The demographic, clinical, and management differences between traumatic dens fracture patients with and without simultaneous atlas fractures.

Introduction: Atlas fractures often accompany traumatic dens fractures, but existing literature on the management of simultaneous atlantoaxial fractures is limited. Methods: We examined all patients with traumatic dens fractures at our institution between 2008 and 2018. We used multivariable logistic regression and ordinal logistic regression to identify factors independently associated with presentation with a simultaneous atlas fracture, as well myelopathy severity, fracture nonunion, and selection for surgery. Results: Two hundred and eighty-two patients with traumatic dens fractures without subaxial fractures were identified, including 65 (22.8%) with simultaneous atlas fractures. The distribution of injury mechanisms differed between groups (χ2 P = 0.0360). On multivariable logistic regression, dens nonunion was positively associated with type II fractures (odds ratio [OR] = 2.00, P = 0.038) and negatively associated with having surgery (OR = 0.52, P = 0.049), but not with having a C1 fracture (P = 0.3673). Worse myelopathy severity on presentation was associated with having a severe injury severity score (OR = 102.3, P < 0.001) and older age (OR = 1.28, P = 0.002), but not with having an atlas fracture (P = 0.2446). Having a simultaneous atlas fracture was associated with older age (OR = 1.29, P = 0.024) and dens fracture angulation (OR = 2.62, P = 0.004). Among patients who underwent surgery, C1/C2 posterior fusion was the most common procedure, and having a simultaneous atlas fracture was associated with selection for occipitocervical fusion (OCF) (OR = 14.35, P = 0.010). Conclusions: Among patients with traumatic dens, patients who have simultaneous atlas fractures are a distinct subpopulation with respect to age, mechanism of injury, fracture morphology, and management. Traumatic dens fractures with simultaneous atlas fractures are independently associated with selection for OCF rather than posterior cervical fusion alone.

Segmental infralesional pathological spontaneous activity in subacute traumatic spinal cord injury.

INTRODUCTION/AIMS: There is a dearth of knowledge regarding the status of infralesional lower motor neurons (LMNs) in individuals with traumatic cervical spinal cord injury (SCI), yet there is a growing need to understand how the spinal lesion impacts LMNs caudal to the lesion epicenter, especially in the context of nerve transfer surgery to restore several key upper limb functions. Our objective was to determine the frequency of pathological spontaneous activity (PSA) at, and below, the level of spinal injury, to gain an understanding of LMN health below the spinal lesion. METHODS: Ninety-one limbs in 57 individuals (53 males, mean age = 44.4 ± 16.9 years, mean duration from injury = 3.4 ± 1.4 months, 32 with motor complete injuries), were analyzed. Analysis was stratified by injury level as (1) C4 and above, (2) C5, and (3) C6-7. Needle electromyography was performed on representative muscles innervated by the C5-6, C6-7, C7-8, and C8-T1 nerve roots. PSA was dichotomized as present or absent. Data were pooled for the most caudal infralesional segment (C8-T1). RESULTS: A high frequency of PSA was seen in all infralesional segments. The pooled frequency of PSA for all injury levels at C8-T1 was 68.7% of the limbs tested. There was also evidence of PSA at the rostral border of the neurological level of injury, with 58.3% of C5-6 muscles in those with C5-level injuries. DISCUSSION: These data support a high prevalence of infralesional LMN abnormalities following SCI, which has implications to nerve transfer candidacy, timing of the intervention, and donor nerve options.

Traumatic Dens Fracture Patients Comprise Distinct Subpopulations Distinguished by Differences in Age, Sex, Injury Mechanism and Severity, and Outcome.

BACKGROUND: Dens fractures are an increasingly common injury, yet their epidemiology and its implications remain underexamined. METHODS: We retrospectively analyzed all traumatic dens fracture patients managed at our institution over a 10-year period, examining demographic, clinical, and outcomes data. Patient subsets were compared across these parameters. RESULTS: Among 303 traumatic dens fracture patients, we observed a bimodal age distribution with a strong goodness of fit centered at age 22.3 ± 5.7 (R = 0.8781) and at 77.7 ± 13.9 (R = 0.9686). A population pyramid demonstrated a bimodal distribution among male patients, but not female patients, which was confirmed with a strong goodness of fit for male patient subpopulations age <35 (R = 0.9791) and age ≥35 (R = 0.8843), but a weaker fit for a second female subpopulation age <35. Both age groups were equally likely to undergo surgery. Patients younger than age 35 were more likely to be male (82.4% vs. 46.9%, odds ratio [OR] = 5.29 [1.54, 17.57], P = 0.0052), have motor vehicle collision as their mechanism of injury (64.7% vs. 14.1%, OR = 11.18 [3.77, 31.77], P < 0.0001), and to have a severe trauma injury severity score (17.6% vs. 2.9%, OR = 7.23 [1.88, 28.88], P = 0.0198). Nevertheless, patients age <35 were less likely to have fracture nonunion at follow (18.2% vs. 53.7%, OR = 0.19 [0.041, 0.76], P = 0.0288). CONCLUSIONS: The dens fracture patient population comprises 2 subpopulations, distinguished by differences in age, sex, injury mechanism and severity, and outcome, with male dens fracture patients demonstrating a bimodal age distribution. Young, male patients were more likely to have high-energy injury mechanisms leading to severe trauma, yet were less likely to have fracture nonunion at follow-up.

Odontoid fracture type and angulation affect nonunion risk, but comminution and displacement do not: A propensity score matched analysis of fracture morphology.

OBJECTIVE: Odontoid fractures disproportionately affect older patients who have high surgical risk, but also high rates of fracture nonunion. To guide surgical decision-making, we quantified the effect of fracture morphology on nonunion among nonoperatively managed, traumatic, isolated odontoid fractures. METHODS: We examined all patients with isolated odontoid fractures treated nonoperatively at our institution between 2010 and 2019. Multivariable regression and propensity score matching were used to quantify the effect of fracture type, angulation, comminution, and displacement on bony healing by 26 weeks from injury. RESULTS: 303 consecutive traumatic odontoid fracture patients were identified, of whom 163 (53.8 %) had isolated fractures that were managed nonoperatively. Selection for nonoperative management was more likely with older age (OR=1.31 [1.09, 1.58], p = 0.004), and less likely with higher fracture angle (OR=0.70 [0.55, 0.89], p = 0.004), or higher presenting Nurick scores (OR=0.77 [0.62, 0.94], p = 0.011). Factors associated with nonunion at 26 weeks were fracture angle (OR=5.11 [1.43, 18.26], p = 0.012) and Anderson-D'Alonzo Type II morphology (OR=5.79 [1.88, 17.83], p = 0.002). Propensity score matching to assess the effect of type II fracture, fracture angulation> 10o, displacement≥ 3 mm, and comminution all yielded balanced models (Rubin's B<25.0, 0.5  10o (p = 0.015), and there was an 18.2 % lower rate of bony healing for each 10o increase in fracture angle. Fracture displacement≥ 3 mm and comminution had no significant effect. CONCLUSION: Type II fracture morphology and fracture angle > 10o significantly increase nonunion among nonoperatively managed isolated traumatic odontoid fractures, but fracture comminution and displacement ≥ 3 mm do not.

Surgery Decreases Nonunion, Myelopathy, and Mortality for Patients With Traumatic Odontoid Fractures: A Propensity Score Matched Analysis.

BACKGROUND: Existing literature suggests that surgical intervention for odontoid fractures is beneficial but often does not control for known confounding factors. OBJECTIVE: To examine the effect of surgical fixation on myelopathy, fracture nonunion, and mortality after traumatic odontoid fractures. METHODS: We analyzed all traumatic odontoid fractures managed at our institution between 2010 and 2020. Ordinal multivariable logistic regression was used to identify factors associated with myelopathy severity at follow-up. Propensity score analysis was used to test the treatment effect of surgery on nonunion and mortality. RESULTS: Three hundred and three patients with traumatic odontoid fracture were identified, of whom 21.6% underwent surgical stabilization. After propensity score matching, populations were well balanced across all analyses (Rubin's B < 25.0, 0.5 < Rubin's R < 2.0). Controlling for age and fracture angulation, type, comminution, and displacement, the overall rate of nonunion was lower in the surgical group (39.7% vs 57.3%, average treatment effect [ATE] = -0.153 [-0.279, -0.028], P = .017). Controlling for age, sex, Nurick score, Charlson Comorbidity Index, Injury Severity Score, and selection for intensive care unit admission, the mortality rate was lower for the surgical group at 30 days (1.7% vs 13.8%, ATE = -0.101 [-0.172, -0.030], P = .005) and at 1 year was 7.0% vs 23.7%, ATE = -0.099 [-0.181, -0.017], P = .018. Cox proportional hazards analysis also demonstrated a mortality benefit for surgery (hazard ratio = 0.587 [0.426, 0.799], P = .0009). Patients who underwent surgery were less likely to have worse myelopathy scores at follow-up (odds ratio = 0.48 [0.25, 0.93], P = .029). CONCLUSION: Surgical stabilization is associated with better myelopathy scores at follow-up and causes lower rates of fracture nonunion, 30-day mortality, and 1-year mortality.

Outcomes following anterior odontoid screw versus posterior arthrodesis for odontoid fractures: a systematic review and meta-analysis.

OBJECTIVE: Odontoid fractures can be managed surgically when indicated. The most common approaches are anterior dens screw (ADS) fixation and posterior C1-C2 arthrodesis (PA). Each approach has theoretical advantages, but the optimal surgical approach remains controversial. The goal in this study was to systematically review the literature and synthesize outcomes including fusion rates, technical failures, reoperation, and 30-day mortality associated with ADS versus PA for odontoid fractures. METHODS: A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by searching the PubMed, EMBASE, and Cochrane databases. A random-effects meta-analysis was performed and the I2 statistic was used to assess heterogeneity. RESULTS: In total, 22 studies comprising 963 patients (ADS 527, PA 436) were included. The average age of the patients ranged from 28 to 81.2 years across the included studies. The majority of the odontoid fractures were type II based on the Anderson-D'Alonzo classification. The ADS group was associated with statistically significantly lower odds to achieve bony fusion at last follow-up compared to the PA group (ADS 84.1%; PA 92.3%; OR 0.46; 95% CI 0.23-0.91; I2 42.6%). The ADS group was associated with statistically significantly higher odds of reoperation compared to the PA group (ADS 12.4%; PA 5.2%; OR 2.56; 95% CI 1.50-4.35; I2 0%). The rates of technical failure (ADS 2.3%; PA 1.1%; OR 1.11; 95% CI 0.52-2.37; I2 0%) and all-cause mortality (ADS 6%; PA 4.8%; OR 1.35; 95% CI 0.67-2.74; I2 0%) were similar between the two groups. In the subgroup analysis of patients > 60 years old, the ADS was associated with statistically significantly lower odds of fusion compared to the PA group (ADS 72.4%; PA 89.9%; OR 0.24; 95% CI 0.06-0.91; I2 58.7%). CONCLUSIONS: ADS fixation is associated with statistically significantly lower odds of fusion at last follow-up and higher odds of reoperation compared to PA. No differences were identified in the rates of technical failure and all-cause mortality. Patients receiving ADS fixation at > 60 years old had significantly higher and lower odds of reoperation and fusion, respectively, compared to the PA group. PA is preferred to ADS fixation for odontoid fractures, with a stronger effect size for patients > 60 years old.

Outpatient telemedicine in neurosurgery: 15,677 consecutive encounters in a comparative analysis of its effectiveness and impact on the surgical conversion rate.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has necessitated the use of telehealth visits (THVs). The effects on neurosurgical practice have not been well characterized, especially concerning new-patient THVs. Therefore, the authors of this study reviewed their institution's experience with outpatient clinic visits and THVs from before the COVID-19 pandemic to the present to focus on clinical metrics, rates of surgery, and the effects of implementing THVs in order to better understand their implications for clinical practice as more data emerge over time. METHODS: The authors reviewed 15,677 consecutive new outpatient in-person visits (IPVs), THVs, and neurosurgical procedures/cases proceeding from their institution between 2018 and 2022 for trends and associations related to THVs. RESULTS: Among spine patients, there was no difference in the proportion of encounters that led to surgery (surgical conversion rate) between THVs and IPVs (p = 0.49). Among cranial patients, THVs were negatively associated with conversion (OR 0.73, p = 0.03). On average, patients using THVs lived further from the hospital (p < 0.001); however, the patient catchment area appeared unchanged. The median distance to the hospital among THV patients was counterbalanced by a decreased distance for spine patients pursing IPVs (p < 0.001), with no significant change to case volume. There was no change in distance to the hospital among cranial patients. For both cranial and spine patients, surgical conversion was more likely among those who lived a great distance from the hospital if their initial encounter was an IPV (p = 0.007 and < 0.001, respectively). However, there was no relationship between distance from the hospital and surgical conversion among THV patients (p = 0.565). The availability of THVs did not significantly affect follow-up time (p = 0.837). For new patients at IPVs, there was no difference in time to the operating room between cranial and spine cases; for new patients at THVs, however, time to the operating room was significantly faster for cranial cases than for spine cases (p = 0.0018). CONCLUSIONS: Compared to IPVs, THVs lead to decreased surgical conversion for cranial patients but not spine patients. THVs do not appear to increase the catchment area. For patients who live far from the hospital, an IPV is associated with surgical conversion. Surgical conversion is faster following cranial THVs than after spine THVs. THVs did not increase the duration of follow-up.

Anterior approach lumbar fusions cause a marked increase in thromboembolic events: Causal inferences from a propensity-matched analysis of 1147 patients.

OBJECTIVE: Anterior lumbar fusions are thought to be associated with elevated venous thromboembolic event (VTE) rates, but the magnitude of this increase in VTE is not well described. The objective of this study was to quantify any increase in VTE caused by anterior approach lumbar fusion. METHODS: 1147 consecutive lumbar fusions performed at our institution over a six-year period were identified, and clinical and demographic data were collected. K-nearest neighbor propensity score matching and propensity score adjusted regression were performed. Patients undergoing anterior versus posterior approach lumbar fusions were matched according to age, body mass index, sex, VTE history, estimated blood loss, length of surgery, transfusion, selection for postoperative intensive care unit (ICU) admission, comorbid disease burden, and use of chemoprophylactic anticoagulation. RESULTS: Anterior approach surgery (OR=4.29, p < 0.001), a history of VTE (OR=8.67, p < 0.001), age (OR=1.53, p = 0.014), length of surgery (OR=1.16, p = 0.044), and selection for postoperative ICU admission (OR=4.60, p = 0.005) were independently associated with VTE on multivariable regression. 1058 anterior or posterior approach fusion patients were matched. After matching, overall bias was reduced by 71.0 %, no covariates remained significantly different between groups, and propensity scores were well balanced between populations (Rubin's B≤0.25, 0.5 ≤Rubin's R≤2.0). Significantly more patients in the anterior group underwent lower extremity duplex ultrasonography (LED) (36.9 % vs. 14.8 %, OR=3.36 [2.38, 4.76], p < 0.0001), and a statistically insignificantly higher proportion of LEDs were positive among patients in the anterior group (23.2 % vs. 13.2 %, OR=1.99 [0.92, 4.25], p = 0.108). After matching, the rate of VTE was 8.6 % for the anterior group and 1.3 % for the posterior group, with anterior approach surgery causing an increase in VTE by 7.2 % (95 % CI [2.28 %, 12.16 %], p = 0.004). CONCLUSION: Among patients undergoing lumbar fusions, anterior approach surgery causes an increase in VTE by 7.2%, which is a multifold increase in the proportion of patients with thromboembolic complications.

The distribution of acquired peripheral nerve injuries associated with severe COVID-19 implicate a mechanism of entrapment neuropathy: a multicenter case series and clinical feasibility study of a wearable, wireless pressure sensor.

We diagnosed 66 peripheral nerve injuries in 34 patients who survived severe coronavirus disease 2019 (COVID-19). We combine this new data with published case series re-analyzed here (117 nerve injuries; 58 patients) to provide a comprehensive accounting of lesion sites. The most common are ulnar (25.1%), common fibular (15.8%), sciatic (13.1%), median (9.8%), brachial plexus (8.7%) and radial (8.2%) nerves at sites known to be vulnerable to mechanical loading. Protection of peripheral nerves should be prioritized in the care of COVID-19 patients. To this end, we report proof of concept data of the feasibility for a wearable, wireless pressure sensor to provide real time monitoring in the intensive care unit setting.

Natural Language Processing in Spine Surgery: A Systematic Review of Applications, Bias, and Reporting Transparency.

BACKGROUND: Natural language processing (NLP) is a discipline of machine learning concerned with the analysis of language and text. Although NLP has been applied to various forms of clinical text, the applications and utility of NLP in spine surgery remain poorly characterized. Here, we systematically reviewed studies that use NLP for spine surgery applications, and analyzed applications, bias, and reporting transparency of the studies. METHODS: We performed a literature search using the PubMed, Scopus, and Embase databases. Data extraction was performed after appropriate screening. The risk of bias and reporting quality were assessed using the PROBAST and TRIPOD tools. RESULTS: A total of 12 full-text articles were included. The most common diseases represented include spondylolisthesis (25%), scoliosis (17%), and lumbar disk herniation (17%). The most common procedures included spinal fusion (42%), imaging (e.g. magnetic resonance, X-ray) (25%), and scoliosis correction (17%). Reported outcomes were diverse and included incidental durotomy, venous thromboembolism, and the tone of social media posts regarding scoliosis surgery. Common sources of bias identified included the use of older methods that do not capture the nuance of a text, and not using a prespecified or standard outcome measure when evaluating NLP methods. CONCLUSIONS: Although the application of NLP to spine surgery is expanding, current studies face limitations and none are indicated as ready for clinical use. Thus, for future studies we recommend an emphasis on transparent reporting and collaboration with NLP experts to incorporate the latest developments to improve models and contribute to further innovation.

Anterior interosseous nerve neuropathy in a patient with spinal cord injury: case report and literature review.

INTRODUCTION: Entrapment neuropathies, typically carpal tunnel syndrome and ulnar neuropathy, frequently occur in patients with spinal cord injury (SCI). Upper limb impairments due to entrapment neuropathy can be particularly debilitating in this population. Anterior interosseous nerve (AIN) neuropathy has not been previously described in the SCI population. CASE PRESENTATION: A 27-year-old left-handed man with a history of C7 ASIA Impairment Scale B spinal cord injury five years prior presented to clinic with decreased left thumb function as well as thumb flexion. Workup including nerve conduction studies, electromyogram, ultrasonographic assessment, and magnetic resonance neurography was consistent with compressive AIN neuropathy. Surgical exploration and neurolysis was performed, with improvement of symptoms. DISCUSSION: Entrapment neuropathies should be carefully considered in the evaluation of patients with SCI with new motor deficits. We report a case of AIN neuropathy in a patient with SCI successfully treated with surgical decompression, and review the literature describing upper extremity entrapment neuropathies in this population. Surgical decompression is an effective option for treatment of AIN neuropathy in the setting of SCI, though further characterization of the optimal management strategy is needed.

Outcomes and complications of minimally invasive transforaminal lumbar interbody fusion in the elderly: a systematic review and meta-analysis.

OBJECTIVE: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) may be used to treat degenerative spinal pathologies while reducing risks associated with open procedures. As an increasing number of lumbar fusions are performed in the aging United States population, MIS-TLIF has been widely adopted into clinical practice in recent years. However, its complication rate and functional outcomes in elderly patients remain poorly characterized. The objective of this study was to assess complication rates and functional outcomes in elderly patients (≥ 65 years old) undergoing MIS-TLIF. METHODS: The PubMed, Embase, and Scopus databases were searched for relevant records in accordance with the PRISMA guidelines. Inclusion criteria were peer-reviewed original research; English language; full text available; use of MIS-TLIF; and an elderly cohort of at least 5 patients. Risk of bias was assessed using the ROBINS-I (Risk of Bias in Nonrandomized Studies-of Interventions) tool. Pooled complication rates were calculated for elderly patients, with subgroup analyses performed for single versus multiple-level fusions. Complication rates in elderly compared to nonelderly patients were also assessed. Postoperative changes in patient-reported outcomes, including Oswestry Disability Index (ODI) and visual analog scale (VAS) back pain (BP) and leg pain (LP) scores, were calculated. RESULTS: Twelve studies were included in the final analysis. Compared to nonelderly patients, MIS-TLIF in elderly patients resulted in significantly higher rates of major (OR 2.15, 95% CI 1.07-4.34) and minor (OR 2.20, 95% CI 1.22-3.95) complications. The pooled major complication rate in elderly patients was 0.05 (95% CI 0.03-0.08) and the pooled minor complication rate was 0.20 (95% CI 0.13-0.30). Single-level MIS-TLIF had lower major and minor complication rates than multilevel MIS-TLIF, although not reaching significance. At a minimum follow-up of 6 months, the postoperative change in ODI (-30.70, 95% CI -41.84 to -19.55), VAS-BP (-3.87, 95% CI -4.97 to -2.77), and VAS-LP (-5.11, 95% CI -6.69 to -3.53) in elderly patients all exceeded the respective minimum clinically important difference. The pooled rate of fusion was 0.86 (95% CI 0.80-0.90). CONCLUSIONS: MIS-TLIF in elderly patients results in a high rate of fusion and significant improvement of patient-reported outcomes, but has significantly higher complication rates than in nonelderly patients. Limitations of this study include heterogeneity in the definition of elderly and limited reporting of risk factors among included studies. Further study of the impact of complications and the factors predisposing elderly patients to poor outcomes is needed.

Spinal arthrodesis via lumbar interbody fusion without direct decompression as a treatment for recurrent radicular pain due to epidural fibrosis: patient series.

BACKGROUND: Lumbar radiculopathy is the most common indication for lumbar discectomy, but residual postoperative radicular symptoms are common. Postoperative lumbar radiculopathy secondary to scar formation is notoriously difficult to manage, with the mainstay of treatment focused on nonoperative techniques. Surgical intervention for epidural fibrosis has shown unacceptably high complication rates and poor success rates. OBSERVATIONS: Three patients underwent spinal arthrodesis without direct decompression for recurrent radiculopathy due to epidural fibrosis. Each patient previously underwent lumbar discectomy but subsequently developed recurrent radiculopathy. Imaging revealed no recurrent disc herniation, although it demonstrated extensive epidural fibrosis and scar in the region of the nerve root at the previous surgical site. Dynamic radiographs showed no instability. Two patients underwent lateral lumbar interbody fusion, and one patient underwent anterior lumbosacral interbody fusion. Each patient experienced resolution of radicular symptoms by the 1-year follow-up. Average EQ visual analog scale scores improved from 65 preoperatively to 78 postoperatively. LESSONS: Spinal arthrodesis via lumbar interbody fusion, without direct decompression, may relieve pain in patients with recurrent radiculopathy due to epidural fibrosis, even in the absence of gross spinal instability.

Impact of Michigan's new opioid prescribing laws on spine surgery patients: analysis of the Michigan Spine Surgery Improvement Collaborative.

OBJECTIVE: In 2017, Michigan passed new legislation designed to reduce opioid abuse. This study evaluated the impact of these new restrictive laws on preoperative narcotic use, short-term outcomes, and readmission rates after spinal surgery. METHODS: Patient data from 1 year before and 1 year after initiation of the new opioid laws (beginning July 1, 2018) were queried from the Michigan Spine Surgery Improvement Collaborative database. Before and after implementation of the major elements of the new laws, 12,325 and 11,988 patients, respectively, were treated. RESULTS: Patients before and after passage of the opioid laws had generally similar demographic and surgical characteristics. Notably, after passage of the opioid laws, the number of patients taking daily narcotics preoperatively decreased from 3783 (48.7%) to 2698 (39.7%; p < 0.0001). Three months postoperatively, there were no differences in minimum clinically important difference (56.0% vs 58.0%, p = 0.1068), numeric rating scale (NRS) score of back pain (3.5 vs 3.4, p = 0.1156), NRS score of leg pain (2.7 vs 2.7, p = 0.3595), satisfaction (84.4% vs 84.7%, p = 0.6852), or 90-day readmission rate (5.8% vs 6.2%, p = 0.3202) between groups. Although there was no difference in readmission rates, pain as a reason for readmission was marginally more common (0.86% vs 1.22%, p = 0.0323). CONCLUSIONS: There was a meaningful decrease in preoperative narcotic use, but notably there was no apparent negative impact on postoperative recovery, patient satisfaction, or short-term outcomes after spinal surgery despite more restrictive opioid prescribing. Although the readmission rate did not significantly increase, pain as a reason for readmission was marginally more frequently observed.

Three-Dimensional Navigated Lateral Lumbar Interbody Fusion: 2-Dimensional Operative Video.

Spondylolisthesis is a common cause of lower back and leg pain in adults. The initial treatment for patients is typically nonoperative in nature. However, when patients fail conservative management and their back and/or leg pain is recalcitrant, surgical intervention is warranted. Spinal decompression, either directly or indirectly, as well as fusion is often considered at this point. There are numerous approaches to fuse the spine, including anterior, lateral, or posterior, each with their own advantages and disadvantages. This video illustrates a case of symptomatic spondylolisthesis occurring after laminectomy treated by lateral lumbar interbody fusion for indirect decompression and stabilization. The approach utilizes 3-dimensional navigation rather than traditional fluoroscopy, resulting in markedly decreased radiation exposure for the surgeon and staff while maintaining accuracy. Appropriate patient consent was obtained. This video demonstrates the technique for a lateral lumbar interbody fusion using navigation assistance, which is a minimally invasive technique for the treatment of spondylolisthesis.

The impact of age on approach-related complications with navigated lateral lumbar interbody fusion.

OBJECTIVE: Age is known to be a risk factor for increased complications due to surgery. However, elderly patients can gain significant quality-of-life benefits from surgery. Lateral lumbar interbody fusion (LLIF) is a minimally invasive procedure that is commonly used to treat degenerative spine disease. Recently, 3D navigation has been applied to LLIF. The purpose of this study was to determine whether there is an increased complication risk in the elderly with navigated LLIF. METHODS: Patients who underwent 3D-navigated LLIF for degenerative disease from 2014 to 2019 were included in the analysis. Patients were divided into elderly and nonelderly groups, with those 65 years and older categorized as elderly. Ninety-day medical and surgical complications were recorded. Patient and surgical characteristics were compared between groups, and multivariate regression analysis was used to determine independent risk factors for complication. RESULTS: Of the 115 patients included, 56 were elderly and 59 were nonelderly. There were 15 complications (25.4%) in the nonelderly group and 10 (17.9%) in the elderly group, which was not significantly different (p = 0.44). On multivariable analysis, age was not a risk factor for complication (p = 0.52). However, multiple-level LLIF was associated with an increased risk of approach-related complication (OR 3.58, p = 0.02). CONCLUSIONS: Elderly patients do not appear to experience higher rates of approach-related complications compared with nonelderly patients undergoing 3D navigated LLIF. Rather, multilevel surgery is a predictor for approach-related complication.

The feasibility of computer-assisted 3D navigation in multiple-level lateral lumbar interbody fusion in combination with posterior instrumentation for adult spinal deformity.

OBJECTIVE: The lateral lumbar interbody fusion (LLIF) technique is used to treat many common spinal degenerative pathologies including kyphoscoliosis. The use of spinal navigation for LLIF has not been broadly adopted, especially in adult spinal deformity. The purpose of this study was to evaluate the feasibility as well as the intraoperative and navigation-related complications of computer-assisted 3D navigation (CaN) during multiple-level LLIF for spinal deformity. METHODS: Retrospective analysis of clinical and operative characteristics was performed for all patients > 18 years of age who underwent multiple-level CaN LLIF combined with posterior instrumentation for adult spinal deformity at the University of Michigan between 2014 and 2020. Intraoperative CaN-related complications, LLIF approach-related postoperative complications, and medical postoperative complications were assessed. RESULTS: Fifty-nine patients were identified. The mean age was 66.3 years (range 42-83 years) and body mass index was 27.6 kg/m2 (range 18-43 kg/m2). The average coronal Cobb angle was 26.8° (range 3.6°-67.0°) and sagittal vertical axis was 6.3 cm (range -2.3 to 14.7 cm). The average number of LLIF and posterior instrumentation levels were 2.97 cages (range 2-5 cages) and 5.78 levels (range 3-14 levels), respectively. A total of 6 intraoperative complications related to the LLIF stage occurred in 5 patients. Three of these were CaN-related and occurred in 2 patients (3.4%), including 1 misplaced lateral interbody cage (0.6% of 175 total lateral cages placed) requiring intraoperative revision. No patient required a return to the operating room for a misplaced interbody cage. A total of 12 intraoperative complications related to the posterior stage occurred in 11 patients, with 5 being CaN-related and occurring in 4 patients (6.8%). Univariate and multivariate analyses revealed no statistically significant risk factors for intraoperative and CaN-related complications. Transient hip weakness and numbness were found to be in 20.3% and 22.0% of patients, respectively. At the 1-month follow-up, weakness was observed in 3.4% and numbness in 11.9% of patients. CONCLUSIONS: Use of CaN in multiple-level LLIF in the treatment of adult spinal deformity appears to be a safe and effective technique. The incidence of approach-related complications with CaN was 3.4% and cage placement accuracy was high.

Surgical management of atlantoaxial dislocation and cervical spinal cord injury in craniopagus twins.

A case of cervical spinal cord injury in 12-year-old angular craniopagus twins is presented, with a description of the planning and execution of surgical treatment along with subsequent clinical outcome. The injury occurred following a fall from a standing position, resulting in quadriparesis in one of the twins. Imaging revealed severe craniocervical stenosis resulting from a C1-2 dislocation, and T2-weighted hyperintensity of the cervical spinal cord. After custom halo fixation was obtained, a posterior approach was utilized to decompress and instrument the occiput, cervical, and upper thoracic spine with intraoperative reduction of the dislocation. Early neurological improvement was noted during the acute postoperative phase, and 27 months of follow-up demonstrated intact instrumentation with continued neurological improvement to near baseline. The complexity of managing such an injury, inclusive of the surgical, anesthetic, biomechanical, and ethical considerations, is described in detail.

Effect of Fenestrated Pedicle Screws with Cement Augmentation in Osteoporotic Patients Undergoing Spinal Fusion.

OBJECTIVE: Osteoporosis is a well-known risk factor for instrumentation failure and subsequent pseudoarthrosis after spinal fusion. In the present systematic review, we analyzed the biomechanical properties, clinical efficacy, and complications of cement augmentation via fenestrated pedicle screws in spinal fusion. METHODS: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Reports appearing in the PubMed database up to March 31, 2020 were queried using the key words "cement," "pedicle screw," and "osteoporosis." We excluded non-English language studies, studies reported before 2000, studies that had involved use of cement without fenestrated pedicle screws, nonhuman studies, technical reports, and individual case reports. RESULTS: Twenty-five studies met the inclusion criteria. Eleven studies had tested the biomechanics of cement-augmented fenestrated pedicle screws. The magnitude of improvement achieved by cement augmentation of pedicle screws increased with the degree of osteoporosis. The cement-augmented fenestrated pedicle screw was superior biomechanically to the alternative "solid-fill" technique. Fourteen studies had evaluated complications. Cement extravasation with fenestrated screw usage was highly variable, ranging from 0% to 79.7%. However, cement extravasation was largely asymptomatic. Thirteen studies had assessed the outcomes. The use of cement-augmented fenestrated pedicles decreased screw pull out and improved fusion rates; however, the clinical outcomes were similar to those with traditional pedicle screw placement. CONCLUSIONS: The use of cement-augmented fenestrated pedicle screws can be an effective strategy for achieving improved pedicle screw fixation in patients with osteoporosis. A potential risk is cement extravasation; however, this complication will typically be asymptomatic. Larger comparative studies are needed to better delineate the clinical efficacy.

Patients with a depressive and/or anxiety disorder can achieve optimum Long term outcomes after surgery for grade 1 spondylolisthesis: Analysis from the quality outcomes database (QOD).

INTRODUCTION: In the current study, we sought to compare baseline demographic, clinical, and operative characteristics, as well as baseline and follow-up patient reported outcomes (PROs) of patients with any depressive and/or anxiety disorder undergoing surgery for low-grade spondylolisthesis using a national spine registry. PATIENTS AND METHODS: The Quality Outcomes Database (QOD) was queried for patients undergoing surgery for Meyerding grade 1 lumbar spondylolisthesis undergoing 1-2 level decompression or 1 level fusion at 12 sites with the highest number of patients enrolled in QOD with 2-year follow-up data. RESULTS: Of the 608 patients identified, 25.6 % (n = 156) had any depressive and/or anxiety disorder. Patients with a depressive/anxiety disorder were less likely to be discharged home (p < 0.001). At 3=months, patients with a depressive/anxiety disorder had higher back pain (p < 0.001), lower quality of life (p < 0.001) and higher disability (p = 0.013); at 2 year patients with depression and/or anxiety had lower quality of life compared to those without (p < 0.001). On multivariable regression, depression was associated with significantly lower odds of achieving 20 % or less ODI (OR 0.44, 95 % CI 0.21-0.94,p = 0.03). Presence of an anxiety disorder was not associated with decreased odds of achieving that milestone at 3 months. The presence of depressive-disorder, anxiety-disorder or both did not have an impact on ODI at 2 years. Finally, patient satisfaction at 2-years did not differ between the two groups (79.8 % vs 82.7 %,p = 0.503). CONCLUSION: We found that presence of a depressive-disorder may impact short-term outcomes among patients undergoing surgery for low grade spondylolisthesis but longer term outcomes are not affected by either a depressive or anxiety disorder.