Neck pain is a common issue, often stemming from problems with the discs that cushion the vertebrae in the spine. When conservative treatments fail, especially for severe C6-C7 disc issues, surgery may be considered. Two primary options are cervical disc replacement and cervical spinal fusion. Each aims to alleviate symptoms through different approaches.
Understanding C6-C7 Disc Issues
The C6-C7 discs are located in the lower cervical spine. These discs function as shock absorbers, allowing for the neck’s flexibility and range of motion. Their position and constant movement make them prone to wear and tear over time.
Conditions such as degenerative disc disease, where discs lose hydration and flexibility, or herniation, where the soft inner material of a disc pushes out, can affect this segment. When a C6-C7 disc is compromised, it can compress nearby nerves, leading to symptoms like pain, numbness, or weakness that radiates from the neck into the shoulders, arms, and hands. This nerve compression, known as radiculopathy, can cause radiating pain, tingling, or weakness in the triceps and fingers, and difficulty with fine motor tasks.
Cervical Disc Replacement
Cervical disc replacement, also known as artificial disc replacement (ADR), involves removing a damaged disc and replacing it with an artificial device. This device is typically made of metal plates with a ceramic or polymer core designed to mimic the natural movement of a healthy disc. The surgeon accesses the damaged disc through a small incision in the front of the neck.
After removing the damaged disc, the artificial disc’s two metal plates are anchored to the bony surfaces of the vertebrae above and below the treated level. The central polymer component allows for tilting, gliding, and rotating motions, aiming to preserve the natural movement of the neck. A primary goal of this procedure is to maintain motion at the treated spinal segment, which can potentially reduce stress on the adjacent discs. Patients often experience immediate pain relief and an improved quality of life, regaining the ability to perform activities with fewer limitations.
The recovery process for cervical disc replacement is often quicker compared to spinal fusion. Many patients can return to light activities within a few weeks and resume normal daily activities within two to three months. While generally considered safe, potential risks include device migration or subsidence, surgical site infections, or damage to surrounding nerves or blood vessels. Post-operative discomfort, such as difficulty swallowing, typically resolves within two weeks.
Cervical Spinal Fusion
Cervical spinal fusion, commonly referred to as Anterior Cervical Discectomy and Fusion (ACDF), addresses damaged cervical discs by removing them and permanently joining the vertebrae above and below. The surgeon makes an incision in the front of the neck to access the affected disc, which is then removed to relieve pressure on the spinal cord or nerves. After the disc is removed, a bone graft, from the patient’s body, a donor, or synthetic material, is inserted into the empty disc space.
Metal plates and screws are then used to secure the vertebrae and the bone graft, creating stability and promoting the bones to grow together, forming a single, solid bone. This fusion stabilizes the spine and alleviates symptoms caused by nerve compression from disc herniation or bone spurs. While effective in pain relief and preventing further nerve damage, a consequence of fusion is the elimination of motion at the treated segment.
Recovery from ACDF surgery typically involves a longer period than disc replacement, with full bone healing potentially taking six months to a year. Patients usually stay in the hospital for at least one night and may wear a neck collar for support during initial weeks. Light activities are encouraged early, but strenuous activities are restricted for at least six weeks, and contact sports or heavy lifting avoided for several months. Common temporary post-operative symptoms include throat soreness or mild difficulty swallowing.
Comparing Surgical Approaches
Cervical disc replacement and spinal fusion offer distinct advantages and considerations for C6-C7 disc issues. A primary difference is their impact on neck movement. Cervical disc replacement aims to preserve motion at the treated level by replacing the disc with an artificial device that mimics natural spinal movement. In contrast, cervical spinal fusion involves joining vertebrae, which eliminates motion at the fused segment, reducing neck flexibility.
Recovery timelines generally favor disc replacement, with patients often returning to daily activities within two to three months. Fusion recovery can extend from six months to a year for full bone healing. Immediate post-operative pain relief can be similar for both procedures. However, the long-term implications, particularly concerning adjacent segment disease (ASD), differ. ASD is degeneration of discs above or below the surgically treated level. While short-term rates of adjacent-level reoperation are similar, studies suggest that cervical disc replacement may lead to a lower rate of symptomatic ASD and subsequent surgeries in the long term compared to fusion.
Suitability for each procedure also varies. Disc replacement is generally considered for patients with good bone quality and without significant facet joint arthritis or multi-level disc degeneration. Fusion, on the other hand, can be a more suitable option for patients with more extensive spinal instability, significant arthritis, or specific disc conditions that preclude disc replacement. Both procedures have high success rates in alleviating pain and improving quality of life for carefully selected patients.