Introduction:
Rheumatoid arthritis (RA) is a chronic autoimmune connective tissue disease characterized by symmetrical arthritis associated with extra-articular changes. Although peripheral joint involvement is the dominant symptom of RA, many patients develop cervical spine involvement in the course of the disease, manifesting as cervical instability.

Aim:
The aim of this study is to describe a case of an RA patient with spinal myelopathy to increase awareness of this complication, hoping that its early diagnosis may prevent further serious consequences.

Case study:
A 63-year-old patient, who was diagnosed with RA 18 years ago, was admitted to the Rheumatology Clinic due to suspected exacerbation of rheumatic disease. Functional X-Ray and MRI was performed, which showed instability in the C3–C4 segment with spinal cord compression. Subsequently, the patient underwent cervical spine surgery. After the surgery and rehabilitation, the patient demonstrated neurological improvement.

Results and discussion:
Every patient diagnosed with RA should be educated about the possibility of a complication of cervical instability and be familiar with the neurological symptoms that may result from it. If cervical instability and subsequent cervical myelopathy are detected early, the symptoms may be reversible or significantly reduced by surgical spinal cord decompression and cervical stabilization.

Conclusions:
It is very important to perform a functional X-ray of the cervical spine to exclude instability, especially before rehabilitation treatment. Neck pain in patients diagnosed with RA may indicate cervical instability that requires more thorough neurological examination to exclude cervical myelopathy.