Navigated Uniportal Endoscopic Decompression for Thoracic Myelopathy Secondary to Ossified Yellow Ligament: A Report of Two Cases

Thoracic myelopathy secondary to ossification of the yellow ligament (OYL) is uncommon but potentially disabling. Endoscopic techniques have gained attention recently as an alternative to open decompression. We report two patients who suffered from thoracic myelopathy secondary to OYL managed using a streamlined setup of navigated uniportal endoscopic decompression utilizing only a single navigated instrument. Both patients presented with bilateral lower limb numbness and instability in walking, with a modified Japanese Orthopaedic Association (mJOA) score of 13. Both cases post-operatively demonstrated complete decompression, minimal post-operative pain, short hospital stay, and neurological recovery with improvement in mJOA scores from 13 to 17 at 10 months. These cases highlighted the advantages of the combination of endoscope and navigation, which allowed easy identification of the pathological level, the ability to visualize the trajectory needed for decompression, which ensured adequacy of removal, while intraoperative CT could verify the complete decompression.