Cervical fusion is a surgical procedure designed to stabilize the cervical spine. The surgery involves permanently joining two or more adjacent vertebrae to create a single, solid bone mass, a healing process technically known as arthrodesis. By eliminating movement at a damaged segment, the procedure aims to alleviate chronic pain, weakness, and nerve compression caused by instability or degeneration. Patients frequently wonder about the extent to which this stabilization will affect their future ability to move their neck.
Immediate Post-Surgical Immobilization
The initial phase following cervical fusion, typically lasting between six and twelve weeks, is dedicated to achieving a successful bony fusion. The primary objective during this period is to strictly immobilize the neck to allow the bone graft and surrounding tissues to heal. Surgical hardware, such as plates, screws, and rods, acts as an internal brace to stabilize the segments, but external support is often still necessary.
Surgeons may prescribe an external cervical collar, ranging from a soft foam support to a rigid orthosis like the Philadelphia or Miami J collar. The type of collar chosen depends on the complexity of the fusion, the number of levels involved, and the quality of the patient’s bone. While a soft collar primarily serves as a reminder to limit movement, rigid collars can restrict approximately 63% of the total range of motion.
Despite wearing a collar, patients must avoid all major movements, including extreme flexion, extension, and rotation. These movements can introduce micromotion at the surgical site, which is the leading cause of non-union, where the bones fail to fuse. Once the surgeon confirms initial bone healing, the focus shifts from rigid restriction to gradual movement.
Long-Term Range of Motion
Once the fusion is complete, the movement capabilities of the neck enter a permanent, altered state. The fused spinal segments will no longer contribute to overall mobility, meaning the loss of motion at those specific levels is absolute. However, the total impact on neck movement is often less profound than anticipated, due to the unique biomechanics of the cervical spine.
The greatest amount of head rotation occurs high up in the neck, specifically at the atlantoaxial joint (C1-C2). This single joint is responsible for an estimated 50% to 73% of total cervical rotation. Since most cervical fusions target the lower segments (C3 through C7) to treat degenerative disc disease, rotation is typically the least affected plane of motion.
Movements in the sagittal plane, such as flexion and extension, are more evenly distributed across the mid-to-lower cervical spine. Each unfused segment contributes to the remaining range of motion. A single-level fusion, such as C5-C6, may only result in a subtle loss of 4.4% to 7.2% of the overall neck range of motion, which is often unnoticeable in daily life.
In contrast, a multi-level fusion involving three or four segments, such as C3-C7, results in a more significant reduction in movement. Patients with multi-level fusions may experience a loss of over 25% in overall flexion, extension, and lateral bending, and a roughly 14% loss of rotation. The unfused segments above and below the surgical site will naturally increase their range of motion in a compensatory effort to maintain functional mobility.
Adaptation and Rehabilitation Strategies
The final phase of recovery focuses on maximizing a patient’s functional movement within their new physical limitations. After receiving clearance from the surgeon, physical therapy plays a significant role in helping the patient adapt to the permanent changes. The therapist will focus on strengthening the muscles surrounding the fused area, particularly the shoulders, upper back, and deep neck flexors, to provide support and stability.
A primary goal of rehabilitation is teaching compensatory movement patterns to make up for the restricted neck motion. For instance, when attempting to look sideways, a patient learns to pivot their entire torso and shoulders rather than relying solely on the neck. When getting out of bed, patients are taught the “log-roll” or “trunk block” technique, which involves moving the head, neck, and torso as one unit to protect the spine.
Daily activities that require a large range of neck motion, such as checking a blind spot while driving, require practical modifications. Patients are advised to adjust their car mirrors to maximize visibility and rely more on backup cameras and blind spot monitors. For tasks like reading or working at a computer, postural reeducation emphasizes keeping the head in a neutral, supported position to prevent strain on the adjacent, unfused segments.