Surgical method for cervical myelopathy caused by ossification of posterior longitudinal ligament depends on cervical sagittal alignment and shape of ossification mass. For K-line (-) patients, indirect decompression method such as laminoplasty may not be effective since posterior shift of spinal cord would not occur. Therefore, other surgical method is frequently needed in this patient group. In this article, we would review surgical methods that could be applied for patients with K-line (-) cervical myelopathy caused by ossification of posterior longitudinal ligament.

Cervical ossification of posterior longitudinal ligament (OPLL) can cause cord compression which can lead to myelopathy. Operative management including anterior fusion or laminoplasty is needed in these cases. Understanding the progression course of OPLL, risk factors of progression, and risk factors of myelopathy caused by OPLL is essential to determine the necessity, timing and method of operation. Therefore, we will review the previous study results regarding characteristics and progression course of OPLL. Furthermore, the results of study about risk factors and progression course of OPLL undergoing conservative management will be discussed.

Fifty-six-year old male patient visited our institution for low back pain for 2 months. The clinician of surgical department diagnosed as abscess or lymphocele on the basis of the findings of abdomen CT and lumbar MRI. The patient visited department of orthopaedic surgery after 6 months later from initial symptom. The back mass was grown larger on the CT and MRI. High grade pleomorphic sarcoma (malignant fibrous histiocytoma) was confirmed by aspiration biopsy. We performed massive excision of the mass with adjuvant chemotherapy and radiotherapy. No recurrence has been found during 1-year follow-up. Malignant fibrous histiocytoma can be mistaken for simple cyst or abscess on its early stage and can bring about bad prognosis because it grows rapidly. If the margin of the cystic lesion is irregular or thick, and the clinical findings are is not suitable for infection, malignant tumor should be suspected.