What Is the Fate of Pseudarthrosis Detected 1 Year After Anterior Cervical Discectomy and Fusion?

Spine 2018;43:E23–E28

Objective. To investigate the consequences and appropriate management of pseudarthrosis after anterior cervical discectomy and fusion (ACDF).

Summary of Background Data. Pseudarthrosis is a frequent complication of ACDF and causes unsatisfactory results. Little is known about long-term prognosis of detecting pseudarthrosis 1 year after ACDF.

Methods. Eighty-nine patients with a minimum 2-year followup were included. ACDF surgery using allograft and plating was performed: single-level in 51 patients, two-level in 26 patients, and three-level in 12 patients. Presence of pseudarthrosis was evaluated 1 year postoperatively and then the nonunion segments were re-evaluated 2 years postoperatively. Demographic data were assessed to identify the risk factors associated with pseudarthrosis. A visual analogue scale for neck/arm pain and the Neck Disability Index were analyzed preoperatively and at 1 and 2 years postoperatively.

Results. Pseudarthrosis was detected in 29 patients (32.6%) 1 year postoperatively: 15of 51 patients after single-level surgery, 9 of 26 patients after two-level surgery, and 5 of 12 patients after three-level surgery. Only eight patients showed persistent nonunion at 2 years: 3 of 15 patients after single-level surgery, 3 of 9 after two-level surgery, and 2 of 5 after three-level surgery. The remaining 21 patients (72.4%) achieved bony fusion 2 years postoperatively without any intervention. Patients who underwent two-level or three-level ACDF had a significantly higher pseudarthrosis rate than those who underwent single-level ACDF, with odds ratios of 1.844 and 3.147, respectively. The improvements in visual analogue scale for neck pain and Neck Disability Index scores in the persistent nonunion group were significantly lower than those in the final union group at 2 years.

Conclusion. Patients with pseudarthrosis detected 1 year postoperatively may be observed without any intervention because approximately 70% of them will eventually fuse by the 2-year point. Early revision could, however, be considered if the pseudarthrosis is associated with considerable neck pain after multilevel ACDF.

Level of Evidence: 3

Different Risk Factors of Proximal Junctional Kyphosis and Proximal Junctional Failure Following Long Instrumented Fusion to the Sacrum for Adult Spinal Deformity

Neurosurgery 80:279–286, 2017

The failure modes, time to development, and clinical relevance are known to differ between proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). However, there are no reports that study the risk factors of PJK and PJF separately.

OBJECTIVE: The aim of this study was to investigate the risk factors for PJK and PJF separately.

METHODS: A retrospective study of 160 consecutive patients who underwent a long instrumented fusion to the sacrum for adult spinal deformity with a minimum follow-up of years was conducted. A separate survivorship analysis of PJK and PJF was performed using the Cox proportional hazards model for the 3 categorical parameters of surgical, radiographic, and patient factors.

RESULTS: PJK developed in 27 patients (16.9%) and PJF in 29 patients (18.1%). The median survival time was 17.0 months for PJK and 3.0 months for PJF. Multivariate analyses revealed that a high body mass index was an independent risk factor for PJK (hazard ratio [HR] = 1.179), whereas the significant risk factors for PJF were older age, the presence of osteoporosis, the uppermost instrumented vertebra level at T11-L1, and a greater preoperative sagittal vertical axis (HR = 1.082, 6.465, 5.236, and 1.017, respectively). A large correction of sagittal deformity was shown to be a risk factor for PJF on univariate analyses, but not on multivariate analyses.

CONCLUSION: PJK developed at a median of 17 months and PJF at a median of 3 months. A high body mass index was an independent risk factor for PJK, whereas older age, osteoporosis, uppermost instrumented vertebra level at the thoracolumbar junction, and greater preoperative sagittal vertical axis were risk factors for PJF.


Morphological and clinical risk factors for the rupture of anterior communicating artery aneurysms

Anterior communicating artery aneurysm rupture

J Neurosurg 118:978–983, 2013

Patients with ruptured anterior communicating artery (ACoA) aneurysms have historically been observed to have poor neuropsychological outcomes, and ACoA aneurysms have accounted for a higher proportion of ruptured than unruptured aneurysms. Authors of this study aimed to investigate the morphological and clinical characteristics predisposing to ACoA aneurysm rupture.

Methods. Data from 140 consecutive patients with ACoA aneurysms managed at the authors’ facility between July 2003 and November 2011 were retrospectively reviewed. Patients with (78) and without (62) aneurysm rupture were divided into groups, and morphological and clinical characteristics were compared. Morphological characteristics were evaluated based on 3D CT angiography and included aneurysm location, dominance of the A1 portion of the anterior cerebral artery, direction of the aneurysm dome around the ACoA, aneurysm bleb(s), size of the aneurysm and its neck, aneurysm–parent artery angle, and existence of other intracranial unruptured aneurysms.

Results. Patients with ruptured ACoA aneurysms were significantly younger (a higher proportion were younger than 60 years of age) than those with unruptured lesions, and a significantly smaller proportion had hypercholesterolemia. A significantly larger proportion of patients with ruptured aneurysms showed an anterior direction of the aneurysm dome around the ACoA, had a bleb(s), and/or had an aneurysm size ≥ 5 mm. Multivariate logistic regression analysis showed that an anterior direction of the aneurysm dome around the ACoA (OR 6.0, p = 0.0012), the presence of a bleb(s) (OR 22, p < 0.0001), and an aneurysm size ≥ 5 mm (OR 3.16, p = 0.035) were significantly associated with ACoA aneurysm rupture.

Conclusions. Findings in the present study demonstrated that the anterior projection of an ACoA aneurysm may be related to rupturing. The authors would perhaps recommend treatment to patients with unruptured ACoA aneurysms that have an anterior dome projection, a bleb(s), and a size ≥ 5 mm.

Independent predictors for recurrence of chronic subdural hematoma

Acta Neurochir (2012) 154:1541–1548 DOI 10.1007/s00701-012-1399-9

Chronic subdural hematoma is characterized by blood in the subdural space that evokes an inflammatory reaction. Numerous factors potentially associated with recurrence of chronic subdural hematoma have been reported, but these factors have not been sufficiently investigated. In this study, we evaluated the independent risk factors of recurrence.

Methods We analyzed data for 420 patients with chronic subdural hematoma treated by the standard surgical procedure for hematoma evacuation at our institution.

Results Ninety-two (21.9 %) patients experienced at least one recurrence of chronic subdural hematoma during the study period. We did not identify any significant differences between chronic subdural hematoma recurrence and current antiplatelet therapy. The recurrence rate was 7 % for the homogeneous type, 21 % for the laminar type, 38 % for the separated type, and 0 % for the trabecular type. The rate of recurrence was significantly lower in the homogeneous and trabecular type than in the laminar and separated type. We performed a multivariate logistic regression analysis and found that postoperative midline shifting (OR, 3.6; 95 % CI, 1.618-7.885; p00.001), diabetes mellitus (OR, 2.2; 95 % CI, 1.196-3.856; p=0.010), history of seizure (OR, 2.6; 95 % CI, 1.210-5.430; p=0.014), width of hematoma (OR, 2.1; 95 % CI, 1.287-3.538; p=0.003), and anticoagulant therapy (OR, 2.7; 95 % CI, 1.424-6.960; p=0.005) were independent risk factors for the recurrence of chronic subdural hematoma.

Conclusions We have shown that postoperative midline shifting (≥5 mm), diabetes mellitus, preoperative seizure, preoperative width of hematoma (≥20 mm), and anticoagulant therapy were independent predictors of the recurrence of chronic subdural hematoma. According to internal architecture of hematoma, the rate of recurrence was significantly lower in the homogeneous and the trabecular type than the laminar and separated type.

Perioperative mortality after lumbar spinal fusion surgery: an analysis of epidemiology and risk factors

Eur Spine J (2012) 21:1633–1639 DOI 10.1007/s00586-012-2298-8

Study design Analysis of the Nationwide Inpatient Sample (NIS) from 1998 to 2008.

Objective To analyze the most recent available and nationally representative data for risk factors contributing to in-hospital mortality after primary lumbar spine fusion.

Summary of background data The total number of lumbar spine fusion surgeries has increased dramatically over the past decades. While the field of spine fusion surgery remains highly dynamic with changes in perioperative care constantly affecting patient care, recent data affecting rates and risk for perioperative mortality remain very limited.

Methods We obtained the NIS from the Hospital cost and utilization project. The impact of patient and health care system related demographics, including various comorbidities as well as postoperative complications on the outcome of in-hospital mortality after spine fusion were studied. Furthermore, we analyzed the timing of in-hospital mortality.

Results An estimated total of 1,288,496 primary posterior lumbar spine fusion procedures were performed in the US between 1998 and 2008. The average mortality rate for lumbar spine fusion surgery was 0.2 %. Independent risk factors for in-hospital mortality included advanced age, male gender, large hospital size, and emergency admission. Comorbidities associated with the highest in-hospital mortality after lumbar spine fusion surgery were coagulopathy, metastatic cancer, congestive heart failure and renal disease. Most lethal complications were cerebrovascular events, sepsis and pulmonary embolism. Furthermore, we demonstrated that the timing of death occurred relatively early in the in-hospital period with over half of fatalities occurring by postoperative day 9.

Conclusion This study provides nationally representative information on risk factors for and timing of perioperative mortality after primary lumbar spine fusion surgery. These data can be used to assess risk for this event and to develop targeted intervention to decrease such risk.

Risk Factors of Sagittal Decompensation After Long Posterior Instrumentation and Fusion for Degenerative Lumbar Scoliosis

SPINE Volume 35, Number 17, pp 1595–1601.

Study Design. A retrospective study of clinical results of operative treatment for degenerative lumbar scoliosis.

Objective. To determine the risk factors of sagittal decompensation after long instrumentation and fusion to L5 or S1. Summary of Background Data. Little is known about the risk factors for sagittal decompensation, which was defined in this study as sagittal C7 plumb falling anterior 8 cm from the posterosuperior corner of the sacrum.

Methods. Forty-five patients (mean age: 64.4 year) with adult degenerative lumbar scoliosis were reviewed retrospectively with a minimum 2 years. The mean number of levels fused was 6.1  1.6 segments. The upper instrumented vertebra ranged from T9 to L2. The lower instrumented vertebra was L5 and S1 in 24 and 21 patients, respectively.

Results. Sagittal decompensation (SD) developed in 19 patients. The most significant risk factors of SD were preoperative sagittal imbalance and high pelvic incidence. The preoperative sagittal C7 plumb was more positive (67.9 mm) in the decompensation group than in the balance group (37.0 mm) (P = 0.002). There was a significant difference in pelvic incidence between 61.7° in the decompensation and 54.9° in the balance group (P = 0.01). The preoperative lumbar lordosis was hypolordotic in the decompensation group, however, it was not found to be a risk factor. Pseudarthrosis was identified at the lumbosacral junction in 5 patients, and 4 of them (80%) had SD. SD developed in 55% of patients who had loosening of the distal screws and 50% of patients with hypolordotic lumbar fusion. Distal adjacent segment disease was more likely to cause SD than proximal adjacent segment disease.

Conclusion. Sagittal decompensation is common after long posterior instrumentation and fusion for degenerative lumbar scoliosis. It is mostly associated with complications at the distal segments, including pseudarthrosis and implant failure at the lumbosacral junction. Restoration of optimal lumbar lordosis and secure lumbosacral fixation is necessary especially in patients with preoperative sagittal imbalance and high pelvic incidence in order to prevent sagittal decompensation after surgery. Key words: adult spinal deformity, degenerative lumbar scoliosis, sagittal imbalance, sagittal decompensation, risk factor

Sinus pericranii in children: report of 16 patients and preoperative evaluation of surgical risk

J Neurosurg Pediatrics 4:050360–500420, 2009.(DOI: 10.3171/2009.7.PEDS0994)

Sinus pericranii (SP) is a rare venous varix in an extracranial location connected to the intracranial venous system. The aim of this retrospective study was to report on 16 pediatric cases of SP with consideration of the preoperative evaluation of surgical risk.

Methods. The study population consisted of 10 patients who had undergone surgery for SP and 6 patients with concomitant craniosynostosis and SP. The mean age of the patients at presentation was 3.7 years. To identify characteristics of SP with high operative risk, 8 cases in this report and 11 previously reported cases of SP with sufficient information were categorized on the basis of the number and size of SP, the number and size of transcranial channels, the venous drainage type, and the amount of blood loss. Hemorrhage amounts were classified into 3 grades based on the description of intraoperative blood loss.

Results. Sinus pericranii not associated with craniosynostosis were resected without any postoperative morbidity. Sinus pericranii associated with craniosynostosis were preserved. After craniofacial reconstruction, 2 cases of SP with craniosynostosis regressed, completely in one patient and partially in another. These 2 patients with SP were confirmed to have compromised intracranial sinus before craniofacial reconstruction. Among a total of 19 patients, multiplicity or size (> 6 cm) of SP (p = 0.036) and multiplicity (> 3) or size (> 3 mm) of transcranial channels (p = 0.004) was associated with more severe hemorrhage grade. Sinus pericranii with peripheral venous drainage (drainer type) was not associated with hemorrhage grade after classification into 3 grades (p = 0.192). However, all 3 cases of SP with massive Grade 3 hemorrhage were the drainer type. Hemorrhage grade was correlated with the number of risk factors for SP (r = 0.793, p < 0.001).

Conclusions. Three risk factors of SP and the presence of compromised intracranial sinus are markers for high-risk SP. “Squeezed-out sinus syndrome” is suggested as a concept for SP associated with compromised intracranial sinus, mainly caused by craniosynostosis. Sinus pericranii in squeezed-out sinus syndrome probably serves as a crucial alternative to venous drainage of the brain with intracranial venous compromise. Conservative treatment for such patients with SP is recommended.

Risk factors for adjacent segment disease after lumbar fusion

Eur Spine J (2009) 18:1637–1643 DOI 10.1007/s00586-009-1060-3

The incidence of adjacent segment problems after lumbar fusion has been found to vary, and risk factors for these problems have not been precisely verified, espe- cially based on structural changes determined by magnetic resonance imaging.

The purpose of this retrospective clinical study was to describe the incidence and clinical features of adjacent segment disease (ASD) after lumbar fusion and to determine its risk factors.

We assessed the incidence of ASD in patients who underwent lumbar or lumbosacral fusions for degenerative conditions between August 1995 and March 2006 with at least a 1-year follow- up. Patients less than 35 years of age at the index spinal fusion, patients with uninstrumented fusion, and patients who had not achieved successful union were excluded.

Of the 1069 patients who underwent fusions, 28 (2.62%) needed secondary operations because of ASD and were included in this study. In order to identify the risk factors, we matched a disease group and a control group. The disease group consisted of 26 of the 28 patients with ASD, excluding the 2 patients for whom we did not have initial MRI data. Each patient in the disease group was matched by age, sex, fusion level and follow-up period with a control patient. The assumed risk factors included disc and facet degeneration, instability, listhesis, rotational defor- mity, and disc wedging. The mean age of the 28 patients with ASD requiring surgical treatment was 58.4 years, which did not differ significantly from that of the population in which ASD did not develop (58.2years, p = 0.894). Of the 21 patients who underwent floating fusion, only 1 developed distal ASD. Facet degeneration was a significant risk factor (p<0.01) on logistic regression analysis. The incidence of distal ASD was much lower than that of proximal ASD. Pre-existing facet degeneration may be associated with a high risk of adjacent segment problems following lumbar fusion procedures.

Cross-sectional magnetic resonance imaging study of lumbar disc degeneration in 200 healthy individuals

J Neurosurg Spine 11:501–507, 2009. (DOI: 10.3171/2009.5.SPINE08675)

Object. The current cross-sectional observational MR imaging study aimed to investigate the prevalence and risk factors of lumbar disc degeneration in a healthy population and to establish the baseline data for a prospective longitudinal study.

Methods. Two hundred healthy volunteers participated in this study after providing informed consent. The status of lumbar disc degeneration was assessed by 3 independent observers, who used sagittal T2-weighted MR imaging. Demographic data collected included age, sex, body mass index, episode(s) of low-back pain, smoking status, hours of standing and sitting, and Roland-Morris Disability Questionnaire scores. There were 68 men and 132 women whose mean age was 39.7 years (range 30–55 years). Eighty-two individuals (41%) were smokers, and the Roland- Morris Disability Questionnaire scores were averaged to 0.6/24.

Results. The prevalence of disc degeneration was 7.0% in L1–2, 12.0% in L2–3, 15.5% in L3–4, 49.5% in L4–5, and 53.0% in L5–S1. A herniated disc was observed at the corresponding levels in 0.5, 3.5, 6.5, 25.0, and 35.0% of cases respectively. Spondylolisthesis was observed in < 3% of this population. Multiple logistic regression analysis demonstrated that age and hours sitting were significantly related to L4–5 disc herniation. Episode of low-back pain, smoking status, body mass index, and hours standing did not affect the prevalence of disc degeneration.

Conclusions. The current study established the baseline data of lumbar disc degeneration in a 30- to 55-year-old healthy population for a prospective longitudinal study. Hours spent sitting significantly increased the prevalence of disc herniation, but episode of low-back pain, smoking status, obesity, and standing hours were not significant risk factors.

Risk factors for postoperative systemic complications in elderly patients with brain tumors

In elderly patients with brain tumors, the prevention of postoperative systemic complications is extremely important, and identification of the risk factors would be useful for planning therapy. The authors investigated ways to avoid postoperative complications by identifying risk factors.

The study population included 84 patients, 70 years of age or older, who underwent surgical brain tumor removal. The following independent factors were assessed by univariate and multivariate analyses: sex, age, preoperative underlying diseases and complications, histopathological findings, preoperative Karnofsky Performance Scale (KPS) score, preoperative whole blood hemoglobin (Hb) level, preoperative serum total protein (TP) level, operation time, intraoperative blood loss, change in Hb level (difference between pre- and postoperative values), and change in TP level (difference between pre- and postoperative values). The cutoff values for significant independent factors were also determined.

Overall, 35 (41.7%) of the 84 patients had a total of 56 postoperative systemic complications. Univariate analysis identified the preoperative KPS score, intraoperative blood loss, change in Hb level, and change in TP level as risk factors for postoperative complications, and multivariate analysis extracted the following risk factors: the preoperative KPS score (p = 0.0450, OR 4.020), intraoperative blood loss (p = 0.0104, OR 6.571), and change in Hb levels (p = 0.0023, OR 9.301). The cutoff values were: KPS score < 80%, intraoperative blood loss ≥ 350 ml, and change in Hb level ≥ 2.0 g/dl.

In elderly patients with brain tumors, low preoperative KPS score, high intraoperative blood loss, and a large difference between pre- and postoperative Hb levels are significant risk factors for postoperative systemic complications.