Anterior Decompression Through Posterior Approach for Thoracic Myelopathy Caused by OPLL: Ohtsuka Procedure

Abstract

The incidence of ossifi cation of the posterior longitudinal ligament (OPLL) in the thoracic spine is lower than that of cervical myelopathy caused by cervical OPLL. However, once compressive myelopathy appears at the thoracic spine, which is mechanically more stable than other spinal levels by nature, conservative treatment such as rest or immobilization by brace is considered ineffective [1–3]. Accordingly, decompression surgery is usually recommended for patients with severe or moderate thoracic myelopathy caused by OPLL. For thoracic myelopathy due to OPLL, it has been pointed out that the results of posterior decompression are uncertain or even poor in many patients [4,5]. The main reason for these poor results is that the thoracic spine is naturally kyphotic, and the spinal cord is compressed anteriorly. At the present time, choices of treatment for thoracic OPLL consist of anterior decompression through the anterior or posterior approach, posterior extensive laminectomy, and circumferential anterior and posterior decompression [6–13]. The choice of a surgical decompression procedure is still controversial among surgeons. In general, for patients with spinal cord compression caused by OPLL at the kyphotic portion of the thoracic spine, anterior decompression is recommended. However, for some patients with mild kyphosis at the thoracic spine, a simple, less invasive posterior extensive laminectomy may be indicated for decompression of the OPLL [4,6]. In this chapter, we focus on the indications, surgical technique, and results of anterior decompression through the posterior approach for thoracic myelopathy caused by OPLL. Indications for Surgery