Anterior Cervical Discectomy and Fusion

Over the next few issues, I will share a series of neurosurgical procedures, including those for the cervical and lumbar spine, brain, and minimally invasive vascular surgeries. This issue will explain anterior cervical disc removal and spinal fusion surgery.

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Causes and Symptoms of Cervical Spine Disorders

Anterior Cervical Discectomy and Fusion (ACDF) is a surgical procedure to treat cervical spine disorders. These disorders are often caused by degeneration, overuse, or injury. Problems can occur in cervical discs, facet joints, or the vertebral bodies. Since the cervical spine encases the central nervous system that controls our limbs, torso, and urinary functions, patients with cervical spine disorders may experience symptoms of instability such as muscle tension, neck and back pain, shoulder pain, and headaches. Nerve compression can lead to sensory and motor dysfunction, manifesting as numbness and tingling in the limbs, muscle weakness, balance issues, walking difficulties, frequent urination, nocturia, and constipation. Dysfunction of reflex and autonomic nerves can also cause dizziness, tinnitus, gastrointestinal discomfort, and emotional instability.

Case Share

Mr. Lu, a 55-year-old engineer, sought consultation in November 2016 after experiencing numbness and tingling in his hands, especially the right thumb and index finger, for two years, which later progressed to weakness and instability while walking. Despite consulting various Western and Chinese medical specialists and undergoing physical and chiropractic therapies for two years, clinical neurological reflex tests indicated severe central cervical nerve compression. Subsequent magnetic resonance imaging confirmed severe degeneration and disc herniation at the fourth/fifth and fifth/sixth cervical vertebrae, compressing the spinal cord and causing deformation, flattening, and oedema (see Image 1).

Given the severity, I recommended a definitive cervical decompression and spinal stabilization surgery. However, after consulting with friends and family, Mr. Lu declined surgery fearing potential risks of nerve damage leading to paralysis. Opting for continued conservative treatment, his condition worsened, leading to difficulties in holding a pen, using chopsticks, and several falls causing head injuries. His cervical spine issue was a ticking time bomb; any minor injury could permanently damage the central spinal nerves, risking permanent paralysis. It was imperative to defuse this bomb swiftly.

Eventually, Mr. Lu followed my medical advice and underwent a four-hour minimally invasive neurosurgical operation - Anterior Cervical Discectomy and Fusion. The surgery aimed to decompress the central spinal nerves and stabilize the cervical spine. After spending one-night resting post-surgery, Mr. Lu found significant improvement in limb sensation and muscle strength the next morning. Under my supervision, he was able to walk with noticeably better balance and stability. X-ray and MRI observations showed considerable improvement in spinal cord compression at the fourth/fifth and fifth/sixth cervical segments (see Image 2). Mr. Lu was discharged home 24 hours post-surgery.

What Is "ACDF"?

Under general anaesthesia and guided by X-ray, the surgery typically lasts three to four hours. Through a small incision of two to three centimetres along the neck crease, neurosurgeons carefully decompress the central and cervical nerves, removing diseased discs and bone spurs. Utilizing a microscope throughout, surgeons perform the surgery with precision under two millimetres to ensure full protection and decompression of the spinal and surrounding cervical nerves. An artificial disc is then inserted to fill the gap between the vertebrae, stabilizing the cervical spine.

Compared to traditional non-minimally invasive surgery without a microscope, where a small piece of the patient's pelvic bone is used to fill the gap for stabilization and fusion, causing additional pain from the pelvic incision. Moreover, patients had to wear a cervical collar for three months to ensure stability until fusion. The introduction of artificial discs is designed to complement microscopic minimally invasive neurosurgery, eliminating the need for additional pelvic incisions. Especially, artificial discs provide immediate stabilisation, avoiding the inconvenience of wearing a cervical collar. Artificial discs are categorized into non-mobile and mobile types:

Non-mobile artificial discs are made from synthetic reinforced plastic, artificial bone, and titanium wires. The artificial bone in the disc stimulates the patient's own bone growth within six months, fusing the adjacent vertebrae together to enhance stability. The titanium wire component also provides immediate stabilization, so patients don't need to wear a cervical collar.

Mobile artificial discs, made from synthetic reinforced plastic, reinforced ceramics, and titanium, allow for continued elasticity and movement between the vertebrae. Before surgery, doctors discuss with patients to decide on the number of cervical segments to operate on and whether to use fixed or non-fixed artificial discs based on the patient's condition and needs. Generally, if a patient suffers from neck pain or headaches due to instability, or if the central spinal nerves are severely compressed, non-mobile discs are preferred to eliminate instability and prevent further nerve damage. If more than one cervical segment needs surgery, such as involving three segments, the surgeon may suggest using one or two mobile artificial discs and the rest non-mobile, maintaining both cervical stability and a degree of flexibility (see Image 3).

The Primary Goal Is to Protect Central Nerves

In summary, the primary goal of neurosurgeons is to protect the central nerves. Compared to brain surgery, where operations are conducted in the narrow spaces among the brainstem, hair-thin central nerves, and cerebral blood vessels, minimally invasive cervical neurosurgery is relatively safe and low-risk. Doctors plan the most appropriate and safe medical approach based on the patient's condition to effectively treat symptoms and remove the cervical "time bomb," aiding patients in quickly recovering to enjoy a normal life and work.