https://www.selleckchem.com/products/jhu395.html In zone IV, type IV was the most frequent LA type at L3 (n=44; 88.0%), L4 (n=42; 93.3%), and L5 (n=6; 100%). CONCLUSIONS The risk of LA injury during OLIF is the least when the cage is placed in zones II and III. Care is required during OLIF in zone IV of L3-L5. The fixation pin should be fixed on the upper edge of the lower vertebral body at L1-L2 and L2-L3, and on the lower edge of the upper vertebral body at L3-L4 and L4-L5. BACKGROUND Osteoblastomas are rare primary bone tumors with a predilection for the spine. The extraosseous growth pattern is rare to our knowledge, only two cases of fully extraosseous osteoblastomas have been previously reported. CASE DESCRIPTION A 36-year-old man presented with a 7-month history of low back pain radiating to the gluteal area. On examination, a typical L5 radiculopathy was noted. The radiological examinations conducted in the previous months pointed out the rapid growth of an extraosseous mass occluding the right L5-S1 foramen. Partial laminectomy was performed in order to achieve gross total resection. Histological analysis was consistent with osteoblastoma. CONCLUSIONS Osteoblastomas with extraosseous extension are uncommon, and an exclusively extraosseous presentation is anecdotal. This can lead to preoperative misdiagnosis when typical radiological characteristics of bone-forming tumors are missing. We describe the case of an extraosseous lumbar osteoblastoma whose clinical and radiological presentation was suggestive of malignancy. BACKGROUND Patients with single-suture or minor suture craniosynostosis are typically asymptomatic at early presentation; intervention is aimed at reducing the risk of elevated intracranial pressure and associated developmental sequelae. Patients may be symptomatic in cases of major multi-suture syndromic synostoses or delayed diagnosis. Clinical presentation in this context may include headaches, papilledema, cognitive delay, or behavioral iss