Cervical Spine Myelopathy Caused by Calcium Pyrophosphate Dihydrate Deposition of the Ligamentum Flavum: A Case Report.

Calcium pyrophosphate dihydrate deposition (CPPD), commonly known as pseudogout, is an inflammatory arthropathy primarily affecting the knee, wrist, hip, and shoulder joints. However, it can occasionally deposit in various structures surrounding the spinal column, including the facet joints, ligamentum flavum, bursae, and intervertebral discs. Such occurrences are typically asymptomatic or associated with mild neck pain. Nonetheless, severe cases may lead to myeloradiculopathy, characterized by severe neck pain and upper extremity weakness. Conservative management with nonsteroidal anti-inflammatory drugs is often sufficient for mild cases, while surgical decompression remains the gold standard for severe cases with significant spinal cord compression. Herein, we present a rare case of pseudogout, manifesting as cervical spine myelopathy due to calcium pyrophosphate dihydrate deposition in the ligamentum flavum and facet joints at C1-2. This was found incidentally during cervical spine decompression and fusion and subsequentially confirmed through pathological examination. Following the removal of the compressive pathology, the patient reported significant improvements in neck pain and neurological symptoms. This case underscores the importance of considering pseudogout in the differential diagnosis of acute neck pain presenting with myelopathy or radiculopathy.