A Case of Foraminal Disc Herniation Successfully Treated via Paraspinal Transpars Approach

A 61-year-old man presented with an excruciating pain in the right lower extremity. The pain was aggravated by a short distance walk and lateral bending to the right. These symptoms implied right L4 radicular pain. Magnetic resonance images revealed foraminal disc herniation at the right L4-5 level. After failure of conservative treatment, the patient underwent surgery via the paraspinal transpars approach. Following exposure of the right lateral edge of the L4 lamina, we partially resected a part of the pars interarticularis in accordance with the preoperative simulation using a 3-dimensional printed bone model. Fragmented discs compressing the dorsal root ganglion of L4 nerve root were totally removed. Postoperative computed tomography showed complete preservation of the facet. The patient showed remarkable relief from the pain and returned to his job a week after the surgery. Foraminal disc herniations cause fierce leg pain and are often intractable to conservative treatment. Selection of the surgical approach is often a matter of debate. The paraspinal transpars approach was effective and a less invasive surgical method in that it can preserve the facet joint. A three-dimensional printed bone model was useful in determining the minimal resection range of the pars interarticularis.