Preoperative weight loss before total hip arthroplasty negatively impacts postoperative outcomes.

BACKGROUND: Obesity adversely impacts outcomes of total hip arthroplasty (THA), leading surgeons to impose body mass index cutoffs for patient eligibility and encourage preoperative weight loss. This study aimed to determine if preoperative weight loss impacts outcomes of THA in the general patient population and if it mitigates poor outcomes in obese patients. METHODS: Patients who underwent THA from 2013-2020 were identified in the National Surgical Quality Improvement Program (NSQIP) database. Patients were stratified by weight loss of >10% of body weight over the preceding 6 months. We used multivariable linear and logistic regression models, adjusted for age, sex, race/ethnicity, and comorbidities, to examine the effect of significant preoperative weight loss on 30-day outcomes after THA in the general and obese patient populations. RESULTS: In the overall population, patients who lost significant weight preoperatively had significantly increased length of stay, were more likely to have a non-home discharge, return to the operating room, or be readmitted, and were more likely to experience numerous medical complications. In the obese population, patients who lost significant weight preoperatively had significantly increased length of stay and were more likely to require a transfusion or experience any medical complication. DISCUSSION: Rapid significant preoperative weight loss is not associated with improved postoperative outcomes after THA in the obese population and is associated with worse outcomes in the general population. Arthroplasty surgeons should balance these risks with the risks of obesity when advising patients about preoperative weight loss prior to THA. LEVEL OF EVIDENCE: III.

Racial, Socioeconomic, and Payer Status Disparities in Utilization of Total Ankle Arthroplasty Compared to Ankle Arthrodesis.

Total ankle arthroplasty is increasingly being used for the treatment of ankle osteoarthritis when compared to arthrodesis. However, there has been limited investigation into disparities in utilization of these comparable procedures. This study examined racial/ethnic, socioeconomic, and payer status disparities in the likelihood of undergoing total ankle arthroplasty compared with ankle arthrodesis. Patients with a diagnosis of ankle osteoarthritis from 2006 through 2019 were identified in the National Inpatient Sample, then subclassified as undergoing total ankle arthroplasty or arthrodesis. Multivariable logistic regression models, adjusted for hospital location, primary or secondary osteoarthritis diagnosis, and patient characteristics (age, sex, infection, and Elixhauser comorbidities), were used to examine the effect of race/ethnicity, socioeconomic status, and payer status on the likelihood of undergoing total ankle arthroplasty versus arthrodesis. Black and Asian patients were 34% and 41% less likely than White patients to undergo total ankle arthroplasty rather than arthrodesis (p < .001). Patients in income quartiles 3 and 4 were 22% and 32% more likely, respectively, than patients in quartile 1 to undergo total ankle arthroplasty rather than arthrodesis (p = .001 and p = .01, respectively). In patients <65 years of age, privately insured and Medicare patients were 84% and 37% more likely, respectively, than Medicaid patients to undergo total ankle arthroplasty rather than arthrodesis (p < .001). Racial/ethnic, socioeconomic, and payer status disparities exist in the likelihood of undergoing total ankle arthroplasty versus arthrodesis for ankle osteoarthritis. More work is needed to establish drivers of these disparities and identify targets for intervention, including improvements in parity in relative procedure utilization.

Systematic YouTube Review - Trigger Finger Release.

Background: With lack of regulation and incentivisation on YouTube for high-quality healthcare information, it is important to objectively evaluate the quality of information on trigger finger - a common condition for hand surgeon referral. Methods: YouTube was queried (11/21/2021) for videos on trigger finger release surgery. Videos were excluded if they were about unrelated topics or not in English. The most viewed 59 videos were categorised by source as physician or non-physician. Two independent reviewers quantified the reliability, quality and content of each video, with inter-rater reliability assessed using Kohen's Kappa test. Reliability was assessed using the Journal of the American Medical Association (JAMA) score. Quality was assessed using the DISCERN score with high-quality videos defined as those with scores in the sample upper 25th percentile. Content was assessed using the informational content score (ICS) with scores in the sample upper 25th percentile indicating more complete information. Two-sample t-tests and logistic regression were used to assess variations between sources. Results: Videos by physicians had higher DISCERN quality (42.6 ± 7.9, 36.4 ± 10.3; p = 0.02) and informational content (5.8 ± 2.6, 4.0 ± 1.7; p = 0.01) scores compared to those by non-physician sources. Videos by physicians were associated with increased odds of high-quality (Odds Ratio [OR] 5.7, 95% Confidence Interval [95% CI] 1.3-41.3) and provided more complete patient information (OR 6.3, 95% CI 1.4-48.9). The lowest DISCERN sub-scores for all videos were discussion of the uncertainties and risks associated with surgery. The lowest ICS for all videos were in the diagnosis of trigger finger (11.9%) and non-surgical prognosis (15.3%). Conclusions: Physician videos have more complete and higher quality information on trigger finger release. Additionally, discussion of treatment risks, areas of uncertainty, the diagnostic process, non-surgical prognosis and transparency on references used were identified as lacking content. Level of Evidence: Level III (Therapeutic).

Effects of L1 adhesion molecule agonistic mimetics on signal transduction in neuronal functions.

The L1 cell adhesion molecule plays an essential role in neural development and repair. It is not only a 'lock and key' recognition molecule, but an important signal transducer that stimulates regenerative-beneficial cellular functions such as neurite outgrowth, neuronal cell migration, survival, myelination, and synapse formation. Triggering L1 functions after neurotrauma improves functional recovery. In addition, loss-of-function mutations in the L1 gene lead to the L1 syndrome, a rare, X-linked neurodevelopmental disorder with an incidence of approximately 1:30,000 in newborn males. To use L1 for beneficial functions, we screened small compound libraries for L1 agonistic mimetics that trigger L1 functions and improve conditions in animal models of neurotrauma and the L1 syndrome. To understand the mechanisms underlying these functions, it is important to gain a better understanding of L1-dependent cellular signaling that is triggered by the L1 agonistic mimetics. We tested the cell signaling features of L1 agonistic mimetics that contribute to neurite outgrowth and neuronal migration. Our findings indicates that L1 agonistic mimetics trigger the same cell signaling pathways underlying neurite outgrowth, but only the L1 mimetics tacrine, polydatin, trimebutine and honokiol trigger neuronal migration. In contrast, the mimetics crotamiton and duloxetine did not affect neuronal migration, thus limiting their use in increasing neuronal migration, leaving open the question of whether this is a desired or not desired feature in the adult.

Preoperative characteristics are associated with increased likelihood of low early postoperative mobility after adult spinal deformity surgery.

BACKGROUND CONTEXT: Low early postoperative mobility (LEPOM) has been shown to be associated with increased length of hospital stay, complication rates, and likelihood of nonhome discharge. However, few studies have examined preoperative characteristics associated with LEPOM in adult spinal deformity (ASD) patients. PURPOSE: To investigate which preoperative patient characteristics may be associated with LEPOM after ASD surgery. DESIGN: Retrospective review. PATIENT SAMPLE: Included were 86 ASD patients with fusion of ≥5 levels for whom immediate-postoperative AM-PAC Basic Mobility Inpatient Short Form (6-Clicks) scores had been obtained. OUTCOME MEASURES: The primary outcome of this study was the likelihood of LEPOM, defined as an AM-PAC score ≤15, which is associated with inability to stand for more than 1 minute. METHODS: Significant cutoffs for preoperative characteristics associated with LEPOM were determined via threshold linear regression. Multivariable logistic regression was used to assess the impact of preoperative characteristics on the likelihood of LEPOM. RESULTS: LEPOM was recorded in 38 patients (44.2%). Threshold regression identified the following cutoffs to be associated with LEPOM: preoperative Patient Reported Outcomes Measurement Information System (PROMIS) scores of ≥68 for Pain, <28.3 for Physical Function, and ≥63.4 for Anxiety; preoperative Oswestry disability index (ODI) score of ≥60; and body mass index (BMI) of ≥35.2. On multivariate analysis, preoperative PROMIS scores of ≥68 for Pain (odds ratio [OR] 5.3, confidence interval [CI] 1.2-22.8, p=.03), <28.3 for Physical Function (OR 10.1, CI 1.8-58.2, p=.01), and ≥63.4 for Anxiety (OR 4.7, CI 1.1-20.8, p=.04); preoperative ODI score ≥60 (OR 38.8, CI 4.0-373.6, p=.002); BMI ≥35.2 (OR 14.2, CI 1.3-160.0, p=.03), and male sex (OR 5.4, CI 1.2-23.7, p=.03) were associated with increased odds of LEPOM. CONCLUSIONS: Preoperative PROMIS Pain, Physical Function, and Anxiety scores; ODI score; BMI; and male sex were associated with LEPOM. Several of these characteristics are modifiable risk factors and thus may be candidates for optimization before surgery. LEVEL OF EVIDENCE: III.

Variation in Commercial Insurance Type Impacts Access to Cervical Spine Surgery.

INTRODUCTION: Prior literature has demonstrated that disparities exist in health care access and outcomes by insurance status, and patients with commercial plans fare better than those with Medicaid. However, variation may exist within commercial plans, which may impact care access. The purpose of our study was to determine the association between commercial health insurance plan type and access/time to surgery among patients with degenerative cervical conditions. METHODS: The MarketScan database (IBM Watson Health, Ann Arbor, MI) was utilized to identify the first instance of International Classification of Diseases-10-CM diagnosis codes for cervical myelopathy and radiculopathy. Patients 65 years old or below enrolled from 2015 to 2020 with a minimum of two years of continuous enrollment were included. Surgery for myelopathy included anterior cervical discectomy and fusion (ACDF), posterior cervical laminectomy and fusion, and laminoplasty, whereas surgery for radiculopathy included ACDF, cervical disk arthroplasty, and foraminotomy. The time between first diagnosis and surgery was determined. Insurance plan type was categorized as noncapitated (NC), non-high-deductible health plan, Health Management Organization-type partially or fully capitated plans, or high-deductible health plans (HDHP). Proportional hazards regression was utilized to compare time-to-incidence of surgery by plan type, adjusting for age, and sex. RESULTS: In total, 55,954 patients with cervical myelopathy and 705,117 patients with cervical radiculopathy were included. Mean follow-up was 537 and 657 days for myelopathy and radiculopathy, respectively. At two years postdiagnosis, 22.6% of myelopathy and 5.6% of radiculopathy patients were managed surgically. ACDF was the most common surgery for both myelopathy (85.7% of surgically managed patients) and radiculopathy (80.6%). The mean time to surgery for myelopathy was 101 days, and 196 days for radiculopathy. The most common plan type was NC for both myelopathy (81.5%, n=44,832) and radiculopathy (80.6%, n=559,109). Time-to-occurrence of surgery was significantly higher among both myelopathy and radiculopathy patients with capitated plans and HDHP versus NC plans, but the impact was significantly greater among those with radiculopathy than myelopathy (all P <0.05). CONCLUSIONS: Insurance plan structure has a significant impact on incidence of and on time-to-occurrence of surgery for patients with cervical degenerative conditions. Patients with HDHP plans may experience higher costs, potentially limiting access to care.

Fat Embolism Syndrome and in-Hospital Mortality Rates According to Patient Age: A Large Nationwide Retrospective Study.

Introduction: Fat embolism syndrome (FES) is a rare life-threatening condition that can develop after traumatic orthopedic injuries. Controversy remains concerning the epidemiology in the elderly population. Therefore, this study aims to report FES related to in-hospital mortality stratified by age. Methods: A retrospective trauma cohort study was conducted using data from the National Trauma Data Bank (NTDB) from 2007 to 2014. All FES cases were included in the study with the diagnosis of FES (ICD9 958.1). Death on arrival cases were excluded. Patients were stratified by age cohort: less than 40 (G1), 40-64 (G2), and greater than 65 (G3) years of age. The primary outcome evaluated was in-hospital mortality. Multivariable regression models were performed to adjust for potential confounders. Results: Between 2007 and 2014, 451 people from a total of 5,836,499 trauma patients in the NTDB met the inclusion criteria. The incidence rate was 8 out of 100,000. The inpatient mortality rate was 11.8% for all subjects with the highest mortality rate of 17.6% in patients over 65. Multivariable analyses demonstrated that age greater than 65 years was an independent predictor of mortality (aOR 24.16, 95% CI 3.73, 156.59, p=0.001), despite higher incidence and injury severity of FES among patients less than 40. No significant association with length of hospital stay, length of intensive unit care, or length of ventilation use was found between the groups. Subgroup analysis of the elderly population also showed a higher mortality rate for FES in femoral neck fracture patients (18%) than other femoral fractures (14%). Conclusion: In this retrospective cohort analysis, old age (≥ 65 years) was found to be an independent risk factor for in-hospital mortality among fat embolism syndrome patients. Elderly patients specifically with femoral neck fractures should be monitored for the development of FES.

Deep Learning for Radiographic Measurement of Femoral Component Subsidence Following Total Hip Arthroplasty.

Femoral component subsidence following total hip arthroplasty (THA) is a worrisome radiographic finding. This study developed and evaluated a deep learning tool to automatically quantify femoral component subsidence between two serial anteroposterior (AP) hip radiographs. The authors' institutional arthroplasty registry was used to retrospectively identify patients who underwent primary THA from 2000 to 2020. A deep learning dynamic U-Net model was trained to automatically segment femur, implant, and magnification markers on a dataset of 500 randomly selected AP hip radiographs from 386 patients with polished tapered cemented femoral stems. An image processing algorithm was then developed to measure subsidence by automatically annotating reference points on the femur and implant, calibrating that with respect to magnification markers. Algorithm and manual subsidence measurements by two independent orthopedic surgeon reviewers in 135 randomly selected patients were compared. The mean, median, and SD of measurement discrepancy between the automatic and manual measurements were 0.6, 0.3, and 0.7 mm, respectively, and did not demonstrate a systematic tendency between human and machine. Automatic and manual measurements were strongly correlated and showed no evidence of significant differences. In contrast to the manual approach, the deep learning tool needs no user input to perform subsidence measurements. Keywords: Total Hip Arthroplasty, Femoral Component Subsidence, Artificial Intelligence, Deep Learning, Semantic Segmentation, Hip, Joints Supplemental material is available for this article. © RSNA, 2022.

Do all outpatient spine surgeries cost the same? Comparison of economic outcomes data from a state-level database for outpatient lumbar decompression performed in an ambulatory surgery center or hospital outpatient setting.

OBJECTIVE: Spinal procedures are increasingly conducted as outpatient procedures, with a growing proportion conducted in ambulatory surgery centers (ASCs). To date, studies reporting outcomes and cost analyses for outpatient spinal procedures in the US have not distinguished the various outpatient settings from each other. In this study, the authors used a state-level administrative database to compare rates of overnight stays and nonroutine discharges as well as index admission charges and cumulative 7-, 30-, and 90-day charges for patients undergoing outpatient lumbar decompression in freestanding ASCs and hospital outpatient (HO) settings. METHODS: For this project, the authors used the Florida State Ambulatory Surgery Database (SASD), offered by the Healthcare Cost and Utilization Project (HCUP), for the years 2013 and 2014. Patients undergoing outpatient lumbar decompression for degenerative diseases were identified using CPT (Current Procedural Terminology) and ICD-9 codes. Outcomes of interest included rates of overnight stays, rate of nonroutine discharges, index admission charges, and subsequent admission cumulative charges at 7, 30, and 90 days. Multivariable analysis was performed to assess the impact of outpatient type on index admission charges. Marginal effect analysis was employed to study the difference in predicted dollar margins between ASCs and HOs for each insurance type. RESULTS: A total of 25,486 patients were identified; of these, 7067 patients (27.7%) underwent lumbar decompression in a freestanding ASC and 18,419 (72.3%) in an HO. No patient in the ASC group required an overnight stay compared to 9.2% (n = 1691) in the HO group (p < 0.001). No clinically significant difference in the rate of nonroutine discharge was observed between the two groups. The mean index admission charge for the ASC group was found to be significantly higher than that for the HO group ($35,017.28 ± $14,335.60 vs $33,881.50 ± $15,023.70; p < 0.001). Patients in ASCs were also found to have higher mean 7-day (p < 0.001), 30-day (p < 0.001), and 90-day (p = 0.001) readmission charges. ASC procedures were associated with increased charges compared to HO procedures for patients on Medicare or Medicaid (mean index admission charge increase $4049.27, 95% CI $2577.87-$5520.67, p < 0.001) and for patients on private insurance ($4775.72, 95% CI $4171.06-$5380.38, p < 0.001). For patients on self-pay or no charge, a lumbar decompression procedure at an ASC was associated with a decrease in index admission charge of -$10,995.38 (95% CI -$12124.76 to -$9866.01, p < 0.001) compared to a lumbar decompression procedure at an HO. CONCLUSIONS: These "real-world" results from an all-payer statewide database indicate that for outpatient spine surgery, ASCs may be associated with higher index admission and subsequent 7-, 30-, and 90-day charges. Given that ASCs are touted to have lower overall costs for patients and better profit margins for physicians, these analyses warrant further investigation into whether this cost benefit is applicable to outpatient spine procedures.

The analgesic effect of intravenous lidocaine versus intrawound or epidural bupivacaine for postoperative opioid reduction in spine surgery: A systematic review and meta-analysis.

BACKGROUND: Pain management following spine surgery remains a challenge. The significant use of opioids may lead to opioid-related adverse events. These complications can increase perioperative morbidity and rapidly expend health care resources by developing chronic pain. Although intraoperative pain control for surgery has been studied in the literature, a thorough assessment of the effect in spine surgery is rarely reported. The objective of the present study was to examine the outcomes of intraoperative intravenous lidocaine and intrawound or epidural bupivacaine use in spine surgery. METHODS: An electronic literature search was conducted for studies on the use of lidocaine and bupivacaine in spine surgery for all years available. Only articles in English language were included. Postoperative opioid consumption, VAS score, nausea/vomiting, and length of hospital stay comprised the outcomes of interest. Pooled descriptive statistics with Risk Ratios (RR), Mean Differences (MD) and 95 % confidence interval were used to synthesize the outcomes for each medication. RESULTS: A total of 10 studies (n = 579) were included in the analysis. Comparison of the opioid consumption revealed a significant mean difference between lidocaine and bupivacaine (MD: -12.25, and MD: -0.4, respectively, p = 0.01), favoring lidocaine. With regard to postoperative VAS, the pooled effect of both groups decreased postoperative pain (MD: -0.61 (95 % CI: -1.14, -0.08)), with a more significant effect in the lidocaine group (MD: -0.84, (95 % CI: -1.21, -0.48)). There was no significant effect in length of stay, and postoperative nausea/vomiting. CONCLUSIONS: The results of the present meta-analysis indicate that lidocaine and bupivacaine use may decrease postoperative pain and opioid consumption. Lidocaine had a stronger effect on the reduction of opioid consumption compared to bupivacaine.

Correlations Between COVID-19 Cases and Google Trends Data in the United States: A State-by-State Analysis.

OBJECTIVE: To evaluate whether a digital surveillance model using Google Trends is feasible for obtaining accurate data on coronavirus disease 2019 and whether accurate predictions can be made regarding new cases. METHODS: Data on total and daily new cases in each US state were collected from January 22, 2020, to April 6, 2020. Information regarding 10 keywords was collected from Google Trends, and correlation analyses were performed for individual states as well as for the United States overall. RESULTS: Among the 10 keywords analyzed from Google Trends, face mask, Lysol, and COVID stimulus check had the strongest correlations when looking at the United States as a whole, with R values of 0.88, 0.82, and 0.79, respectively. Lag and lead Pearson correlations were assessed for every state and all 10 keywords from 16 days before the first case in each state to 16 days after the first case. Strong correlations were seen up to 16 days prior to the first reported cases in some states. CONCLUSION: This study documents the feasibility of syndromic surveillance of internet search terms to monitor new infectious diseases such as coronavirus disease 2019. This information could enable better preparation and planning of health care systems.

Risk Factors for Unplanned Readmissions Following Anterior Cervical Discectomy and Fusion and Posterior Lumbar Fusion Procedures: Comparison of Two National Databases.

BACKGROUND: The National Surgical Quality Improvement Program (NSQIP) and National Readmission Database (NRD) are 2 widely used databases that provide valuable information regarding the quality of health care. However, the 2 differ in sampling methodology, which may result in conflicting findings when used for research studies. The objective of this study is to evaluate the differences regarding predictors of 30-day readmissions after anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF). METHODS: In this case-control study, NSQIP and NRD were queried for patients undergoing elective ACDF and PLF between 2014 and 2015. The outcome of interest was 30-day readmissions following ACDF and PLF, which were unplanned and related to the index procedure. Subsequently, univariable and multivariable analyses were conducted to determine the predictors of 30-day readmissions using both databases. RESULTS: For ACDF procedures, diagnosis, outpatient status, American Society of Anesthesiologists class, and length of hospital stay were found to be significant predictors of 30-day readmissions in NSQIP, whereas only age and hypertension were significant in NRD. Among patients undergoing PLF procedures, body mass index, functional status, smoking, steroid use, diabetes, dyspnea, dialysis, emergency, discharge to rehab facility, and length of hospital stay were found to be significant predictors of 30-day readmissions in NSQIP, whereas only alcohol abuse and obesity were significant predictors in NRD. CONCLUSIONS: Two databases differed in terms of significant predictors of 30-day readmissions following ACDF and PLF. This difference may emphasize the differences in the sampling methodology. Further analyses, potentially with an institutional validation, are needed to draw conclusions regarding the accuracy of the 2 databases for predictive analytics.

Institutional databases may underestimate the risk factors for 30-day unplanned readmissions compared to national databases.

OBJECTIVE: The National Surgical Quality Improvement Program (NSQIP) and National Readmissions Database (NRD) are two widely used databases for research studies. However, they may not provide generalizable information in regard to individual institutions. Therefore, the objective of the present study was to evaluate 30-day readmissions following anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF) procedures by using these two national databases and an institutional cohort. METHODS: The NSQIP and NRD were queried for patients undergoing elective ACDF and PLF, with the addition of an institutional cohort. The outcome of interest was 30-day readmissions following ACDF and PLF, which were unplanned and related to the index procedure. Subsequently, univariable and multivariable analyses were conducted to determine the predictors of 30-day readmissions by using both databases and the institutional cohort. RESULTS: Among all identified risk factors, only hypertension was found to be a common risk factor between NRD and the institutional cohort following ACDF. NSQIP and the institutional cohort both showed length of hospital stay to be a significant predictor for 30-day related readmission following PLF. There were no overlapping variables among all 3 cohorts for either ACDF or PLF. Additionally, the national databases identified a greater number of risk factors for 30-day related readmissions than did the institutional cohort for both procedures. CONCLUSIONS: Overall, significant differences were seen among all 3 cohorts with regard to top predictors of 30-day unplanned readmissions following ACDF and PLF. The higher quantity of significant predictors found in the national databases may suggest that looking at single-institution series for such analyses may result in underestimation of important variables affecting patient outcomes, and that big data may be helpful in addressing this concern.

Assessing the Effects of Publication Bias on Reported Outcomes of Cervical Disc Replacement and Anterior Cervical Discectomy and Fusion: A Meta-Epidemiologic Study.

BACKGROUND: There have been several clinical trials as well as observational studies that have compared the outcomes of different cervical disc replacement (CDR) devices with anterior cervical disc replacement and fusion (ACDF). Although the results of these studies have provided sufficient evidence for the safety of CDR, there is still a lack of consensus in terms of longer-term outcomes, with studies providing equivocal results for the 2 procedures. In the current study, we used a novel methodology, a meta-epidemiologic study, to investigate the impact of study characteristics on the observed effects in the literature on CDR and ACDF. METHODS: Data were abstracted from available meta-analyses regarding author, study author, year, intervention events, control events, and sample size, as well as year and geographic location of each study within the meta-analyses. We grouped the studies based on median year of publication as well as the region of the submitting author(s). Odds ratios, 95% confidence intervals (CIs), and standard errors of individual studies were calculated based on the number of events and sample size for each arm (ACDF or CDR). Further, results of outcomes from individual studies were pooled and a meta-analysis was conducted. Ratio of odds ratio (ROR) was used to assess the impact of each of these factors on estimates of the study for CDR versus ACDF. RESULTS: A total of 13 meta-analyses were analyzed after exclusions. Using the results from 10 meta-analyses, we found that studies published before 2012 reported significantly lower odds of a reoperation after CDR (vs. ACDF), compared with studies published after 2012 (ROR, 0.51; 95% CI, 0.38-0.67; P < 0.001). We did not observe a significant impact of study year on difference in estimates between CDR and ACDF for adjacent segment disease (ROR, 0.99; 95% CI, 0.64-1.55; P = 0.465). The region of submitting author was also found to have no impact on results of published studies. CONCLUSIONS: These results indicate that there may be a publication bias regarding the year of publication, with earlier studies reporting lower reoperation rates for CDR compared with ACDF.

Assessing the Difference in Clinical and Radiologic Outcomes Between Expandable Cage and Nonexpandable Cage Among Patients Undergoing Minimally Invasive Transforaminal Interbody Fusion: A Systematic Review and Meta-Analysis.

BACKGROUND: Minimally invasive transforaminal interbody fusion (MIS-TLIF) has been shown to have excellent outcomes for surgical management of degenerative disc disease. However, the challenge is in addressing coronal imbalance and restoring lumbar lordosis and sagittal alignment. Use of expandable cages in MIS-TLIF has been hypothesized to circumvent this disadvantage. An indirect meta-analysis of the evidence is presented comparing outcomes from expandable cages with those from nonexpandable cages, in patients undergoing MIS-TLIF. METHODS: PRISMA guidelines were used to conduct a systematic review and meta-analysis to compare the clinical and radiologic outcomes of expandable cages and nonexpandable cages in patients undergoing MIS-TLIF. RESULTS: Twelve studies (706 patients) were included in the meta-analysis. The mean increase in disc height was found to be significantly greater for the nonexpandable cages group than for the expandable cages group (1.33 mm; 95% confidence interval [CI], 1.28-1.38 vs. 1.14 mm,; 95% CI, 1.06-1.23; P < 0.001). No significant difference was found regarding change in lumbar lordosis at last follow-up between the 2 groups (P = 0.34). The mean change in segmental lordosis was found to be significantly higher for the expandable cage group (5.04°, 95% CI, 3.89-6.20 vs. 2.08°, 95% CI, 1.93-2.22; P < 0.001). We did not detect any significant difference in fusion rate (P = 0.33), subsidence rate (P = 0.41) or in reoperations (P = 0.56) at last follow-up between the 2 groups. CONCLUSIONS: Our results indicate that there may not be a significant difference in clinical and radiologic parameters between expandable cages and nonexpandable cages among patients undergoing MIS-TLIF, and it is unclear if the higher cost of the expandable cages is justified.