Network Meta-analysis: Users' Guide for Surgeons: Part II - Certainty

The efficacy of different segments fixation for treatment thoracolumbar fractures: A Bayesian network meta-analysis

BACKGROUND

We did this network meta-analysis to comprehensively compare the efficacy of different segments [intermediate segment (IS), short segment (SS) and long segment (LS)] in the fixation of thoracolumbar fractures.

METHODS

We searched studies from inception until January 20, 2023 through PubMed, Embase, Web of Science, and the Cochrane Library. All studies comparing different segments in the fixation of thoracolumbar fractures were included in this meta-analysis. Outcomes were anterior vertebral height ratio (AVHR), sagittal Cobb angle (SCA), visual analogue scale score, and implant failure rate. This network meta-analysis was performed by R software with gemtc package.

RESULTS

Finally, a total of 22 studies were finally included in this network meta-analysis. IS (WMD 2.43, 95% CrI 2.04-2.91) was more effective than SS in terms of the AVHR, and the difference was statistically significant. IS was more effective than LS in reducing SCA (WMD -2.87, 95% CrI -3.79 to -1.96) with statistically significant. Compared with SS, IS significantly reduced the SCA with statistically significant (WMD -2.52, 95% CrI -3.31 to -1.72). IS (WMD -2.87, 95% CrI -3.78 to -1.96) was more effective than LS, and the difference was statistically significant. Moreover, IS (WMD -2.52, 95% CrI -3.31 to -1.72) was more effective than SS, and the difference was statistically significant.

CONCLUSION

IS was associated with a significant reduction in SCA, implant failure rate, and visual analogue scale compared to SS and LS, while having the most favorable impact on AVHR among all the treatments assessed.

Comparison of different segments in the fixation of thoracolumbar fractures: a Bayesian network meta-analysis

BACKGROUND

Posterior internal fixation (PIF) is commonly used in the treatment of thoracolumbar fracture (TLF), but there is still no standard for the number of fixed segments. The objective of this meta-analysis was to evaluate the efficacy and safety of short segment (SS), intermediate segment (IS) and long segment (LS) in the fixation of TLF.

METHODS

Two authors independently searched through PubMed, Embase, Cochrane Library and Web of Science for studies of thoracolumbar fracture treated by posterior internal fixation, which were published until the end of April 2021. The Aggregate Data Drug Information System (ADDIS) software was used for data evaluation according to the Markov chain Monte Carlo (MCMC) method based on the Bayesian theorem.

RESULTS

Nineteen trials evaluating a total of 970 patients were enrolled in these studies, of which 340 in the SS group, 429 in the IS group and 201 in the LS group. For anterior vertebral height ratio (AVHR), IS had the highest AVHR, LS had the second highest AVHR. IS also ranked first in reducing visual analogue scale (VAS), SS ranked second. For sagittal Cobb's angle (SCA), LS had the lowest SCA and IS had the second lowest SCA. In terms of adverse events, IS had the lowest implant failure rate and LS had the second lowest implant failure rate.

CONCLUSIONS

IS may be the most desirable treatment option for TLF in reducing SCA, implant failure rate, VAS, and improving AVHR. However, more randomized controlled trials are needed to verify these results.

Network meta-analysis: What is its purpose in Orthopaedic literature?

Systematic reviews, of level-I primary literature, are the gold standard for the formation of Clinical Practice Guidelines in Orthopaedic Surgery. When systematic reviews have multiple groups of data, meta-analyses can be conducted to analyse the direct comparison of the data points (pairwise meta-analysis). Over recent years, statisticians have created a new statistical model called network meta-analyses that can be applied to systematic reviews. network meta-analyses allow for comparison of different treatment outcomes that may or may not have been directly assessed through level-I primary studies. network meta-analyses are appearing more and more in Orthopaedic Surgery literature; therefore, in this article, we discuss what a Network Meta-analysis is and its application in Orthopaedics.

What Is the Relative Effectiveness of the Various Surgical Treatment Options for Distal Radius Fractures? A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

BACKGROUND

Many acceptable treatment options exist for distal radius fractures (DRFs); however, a simultaneous comparison of all methods is difficult using conventional study designs.

QUESTIONS/PURPOSES

We performed a network meta-analysis of randomized controlled trials (RCTs) on DRF treatment to answer the following questions: Compared with nonoperative treatment, (1) which intervention is associated with the best 1-year functional outcome? (2) Which intervention is associated with the lowest risk of overall complications? (3) Which intervention is associated with the lowest risk of complications requiring operation?

METHODS

Ten databases were searched from inception to July 25, 2019. Search and analysis reporting adhered to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Included studies were English-language RCTs that assessed at least one surgical treatment arm for adult patients with displaced DRFs, with less than 20% loss to follow-up. We excluded RCTs reporting on patients with open fractures, extensive bone loss, or ipsilateral upper extremity polytrauma. Seventy RCTs (n = 4789 patients) were included. Treatments compared were the volar locking plate, bridging external fixation, nonbridging external fixation, dynamic external fixation, percutaneous pinning, intramedullary fixation, dorsal plating, fragment-specific plating, and nonoperative treatment. Subgroup analyses were conducted for intraarticular fractures, extraarticular fractures, and patients with an average age greater than 60 years. Mean (range) patient age was 59 years (56 to 63) and was similar across all treatment groups except for dynamic external fixation (44 years) and fragment-specific plating (47 years). Distribution of intraarticular and extraarticular fractures was approximately equal among the treatment groups other than that for intramedullary fixation (73% extraarticular), fragment-specific plating (66% intraarticular) [13, 70], and dorsal plating (100% intraarticular). Outcomes were the DASH score at 1 year, total complications, and reoperation. The minimum clinically important different (MCID) for the DASH score was set at 10 points. The analysis was performed using Bayesian methodology with random-effects models. Rank orders were generated using surface under the cumulative ranking curve values. Evidence quality was assessed using Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methodology. Most studies had a low risk of bias due to randomization and low rates of incomplete follow-up, unclear risk of bias due to selective reporting, and high risk of bias due to lack of patient and assessor blinding. Studies assessing bridging external fixation and/or nonoperative treatment arms had a higher overall risk of bias while studies with volar plating and/or percutaneous pinning treatment arms had a lower risk of bias.

RESULTS

Across all patients, there were no clinically important differences in terms of the DASH score at 1 year; although differences were found, all were less than the MCID of 10 points. Volar plating was ranked the highest for DASH score at 1 year (mean difference -7.34 [95% credible interval -11 to -3.7) while intramedullary fixation, with low-quality evidence, also showed improvement in DASH score (mean difference -7.75 [95% CI -14.6 to -0.56]). The subgroup analysis revealed that only locked volar plating was favored over nonoperative treatment for patients older than 60 years of age (mean difference -6.4 [95% CI -11 to -2.1]) and for those with intraarticular fractures (mean difference -8.4 [95% CI -15 to -2.0]). However, its clinical importance was uncertain as the MCID was not met. Among all patients, intramedullary fixation (odds ratio 0.09 [95% CI 0.02 to 0.84]) and locked volar plating (OR 0.14 [95% CI 0.05 to 0.39]) were associated with a lower complication risk compared with nonoperative treatment. For intraarticular fractures, volar plating was the only treatment associated with a lower risk of complications than nonoperative treatment (OR 0.021 [95% CI < 0.01 to 0.50]). For extraarticular fractures, only nonbridging external fixation was associated with a lower risk of complications than nonoperative treatment (OR 0.011 [95% CI < 0.01 to 0.65]), although the quality of evidence was low. Among all patients, the risk of complications requiring operation was lower with intramedullary fixation (OR 0.06 [95% CI < 0.01 to 0.85) than with nonoperative treatment, but no treatment was favored over nonoperative treatment when analyzed by subgroups.

CONCLUSION

We found no clinically important differences favoring any surgical treatment option with respect to 1-year functional outcome. However, relative to the other options, volar plating was associated with a lower complication risk, particularly in patients with intraarticular fractures, while nonbridging external fixation was associated with a lower complication risk in patients with extraarticular fractures. For patients older than 60 years of age, nonoperative treatment may still be the preferred option because there is no reliable evidence showing a consistent decrease in complications or complications requiring operation among the other treatment options. Particularly in this age group, the decision to expose patients to even a single surgery should be made with caution.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Do External Supports Improve Dynamic Balance in Patients with Chronic Ankle Instability? A Network Meta-analysis

BACKGROUND

To improve ankle stability in patients who have experienced an ankle sprain with residual symptoms of instability and/or objective joint laxity, external supports (such as taping, bracing, and orthotic insoles) are used sometimes. However, available randomized trials have disagreed on whether restraints improve balance in those individuals. In this situation, a network meta-analysis can help because it allows for comparing multiple treatments simultaneously, taking advantage not only of direct but also indirect evidence synthesis.

QUESTIONS/PURPOSES

The aim of this network meta-analysis was to assess (1) the impact of taping and orthotic devices on dynamic postural control in individuals with ankle instability and (2) the presence of a placebo effect in participants treated with sham taping and complications resulting from the administered treatments.

METHODS

We searched the PubMed, Scopus, and CENTRAL databases up to February 13, 2019 for completed studies. Randomized trials assessing the results of real and/or sham taping, wait-and-see protocols, ankle bracing, and foot orthotics for ankle instability as determined by one or more ankle sprains followed by ongoing subjective symptoms and/or mechanical laxity were included. We evaluated dynamic postural control in terms of the Star Excursion Balance Test in the posteromedial direction (SEBT-PM), which is considered the most representative of balance deficits in patients with ankle instability. Standardized mean differences were re-expressed to percentage differences in SEBT-PM, with higher scores representing possible improvement. Subsequently, those data were checked against the established minimal detectable change of 14% for this scale to make judgements on clinical importance. We also assessed the presence of a placebo effect by comparing the results of sham taping with no treatment and complications resulting from the administered treatments. Additionally, we judged the quality of trials using the Cochrane risk of bias tool and quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. A total of 22 trials met our inclusion criteria, 18 of which were deemed to be at a low risk of bias. A network of treatments consisting of 13 studies was created, and the level of evidence was judged to be high. As far as participants' allocation to treatment arms, 85 patients followed a wait-and-see protocol, 29 received placebo taping, 99 were treated with taping, 16 were treated with bracing, 27 were administered insoles, and six individuals were offered a combination of insoles with bracing. Of note, with statistical power set at 80%, a minimum of 16 patients per treatment group was required to provide sufficient statistical power and detect a SEBT-PM percentage difference of 14%.

RESULTS

A network meta-analysis did not demonstrate a benefit of taping or bracing over no treatment (percentage difference in SEBT-PM between taping and bracing versus control: -2.4 [95% CI -6 to 1.1]; p = 0.18, and -7.5 [95% CI -15.9 to 1]; p = 0.08, respectively). This was also the case for sham taping because the measurement increase failed to exceed the minimal detectable change (percentage difference in SEBT-PM between sham taping and untreated control: -1.1 [95% CI -6.9 to 4.7]; p = 0.72). Importantly, there were no reported adverse events after treatment application.

CONCLUSIONS

Evidence of moderate strength indicated that external supports of any type were no more effective than controls in improving dynamic postural control in patients with at least one ankle sprain and residual functional or mechanical deficits. Therefore, implementing those tools as a standalone treatment does not appear to be a viable strategy for the primary management of ankle instability. It is conceivable that combinations of rehabilitation and external supports could be more effective than external supports alone, and future trials should evaluate the potential of such combinations in enhancing not only clinician-reported but also patient-oriented outcomes using long-term follow-up measurements.

LEVEL OF EVIDENCE

Level I, therapeutic study.

No difference in outcomes between femoral fixation methods with hamstring autograft in anterior cruciate ligament reconstruction - A network meta-analysis

BACKGROUND

There is mixed opinion regarding the optimal femoral fixation method for hamstring tendon autograft in anterior cruciate ligament (ACL) reconstruction. Currently, no study exists showing a superior method of femoral fixation, and thus the topic has remained controversial. The purpose of this study is to network meta-analyze the randomized control trials comparing cortical-button (CB), cross-pin (CP) and interference screws (IS) for femoral fixation with hamstring tendon autograft in ACL reconstruction.

METHODS

The literature review was conducted in accordance with the PRISMA guidelines. Randomized control trials comparing CB, CP and IS were included. Clinical outcomes were compared using a frequentist approach to network meta-analysis, with all statistical analysis performed using R, with a p-value <0.05 being considered statistically significant.

RESULTS

There were 11 studies included comparing; 194 patients with CB to 201 patients with CP (6 studies), 48 patients with CB to 50 patients with IS (1 study), and 172 patients with CP to 162 patients with IS (5 studies). One study compared all three groups, including 48 patients with CB, 50 patients with IS, and 52 with CP. There was a mean follow-up time of 26.4 months. No statistically significant difference was found between the fixation methods when evaluating knee stability, functional outcomes, graft failures, or revision procedures.

CONCLUSION

Using a network meta-analysis, our study found that, there was no difference in failure rate, knee stability, functional outcomes or incidence of revision procedures between CB, CP or IS femoral fixation techniques of hamstring tendon autografts in ACL reconstruction.

LEVEL OF EVIDENCE

Level I, network meta-analysis of Level I studies.