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Both PEEK cages and FCAs are highly effective in promoting interbody fusion, maintaining postoperative disc space height, and achieving desirable clinical outcomes in patients who undergo TLIF with pedicle screw fixation. The advantages of PEEK cages include a lower incidence of subsidence and their radiolucency, which permits easier visualization of bone growth.

We have determined whether the nitroxide antioxidant, tempol, can oppose tissue loss and improve recovery of locomotor function following contusion injury of the spinal cord. Contusion injury was produced in rats at the level of T10 with a weight-drop device and locomotor recovery was determined with the 21-point Basso, Beattie and Bresnahan (BBB) scale. Locomotor function recovered progressively during the 6-week postinjury observation period and was significantly greater in tempol-treated (275 mg/kg i.p., 20 min postinjury) compared to vehicle-treated rats (final BBB scores: 9.1 versus 6.4). Similarly enhanced locomotor recovery was observed with doses of tempol in the range of 138-550, but not 69 mg/kg, and with injection at 48 h postinjury indicating a therapeutic time-window of at least several days. The extent of recovery correlated with measurements of sparing of spinal cord white matter in a region several millimeters in length extending rostrally from the contusion epicenter. In contrast, loss of gray matter was unaffected by tempol treatment. Since tempol acts by scavenging reactive oxygen species (ROS) such as superoxide and hydroxyl radicals, the improved locomotor recovery and spared spinal cord tissue following contusion injury provides evidence of a direct role of ROS-mediated neurodegeneration in spinal cord injury.

In the past several decades methods have been developed to stabilize the subaxial cervical spine both posteriorly and anteriorly. Methods of posterior stabilization have progressed from interspinous wiring, through facet wiring and sublaminar wiring, to the lateral mass screws with plates and rods that are in use today. Plates for anterior stabilization have evolved from rigid plates requiring bicortical screws through those used with unicortical locking screws, to dynamic load-sharing plates used with variable angle screws. The original description of spinous process wiring was published by Hadra in 1891. In 1942 Rogers described the interspinous wiring method used for trauma-induced cervical instability, which was modified by Bohlman in 1985 (triple wiring technique). Luque rods with sublaminar wires were introduced in the late 1970s to address multilevel and occipitocervical instability. Facet wiring was developed in 1977 by Callahan to address the problem of stabilization when laminae are not present. Wiring remained the method used until Roy-Camille introduced the lateral mass screw–plate construct in the 1980s. The first plate for anterior stabilization was designed by Orozco and Llovet in 1970 and was later refined by Caspar; this was a rigid plate with bicortical screws. Morscher devised unicortical locking screws in the 1980s. The latest concept of dynamic load-sharing plates with variable angle screws was developed in 2000. In this article historical landmarks in surgical methods for the stabilization of the subaxial cervical spine are reviewed.

Object An iliac crest autograft is the gold standard for bone grafting in posterior atlantoaxial arthrodesis but can be associated with significant donor-site morbidity. Conversely, an allograft has historically performed suboptimally for atlantoaxial arthrodesis as an onlay graft. The authors have modified a bone grafting technique to allow placement of a bicortical iliac crest allograft in an interpositional manner, and they evaluated it as an alternative to an autograft in posterior atlantoaxial arthrodesis. Methods The records of 89 consecutive patients in whom C1–2 arthrodesis was performed between 2001 and 2005 were reviewed. Results Forty-seven patients underwent 48 atlantoaxial arthrodeses with an allograft (mean follow-up 16.1 months, range 0–49 months), and 42 patients underwent autograft bone grafting (mean follow-up 17.6 months, range 0–61.0 months). The operative time was 50 minutes shorter in the allograft (mean 184 minutes, range 106–328 minutes) than in the autograft procedure (mean 234 minutes, range 154–358 minutes), and the estimated blood loss was 50% lower in the allograft group than in the autograft group (mean 103 ml [range 30–200 ml] vs mean 206 ml [range 50–400 ml], respectively). Bone incorporation was initially slower in the allograft than in the autograft group but equalized by 12 months postprocedure. The respective fusion rates after 24 months were 96.7 and 88.9% for autografts and allografts. Complications at the donor site occurred in 16.7% of the autograft patients, including 1 pelvic fracture, 1 retained sponge, 1 infection, 2 hernias requiring repair, 2 hematomas, and persistent pain. Conclusions The authors describe a technique for interpositional bone grafting between C-1 and C-2 that allows for the use of an allograft with excellent fusion results. This technique reduced the operative time and blood loss and eliminated donor-site morbidity.

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Spinal cord involvement by perineural spread of malignant mesothelioma is rare. We report a case of malignant mesothelioma that spread locally to invade the bony spine with both extradural and intradural perineural spread into the spinal canal that resulted in spinal cord compression. A 61-year-old man with a history of malignant mesothelioma presented with progressive leg weakness and right-sided arm weakness. Magnetic resonance imaging showed an enhancing lesion in the apex of the right lung with extension through the C7-T1 foramina with right hemicord enhancement. The patient underwent a C7-T1 laminectomy and right-sided C7-T1 and T1-T2 foraminotomies for neural decompression and biopsy of the lesion. Intraoperatively, tumor extended epidurally, and intradural perineural tumor spread along the C8 and T1 nerve roots into the spinal cord. Because it adhered to the spinal cord, no dissectible plane could be identified that would allow for safe total removal of the tumor. The epidural portion of the tumor, the adjacent involved bone, and the T1 nerve root were resected. Pathologic examination revealed malignant mesothelioma with bony invasion and perineural spread along the T1 nerve root. After decompression of the spinal cord, the patient had moderate improvement of his hand and leg function. Perineural spread of malignant mesothelioma resulting in spinal cord compression is an unusual clinical presentation. Intimate involvement of the spinal cord may prohibit aggressive tumor resection.

Extramedullary hematopoiesis (EMH) is a rare cause of spinal cord compression (SCC). EMH represents the growth of blood cells outside of the bone marrow and occurs in a variety of hematologic illnesses, including various types of anemia and myeloproliferative disorders. Although EMH usually occurs in the liver, spleen, and lymph nodes, it may also occur within the spinal canal. When this occurs, the mass effect can compress the spinal cord, potentially leading to the development of neurological deficits. We present a case of SCC secondary to EMH. This report illustrates the importance of considering EMH in the differential diagnosis of SCC, even in the absence of signs of its most common etiologies.