Potential Mechanism for Some Postoperative C5 Palsies: An Anatomical Study.

STUDY DESIGN: Anatomical Study. OBJECTIVE: Determine if shoulder depression (eg, taping the shoulders) might result in C5 nerve traction and subsequent injury. SUMMARY OF BACKGROUND DATA: Postoperative C5 nerve palsy is a recognized entity that is still often enigmatic. Inferior shoulder depression is usually employed to assist with surgical visualization during cervical spine procedures. METHODS: In the supine position, 10 adult fresh frozen human cadavers underwent dissection of the spinal cord and its adjacent dorsal, ventral roots, and spinal nerves from C4 to T1. In the supine position, the head was rotated ipsilaterally, contralaterally, and in lateral flexion. The shoulder was elevated, retracted, protracted, and depressed all with direct observation of nerve roots, intradural ventral/dorsal rootlets, or the spinal cord. The effects of these movements upon the cervical nerve rootlets were measured. RESULTS: The greatest displacement of nervous tissue was generated by shoulder depression and occurred primarily at the intradural rootlet level. The nerve rootlets that underwent the greatest average displacement were found at C5, with a decreasing gradient to C7 and no gross motion at C8 or T1. With maximal shoulder depression, C5-C7 rootlet tension produced cord movement to the ipsilateral side, touching the dura mater covering the lateral vertebral column with the C5 nerve root moving farthest. CONCLUSION: Shoulder depression is often used during cervical spine surgery. In cadavers, shoulder depression causes significant tension and displacement of the C5 nerve rootlets, and in the extreme, cord displacement to the ipsilateral side. This could be a mechanism for injury, putting patients at greater risk for postoperative C5 palsy. LEVEL OF EVIDENCE: 5.

Extraforaminal compression of the L5 nerve: An anatomical study with application to failed posterior decompressive procedures.

This anatomical study was performed to elucidate the pertinent foraminal and lateral L5 nerve anatomy to enhance our understanding of possible neurologic causes of failed decompression surgery. Persistent extraforaminal L5 nerve compression is a possible cause of persistent symptoms following lumbosacral surgery. The amount of extraforaminal space for the L5 ventral ramus was examined in fifty adult human skeletons (100 sides). Based on morphology, the specimens were then categorized (types I-IV) on the basis of the bony space available for the nerve at this location. Next, 25 embalmed adult cadavers (50 sides) underwent bilateral dissection of the lower lateral lumbar region. The type of bony extraforaminal outlet was documented for each cadaver on the basis of our skeletal analysis. Lastly, segments (intra- and extra-foraminal) of the L5 ventral ramus were excised and examined histologically. Types I-IV outlets were found in 43, 31, 20 and 6 skeletal sides, respectively. For cadavers, 22,15, 10 and 3 sides were found to have types I-IV bony outlets, respectively. In cadavers, all type IV outlets and 70% of the type III bony configurations adjacent to the L5 ventral ramus had signs of neural irritation/injury including vascular hyalinization and increased fibrosis distal to the intervertebral foramen. No distal segments of type I and type II outlets showed histological signs of neural compromise. Patients with symptoms referable to L5 nerve compression for whom no proximal pathology is identified could warrant investigation of the more distal extraforaminal segment of this nerve.

Cervico-thoracic Interspinous Bursitis Associated with Bilateral Upper-extremity Numbness: A Case Report.

The authors describe a 48-year-old woman suffering from bilateral upper-extremity numbness and axial radiating pain. Magnetic resonance imaging revealed soft-tissue edema and enhancement surrounding the dorsal tip of the C7 spinous process. Excisional biopsy of the lesion revealed a mildly inflamed bursa, with no evidence of an active infection. Removal of the inflamed bursa resulted in complete resolution of the upper-extremity numbness and improvement in her neck pain. Although similar cases have been reported to be associated with rheumatologic conditions, most notably polymyalgia rheumatica (PMR), the current report underlines the presentation of radicular-like complaints associated with interspinous bursitis in the absence of other conditions affecting the musculoskeleton.

Advancement of Surgical Visualization Methods: Comparison Study Between Traditional Microscopic Surgery and a Novel Robotic Optoelectronic Visualization Tool for Spinal Surgery.

INTRODUCTION: The operating microscope (OM) has become instrumental in aiding surgeons during key microdissection with greater safety and detail. An exoscope offers similar detail with improved functionality and greater implications for live teaching and improved operating room flow. METHODS: Eleven senior neurosurgery residents and fellows performed unilateral, single-level laminotomies on fresh cadavers using an OM and exoscope. Three attending spine surgeons blinded for the visualization technique used then reviewed and graded each decompression. Data points gathered included time of procedure, grading of decompression (1-5), and complications, including dural tear, nerve root injury, and pars fracture. RESULTS: Operative times between the 2 systems were not significantly different (14.9 minutes OM vs. 15.6 minutes exoscope, P = 0.766). Despite high variability between evaluators in assessing complications and adequacy of decompression, there was no significant difference between either system. Postprocedural surveys indicated greater comfort with the exoscope, greater ease of use, and superior teaching potential for the exoscope over the standard OM. CONCLUSION: In our simulated operating room model, an exoscope is a valid alternative to the standard OM that affords the surgeon greater comfort with greater teaching potential while maintaining many of the microscope's benefits.

New Landmark for Localizing the Site of the Subdental Synchondrosis Remnant: Application to Discerning Pathology from Normal on Imaging.

OBJECTIVE: We hypothesized that the entry site of the basivertebral vein into the basivertebral foramen of C2 might localize the subdental synchondrosis between the odontoid process and body of C2, which may be helpful for odontoid fracture classification. METHODS: Twenty-five dry adult C2 specimens underwent thin-cut computed tomography and were sectioned sagittally. The basivertebral foramen was then correlated to internal bony anatomy. Fifty magnetic resonance images were reviewed, and the location of the subdental synchondrosis was determined. RESULTS: A basivertebral foramen was identified on the posterior surface of all dry C2 specimens. The openings were found at a distance of 30%-44% on an inferosuperior point along the vertical height of C2. For bony specimens with a subdental synchondrosis remnant (75%), entry of acupuncture needles into the basivertebral foramen was always directly at the level of the synchondrosis remnant. For magnetic resonance imaging (MRI), a subdental synchondrosis or its remnants were seen on all studies. The distance from the base of C2 to the subdental synchondrosis ranged from 9-13 mm. This equated to an inferosuperior point 32%-43% along the vertical height of C2. A strong correlation existed when comparing the location of the basivertebral foramen of bony specimens and the subdental synchondrosis location on MRI. CONCLUSIONS: The basivertebral foramen is a consistently present anatomic reference point for the subdental synchondrosis even if the latter cannot be seen on conventional radiographic imaging. Our MRI data might also be useful in helping differentiate lesions affecting C2 from normal subdental cartilaginous remnants that can be encountered on imaging.

Lateral Thoracic Osteoplastic Rib-Sparing Technique Used for Lateral Spine Surgery: Technical Note.

Of patients who have undergone lateral approaches to the thoracic spine, surgical site postoperative pain appears to be greater among those who have undergone transection and removal of a rib segment than those who have not. Therefore, techniques that conserve anatomical position and minimize tissue disruption would theoretically result in less pain and a quicker recovery. Herein, we describe a rib-sparing osteoplastic technique used when rib segments need to be displaced in order to create an unobscured corridor to the operative target. Our approach minimizes soft tissue disruption and restores the anatomical function of the rib. Based on our experience, these patients report less pain, mobilize earlier, and are discharged sooner than those who have had rib segments sacrificed as part of a lateral approach to the spine.

Unilateral Laminotomy with Bilateral Spinal Canal Decompression for Lumbar Stenosis: A Technical Note.

Lumbar stenosis has become one of the most common spinal pathologies and one that results in neurogenic claudication, back and leg pain, and disability. The standard procedure is still an open laminectomy, which involves wide muscle retraction and extensive removal of the posterior spinal structures. This can lead to instability and the need for additional spinal fusion. We present a systemized and detailed approach to unilateral laminotomy for bilateral decompression, which we believe is superior to the standard open laminectomy in terms of intraoperative visualization, postoperative stability, and degree of invasiveness.

Necrotizing Fasciitis: A Life-threatening Complication of Intraoperative Electromyography.

Intraoperative neurophysiological monitoring is a commonly used practice during spine surgery. Complications of electromyography (EMG) needle electrode placement are very uncommon. We present a patient who was infected with necrotizing fasciitis in her left thigh due to an EMG needle electrode during a two-stage complex spine procedure. This case demonstrates that providers should continue to meticulously adhere to protocol when inserting and removing EMG needles, but also be cognizant during postoperative observation of the possibility of infection caused by EMG needles.

Defining the Role of Cognitive Behavioral Therapy in Treating Chronic Low Back Pain: An Overview.

Study Design Narrative review of the literature. Objectives Determine if the term cognitive behavioral therapy (CBT) is useful in clinical care and research. What literature supports these variables being relevant to the experience of chronic pain? What effects of CBT in treating these factors have been documented? What methods and platforms are available to administer CBT? Methods Chronic low back pain (CLBP) is a complex neurologic disorder with many components. CBT refers to a broad family of therapies that address both maladaptive thoughts and behaviors. There are several ways to deliver it. CLBP was broken into five categories that affect the perception of pain, and the literature was reviewed to see the effects of CBT on these variables. Results The term cognitive behavioral therapy has little use in future research because it covers such a wide range of therapies. CBT should always be defined by the problem it is intended to solve. The format and method of delivery should be defined because they have implications for outcomes. They are readily available even at the primary care level. The effectiveness of CBT is unquestioned regarding its effectiveness in treating each of the variables that affect CLBP. It is unclear why it is not more widely implemented. Conclusions CBT represents a family of therapies that are effective for a wide range of problems, many of which coexist with and influence CLBP. Each of the variables can be improved with focused CBT. Early, widespread adoption of CBT in treating and preventing CLBP is recommended. Future research and clinical care should focus on strategies to operationalize these well-documented treatments utilizing a public health approach.

Chyloretroperitoneum following anterior spinal surgery.

Injury to the lymphatic channels is a rare and relatively unknown complication of anterior approaches to the lumbar spine and can cause fluid to build up in the retroperitoneal space, resulting in a lymphocele. If they enlarge sufficiently, these collections of chyle in the abdomen can cause pain and bowel ischemia, and can compress nearby organs. The authors report 4 cases in which anterior approaches to the lumbar spine were complicated by a postoperative retroperitoneal chylous fluid collection. They describe the anatomy of the lymphatic system and pathophysiology of this disease entity, review the sparse literature on this subject, and recommend a treatment algorithm. Maintaining a high index of suspicion for this clinical entity in patients who have recently undergone an anterior approach to the thoracic or lumbar spine is vital to avoid delays in diagnosis and treatment.

Early failure of metal-on-metal artificial disc prostheses associated with lymphocytic reaction: diagnosis and treatment experience in four cases.

STUDY DESIGN: Report of four collected cases. OBJECTIVE: The purpose of this report is to describe the presentation, diagnostic workup, treatment, and pathologic findings in four cases of lymphocytic reaction in patients receiving a metal-on-metal total disc replacement (TDR). SUMMARY OF BACKGROUND DATA: Metal-on-metal designs in hip arthroplasty have gained popularity because of decreased volumetric wear rates and theoretically increased implant longevity. Systemic metal ions produced have not been associated with adverse clinical sequelae, although there have been reports of local soft-tissue reactions leading to early prosthetic failure. Histologic evaluation in these cases suggested a cell-mediated delayed-type hypersensitivity reaction. Metal-on-metal bearings have also emerged in lumbar and cervical TDR. METHODS: This report is on four patients, from three centers, who underwent TDR, using a metal-on-metal implant, and later presented with symptoms that were determined to be due to lymphocytic reaction. Details of their symptoms, diagnostic work-up, treatment, and outcomes were compiled. RESULTS: All four patients initially had a good surgical outcome, followed by the onset and worsening of axial pain, and/or radicular symptoms months later. All patients had imaging findings of a mass lesion with neurologic impingement. All three of the lumbar patients underwent a decompressive posterior procedure before the eventual device removal and fusion. Intraoperatively, in all the lumbar cases, a thick, yellowish, avascular soft-tissue mass was found to be responsible for an epidural-mass effect on the thecal sac. In the cervical case, there was a gray-tinged soft-tissue response around the implant, suggestive of metallosis. Independent laboratory analysis confirmed a lymphocytic reaction to the implant. Three of the patients had a good outcome after the explant and revision surgery. The remaining patient continued to have residual symptoms related to the neural compression caused by the mass. CONCLUSIONS: In this group of patients from three centers, a metal-on-metal TDR resulted in a lymphocytic reaction causing subsequent failure of the surgery. This phenomenon has previously been recognized with metal bearings in hip arthroplasty. Surgeons using metal-on-metal TDRs should be aware of this possible occurrence.

Direct lateral lumbar interbody fusion for degenerative conditions: early complication profile.

STUDY DESIGN/SETTING: A community hospital prospective, nonrandomized chart review. March 2004 to December 2006, 58 patients were treated. Adverse events: new complaints and increasing length of stay limit early mobilization and require consultation with other physicians or reoperation. These formed the focus of the study. OBJECTIVE: Assess patient demographics and adverse events related to direct lateral lumbar approach. SUMMARY OF BACKGROUND DATA: Clinicians advocate anterior column support for lumbar conditions. Minimally invasive stabilization of lumbar spine via direct lateral approach gained popularity owing to perceived decrease in patient morbidity. METHODS: Mild or major adverse events during hospital stay or within 6 weeks of discharge were considered early complications and designated as medical, approach, or implant related. A historical cohort of open posterior spinal fusion patients was used for comparison. RESULTS: Forty-three female and 15 male patients with a mean age of 61 years formed the study group. Surgery performed included 38 single level, 19 2-level, and 1 3-level case. Adverse events occurred in 13 patients (22.4%); 8 events were approach, 3 medical, and 1 implant bone interface related. Major complications occurred in 5 patients (8.6%). Two patients (3.4%) with L4 nerve injury showed residual motor effects, at 1 year postoperatively. Significant differences were noted between single and 2-level cases; Estimated blood loss (EBL) and operative time. Open posterior fusion patients experienced greater operative time and increased EBL compared with minimally invasive cases. CONCLUSIONS: Major adverse events approximated 8.6% with approach-related complaints of nerve irritation nearing 3.4%. Mild complications occurred in 13.7% of patients. Meralgia paresthetica was a primary approach-related complaint. Most complaints significantly reduced by first postoperative visit. One patient (1.7%) had symptoms lasting over a year that did not adversely affect function. Significant finding related to exposure, that is, 1-versus 2-level cases. Overall morbidity reduction noted by EBL is considerably less compared with the historical cohort. Direct lateral lumbar interbody fusion has proven to be of value.