Incidence and Clinical Outcomes of Hypothyroidism in Patients Undergoing Spinal Fusion.

Background Hypothyroidism has been independently associated with the development of several comorbidities and is known to increase complication rates in non-spinal surgeries. However, there are limited data regarding the effects of hypothyroidism in major spine surgery. Therefore, we present the largest retrospective analysis evaluating outcomes in hypothyroid patients undergoing spinal fusion. Methods A retrospective review of the National Inpatient Sample (NIS) from 2004-2014 was performed. Patients with an International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) procedure code indicating spinal fusion (81.04-81.08, 81.34-81.38, 81.0x, 81.3x) were included. Patients with an ICD-9-CM diagnosis code indicating hypothyroidism (244.x) were compared to those without. Cervical and lumbar fusions were evaluated independently. Significant covariates in univariable logistic regression were utilized to construct multivariable models to analyze the effect of hypothyroidism on perioperative morbidity and mortality. Results A total of 4,149,125 patients were identified, of which 9.4% were hypothyroid. Although, hypothyroid patients had a higher risk of hematologic complications (lumbar - odds ratio [OR] 1.176, p < 0.0001; cervical - OR 1.162, p < 0.0001), they exhibited decreased in-hospital mortality (lumbar - OR .643, p < 0.0001; cervical - OR .606, p < 0.0001). Hypothyroid lumbar fusion patients also demonstrated decreased rates of perioperative myocardial infarction (MI) (OR .851, p < 0.0001). All these results were independent of patient gender. Conclusions Hypothyroid patients undergoing spinal fusion demonstrated lower rates of inpatient mortality and, in lumbar fusions, also had lower rates of acute MI when compared to their euthyroid counterparts. This suggests that hypothyroidism may offer protection against all-cause mortality and may be cardioprotective in the postoperative period for lumbar spinal fusions independent of patient gender.

Do-It-Yourself Augmented Reality Heads-Up Display (DIY AR-HUD): A Technical Note.

BACKGROUND: We present a "Do-It-Yourself" method to build an affordable augmented reality heads-up display system (AR-HUD) capable of displaying intraoperative images. All components are commercially available products, which the surgeons may use in their own practice for educational and research purposes. METHODS: Moverio BT 35-E smart glasses were connected to operating room imaging modalities (ie, fluoroscopy and 3D navigation platforms) via a high-definition multimedia interface (HDMI) converter, allowing for continuous high-definition video transmission. The addition of an HDMI transmitter-receiver makes the AR-HUD system wireless. RESULTS: We used our AR-HUD system in 3 patients undergoing instrumented spinal fusion. AR-HUD projected fluoroscopy images onto the surgical field, eliminating shift of surgeon focus and procedure interruption, with only a 40- to 100-ms delay in transmission, which was not clinically impactful. CONCLUSIONS: An affordable AR-HUD capable of displaying real-time information into the surgeon's view can be easily designed, built, and tested in surgical practice. As wearable heads-up display technology continues to evolve rapidly, individual components presented here may be substituted to improve its functionality and usability. Surgeons are in a unique position to conduct clinical testing in the operating room environment to optimize the augmented reality system for surgical use.

Effects of Body Mass Index on Perioperative Outcomes in Patients Undergoing Anterior Cervical Discectomy and Fusion Surgery.

OBJECTIVE: Obesity has become a public health crisis and continues to be on the rise. An elevated body mass index has been linked to higher rates of spinal degenerative disease requiring surgical intervention. Limited studies exist that evaluate the effects of obesity on perioperative complications in patients undergoing anterior cervical discectomy and fusion (ACDF). Our study aims to determine the incidence of obesity in the ACDF population and the effects it may have on postoperative inpatient complications. METHODS: The National Inpatient Sample was evaluated from 2004 to 2014 and discharges with International Classification of Diseases procedure codes indicating ACDF were identified. This cohort was stratified into patients with diagnosis codes indicating obesity. Separate univariable followed by multivariable logistic regression analysis were performed for the likelihood of perioperative inpatient outcomes among the patients with obesity. RESULTS: From 2004 to 2014, estimated 1,212,475 ACDFs were identified in which 9.2% of the patients were obese. The incidence of obesity amongst ACDF patients has risen dramatically during those years from 5.8% to 13.4%. Obese ACDF patients had higher inpatient likelihood of dysphagia, neurological, respiratory, and hematologic complications as well as pulmonary emboli, and intraoperative durotomy. CONCLUSION: Obesity is a well-established modifiable comorbidity that leads to increased perioperative complications in various surgical specialties. We present one of the largest retrospective analyses evaluating the effects of obesity on inpatient complications following ACDF. Our data suggest that the number of obese patients undergoing ACDF is steadily increasing and had a higher inpatient likelihood of developing perioperative complications.

Effects of menopausal state on lumbar decompression and fusion surgery.

Menopause leads to fluctuations in androgenic hormones which directly affect bone metabolism. Bone resorption, mineralization, and remodeling at fusion sites are essential in order to obtain a solid and biomechanically stable fusion mass. Bone metabolic imbalance seen in the postmenopausal state may predispose to fusion related complications. The aim of this study was to investigate fusion outcomes in lumbar spinal fusion surgery in women based on menopausal status. A retrospective analysis of all female patients who underwent posterior lumbar decompression and fusion at a single institution from 2013 to 2017 was performed. A total of 112 patients were identified and stratified into premenopausal (n = 25) and postmenopausal (n = 87) groups. Clinical and radiographic data was assessed at 1 year follow up. Postmenopausal patients had a higher rates of pseudarthrosis (11.63% vs 0%, p = 0.08), PJK (15.1% vs 4%, p = 0.14), and revision surgery (3.5% vs 0%, p = 0.35). The number of levels fused was associated with increased risk of pseudarthrosis (OR 1.4, p = 0.02); however, there was no association between age, hormonal use, prior tobacco use, or T-score. Age was associated with increased risk of developing PJK (OR = 1.11, p = 0.01); however, PJK was not associated with menopause, hormonal use, prior tobacco use, or T-score. Revision surgery was not associated with age, hormonal use, prior tobacco use, or T-score. This study suggests that postmenopausal women may be prone to have higher rates of pseudarthrosis, PJK and revision surgery, although our results were not statistically significant. Larger studies with longer follow up will help elucidate the true effects of menopause in spine surgery.

Short-term safety of tranexamic acid use in posterior cervical decompression and fusion surgery.

Posterior cervical decompression and fusion (PCDF) can result in substantial blood loss, leading to blood transfusions and associated complications, such as infections, hypotension and organ damage. The antifibrinolytic tranexamic acid (TXA), an inhibitor of the activation of plasminogen, has been shown to be beneficial in multiple surgical procedures without any apparent increase in postoperative complications. However, there are only few studies reporting TXA utilization in cervical spine surgery and there is currently no literature detailing the short-term safety of its use in this setting. The purpose of our study is to determine the safety profile of TXA in posterior cervical decompression and fusion. From January 2015 to April 2018, 47 patients were identified to have undergone PCDF, 19 with the utilization of a TXA protocol at our institution. The incidence of adverse events was evaluated in the perioperative period and at 1 month follow-up. Of 39 patients, Nineteen (49%) received TXA as per our instructional protocol and 20 (51%) did not. Post-operative blood was significantly reduced (453 ml vs 701 ml; p = 0.03) in the group that received TXA. There was also a significant reduction in duration of surgery associated with TXA use (269 min vs 328 min; p = 0.05). There were no complications on the first 30 days after surgical intervention on the TXA group. TXA use during PCDF is a safe, effective method to reduce postoperative blood loss. Considering the limited number of patients in this study, these results should be validated on a larger group of patients.

Reductions in length of stay, narcotics use, and pain following implementation of an enhanced recovery after surgery program for 1- to 3-level lumbar fusion surgery.

OBJECTIVELumbar fusion is typically associated with high degrees of pain and immobility. The implementation of an enhanced recovery after surgery (ERAS) approach has been successful in speeding the recovery after other surgical procedures. In this paper, the authors examined the results of early implementation of ERAS for lumbar fusion.METHODSBeginning in March 2018 at the authors' institution, all patients undergoing posterior, 1- to 3-level lumbar fusion surgery by any of 3 spine surgeons received an intraoperative injection of liposomal bupivacaine, immediate single postoperative infusion of 1-g intravenous acetaminophen, and daily postoperative visits from the authors' multidisciplinary ERAS care team. Non-English- or non-Spanish-speaking patients and those undergoing nonelective or staged procedures were excluded. Reviews of medical records were conducted for the ERAS cohort of 57 patients and a comparison group of 40 patients who underwent the same procedures during the 6 months before implementation.RESULTSGroups did not differ significantly with regard to sex, age, or BMI (all p > 0.05). Length of stay was significantly shorter in the ERAS cohort than in the control cohort (2.9 days vs 3.8 days; p = 0.01). Patients in the ERAS group consumed significantly less oxycodone-acetaminophen than the controls on postoperative day (POD) 0 (408.0 mg vs 1094.7 mg; p = 0.0004), POD 1 (1320.0 mg vs 1708.4 mg; p = 0.04), and POD 3 (1500.1 mg vs 2105.4 mg; p = 0.03). Postoperative pain scores recorded by the physical therapy and occupational therapy teams and nursing staff each day were lower in the ERAS cohort than in controls, with POD 1 achieving significance (4.2 vs 6.0; p = 0.006). The total amount of meperidine (8.8 mg vs 44.7 mg; p = 0.003) consumed was also significantly decreased in the ERAS group, as was ondansetron (2.8 mg vs 6.0 mg; p = 0.02). Distance ambulated on each POD was farther in the ERAS cohort, with ambulation on POD 1 (109.4 ft vs 41.4 ft; p = 0.002) achieving significance.CONCLUSIONSIn this very initial implementation of the first phase of an ERAS program for short-segment lumbar fusion, the authors were able to demonstrate substantial positive effects on the early recovery process. Importantly, these effects were not surgeon-specific and could be generalized across surgeons with disparate technical predilections. The authors plan additional iterations to their ERAS protocols for continued quality improvements.

Spondylodiscitis in end-stage renal disease: a systematic review.

OBJECTIVEDiscitis and osteomyelitis are seen in end-stage renal disease (ESRD) patients due to repeated vascular access for hemodialysis and urinary tract infections leading to recurrent bacteremia. Discitis and osteomyelitis are underdiagnosed due to the nonspecific initial presentation of back pain. In this article, we review the literature for better understanding of the problem and the importance of early diagnosis by primary care physicians and nephrologists. In addition, we discuss the decision-making, follow-up, management, and neurological outcomes.METHODSA detailed PubMed search was performed using the following terms: "end stage renal disease (ESRD)" and "chronic renal failure (CRF)," combined with "spine infections," "spondylodiscitis," "discitis," and "osteomyelitis." Search results were limited to articles written in English, case reports, and case series from 1973 to 2012. Editorials, reviews, and commentaries were excluded. Only studies involving human patients were included. The authors also included 4 patients from their own patient population.RESULTSA total of 30 articles met the inclusion criteria. Including the 4 patients from the authors' patient population, 212 patients with spine infections and maintenance dialysis were identified. The patients' ages ranged from 38 to 78 years. The duration of dialysis ranged from a few days to 16 years. The time from onset of back pain to diagnosis ranged from 3 days to 6 months. The most common causative organism was Staphylococcus aureus, followed by Staphylococcus epidermidis and gram-negative bacteria. Most of the patients were treated with antibiotics alone (76.8%), although surgery was indicated when patients presented with neurological deficits (p < 0.011). Approximately one-quarter of the patients developed neurological deficits, with devastating consequences. Fever and neurological deficits at presentation, culture positive for methicillin-resistant S. aureus, and age > 65 years were highly correlated with mortality in our analysis.CONCLUSIONSSeveral risk factors lead to failure of antibiotics and progression of disease in patients with ESRD. Challenges to diagnosis include vague presenting symptoms, co-existing destructive spondyloarthropathy, poor immune response, chronic elevations of inflammatory markers, and recurrent bacteremia. Infectious processes are more likely to cause permanent neurological deficits than transient deficits. The authors recommend close observation and serial imaging of these patients for early signs of neurological deficits. Any signs of disease progression will require aggressive surgical debridement.

A novel technique for stabilization of high-grade spondylolisthesis with transvertebral fusion without reduction.

Surgical treatment of high-grade spondylolisthesis and spondyloptosis is recommended in symptomatic patients, yet there exists much debate regarding the optimal surgical approach and the need for reduction. Similar to the Bohlman technique in that fixation is achieved across two vertebral endplates, we discuss a novel technique with the advantage of using bilateral threaded pedicle screws of large diameter and length instead of a single fibula allograft. Patients underwent posterior instrumented fusion without spondylolisthesis reduction using a novel technique placing pedicle screws with a transvertebral trajectory through the two end plates involved in the spondylolisthesis. Following screw placement, patients underwent decompression ±â€¯discectomy. Screws were connected to adjacent pedicle screws either in the upper adjacent vertebrae (i.e. L5) or the more rostral adjacent vertebrae (i.e. L4) if spinal alignment or instability necessitate including additional levels of fixation. Three patients were reviewed with ages of 67, 62, 58 years, operative times of 377-790 min, estimated blood loss 400-1050 cc, and follow-up times of 478-1082 days. There were no CSF leaks, intragenic neurologic deficits post-operatively, implant failures, revisions, or other systemic events. Two patients achieve radiographic fusion assessed by CT. At the time of final follow up, all patients were satisfied and essentially pain free. This one-stage technique offers the ability to manage local malalignment with a technique that inherently minimizes risk. The minimal complications and favorable outcomes make this technique an effective, efficient and safe procedure. Additional studies will focus on long term outcomes and should include larger patient samples.

Fish-Mouth Thoracic Fracture Fixation with Minimally Invasive Percutaneous Reduction: A Technical Note.

BACKGROUND: Surgical stabilization of thoracic spine fractures is recommended for unstable patterns, yet much debate exists regarding the best approach for reduction. The aim of this article was to report the outcome of a novel method for stabilization of a fish-mouth thoracic spine fracture. METHODS: A retrospective patient chart review was conducted. Data collected included blood loss, operative time, length of stay, perioperative complications, neurologic deficits, and secondary procedures. The patient underwent percutaneous reduction of a hyperextension injury to the thoracic spine. Sufficient reduction was achieved through a percutaneous approach, followed by sequential distraction of 1 rod with sequential locking of the contralateral rod to maintain deformity correction. Electrophysiologic monitoring was used during the procedure. RESULTS: Sufficient fracture reduction was achieved and evaluated on postoperative computed tomography. Operative time was 145 minutes, and estimated blood loss was 120 mL. There were no cerebrospinal fluid leaks, iatrogenic neurologic deficits, implant failures, other systemic events or revisions during the 8-month follow-up. CONCLUSIONS: This article describes the feasibility of using a novel model for reduction and stabilization of fish-mouth thoracic spine fracture with minimal soft tissue violation.

Transsphenoidal Approach for Pituitary Adenomas in Elderly Patients.

INTRODUCTION: With a rapidly expanding elderly population in the United States, the incidence of pituitary adenomas in elderly will continue to rise. In this study, we aim to evaluate the safety and efficacy of transsphenoidal endoscopic endonasal resection for pituitary adenomas in the elderly population. METHODS: A retrospective review of 131 consecutive patients who underwent transsphenoidal endoscopic endonasal resection for pituitary adenomas at the University of Miami Hospital between 2012 and 2016 was performed. Preoperative, intraoperative, and surgical outcomes were analyzed in elderly (>70 years) versus nonelderly (<70 years) patients. RESULTS: Of the 131 patients, 23 of them were >70 years (18%), of which 14 were septuagenarians and 9 were octogenarians. Elderly patients were more likely to present with vision loss (80.8% vs. 56.6%; P = 0.013) and larger tumors on imaging (2.7 ± 1.0 cm vs. 2.4 ± 1.3 cm; P = 0.042). Overall surgical and endocrinologic outcomes between the 2 groups were similar. However, patients <70 years old were more likely to have a gross total resection (86.7% vs. 65.4%; P = 0.011), as well as transient diabetes insipidus (54.3% vs. 26.9% P = 0.012) and intraoperative cerebrospinal fluid leak (83.5% vs. 58.5%; P = 0.013). However, permanent postoperative complication rates were similar including rate of permanent diabetes insipidus (4.3% elderly vs. 12.1% adult), cerebrospinal fluid leak (8.7% elderly vs. 8.4% adult), and meningitis (4.3% elderly vs. 2.8% adult). There were no medical complications or deaths in our cohort. CONCLUSION: The transsphenoidal endoscopic endonasal approach can be a safe and effective technique for resection of pituitary adenomas in patients >70 years old with appropriate patient selection.

The History of and Controversy over Kambin's Triangle: A Historical Analysis of the Lumbar Transforaminal Corridor for Endoscopic and Surgical Approaches.

The transforaminal corridor in the lumbar spine allows access to the traversing and exiting nerve roots, the thecal sac, and the intervertebral disc space. Surgeons performing midline and minimally invasive approaches for lumbar interbody fusion access the disc space within the boundaries created by the exiting root of a segment and the traversing root after a complete facetectomy and removal of the pars interarticularis and lamina. Endoscopic surgeons and interventional pain management physicians approach the lumbar segment through a similar corridor, but with the bony anatomy intact. Although the boundaries of the corridor may seem the same, the angle of the trajectory and the bone work between the two differ. The overlap between these 2 distinct access corridors has led to an openhanded application of the term Kambin's triangle. Initially described for endoscopic approaches to the lumbar spine for microdiscectomy, this working triangle has been grafted into the transforaminal lumbar interbody fusion literature. Given the similarities between these corridors, it is understandable how the lines of this nomenclature have blurred. The result has been an interchangeable application of the term Kambin's triangle for a variety of procedures in the spine literature. The objective of the current work is to add clarity to the various lumbar transforaminal corridors. The term Kambin's triangle should be limited to percutaneous access to the disc space for endoscopic procedures in the intact spine and should not be applied to transforaminal lumbar interbody fusion after laminectomy and facetectomy. Instead, the term expanded transforaminal corridor should be applied.

The Utility of Magnetic Resonance Imaging-compatible Pacemakers in Neurosurgical Patients.

Artificial implantable pacemakers have long been a challenge to neurosurgeons seeking to perform advanced diagnostic imaging on their patients. Unfortunately, while the use of implantable pacemakers has been a life-saving advance for those with cardiac arrhythmias, they also often prevent these patients from undergoing magnetic resonance imaging (MRI). There have been multiple reported cases of pacemaker failure in the context of MRI use. Recent technological advances, however, have allowed the development of pacemakers that are not affected by the MRI scanner. Similar technology has also been applied to the development of MRI-compatible spinal cord stimulators and other neurostimulation devices. In this paper, we discuss four specific neurosurgical cases where the use of MRI was critical for diagnostic and therapeutic decision-making. Current non-MRI-compatible pacemakers were exchanged for MRI-compatible pacemaker technology with some associated cost and risk. The diagnostic cranial and spinal MRIs subsequently obtained were critical for forging the ensuing neurosurgical care. Based on these cases, we extrapolate the importance of MRI-compatible pacemakers to society at large and advocate for the use of such devices in all patients going forward.

Inpatient Outcomes After Elective Lumbar Spinal Fusion for Patients with Human Immunodeficiency Virus in the Absence of Acquired Immunodeficiency Syndrome.

BACKGROUND: To our knowledge, no prior study has evaluated outcomes after elective lumbar spinal surgery in human immunodeficiency virus (HIV) patients without acquired immunodeficiency syndrome (AIDS). This review investigated the impact of HIV-positive status (without AIDS) on outcomes after elective lumbar fusion for degenerative disc disease (DDD). METHODS: Adult patients registered in the Nationwide Inpatient Sample (2002-2011) undergoing elective lumbar fusion for DDD were extracted. Multivariable regression techniques were used to explore the association of HIV positivity with outcomes after lumbar fusion. RESULTS: This cohort included 612,000 hospitalizations (0.07% were HIV positive) of lumbar fusion for DDD. Compared with HIV-negative patients undergoing lumbar fusion, HIV-positive patients were younger (47 vs. 55 years), male (61% vs. 42%), largely insured by Medicare (30% vs. 5%), and had higher rates of chronic obstructive pulmonary disease (23.7% vs. 14.6%) (all P < 0.001) but had lower rates of obesity, hypertension, and diabetes (all P < 0.001). Multivariable models demonstrated HIV positivity to be associated with higher odds for an adverse event (odds ratio [OR], 1.92; P < 0.001), in-hospital mortality (OR, 39.91; P < 0.001), wound complications (OR, 2.60; P = 0.004), respiratory (OR, 5.43; P < 0.001) and neurologic (OR, 1.96; P = 0.039) complications, and higher costs (7.1% higher; P = 0.011) compared with non-HIV patients. There were no differences in thromboembolic events, cardiac or gastrointestinal complications, discharge disposition, or length of stay. CONCLUSIONS: Even in this selected cohort of well-controlled HIV patients, there were high complications, with concerning rates of death and respiratory complications. These data shed new light on elective spine surgery in HIV patients and may influence the treatment algorithm of surgeons who are familiar with older papers.

Impact of Psychiatric Comorbidities on Short-Term Outcomes Following Intervention for Lumbar Degenerative Disc Disease.

STUDY DESIGN: Retrospective, observational cohort study. OBJECTIVE: To investigate the impact of psychiatric diseases on short-term outcomes in patients undergoing fusion surgery for lumbar degenerative disc disease (LDDD). SUMMARY OF BACKGROUND DATA: Limited literature exists on the prevalence and impact of psychiatric comorbidities on outcomes in patients undergoing surgery for LDDD. METHODS: Adult patients (>18 yr) registered in the Nationwide Inpatient Sample database (2002-2011) and undergoing an elective spine fusion for LDDD that met inclusion criteria formed the study population. Defined primary outcome measures were discharge disposition, length of stay, hospitalization cost, and short-term postsurgical complications (neurological, respiratory, cardiac, gastrointestinal, wound complication and infections, venous thromboembolism, and acute renal failure). Multivariable regression techniques were used to explore the association of psychiatric comorbidities on short-term outcomes by adjusting for patient demographics, clinical, and hospital characteristics. RESULTS: Of the 126,044 adult patients undergoing fusion surgery for LDDD (mean age: 54.91 yr, 58% female) approximately 18% had a psychiatric disease. Multivariable regression analysis revealed patients with psychiatric disease undergoing fusion surgery have higher likelihood for unfavorable discharge (odds ratio [OR] 1.41; 95% confidence interval [CI] 1.35-1.47; P < 0.001), length of stay (OR 1.03; 95% CI 1.02-1.04; P < 0001), postsurgery neurologic complications (OR 1.25; 95% CI 1.13-1.37; P < 0.001), venous thromboembolic events (OR 1.38 95% CI 1.26-1.52; P < 0.001), and acute renal failure (OR 1.17; 95% CI 1.01-1.37; P = 0.040). Patients with psychiatric disease were also associated to have higher hospitalization cost (6.3% higher; 95% CI: 5.6%-7.1%; P < 0.001) compared to those without it. CONCLUSION: Our study quantifies the estimates for presence of concomitant psychiatric comorbid conditions on short outcomes in patients undergoing fusions for LDDD. The data provide supporting evidence for adequate preoperative planning and postsurgical care including consultation for mental health for favorable outcomes. LEVEL OF EVIDENCE: 4.

Transdural approach to resection of retro-odontoid cysts in elderly patients: report of 3 cases.

Retro-odontoid cysts that arise from the tectorial membrane are uncommon lesions that can occur in elderly patients. They arise secondary to degenerative changes, including calcium pyrophosphate deposition within the ligaments. Surgical treatment is indicated when these lesions result in intractable pain, instability, and/or myelopathy. Several surgical techniques to treat this condition exist, but the optimal approach in elderly patients with comorbidities remains controversial. Here, the authors present a case series of 3 patients who underwent successful resection of a retro-odontoid lesion performed through a transdural approach. The patients were 70, 81, and 74 years old and presented with symptoms of cervical myelopathy. In consideration of their advanced age and the location of their lesion, resection via a posterior approach was considered. A 1- to 2-cm suboccipital craniectomy and C-1 and partial C-2 laminectomy were performed. These lesions could not be accessed via an extradural posterolateral approach, and so a transdural approach was performed. In the first 2 patients, a preexisting deformity prompted an instrumented fusion. In the third patient, only a lesion resection was performed. In each case, the dural opening was made using a paramedian ipsilateral-sided incision, and the lesion was resected through an incision in the anterior dura mater. Only the posterior dura was closed primarily. MR imaging evidence of excellent spinal cord decompression was evident in follow-up examinations. Transdural resection of retro-odontoid cysts is a viable option for treating asymmetrical ventral extradural cysts. Results from this case series suggest that such an approach is safe and feasible and can provide an alternative to open or endoscopic anterior transpharyngeal approaches.

The Role of Dynamic Magnetic Resonance Imaging in Cervical Spondylotic Myelopathy.

Dynamic spinal cord compression has been investigated for several years, but until the advent of open MRI, the use of dynamic MRI (dMRI) did not gain popularity. Several publications have shown that cervical cord compression is both static and dynamic. On many occasions the evaluation of cervical spondylotic myelopathy (CSM) is straightforward, but patients are frequently encountered with a significantly worse clinical examination than would be suggested by radiological images. In this paper, we present an extensive review of the literature in order to describe the importance of dMRI in various settings and applications. A detailed literature review was performed in the Medline and Pubmed databases using the terms "cervical spondylotic myelopathy", "dynamic MRI", "kinetic MRI", and "myelomalalcia" for the period of 1980-2016. The study was limited to English language, human subjects, case series, retrospective studies, prospective reports, and clinical trials. Reviews, case reports, cadaveric studies, editorials, and commentaries were excluded. The literature search yielded 180 papers, 19 of which met inclusion criteria. However, each paper had evaluated results and outcomes in different ways. It was not possible to compile them for meta-analysis or pooled data evaluation. Instead, we evaluated individual studies and present them for discussion. We describe a number of parameters evaluated in 2661 total patients, including dynamic changes to spinal cord and canal dimensions, transient compression of the cord with changes in position, and the effects of position on the intervertebral disc. dMRI is a useful tool for understanding the development of CSM. It has found several applications in the diagnosis and preoperative evaluation of many patients, as well as certain congenital dysplasias and Hirayama disease. It is useful in correlating symptoms with the dynamic changes only noted on dMRI, and has reduced the incidence of misdiagnosis of myelopathy.

Minimally-Invasive versus Conventional Repair of Spondylolysis in Athletes: A Review of Outcomes and Return to Play.

Spondylolysis from pars fracture is a common injury among young athletes, which can limit activity and cause chronic back pain. While current literature has examined the relative benefits of surgical and conservative management of these injuries, no study has yet compared outcomes between conventional direct repair of pars defects and modern minimally invasive procedures. The goals of surgery are pain resolution, return to play at previous levels of activity, and a shorter course of recovery. In this review, the authors have attempted to quantify any differences in outcome between patients treated with conventional or minimally invasive techniques. A literature search was performed of the PubMed database for relevant articles, excluding articles describing conservative management, traumatic injury, or high-grade spondylolisthesis. Articles included for review involved young athletes treated for symptomatic spondylolysis with either conventional or minimally invasive surgery. Two independent reviewers conducted the literature search and judged articles for inclusion. All studies were classified according to the North American Spine Society standards. Of the 116 results of our initial search, 16 articles were included with a total of 150 patients. Due to a paucity of operative details in older studies and inconsistencies in both clinical methods and reporting among most articles, little quantitative analysis was possible. However, patients in the minimally invasive group did have significantly higher rates of pain resolution (p<0.001). Short recovery times were also noted in this group. Both groups experienced low complication rates, and the majority of patients returned to previous levels of activity. Surgical repair of spondylolysis in young athletes is a safe and practical therapy. Current literature suggests that while conventional repair remains effective, minimally invasive procedures better clinical outcomes. We await further data to conduct a more thorough quantitative analysis of these techniques.