Self Assessment Examination Adult S Review | Dr Hutaif - ...

■
The patient has sustained a herniated disk, which is likely causing his radicular symptoms. The patient does not have significant weakness or myelopathic symptoms, and initial treatment should be nonoperative. However, Hsu found that surgical treatment is shown to result in a better chance of returning to play in National Football League players. Regardless the treatment, the patient should not be allowed to return to play until he is asymptomatic with normal range of motion and a negative neurological examination.

■
Studies report a radiographic heterotopic ossification (HO) rate of >40% after long-term follow-up of cervical disk replacements. Therefore, cervical disk replacements do carry a significant rate of HO development. However, the clinical significance is difficult to determine, as most of those patients are not symptomatic. Long-term studies show a lower revision rate and lower radiographic adjacent segment degeneration with two-level cervical disk replacement compared with two-level ACDF. However, both treatment options are considered effective procedures for the treatment of cervical radiculopathy at two adjacent
levels.

■
Any progressive neurologic deficit requires emergent surgical intervention. Lumbar injuries cannot be reliably reduced with traction. Although IV steroids and management of mean arterial blood pressure are appropriate interventions for injuries in the region of the conus medullaris, steroids are only indicated when given within 8 hours of injury and are not appropriate as a sole means of management for progressive neurologic deficit.

■
The MIS approach to the L4-L5 level places the lumbar nerve roots at the highest risk of injury during surgery. The psoas muscle and lumbar nerve roots course more anteriorly as they move caudally from L1 toward L5. Intraoperative neuromonitoring is considered standard in these procedures, especially at the L4-L5 to reduce the risk of iatrogenic nerve injury.

■
The MRI cervical spine scan reveals a C4-C5 traumatic anterolisthesis with severe spinal stenosis. There is evidence of spinal cord swelling and myelomalacia at this level. A physical examination is provided. The ASIA scale provides grading of severity of a spinal cord injury.
The grading incorporates strength and motor function based on the spinal level.
ASIA A is a complete spinal cord injury with no motor or sensory function. ASIA B is an incomplete spinal cord injury with no motor function below the spinal level of injury and sacral sparing of sensation. ASIA C is an incomplete spinal cord injury with motor function <3 of 5 in more than half of the muscles below the spinal level of injury. ASIA D is an incomplete spinal cord injury with motor function >3 of 5 in at least half of the muscles below the spinal level of injury. ASIA E is normal sensation and motor function.

■
The use of IV antibiotics for prophylaxis of surgical-site infection is supported by Level 1 evidence in spine surgery. It has been given a "B" recommendation by the North American Spine Society. The use of specific bathing solutions the day of surgery may be beneficial, but the evidence in spine surgery is lacking. Similarly, evidence for use of vancomycin (either topically or IV) is not supported by high-level studies, although retrospective and basic science studies support topical vancomycin use.

■
The images reveal a severe burst fracture of L2 with significant middle column bony retropulsion into the spinal canal. Although additional tests may be required in specific spinal injuries, a rectal examination is a required part of the spinal injury examination. An L2 burst fracture can cause injury to the spinal cord at the conus medullaris, which normally terminates at L1-L2. Typically, such injuries are a mixed cauda equina nerve root injury with a spinal cord injury of the conus medullaris. In this case, the patient fell onto his buttocks without hitting his head thus, not requiring a head CT. He is able to walk and does not complain of foot pain.

■
The patient is asymptomatic from the sacral lesion, but has a history of a malignant lesion, so the suspicion is high that the sacral lesion is a recurrence or a metastatic lesion. The radiograph and CT scans show a lytic lesion within the osseous margins of the sacrum, and the histologic section shows no malignant cells. The diagnosis is Paget's disease, which is typically treated medically. Bisphosphonate treatment is typical, but is currently controversial as to whether it helps more than just controlling the local symptoms. Radiographic features vary but can reveal cortical thickening, coarse trabeculae, and sclerotic or enlarged vertebral bodies. The sacrum is typically involved. Histologically there is "mosaic" appearing bone with numerous random intersecting lines, overly active osteoclasts and/or osteoblasts, and fibrous tissue replacement of marrow. The specimen shows disordered appearance of the bone and the multiple intersecting lines.

■
Complication rates for percutaneous interventional procedures are low (1-2%). Potential risks for epidural injections include dural injury, cerebrospinal fluid leak, infection, nerve puncture, intrathecal injection, and intravascular injection. Furman and associates reported 8% incidence of inadvertent vascular puncture from lumbar transforaminal injection. In this patient, there was injection into an L2 radiculomedullary artery, which ultimately caused catastrophic spinal cord ischemia and infarction. The dominant radiculomedullary artery, artery of Adamkiewicz, is the major blood supply for the anterior cord. Adamkiewicz enters the cord on the left from T9 to L2 level in 85% of people. The MRI scan shown, taken 48 hours after injury, indicates classic cord infarction with hyperintense cord signal on sagittal film. The axial image also shows hyperintense signal, predominantly in the gray matter with "owl's eye" pattern. Epidural hematoma would show a high T2 signal extradural compressive lesion on MRI. Intravenous injections are rarely dangerous. L2 nerve injury from a puncture would cause unilateral L2 nerve pain (dysesthesia), hypoesthesia, and/or palsy.

■
Because of the increasing rates of obesity, gastric bypass surgeries are becoming increasingly prevalent. Gastric bypass surgery is associated with negative effects on bone metabolism and can result in decreased bone mass. Some risk factors include changes in absorption (vitamin D), loss of muscle mass, and hormone changes. In a study of 48 patients undergoing Roux-en-Y gastric bypass, DEXA 6 months and 12 months postoperative from gastric bypass noted a 5% and 8% decrease, respectively, in femoral neck bone mineral density, compared with preoperative density. In patients with osteopenia or osteoporosis undergoing instrumented spinal fusion, failure of instrumentation may arise and presurgical planning is required. In patients with a history of gastric bypass undergoing instrumented spinal fusion, preoperative DEXA scan can diagnose osteopenia and/or osteoporosis and an appropriate surgical plan can be formulated.

■
This patient has classic neurogenic shock, which usually occurs when a cervical or high thoracic cord injury disrupts the autonomic pathways and causes a loss of sympathetic tone. Characteristic hypotension and bradycardia are present due to an unopposed vagal tone. Low cardiac output also is present, along with venous and arterial dilatation. The treatment for neurogenic shock is administration of agents called pressors (phenylephrine, dopamine, dobutamine, and norepinephrine) to improve cardiac contractility and increase peripheral vascular resistance. Atropine is given to increase the heart rate. Pressors are titrated to keep the mean arterial pressure above 80 and maintain spinal cord perfusion.

■
The patient has sustained a type 2 odontoid fracture. This is a common injury in elderly patients secondary to a hyperextension injury. The blood supply is tenuous and posterior displacement has been found to increase the risk of a nonunion.

■
Laminectomy without fusion for the treatment of cervical spondylotic myelopathy currently plays a minor role in the management of this disorder because of its many disadvantages. The actual incidence of postlaminectomy kyphosis is unknown, but is estimated to be between 11% and 47%. It can result in recurrent myelopathy if the spinal cord becomes draped over the kyphosis. In addition to the neurologic sequelae, the kyphosis itself can be a source of neck pain and deformity. Spondylolisthesis can develop, contributing to further cord compression. In this case, the patient had undergone a previous C4-5 anterior cervical diskectomy and fusion followed by a posterior laminectomy from C2 through C7, without fusion. This has resulted in severe kyphosis (i.e. postlaminectomy kyphosis) with grade IIIII spondylolisthesis at C3-4 and a grade I spondylolisthesis at C2-3. While ankylosing spondylitis can also result in a chin-on-chest deformity secondary to ankylosis, there is no evidence of marginal syndesmophytes in the imaging studies to suggest this diagnosis. The occiput is hyperextended on C1 on the lateral upright radiograph to compensate for the kyphosis in an attempt to maintain horizontal gaze. This results in an unusual appearing relationship on the imaging studies. However, there is no widening of the distance between C1 and the occiput and no evidence of soft-tissue injury on the MRI scans to suggest an acute injury. C3-4 demonstrates an unstable spondylolisthesis and was never intended to be included in the C4-5 fusion.

■
The AO Spine Classification Group has initiated a number of prospective studies on the treatment of cervical spondylotic myelopathy. In particular, Fehlings and associates showed that surgeon choice was important in selecting treatment, because the complications and outcomes were similar when comparing anterior to posterior approaches. Previously, studies showed more complications with posterior approaches. Further, anterior approaches are useful for more focal pathology in younger patients.

■
Translation-rotation injuries typically yield fracture dislocations. This injury pattern involves the disruption of skeletal and ligamentous elements of the spine to cause a maximum loss of stability, subsequent deformity in three planes (coronal, axial, and sagittal), and catastrophic neurologic injury.
Compression injuries occur when a force is applied in flexion and injures the anterior column. Compression injuries are usually stable and rarely have neurologic sequelae. Burst fractures occur through axially applied forces, which in turn cause injury to the anterior and middle columns of the vertebrae at minimum. Neurologic injury can occur through direct compression of the neural elements by bone fragments or hematoma or by absorption of the transferred energy. Flexion distraction injuries typically occur as forces are transmitted from anterior to posterior, causing injury to the middle and posterior columns.

■
The patient has sustained a Morel-Lavallee lesion, a degloving injury of the lumbosacral and pelvic regions. It is sustained by a shear force that tears the subcutaneous tissue off the underlying muscular fascia. A resulting seroma develops secondary to blood, fat, and lymphatic fluid. The seroma often needs to be either percutaneously or surgically drained, depending on the size and associated bony injuries. Risks of inappropriately treated lesions can result in infection, tissue necrosis, or a chronic seroma.

■
The MRI findings reveal age-related degenerative changes in the cervical spine, which is a very common finding in the adult population. Boden and associates evaluated cervical spine MRI findings on 63 asymptomatic subjects and found that the prevalence of having at least one degenerative disk was approximately 57% in those older than age 40 years.

■
The use of DBM has been shown to be an effective bone graft extender when combined with local bone. Kang and associates performed a side-by-side comparison of ICBG on one side of a lumbar fusion and local bone and DBM. Both sides showed equivalent fusion rates. However, the amount of bone morphogenetic proteins available in DBM has been shown to vary wildly between different preparation of DBM and even within different lots of the same DBM. This is thought to be related to variability in donors and different companies’ processes to prepare the DBM. There has been no direct comparison between DBM and calcium phosphate. DBM has not been directly compared with local bone. It is most commonly used to extend local bone and not to replace it.

■
Disruption of the posterior ligamentous complex is an important determinant of the stability of a burst fracture. This patient is neurologically intact and his MR images do not reveal posterior ligamentous complex (PLC) disruption. The standing radiograph confirms that overall alignment is acceptably and relatively preserved. Nonsurgical treatment with or without a brace is acceptable in this scenario; however, the patient should not be cleared to resume full activity until fracture healing, which may be as long as 3 months after the date of injury. Anterior or posterior surgery should be reserved for patients with PLC disruption, neurological injury, or, in some cases, multiple trauma.

■
Pelvic incidence is a fixed sagittal parameter in adults. Figure 3 represents the pelvic incidence. Figure 1 represents the pelvic tilt. Figure 2 is an indirect way of measuring the sacral slope, as sacral slope = pelvic incidence - pelvic tilt. Figure 4 represents the sacral slope.

■
This patient has the clinical symptoms of a right L4 lumbar radiculopathy. The MRI taken at L4-5 shows a far-lateral/foraminal disk herniation. This disk herniation would compress the exiting L4 nerve root along with its dorsal root ganglion. The traversing right L4 nerve root would be seen best in an axial MRI at the L3-4 level. The exiting right L5 nerve root would be seen best in an axial MRI at the L5-S1 level. The disk herniation in question is right sided. The left neuroforamen is free in the axial MRI.

■
The patient has autosomal dominant osteopetrosis type II, which is also known as AlbersSchonberg disease. It can be associated with sclerosis of the skull base, leading to cranial nerve dysfunction such as hearing loss. It is also associated with marrow replacement leading to anemia and can be associated with fractures. The images show increased bone density, and osteopetrosis type II can be associated with a “bone within a bone” type appearance. CTSK mutations are associated with pyknodysostosis, and TNSALP is associated with hypophosphatasia. Lead poisoning would not present with these findings.

■
Cervical jumped facets are severe injuries often associated with permanent neurologic deficits. In a series of 421 patients with cervical spine injuries enrolled in a multicenter prospective study, 135 patients (32%) had facet dislocations. Compared with the group without dislocations, the facet dislocation group had worse neurologic deficits on presentation and less motor recovery at 1-year follow-up.

■
The MRI scan reveals a large posterior element tumor, which is compressing the spinal cord. Multiple lesions within the spinal column are consistent with multiple myeloma. Myeloma is a radiosensitive tumor. Additionally, he has a SINS of 6. This score helps the treating physician determine the tumor-related instability of the vertebral column to guide the decision for operative management. A SINS of 0-6 is thought to be stable; 7-12, potentially stable, and >13, unstable. Appropriate treatment in a neurologically intact patient with a radiosensitive tumor with a low SINS would be radiation treatment versus surgical treatment, despite the degree of spinal cord compression.

■
The patient has a classic presentation of early ankylosing spondylitis. Sacroiliac joint fusion is the earliest radiographic finding and is typically followed by cephalad spinal progression. Early treatment of ankylosing spondylitis consists of nonsteroidal anti-inflammatory drugs and physical therapy to preserve spinal motion. HLA-B27 testing is positive in most (about 95%) patients; however, it is not pathognomonic because it can be positive with other conditions. Considering the progressive nature of this disease, further work-up in a patient with potential ankylosing spondylitis is not warranted. Sacroiliac joint anesthetic injections and sacroiliac fusion are not recommended treatments for early ankylosing spondylitis. Aspiration of the sacroiliac joints can be done if sacroiliac joint infection is suspected; however, in the absence of fever or other constitutional symptoms, infection is unlikely.

■
Patient satisfaction ratings are increasingly viewed as important parameters for functional outcomes, as well as in delivering quality care. Psychosocial influence, however, plays a paramount role in perceived outcomes. Affective disorders like depression have a highly significant negative effect on patient-related outcomes and self-interpretation of health status. Verla and associates reported outcomes after fusion surgery and used SF-36, Visual Analog Scale, and Oswestry Disability Index scores before and at 1 and 2 years, postoperatively. They also specifically looked at patients who sustained complications (major and minor). The results showed no lasting effects from complications on patients' overall interpretation of health status.

■
The patient has previously undiagnosed ankylosing spondylitis. Radiographs reveal nonmarginal syndesmophytes throughout the lumbar spine. The CT scan reveals a nondisplaced 3-column fracture. Many patients with missed spinal injuries present in followup with neurologic worsening or progressive deformity. Fractures can often involve all 3 columns, including the posterior elements. In patients with ankylosing spondylitis, this represents an unstable injury and a high likelihood of displacement with nonsurgical treatment. Surgical treatment in the form of a posterior spinal fusion is indicated. Because the fracture is nondisplaced and the patient is neurologically intact, decompression via an anterior approach is not indicated. Bracing either with a TLSO brace or a soft corset will not provide sufficient stability for this fracture pattern. Physical therapy and NSAIDS are not indicated in this scenario.

■
The patient's history and examination findings are consistent with a lumbar disk herniation at the L5-S1 level. Weakness of the gastrocnemius and gluteus maximus are consistent with an S1 lumbar radiculopathy. Nerve root tension signs are also consistent with a disk herniation at L5-S1, which typically affects the traversing S1 nerve root.

■
This patient has progressive myelopathy secondary to ossification of the posterior longitudinal ligament. Diagnostic imaging reveals multilevel cervical cord compression from C4-6. The patient has maintained reasonable cervical lordosis. A posterior procedure such as multilevel laminoplasty decompresses the spine, is motion preserving, and has a low complication rate. Observation and cervical epidural injections are not viable options in patients with progressive myelopathy. Anterior cervical decompression, including corpectomy, is an option; however, anterior procedures have an increased risk of complications such as dural tear or cerebrospinal fluid leak. The axial CT image shows a "double layer" sign, which is consistent with dural ossification and increases the risk of dural injury with anterior decompression.

■
The patient has a giant cell tumor. Surgery remains the standard of care; however, the monoclonal antibody against RANKL has been shown to be effective in preventing tumor progression, and it is an effective nonsurgical option. Radiation is not recommended, as this is a benign tumor and the patient is young. En bloc resection has been shown to be effective, but the patient is hoping to avoid surgery. Bisphosphonates are not an effective treatment for giant cell tumors.

■
The American Spinal Injury Association (ASIA) provides a standard method of measurement of spinal cord injury. The ASIA impairment scale is based on a comprehensive motor and sensory examination. An ASIA A grade is ascribed to a patient with an injury with no motor or sensory preservation below the injury. An ASIA B grade is defined as no motor preservation below the level of injury but some sensory preservation below the injury level. An ASIA C grade is defined as a motor function grade of less than 3 below the injury level.
An ASIA D grade is defined as a motor function grade of greater than 3 below the injury level. An ASIA E grade is defined as a normal neurologic examination.

■
The patient has sustained a whiplash injury, which is a soft-tissue injury to the cervical spine. Her radiographs reveal loss of cervical lordosis secondary to muscle spasm. Various treatment options have been studied, ranging from aggressive physical therapy to immobilization. Early mobilization has been shown to provide the best treatment.

■
When planning surgical intervention for Scheuermann kyphosis, it is imperative that the instrumentation and fusion extend across the entirety of the deformity. Distally, this means extending across the first lordotic disk space. In this scenario, this disk is the L1-L2 disk, which means the fusion needs to extend to L2. Shorter and longer fusions are not necessary or appropriate.

■
The patient has a C1 burst fracture, as well as a grossly displaced C2 fracture. Surgical treatment should be considered for this patient who has good baseline function and wellcontrolled medical comorbidities. A cervical collar would not offer adequate stabilization for this fracture. Anterior reduction of this C2 fracture would be difficult, and screw fixation of C2 would not address the C1-C2 instability. A halo vest is considered a relative contraindication in the older patient population. Therefore, posterior C1-C2 fixation is the most appropriate choice.

■
The sagittal T2-weighted MRI scan shows moderate-severe multilevel cervical stenosis. The cord compression is noted to be not only at the disk levels but also at the midvertebral body levels, and the posterior longitudinal ligament appears to be thickened. The CT scan confirms that the posterior longitudinal ligament is indeed thickened and ossified, compatible with a diagnosis of ossification of the posterior longitudinal ligament. This diagnosis is most common in individuals of Japanese descent and has a genetic linkage. The anterior osteophytes are smaller than those seen in diffuse idiopathic skeletal hyperostosis and are not syndesmotic. Patients with ankylosing spondylitis typically have non-marginal syndesmophytes. Patients with rheumatoid arthritis may have evidence of instability at C1C2 on flexion-extension radiographs and subaxial subluxations.

■
The patient has a low-grade but high-dysplastic spondylolisthesis (vertical and domed sacrum) with severe spinal canal stenosis. The MRI scan shows the dysplastic sacrum and severe central stenosis associated with an intact pars interarticularis, bulging L5-S1 disk, and domed posterior sacrum. Although many treatments are available for low-grade isthmic spondylolisthesis, this spondylolisthesis condition requires a complete laminectomy and possible sacral dome resection because of the severe central stenosis with an intact pars interarticularis (no lysis) in a patient with early neurological signs (Figures 6 and 7 are CT scans of the L5 pars without evidence of a lysis). Patients with dysplastic spondylolisthesis without a lysis can develop cauda equina syndrome with loss of bowel/ bladder function and weakness of the gastrocsoleus muscles (sacral nerve roots) and should be recognized and treated with appropriate laminectomy decompression followed by spinal fusion, typically with posterior instrumentation and interbody fusion. A “Gill” laminectomy is described as removal of the lamina from pars interarticularis lysis and including the abnormal inferior facets. There is no lysis in this patient, and while laminectomy is needed, a Gill laminectomy is not possible. Transforaminal interbody fusion and percutaneous instrumentation does not address the central spinal stenosis.

■
In degenerative spondylolisthesis, indirect decompression of the spinal canal has been shown to be an effective treatment option. Malham and associates conducted a prospective study of 122 patients and reported an unplanned return to the operating room in 11 patients (9%). When reviewing these cases retrospectively, the authors felt that failure of indirect decompression should have been anticipated based on radiographic findings in 10 of these 11 patients who had high-grade, unstable spondylolisthesis or substantial bony lateral recess stenosis. Sato and associates reported an increase in the spinal canal area of 20%, whereas Castellvi and associates reported only a 9% increase. Park and associates reported that positioning the cage within the anterior one-third of disk space is better for achieving the restoration of the segmental angle without compromising the indirect neural decompression, if the cage was high enough.

■
MRI and CT scans of the cervical spine reveal extensive fusion of the cervical spine. This congenital cervical fusion is often associated with Klippel-Feil syndrome. Klippel-Feil syndrome is characterized by congenital fusion of the cervical spine, decreased range of motion of the cervical spine, and low posterior hairline. Sprengel’s deformity (high-riding scapula) can be found in up to 16.7% of patients with Klippel-Feil syndrome. Patients with Klippel-Feil syndrome may develop cervical scoliosis and cervical stenosis at the adjacent unfused level. The prevalence of congenital cervical fusion is reported to be 1 in 172.

■
Epidural abscess is a serious and potentially disastrous condition. Although medical management is effective in some situations, surgical decompression is considered urgent with the presence of a neurological deficit. Medical management can be considered in the case of a neurologically intact patient, particularly when the microorganism has been identified. If medical management is chosen, careful observation and serial examination for neurologic deterioration is required. Surgical decompression is indicated if a patient's neurologic status worsens or if medical management failure is noted. Additionally, diabetes, a CRP level higher than 115 mg/L, WBC higher than 12500/μL , and bacteremia have proven predictive of medical treatment failure. This patient would be a better candidate for urgent surgical decompression and subsequent IV antibiotics than for medical management.

■
Workers’ compensation is a system that provides healthcare and wage-replacement benefits for workers injured in the occupational setting. Back pain is the most common workers compensation claim in the United States, accounting for up to 25% of all claims and one-third of total compensation costs. Numerous studies have reported that workers’ compensation is an independent negative risk factor for unsatisfactory outcomes after surgical procedures.
Keeney and associates published a prospective study looking at which factors were predictive for proceeding to surgery in the workers’ compensation population. Their findings showed that young age (<35 years-old), female gender, and Hispanic ethnicity were negative predictive factors for proceeding with surgical treatment. Which medical professional the work compensation patient sought made a difference; nearly 43% of injured workers whose first visit was to a surgeon eventually underwent a surgical procedure.

■
The patient has degenerative disk disease with diskogenic back pain. Several studies in both humans and animals have implicated TNF-α, IL-1, and MMP in extracellular matrix degeneration and disk degradation. TGF-β, BMP-2, latent membrane protein 1, and growth and development factor-5 are all postulated to play anabolic roles in the intervertebral disk. Biglycan is a small leucine-rich proteoglycan that regulates extracellular matrix assembly within the disk. Noggin and gremlin are biochemical factors not involved in disk degradation.

■
Use of percutaneous pedicle screw fixation has been advocated in patients with chance fractures, thoracolumbar burst fractures without neurological compromise, and extensiontype fractures in ankylosing spondylitis. However, percutaneous fixation is not advocated for facet dislocations, which usually require open reduction prior to fixation.

■
Low back pain remains a common presenting condition to not only primary care physicians, but to subspecialists. Studies assessing the anatomy of the spine, to include the intervertebral disks, vertebral body morphology, facet joints, and the paraspinal muscles have been performed. Spinal stenosis is the only advanced imaging finding that has been associated with reproducible reasons for back pain.

■
Sagittal balance is the most reliable predictor of clinical symptoms and HRQL outcomes on the SRS 29, SF-12, and Oswestry Disability Index. Coronal balance, shoulder balance, curve magnitude, and degree of curve correction are less critical in determining clinical symptoms and outcomes.

■
The patient has several risk factors for postoperative VTE including older age, previous VTE, renal disease, and expected long duration of surgery to correct her deformity. VTE is uncommon after spinal surgery, but each patient must be evaluated individually, and this patient is at higher risk. It is unknown if the risks of chemical anticoagulation outweigh the benefits in this patient. IVC filters may be useful, but they are not considered the standard of care. Early mobilization will certainly help prevent VTE, but it will not completely mitigate her risk.

■
The MRI scans reveal a spinal cord with a noted central spinal canal syrinx. The patient has a normal neurological examination. There is no evidence of Chiari malformation or tethered spinal cord. Thus, for this patient, a neurosurgical evaluation is not required nor is a cerebral spinal fluid shunt. As the deformity has progressed past 50° in a skeletally immature teenager, brace treatment is no longer appropriate, and surgical correction of the scoliosis is the most appropriate treatment.

■
The natural history of cervical myelopathy is one of slow deterioration over time, typically in a stepwise fashion with a variable period of stable neurologic function. More recent studies suggest that surgery should be performed as soon as possible when cervical spondylotic myelopathy has been diagnosed. Both anterior and posterior are effective and there is no statistical difference between their outcomes. Surgical outcome is related to the patient's age, disease course, the presence of osseous spinal stenosis, preoperative comorbidities, the preoperative spinal cord functional score, and the presence of high-signal abnormalities on T2-weighted images. To improve the operative result, all the influencing factors should be considered. Patients with focal high-intensity intramedullary signal changes on T2weighted images have better clinical outcomes following surgery than do patients with demonstrable multisegmental high-intensity intramedullary signal changes on T2-weighted sequences. The transverse area and shape of the spinal cord at the involved segment may also be predictive of surgical outcome. With progressive compression, the cross section of the spinal cord changes from a boomerang shape to a teardrop shape to a triangular shape. In patients with a Nurick grade of I, there are signs of cord involvement, but gait remains normal. With a Nurick grade of II, there are mild gait abnormalities, not affecting the patient's employment status. With a Nurick grade of III, gait abnormalities prevent employment, but the patient remains able to ambulate without assistance. In Nurick grade IV, the patient is only able to ambulate with assistance. In Nurick grade V, the patient is chair-bound or bedridden. Clearly, it is desirable to operate when the patient is functioning with a Nurick grade of I or II. Whereas many patients presenting with cervical spondylotic myelopathy also report axial neck pain and radicular symptoms in the upper extremities, this is not always the case. Surgical intervention will generally be effective in eliminating this pain; however, the pain is not the determining factor for performing surgery. Surgery is performed to preserve and restore function.

■
The patient has symptoms and radiographic findings consistent with the diagnosis of myelopathy. Spinal cord ischemia has long been theorized to be the mechanism behind the development of myelopathy. However, recent experimental models have some no to minimal decrease is blood flow in cases of moderate myelopathy. Ischemia typically causes cell death by necrosis; however, human and animal studies have demonstrated that cell death in the setting of myelopathy is regulated through cell apoptosis. Vascular endothelial cells have been shown to decrease in number in the setting of myelopathy. IL-1 and MMP expression is increased in the setting of inflammation.

■
The patient has lumbar stenosis of L2-3 and L3-4. She has no spondylolisthesis or instability. For her condition, spinal fusion plays a minimal role. She has no evidence of instability, and her condition can be addressed through laminectomy only. No role exists for microdiskectomy, because her disease results from a combination of ligamentum flavum hypertrophy and facet hypertrophy.

■
When feasible, en bloc resection is associated with the least recurrence in the surgical management of chordomas. Denosumab has been used for the treatment of giant cell tumors, along with surgical resection. Preoperative embolization has not been associated with the prevention of recurrence. Postoperative radiation can supplement en bloc resection but is not a stand-alone modality that can prevent resections.

■
The MRI scan reveals a foraminal disk herniation originating from the L4-L5 disk space that has migrated into the foramen compressing the left L4 nerve root. There is no evidence of compression of the right L5 nerve root. Bowel and bladder dysfunction are not associated with L4-mediated nerve function. There is no evidence of pseudomeningocele.

■
The radiograph reveals an L5-S1 spondylolisthesis secondary to L5 spondylolysis. Patients with isthmic spondylolisthesis have fibrous tissue at the pars interarticularis, which contributes to bilateral L5-S1 foraminal stenosis. This typically results in L5 radiculopathy, which is the exiting nerve root at L5-S1. Lateral recess stenosis and hypertrophic ligamentum flavum are typically seen in degenerative spondylolisthesis.

■
The genitofemoral nerve is at risk at almost any level in the lateral transpsoas approach. The nerve provides sensory innervation to the anterior thigh and scrotum/labia. The ilioinguinal nerve provides sensory innervation to the mons pubis or labia in women and the upper scrotum in men. The femoral nerve is responsible for sensation to the anterior and medial aspects of the thigh, leg, and medial foot. It also provides innervation to knee extensor muscles. Prolonged decubitus positioning, especially with jackknife hyperextension, can cause stretching of the femoral nerve and transient weakness of the ipsilateral quadriceps.

■
Flexion-distraction injuries of the spine are frequently associated with concomitant intraabdominal injuries including hollow viscus injuries, mesenteric tears, and liver and spleen injuries. This is especially evident in seat-belt related motor vehicle collisions. Often patients with seat-belt injuries will have abdominal bruising or contusions that should be looked for on initial evaluation. General surgical or trauma team evaluation includes abdominal evaluation typically with CT evaluation of the abdomen or peritoneal lavage. Treatment of the spinal injury especially in a neurologically intact patient. should be delayed until proper evaluation for abdominal injuries with this fracture pattern.

■
The sagittal T2-weighted and axial T2-weighted images show a lesion within the T8 vertebral body that involves the posterior elements. There is an associated epidural component that results in compression of the spinal cord. The sagittal reconstructed CT image shows a lytic lesion within the T8 vertebral body. This pattern of vertebral body involvement with preservation of the adjacent disks and endplates in a 65-year-old patient is most compatible with a diagnosis of a tumor. The most likely tumor is a metastatic lesion. A CT-guided biopsy will confirm this diagnosis. Although thoracic tuberculosis does not typically cross the disk space, the lack of an anterior soft-tissue component decreases the likelihood of this diagnosis.

■
The patient has a diagnosis of fibromyalgia, which the American College of Rheumatology defines as chronic widespread pain with at least 11 of 18 possible tender points. Etiology is multifactorial, but there is a genetic predisposition. Some associated factors include: history of widespread pain and hyperalgesia, sleep disorder, inactivity, functional disability, concomitant anxiety or mood disorder, and fear avoidance behavior. The most effective treatment for fibromyalgia is multimodal; however, pharmacologic neuromodulation (use of antiepileptic drugs, tricyclic antidepressants, selective serotonin-reuptake inhibitors, and serotonin norepinephrine reuptake inhibitors) has been found to be moderately successful in treating widespread pain and hyperalgesia. These medications are aimed at altering the neurochemistry of the central nervous system and diminishing the perception of pain. Other treatments include physical activity to address inactivity and functional disability, sleep quality improvement, interventions treating anxiety and mood disorders, and interventions targeting fear-avoidance behavior. Surgery, specifically fusion procedures, has not been found to be effective in such patients with discogenic changes only; without instability or stenosis. There is no high-level study showing efficacy of either lumbar or cervical epidural injection in patients with fibromyalgia who complain of neck or back pain without radiculopathy. The use of opiates and anxiolytics should be closely monitored because this patient population is especially at high risk for abuse and dependence.

■
The patient has a hyperostotic condition of the cervical spine, most likely ankylosing spondylitis. Because of a rigid and osteoporotic spine, relatively minor falls can result in unstable spinal injuries with significant instability and a high risk for neurologic sequelae. The patient has an unstable injury at C6 with an incomplete spinal cord injury, necessitating urgent decompression and stabilization. Studies have shown that, in patients with ankylosing spondylitis, stand-alone anterior stabilization results in a high failure rate. Halothoracic vests carry a high risk of septic and pulmonary issues, especially in the elderly. Uninstrumented fusion will provide insufficient stability in such patients.

■
Cervical epidural injections have been associated with cervical epidural abscesses and spinal cord injury. This patient’s history of recent cervical epidural injection should raise a suspicion of epidural abscess and prompt additional imaging. In a series of 367 patients with epidural abscesses, Shah and associates identified 99 patients who failed nonsurgical management. Factors predictive of failure of nonsurgical management included: motor and sensory deficits, compression/pathologic fracture, active malignancy, and diabetes mellitus. Dorsal location of the epidural abscess was predictive that nonsurgical management can succeed, as opposed to ventral location of the abscess.

■
Several studies have found that rates of neurologic deficit and mortality are higher for patients with ankylosing spondylitis and a spinal fracture than for age-matched controls. The 2011 work of Schoenfeld and associates, which directly compared patients with cervical fractures in ankylosed spines to age- and sex-matched controls who also had cervical fractures but no ankylosing condition, demonstrated that those with ankylosing spondylitis were at elevated risk for mortality for up to 2 years after sustaining a fracture. In a study by Westerveld and associates, the rate of neurologic deficit among patients with ankylosing spondylitis and a spinal fracture was 57.1% compared to 12.6% among controls.

■
Central/posterior lateral disk herniations affect the traversing nerve root. Comparatively, foraminal disks or extra foraminal (far lateral) disks affect the exiting nerve root. Here, a far lateral disk is seen on the right of the image (patient’s left side) at L3-L4. This would affect the L3 nerve root once it has exited the neural foramen. Patients would experience pain on the anterior thigh and potentially weakness in the quadriceps.

■
The patient has an epidural abscess following a dental procedure. The epidural abscess spans from C2 to the upper thoracic spine. He has severe neck pain, neurologic changes, and elevated laboratory markers. Sang and associates have demonstrated that, in patients older than 65 years with a methicillin-resistant Staphylococcus aureus infection, a history of diabetes, and neurologic deficits, nonsurgical management has a 99% chance of failure. Prompt surgical decompression to evacuate the abscess followed by antibiotic treatment is the best method of treatment for this patient.

■
In a retrospective study of patients with epidural abscess from two academic medical centers, a predictive algorithm was developed to help identify which patients will develop a motor deficit. Multivariate analysis allowed points to be assigned to each risk factor. A sensory deficit was associated with 10 points; urinary retention/incontinence, 8 points; fecal incontinence/retention, 5 points; abscess above the conus medullaris, 4 points; diabetes, 2 points; WBC count >12x109 cells/liter, 2 points, and the presence of multiple epidural abscesses, 4 points. Smoking was not found to be predictive of a motor deficit. A dorsally based abscess was found to be protective of having a deficit, but a ventral or circumferential abscess was not. The use of steroids in the setting of infection is not recommended.

■
Whereas subjective complaints of leg pain are common among patients seeking surgical treatment for spondylolisthesis, documented neurologic deficit or radiculopathy is seen less frequently. Subjective decreases to light touch over the dorsum of the foot and mild weakness of the extensor hallucis longus are the most common neurologic abnormalities, correlating with L5 nerve root irritation as seen with L5-S1 spondylolisthesis. Many patients with spondylolisthesis report hamstring tightness; however, these structures are not usually weak. Quadriceps and tibialis anterior weakness is seen with L4 nerve root irritation. The gastrocnemius is generally weak in S1 nerve root syndromes.

■
Medical litigation is common in spine surgery. In a study evaluating “spine surgery” related legal cases from 1988 to 2015, 234 cases met the inclusion criteria. Diagnostic delay cases were significantly associated with plaintiff verdict or settlement. Therapeutic delay cases were also associated with plaintiff verdict or settlement. Catastrophic complications resulted in larger payouts (6.1 million) as compared with noncatastrophic complications (2.9 million). There is no association between specialty (neurosurgery or orthopaedic spine surgery), patient age/sex, and case outcome or award.

■
During an anterior approach to the L4-L5 disk space for anterior lumbar interbody fusion, meticulous exposure is paramount to allow for safe preparation of the disk space and subsequent arthrodesis. Although all of these structures can come into play during the exposure, the aorta lies anterior to the L4 vertebral body and bifurcates at this level. The vena cava bifurcates just distal to this. The ureters lie to both sides of the anterior spine. The right common iliac artery and the left common iliac vein originate after the bifurcation of the great vessels and lie caudal to the L4 vertebra.

■
Several clinical outcome measuring tools have been used in orthopaedics to assess health status in clinical care, research, and cost-effective analysis. PROMIS was designed to focus on psychometric characteristics, which would render it precise, reliable, and versatile. PROMIS also uses computerized adaptive testing (CAT) in contrast with conventional outcome measures (SF-36, ODI, or NDI). With CAT, an algorithm customizes item delivery based on responses to previous items. This enables precision with fewer questions and mitigates examinee fatigue or loss of focus. PROMIS also uses an easily understandable Tscore (normalized to general population) as an output. A score of 50 is set as the mean, and the standard deviation is set at 10 points. PROMIS has been compared with conventional measures (general health and disease-specific patient related outcome measures) and has been found to improve coverage of relevant health domain, increase reliability, and reduce respondent and administrative burden. PROMIS has been extensively studied in the following orthopaedic disorders: foot and ankle, upper extremity, and spine.

■
The patient has radiographic findings compatible with diffuse idiopathic skeletal hyperostosis (DISH) of the cervical spine. Characteristics of DISH include flowing, non-marginal osteophytes at four or more levels. Patients with DISH develop a significant loss of flexibility of the spine. The spine acts more as a long bone with minimal force needed to create unstable fractures. Any minor trauma in patients with DISH should be worked up aggressively to rule out occult fracture. In this patient, radiographs fail to clearly rule out a fracture; therefore, CT of the cervical spine is indicated. Without a suspicion of history of a head injury, admission specifically for a possible intracranial hematoma is not warranted. The more concerning injury in a patient with DISH is occult neck fracture. Treatment with a soft or hard collar is not advised until a fracture is ruled out. Repeat radiographs are unlikely to show any occult fractures, and flexion and extension views would not be advised in a patient with a suspected vertebral fracture.

■
The incidence of surgery is increased in patients 80 years of age and older. Patients aged 80 years and older enrolled in the Spine Patient Outcomes Research Trial and undergoing surgery for lumbar stenosis and spondylolisthesis were compared with patients younger than 80. In the older age group, surgical treatment was associated with statistically significant clinical improvement compared with nonsurgical management. No statistically significant increase was observed in complications or mortality compared with younger patients.

■
Pelvic incidence (PI) is the anatomic angle between the sacral end plate and a line connecting the center of the femoral heads. Increased pelvic incidence has been found to correlate with the incidence and severity of spondylolisthesis. Patients with increased PI require increased lumbar lordosis to restore sagittal balance. Pelvic tilt (PT) and sacral slope (SS) have also been found to correlate with lumbar lordosis; however, both PT and SS can change depending on pelvic rotation. PI is the only permanent pelvic parameter that is unaffected by pelvic rotation. Acetabular version has not been found to be associated with lumbar lordosis.

■
Cervical disk replacement is indicated for 1-2 levels depending on the chosen implant. Studies have examined its use in patients <60 years for symptomatic cervical radiculopathy and/or myelopathy.

■
The radiograph and sagittal T2-weighted MRI scan show multilevel degenerative changes and subaxial subluxations with anterolisthesis at C3-C4 and C4-C5 and retrolisthesis at C5C6. In addition, there is evidence of midcervical kyphosis. Such findings are often seen in patients with rheumatoid arthritis. Patients with osteomyelitis typically show increased signal intensity in the disks and vertebral bodies. Patients with ankylosing spondylitis typically show ankylosis of the disks and vertebral bodies. Age-related degenerative changes typically manifest as degenerative disk disease with occasional single-level spondylolisthesis, but not typically multilevel spondylolisthesis, as seen in this patient. The spinous processes are intact; these changes do not appear to be postoperative.

■
Instrumentation of the osteoporotic spine is becoming more common as the population ages. Some intraoperative options to reduce pedicle screw failure rates include augmenting the pedicle screw with PMMA, using a fenestrated screw designed for injection of the PMMA through the screw, and using hydroxyapatite coated screws. Teriparatide is a parathyroid hormone analogue used as a second-line treatment for osteoporosis. Preoperative administration potentially can increase bone quality. Postoperative administration of teriparatide has been shown to increase lumbar fusion rates. In the setting of osteoporosis, multilevel interbody fusion can increase the risk of implant subsidence. Although iliac crest bone graft is the gold standard graft used to obtain fusion, it does not have immediate impact on the rate of implant failure in osteoporosis.

■
The patient has thoracic disk herniation. This is causing significant compression of her spinal cord. Her symptoms and physical examination are consistent with myelopathy. Given the patient’s symptoms, surgical treatment is most appropriate. A significant number of thoracic disk herniations will calcify, which can alter the surgical approach. A CT scan (or CT myelogram) is the best way to detect calcification. Flexion extension images, while helpful, may not detect the calcified disk. Instability in the thoracic spine is uncommon. Given the patients hyperreflexia, lumbar pathology contributing to the patient’s complaints is unlikely. Pulmonary function tests may be considered for patients requiring a transthoracic approach, but they are unlikely to be abnormal in an otherwise healthy patient.

■
The figures show a grade 1 spondylolisthesis at L4-L5 along with a left sided facet cyst in a patient with ongoing symptoms despite nonoperative management. A lumbar decompression with a fusion would be an appropriate treatment option in this patient. There is no evidence in the literature for a lateral lumbar interbody fusion without directly decompressing the spinal canal for treatment of spondylolisthesis in the presence of a large facet cyst. Such procedures have been shown to be successful for treatment in the presence of spinal stenosis from ligament hypertrophy, disk bulge, foraminal stenosis. However, there is no evidence for their effectiveness in the presence of a large facet cyst. Similarly facet cyst aspiration has no evidence for treatment of this pathology. A facetectomy and cyst removal may adequately decompress the L4-L5 level. However, this is likely to create further instability in the presence of a spondylolisthesis.

■
When instrumenting the spine posteriorly, distraction forces posterior to the axis of rotation result in kyphosis and compression forces result in lordosis. Thus, when correcting a lumbar scoliosis deformity posteriorly, the convex rod is placed first with a compressive force to obtain scoliosis correction, as well as improved lumbar lordosis. A distraction force typically follows this in the concavity of the curvature. Similarly, distraction forces anterior to the axis of rotation with anterior spinal instrumentation will result in lordosis, and compression forces will result in kyphosis. Rotation is obtained by exerting a force in the axial plane. Cantilever forces occur when a rod is rigidly attached to one end of a spinal deformity and a load is used to create a moment at the point of attachment to the support, i.e. used in kyphosis correction.

■
This patient has a right-sided C5-C6 disk herniation causing C6 radicular symptoms in the right upper extremity. Studies have shown that both ACDF and posterior foraminotomy confer similar results in terms of pain relief and functional outcome. Patients treated with posterior foraminotomy are at higher risk for neck pain and recurrence of radiculopathy at the same level. Those who receive ACDF are at higher risk for occurrence of radiculopathy at an adjacent level.

■
Interspinous devices are utilized to mitigate the symptoms of neurogenic claudication secondary to lumbar spinal stenosis with forced forward flexion. Interspinous devices can be classified as a distracting device or a stabilizing device. The inhibition of extension with a blocking device widens the central canal and foraminal height and decreases the load on the facet joints. Various types of interspinous devices have been shown to decrease the ODI and VAS scores.

■
Ankylosing spinal disorders, including ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, are conditions that make the spine rigid and at risk for 3-column unstable fractures. Spinal fractures in these patients pose high risk for complications and death and patients should be counseled and observed closely. Mortality strongly correlates with older age and increased number of comorbidities.
These spine fractures often are not seen at the time of initial evaluation, and a delay in diagnosis can occur in up to 19% of cases. This is particularly common in the setting of non- or minimally displaced fractures following minor injuries. A delayed diagnosis can lead to displacement of a previously nondisplaced fracture that can incur a high neurologic injury risk. Advanced imaging with a CT scan or MRI should be obtained for patients with ankylosing spinal disorders even when minor injuries occur. Although bracing and observation can be used, posterior multilevel spinal instrumentation is typically required to obtain adequate spinal stabilization.
The radiographs show an osteopenic ankylosed thoracic spine; the anteroposterior radiograph clearly shows fusion of the sacroiliac joints. Recognition of these radiographic findings is important when evaluating patients after an injury.

■
Oglesby and associates evaluated the incidence of VTE after 273,000 cervical procedures using a National Inpatient Sample Database (from 2002 to 2009). Risk factors for deep venous thrombosis (DVT) and pulmonary embolism were stratified. The overall rate of VTE was 5 per 1,000 procedures. Specific increased risk factors include: posterior cervical fusion with an incidence of 13.4 per 1,000 patients (odds ratio 2.3), male gender (odds ratio 1.8), fluid and electrolyte imbalance (odds ratio 2.2), postoperative anemia (odds ratio 4.8), and pulmonary vascular pathology (odds ratio 3.7).

■
The patient has classic symptoms of myelopathy with upper motor neuron signs on examination. His symptoms have been present for years, and are getting worse. The cervical spine MRI scan shows spinal stenosis with multilevel spondylosis causing spinal cord compression at multiple levels. With the longstanding duration of the patient's signs and symptoms, combined with involvement of multiple levels in the cervical spine, posterior multilevel laminectomy and fusion is the best treatment option. Two-level anterior diskectomy and fusion would address the two areas of most severe narrowing, but it would fail to decompress the other stenotic areas which also require decompression. Posterior cervical foraminotomies would only address radicular symptoms, which are not present in this patient, and would not succeed in decompression of the spinal cord. Cervical epidural injections are not indicated for myelopathy symptoms, and may in fact place this patient at risk for neurologic deterioration.

■
The figures show a unilateral floating mass fracture of C4 with horizontalization of the C4 facet on the left side and <25% anterior listhesis at C4-C5. These injuries are considered 2 level injuries; therefore, the injury in this patient is a C3-C4 and C4-C5 injury. Nonoperative treatment has been found to be unsuccessful in managing these injuries and lead to subluxation over time. Surgical fixation of the two involved levels, either anteriorly or posteriorly is acceptable. Surgical treatment of only one of the levels may leave the instability at the second level unaddressed.

■
Recombinant human PTH benefits patients with osteoporosis by stimulating osteoblastic bone formation and reducing osteoblastic apoptosis. Treatment reduces vertebral fractures by 65%. PTH analogs act similarly and reduce vertebral fractures by 47%. Bisphosphonates reduce the resorptive activity of osteoclasts and cause a dissociation of bone formation and resorption that favors bone formation and reduce vertebral fractures by 50% to 70%. Selective estrogen receptor modulators inhibit bone resorption and reduce vertebral fractures by 35%. Humanized monoclonal antibodies inhibit osteoclast formation and reduce vertebral fractures by 68%.

■
Maintaining MAPs 85 mmHg to 90 mmHg has been advocated by the American Association of Neurological Surgeons/Congress of Neurological Surgeons for up to 7 days to increase spinal cord perfusion. The thought is that by increasing MAPs, spinal cord ischemia can be avoided. An intensive care unit stay is often needed to monitor the MAPs and vasopressors may be needed. From the vasopressors used (dopamine, norepinephrine, phenylephrine), dopamine has led to most complications. There has been a case report of increased MAP use in the setting of incomplete spinal cord injury leading to posterior reversible encephalopathy syndrome. Randomized trials to determine which MAP goal is ideal are undergoing.

■
The patient has MRI findings throughout her lumbar spine consistent with old compression fractures. Given the imaging findings and advanced age, she is at high risk for osteoporosis and subsequent fragility fractures. Management should consist of a DEXA scan to evaluate her degree of osteoporosis and begin medical treatment as appropriate. Because acute fracture is unlikely, and she has no neurologic compromise, neither bracing nor surgical treatment is indicated.

■
The patient has a burst fracture of the spine. The use of percutaneous pedicle screws without fusion has been shown to result in less blood loss and decreased operating room time. It has been shown to produce equivalent outcomes compared with fusions and has not been associated with increased kyphotic deformity. Although the screws can be removed once the fracture has healed, this is not necessary if the patient is asymptomatic.

■
The patient with cauda equina syndrome should be taken to surgery urgently to provide the best chance of symptom resolution. However, many studies indicate that patients with cauda equina syndrome do not return to a completely normal status even following urgent surgery. Whereas pain is typically relieved after surgery, other deficits, especially bladder and sexual dysfunction, may persist. Particularly in light of the patient's severe saddle anesthesia, she may have a poor prognosis for recovery of normal bladder function.

■
In 2016, Wang and associates performed a meta-analysis of 12 retrospective studies and reported an overall incidence of perioperative VTE of 2% in patients following spine surgery. The following were found to have increased risk for perioperative VTE: preoperative poor ambulatory status (odds ratio 4.8), diabetes (odds ratio 2.12), and hypertension (odds ratio 1.59). In contrast, surgical time, age, BMI, smoking, and specific surgical procedure were not associated with increased risk of perioperative VTE. In another study, Piper and associates used data (22,434 spine surgeries) from the American College of Surgeons National Surgical Quality Improvement Program database from 2006 to 2010. Nine patientspecific risk factors were associated with VTE, including hypertension (odds ratio 2.08), dependent functional status (odds ratio 4.34), malignancy (odds ratio 6.83), inpatient status (odds ratio 7.13), paraplegia (odds ratio 3.74), and quadriplegia (odds ratio 5.63).

■
Spinal fractures in patients with ankylosing spondylitis are unstable and generally necessitate surgical intervention. In a patient with a spinal fracture in the setting of ankylosing spondylitis, posterior instrumented fusion is an appropriate surgical procedure. Treatment with a thoracolumbar orthosis is not an option for patients with extension distraction injuries in the setting of an ankylosed spine because of risk for displacement. Similarly, simply checking upright radiographs is generally not advocated. Laminectomy alone is inappropriate for this patient because there is no cord compression and neurologic symptoms are absent. Stabilization is the treatment goal.

■
BMP is contraindicated for use in the anterior cervical spine. The U.S. Food and Drug Administration produced a warning to not use BMP in anterior cervical surgery due to a higher risk of death (secondary to soft-tissue swelling). When it is used in the lumbar spine, BMP results in lower reoperation rates, higher fusion, and greater cost efficacy when the cost of implants and reoperation are considered.

■
This patient has a cervical disk herniation with symptomatic radiculopathy. The herniation is still in the acute phase, and the patient gives no account of clinical progression or worsening. Generally, the natural history of cervical radiculopathy is favorable, with resolution in most cases. Nonsurgical management remains a reasonable treatment option at this point. The use of opioid medications carries the risk of addiction or abuse; therefore, prescribing opioids at this time is not desirable. Because she does not have myelopathy or rapidly progressive neurologic symptoms, surgical treatment also is not advisable at this time. The onset of symptoms remains acute at only 4 weeks.

■
In the absence of any severe progressive neurologic deficits or other red flags, the most appropriate management for an acute lumbar disk herniation is nonsurgical care. Nonsurgical treatments such as limited bed rest, anti-inflammatory medications, and judicious use of pain medications are appropriate in this clinical situation. Up to 90% of patients will experience a resolution of symptoms without the need for surgical intervention within a 3-month window. In the acute setting, with no neurologic deficits, immediate MRI of the lumbar spine is neither beneficial nor warranted. Likewise, without signs of an acute deficit, emergent surgical intervention and caudal epidural steroid injections are not needed.

■
Lumbopelvic fixation (pedicle screws, iliac screws) has more stability than a stand-alone iliosacral screw. The initial description of iliosacral screw fixation of U-shaped sacral fracture by Nork and associates recommended non-weight bearing for 2 months and use of thoracic lumbosacral hip orthosis for 6 to 8 weeks. In a comparison of lumbopelvic fixation with iliosacral screws, Kelly and associates demonstrated that lumbopelvic fixation allowed immediate weight bearing and increased likelihood of discharge to home; however, iliosacral screw fixation led to a shorter operative time and less blood loss.

■
Angle A represents pelvic incidence (PI), a constant anatomic relationship between the pelvis and sacrum. Angle B represents pelvic tilt, and angle C represents sacral slope. Pelvic tilt and sacral slope can change depending on the rotation of the pelvis. Pelvic incidence has been found to directly correlate with the magnitude of lumbar lordosis and thoracic kyphosis because it determines the angle at the base of the spine (the lumbosacral junction). To obtain sagittal balance, the remainder of the spine compensates, resulting in the degree of lumbar lordosis and thoracic kyphosis to maintain an upright posture. Thus, PI must be considered in the evaluation of sagittal balance and potential reconstructive procedures. Angle D represents the T1 angle.

■
Traumatic sacral fractures in younger patients are often high-energy injuries. They are commonly associated with other injuries, including fractures of the pelvic ring and long bones. Because of their close anatomic location, sacral fractures are commonly associated with injuries to the iliac vessels. Significant soft-tissue injuries, including fascial degloving injuries are not uncommon. Neurological injuries can occur in up to 25% of patients with sacral fractures. They can range from nerve root injuries to cauda equina syndrome. The presence and severity of a neurological injury has been shown to have the greatest impact on quality of life following these injuries.

■
Interbody fusion, when compared to PLF, is a predictor of more substantial blood loss. Multilevel posterior lumbar interbody fusion (PLIF) is an independent predictor of blood loss for posterior spine fusion. Some retrospective studies suggest that fusion rates are higher for transforaminal lumbar interbody fusion (TLIF) than PLF, but this finding has not been borne out in prospective studies. The main advantage of TLIF in the context of this question is restoration of neuroforaminal height, and many surgeons will consider TLIF or PLIF for that reason. The parasagittal MR image seen in Figure 3 shows neuroforaminal narrowing. The pre- and postsurgical radiographs show a difference in neuroforaminal height.

■
Myelopathic hand is a term used to describe a patient with myelopathy and myelopathic findings in the hand. Typical myelopathic symptoms include upper motor findings, including difficulty with hand dexterity, hyperreflexia, a positive Hoffman sign, spasticity, a positive Romberg sign, and gait changes/ataxia.

■
Posterior C1-2 fusion with instrumentation provides stability and pain relief with excellent clinical outcomes despite the loss of C1-2 motion. Hard collar immobilization and halo vest immobilization both carry a substantial risk of nonunion in this patient because of her age, fracture displacement, residual fracture gap, and medical condition. Anterior odontoid screw fixation theoretically preserves C1-2 motion. In this case, the fracture is not reduced. Concentric reduction is a requisite for osteosynthesis of the odontoid. Her body habitus also may not allow anterior odontoid fixation.

■
CT of the cervical spine is fast and readily available in most centers. The reported sensitivity of CT is greater than 95%, whereas specificity is almost 100%. In contrast, plain radiographs have a sensitivity of 70% and a missed injury rate of 15% to 30%. CT also has been found to be as cost effective or more cost effective compared with plain radiographs in diagnosing cervical injuries. MRI is expensive, not always readily available, and inferior to CT in diagnosing bony injuries. In this patient, dynamic imaging in the form of flexion-extension views is contraindicated as a first line radiographic test. The patient may have an unstable cervical injury which could be exacerbated with motion. The patient's mental status also does not allow voluntary motion. The maneuver would have to be done by the physician or radiology technician.

■
The patient has a chordoma. The physaliferous cells in the histologic figure confirm the diagnosis. The two most common primary tumors of the spine are chordoma and chondrosarcoma. In both cases, the literature supports en bloc resection. Curettage is associated with high local recurrence rates and should be discouraged as a stand-alone treatment. Palliative radiation is not known to be effective because the radiation dose is <50 Gy. There are no effective chemotherapies for either chordoma or chondrosarcoma.