I had a disc replaced in my neck at C56 and was expecting to have better motion after recovery. I do have relief from my pain but my neck is still so stiff. Any ideas why that is and what I can do about it?

Many studies have been done looking at neck motion before and after neck surgery. Disc degeneration is the usual reason why artificial disc replacement is considered. Before disc replacements became available, patients had one option: fusion.

With a cervical spine fusion, loss of motion is a certainty. In fact,that is the goal of fusion: to stabilize a segment that is diseased or damaged. Now, with artificial disc replacements, motion can be preserved. The damaged disc is removed and an artificial device is implanted in its place.

But not all units are the same. Some are made of stiffer materials. Each has its own working mechanical parts and biomechanical properties. These are factors that can affect results in terms of neck motion and stiffness.

Surgeons have also found that patients with severe disc collapse before surgery are more likely to have stiff, contracted (stuck) spinal ligaments and facet capsules. Facet capsules refers to the fibrous material around the spinal joints. When the capsule ages, dries out, and gets stiff, replacing the disc will help the vertebral segment move. But without a normal facet (spinal) joint, full motion still isn’t available.

There are a lot of other potential factors. Getting the right size of disc device and having it placed at the best angle and the correct depth are all important in neck motion postoperatively. An artificial disc that’s too big for you or too far forward can contribute to reduced motion and subsequent stiffness.

If you haven’t mentioned this to your surgeon, it might be a good idea to go in for a follow-up appointment. It’s possible there are issues with posture, muscle flexibility, motor control of the muscles, and proprioceptive (joint position awareness) that could be helped with intervention from a physical therapist.