Proximal Vertebral Body Fracture after 4-Level Fusion Using L1 as the Upper Instrumented Vertebra for Lumbar Degenerative Disease: Report of 2 Cases with Literature Review

Some cases with lumbar degenerative diseases require multi-level fusion surgeries. At our institute, 27 and 4 procedures of 3- and 4-level fusion were performed out of a total 672 posterior lumbar interfusions (PLIFs) on patients with lumbar degenerative disease from 2005 to 2010. We present 2 osteoporotic patients who developed proximal vertebral body fracture after 4-level fusion. Both cases presented with gait disability for leg pain by degenerative lumbar scoliosis and canal stenosis at the levels of L1/2-4/5. After 4-level fusion using L1 as the upper instrumented vertebra, proximal vertebral body fractures were found along with the right pedicle fractures of L1 in both cases. One of these patients, aged 82 years, was treated as an outpatient using a hard corset for 24 months, but the fractures were exacerbated over time. In the other patient, posterolateral fusion was extended from Th10 to L5. Both patients can walk alone and have been thoroughly followed up. In both cases, the fracture of the right L1 pedicle might be related to the subsequent fractures and fusion failure. In consideration of multi-level fusion, L1 should be avoided as an upper instrumented vertebra to prevent junctional kyphosis, especially in cases with osteoporosis and flat back posture

Arteriovenous Fistula at the Craniocervical Junction Found After Cervical Laminoplasty for Ossification of the Posterior Longitudinal Ligament

Ossification of the posterior longitudinal ligament (OPLL) is common in East Asia. Arteriovenous fistula at the craniocervical junction (CCJ-AVF), in contrast, is rare. As OPLL occurs most often in the cervical region, these 2 conditions can coexist in the cervical spinal canal of a single patient. We report a case of CCJ-AVF found after cervical laminoplasty (CLP) for OPLL. A 68-year-old man experienced progressive myelopathy due to cervical OPLL. Magnetic resonance imaging (MRI) revealed a high-intensity area inside the spinal cord. CLP was performed and his symptoms immediately improved. Three months after CLP, however, myelopathy recurred. MRI revealed an exacerbated and enlarged high-intensity area inside the cord from the medulla oblongata to the C4/5 level with a flow void around the cord. Left vertebral artery angiography revealed CCJ-AVF with ascending and descending draining veins. Direct surgery was performed to interrupt shunt flow into the draining veins. The patient’s symptoms improved to a limited degree. In this case, increased pressure inside the spinal canal due to OPLL might have decreased the shunt flow of the CCJ-AVF. Thus, the venous congestion induced by CCJ-AVF might have been exacerbated after the pressure was removed by CLP. Magnetic resonance angiography screening could help detect concurrent CCJ-AVF and OPLL