L4–L5 Degenerative Spondylolisthesis

When assessing a spondylolisthesis, the clinician should suspect an underlying pars interarticularis defect. Dynamic imaging may be beneficial to assess movement of the spondylolisthesis. This may guide management towards fusion as oppose to decompression alone. The initial management of patients presenting with axial back pain with radicular symptoms is largely conservative in the absence of neurological deficit. If the patient has persistent or progressive symptoms, surgical decompression and/or stabilization might be indicated. Patients with a symptomatic L4/L5 degenerative spondylolisthesis that are refractory to conservative management have been shown to have a beneficial treatment effect based on the SPORT trial.

Radiation-Sensitive Spine Tumor

A decision-making framework called NOMS (neurologic, oncologic, mechanical and systemic) facilitates and guides therapeutic decisions for patients with spinal metastases. Patients should be evaluated for signs of myelopathy or cauda equina syndrome. The Epidural Spinal Cord Compression (ESCC) scale facilitates reporting of the degree of radiographic spinal cord compression. A determination of the expected histology-specific tumor response to conventionally fractionated external beam radiation (cEBRT) and systemic therapy should be made. Radiation therapy effectively treats biologic pain for radiosensitive tumors such as multiple myeloma. Patients should undergo a careful evaluation of movement-associated pain as tumor-induced spinal instability is an independent indication for surgery. Determination of tumor-associated mechanical instability can be facilitated by the Spinal Instability Neoplastic Score (SINS). Herein, the authors present a case of spinal multiple myeloma managed using the NOMS framework and in consideration of current evidence and treatment paradigms.

Thoracolumbar Burst Fractures

Ten to twenty percent of all thoracolumbar spine fractures are burst fractures. Burst fractures are typically a result of an axial-loading mechanism, such as from jumping or a fall from height. In this chapter, the authors provide an overview of the different classification systems for thoracolumbar fractures, including the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification system and Thoracolumbar Injury Classification and Severity (TLICS) score. The various treatment options, both surgical and nonsurgical, are discussed, including criteria for when surgical intervention is warranted. The authors discuss the various surgical approaches for treatment of these fractures and their relative efficacies and outcomes. Finally, the authors review the evidence, outcomes, and potential complications of the various treatment options in order to aid the surgeon in their decision-making when these fractures are encountered in their practice.

Atlantoaxial Instability

There are a number of different imaging modalities that can be used to confirm atlantoaxial instability. Plain film radiographs of the cervical spine can be used to assess the atlantodental interval (ADI). Cervical CT is necessary to assess the atlantoaxial bony anatomy as well as to assess the foramen transversarium at C1 and C2. In particular, CT scan should be used to estimate screw length, medial/lateral and cranial/caudal screw trajectory. MRI can also evaluate the extent of cervical cord compression or cord injury that has occurred due to atlantoaxial instability.

Cervical Fracture Dislocation

Cervical spine fractures resulting in a dislocation often occur with a high-energy trauma. Prompt and accurate diagnosis of a fracture can be obtained with a CT scan. Controversy exists as to whether closed reduction should be performed prior to obtaining an MRI due to concerns of traumatic disc herniation. Closed reduction of a fracture with a traumatic disc herniation can potentially worsen a neurologic deficit by creating more severe cord compression. Open or closed reduction of a cervical fracture should be followed by internal fixation. Anterior, posterior, or circumferential fixation should be instituted on a case-by-case basis. Postoperative care in an intensive care unit includes maintaining adequate mean arterial pressure for spinal cord perfusion, and monitoring for signs of neurogenic shock.

Cervical Myelopathy

Patients with kyphotic deformity and degenerative cervical myelopathy are at elevated risk for traumatic and nontraumatic spinal cord injury and require comprehensive management entailing a careful clinical assessment with dedicated functional scales and radiological study of spinal balance. Surgical strategies to address this clinical scenario including anterior, posterior, and combined approaches. Whatever the choice, the surgical plan should always envisage spinal cord decompression and stabilization along with deformity correction. The surgical team should discuss pros and cons of the most appropriate surgical plan with the patient, anticipate possible complications, and propose alternate strategies. This chapter details the most important practical aspects of surgical management, ranging from technical advantages of multiple osteotomies and selection of implants for instrumented fusion, to the surgical and anesthesiological nuances to avoid intraoperative and postoperative complications. An overview is provided of scientific literature regarding the correction of kyphotic deformity and ongoing clinical trials.

Epidural Abscess

There are several conditions that have similar symptoms as those seen in spine infections so it is important to apply imaging studies, labs, and patient history in the workup. In the case of a true spinal epidural abscess (SEA) there exists a tetrad of stages, as described by Heusner et al. These can be characterized with a spinal ache or pain that proceeds into the second stage of nerve root pain, which is followed by the third stage of weakness in the voluntary muscles that culminates at the fourth stage of paralysis. Due to the danger of rapid progression, most spinal epidural abscesses are considered to be a neurosurgical emergency.

Diskitis

Spinal osteomyelitis/diskitis is a common problem encountered by neurosurgeons and requires urgent workup. Common risk factors include intravenous drug use or immunocompromised states. The presence or absence of neurologic deficit is critical in determining the treatment algorithm. Magnetic resonance imaging is the preferred imaging modality to diagnose osteomyelitis/diskitis, as well to identify concomitant epidural abscess. Inflammatory markers such as erythrocyte sedimentation rate and c-reactive protein can also be useful in diagnosis. Gram-positive organisms such as Staphylococcus aureus are the most common pathogens. Surgical indications include neurologic deficit, progressive deformity, recalcitrant pain, and inability to clear systemic infection without other source. Surgical goals are typically to decompress the neural elements, debride the infected disc or bone, and stabilize the spine if necessary.

Lumbar Stenosis

Low back pain is an extremely frequent outpatient complaint across all fields of medicine. Among its surgical causes, lumbar stenosis is one of the most commonly seen in the neurosurgeon’s clinic. In this chapter, the authors present a case of a patient with classic symptoms of neurogenic claudication who is found to have multilevel degenerative lumbar stenosis on imaging. The authors discuss the evaluation of such patients by examination and imaging, with attention given to important alternatives in the differential diagnosis. They describe the surgical management of lumbar stenosis by conventional open decompression as well as newer minimally invasive techniques. Finally, the authors discuss key aspects of postoperative and complication management.

Cauda Equina Syndrome

Cauda equine syndrome arises secondary to compression of or injury to the cauda equine, a group of nerves in the lumbosacral spine that provide motor and sensory function to most of the lower extremities, pelvic floor musculature, and sphincters. Symptoms can include loss of bowel and bladder control, lower extremity motor and sensory deficits, and pain. Compressive etiologies such as a midline herniated disc are the most common cause of cauda equine syndrome. Any patient with the described constellation of symptoms should undergo magnetic resonance imaging of the lumbar spine. In the setting of acute loss of motor, sensory, or autonomic function and a disc herniation or other compressive lesion seen on a lumbar spine MRI, emergency decompression via laminectomy should be undertaken. Complications range from structural damage intraoperatively to more general postsurgical complications. Operating on cauda equine patients at the earliest opportunity seems the most appropriate clinical practice.