The fragility of statistical findings in the reverse total shoulder arthroplasty literature: a systematic review of randomized controlled trials.

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) has seen increasing utilization as an effective intervention for a wide variety of shoulder pathologies. The scope and indications for growth are often driven by findings from randomized controlled trials (RCTs) guiding surgical decision-making for RTSA. In this study, we utilized the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ) to assess the robustness of outcomes reported in RCTs in the RTSA literature. METHODS: PubMed, Embase, and MEDLINE were queried for RCTs (Jan. 1, 2010-Mar. 31, 2023) in the RTSA literature reporting dichotomous outcomes. The FI and rFI were defined as the number of outcome reversals required to alter statistical significance for significant and nonsignificant outcomes, respectively. The FQ was determined by dividing the FI by the sample size of each study. Subgroup analysis was performed based on outcome category. RESULTS: One hundred seventy-six RCTs were screened with 18 studies included. The median FI across 59 total outcomes was 4 (interquartile range [IQR]: 3-5) with an associated FQ of 0.051 (IQR: 0.029-0.065). Thirteen outcomes were statistically significant with a median FI of 3 (IQR: 1-4) and FQ of 0.033 (IQR: 0.012-0.066). Forty-six outcomes were nonsignificant with a median rFI of 4 (IQR: 3-5) and FQ of 0.055 (IQR: 0.032-0.065). The most fragile outcome category was revision/reoperations with a median FI of 2.50 (IQR: 1.00-3.25), followed by clinical score/outcome (median FI: 3.00), complications (median FI: 4.00), "other" (median FI: 4.00), and radiographic findings (median FI: 5.00). Notably, the number of patients lost to follow-up was greater than or equal to the FI for 59% of outcomes. CONCLUSION: The statistical findings in RTSA RCTs are fragile and should be interpreted with caution. Reversal of only a few outcomes, or maintaining postoperative follow-up, may be sufficient to alter significance of study findings. We recommend standardized reporting of P values with FI and FQ metrics to allow clinicians to effectively assess the robustness of study findings.

Is the Child Opportunity Index a Factor in Surgical Outcomes for Adolescent Idiopathic Scoliosis?

BACKGROUND: Low socioeconomic status (SES) has been previously associated with delays in orthopaedic care. However, it is unclear how SES impacts patients with adolescent idiopathic scoliosis (AIS), particularly regarding preoperative major coronal curve angle or surgical outcomes. Utilizing the Child Opportunity Index (COI)-an address-driven measure of pediatric education, health/environment, and SES-we investigated whether COI is associated with differences in preoperative scoliosis magnitude, age at surgery, and AIS surgical outcomes. METHODS: Consecutive patients with AIS surgically treated at a single center from 2011 to 2017 were reviewed. COI was calculated by inserting a patient's home address into the nationally available COI database to derive a COI value. COI is scored from 0.0 to 100.0 (0.0 is lowest, 100.0 is highest). Specifically, COI is categorized as very low (<20.0), low (20 to 39.9), moderate (40 to 59.9), high (60 to 79.9), and very high (≥80). Those without addresses were excluded. Patients without proper radiographs to assess curve correction were also excluded. A COI threshold of 60.0 was used to separate patients into a low (<60.0) or high COI ( ) group based on published COI guidelines. Outcomes, including preoperative curve magnitude, age at surgery, percentage curve correction, operative time (OT), intraoperative estimated blood loss per level fused, length of stay, and complications, were compared across groups. Pearson correlation analysis was used to assess correlations between COI and preoperative curve magnitude, as well as age. RESULTS: Four hundred four patients were included in the study, and 263 had 2-year follow-up data. Patients were an average age of 14.9 years old (range: 11.2 to 19.8), had a median COI of 76 (range: 4 to 100), and had a mean preoperative major curve angle of 59 degrees (range: 36 to 93). COI was significantly higher for white patients compared with non-white (80.0 vs 40.0, P < 0.001), and higher for non-Hispanic individuals (79.0 vs 15.0, P < 0.001). Patients with Low COI were associated with a lower OT per level fused ( P = 0.003) and decreased postoperative complication risk ( P = 0.02). COI was not associated with preoperative major coronal curve angle, age at surgery, or any other surgical outcomes. CONCLUSION: COI was significantly lower for non-white patients and those of Hispanic ethnicity. Patients from low COI backgrounds achieved similar surgical results as those from high COI addresses and had a decreased OT per level fused and complication incidence, though the clinical significance of these differences is unknown. Future prospective studies are needed to determine whether these findings are reproducible across other states and health systems. LEVEL OF EVIDENCE: Level III-prognostic study.

Pedicle Screw Placement in Adolescent Idiopathic Scoliosis: A Comparison between Robotics Coupled with Navigation versus the Freehand Technique.

(1) Background: Robotics coupled with navigation (RAN) is a modern surgical platform shown to increase screw placement accuracy during pediatric scoliosis surgery. Our institution uses a technique which combines the RAN platform for apical pedicle screw placement and the freehand (FH) technique for terminal pedicle screw placement during scoliosis surgery (termed hybrid technique). We question if the complementary use of the RAN technology affects intraoperative outcomes, relative to the FH-only approach. (2) Methods: 60 adolescent idiopathic scoliosis (AIS) patients, ages 11−19 at surgery, who were operated on from 2019 through 2020 by a single surgeon, were retrospectively reviewed. Patients were separated by surgery type (hybrid RAN or FH), matched on demographic and surgical factors, and their intraoperative outcomes were compared statistically. (3) Results: Hybrid RAN patients had more screws placed (p = 0.01) and were of a higher BMI percentile (p = 0.005). Controlling for the number of screws placed, BMI%, and initial curve magnitude, there were no statistical differences in estimated blood loss per screw (p = 0.51), curve correction (p = 0.69), complications (p = 0.52), or fluoroscopy time (p = 0.88), between groups. However, operative time was two minutes longer per screw for hybrid RAN patients (p < 0.001). (4) Conclusions: Hybrid RAN surgeries took longer than FH, but yielded comparable effectiveness and safety as the FH technique during the initial RAN adoption phase.

Intraoperative Use of Robotics With Navigation for Pedicle Screw Placement in Treatment of Pediatric High-grade Spondylolisthesis: A Preliminary Report.

BACKGROUND: Accurate pedicle screw placement is critical to surgically correct pediatric high-grade spondylolisthesis (HGS). The recent advent of robotics coupled with computer-assisted navigation (RAN) may represent a novel option to improve surgical outcomes of HGS, secondary to enhanced pedicle screw placement safety. This series presents the HGS-RAN technique adopted by our site, describing its surgical outcomes and feasibility. METHODS: Consecutive patients with a diagnosis of HGS (Meyerding grade III to V), operated on using RAN from 2019 to 2020 at a single-center were reviewed. Demographics, screw accuracy, sagittal L5-S1 parameters, complications, and perioperative outcomes were described. All patients were treated with instrumentation, decompression, posterior lumbar interbody fusion, and reduction. Robotic time included anatomic registration to end of screw placement. Screw accuracy-defined as a screw placed safely within the planned intrapedicular trajectory-was characterized by the Gertzbein-Robbins system for patients with additional 3-dimensional imaging. RESULTS: Ten HGS patients, with an average age of 13.7 years old, were included in the series. All 62 screws were placed without neurological deficit or complication. Seven patients had additional 3-dimensional imaging to assess screw accuracy (42 of 62 screws). One hundred percent of screws were placed safely with no pedicle breaches (Gertzbein-Robbins-grade A). Thirty screws (48%) were placed through separate incisions that were percutaneous/transmuscular and 32 screws (52%) were inserted through the main incision. There were statistically significant improvements in L5 slippage (P=0.002) and lumbosacral angle (P=0.002), reflecting successful HGS correction. The total median operative time was 324 minutes with the robotic usage time consuming a median of 72 minutes. Median estimated blood loss was 150 mL, and length-of-stay was a median 3 days. CONCLUSIONS: This case-series demonstrates that RAN represents a viable option for HGS repair, indicated by high screw placement accuracy, safety, and L5-S1 slippage correction. Surgeons looking to adopt an emerging technique to enhance safety and correction of pediatric HGS should consider the RAN platform. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Utility of postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis.

PURPOSE: With advancements to blood management strategies, risk of perioperative transfusion following surgical treatment of adolescent idiopathic scoliosis (AIS) has diminished. We hypothesize that routine laboratory testing on postoperative-day 1 (POD1) and beyond is unnecessary. The purpose of this study is to determine necessity of POD1 labs, particularly hematocrit and hemoglobin levels, following surgical management of AIS. METHODS: We performed a retrospective cohort study of consecutive AIS patients aged 11-19 who underwent posterior spinal fusion (PSF) at a single institution. Univariable logistic regression was utilized to determine factors associated with hematocrit ≤ 22% on POD1 or a postoperative transfusion. Firth's penalized logistic regression was used for any separation in data. Youden's index was utilized to determine the optimal point on the ROC curve that maximizes both sensitivity and specificity. RESULTS: 527 patients qualified for this study. Among the eight total patients with POD1 hematocrit ≤ 22, none underwent transfusion. These patients had lower last intraoperative hematocrit levels compared to patients with POD1 hematocrit > 22% (24.1% vs 31.5%, p < 0.001), and these groups showed no difference in preoperative hematocrit levels (38.2% vs 39.8%, p = 0.11). Four patients underwent postoperative transfusion. Both preoperative hematocrit levels (34.0% vs 39.9%, p = 0.001) and last intraoperative hematocrit levels (25.1% vs 31.4%, p = 0.002) were lower compared to patients without transfusion. Intraoperative hematocrit < 26.2%, operative time of more than 35.8 min per level fused, or cell salvage > 241 cc were significant risk factors for postoperative transfusion. CONCLUSION: Transfusion after PSF for AIS is exceedingly rare. POD1 labs should be considered when last intraoperative hematocrit < 26%, operative time per level fused > 35 min, or cell salvage amount > 241 cc. Otherwise, unless symptomatic, patients do not benefit from postoperative laboratory screening.

Analysis of 5,070 consecutive pedicle screws placed utilizing robotically assisted surgical navigation in 334 patients by experienced pediatric spine deformity surgeons: surgical safety and early perioperative complications in pediatric posterior spinal fusion.

PURPOSE: This study evaluates the intraoperative and short-term complications associated with robotically assisted pedicle screw placement in pediatric posterior spinal fusion (PSF) from three surgeons at two different institutions. METHODS: We retrospectively reviewed 334 pediatric patients who underwent PSF with robotic-assisted navigation at 2 institutions over 3 years (2020-2022). Five thousand seventy robotically placed screws were evaluated. Data collection focused on intraoperative and early postoperative complications with minimum 30-day follow-up. Patients undergoing revision procedures were excluded. RESULTS: Intraoperative complications included 1 durotomy, 6 patients with neuromonitoring alerts not related to screw placement, and 62 screws (1.2%) with documented pedicle breaches, all of which were revised at time of surgery. By quartile, pedicle breaches statistically declined from first quartile to fourth quartile (1.8% vs. 0.56%, p < 0.05). No breach was associated with neuromonitoring changes or neurological sequelae. No spinal cord or vascular injuries occurred. Seventeen postoperative complications occurred in eleven (3.3%) of patients. There were five (1.5%) patients with unplanned return to the operating room. CONCLUSION: Robotically assisted pedicle screw placement was safely and reliably performed on pediatric spinal deformity by three surgeons across two centers, demonstrating an acceptable safety profile and low incidence of unplanned return to the operating room.

The Longitudinal Effects of Posterior Spinal Fusion with Derotation on Axial Deformity in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To characterize the change in angle of trunk rotation (ATR), axial vertebral rotation (AVR), and body surface rotation (BSR) in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with en-bloc derotation across multiple postoperative visits. SUMMARY OF BACKGROUND DATA: Previous research has documented ATR, AVR, and BSR correction for AIS patients after surgery. However, there is a lack of evidence on the sustainability of this correction over time. METHODS: This was a retrospective study from a single-center prospective surface topographic registry of patients with AIS, age 11-20 at time of surgery, who underwent PSF with en-bloc derotation. Patients with previous spine surgery were excluded. ATR was measured with a scoliometer, AVR through EOS radiographic imaging, and BSR via surface topographic scanning, Data collection occurred at: preoperative, six-week, three-month, six-month, one-year, and two-year postoperative visits. BSR and AVR were tracked at the preoperative apical vertebral level, and the level with maximum deformity, at each respective timepoint. Generalized estimating equations models were used for statistical analysis. Covariates included age, sex, and body mass index. RESULTS: 49 patients (73.4% female, mean age 14.6±2.2 years, mean preoperative coronal curve angle 57.9°±8.5, and 67% major thoracic) were evaluated. ATR correction was significantly improved at all postoperative timepoints and there was no significant loss of correction. AVR Max and AVR Apex were significantly improved at all timepoints but there was a significant loss of correction for AVR Apex between the six-week and one-year visit (P=0.032). BSR Max achieved significant improvement at the three-month visit. BSR Apex was significantly improved at the three-month and one-year visit. CONCLUSION: ATR and AVR demonstrated significant axial plane correction at two-years postoperative in patients undergoing PSF for AIS. BSR did not maintain significant improvement by the two-year visit.

Early Adherence to Prescribed Brace Wear for Adolescent Idiopathic Scoliosis Is Associated With Future Brace Wear.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To assess if initial adherence to prescribed brace wear for adolescent idiopathic scoliosis (AIS) predicts future adherence and curve improvement. SUMMARY OF BACKGROUND DATA: AIS bracing can be effective if patients adhere to prescribed brace wear. Previous research has associated age, sex, and brace prescription length with future adherence. We hypothesize that a patient's initial adherence to brace wear may be associated with future adherence and outcomes. MATERIALS AND METHODS: Consecutive AIS patients who met the Scoliosis Research Society (SRS) criteria for bracing from 2015 to 2019 at a single center were reviewed. Patients were stratified into groups based on their adherence during the initial one-month brace wean-in period-adherent patients were defined as wearing the brace >80% of the daily prescribed amount. Brace wear was recorded by a thermosensor and assessed during the wean-in period, six-, 12-, and 24-month postbracing appointments. Statistical testing was conducted to analyze if initial adherence was associated with future adherence, curve change, and bracing success -defined as reaching Risser stage 4 with a Cobb angle <40°. RESULTS: Sixty patients (mean age=12.5 yr) were included, of which the majority were females (83%) with thoracic curves (70%). Thirty-two patients were considered adherent, and this cohort demonstrated improved adherence relative to the nonadherent group at the six-, 12-, and 24-month appointments ( P <0.001). Adherent patients also showed a significant reduction in their scoliosis at the 12-month appointment, unlike nonadherent patients ( P <0.001). Ninety-seven percent of adherent patients achieved bracing success compared with 71% of nonadherent ( P =0.016). Females were more likely to be adherent than males. CONCLUSIONS: Initial adherence to prescribed AIS brace wear was associated with future adherence, bracing success, and curve improvement. Early recognition of nonadherence may offer an opportunity for supportive intervention to improve brace wear behavior.

The Effects of Body Mass Index and Spine Flexibility on Surgical Outcomes for Patients With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate the relationship between body mass index (BMI), spine flexibility index (FI), and their combined effects on adolescent idiopathic scoliosis (AIS) surgical outcomes. BACKGROUND: BMI and FI are two factors considered during presurgical planning for AIS correction, but there is sparse research about their relationship. We hypothesize that AIS patients with increased BMI may be associated with decreased FI-a combination which could lead to worsened surgical outcomes. MATERIALS AND METHODS: AIS patients ages 11 to 19 at surgery, who underwent posterior fusion at a single center from 2011 to 2017, were reviewed. Patients without proper radiographs to assess FI, or a previous spine surgical history, were excluded. FI was categorized as stiff (FI<50) or flexible (FI≥50), and patients were separated by major curve region. BMI was categorized as underweight (less than fifth percentile), healthy weight (fifth-85th percentile), overweight (85th-95th percentile), or obese (>95th percentile). Regression analysis was conducted to test BMI and FI's effects on intraoperative, immediate postoperative, and two-year postoperative outcomes. RESULTS: A total of 543 patients (82% female), with an average age of 14.9 years, were included. In all, 346 patients had available two-year data. A 10% increase in BMI was associated with a 1.3% decrease in FI for patients with major thoracolumbar/lumbar curves ( P =0.01). Obese patients were most likely to have a postoperative complication ( P =0.003) or a two-year complication ( P =0.04). Revision surgery occurred after 58% of postoperative complications (15/26) and 80% of two-year complications (4/5). FI was negatively associated with initial curve magnitude ( P <0.001), operative time ( P =0.02), and blood loss ( P =0.02). Overweight patients with flexible curves were 10.0 times more likely to sustain a postoperative complication than healthy weight patients with stiff curves ( P =0.001). CONCLUSIONS: Elevated BMI was associated with decreased FI in patients with major thoracolumbar/lumbar curves. Patients with a high BMI and high FI were associated with the greatest risk of postoperative complication.