Cervical Spine Pseudogout Mimicking Ossification of the Posterior Longitudinal Ligament: A Case Report and Literature Review.

Calcium pyrophosphate deposition (CPPD) disease, commonly known as pseudogout, is characterized by calcium pyrophosphate crystal accumulation in joint tissues. While CPPD typically affects peripheral joints, cervical spine involvement is rare but significant due to potential spinal cord and nerve root compression, leading to myelopathy and radiculopathy. Here, we describe a 69-year-old female who presented with progressive cervical myelopathy and extensive calcifications in the cervical ligamentum flavum (CLF), posterior longitudinal ligament (PLL), and intervertebral discs. These findings initially resembled ossification of the posterior longitudinal ligament (OPLL), a much more prevalent pathology. Surgical decompression through both anterior and posterior approaches relieved the compression. Pathological evaluation confirmed CPPD via the identification of weakly positive birefringent crystals. Postoperatively, the patient's symptoms improved significantly, although persistent right shoulder pain suggested CPPD in peripheral joints. This report underscores the rarity of cervical CPPD with widespread ligament and disc involvement, emphasizing that it can mimic common degenerative diseases like OPLL. Early recognition and surgical intervention are imperative for preventing irreversible spinal cord damage and achieving favorable outcomes. In addition, the persistent right shoulder pain illustrates that CPPD can occur at multiple sites and requires a holistic approach to patient care.