The fragility index and reverse fragility index of FDA investigational device exemption trials in spinal fusion surgery: a systematic review.

PURPOSE: FDA investigational device exemption (IDE) studies are considered a gold standard of assessing safety and efficacy of novel devices through RCTs. The fragility index (FI) has emerged as a means to assess robustness of statistically significant study results and inversely, the reverse fragility index (RFI) for non-significant differences. Previous authors have defined results as fragile if loss to follow up is greater than the FI or RFI. The aim of this study was to assess the FI, RFI, and robustness of data supplied by IDE studies in spinal surgery. METHODS: This was a systematic review of the literature. Inclusion criteria included randomized controlled trials with dichotomous outcome measures conducted under IDE guidelines between 2000 and 2023. FI and RFI were calculated through successively changing events to non-events until the outcome changed to non-significance or significance, respectively. The fragility quotient (FQ) and reverse fragility quotient (RFQ) were calculated by dividing the FI and RFI, respectively, by the sample size. RESULTS: Thirty-two studies met inclusion criteria with a total of 40 unique outcome measures; 240 outcomes were analyzed. Twenty-six studies reported 96 statistically significant results. The median FI was 6 (IQR: 3-9.25), and patients lost to follow up was greater than the FI in 99.0% (95/96) of results. The average FQ was 0.027. Thirty studies reported 144 statistically insignificant results and a median RFI of 6 (IQR: 4-8). The average RFQ extrapolated was 0.021, and loss to follow up was greater than the RFI in 98.6% (142/144) of results. CONCLUSIONS: IDE studies in spine surgery are surprisingly fragile given their reputations, large sample sizes, and intent to establish safety in investigational devices. This study found a median FI and RFI of 6. The number of patients lost to follow-up was greater than FIand RFI in 98.8% (237/240) of reported outcomes. FQ and RFQ tell us that changes of two to three patients per hundred can flip the significance of reported outcomes. This is an important reminder of the limitations of RCTs. Analysis of fragility in future studies may help clarify the strength of the relationship between reported data and their conclusions.

Academic and Demographic Characteristics of Pediatric Orthopaedic Division Chiefs in the United States.

INTRODUCTION: Division Chiefs (DCs) and department leadership play an integral role within the service. The goal of this study is to assess the demographics and scholarly work of the leadership in pediatric orthopaedics services across the United States and comment on the role of diversity within leadership positions. METHODS: Academic medical centers and pediatric hospitals were identified using the Electronic Residency Application Service website, the Pediatric Orthopaedic Society of North America website, and the Children's Hospital Association website. Leadership was identified using the hospitals' respective websites where data such as sex, race/ethnicity, fellowship institution, time since graduating fellowship, and academic rank were collected. Scopus database was used to determine h-indices and PubMed was used to determine the number of publications. RESULTS: Of 196 academic centers and 223 pediatric hospitals identified, 98 had a designated DC of the pediatric orthopaedics division. The majority of the DCs were male (85.7%), and leadership positions at hospitals with academic affiliations had a higher proportion of female DCs than nonacademic centers ( P =0.0317). DCs were mostly white (83.7%), followed by Asian (12.2%), and African American (2.0%). The average time since fellowship was 21.1 years and the average h-index was 15.7. The average age of the DCs was 56.8 years old. Of those in academic settings, 48.5% held the rank of professor. The fellowship programs that trained the most DCs were Boston Children's Hospital (16.3%) and Texas Scottish Rite for Children (14.3%). DISCUSSION: There is a paucity of available research on leadership characteristics in pediatric orthopaedic surgery. While progress has been made, there is still a lack of diversity that exists among leadership in pediatric orthopaedics, both within the academic setting as well as the private sector. The position of DC is held predominately by white males with a rank of either professor or no academic association. Intentional efforts are needed to continue to increase diversity in leadership positions within pediatric orthopaedic programs in the United States. LEVEL OF EVIDENCE: IV.

Spine Surgeon Assessments of Patient Psychological Distress are Inaccurate and Bias Treatment Recommendations.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: This study determined (1) the surgeon accuracy of psychological assessment in patients in spine clinic, (2) the impact of psychological distress on surgical recommendation, and (3) the correlation between patient-reported disability and psychological distress. SUMMARY OF BACKGROUND DATA: Psychological distress is common among patients presenting for spine surgery. Surgeon estimations of patients' distress may influence treatment recommendations, but little is known as to whether these assessments accurately mirror patient-perceived psychological distress. MATERIALS AND METHODS: A sample of new patients was recruited from an academic spine center. Prior to their initial consultation, patients completed the Modified Somatic Perception Questionnaire and Zung Depression Index to assess mental and physical manifestations of distress, which generated a Distress and Risk Assessment Method (DRAM) score of N (normal), R (at risk), or D (distressed). The Oswestry Disability Index and Neck Disability Index scores were also collected. Surgeons provided their estimates of the DRAM score after the visit and indicated their surgery recommendation. RESULTS: Of 296 patients, 40.5% reported some level of psychological distress (DRAM=R) and 15.9% had a high level of distress (DRAM=D). All three surgeons' ability to accurately assess the participant DRAM score was poor, with an overall kappa of 0.13 (0.08-0.18), biased toward underestimating the patient's true level of psychological distress. Patients rated as normal (N) by the surgeon were 3.78 times more likely to be recommended for surgery compared to those assessed as distressed (D) ( P =0.007). Patients with higher DRAM scores had higher Oswestry Disability Index ( P =0.008) and Neck Disability Index ( P =0.005) scores compared to those with lower DRAM scores. CONCLUSIONS: Spine surgeons have limited ability to detect psychological profiles in patients, with a tendency to underestimate levels of distress. The finding that these inaccurate assessments influence surgical recommendations underscores the importance of limiting surgeon bias in the decision-making process. LEVEL OF EVIDENCE: Diagnostic Level 2.

A Modified Method of Triggered Electromyography Monitoring in Minimally Invasive Spine Surgery: Comparison to Conventional Techniques and Correlation with Body Mass Index.

PURPOSE: Conventional triggered electromyography (EMG) in percutaneous pedicle screw (PPS) systems may be unreliable due to the interaction between the insertion apparatus and patient's soft tissue. Our aim was 1) to describe a modified technique of triggered EMG monitoring using insulated Kirschner wire (K-wires), 2) to compare EMG potentials with conventional techniques, and 3) to demonstrate the relationship between patient body mass index (BMI) and triggered EMG potentials. METHODS: This was a prospective cross-sectional study of 50 patients undergoing minimally invasive PPS placement. Triggered EMG measurements using K-wires before and after insulation were compared. The difference between EMG measurements before and after insulation was correlated with patient BMI. RESULTS: A total of 50 patients, 22 females and 28 males, underwent triggered EMG testing using K-wires prior to final PPS placement in the thoracic and lumbosacral spine for a total of 472 triggered EMG measurements. When compared to standard triggered EMG monitoring, insulated triggered EMG monitoring demonstrated an average 55.4% decrease in EMG values (P < 0.001). Increasing BMI correlated to increasing % decrease in EMG values (r-coefficient, 0.376; P < 0.01). CONCLUSIONS: We describe a cost-effective, efficient, and reliable technique for triggered EMG during PPS placement which may help ensure accurate screw placement and minimize potentially devastating complications.

Predictors of Medical Malpractice Outcomes After Spine Surgery: A Comprehensive Analysis From 2010 to 2019.

STUDY DESIGN: Retrospective review of spine surgery malpractice cases. OBJECTIVES: The aim was to compare medical malpractice outcomes among different types of spine surgery and identify predictors of litigation outcomes. SUMMARY OF BACKGROUND DATA: Spine surgery is highly litigious in the United States with data suggesting favorable outcomes for defendant surgeons. However, factor specific data and explanations for plaintiff verdicts are lacking. METHODS: Westlaw legal database was queried for spine surgery malpractice outcomes from 2010 to 2019. Clinical data, reasons for litigation, and legal outcomes were tabulated. Statistical analysis was performed to identify factors associated with litigation outcomes. RESULTS: A total of 257 cases were identified for inclusion. There were 98 noninstrumented and 148 instrumented cases; 110 single-level and 99 multilevel; 83 decompressions, 95 decompression and fusions, and 47 fusion only. In all, 182 (71%) resulted in a defendant verdict, 44 (17%) plaintiff verdict, and 31 (12%) settlement. Plaintiff verdicts resulted in payouts of $2.03 million, while settlements resulted in $1.11 million (P=0.34). Common reasons for litigation were intraoperative error, hardware complication, and improper postoperative management. Cases were more likely to result for the plaintiff if postoperative cauda equina syndrome (55% vs. 26%, P<0.01), a surgical site infection (46% vs. 27%, P=0.03), or other catastrophic injury (40% vs. 26%, P=0.03) occurred. Higher monetary awards were associated with multi versus single-level (median: $2.61 vs. $0.92 million, P=0.01), improper postoperative management cited (median: $2.29 vs. $1.12 million, P=0.04), and permanent neurological deficits ($2.29 vs. $0.78 million, P<0.01). Plaintiff payouts were more likely if defendant specialty was neurosurgery versus orthopedic surgery (33% vs. 18%, P=0.01). CONCLUSIONS: Spine surgery is a litigious field with multiple factors associated with outcomes. Efforts to reduce intraoperative errors and complications may improve patient care and decrease the risk of litigation.

Progress not panacea: vancomycin powder efficacy and dose evaluated in an in vivo mouse model of spine implant infection.

BACKGROUND: Intrawound vancomycin powder (VP) has been rapidly adopted in spine surgery with apparent benefit demonstrated in limited, retrospective studies. Randomized trials, basic science, and dose response studies are scarce. PURPOSE: This study aims to test the efficacy and dose effect of VP over an extended time course within a randomized, controlled in vivo animal experiment. STUDY DESIGN/SETTING: Randomized controlled experiment utilizing a mouse model of spine implant infection with treatment groups receiving vancomycin powder following bacterial inoculation. METHODS: Utilizing a mouse model of spine implant infection with bioluminescent Staphylococcus aureus, 24 mice were randomized into 3 groups: 10 infected mice with VP treatment (+VP), 10 infected mice without VP treatment (No-VP), and 4 sterile controls (SC). Four milligrams of VP (mouse equivalent of 1 g in a human) were administered before wound closure. Bioluminescence imaging was performed over 5 weeks to quantify bacterial burden. Electron microscopy (EM), bacterial colonization assays (Live/Dead) staining, and colony forming units (CFU) analyses were completed. A second dosing experiment was completed with 34 mice randomized into 4 groups: control, 2 mg, 4 mg, and 8 mg groups. RESULTS: The (+VP) treatment group exhibited significantly lower bacterial loads compared to the control (No-VP) group, (p<.001). CFU analysis at the conclusion of the experiment revealed 20% of mice in the +VP group and 67% of mice in the No-VP group had persistent infections, and the (+VP) treatment group had significantly less mean number of CFUs (p<.03). EM and Live/Dead staining revealed florid biofilm formation in the No-VP group. Bioluminescence was suppressed in all VP doses tested compared with sterile controls (p<.001). CFU analysis revealed a 40%, 10%, and 20% persistent infection rate in the 2 mg, 4 mg, and 8 mg dose groups, respectively. CFU counts across dosing groups were not statistically different (p=.56). CONCLUSIONS: Vancomycin powder provided an overall infection prevention benefit but failed to eradicate infection in all mice. Furthermore, the dose when halved also demonstrated an overall protective benefit, albeit at a lower rate. CLINICAL SIGNIFICANCE: Vancomycin powder is efficacious but should not be viewed as a panacea for perioperative infection prevention. Dose alterations can be considered, especially in patients with kidney disease or at high risk for seroma.

A Comparison of Defense and Plaintiff Expert Witnesses in Orthopaedic Surgery Malpractice Litigation.

BACKGROUND: According to the American Academy of Orthopaedic Surgeons (AAOS) Standards of Professionalism, the responsible testimony of expert witnesses in orthopaedic surgery malpractice lawsuits is important to the public interest. However, these expert witnesses are recruited and compensated without established standards, and their testimony can potentially sway court opinion, with substantial consequences. The objective of this study was to characterize defense and plaintiff expert orthopaedic surgeon witnesses in orthopaedic surgery malpractice litigation. METHODS: Utilizing the WestlawNext legal database, defense and plaintiff expert witnesses involved in orthopaedic surgery malpractice lawsuits from 2013 to 2017 were identified. Each witness's subspecialty, mean years of experience, involvement in academic or private practice, fellowship training, and scholarly impact, as measured by the Hirsch index (h-index), were determined through a query of professional profiles, the Scopus database, and a PubMed search. Statistical comparisons were made for each parameter among defense and plaintiff expert witnesses. RESULTS: Between 2013 and 2017, 306 expert medical witnesses for orthopaedic cases were identified; 174 (56.9%) testified on behalf of the plaintiff, and 132 (43.1%) testified on behalf of the defense. Orthopaedic surgeons who identified themselves as general orthopaedists comprised the largest share of expert witnesses on both the plaintiff (n = 61) and defense (n = 25) sides. The plaintiff witnesses averaged 36 years of experience versus 31 years for the defense witnesses (p < 0.001); 26% of the plaintiff witnesses held an academic position versus 43% of the defense witnesses (p = 0.013). Defense witnesses exhibited a higher proportion of fellowship training in comparison to plaintiff expert witnesses (80.5% versus 64.5%, respectively, p = 0.003). The h-index for the plaintiff group was 6.6 versus 9.1 for the defense group (p = 0.04). Two witnesses testified for both the plaintiff and defense sides. CONCLUSIONS: Defense expert witnesses held higher rates of academic appointments and exhibited greater scholarly impact than their plaintiff counterparts, with both sides averaging >30 years of experience. These data collectively show that there are differences in characteristics between plaintiff and defense witnesses. Additional study is needed to illuminate the etiology of these differences.