demonstrating lateral curvature, kyphosis showing excessive forward rounding, and lordosis demonstrating extreme low back arching. But many other variants exist like kyphoscoliosis, showing both frontal and sagittal deformities. Congenital, idiopathic, degenerative, neuromuscular, and traumatic subtypes of these deformities also occur.

Types of Spinal Deformities

Scoliosis

Scoliosis is characterized by an abnormal, sideways curvature of the spine. When viewed from behind, the spine of someone with scoliosis has a C-shaped or S-shaped curve, rather than being straight.

Scoliosis can occur at any age, but it most commonly develops in children and teens while their skeleton is still growing. Girls are more likely to develop scoliosis than boys. In most cases, the cause is unknown, which is called idiopathic scoliosis. Other potential causes include neuromuscular conditions, genetic conditions, and unequal leg length.

Kyphosis

Kyphosis refers to an excessive outward curve of the thoracic spine, leading to a visible hump. This condition typically causes a hunched or slouching posture. Scheuermann’s kyphosis, the most common form in teenagers, results from wedged-shaped vertebral bodies deforming under pressure. When kyphosis develops from osteoporosis leading to vertebral compression fractures, it is called postural kyphosis.

Those with kyphosis appear to have a hunchback. They often tilt their head back to maintain a forward line of sight since excessive thoracic spine curvature pushes the ribcage forward. Back pain is common as well due to increased pressure on the vertebrae. Difficulty breathing can also occur if ribcage mobility is impaired severely.

Lordosis

Lordosis refers to an abnormal, excessive inward curve of the lumbar spine. The upper body tips backwards while the buttocks protrude outward. This creates an exaggerated arch in the lower back, known as swayback posture.

When lordosis develops in late childhood just before puberty, it is often mild and requires just monitoring or physical therapy. However, painful adult degenerative lordosis becomes more likely when obesity, osteoporosis, muscle weakness, or prior spine surgery has occurred.

Causes of Spinal Deformities

There are several potential causes leading to the development of spinal deformities. These can be broadly categorized as congenital, degenerative, neuromuscular, traumatic, or idiopathic.

Congenital Causes

Congenital spinal deformities are present at birth, caused by either genetic factors or events during fetal development. Vertebrae may fail to properly divide or fuse together abnormally. Muscle imbalances from neurological problems can also pull bones out of place before birth.

Degenerative Causes

As people age, disc degeneration, arthritis, and loss of bone density lead to gradual instability and curved deformity. Pressure on weakened vertebrae causes compression fractures and wedging over time. Prior spine surgery also contributes by altering structural support.

Neuromuscular Causes

Diseases like muscular dystrophy, cerebral palsy, and spinal cord injuries cause muscle tightness, spasticity, and paralysis surrounding the spine. The abnormal forces lead to progressive curved deformity as growth continues.

Traumatic Causes

Severe trauma like a blow to the back or a vertebral fracture can displacement bones or discs. The injury may heal with permanent deformation. Long term effects of poor lifting mechanics, carrying heavy weights or contact sports can also lead to spine deformities.

Idiopathic Causes

Up to 80-85% of scoliosis cases have no identifiable origin. While suspected causes like genetic predisposition exist, the reason idiopathic scoliosis arises still remains unclear. Idiopathic kyphosis and lordosis can also rarely occur.

Identifying the underlying cause of a spinal deformity guides appropriate treatment and helps predict progression risk in younger patients. While some curvature related to congenital, neuromuscular or traumatic causes will continue worsening with growth, idiopathic and degenerative cases may remain stable long term.

Symptoms

Those with spinal deformities may first notice changes in posture, stance or uneven hips or shoulders upon glancing in a mirror. Mild to severe back pain is also very common, starting as soreness but worsening over time. The abnormal spinal curves can rotate the ribcage or pelvis, leading to visible protrusions on one side of the torso.

In more severe cases, breathing difficulty, gait abnormalities, radiculopathies, and neurological symptoms can develop as nerves or organs become increasingly compressed or irritated. Early diagnosis is key, as progression of these deformities causes worsening pain, disability and health complications.

Diagnosis

To accurately diagnose spinal deformities, detailed imaging paired with a thorough clinical evaluation is necessary. Doctors will start by asking questions about symptoms, performing a physical exam assessing posture and spine flexibility, checking reflexes and muscle strength and looking for any neurological indications.

X-rays serve as the standard diagnostic imaging test, allowing precise measurements of abnormal spinal curves. An MRI or CT scan provides enhanced visualization of surrounding tissues. Specialists can determine the degree of deformity and whether braces or surgery are warranted based on imaging and exam findings.

Conclusion

Spinal deformities such as scoliosis, kyphosis and lordosis involve an abnormal curve of either the upper, middle or lower back. Early symptoms may start mildly but these conditions tend to worsen over time, eventually causing severe pain and disability if left untreated. Seeing a specialist for appropriate diagnostic testing and to discuss treatment options provides the best chance of halting progression.