Cervical Myelopathy Secondary to Combined Ossification of Ligamentum Flavum and Posterior Longitudinal Ligament-A Case Report.

In the cervical spine, the combined ossification of the ligamentum flavum (OLF) and posterior longitudinal ligament is rarely seen. Patients are usually treated with cervical laminectomy or laminoplasty with OLF resection. In most of the cases, OLF is adhered to the dura and there is a risk of dural tear or cerebrospinal fluid (CSF) leakage during its resection. In this case report, the authors present results of laminectomy with debulking instead of complete excision of OLF for spinal cord decompression in a cervical myelopathy case in which OLF was adhered to the dura. A 69-year-old man presented with insidious onset weakness in bilateral lower limbs and unsteady gait, which he had experienced 1 month. He has a history of neck pain with left upper limb radiation for the last 2 years. Magnetic resonance imaging showed C5-6 severe central canal stenosis with underlying myelomalacia. Computed tomography showed ossification posterior longitudinal ligament and OLF contributing to severe central canal stenosis at the C5-6 level. The patient underwent C4-C6 laminectomy, debulking of OLF, posterior instrumentation, and fusion with autogenous bone graft from C3 to C6. A histological specimen showed osseous tissue within the ligamentum flavum. After surgery the patient's symptoms improved and no recurrence was observed at 4 years after surgery. The symptoms of myelopathy were successfully treated with debulking instead of complete excision of OLF, thus reducing the risk of dural tear or CSF leakage.