What Is Scoliosis Surgery?

Introduction

Are you suffering from constant backache? Are you curious if it's due to scoliosis or other causes? In this article, we aim to shed light on scoliosis, its treatment and outcome. 

Scoliosis is commonly known as the curvature of the spine and can range from mild to severe. While methods of treatment vary case by case, scoliosis surgery is one of the main treatments for severe cases.¹ 

Understanding scoliosis

According to its cause, scoliosis can be categorised as secondary or idiopathic. There are other classifications for idiopathic scoliosis: early onset, late onset, infantile, juvenile, and adolescent kinds. In a survey of 10,000 children in Edinburgh, the frequency of scoliosis in the UK was found to be 1.3/1000 in children under the age of eight and 1.8/1000 in those over eight. The incidence was similar for both sexes in the first group, while females outnumbered boys in the second group by nearly three to one. With a few notable exceptions, these numbers are comparable worldwide.¹

Scoliosis is a deviance from the spine's normal vertical line and is characterised by a lateral curvature and rotation of the vertebrae within the curve. Generally speaking, a posterior-anterior radiograph demonstrating vertebral rotation and at least 10° of spinal angulation is required to diagnose scoliosis. Scoliosis has a variety of origins, which can be broadly categorised as congenital, neuromuscular, syndrome-related, idiopathic, or spinal curvature resulting from secondary causes. A vertebral anomaly that causes a mechanical deviation from the usual spinal alignment is the cause of congenital scoliosis. Neurological disorders (like cerebral palsy or paralysis), muscular deformities (like Duchenne muscular dystrophy), or other syndromes (like Marfan syndrome and neurofibromatosis) can all cause scoliosis.²

On occasion, severe lateral deviation of the spine can happen without any abnormalities in the bones and with little to no rotation of the spine. In these situations, the "scoliosis" may be brought on by infection, discomfort, anomalies in the spinal cord, and tumours (both intraspinal and extraspinal). Most cases of scoliosis that general practitioners see are idiopathic, meaning they lack a clear cause.²

The most prevalent type of scoliosis is called adolescent idiopathic scoliosis (AIS), which is a three-dimensional structural deformity of the trunk and spine that affects otherwise healthy individuals during puberty. In contrast, early-onset idiopathic scoliosis develops before puberty. Specific curve patterns have been used to classify AIS, and these patterns may show as more or less prominent in clinical settings.³

Scoliosis can present itself through multiple symptoms, and these include:^4,5

• Uneven shoulders: one shoulder may appear higher than the other.
• Uneven waist: the patient’s hips may be uneven or have an asymmetrical appearance.
• Uneven leg length: one leg may appear longer than the other.
• Spinal curve: the spine may have an "S" or "C" shape when viewed from the back.
• Tilted/rotated pelvis: the pelvis may appear tilted or rotated.
• Prominent ribs: one side of the ribcage may protrude more than the other.
• Muscle imbalances: muscles on one side of the spine may be more developed than the other.
• Back pain: some individuals with scoliosis may experience back pain, particularly in the lower or middle back.
• Fatigue: muscles involved in maintaining posture may become fatigued which will lead to discomfort and tiredness.

It is worth noting that scoliosis can be mild and unnoticeable. However, severe scoliosis can cause physical deformities that can limit the function of the lungs and heart.⁴  

Diagnosis of scoliosis can be performed through multiple approaches:⁵

• Historical background & traditional methods of measuring the degree of spinal curvature: such as Cobb angle measurement and Adams Forward Bend test.
• Surface topography imaging and spinal deformity assessment: such as Body surface topography (ST).
• Radiography and Imaging methods: X-rays and Magnetic Resonance Imaging (MRI).
• Computed Tomography (CT).
• Artificial Intelligence (AI) for scoliosis detection: using artificial neural networks (ANNs) or simulated neural networks (SNNs).

Non-surgical treatment options

Non-surgical options are available for scoliosis treatment:

• Bracing: this is a form of treatment proposed for adolescent idiopathic scoliosis, along with observation (and surgery if required). Observation is usually recommended for young patients with progressive curves between 25 and 50 degrees
• Physical Therapy
• Monitoring

It is worth noting that these options vary between individuals and are recommended by a professional on a case-by-case basis.²

When is scoliosis surgery considered?

Currently, when the curve magnitude surpasses 40–45 degrees, spinal fusion surgery is advised. Early attempts at spinal fusion surgery did not live up to expectations, with the goal being to leave patients with a slight residual deformity. Since then, these objectives have been changed to more reasonable ones preventing progression, restoring 'acceptability' of the clinical deformity and reducing curvature.³ Additionally, with improved technology and understanding of scoliosis and its treatment, other options such as vertebral body stapling can be considered as they showed a success rate of 87% in lumbar curves treatment.⁹

Types of scoliosis surgery

Spinal Fusion⁶

• Spinal fusion is the most common type of surgery for scoliosis. It involves joining two or more vertebrae together to form a single, solid bone. This limits the movement between the fused vertebrae and prevents further progression of the curve. Bone grafts, metal rods, and screws are often used in the fusion process.
• Instrumentation: Metal rods, screws, and hooks are often used to straighten and stabilise the spine during spinal fusion surgery. These instruments are attached to the spine and help maintain the corrected alignment while the fusion occurs.

Anterior and Posterior Approaches⁶

• Anterior Approach: In some cases, surgery may be performed from the front of the body (anterior approach). This approach allows the surgeon to access the spine from the front, often using a thoracoscopic or laparoscopic technique.
• Posterior Approach: This is the more traditional approach where surgery is performed from the back of the body. The surgeon gains access to the spine through an incision in the back.

Hemivertebrae Resection⁷

• If scoliosis is caused by the presence of a wedge-shaped vertebra (hemivertebra), the surgeon may remove the abnormal vertebra and then perform a spinal fusion to correct the curvature.

Growing Rods or Tethering⁸

• In the case of paediatric scoliosis, especially when the patient is still growing, growing rods may be used. These rods are lengthened periodically to accommodate the child's growth. Tethering is a newer technique that involves attaching a flexible cord to the spine to guide its growth while allowing some movement.

Vertebral Body Stapling⁹

• This is a less invasive surgical option for some cases of idiopathic scoliosis. Staples are placed across the growth plates of the vertebrae to modify their growth and prevent further progression of the curve.

Vertebral Column Resection¹⁰

• In severe and rigid cases of scoliosis, where traditional fusion may not be sufficient, a portion of the vertebrae may be removed (vertebral column resection) to allow for better correction.

Preparing for scoliosis surgery

Before entering surgery for scoliosis, some steps are considered to have a successful operation:^11,12

• Medical evaluation to assess the individual’s health.
• Communication with the healthcare team to address any concerns that the patient or their family might have.
• Pre-operative tests such as blood tests, imaging tests etc.
• Medication review.
• Psychological support.
• Postoperative care planning.

The scoliosis surgery process

The surgical procedure of scoliosis includes the following steps:^13,14

• Anaesthesia
• Incision
• Exposure of the spine and correction of the curvature using bone graft fusion and instrumentation (screws, rods etc)
• Closure of the incision
• Post-surgery monitoring
• Recovery, rehabilitation and follow-up care

Recovery and rehabilitation

The recovery process involves a hospital stay, during which the patient receives pain management, physical therapy, and instructions on postoperative care. The length of hospitalisation depends on the type of surgery and the patient's progress. After discharge, the patient will have regular follow-up appointments with the surgeon to monitor the healing process, address any concerns, and adjust the treatment plan as needed.¹³

Risks and complications

As with any surgery, scoliosis surgery can also carry its own set of risks:^13,6

• Blood loss
• respiratory depression
• Late complications: adjacent segment disease (i.e. spinal stenosis and proximal junctional kyphosis), pseudarthrosis and instrumentation failure
• Infection
• Nerve damage

Long-term outcomes

Following surgery, a study has shown that the average major curve correction was 26.6° (2,188 patients), which is around 40.7% correction of the original curve. Throughout a 2-year follow-up, clinical outcomes are improved in adults after surgery. However, there is a lack of standardised outcome measures and assessments in the adult scoliosis literature.¹⁵

Overall, the quality of life for patients post-surgery improves, with key points for this including:

• Curvature correction
• Improvement in appearance
• Pain relief
• Recovery and rehabilitation
• Long term follow-up

Summary

Scoliosis, a deviation of the spine, can be quite debilitating to some patients; it can hinder the lateral curvature and rotation of the vertebrae. While scoliosis can be linked to many diagnoses, the majority of patients have idiopathic origin. A set of physical examinations, radiographs and medical history checks are required to assess non-idiopathic roots of scoliosis. The treatment for idiopathic scoliosis is based on age, magnitude/severity of the curve and risk of progression, and includes observation, orthotic management, and surgical correction. Treatment of scoliosis, majorly by surgery and accompanied by follow-ups, can improve curvature and alleviate pain and other associated symptoms.