Achieving solid osseous fusion across the lumbosacral junction has historically been, and continues to be, a challenge in spine surgery. Robust pelvic fixation plays an integral role in achieving this goal. The goals of this review are to describe the history of and indications for spinopelvic fixation, examine conventional spinopelvic fixation techniques, and review the newer S2-alar-iliac technique and its outcomes in adult and pediatric patients with spinal deformity. Since the introduction of Harrington rods in the 1960s, spinal instrumentation has evolved substantially. Indications for spinopelvic fixation as a means to achieve lumbosacral arthrodesis include a long arthrodesis (five or more vertebral levels) or use of three-column osteotomies in the lower thoracic or lumbar spine, surgical treatment of high-grade spondylolisthesis, and correction of lumbar deformity and pelvic obliquity. A variety of techniques have been described over the years, including Galveston iliac rods, Jackson intrasacral rods, the Kostuik transiliac bar, iliac screws, and S2-alar-iliac screws. Modern iliac screws and S2-alar-iliac screws are associated with relatively low rates of pseudarthrosis. S2-alar-iliac screws have the advantages of less implant prominence and inline placement with proximal spinal anchors. Collectively, these techniques provide powerful methods for obtaining control of the pelvis in facilitating lumbosacral arthrodesis.

Familiarity with the history of neuromonitoring in spinal deformity surgery and an understanding of the physiological systems used for neuromonitoring provide a framework from which spine surgeons can select appropriate monitoring for their patients.

» Most tumors of the hand and the wrist are benign; however, malignant conditions can mimic benign tumors and must be worked up accordingly.» Advanced imaging should be followed by biopsy before definitive treatment of tumors of unknown diagnosis.» The most common soft-tissue masses in the hand and the wrist are ganglion cysts, whereas the most common bone tumors are enchondromas.

Nerve tumors of the upper extremity include benign peripheral nerve sheath tumors (BPNSTs) and malignant peripheral nerve sheath tumors (MPNSTs). The most common peripheral nerve sheath tumors (PNSTs) of the hand and upper extremity are schwannomas, which are benign tumors of Schwann cell origin 1-4 (Fig. 1). Multiple schwannomas may occur in schwannomatosis. Neurofibromas, also benign, are classically associated with neurofibromatosis (NF) but can occur as solitary lesions. These tumors also may be associated with gigantism of the underlying anatomy. 1 BPNSTs can be observed or surgically excised with careful microscopic intrafascicular dissection. 4 BPNSTs can transform to MPNSTs, which require more aggressive surgical treatment by a multidisciplinary team. Clinical and radiological factors for identifying malignant tumors and differentiating these from their benign counterparts are discussed. The most current recommended surgical techniques for tumor excision also are reviewed. CONTENT Clinical Presentation Classic symptoms of malignant degeneration of an MPNST include rapid growth, pain at night, size greater than 5 cm, previously soft consistency that becomes firm, and any associated constitutional symptoms. 5 Malignant transformation is rare for schwannomas. 1 Neurofibromas associated with NF are more likely to undergo malignant transformation than solitary lesions. 1,2 MPNSTs may occur in 2% to 13% of patients with NF1 compared with 0.001% of the general population 5,6 ; 50% of MPNSTs are in patients with NF1 but can occur postradiation or sporadically. 7,8 Rapid growth of a plexiform neurofibroma in NF1 may not necessarily represent malignant transformation. This is a Disclosure Statement: The authors have nothing to disclose.