Artificial Disc Replacement vs. Spinal Fusion: Which Is Right for You?

Artificial disc replacement, also called disc arthroplasty, involves removing a damaged disc and replacing it with a mechanical implant. The implant is designed to restore disc height while allowing movement between the vertebrae.

In the cervical spine, FDA-approved artificial discs may be used at one or two levels in appropriately selected, skeletally mature patients. They are commonly considered for conditions such as a cervical disc herniation or degenerative disc disease causing persistent radiculopathy or, in certain cases, myelopathy.

The primary goals of artificial disc replacement are to:



• Relieve pressure on the spinal cord or nerves
• Reduce neck and arm symptoms
• Maintain motion at the treated spinal level
• Restore appropriate disc height
• Avoid the need for the vertebrae to fuse together

Although an artificial disc is intended to preserve movement, the amount of motion achieved after surgery varies among patients.

Spinal fusion permanently joins two or more vertebrae so that they heal into one stable segment. In the neck, the most common form is an anterior cervical discectomy and fusion, or ACDF.

During ACDF, the surgeon removes the damaged disc and any bone spurs or tissue compressing the spinal cord or nerves. A spacer or cage is placed into the empty disc space, often along with bone graft material. A plate, screws, or another fixation device may be used to hold the vertebrae stable while the bones fuse.

Fusion is often used when the spine needs additional stability, such as after removal of a severely damaged disc or when arthritis, deformity, abnormal motion, or instability is present.

Both procedures are designed to treat symptoms caused by spinal cord or nerve compression. These symptoms may include:

• Neck pain
• Pain traveling into the shoulder or arm
• Numbness or tingling in the hand
• Arm or hand weakness
• Difficulty with balance or coordination
• Loss of fine motor control
• Symptoms of cervical myelopathy

In both operations, the surgeon removes the problematic disc and decompresses the affected nerves or spinal cord. The principal goal is to relieve pressure on the neurological structures.

Both procedures also carry many of the same general surgical risks, including infection, bleeding, nerve injury, spinal cord injury, swallowing difficulty, hoarseness, blood vessel injury, persistent symptoms, and the possible need for additional surgery.

The main difference is motion preservation.

An artificial disc is intended to allow the treated spinal level to continue moving. A fusion eliminates motion at that level by allowing the adjacent vertebrae to grow together.

Preserving motion may make artificial disc replacement attractive to younger or more active patients. It may also reduce stress on the spinal levels above and below the surgery. However, artificial disc replacement is only appropriate when the surrounding anatomy can safely support a mobile implant.

Fusion sacrifices movement at the treated level but provides strong, dependable stabilization. For patients with instability, significant arthritis, deformity, or poor bone quality, that added stability may be more important than preserving motion.

Potential advantages may include:

Preservation of Motion

The artificial disc allows movement at the operated level instead of permanently immobilizing it. The FDA describes cervical artificial discs as devices intended to relieve symptoms while maintaining motion after the damaged disc has been removed.

No Need to Wait for a Fusion to Heal

Because the procedure does not depend on two vertebrae growing together, patients do not face the same risk of a failed fusion, also called pseudarthrosis.

Potentially Faster Return to Activity

Some patients can return to normal activities sooner because there is no fusion that must mature. Recovery still depends on the extent of surgery, neurological symptoms, work demands, and the surgeon’s postoperative recommendations.

Reduced Risk of Future Surgery in Selected Patients

Long-term clinical trials and systematic reviews have found that cervical disc replacement can provide outcomes comparable to or, in some studies, better than ACDF in carefully selected patients. Some analyses have also reported lower rates of reoperation and adjacent-segment degeneration after cervical disc replacement.

These findings do not mean that artificial disc replacement prevents all future degeneration. The levels above and below the surgery may still develop age-related wear over time.

Potential advantages of fusion include:

Reliable stabilization

Fusion is often the preferred option when there is abnormal movement, significant instability, severe disc collapse, spinal deformity, or advanced arthritis.

A Long History of Successful Use

ACDF is a well-established operation with decades of clinical experience. It can provide excellent relief of arm pain and neurological symptoms when those symptoms are caused by nerve or spinal cord compression.

Ability to Treat More Complex Degeneration

Fusion may be more appropriate for patients with severe facet-joint arthritis, large bone spurs, kyphosis, significant instability, osteoporosis, or disease affecting multiple spinal levels.

Broader Candidacy

Many patients who are not candidates for an artificial disc can still be treated safely and effectively with fusion.

An ideal candidate commonly has:



• Symptoms caused by one or two damaged cervical discs
• A disc herniation or localized degenerative disc disease
• Persistent arm pain, numbness, weakness, or other neurological symptoms
• Symptoms that have not improved sufficiently with nonsurgical treatment
• Good bone quality
• Preserved movement at the affected level
• Healthy or minimally arthritic facet joints
• Acceptable spinal alignment
• No significant instability

The decision requires a detailed review of the patient’s symptoms, physical examination, MRI, X-rays, and sometimes flexion-extension X-rays or CT imaging.

Fusion may be recommended when a patient has:



• Significant spinal instability
• Severe facet-joint arthritis
• Advanced spondylosis or extensive bone-spur formation
• Severe loss of disc height
• Abnormal spinal alignment or kyphosis
• Osteoporosis or poor bone quality
• Previous surgery that changes the anatomy
• Disease involving more levels than an artificial disc can appropriately treat
• Infection, tumor, fracture, or another condition requiring rigid stabilization
• A spinal level that already has little or no motion

Artificial disc replacement should not be selected simply because preserving motion sounds preferable. Placing a mobile implant into a level that is already unstable, deformed, or severely arthritic can lead to poor results.

Adjacent segment disease occurs when a spinal level next to a prior surgery becomes symptomatic from degeneration, disc herniation, stenosis, or instability.



Because an artificial disc preserves motion, it may place less mechanical stress on neighboring levels than a fusion. Some long-term studies have reported lower rates of adjacent-level degeneration or reoperation after cervical disc replacement compared with ACDF.

However, adjacent-level degeneration is influenced by several factors, including aging, genetics, preexisting arthritis, spinal alignment, activity, and smoking. Artificial disc replacement may reduce risk in selected patients, but it cannot guarantee that another spinal level will never deteriorate.

Recovery varies considerably.

Patients undergoing artificial disc replacement may be able to resume neck movement and certain activities sooner because they do not need to wait for a fusion to become solid. Some patients also require a cervical collar for a shorter period or not at all.

After fusion, bone healing continues for several months. Activity restrictions may remain in place while imaging confirms that the fusion is progressing appropriately.

However, the surgical approach, number of treated levels, severity of neurological symptoms, overall health, and type of work often affect recovery more than the implant itself.

Artificial discs are designed for long-term use, but they are still mechanical implants. Potential problems can include:



• Implant movement or migration
• Subsidence into the adjacent vertebral bone
• Wear or mechanical failure
• Bone formation around the implant
• Loss of motion at the treated level
• Persistent pain
• The need for revision surgery

Some patients develop heterotopic ossification, which is bone formation around the artificial disc. If enough bone forms, the treated level may gradually lose motion and function more like a fusion.

In addition to general surgical risks, fusion has procedure-specific concerns that may include:



• Failure of the bones to fuse
• Hardware failure or loosening
• Bone graft-related pain
• Loss of movement at the treated level
• Stress on adjacent spinal levels
• Persistent or recurrent symptoms
• The need for additional surgery

Smoking, nicotine use, diabetes, osteoporosis, poor nutrition, and certain medications may interfere with bone healing and increase the risk of a failed fusion.

For appropriately selected patients, artificial disc replacement can provide excellent relief while preserving motion. For other patients, fusion is the safer and more durable option.

Artificial disc replacement may be favored when the patient has localized disc disease, preserved alignment, good bone quality, and healthy facet joints. Fusion may be favored when the patient needs rigid stabilization or has more advanced degeneration, instability, deformity, or poor bone quality.



The most important factor is not choosing the newest procedure. It is selecting the operation that best matches the patient’s anatomy and the specific cause of the symptoms.

Choosing between artificial disc replacement and spinal fusion requires an individualized evaluation. Imaging findings alone do not determine the best operation. Your symptoms, neurological examination, spinal alignment, stability, bone quality, activity level, and long-term goals must all be considered.

At Pinnacle Spine & Neurosurgery, we evaluate each patient carefully and discuss both surgical and nonsurgical options. When surgery is appropriate, our goal is to select the procedure that safely relieves pressure on the nerves or spinal cord while providing the best opportunity for lasting improvement.

To schedule a consultation, contact Pinnacle Spine & Neurosurgery or visit our website. We are proud to serve patients in Arkansas, with locations in Conway, Hot Springs, and Little Rock, AR. To hear from our patients, view our video testimonials.