Statistical Fragility of Single-Row Versus Double-Row Anchoring for Rotator Cuff Repair: A Systematic Review of Comparative Studies

Outcomes of arthroscopic rotator cuff repair via single-row anchor technique versus transosseous anchorless technique: A randomized controlled trial

Background

Rotator cuff tears can be addressed using various repair techniques. This study sought to compare the clinical and radiologic outcomes and costs after arthroscopic single-row anchor repair and arthroscopic transosseous repair for small to medium-sized tears.

Methods

The study was a prospective randomized clinical trial (registered as trial number PACTR202404475835971 in the Pan African Clinical Trial Registry, Apr 04, 2024) that included 62 patients, randomized into two equal groups. Group A: single-row anchor repair (n = 31) and Group B: transosseous repair (n = 31). Patients were clinically evaluated using the American Shoulder and Elbow Surgeons (ASES) score and Oxford Shoulder Score (OSS), in addition to evaluation of range of motion (ROM) of forward flexion, external rotation (ER), and internal rotation (IR). Total implant costs were calculated and compared.

Results

In both groups, the ROM increased significantly, P < 0.001. The mean differences between preoperative and postoperative forward flexion, ER, and IR were comparable in both groups, P = 0.933, 0.817, and 0.151, respectively. The mean ASES score and OSS improved significantly in both groups at last follow-up, P < 0.001. The mean follow-up ASES score was 91.1 ± 3.5 in Group A and 90.8 ± 2.7 in Group B, P = 0.818. The mean follow-up OSS was 42.4 ± 2.1 in Group A and 41.5 ± 1.9 in Group B, P = 0.214. The average financial cost of operation was significantly lesser in the transosseous group than the anchors group, P < 0.001.

Conclusion

Anchorless transosseous rotator cuff repair can achieve similar excellent functional outcomes as the single-row anchor repair, with equivalent tendon healing results. However, the transosseous technique has substantially lower costs.

Fragility of Statistical Differences Between Surgical Approaches in Total Hip Arthroplasty

BACKGROUND

Total hip arthroplasty (THA) is a successful treatment for hip osteoarthritis, but the optimal surgical approach for this procedure is a topic of debate. This review uses fragility analysis to determine the statistical fragility of randomized controlled trials (RCTs) comparing the 3 most common surgical approaches for THA: direct anterior, direct lateral, and posterior.

MATERIALS AND METHODS

A systematic review was conducted to identify RCTs comparing 2 of the 3 surgical approaches for THA. Dichotomous outcomes and study characteristics were extracted from each study that met the inclusion criteria. Fragility index (FI) and fragility quotient (FQ) were calculated for each significant outcome (P≤.05), and reverse fragility index and quotient (rFI and FQ) were calculated for each nonsignificant outcome (P>.05).

RESULTS

Our search yielded 20 studies in total, with 146 identified dichotomous outcomes. In total, the outcomes had a median FI of 5 and a median rFI of 5. Significant outcomes that favored the anterior approach had a median FI of 6, and significant outcomes that favored the posterior or lateral approach both had a median FI of 1.

CONCLUSION

The RCTs comparing approaches to THA had a median FI of 5, signifying that the reversal of 5 events would be sufficient to change the significance of the entire outcome. This value is comparable to other FI values within the orthopedic literature, but subgroup analyses elucidated areas of greater statistical fragility, particularly in outcomes favoring either the lateral or posterior approach in THA. [Orthopedics. 202x;4x(x):xx-xx.].

The fragility of statistical findings in the intertrochanteric fracture fixation literature: a systematic review of randomized controlled trials

INTRODUCTION

Intertrochanteric fractures are common and can lead to significant disability and morality, particularly in the elderly. Utilizing the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ), this study evaluates the statistical fragility of outcomes reported in intertrochanteric fracture fixation randomized controlled trials (RCTs).

MATERIALS AND METHODS

Data sources: Pubmed, Embase, and MEDLINE were queried for RCTs published between 2010-present.

STUDY SELECTION

RCTs reporting 1:1 categorical, dichotomous outcomes were included. Articles were excluded if they were not RCTs, had over two treatment groups, included in vitro/animal/cadaveric data, and did not feature intertrochanteric fractures.

DATA EXTRACTION

Publication and individual outcome data were collected by three independent reviewers.

DATA SYNTHESIS

FI and rFI were calculated as the number of event reversals required to reverse the statistical significance for each outcome. The FQ was calculated by dividing FI by the study sample size. Subgroup analysis was performed based on outcome types.

RESULTS

Two hundred thirty-two articles were screened, and 52 articles with a total of 370 outcomes were included for analysis. The median FI was 5 (IQR 4-6) with a FQ of 0.05 (IQR 0.032-0.078). 57/370 outcomes were statistically significant with a median FI of 3 (IQR 1-8). 313 outcomes were statistically nonsignificant with a median rFI of 5 (IQR 4-6). The number of patients lost to follow-up was greater than or equal to the FI in 127/370 outcomes (34.32%). Outcomes relating to malunion/nonunion were the most fragile, encompassing 11 outcomes with a median FI of 3 (IQR 2.5-5).

CONCLUSION

Outcomes in intertrochanteric fracture fixation RCTs are fragile as reversal of a few outcomes or maintaining follow-up may alter the significance of study findings. Thus, P-values are recommended to be routinely reported with FI and FQ metrics in order to provide a comprehensive understanding of the statistical robustness of outcomes in orthopedic trauma literature.

LEVEL OF EVIDENCE

I.

Randomized Controlled Trials Evaluating Treatments for Carpometacarpal Arthritis Are Statistically Fragile: A Systematic Review

BACKGROUND

Randomized controlled trials (RCTs) on carpometacarpal (CMC) arthritis have a significant impact on treatment decisions, yet the robustness of their findings is seldom evaluated. This study aims to investigate the statistical fragility of RCTs evaluating treatments for CMC arthritis.

METHODS

PubMed, Embase, and MEDLINE were systematically searched for recent RCTs (2010-2023) evaluating treatment variations for CMC arthritis. The fragility index (FI) or reverse FI (rFI) was calculated for each dichotomous outcome, representing the number of event reversals required to alter statistical significance for significant and nonsignificant outcomes, respectively. The fragility quotient (FQ) was determined by dividing the FI or rFI by the total sample size.

RESULTS

Of the 46 RCTs screened for inclusion, 15 were included for analysis, resulting in 46 total outcomes. The median FI across the 46 outcomes was 4.5, with an associated median FQ (mFQ) of 0.075. Statistically significant outcomes were more fragile (mFQ = 0.026) than nonsignificant outcomes (mFQ = 0.079). In 66.7% of significant outcomes, losses to follow-up were greater than that outcome's FI. Postoperative functional tests, adverse events, and patient satisfaction were the most common outcome categories reported, with mFQ's of 0.170, 0.066, and 0.068, respectively.

CONCLUSIONS

Outcomes reported in RCTs studying CMC arthritis are statistically fragile, particularly among significant outcomes where losses to follow-up may have also affected outcome significance. For future studies, we recommend reporting fragility statistics along with P values to provide hand surgeons another metric by which to gauge the results of CMC RCTs.

The statistical stability of clavicle fracture management: A systematic review of randomized controlled trials with fragility analysis

BACKGROUND

Randomized controlled trials (RCTs) represent the highest level of evidence in guiding the management of clavicle fractures. They are conducted to ensure that evidence drives the basis of treatment algorithms. Relying solely on P values to assess orthopedic RCTs may be deceptive and challenge the validity of the studies.

OBJECTIVE

To evaluate the degree of statistical fragility in the clavicle fracture literature using the fragility index (FI) and fragility quotient (FQ).

METHODS

A systematic search strategy using the Medline, PubMed, and Embase databases was used to find all dichotomous data for randomized controlled trials (RCTs) in clavicle fracture research from 2000 to 2024. The FI of each outcome was calculated by reversing a single outcome event until significance was reversed. The FQ was calculated by dividing each fragility index by the study sample size. The interquartile range (IQR) was also calculated for the FI and FQ.

RESULTS

Of the 3646 articles screened, 81 met the search criteria, with 30 RCTs evaluating clavicle fractures included for analysis. There were 250 total outcomes, where 62 significant and 188 nonsignificant outcomes were identified. The overall FI and FQ were 4 (IQR 3-5) and 0.045 (IQR 0.024-0.080). Statistically significant and nonsignificant outcomes had an FI of 3.5 (IQR 2-7) and 4 (IQR 3-5), respectively. Regarding loss to follow-up (LTF), 63.3% (19) reported LTF greater or equal to the overall FI of 4.

CONCLUSION

When scrutinizing management algorithms relying on statistical analysis, we recommend including the FI and FQ alongside the P value.

The Statistical Fragility of Marrow Stimulation for Cartilage Defects of the Knee: A Systematic Review of Randomized Controlled Trials

OBJECTIVE

Marrow stimulation is used to address knee cartilage defects. In this study, we used the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ) to evaluate statistical fragility of outcomes reported in randomized controlled trials (RCTs) evaluating marrow stimulation.

DESIGN

PubMed, Embase, and MEDLINE were queried for recent RCTs (January 1, 2010-September 5, 2023) assessing marrow stimulation for cartilage defects of the knee. The FI and rFI were calculated as the number of outcome event reversals required to alter statistical significance for significant and nonsignificant outcomes, respectively. The FQ was determined by dividing the FI by the study sample size.

RESULTS

Across 155 total outcomes from 21 RCTs, the median FI was 3 (interquartile range [IQR], 2-5), with an associated median FQ of 0.067 (IQR, 0.033-0.010). Thirty-two outcomes were statistically significant, with a median FI of 2 (IQR, 1-3.25) and FQ of 0.050 (IQR, 0.025-0.069). Ten of the 32 (31.3%) outcomes reported as statistically significant had an FI of 1. In total, 123 outcomes were nonsignificant, with a median rFI of 3 (IQR, 2-5). Studies assessing stem cell augments were the most fragile, with a median FI of 2. In 55.5% of outcomes, the number of patients lost to follow-up was greater than or equal to the FI.

CONCLUSION

Statistical findings in RCTs evaluating marrow stimulation for cartilage defects of the knee are statistically fragile. We recommend combined reporting of P-values with FI and FQ metrics to aid in the interpretation of clinical findings in comparative trials assessing cartilage restoration.

The Fragility of Statistical Significance in the Use of Aspirin in Prevention of Venous Thromboembolism Events Following Total Joint Arthroplasty: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Comparative studies often use the p value to convey statistical significance, but fragility indices (FI) and fragility quotients (FQ) may better signify statistical strength. The use of aspirin as venous thromboembolism (VTE) chemoprophylaxis following elective arthroplasty has been debated between the orthopedic and cardiac fields. The purpose of this study was to apply both the FI and FQ to evaluate the degree of statistical fragility in the total joint arthroplasty (TJA) literature regarding aspirin (ASA) use for VTE prevention. Methods: We performed a systematic search for TJA clinical trials from 2004 to 2023 reporting comparisons between ASA and other chemoprophylaxis methods for VTE. The FI of each outcome was calculated through reversal of a single outcome event until significance was reversed. The FQ was calculated by dividing each fragility index by study sample size and interquartile range (IQR) was calculated. SPSS Meta-analysis function was used to calculate the Mean Effect Size Estimate and 95% Confidence Intervals for each outcome. Results: Of 245 articles screened, 39 met search criteria, with 10 RCTs included for analysis (n = 11,481 patients). There were 38 outcome events reported, with three significant (p < 0.05) outcomes and 35 non-significant (p > 0.05) outcomes identified. The overall FI and FQ for all 38 outcomes were 6 (IQR: 5-7) and 0.059 (IQR: 0.044-0.064), respectively. Seven studies (70%) reported a loss-to-follow-up (LTF) greater than the overall FI. There was no increased risk of DVT, PE, or mortality with use of ASA (all p > 0.2). Conclusions: Despite showing non-inferiority in preventing venous thromboembolic events in TJA overall, the highest-level peer-reviewed literature concerning aspirin use following total joint arthroplasty is considered statistically fragile due to high loss-to-follow-up. In addition to the reporting of the p value, the fragility index and quotient can further provide insight into the strength and trustworthiness of outcome measures.

The Statistical Fragility of Lateral Extra-articular Tenodesis Research: A Systematic Review

Background

A P value of <.05 is often used to denote statistical significance; however, in many scenarios, this threshold is vulnerable to a small number of outcome reversals. This study joins a body of studies within the orthopaedic literature that evaluate the statistical fragility of existing research via metrics such as fragility index (FI) and fragility quotient (FQ).

Purpose/Hypothesis

The purpose of this study was to investigate the statistical fragility of randomized controlled trials (RCTs) and comparative studies on the topic, given the resurgent interest in lateral extra-articular tenodesis (LET) to augment primary or revision anterior cruciate ligament reconstruction (ACLR). It was hypothesized that the outcomes reported in these studies would be statistically fragile.

Study Design

Systematic review; Level of evidence, 4.

Methods

Comparative studies and RCTs regarding LET as an adjunct procedure to ACLR published between 2000 and 2022 were analyzed. Descriptive characteristics, dichotomous outcomes, and continuous outcomes were extracted. The FI and continuous FI (CFI) were calculated by the number of event reversals to change significance; the FQ and continuous FQ (CFQ) were calculated to normalize the fragility metrics per sample size.

Results

Of 455 studies screened, 29 studies were included (9 RCTs, 20 comparative); 79.3% of included studies were published after 2020. A total of 48 dichotomous and 265 continuous outcomes were analyzed. The median FI was 9.0 (IQR, 7.0-13.3), with FQ of 0.1 (IQR, 0.04-0.17); the median CFI was 7.8 (IQR, 4.2-19.6), with CFQ of 0.12 (IQR, 0.08-0.19). The FQ and CFQ for studies on LET with revision ACLR were larger (0.117 and 0.113, respectively) than those focused on primary ACLR (0.042 and 0.095, respectively).

Conclusion

Studies focused on LET with primary ACLR were more fragile than those on LET with revision, which suggests that further research on the indications for LET with primary ACLR is necessary. Future orthopaedic comparative research should include fragility metrics alongside traditional P values.

Statistical Outcomes Guiding Periprosthetic Joint Infection Prevention and Revision Are Fragile: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Dichotomous outcomes are frequently reported in orthopaedic research and have substantial clinical implications. This study utilizes the fragility index (FI) and fragility quotient (FQ) metrics to determine the statistical stability of outcomes reported in total joint arthroplasty randomized controlled trials (RCTs) relating to periprosthetic joint infection (PJI).

METHODS

The RCTs that reported dichotomous data related to PJI published between January 1, 2010, and December 31, 2022, were evaluated. The FI and reverse FI (RFI) were defined as the number of outcome event reversals required to reverse the significance of significant and nonsignificant outcomes, respectively. The FQ was determined by dividing the FI or RFI by the respective sample size. There were 108 RCTs screened, and 17 studies included for analysis.

RESULTS

A total of 58 outcome events were identified, with a median FI of 4 (interquartile range [IQR] 2 to 5) and associated FQ of 0.0417 (IQR 0.0145 to 0.0602). The 13 statistically significant outcomes had a median FI of 1 (IQR 1 to 2) and FQ of 0.00935 (IQR 0.00629 to 0.01410). The 45 nonsignificant outcomes had a median RFI of 4 (IQR 3 to 5) and FQ of 0.05 (IQR 0.0361 to 0.0723). The number of patients lost to follow-up was greater than or equal to the FI in 46.6% of outcomes.

CONCLUSIONS

Statistical outcomes in RCTs analyzing PJI are fragile and may lack statistical integrity. We recommend a comprehensive fragility analysis, with the reporting of FI and FQ metrics, to aid in the interpretation of outcomes in the total joint arthroplasty literature.

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.

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.

Augmentation of a Transosseous-Equivalent Repair in Posterosuperior Nonacute Rotator Cuff Tears With a Bioinductive Collagen Implant Decreases the Retear Rate at 1 Year: A Randomized Controlled Trial

PURPOSE

To determine whether the addition of a bioinductive collagen implant (BCI) over a transosseous equivalent (TOE) repair of medium-to-large posterosuperior rotator cuff tears improves the healing rate determined by magnetic resonance imaging (MRI) at 12-month follow-up.

METHODS

A Level I randomized controlled trial was performed in 124 subjects with isolated, symptomatic, reparable, full-thickness, medium-to-large posterosuperior nonacute rotator cuff tears, with fatty infiltration ≤2. These were randomized to 2 groups in which an arthroscopic posterosuperior rotator cuff tear TOE repair was performed alone (Control group) or with BCI applied over the TOE repair (BCI group). The primary outcome was the retear rate (defined as Sugaya 4-5) determined by MRI at 12 months of follow-up. Secondary outcomes were characteristics of the tendon (Sugaya grade and thickness of the healed tendon) and clinical outcomes (pain levels, EQ-5D-5L, American Shoulder and Elbow Surgeons, and Constant-Murley scores) at 12 months of follow-up.

RESULTS

Of the 124 randomized patients, 122 (60 in the BCI group and 62 in the Control group) were available for MRI evaluation 12.2 ± 1.02 months after the intervention. There were no relevant differences in preoperative characteristics. Adding the BCI reduced the retear rate (8.3% [5/60] in the BCI group vs 25.8% [16/62] in the Control group, P = .010; relative risk of retear of 0.32 [95% confidence interval 0.13-0.83]). Sugaya grade was also better in the BCI group (P = .030). There were no differences between groups in the percentage of subjects who reached the MCID for CMS (76.7% vs 81.7%, P = .654) or American Shoulder and Elbow Surgeons (75% vs 80%, P = .829), in other clinical outcomes or in complication rates at 12.4 ± 0.73 (range 11.5-17) months of follow-up.

CONCLUSIONS

Augmentation with a BCI of a TOE repair in a medium-to-large posterosuperior rotator cuff tear reduces the retear rate at 12-month follow-up by two-thirds, yielding similar improvements in clinical outcomes and without increased complication rates.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

The Statistical Fragility of Tranexamic Acid Use in the Orthopaedic Surgery Literature: A Systematic Review of Randomized Controlled Trials

INTRODUCTION

Randomized controlled trials (RCTs) represent the highest level of evidence in orthopaedic surgery literature, although the robustness of statistical findings in these trials may be unreliable. We used the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ) to evaluate the statistical stability of outcomes reported in RCTs that assess the use of tranexamic acid (TXA) across orthopaedic subspecialties.

METHODS

PubMed, EMBASE, and MEDLINE were queried for RCTs (2010-present) reporting dichotomous outcomes with study groups stratified by TXA administration. The FI and rFI were defined as the number of outcome event reversals needed to alter the significance level of significant and nonsignificant outcomes, respectively. FQ was determined by dividing the FI or rFI by sample size. Subgroup analyses were conducted based on orthopaedic subspecialty.

RESULTS

Six hundred five RCTs were screened with 108 studies included for analysis comprising 192 total outcomes. The median FI of the 192 outcomes was 4 (IQR 2 to 5) with an associated FQ of 0.03 (IQR 0.019 to 0.050). 45 outcomes were reported as statistically significant with a median FI of 1 (IQR 1 to 5) and associated FQ of 0.02 (IQR 0.011 to 0.034). 147 outcomes were reported as nonsignificant with a median rFI of 4 (IQR 3 to 5) and associated FQ of 0.04 (IQR 0.023 to 0.051). The adult reconstruction, trauma, and spine subspecialties had a median FI of 4. Sports had a median FI of 3. Shoulder and elbow and foot and ankle had median FIs of 6.

DISCUSSION

Statistical outcomes reported in RCTs on the use of TXA in orthopaedic surgery are fragile. Reversal of a few outcomes is sufficient to alter statistical significance. We recommend reporting FI, rFI, and FQ metrics to aid in interpreting the outcomes reported in comparative trials.

Fragile Statistical Findings in Randomized Controlled Trials Evaluating Autograft Versus Allograft Use in Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To analyze the statistical stability of randomized controlled trials (RCTs) evaluating the surgical management of autografts versus allografts in the anterior cruciate ligament reconstruction (ACLR) literature and calculate the fragility index (FI) and fragility quotient and explore a subgroup analysis by calculating the proportion of outcome events where the FI was less than the number of patients lost to follow-up.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic search in the PubMed and Cochrane databases to identify RCTs published between 2000 and 2022 that investigated the use of autografts versus allografts in ACLR literature and reported dichotomous data. The fragility index of each dichotomous variable was calculated through the reversal of a single outcome event until significance was reversed. The fragility quotient was calculated by dividing each fragility index by the study sample size. The interquartile range also was calculated.

RESULTS

Of the 4407 articles screened, 23 met the search criteria, with 11 RCTs evaluating ALCR using autografts and allografts included for analysis. Two hundred and 18 outcome events with 32 significant (P < .05) outcomes and 186 nonsignificant (P ≥ .05) outcomes were identified. The overall fragility index and fragility quotient for all 218 outcomes were 6 subjects (interquartile range 5-8) and 0.058 (interquartile range 0.039-0.077). Fragility analysis of statistically significant outcomes and nonsignificant outcomes had a fragility index of 3.5 (interquartile range 1-5.5) and 6 (interquartile range 5-8), respectively. All of the studies reported a loss to follow-up where 45.5% (5) reported a loss to follow-up greater or equal to 6.

CONCLUSIONS

The RCTs in the ACLR peer-reviewed literature evaluating autograft versus allograft use are vulnerable to a small number of outcome event reversals and exemplify significant statistical fragility in statistically significant findings.

LEVEL OF EVIDENCE

Level I, systematic review of Level I studies.

Randomized Controlled Trials Comparing Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autografts in Anterior Cruciate Ligament Reconstruction Surgery Are Statistically Fragile: A Systematic Review

PURPOSE

To assess the statistical fragility of recently published randomized controlled trials (RCTs) comparing the use of hamstring tendon autograft with bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction.

METHODS

The PubMed, Embase, and MEDLINE databases were queried for RCTs published since 2010 comparing autograft type (bone-patellar tendon-bone vs hamstring tendon) in ACL reconstruction surgery. The fragility index (FI) and reverse FI (rFI) were determined for significant and nonsignificant outcomes, respectively, as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) and reverse FQ, representing fragility as a proportion of the study population, were calculated by dividing the FI and rFI, respectively, by the sample size.

RESULTS

We identified 19 RCTs reporting 55 total dichotomous outcomes. The median FI of the 55 total outcomes was 5 (interquartile range [IQR], 4-7), meaning a median of 5 outcome event reversals would alter the outcomes' significance. Five outcomes were reported as statistically significant with a median FI of 4 (IQR, 2-6), meaning a median of 4 outcome event reversals would change outcomes to be nonsignificant. Fifty outcomes were reported as nonsignificant with a median rFI of 5 (IQR, 4-7), meaning a median of 5 outcome event reversals would change outcomes to be significant. The FQ and reverse FQ for significant and nonsignificant outcomes were 0.025 (IQR, 0.018-0.045) and 0.082 (IQR, 0.041-0.106), respectively. For 61.8% of outcomes, patients lost to follow-up exceeded the corresponding FI or rFI.

CONCLUSIONS

There is substantial statistical fragility in recent RCTs on autograft choice in ACL reconstruction surgery given that altering a few outcome events is sufficient to reverse study findings. For over half of outcomes, maintaining patients lost to follow-up may have been sufficient to reverse study conclusions.

CLINICAL RELEVANCE

We recommend co-reporting FIs and P values to provide a more comprehensive representation of a study's conclusions when conducting an RCT.

Editorial Commentary: The Statistical Fragility Index of Medical Trials Is Low By Design: Critical Evaluation of Confidence Intervals Is Required

The Fragility Index (FI) provides the number of patients whose outcome would need to have changed for the results of a clinical trial to no longer be statistically significant. Although it's a well-intended and easily interpreted metric, its calculation is based on reversing a significant finding and therefore its interpretation is only relevant in the domain of statistical significance. Its interpretation is only relevant in the domain of statistical significance. A well-designed clinical trial includes an a priori sample size calculation that aims to find the bare minimum of patients needed to obtain statistical significance. Such trials are fragile by design! Examining the robustness of clinical trials requires an estimation of uncertainty, rather than a misconstrued, dichotomous focus on statistical significance. Confidence intervals (CIs) provide a range of values that are compatible with a study's data and help determine the precision of results and the compatibility of the data with different hypotheses. The width of the CI speaks to the precision of the results, and the extent to which the values contained within have potential to be clinically important. Finally, one should not assume that a large FI indicates robust findings. Poorly executed trials are prone to bias, leading to large effects, and therefore, small P values, and a large FI. Let's move our future focus from the FI toward the CI.

The statistical fragility of outcomes in calcaneus fractures: A systematic review of randomized controlled trials

INTRODUCTION

The purpose of this study was to utilize the fragility index to assess the robustness of randomized controlled trials (RCTs) evaluating the management of calcaneus fractures. We hypothesize that the dichotomous outcomes in calcaneus fracture literature will be statistically fragile and comparable to other orthopedic specialties.

METHODS

We performed a PubMed search for calcaneus fracture RCTs from 2000 to 2022 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The fragility index (FI) of each outcome was calculated through the reversal of a single outcome event until significance was reversed. The fragility quotient (FQ) was calculated by dividing each fragility index by study sample size. The interquartile range (IQR) was also calculated for the FI and FQ.

RESULTS

Of the 3003 studies screened, 97 met the search criteria, with 19 RCTs evaluating calcaneus fractures included in the analysis. Seventy-nine dichotomous outcomes with 30 significant (P < 0.05) outcomes and 49 with nonsignificant (P> 0.05) outcomes were identified. The overall FI and FQ of all outcomes were 6 (IQR 3-8) and 0.067 (IQR 0.032-0.100), respectively.

CONCLUSIONS

The literature surrounding calcaneus fractures may not be as statistically stable as previously thought. The sole reliance on the P value may depict misleading results. We, therefore, recommend reporting the P value in conjunction with the FI and FQ to give a robust contextualization of clinical findings in the calcaneus fracture literature.

The statistical fragility of the management options for reverse shoulder arthroplasty: a systematic review of randomized control trial with fragility analysis

Reverse shoulder arthroplasty (RSA) is used in the treatment of traumatic and arthritic pathologies, with expanding clinical indications and as a result there has been an increase in clinical research on the topic. The purpose of this study was to examine the statistical fragility of randomized control trials (RCTs) reporting outcomes from RSA. A systematic search was undertaken to find RCTs investigating RSA. The Fragility Index (FI) was calculated using Fisher's exact test, by sequentially altering the number of events until there was a reversal of significance. The Fragility Quotient (FQ) was calculated by dividing the FI by the trial population. Each trial was assigned an overall FI and FQ calculated as the median result of its reported findings. Overall, 19 RCTs warranted inclusion in the review, representing 1146 patients, of which 41.2% were male, with a mean age of 74.2 ± 4.3 years and mean follow-up of 22.1 ± 9.9 months. The median RCT population was 59, with a median of 9 patients lost to follow-up. The median FI was 4.5, and median FQ was 0.083, indicating more patients did not complete the trial than the number of outcomes which would have to change to reverse the finding of significance. This review found that the RCT evidence for RSA management may be vulnerable to statistical fragility, with a handful of events required to reverse a finding of significance.

The reverse fragility index: RCTs reporting non-significant differences in failure rates between hamstring and bone-patellar tendon-bone autografts have fragile results

PURPOSE

The reverse fragility index (RFI) is a novel metric to appraise the results of studies reporting statistically non-significant results. The purpose of this study was to determine the statistical robustness of randomized controlled trials (RCTs) reporting non-significant differences in anterior cruciate ligament reconstruction (ACLR) graft failure rates, defined as re-rupture/revision ACLR rate, between hamstring tendon (HT) and bone-patellar tendon-bone (BTB) autografts by calculating RFIs.

METHODS

A systematic review was performed to identify RCTs that compared HT to BTB grafts for ACLR through January 2022. Studies reporting non-significant differences in graft re-rupture and revision ACLR rate (n.s.) were included. The RFI, defined as the fewest number of event reversals needed to change the non-significant graft re-rupture/revision outcome to statistically significant (P < 0.05), was recorded for each study. In addition, the number of studies in which the loss to follow-up exceeded the RFI was recorded.

RESULTS

Among the 16 included RCTs, the median (interquartile range [IQR]) sample size was 71 (64-114), and the median (IQR) total number of graft re-rupture/revision ACLR events was 4 (4-6). The median (IQR) graft re-rupture/revision ACLR rate was 4.3% (3.0-6.4) overall, 4.1% (2.6-6.7) in the BTB group, and 5.4% (3.0-6.3) in the HT group. The median (IQR) RFI was 3 (3-4), signifying that a reversal of the outcome in 3 patients in one arm was needed to flip the studies' result from non-significant to statistically significant (P < 0.05). The median (IQR) number of participants lost to follow-up was 11 (3-13), and 13 (81.3%) of the included studies had a loss to follow-up greater than the studies' RFI.

CONCLUSION

The results of RCTs reporting statistically non-significant re-rupture/revision ACLR rates between HT and BTB autografts would become significant if the outcome were reversed in a small number of patients-a number that was less than the loss to follow-up in the majority of studies. Thus, the neutrality of these studies is fragile, and a true statistically significant difference in re-rupture/revision rates may have been undetected.

LEVEL OF EVIDENCE

Level I.

The statistical fragility of the distal fibula fracture literature: A systematic review of randomized controlled trials

BACKGROUND

The purpose of this study was to apply both the fragility index (FI) and fragility quotient (FQ) to evaluate the degree of statistical fragility in the distal fibular fracture (DFF) literature. We hypothesized that the dichotomous outcomes within the DFF literature are statistically fragile.

METHODS

We performed a PubMed search for distal fibular fractures clinical trials from 2000 to 2022 reporting dichotomous outcomes. The FI of each outcome was calculated through the reversal of a single outcome event until significance was reversed. The FQ was calculated by dividing each fragility index by study sample size. The interquartile range (IQR) was also calculated for the FI and FQ.

RESULTS

Of the 1158 articles screened, 23 met the search criteria, with six RCTs included for analysis. Forty-five outcome events with 5 significant (p < 0.05) outcomes and 40 nonsignificant (p ≥ 0.05) outcomes were identified. The overall FI and FQ was 5 (IQR 4-6) and 0.089 (IQR 0.061-0.107), respectively.

CONCLUSIONS

The randomized controlled trials in the peer-reviewed distal fibular fracture literature may not be as robust as previously thought, as incorporating statistical analyses solely on a P value threshold is misleading. Standardized reporting of the P value, FI and FQ can help the clinician reliably draw conclusions based on the fragility of outcome measures.

The Statistical Fragility of Orbital Fractures: A Systematic Review of Randomized Controlled Trials

BACKGROUND

The P value has often been used as a tool to determine the statistical significance and evaluate the statistical robustness of study findings in orthopedic literature. The purpose of this study is to apply both the fragility index (FI) and the fragility quotient (FQ) to evaluate the degree of statistical fragility in orbital fracture literature. We hypothesized that the dichotomous outcomes within the orbital fracture literature will be vulnerable to a small number of outcome event reversals and will be statistically fragile.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), the authors identified all dichotomous data for randomized controlled trials (RCTs) in orbital fracture literature and performed a PubMed search from 2000 to 2022. The FI of each outcome was calculated through the reversal of a single outcome event until significance was reversed. The FQ was calculated by dividing each FI by study sample size. The interquartile range (IQR) was also calculated for the FI and FQ.

RESULTS

Of the 3,329 studies screened, 28 met the criteria with 10 RCTs evaluating orbital fractures included for analysis. A total of 58 outcome events with 22 significant (P < .05) outcomes and 36 nonsignificant (P ≥ .05) outcomes were identified. The overall FI and FQ for all 58 outcomes was 5 (IQR: 4 to 5) and 0.140 (IQR: 0.075 to 0.250), respectively. Fragility analysis of statistical significant outcomes and nonsignificant outcomes had an FI of 3.5 with no IQR and 5 (IQR 4-5), respectively. All of the studies reported a loss to follow-up data, where 20% (2) was greater than the overall FI of 5.

CONCLUSION

The orbital fracture literature provides treatment guidance by relying on statistical significant results from RCTs. However, the RCTs in the orbital fracture peer-reviewed literature may not be statistically stable as previously thought. The sole reliance of the P value may depict misleading results. Thus, we recommend standardizing the reporting of the P value, FI, and FQ in the orbital fracture literature to aid readers in reliably drawing conclusions based on fragility outcome measures impacting clinical decision-making.

The fragility of statistical significance in distal femur fractures: systematic review of randomized controlled trials

PURPOSE

The purpose of this study was to apply both the fragility index (FI) and fragility quotient (FQ) to evaluate the degree of statistical fragility in the distal femur fracture (DFF) literature. We hypothesized that the dichotomous outcomes within the DFF literature are statistically fragile.

METHODS

Using preferred reporting items for systematic reviews and meta-analyses, we performed a PubMed search for distal femur fractures clinical trials from 2000 to 2022 reporting dichotomous outcomes. The FI of each outcome was calculated through the reversal of a single outcome event until significance was reversed. The FQ was calculated by dividing each fragility index by study sample size. The interquartile range (IQR) was also calculated for the FI and FQ.

RESULTS

Of the 4258 articles screened, 92 met the search criteria, with eleven RCTs included for analysis. Ninety eight outcome events with 25 significant (P < 0.05) outcomes and 73 nonsignificant (P > 0.05) outcomes were identified. The overall FI and FQ for all 98 outcomes were 5 (IQR 4-6) and 0.130 (IQR 0.087-0.174), respectively. Three studies (33.3%) reported loss to follow (LTF) greater than 5.

CONCLUSIONS

The randomized controlled trials in the peer-reviewed distal femur fracture literature may not be as robust as previously thought, as incorporating statistical analyses solely on a P value threshold is misleading. Standardized reporting of the P value, FI and FQ can help the clinician reliably draw conclusions based on the fragility of outcome measures.

Arthroscopic therapy of rotator cuff diseases: A bibliometric study of the past 2 decades (2002–2021)

Purpose

Rotator cuff diseases, as a common cause of shoulder pain and disability, have seriously affected the patients' daily life. Rotator cuff repair techniques have been a hot topic in the arthroscopic therapy field. Our study was to use bibliometrics analysis to clarify the current status and research trends in the field of arthroscopic therapy of rotator cuff diseases.

Methods

The publications relating to arthroscopic therapy of rotator cuff diseases published from 2001 to 2021 were obtained from the Web of Science Core Collection (WoSCC) database. The R software and VOSviewer software were used for the cross-sectional bibliometric and scientometric analysis.

Results

A total of 4,567 publications about arthroscopic therapy of rotator cuff diseases published between 2002 and 2021 retrieved from the WoSCC database were analyzed in our study. The results showed that the United States made the largest contribution to this field. The most relevant institutions were Seoul National University, Rush University, and Hospital for Special Surgery. Stephen S Burkhart was the most relevant researcher in this field with the largest number of publications, as well as the highest H-index and G-index. The journal ARTHROSCOPY contributed the largest number of publications in the past 2 decades. Considering the H-index and G-index, ARTHROSCOPY was also the journal with the largest impact in this field.

Conclusions

Arthroscopic Therapy of Rotator Cuff Diseases Related research presented a rising trend in the past 2 decades. The United States can be regarded as the leader because of its huge contributions to this field. The journal ARTHROSCOPY published the largest number of publications in this field. It can be predicted that research about advanced arthroscopic techniques and postoperative pain management of patients with rotator cuff diseases will be the next research hotspots in the following years.