The 5-factor modified frailty index (mFI-5) predicts adverse outcomes after elective anterior cervical discectomy and fusion (ACDF).

Background: Anterior cervical discectomy and fusion (ACDF) is a reliable procedure commonly performed in older patients with degenerative diseases of the cervical spine. Over 130,000 procedures are performed every year with an annual increase of 5%, and overall morbidity rates can reach as high as 19.3%, indicating a need for surgeons to gauge their patients' risk for adverse outcomes. Frailty is an age-associated decline in functioning of multiple organ systems and has been shown to predict adverse outcomes following various spine procedures. There have been several proposed frailty indices of various factors including the 11-factor modified frailty index (mFI-11), which has been shown to be an effective tool for predicting complications in patients undergoing ACDF. However, there is a paucity of literature assessing the utility of the 5-factor modified frailty index (mFI-5) as a risk stratification tool for patients undergoing ACDF. The purpose of this study was to analyze the predictive capability of the mFI-5 score for 30-day postoperative adverse events following elective ACDF. Methods: A retrospective review was performed using the National Surgical Quality Improvement Program (NSQIP) database from 2010 through 2019. Patients older than 50 years of age who underwent elective ACDF were identified using Current Procedural Terminology ([CPT] codes 22554, 22551, 22552, and 63075). Exclusion criteria removed patients under the age of 51, as well as those with fractures, sepsis, disseminated cancer, a prior operation in the last 30 days, ascites, wound infection, or an emergency surgery. Patients were grouped using mFI scores of 1, 2, and 3+. Univariate analysis, using chi-squared and one-way analysis of variance (ANOVA) tests, was conducted to compare demographics, comorbidities, and postoperative complications across the varying cohorts based on mFI-5 scores. Multivariate logistic regression, including patient demographics and preoperative comorbidities as covariates, was performed to evaluate if mFI-5 scores were independent predictors of 30-day postoperative adverse events. Covariates including race, BMI, sex, ASA, and comorbidities were included in regression models. Results: The 45,991 patients were identified and allocated in cohorts based on mFI-5 score. Rates for superficial surgical site infection (SSI), organ/deep space SSI, pneumonia, progressive renal insufficiency, acute renal failure (ARF), urinary tract infection (UTI), stroke/cardiovascular accident (CVA), cardiac arrest requiring cardiopulmonary resuscitation (CPR), myocardial infarction, bleeding requiring transfusions, deep vein thrombosis/thrombophlebitis, sepsis, septic shock, readmissions, reoperation, and mortality incrementally increased with mFI-5 scores from 0 to 3+. Multivariate regression analysis revealed that mFI-5 scores 1 to 3+ increased the odds, in a stepwise manner, of total complications, cardiac arrest requiring CPR, pneumonia and mortality. MFI-5 scores of 2 and 3+ were independent predictors of readmission (2: OR=1.5, p<.001; 3+: OR=2.0, p<.001) and myocardial infarction (2: OR=3.4, p=.001; 3+: OR=6.9, p<.001). A score of 3+ increased the odds of ARF (OR=9.7, p=.022), septic shock (OR=3.6, p=.036), UTI (OR=2.1, p=.007), bleeding requiring transfusions (OR=2.1, p=.016), and reoperations (OR=1.7, p=.004). Conclusion: mFI-5 score is a quick and viable option for surgeons to use as an assessment tool to stratify high risk patients undergoing elective ACDF, as increasing mFI-5 scores showed significantly higher rates of all adverse outcomes accounted for in this study, except for deep incisional SSI, wound disruption, and PE. Additionally, moderate to severe mFI-5 scores of 2 or 3+ were independent predictors for 30-day postoperative ARF, UTI, MI, bleeding requiring transfusions, septic shock, reoperation, and readmissions following elective ACDF surgery in adults over 50 years old.

Safety and Efficacy of Outpatient Anterior Cervical Disk Replacement (ACDR) in an Ambulatory Surgery Center Versus Hospital Setting: A 2-year Retrospective Analysis.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: To compare clinical outcomes of outpatient anterior cervical disk replacements (ACDR) performed in free-standing private ambulatory surgery centers versus tertiary hospital centers. SUMMARY OF BACKGROUND DATA: ACDR is an increasingly popular technique for treating various degenerative pathologies of the cervical spine. There has been an increase in the utilization of ambulatory surgery centers (ASCs) for outpatient cervical procedures due to economic and convenience benefits; however, a paucity of literature exists in evaluating long-term safety and efficacy of ACDRs performed in ASCs versus outpatient hospital centers. METHODS: A retrospective cohort review of all patients undergoing 1- or 2-level ACDRs at 2 outpatient ASCs and 4 tertiary care medical centers from 2012 to 2020, with a minimum follow-up of 24 months, was performed. Approval by each patient's insurance and patient preference determined distribution into an ASC or non-ASC. Demographics, perioperative data, length of follow-up, complications, and revision rates were analyzed. Functional outcomes were assessed using VAS and NDI at follow-up visits. RESULTS: One hundred seventeen patients were included (65 non-ASC and 52 ASC). There were no significant differences in demographics or length of follow-up between the cohorts. ASC patients had significantly lower operative times (ASC: 89.5 minutes vs. non-ASC: 110.5 minutes, P<0.001) and mean blood loss (ASC: 17.5 mL vs. non-ASC: 25.3 mL, P<0.001). No significant differences were observed in rates of dysphagia (ASC: 21.2% vs. non-ASC: 15.6%, P<0.001), infection (ASC: 0.0% vs. non-ASC: 1.6%, P=0.202), ASD (ASC: 1.9% vs. non-ASC: 1.6%, P=0.202), or revision (ASC: 1.9% vs. non-ASC: 0.0%, P=0.262). Both groups demonstrated significant improvements in VAS and NDI scores (P<0.001), but no significant differences in the degree of improvement were observed. CONCLUSIONS: Our 2-year results demonstrate that ACDRs performed in ASCs may offer the advantages of reduced operative time and blood loss without an increased risk of postoperative complications.

Comparing outcomes between anterior cervical disc replacement (ACDR) and minimally invasive posterior cervical foraminotomy (MI-PCF) in the treatment of cervical radiculopathy.

BACKGROUND CONTEXT: Anterior cervical disc replacement (ACDR) and minimally invasive posterior cervical foraminotomy (MI-PCF) have emerged as two increasingly popular alternatives to anterior cervical discectomy and fusion (ACDF) for the management of cervical radiculopathy. Both techniques provide advantages of segmental motion preservation and lower rates of adjacent segment degeneration (ASD) compared to ACDF. PURPOSE: The purpose of this study was to analyze the clinical and functional outcomes of patients undergoing ACDR or MI-PCF for the treatment of unilateral cervical radiculopathy. STUDY DESIGN/SETTING: Retrospective Cohort Review. PATIENT SAMPLE: A total of 152 patients were included (86 ACDR and 66 MI-PCF). OUTCOME MEASURES: (1) Patient demographics; (2) perioperative data; (3) rates of complications and revisions; (5) visual analogue scale (VAS) and Neck Disability Index (NDI) scores. METHODS: A retrospective cohort review was performed to identify all patients at a single institution between 2012-2020 who underwent 1- or 2- level ACDR or MI-PCF from C3-C7 with a minimum follow-up of 24 months. Patient demographics, perioperative data, postoperative complications, and revisions were analyzed. Patient reported outcome measures including VAS and NDI scores were compared. RESULTS: The ACDR group had a significantly greater mean operative time (99.8 minutes vs 79.2 minutes, p<.001), but comparable estimated blood loss and length of stay following surgical intervention (p=.899). The overall complication rate was significantly greater in the ACDR group than the MI-PCF group (24.4% vs 6.2%; p=.003) but was largely driven by approach-related dysphagia in 20.9% of ACDR patients. The MI-PCF group had significantly greater revision rates (13.6% vs 1.2%; p=.002) with an average time to revision of 20.7 months in the MI-PCF group compared to 40.3 months in the ACDR group. The ACDR cohort had significantly greater improvements in NDI scores at the final follow-up (25.0 vs 21.3, p<.001). CONCLUSION: Our results suggest that ACDR offer clinically relevant advantages over MI-PCF in terms of long-term revision rates despite an increased approach-related risk of transient postoperative dysphagia. Additionally, patients in the ACDR cohort achieved greater mean improvements in NDI scores but these results may have limited clinical significance due to inability to reach minimally clinically important difference (MCID) thresholds.

Should patient eligibility criteria for cervical disc arthroplasty (CDA) be expanded? A retrospective cohort analysis of relatively contraindicated patients undergoing CDA.

BACKGROUND CONTEXT: Cervical disc arthroplasty (CDA) is a safe and effective alternative to anterior cervical discectomy and fusion (ACDF) in the treatment of various degenerative pathologies with advantages of motion preservation and lower rates of adjacent segment degeneration (ASD). Absolute contraindications for CDA have been well outlined in order to prevent adverse outcomes in patients. However, in cases of patients with relative contraindications (kyphotic deformity, prior cervical surgery, etc.), there remains controversy. There is minimal literature evaluating long-term outcomes in this patient population. PURPOSE: To compare long-term clinical and functional outcomes of CDA in typical patients versus those with relative contraindications. DESIGN: Retrospective cohort review. PATIENT SAMPLE: Eighty-nine patients were included in the study: 55 (no contraindications) in Group 1 and 34 (relatively contraindicated) in Group 2 and 26 (preoperative segmental kyphosis) in Group 3. OUTCOME MEASURES: (1) Patient demographics; (2) perioperative data; (3) rates of complications and revisions; (5) visual analogue scale (VAS), and neck disability index (NDI) scores. METHODS: Patients were placed in the relatively contraindicated cohort if they possessed at least one of the following: (1) segmental kyphosis of 5° to 10°, (2) significant loss of disc height (between 50% and 75% of initial measurements or 1.5-3mm), (3) bridging osteophytes, and (4) prior cervical spine surgery based on preoperative cervical radiographs. The other cohort included patients without any relative contraindication who underwent CDA over the same time frame. Additionally, a subgroup analysis was used to compare those without any contraindications to those with only preoperative segmental kyphosis. Patients were included in this study if they met the following criteria: over 18 years of age, minimum follow-up of 24 months, and availability of complete medical records. Patient demographics, levels operated on, and perioperative outcomes were assessed between the two groups. Revision and complication rates were recorded. Functional outcomes scores were compared using VAS and NDI scores at 6-months, 12-months and final follow-up. RESULTS: Mean follow-up was 40.8 months in Group 1 and 38.3 months in Group 2 (p=.569). Complication rates were 21.8% in Group 1 and 26.4% in Group 2 (p=.615). Complication rates in a comparison between Groups 1 and 3 were statistically insignificant (p=.383). The most common complication was transient approach-related postoperative dysphagia (Group 1: 20% vs Group 2: 23.5%, p=.693). No significant differences were observed in the rates of transient dysphonia (Group 1: 0.0% vs Group 2: 2.9%, p=.201), adjacent segment degeneration (ASD) (Group 1: 1.8% vs Group 2: 0.0%, p=.429), infection (Group 1: 1.8% vs Group 2: 2.9%, p=.712), heterotopic ossification (Group 1: 49.1% vs Group 2: 50.0%, p=.934) or spontaneous fusion (Group 1: 1.8% vs Group 2: 2.9%, p=.728). No revision surgeries were observed in either cohort. All three groups demonstrated significant improvements in their VAS and NDI scores compared with preoperative measurements (p<.001), but no significant differences were found in the degree of improvement between groups at any point in time. CONCLUSIONS: Our study found no significant differences in clinical and functional outcomes between patients undergoing 1- and 2-level CDA with relative contraindications versus typical patients. These findings suggest that patient eligibility criteria for CDA may warrant expansion. However, future prospective studies over a longer period of follow-up are necessary to corroborate our results.

The 5-Factor Modified Frailty Index is Associated With Increased Risk of Reoperations and Adjacent Level Disease Following Single-Level Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine the predictive capability between the 5-factor modified frailty index (mFI-5) scores and adverse clinical and radiographic outcomes following single-level transforaminal lumbar interbody fusion (TLIF). METHODS: All patients over the age of 50 undergoing single-level open or minimally invasive TLIF from 2012 to 2021 with a minimum follow-up of 1 year were identified. Deformity, trauma, emergency, and tumor cases were excluded as were patients undergoing revision surgeries. An mFI-5 score was computed for each patient using a set of five factors which included hypertension requiring medication, chronic obstructive pulmonary disease, diabetes mellitus, congestive heart failure, and partially or fully dependent functional status. Univariate and multivariate logistic regression analysis were performed to evaluate the impact of mFI-5 scores on readmissions, reoperations, and postoperative complications. RESULTS: 156 patients were included and grouped according to their level of frailty: no-frailty (mFI = 0, n = 67), mild frailty (mFI = 1, n = 59), and severe frailty (mFI = 2+, n = 30). Multivariate analysis found high levels of frailty (mFI = 2+) to be independent predictors of reoperation (OR: 16.9, CI: 2.7 - 106.9, P = .003) and related readmissions (OR = 16.5, CI: 2.6 - 102.7, P = .003) as compared to the no-frailty group. An mFI-5 score of 2+ was also predictive of any complication (OR = 4.5, CI: 1.4 - 14.3, P = .01) and adjacent segment disease (ASD) (OR = 12.5, CI: 1.2 - 134.0, P = .037). CONCLUSION: High levels of frailty were predictive of related readmissions, reoperations, any complications, and ASD in older adult patients undergoing single-level TLIF.

The 5-factor modified Frailty Index (mFI-5) predicts adverse outcomes after elective Anterior Lumbar Interbody Fusion (ALIF).

Background: The 5-factor modified frailty index (mFI-5) has been shown to be a concise and effective tool for predicting adverse events following various spine procedures. However, there have been no studies assessing its utility in patients undergoing anterior lumbar interbody fusion (ALIF). Therefore, the aim of this study was to analyze the predictive capabilities of the mFI-5 for 30-day postoperative adverse events following elective ALIF. Methods: The National Surgical Quality Improvement Program (NSQIP) database was queried from 2010 through 2019 to identify patients who underwent elective ALIF using Current Procedural Terminology (CPT) codes in patients over the age of 50. The mFI-5 score was calculated using variables for hypertension, congestive heart failure, comorbid diabetes, chronic obstructive pulmonary disease, and partially or fully dependent functional status which were each assigned 1 point. Univariate analysis and multivariate logistic regression models were utilized to identify the associations between mFI-5 scores, and 30-day rates of overall complications, readmissions, reoperations, and mortality. Results: 11,711 patients were included (mFI-5=0: 4,026 patients, mFI-5=1: 5,392, mFI-5=2: 2,102, mFI-5=3+: 187. Multivariate logistic regression revealed that mFI-5 scores of 1 (OR: 2.2, CI: 1.2-4.2, p=0.02), 2 (OR: 3.6, CI: 1.8-7.3, p<0.001), and 3+ (OR: 7.0, CI: 2.5-19.3, p<0.001) versus a score of 0 were significant predictors of pneumonia. An mFI-5 score of 2 (OR: 1.3; CI: 1.01-1.6, p=0.04), and 3+ (OR: 1.9; CI: 1.1-3.1; p=0.01) were both independent predictors of related readmissions. An mFI score of 3+ was an independent predictor of any complication (OR: 1.5, CI: 1.01-2.2, p=0.004), UTI (OR: 2.4, CI: 1.1-5.2, p=0.02), and unplanned intubation (OR: 4.5, CI: 1.3-16.1, p=0.02). Conclusions: The mFI-5 is an independent predictor for 30-day postoperative complications, readmissions, UTI, pneumonia, and unplanned intubations following elective ALIF surgery in adults over the age of 50.

Numerical Analysis of Temperature Distribution Profiles of Breast Tissues with Cyst and Tumor of Different sizes and Locations.

Breast cancer causes more deaths among all types of cancers. Efforts have been put to study the change in temperature distribution profile of the breast in presence of an abnormality. By applying Pennes's bio-heat equation, a 2D finite element model is developed for the heat transfer mechanism. Surface temperature gradients due to the presence of abnormalities at various depths and sizes are analyzed. The results show that the presence of a cyst decreases the temperature whereas the occurrence of tumor increases the temperature inside the breast. It is observed that abnormal tissue having a radius less than 1.5cm and depth greater than 5cm, has a negligible effect on the surface temperature profile. The highest change in surface temperature is observed when a cyst or tumor is larger and present near the skin. The simulation results help in the better interpretation of the thermal images and calibration of infrared camera. This study could be helpful in the early diagnosis of breast cancer.

Two-Attending Surgeon Teams Improve Outcomes of Single-Level Anterior Cervical Discectomy and Fusion.

Given the shift toward value-based healthcare, strategies that decrease risk in commonly performed procedures such as anterior cervical discectomy and fusion (ACDF) are of interest. The objective of this study was to analyze the effect of a two-attending surgeon team on the outcomes of patients undergoing single-level ACDF. A retrospective matched-cohort study of patients undergoing single-level ACDF for degenerative cervical spondylosis, with minimum 2-year follow-up was performed. Patients were subdivided into two cohorts: cases with procedures performed by one attending surgeon assisted by a resident physician and cases with procedures performed by an attending surgeon with another attending surgeon as first-assist. Patients were matched by age, sex, body mass index, smoking status, American Society of Anesthesia grade and Charlson Comorbidity Index. Perioperative data and complications were compared. Standard binomial and categorical comparative analysis were performed. Forty-two patients were included (21 in each group). There were 22 males and 20 females, with a mean age of 47.7 years and mean follow-up of 43.4 months. There were no differences in any demographic variable between groups, indicating successful matching. Cohort B had decreased anesthesia time (114.9 vs. 157.1 minutes, P < 0.001), operative time (58.1 vs. 98.9 minutes, P < 0.001) and blood loss (14.8 vs. 24.3 mL, P = 0.012). There were no significant differences in terms of post-operative complications including dysphagia, wound infection, neurologic or cardiovascular related complications. A two-attending surgeon team significantly reduces anesthesia time, surgical time, and blood loss in single-level ACDF procedures without an increase in complications or a decrease in fusion rates.

Obesity Does Not Adversely Affect Long-term Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Matched Cohort Analysis.

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is an established technique for the treatment of degenerative spine disease. The larger body habitus of obese patients increases the intraoperative complexity of MI-TLIF. Therefore, it is unclear whether this procedure is appropriate for this population. The goal of this study was to compare postoperative outcomes for obese patients vs nonobese patients undergoing MI-TLIF through a matched cohort analysis. A retrospective review was performed to identify patients who underwent MI-TLIF at a single institution with a minimum follow-up of 5 years. Patients were divided into 2 cohorts: nonobese (body mass index <30 kg/m2) and obese (body mass index ≥30 kg/m2). Each cohort was matched for age, sex, and levels operated. Perioperative data and patient-reported outcomes were compared. Radiographic outcomes were measured at final follow-up. Standard binomial and categorical comparative analyses were performed. A total of 148 patients were included. Of obese patients, 17.6% required revision surgery compared with 16.2% of nonobese patients (P=.826). Both cohorts had a similar proportion of pelvic incidence-lumbar lordosis mismatch correction (P=.780). Mean change in functional outcome scores for each cohort did not differ significantly. Obese patients had clinically minor but statistically significantly greater blood loss and longer operative times than nonobese patients (P<.001). Obese and non-obese patients undergoing MI-TLIF showed no long-term differences in revision rate, radiologic outcome, or functional outcome after long-term follow-up. Obese patients had slightly greater blood loss and longer operative times. Our findings suggest that MI-TLIF is an appropriate alternative to traditional open lumbar fusion for obese patients. [Orthopedics. 2022;45(4):203-208.].

Should we bridge the cervicothoracic junction in long cervical fusions? A meta-analysis and systematic review of the literature.

OBJECTIVE: Long posterior cervical decompression and fusion (PCF) is commonly performed to surgically treat patients with multilevel cervical pathology. In cases in which constructs may necessitate crossing the cervicothoracic junction (CTJ), recommendations for appropriate caudal fusion level vary in the literature. The aim of this study was to report the clinical and radiological outcomes of multilevel PCFs ending at C7 versus those crossing the CTJ. METHODS: A systematic search of PubMed, CINAHL Plus, and Scopus was conducted to identify articles that evaluated clinical and radiological outcomes of long PCFs that ended at C7 (cervical group) or crossed the CTJ (thoracic group). Based on heterogeneity, random-effects models of a meta-analysis were used to estimate the pooled estimates and the 95% confidence intervals. RESULTS: PCF outcome data of 1120 patients from 10 published studies were included. Compared with the cervical group, the thoracic group experienced greater mean blood loss (453.0 ml [95% CI 333.6-572.5 ml] vs 303.5 ml [95% CI 203.4-403.6 ml]), longer operative times (235.5 minutes [95% CI 187.7-283.3 minutes] vs 198.5 minutes [95% CI 157.9-239.0 minutes]), and a longer length of stay (6.7 days [95% CI 3.3-10.2 days] vs 6.2 days [95% CI 3.8-8.7 days]); however, these differences were not statistically significant. None of the included studies specifically investigated factors that led to the decision of whether to cross the CTJ. The cervical group had a mean fusion rate of 86% (95% CI 71%-94%) compared with the thoracic group with a rate of 90% (95% CI 81%-95%). Of patients in the cervical group, 17% (95% CI 10%-28%) required revision surgery compared with 7% (95% CI 4%-13%) of those in the thoracic group, but this difference was not statistically significant. The proportion of patients who experienced complications in the cervical group was found to be 28% (95% CI 12%-52%) versus 14% (95% CI 7%-26%) in the thoracic group; however, this difference was not statistically significant. There was no significant difference (no overlap of 95% CIs) in the incidence of adjacent-segment disease, pseudarthrosis, or wound-related complications between groups. CONCLUSIONS: This meta-analysis suggests similar clinical and radiographic outcomes in multilevel PCF, regardless of inclusion of the CTJ. The lowest instrumented level did not significantly affect revision rates or complications. The ideal stopping point must be tailored to each patient on an individualized basis.

Metal-on-metal versus metal-on-plastic artificial discs in two-level anterior cervical disc replacement: a meta-analysis with follow-up of 5 years or more.

BACKGROUND CONTEXT: Although highlighted in joint arthroplasty studies, long-term outcomes between differing biomaterial composites, such as metal-on-metal (MoM) and metal-on-plastic (MoP) in anterior cervical disc replacement (ACDR) have not been thoroughly investigated. PURPOSE: The purpose of this study was to evaluate the patient-reported clinical outcomes, overall reoperation rates, complications, and rates of ASD of MoM versus MoP artificial discs in two-level ACDR for the treatment of cervical DDD. STUDY DESIGN/SETTING: Meta-analysis and systematic review. PATIENT SAMPLE: Nine hundred eighty patients (442 MoM, 538 MoP) across seven studies. OUTCOME MEASURES: Patient reported clinical outcomes (NDI, VAS-n, VAS-a), overall reoperation rates, complications, and rates of ASD. METHODS: A systematic search strategy of three electronic databases (PubMed, CINAHL Plus, and SCOPUS) was conducted utilizing terms related to two-level ACDR. All studies included had a sample size of >10 patients, had a minimum 5-year follow-up, and reported data on adjacent segment disease. Cadaver studies, non-English manuscripts, articles with less than 5-year follow-up and studies in which only single-level ACDR was investigated were excluded. A total of seven studies were included in this analysis. Studies were analyzed for demographic data, clinical outcome scores (NDI, VAS-neck, and VAS-arm), overall reoperation rates, complications, and rates of ASD. A random-effects model of meta-analysis was used for groups that were determined to be heterogenous and a fixed-effects model was utilized for groups that were not. An overlap of 95% confidence intervals suggests no statistically significant difference at the p<.05 level. RESULTS: Seven studies were included with data on 980 patients (442 MoM, 538 MoP). The study population was 52.84% female, with a mean age of 48.01 years, and a mean follow-up of 85.66 months. The mean improvement in NDI was 34.42 (95% CI, 32.49-36.36) and 29.72 (95% CI, 27.15-32.29) for the MoM and MoP groups, respectively. The mean improvement in VAS-neck was 11.20 (95% CI, 10.69-11.70) and 8.78 (95% CI, 7.81-9.74) for the MoM and MoP groups, respectively. The mean improvement in VAS-arm was 10.73 (95% CI, 9.83-11.63) and 8.49 (95% CI, 7.59-9.39) for the MoM and MoP groups, respectively. 3.85% (95% CI, 2.40-6.10) of patients who underwent ACDR with a MoM implant required reoperation compared to 5.33% (95% CI, 3.68-7.65) of patients with a MoP implant. Heterotopic ossification and dysphagia were the most common complications in both groups. The MoM cohort showed a higher incidence of HO (72.62% vs. 21.07%), but a lower incidence of dysphagia (0.96% vs. 16.31%) compared to the MoP cohort. The MoM cohort had a larger proportion of patients with ASD who underwent subsequent surgery at an adjacent level (7.89% MoM versus 1.91% MoP). CONCLUSIONS: Our present meta-analysis suggests that the use of MoM artificial discs in two-level ACDR results in superior clinical outcome score improvement, but higher rates of ASD requiring secondary surgery compared to MoP discs after a follow-up period of 5 years or more.

Does Percutaneous Lumbosacral Pedicle Screw Instrumentation Prevent Long-Term Adjacent Segment Disease after Lumbar Fusion?

STUDY DESIGN: Retrospective cohort study. PURPOSE: To assess long-term clinical outcomes of adjacent segment disease (ASD) in patients who underwent lumbar interbody fusion with percutaneous pedicle screw (PS) instrumentation. OVERVIEW OF LITERATURE: ASD is a well-known sequela of spinal fusion, and is reported to occur at a rate of 2%-3% per year. There is debate as to whether ASD is a result of the instrumentation and fusion method or is the natural history of the patient's disease. Minimally invasive percutaneous PS augmentation of lumbar interbody fusion aims to prevent the disruption of posterior soft tissue stabilizers. METHODS: From 2004-2014, 419 consecutive patients underwent anterior, lateral, or minimally invasive transforaminal lumbar interbody fusion with percutaneous PS placement at a single institution. The mean follow-up was 4.5 years. The primary outcome measure was reoperation due to ASD. Patients were divided into two cohorts: those who underwent revision surgery secondary to ASD and those who did not require further surgery. Radiographic parameters were performed using postoperative radiographs. Patients with a pelvic incidence-lumbar lordosis (PI-LL) mismatch >10° were noted. RESULTS: Revision proportion secondary to ASD was 4.77% (n=20). Mean time to revision surgery was 2.5 years. Revision rate secondary to ASD was 1.1% per year. Patients who developed ASD were younger than those who did not (50.5 vs. 56.9 years, p=0.015). There was no difference in number of levels fused between cohorts. Revision proportion secondary to ASD was similar between approaches (anterior, lateral, minimally invasive). There was no significant difference in PI-LL mismatch between those who underwent revision for ASD and those who did not (22.2% vs. 18.8%, p=0.758). CONCLUSIONS: ASD rates in patients who underwent percutaneous PS placement were lower than those previously published after open PS placement, possibly related to greater preservation of the posterior stabilizing elements of the lumbar spine.

Primary Extramedullary, Extradural Cervical Spine Seminoma.

While extragonadal seminomas resulting in spinal cord compression are rarely reported in the literature, most have been treated with surgical decompression followed by radiation therapy. In this report, we present the unique and interesting case of a 38-year-old man who initially presented as an outpatient with a chief complaint of axial neck pain and lateral thoracic wall pain. After an extensive malignancy workup, he was diagnosed with a primary cervical spine seminoma and was treated with a C6-T1 laminectomy with posterior spinal instrumentation from C5 to T2. He has since undergone chemotherapy with cisplatin, vinblastine, and bleomycin, and at 24-month follow-up, he remains asymptomatic with no signs of recurrent disease.

Sinus Floor Augmentation in Presence of Mucocele Eroding Maxillary Sinus Wall: A Case Report With 3 Years Follow-Up.

INTRODUCTION: The maxillary mucocele is a slow-growing aggressive lesion and a mucous-containing sac lined with epithelium that occurs due to ductal obstruction and self-limiting injury. Rarely, it may be associated with non-specific symptoms. It is characterized by bone resorption due to its expanding behavior. Reduced height of bone and sinus pneumatization associated with pathologic lesions located in the floor of maxillary sinus may impede sinus augmentation. Therefore, careful diagnosis and management of pathology before sinus floor elevation is important in determining its recurrence and prognosis. CASE PRESENTATION: We reported a case with small mucocele on right pneumatized antrum with insufficient residual bone height for implant placement. Radiograph in the region of teeth #3 and #4 revealed a homogeneous solitary radiopaque mass. Cone-beam computed tomography revealed irregular osteolysis of the lateral wall of the sinus. It was excised through Caldwell-Luc technique and simultaneous sinus augmentation was performed. Later, delayed implant restoration was performed. No complication or recurrence was reported during 36 months of follow-up. CONCLUSIONS: The excision of mucocele on sinus floor and simultaneous sinus augmentation obviates the need for the extended treatment period. The clinician must be habituated with the anatomy and pathology of the maxillary sinus to evade any non-essential complications following lateral sinus floor augmentation procedure. A diminutive mucocele should not be regarded as a contraindication for sinus augmentation; sometimes it manifests with bone erosion. The prompt diagnosis and careful evaluation are needed to avoid future complications during implant therapy.

Minimally Invasive Posterior Cervical Foraminotomy as an Alternative to Anterior Cervical Discectomy and Fusion for Unilateral Cervical Radiculopathy: A Systematic Review and Meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: The aim of this study was to evaluate clinical outcomes, complications, and reoperations of minimally invasive posterior cervical foraminotomy (MI-PCF) for unilateral cervical radiculopathy without myelopathy, in comparison to anterior cervical decompression and fusion (ACDF). SUMMARY OF BACKGROUND DATA: ACDF is a standard treatment for cervical radiculopathy secondary to lateral disc herniation or foraminal stenosis. Recent studies have suggested MI-PCF to be an effective alternative to ACDF. However, concern for reoperation and whether similar improvements in clinical outcomes can be achieved has led to a debate in the literature. METHODS: We comprehensively searched PubMed, CINAHL Plus, and SCOPUS utilizing terms related to MI-PCF. Two independent reviewers assessed potential studies and extracted data on clinical outcome scores (neck disability index [NDI], visual analog scale [VAS]-neck, and VAS-arm), reoperation proportion, and complications. Studies included were on noncentral cervical pathology, published in the last 10 years, had a sample size of >10 patients, and reported data on minimally invasive techniques for posterior cervical foraminotomy. Heterogeneity and publication bias analyses were performed. The pooled proportions of each outcome were compared to those of ACDF obtained from two previously published studies. RESULTS: Fourteen studies were included with data of 1216 patients. The study population was 61.8% male, with a mean age of 51.57 years, and a mean follow-up of 30 months. MI-PCF resulted in a significantly greater improvement in VAS-arm scores compared to ACDF, and similar improvements in VAS-neck and NDI scores. Proportions of complications and reoperations were similar between the two cohorts. The most common complications were transient neuropraxia, wound-related, and durotomy. CONCLUSION: Our findings suggest that MI-PCF may be utilized as a safe and effective alternative to ACDF in patients with unilateral cervical radiculopathy without myelopathy, without concern for increased reoperations or complications. LEVEL OF EVIDENCE: 3.

Short-Segment Fixation With Percutaneous Pedicle Screws in the Treatment of Unstable Thoracolumbar Vertebral Body Fractures.

Clinical care of patients with unstable thoracolumbar vertebral body fractures may be challenging, especially in the setting of polytrauma patients who require other acute intervention. Compared with the traditional open approach, percutaneous short-segment fixation constructs place less surgical burden on patients regarding operative time and blood loss. Between 2008 and 2012, 32 patients with a mean age of 49 years (range, 19-80 years) underwent percutaneous short-segment fixation at the authors' institution and had a minimum of 6 months of complete clinical and radiographic follow-up. Load-sharing classification scores were determined. Outcomes evaluated included anterior body height, posterior body height, local kyphosis, regional kyphosis, thoracolumbar junctional kyphosis, mean operative time, and total blood loss. Standard binomial and categorical comparative analyses were performed. All load-sharing classification scores were 7 or less, and 11 of the 32 patients were polytrauma patients requiring surgery. No difference was seen between preoperative and late measurements of anterior body height, posterior body height, local kyphosis, regional kyphosis, or thoracolumbar junctional kyphosis. There were no complications, revisions, or anterior corpectomies. Only 2 patients (6%) underwent elective removal of hardware at 1 year. Mean operative time was 43 minutes (range, 33-56 minutes), and mean estimated blood loss was less than 50 mL. Percutaneous short-segment fixation prevented loss of vertebral body height and progression of kyphosis in the treatment of unstable thoracolumbar fractures with load-sharing classification scores of 7 or less. This study shows that these fractures with a load-sharing classification score of 6 and 7 may be stabilized using fewer screws than traditional methods in some patients and allow polytrauma patients to undergo other acute treatment. [Orthopedics. 2018; 41(6):e802-e806.].

Risk Factors for Pseudarthrosis in Minimally-Invasive Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort study (level of evidence: 4). PURPOSE: To describe the potential comorbid, operative, and radiographic risk factors for the development of clinically-relevant pseudarthrosis following minimally-invasive transforaminal lumbar interbody fusion (MIS-TLIF). OVERVIEW OF LITERATURE: MIS-TLIF has shown long-term clinical outcomes with decreased perioperative morbidity and earlier return to work, similar to those of open TLIF. However, unsuccessful fusion still remains a concern. The impacts of various patient, operative, and radiographic risk factors have not been evaluated for their potential association with pseudarthrosis related to MIS-TLIF. METHODS: Between 2012 and 2015, 204 consecutive patients underwent one or two-level MIS-TLIF at St. Joseph's University Medical Center, Paterson, NJ, USA; they had a minimum of 1 year of follow-up. The patients were divided into two cohorts: those who developed clinically-relevant pseudarthrosis and those who did not. Clinically-relevant pseudarthrosis was determined by both evidence on computed tomography and presence of continued clinical symptoms at 1-year follow-up. RESULTS: Revision surgery was the only identified non-radiographic factor associated with pseudarthrosis. Disc angle had the highest (R 2=0.8), followed by anterior disc height (R 2=0.79). Although posterior disc height and the ratio of anterior to posterior disc height showed a marked relationship with the outcome, the R 2-values were <0.3, thus indicating a less-strong correlation. The overall pseudarthrosis rate was 8%. No statistically significant differences were identified between the two cohorts with respect to mean age, sex, medical comorbidities, smoking status, or number of levels fused. CONCLUSIONS: Clinically-relevant pseudarthrosis is not uncommon following MIS-TLIF. In the current study, undergoing revision surgery, disc angle, and anterior disc height were observed to be associated with clinically-relevant pseudarthrosis. This study demonstrated that the patient population may benefit from an alternate approach.

Minimally invasive posterior cervical foraminotomy with tubes to prevent undesired fusion: a long-term follow-up study.

OBJECTIVE: The objective of this study was to compare anterior cervical discectomy and fusion (ACDF) and minimally invasive posterior cervical foraminotomy (MI-PCF) with tubes for the treatment of cervical radiculopathy in terms of the 1) overall revision proportion, 2) index and adjacent level revision rates, and 3) functional outcome scores. METHODS: The authors retrospectively reviewed the records of consecutive patients who had undergone ACDF or MI-PCF at a single institution between 2009 and 2014. Patients treated for cervical radiculopathy without myelopathy and with a minimum 2-year follow-up were compared according to the procedure performed for their pathology. Primary outcome measures included the overall rate of revision with fusion and overall revision proportion as well as the rate of index and adjacent level revisions per year. Secondarily, self-reported outcome measures-Neck Disability Index (NDI) and visual analog scale (VAS) for arm (VASa) and neck (VASn) pain-at the preoperative and postoperative evaluations were analyzed. Standard binomial and categorical comparative analyses were performed. RESULTS: Forty-nine consecutive patients were treated with MI-PCF, and 210 consecutive patients were treated with ACDF. The mean follow-up for the MI-PCF cohort was 42.9 ± 6.6 months (mean ± SD) and for the ACDF cohort was 44.9 ± 10.3 months. There was no difference in the overall revision proportion between the two cohorts (4 [8.2%] of 49 MI-PCF vs. 12 [5.7%] of 210 ACDF, p = 0.5137). There was no difference in the revision rate per level per year (3.1 vs. 1.7, respectively, p = 0.464). Moreover, there was no difference in the revision rate per level per year at the index level (1.8 vs. 0.7, respectively, p = 0.4657) or at an adjacent level (1.3 vs. 1.1, p = 0.9056). Neither was there a difference between the cohorts as regards the change from preoperative to final postoperative functional outcome scores (NDI, VASa, VASn). CONCLUSIONS: Minimally invasive PCF for the treatment of cervical radiculopathy demonstrates rates of revision at the index and adjacent levels similar to those following ACDF. In order to confirm the positive efficacy and cost analysis findings in this study, future studies need to extend the follow-up and show that the rate of revision with fusion does not increase substantially over time.

Incidence of Neuraxial Abnormalities Is Approximately 8% Among Patients With Adolescent Idiopathic Scoliosis: A Meta-analysis.

BACKGROUND: Several studies have sought to address the role of routine preoperative MRI in patients with adolescent idiopathic scoliosis (AIS) undergoing deformity correction. Despite similar results regarding the prevalence of neuraxial anomalies detected on MRI, published conclusions conflict and give opposing recommendations. Lack of consensus has led to important variations in use of MRI before spinal surgery for patients with AIS. QUESTIONS/PURPOSES: This systematic review and meta-analysis of studies about patients with AIS evaluated (1) the overall proportion of neuraxial abnormalities; (2) the patient factors and curve characteristics that may be associated with abnormalities; and (3) the proportion of patients who underwent neurosurgical intervention before scoliosis surgery and the kinds of neuraxial lesions that were identified. METHODS: We performed a search of four electronic databases (PubMed, EMBASE, CINAHL Plus, and SCOPUS) utilizing search terms related to routine MRI and AIS, yielding 206 articles. Studies included had at least 20 participants, patients with ages 11 to 21 years, and a Methodological Index for Non-Randomized Studies (MINORS) study quality score of 8 and 16 points for noncomparative and comparative studies, respectively. Non-English manuscripts, animal studies, and those that did not include patients with AIS solely were excluded. Eighteen articles with 4746 patients were included for analysis of the overall proportion of neuraxial abnormalities, 12 articles with 3028 patients for analysis by sex, eight articles with 1603 patients for right main thoracic curve, eight articles with 665 patients for a left main thoracic curve, and 13 articles with 3063 patients and 230 (7.5%) abnormalities for number of neurosurgical interventions before scoliosis correction. The mean MINORS score for studies included was 14 (range, 10-20). Each study was analyzed for the proportion of patients identified with neuraxial abnormalities and associations with specific demographics. We determined the proportion of patients who underwent surgical interventions before scoliosis surgery as well as the types of neuraxial lesions identified. The articles were assessed for heterogeneity and publication bias. Because all groups were determined to be heterogeneous, a random-effects model was used for each group in this meta-analysis; with this analysis, an overlap of 95% confidence intervals suggests no difference at the p < 0.05 level, but this analytic approach does not provide p values. RESULTS: The pooled proportion of neuraxial abnormalities detected on MRI was 8% (95% confidence interval [CI], 6%-12%). With the numbers available, we found no difference in the proportion of male and female patients with neuraxial abnormalities (18% [95% CI, 11%-29%] versus 9% [95% CI, 6%-12%], respectively). Likewise, there was no difference in the proportion of pooled neuraxial abnormalities in right and left curves (9% [95% CI, 6%-14%] versus 15% [95% CI, 5%-35%], respectively). In the subset of abnormalities analyzed for number of neurosurgical interventions before scoliosis correction, the pooled proportion showed that 33% (95% CI, 24%-43%) underwent neurosurgical intervention before deformity correction. The most common abnormalities of the 367 found on MRI were syringomyelia in 127 patients (35%), Arnold-Chiari Type 1 malformation with syrinx in 103 patients (28%), and isolated Arnold-Chiari Type 1 malformation in 91 patients (25%). CONCLUSIONS: The proportion of patients with AIS who have neuraxial abnormalities is high (8%) and a large number undergo surgical intervention before scoliosis reconstruction. We did not find any particular demographic variables that indicated an increased risk of abnormality. Clinicians should consider advanced imaging before surgical intervention in the treatment of a patient with an idiopathic diagnosis. Preventable variables need to be identified by future studies to establish a better working treatment protocol for these patients. LEVEL OF EVIDENCE: Level III, diagnostic study.