Cervical Pannus Without Rheumatoid Arthritis or Trauma

Cervical pannus is a disease that could easily develop in an active-duty soldier or veteran. The disease has been associated with trauma and rheumatoid arthritis, or can be idiopathic. For years, cervical pannus has been closely tied to rheumatoid arthritis; however, a study published in 2019 showed that only 28% of patients with cervical pannus had an associated diagnosis of rheumatoid arthritis.¹ In the same study, 18% of patients had undergone some type of prior cervical spine surgery as the next most common cause. The condition also can occur years after an injury.

Background

In the US, 42,000 veterans are living with spinal cord disease, and thousands of these veterans have surgery every year.² Service men and women and veterans are at risk for cervical pannus as they age especially if they have a history of rheumatoid arthritis, cervical spine surgery, trauma, and numerous other causes. It is critical for health care providers who treat this population to understand cervical pannus, how to recognize it, and how to identify patients at risk. A cervical pannus can be life threatening if not detected and treated properly.

There is no clear definition for cervical pannus. Some researchers think of it as the chronically inflamed synovial membrane in patients with rheumatoid arthritis (RA); others consider it as a specialized synovial membrane derived from vascular soft tissue structures at or near the bone synovial membrane.³ The pathogenesis for developing a pannus is not well understood, and little is known when a pannus begins or its initial location. A pannus formation can occur in any synovial joint in the body, such as wrists, metacarpophalangeal joint, proximal interphalangeal joint, and cervical joints.

A cervical pannus can cause serious complications. It can lead to a cervical subluxation in up to 4% of patients with RA, or it also can occur spontaneously in some patients without RA especially those with trauma or cancer.⁴

There are 2 suggested mechanisms by which the synovial membrane proliferates. It was originally believed that T cells from the chronic inflamed joint lead to the pannus formation by initiating an autoimmune reaction through the production of different cytokines against arthritogenic agents.^3-5 These cytokines increase inflammation by recruiting neutrophils and activating various kinds of macrophages that might lead to increased osteoclast activity.⁶ Osteoclastic activity can damage bone and allow the synovium to penetrate the bone, forming the pannus.

Another proposed mechanism is that the synovial cells hyperpolarize and hypertrophy automatically without T-cell help by expressing oncogenes and their proteins.³ In either case, angiogenesis follows this proliferation and increases the influx of inflammatory cells into the joints, which can lead to more destruction.⁷ This increase in blood supply to the synovial membrane is important in the growth of the pannus and can have a damaging effect to cartilage, bone, and joints.^4,7

Cervical pannus can progress in patients with prolonged use of corticosteroids.⁸ Because a pannus can put pressure on any segment of the cervical spine and the cranio-cervical junction leading to cervical instability, patients with this condition may present with a variety of clinical symptoms.⁹ The most frequently reported clinical features include neck pain, easy fatigability, difficulty walking, abnormal gait, increased clumsiness, and numbness and tingling in the arms. Patients also may complain of neck stiffness and decreased neck motion.¹⁰Cervical pannus is most frequently seen in patients with RA. However, patients without a RA diagnosis and incidental atlantoaxial pannus on cervical spine magnetic resonance imaging (MRI) are unlikely to have previously undiagnosed RA.¹¹