Complications associated with the Dynesys dynamic stabilization system: a comprehensive review of the literature.

The Dynesys dynamic stabilization system is an alternative to rigid instrumentation and fusion for the treatment of lumbar degenerative disease. Although many outcomes studies have shown good results, currently lacking is a comprehensive report on complications associated with this system, especially in terms of how it compares with reported complication rates of fusion. For the present study, the authors reviewed the literature to find all studies involving the Dynesys dynamic stabilization system that reported complications or adverse events. Twenty-one studies were included for a total of 1166 patients with a mean age of 55.5 years (range 39-71 years) and a mean follow-up period of 33.7 months (range 12.0-81.6 months). Analysis of these studies demonstrated a surgical-site infection rate of 4.3%, pedicle screw loosening rate of 11.7%, pedicle screw fracture rate of 1.6%, and adjacent-segment disease (ASD) rate of 7.0%. Of studies reporting revision surgeries, 11.3% of patients underwent a reoperation. Of patients who developed ASD, 40.6% underwent a reoperation for treatment. The Dynesys dynamic stabilization system appears to have a fairly similar complication-rate profile compared with published literature on lumbar fusion, and is associated with a slightly lower incidence of ASD.

The Clinical Correlations between Diabetes, Cigarette Smoking and Obesity on Intervertebral Degenerative Disc Disease of the Lumbar Spine.

STUDY DESIGN: Retrospective analysis of a nationwide private insurance database. Chi-square analysis and linear regression models were utilized for outcome measures. PURPOSE: The purpose of this study was to investigate any relationship between lumbar degenerative disc disease, diabetes, obesity and smoking tobacco. OVERVIEW OF LITERATURE: Diabetes, obesity, and smoking tobacco are comorbid conditions known to individually have effect on degenerative disc disease. Most studies have only been on a small populous scale. No study has yet to investigate the combination of these conditions within a large patient cohort nor have they reviewed the combination of these conditions on degenerative disc disease. METHODS: A retrospective analysis of insurance billing codes within the nationwide Humana insurance database was performed, using PearlDiver software (PearlDiver, Inc., Fort Wayne, IN, USA), to identify trends among patients diagnosed with lumbar disc degenerative disease with and without the associated comorbidities of obesity, diabetes, and/or smoking tobacco. Patients billed for a comorbidity diagnosis on the same patient record as the lumbar disc degenerative disease diagnosis were compared over time to patients billed for lumbar disc degenerative disease without a comorbidity. There were no sources of funding for this manuscript and no conflicts of interest. RESULTS: The total number and prevalence of patients (per 10,000) within the database diagnosed with lumbar disc degenerative disease increased by 241.4% and 130.3%, respectively. The subsets of patients within this population who were concurrently diagnosed with either obesity, diabetes, tobacco use, or a combination thereof, was significantly higher than patients diagnosed with lumbar disc degenerative disease alone (p <0.05 for all). The number of patients diagnosed with lumbar disc degenerative disease and smoking rose significantly more than patients diagnosed with lumbar disc degenerative disease and either diabetes or obesity (p <0.05). The number of patients diagnosed with lumbar disc degenerative disease, smoking and obesity rose significantly more than the number of patients diagnosed with lumbar disc degenerative disease and any other comorbidity alone or combination of comorbidities (p <0.05). CONCLUSIONS: Diabetes, obesity and cigarette smoking each are significantly associated with an increased diagnosis of lumbar degenerative disc disease. The combination of smoking and obesity had a synergistic effect on increased rates of lumbar degenerative disc disease. Patient education and preventative care is a vital goal in prevention of degenerative disc disease within the general population.

Neurocutaneous melanosis presenting with hydrocephalus. Case report and review of the literature.

Neurocutaneous melanosis (NCM) is a rare congenital neurocutaneous syndrome characterized by large or multiple congenital melanocytic nevi and benign or malignant melanocytic tumors of the leptomeninges. The authors report the case of a 5-month-old girl with congenital giant melanocytic nevi who presented with symptomatic hydrocephalus. A right frontal ventriculostomy was performed in the patient. Magnetic resonance imaging demonstrated melanocyte accumulation within the hippocampi, medulla, and cerebellum. Cerebrospinal fluid cytology revealed no presence of melanocytes. A ventriculoperitoneal shunt was placed; the patient's neurological condition improved and she was discharged home in good condition. The diagnosis of neurocutaneous melanosis should be considered in a case in which an infant or child presents with hydrocephalus and either large or multiple (> or = 3) congenital melanocytic nevi. Although our patient's neurological status improved following treatment for hydrocephalus, there is no definitive therapy for NCM and symptomatic patients have a poor prognosis. Our case illustrates to the neurosurgeon the importance of recognizing the likelihood of underlying pathological conditions of the central nervous system in a child with cutaneous melanocytic nevi.

Novel application of pre-operative vertebral body embolization to reduce intraoperative blood loss during a three-column spinal osteotomy for non-oncologic spinal deformity.

Three column osteotomies (3CO) of the lumbar spine are powerful corrective procedures used in the treatment of kyphoscoliosis. Their efficacy comes at the cost of high reported complication rates, notably significant estimated blood loss (EBL). Previously reported techniques to reduce EBL have had modest efficacy. Here we describe a potential technique to decrease EBL during pedicle subtraction osteotomy (PSO) of the lumbar spine by means of pre-operative vertebral body embolization - a technique traditionally used to reduce blood loss prior to spinal column tumor resection. We present a 62-year-old man with iatrogenic kyphoscoliosis who underwent staged deformity correction. Stage 1 involved thoracolumbar instrumentation followed by transarterial embolization of the L4 vertebral body through bilateral segmental arteries. A combination of polyvinyl alcohol particles and Gelfoam (Pfizer, New York, NY, USA) were used. Following embolization there was decreased angiographic blood flow to the small vessels of the L4 vertebral body, while the segmental arteries remained patent. Stage 2 consisted of an L4 PSO and fusion. The EBL during the PSO procedure was 1L, which compared favorably to that during previous PSO at this institution as well as to quantities reported in previous literature. There have been no short term (5 month follow-up) complications attributable to the vertebral body embolization or surgical procedure. Although further investigation into this technique is required to better characterize its safety and efficacy in reducing EBL during 3CO, we believe this patient illustrates the potential utility of pre-operative vertebral embolization in the setting of non-oncologic deformity correction surgery.

CT navigated lateral interbody fusion.

Lateral interbody fusion techniques are heavily reliant on fluoroscopy for retractor docking and graft placement, which expose both the patient and surgeon to high doses of radiation. Use of image-guided technologies with CT-based images, however, can eliminate this radiation exposure for the surgeon. We describe the surgical technique of performing lateral lumbar interbody fusion using CT navigation.

Predicting ideal spinopelvic balance in adult spinal deformity.

OBJECTIVE: Spinopelvic balance is based on the theory that adjacent segments of the spine are related and influenced by one another. By understanding the correlation between the thoracolumbar spine and the pelvis, a concept of spinopelvic balance can be applied to adult deformity. The purpose of this study was to develop a mathematical relationship between the pelvis and spine and apply it to a population of adults who had undergone spinal deformity surgery to determine whether patients in spinopelvic balance have improved health measures. METHODS: Using values published in the literature, a mathematical relationship between the spine and pelvis was derived where pelvic incidence (PI) was divided by the sum of the lumbosacral lordosis (LL; T12-S1) plus the main thoracic kyphosis (TK; T4-12). The result was termed the spinopelvic constant (r): r = PI/(LL + TK). This was performed in patients in 2 age groups previously defined in the literature as "adult" (18-60 years of age) and "geriatric" (> 60 years). The equation was then constructed to relate an individual's measured PI to his or her predicted thoracolumbar curvature (LL + TK)(p) based on the age-specific spinopelvic constant: (LL + TK)(p) = r/PI. A retrospective review was then performed using cases involving patients who had undergone spine deformity surgery and were enrolled in our spinal deformity database. Sagittal balance, PI, and the sum of the main thoracic and lumbar curves were measured. The difference between the predicted sum of the regional curves (LL + TK)(p), based on the individual's measured PI and the age-specific spinopelvic constant, and the measured sum of the regional curves (LL + TK)(m) was then calculated to determine the degree of spinopelvic imbalance. Health status measures were then compared. RESULTS: Using the formula r = PI/(TK = LL) and normative values in the literature, the adult spinopelvic constant was calculated to be -2.57, and the geriatric constant -5.45. For the second portion of the study, 41 patients met inclusion criteria (13 classified as nongeriatric adults and 28 as geriatric patients). Application of these constants found a statistically significant decline in almost all outcome categories when the spinopelvic balance showed at least 10° of kyphosis more than predicted. While not statistically significant, the trend was that better outcomes were associated with a spinopelvic balance within 0 to +10° of the predicted value. The final analysis compared and separated outcomes from sagittal balance and spinopelvic balance. For patients to be considered in sagittal balance, they must be within 50 mm (± 50 mm) of neutral. For patients to be considered in spinopelvic balance, they must be within ± 10° of predicted spinopelvic balance. Patients in both sagittal and spinopelvic balance have statistically significant better outcomes than those in neither sagittal nor spinopelvic balance. Except for the mean SF-12 PCS (12-Item Short-Form Health Survey Physical Component Summary), there were no significant differences between those that were either in sagittal or spinopelvic balance, but not the other. CONCLUSIONS: Restoring a normative relationship between the spine and the pelvis during adult deformity correction may play an important role in determining surgical outcomes in these patients independent of sagittal balance.