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  • Systematic review
  • Open access
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Different internal fixation methods for unstable distal clavicle fractures in adults: a systematic review and network meta-analysis

Abstract

Background

Surgical treatment is advised for unstable distal clavicle fractures (UDCFs). Various kinds of internal fixation methods have been used, but the best fixation is still controversial.

Methods

We systematically searched all studies comparing postoperative outcomes of coracoclavicular (CC) reconstruction (TightRope, EndoButton, Mersilene tape, suture anchor or suture), fracture osteosynthesis (clavicular hook plate (HP), locking compression plate (LCP), Kirschner wire and tension band (KWTB), Kirschner wire (KW)), and a combination of the two methods (LCP + CC or KWTB + CC) for UDCF in PubMed, Web of Science Core Collection via Ovid, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and China Biology Medicine (CBM) databases up to September 16, 2021, with no language restrictions. A network meta-analysis (NMA) was conducted to integrate direct and indirect evidence and assess the relative effects of the internal fixation methods. The probability of being the best treatment was assessed by the surface under the cumulative ranking curve (SUCRA).

Results

A total of 41 studies were included, involving 1969 patients and seven internal fixation methods. The NMA showed that LCP + CC fixation was associated with better efficacy (odds ratio (OR) 0.60, 95% CI 0.19–1.02, probability rank = 0.93) and fewer complications (odds ratio (OR) 0.22, 95% CI 0.09–0.51, probability rank = 0.69) than any other internal fixation method for UDCFs. The SUCRA probabilities of LCP + CC fixation were 98.6% for the Constant–Murley score and 93.9% for total complications.

Conclusions

The results of this study indicate that LCP + CC appears to be the best internal fixation method for UDCF. Limited to the quality and quantity of the included studies, much larger and higher-quality RCTs are required to confirm these conclusions.

Introduction

Distal clavicle fractures (DCFs) are fractures located in the lateral third of the clavicle and account for 10–30% of clavicle fractures [1,2,3]. Neer [3] divided DCFs into five types based on the location of the fracture line in relation to the coracoclavicular (CC) ligament. Type II and type V fractures are unstable distal clavicle fractures (UDCFs), which often involve significant displacement caused by the loss of the coracoclavicular ligament from the proximal fragment and have a high rate of nonunion with conservative treatment [4, 5]. Surgical treatment is advocated for all UDCFs.

Surgical treatment for UDCFs is always a challenge for surgeons [6]. The difficulty of the treatment is due to the distal fragment of the fracture being too small for effective fixation, which can counteract the weight of the distal limb and the strong pull on the proximal fragment by the trapezius muscle. There are various fixation methods for UDCFs, including CC reconstruction [7, 8] (TightRope, EndoButton, Mersilene tape, suture anchors or sutures), fracture osteosynthesis (clavicular hook plate (HP) [9, 10], locking compression plate (LCP) [11], Kirschner wire and tension band (KWTB) [12], or Kirschner wire (KW) [13]), and a combination of the two methods (LCP + CC [14, 15] or KWTB + CC [16]). HPs are the most widely used internal fixators for UDCFs [17]. Clavicle HPs are inserted under the acromion through the distal hook and fixed proximally to the clavicle, forming a lever that maintains fracture reduction, which is consistent with the anatomy and biomechanics of the acromioclavicular joint. However, this internal fixation method also has complications such as subacromial osteolysis, rotator cuff injury, subacromial impingement and joint stiffness [18, 19]. Compared with HP fixation, arthroscopy-assisted CC reconstruction yields higher satisfaction from patients due to the minimally invasive surgical procedure with small wounds, minimal pain, good functional recovery, and no additional surgery is necessary to extract the internal implants [20]; LCP fixation also requires a smaller incision and significantly reduces the implant removal rate and postoperative complications [21]. CC ligament reconstruction may not be required when LCP is used to treat UDCFs [14]. There is still controversy regarding the optimal internal fixation method for UDCFs.

Several meta-analyses have compared the effectiveness and safety of different internal fixation methods for UDCFs [19, 22,23,24,25,26]. However, published meta-analyses did not include combined fixation methods (i.e., LCP + CC) and had a low level of evidence and high heterogeneity among the outcome parameters due to the small number of papers included. Therefore, we undertook a systematic review and network meta-analysis (NMA) of studies that compared the postoperative outcomes (incision size, operation time, blood loss, union time, Constant Murley Score (CMS), University of California at Los Angeles score (UCLAs), and CC distance (CCD)) and complications (total complications, implant-related complications, nonunion and delayed union, reoperation) of different internal fixation methods for UDCFs.

Materials and methods

Search strategies

We searched the PubMed, Web of Science Core Collection via Ovid, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and China Biology Medicine (CBM) databases to identify comparative studies of different internal fixation methods for UDCFs. All databases were searched from inception to September 16, 2021, with no language restrictions. The search strategy was as follows: [[(distal clavicle fracture) OR (lateral clavicle fracture)] AND (fracture fixation, internal)]. The search strategy for PubMed is described in Additional file 1: Appendix 1. An additional manual search of the reference lists of the included studies or any other relevant publications was also conducted independently by two investigators (Yinglong Xu and Hai Dai) to identify other eligible studies.

Inclusion and exclusion criteria

We included comparable studies (cohort, case–control, and randomized controlled trials (RCTs)) that compared at least 2 kinds of internal fixation methods for acute UDCF in adults. Noncomparative studies, paediatric studies, or studies on acromioclavicular joint dislocation, nonunion, or shaft or medial fracture of the clavicle were excluded. Studies without any data on these outcomes (incision size, operation time, blood loss, union time, CMS, UCLAs, CCD, total complications, implant-related complications, nonunion and delayed union, and reoperation) were excluded. Pathological fractures and duplicate publications were also excluded.

Study selection and data extraction

All records identified from the 5 electronic databases were downloaded and imported into EndNote X9 for literature management. Two reviewers (Yinglong Xu and Hai Dai) screened the literature independently. First, duplications were removed from the identified studies through automatic and manual checks, and then irrelevant studies were excluded by title and abstract screening. Finally, the full text of the rest of the potential studies was reviewed for definitive inclusion. Reasons for not eligible or excluded studies were documented. The differences between the two reviewers were resolved by consensus and discussion with a third author. (Zonggui Huang).

Two reviewers (Yinglong Xu and Xiaobo Guo) independently used standardized data extraction forms to extract the details of the included studies, including the baseline characteristics (author, location, study period, number of patients, age, sex, fracture type, follow-up period), elements for risk of bias evaluation, outcomes, and any statistics of interest. The data were cross-checked, and any discrepancies were resolved through discussions between the two investigators.

Outcomes

The outcomes included (1) postoperative function assessment: CMS or UCLAs; (2) radiographic outcomes: CCD; (3) complications: total complications, implant-related complications (implant mispositioning, loss of reduction, peri-implant fractures, peri-anchor osteolysis, irritation and breakage of the implant), reoperation, and nonunion and delayed union). and (4)surgical outcomes: incision size (cm), operation time (min), blood loss (mL), union time (w).

Risk of bias assessment

Two reviewers (Xiaobo Guo and Hui Peng) independently assessed the risk of methodological bias of the included studies. The Cochrane Risk of Bias tool [27] was employed for RCTs and includes the following domains: random sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. The Risk Of Bias In Nonrandomized Studies—of Interventions (ROBINS-I) tool [28] was used for observational comparative studies, which considers six domains: within-study bias, reporting bias, indirectness, imprecision, heterogeneity, and incoherence. Assessments were displayed graphically with RevMan version 5.4 (Cochrane Collaboration) and the Confidence in Network Meta-Analysis (CINeMA) tool [29, 30]. Differences between the two reviewers were resolved by consensus and discussion with a third author (Hai Dai).

Statistical analysis

NMA was performed according to the current Preferred Reporting Items for Systematic Review and Meta-Analyses Network Meta-Analyses (PRISMA-NMA) guidelines [31]. A network map was created to present the relationships between the different internal fixation methods. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used as summary statistics to present pooled estimates of dichotomous variables (complications), and mean deviations (MDs) and 95% CIs were used to report pooled estimates of continuous outcomes (Constant Murley Score (CMS), University of California at Los Angeles score (UCLAs), and CC distance (CCD), and surgical outcomes). The inconsistency assessment [32] comprised global inconsistency and local inconsistency. Global inconsistency was estimated by a design-by-treatment interaction model, and local inconsistency was estimated by the node-splitting method. P values < 0.05 were indicated statistical significance unless otherwise specified. Sensitivity analysis was performed to assess the transitivity. The surface under the cumulative ranking curve (SUCRA) was used to rank the effectiveness or safety of internal fixation methods by estimating the probability of a method yielding the best fixation. A larger SUCRA was considered a much better fixation. The predictive interval was assessed and graphed to confirm whether relative treatment effects would work in other populations. Network funnel plot and Egger’s test were generated to evaluate potential publication bias. P values < 0.05 were indicated high risk of publication bias. The NMA was conducted in Stata 15.0 (Stata, College Station, Texas, USA.). The confidence for the results comparing different internal fixation methods was estimated with the Confidence in Network Meta-Analysis (CINeMA) tool, a web application that simplifies the assessment of confidence in findings from NMA.

Results

Identification of eligible studies

We found 1046 articles through the electronic database search. After removing duplicate studies, 676 studies underwent title and abstract review. A total of 632 studies were excluded due to being noncomparative studies, paediatric studies, or studies on acromioclavicular joint dislocation, nonunion, or shaft or medial fracture of the clavicle. Forty-four studies underwent full text review and data extraction, and 41 studies [14,15,16, 20, 21, 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68] were included in the network meta-analysis (NMA). The PRISMA flowchart of the study selection procedure is presented in Fig. 1.

Fig. 1
figure 1

Flowchart of the literature selection

Characteristics of the included studies

The baseline characteristics of the included studies are presented in Table 1. Of the 41 included studies, 28 [15, 20, 33,34,35,36, 39, 42, 44,45,46,47,48, 53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68] were from China, 3 [14, 21, 52] were from the USA, 3 [37, 38, 43] were from Germany, 2 [40, 41] were from Finland and 1 each was from Korea [51], Australia [33], Turkey [16], Morocco [49], and the Netherlands [50]. There were 1969 Neer type II (1642/1969, 83.4%; type II B, 709/1969, 36%) and unclear type (type II or type V, 327/1969, 16.6%) distal clavicle fractures that were fixed with HP (hook plate, 923/1969, 46.9%), LCP (locking compression plate, 384/1969, 19.5%), CC (coracoclavicular reconstruction, 255/1969, 13.0%), LCP + CC (combination of locking compression plate and coracoclavicular reconstruction, 260/1969, 13.2%), KWTB (Kirshner wire and tension band, 123/1969, 6.2%), KWTB + CC (combination of Kirshner wire and tension band and coracoclavicular reconstruction, 10/1969, 0.5%), or KW (Kirshner wire, 14/1969, 0.7%). Twelve studies [21, 34, 36, 38, 47, 50, 52, 53, 56, 58, 60, 65] provided data on HP versus LCP (number of patients: 274 vs. 286), 11 studies [20, 35, 40, 44, 48, 52, 58, 59, 62, 63, 67] provided data on HP versus CC (number of patients: 281 vs. 255), 7 studies [33, 42, 43, 51, 64, 66, 68] provided data on HP versus LCP + CC (number of patients: 178 vs. 148), 6 studies [14, 15, 37, 39, 54, 61] provided data on LCP versus LCP + CC (number of patients: 98 vs. 98), 5 studies [45, 46, 49, 57] provided data on HP versus KWTB (number of patients: 190 vs. 108), 1 study [55] provided data on KWTB versus KW (number of patients: 15 vs. 14), and 1 study [16] provided data on LCP + CC versus KWTB + CC (number of patients: 14 vs. 10).The included studies were published from 2002 to 2021, and the research period of the included studies was from 1988 to 2019. The proportion of women ranged from 4.7 to 70.1%. The mean age and postoperative follow-up ranged from 31.7 to 55.2 years and 6 to 76.2 months, respectively.

Table 1 Baseline characteristics of included studies

Risk of bias assessment

Among the 41 studies included in this meta-analysis, one randomized controlled trail (RCT) [45] had a high risk of bias, as evaluated by the Cochrane Risk of Bias tool. All 40 comparative studies [14,15,16, 20, 21, 33,34,35,36,37,38,39,40,41,42,43,44, 46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68] were at high risk of bias, as evaluated by the Risk Of Bias In Non-randomized Studies—of Interventions (ROBINS-I) tool. The results of the evaluation of the exposure to methodological bias for RCTs and nonrandomized studies are shown in Additional file 2: Fig. S1(B, A), respectively. Additional file 2: Fig. S1C shows the average risk of bias contribution for each comparison within the network.

Constant Murley Score (CMS)

The NMA of the CMS comprised 25 studies [15, 16, 20, 37,38,39,40, 42,43,44, 46,47,48,49, 51, 54, 56, 57, 60,61,62, 64,65,66, 68] with 25 direct comparisons of 6 different internal fixation methods (HP, LCP, CC, LCP + CC, KWTB, and KWTB + CC) (Fig. 2A). The network map is shown in Fig. 3A. The results of the NMA are presented in Table 2, which shows that the combinations of LCP and CC, CC, and KWTB + CC were much more effective for UDCFs compared with LCP, followed by HP and KW fixation. LCP + CC fixation had a significantly higher CMSs of 0.60 (95% CI 0.19–1.02), 1.16 (95% CI 0.77–1.55), and 1.88 (95% CI 1.12–2.63) when compared with LCP, HP, and KWTB, respectively, but no measurable difference was present when compared with CC and KWTB + CC. For ranking of the best treatment, LCP + CC fixation was the first, with an SUCRA of 98.6 (Fig. 4A) and a probability of being the best treatment of 93.3%. There was no measurable inconsistency (p = 0.367) within the NMA. In addition, the prediction intervals were assessed and presented with a graph (Additional file 3: Fig. S5A). The funnel plot and Egger's test did not indicate any risk of publication bias (Fig. 5A, P = 0.171). The confidence of most of the comparisons of interest was graded as low (Additional file 4: Table S1).

Fig. 2
figure 2

Forest plots of the meta-analysis of different internal fixation methods for UDCFs. A CMS; B Total complications. 1, HP; 2, LCP; 3, CC; 4, LCP + CC; 5, KWTB; 6, KWTB + CC; 7, KW

Fig. 3
figure 3

Network meta-analysis maps of CMS and total complications. A CMS; B Total complications. Each node represents an intervention, and the size of the node is proportional to the number of patients assigned to the intervention. The lines indicate direct comparisons between nodes, and the size of the line is proportional to the number of trials comparing each pair of nodes

Table 2 League table of different internal fixation comparisons of CMS, UCLAs, and CCD for UDCF
Fig. 4
figure 4

Rankogram of different internal fixation methods for CMS and total complications. A CMS; B Total complications

Fig. 5
figure 5

Network meta-analysis funnel plots for the assessment of publication bias of the included studies. A CMS; B Total complications. A HP, B LCP, C CC, D LCP + CC, E KWTB, F KWTB + CC, G KW

University of California at Los Angeles score (UCLAs)

The NMA of the UCLAs comprised 6 studies [20, 34, 39, 44, 53, 55, 56] with 6 direct comparisons of 4 different internal fixation methods (HP, LCP, CC, and LCP + CC) (Additional file 5: Fig. S2A). The network map is presented in Additional file 6: Fig. S3A. The results of the consistency NMA are presented in Table 2 and indicated that LCP + CC, CC, and LCP were much more effective for UDCFs than HP fixation in terms of the UCLAs. LCP + CC fixation had a significantly higher UCLAs than HP fixation (1.65 (95% CI 0.01–3.29)), but no measurable difference was present when compared with CC and LCP fixation. In the ranking of the best treatment, LCP + CC fixation was first, with a SUCRA of 82.1 (Additional file 7: Fig. S4A) and a probability of being the best treatment of 64.4%. There was no measurable inconsistency (p = 0.96) within the network. In addition, the prediction intervals were assessed and presented with a graph (Additional file 3: Fig. S5B). The funnel plot and Egger's test did not indicate any risk of publication bias (Additional file 8: Fig. S6A, P = 0.563).

Radiographic outcomes

The NMA of the coracoclavicular distance (CCD) comprised 6 studies [37, 39, 42, 61, 64, 68] with 6 direct comparisons of 3 different internal fixation methods (Additional file 5: Fig. S2B). The network map is presented in Additional file 6: Fig. S3B. The results of the consistency NMA are presented in Table 2 and showed no significant difference in CCD among the 3 internal fixation methods. In the ranking of the best treatment, HP was first, with a SUCRA of 93.1 (Additional file 7: Fig. S4B) and a probability of being the best treatment of 89.1% for CCD. There was no measurable inconsistency (p > 0.05) within the network. The predictive intervals were estimated and plotted (Additional file 3: Fig. S5C). The funnel plot and Egger's test did not indicate any risk of publication bias (Additional file 8: Fig. S6B, P = 0.629).

Complications

Total complications and implant-related complications were reported in all 41 studies [14,15,16, 20, 21, 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68], and 45 direct comparisons were synthesized in an NMA of 7 internal fixation methods (HP, LCP, CC, LCP + CC, KWTB, KWTB + CC, and KW) (Fig. 2B and Additional file 5: Fig. S2C). The network map is shown in Fig. 3B and Additional file 6: Fig. S3C. The results of the consistency NMA are presented in Table 3, which showed that LCP + CC, LCP, CC, and KWTB + CC were much safer fixation methods in terms of total complications and implant-related complications than CC, followed by LCP and HP fixation. Compared with HP, KWTB, and KW fixation, LCP + CC fixation had statistically significantly fewer total complications (0.22 (95% CI 0.09–0.51), 0.05 (95% CI 0.01–0.20), and 0.01 (95% CI 0.00–0.11), respectively) and implant-related complications (0.31 (95% CI 0.14–0.70), 0.12 (95% CI 0.03–0.43), and 0.01 (95% CI 0.00–0.20), respectively). There was no measurable difference between LCP + CC and LCP, CC, or KWTB + CC. In the ranking of the best treatment, LCP + CC fixation was first, with an SUCRA of 93.9 (Fig. 4B) and a probability of being the best treatment of 68.8% for total complications, and a SUCRA of 84.5 (Additional file 7: Fig. S4C) and a probability of being the best treatment of 34.5% for implant-related complications. There was no measurable inconsistency (p = 0.770) within the network. In addition, the prediction intervals were assessed and presented with a graph (Additional file 3: Fig. S5D, E). The funnel plot and Egger's test did not indicate any risk of publication bias (Fig. 5B, P = 0.638; Additional file 8: Fig. S6C, P = 0.341). The confidence of the total complications for most of the comparisons of interest was graded as low (Additional file 9: Table S2).

Table 3 League table of different internal fixation comparisons of complications for UDCF

The forest plots of reoperation and nonunion and delayed union are presented in Additional file 5: Fig. S2D, E, and the network maps are presented in Additional file 6: Fig. S3D and E. The results of the consistency NMA are shown in Table 3 and showed no significant difference in nonunion or delayed union among the 6 different internal fixation methods. LCP + CC had a lower reoperation rate than HP, followed by KWTB and KW, and was first, with a SUCRA of 93.9 (Additional file 7: Fig. S4D) and a probability of being the best treatment of 70.4% for reducing the rate of reoperation. In the ranking of the best treatment, LCP + CC was also ranked first, with a SUCRA of 78.2 (Additional file 7: Fig. S4E) and a probability of being the best treatment of 39.5% for reducing the rate of nonunion and delayed union. There was no measurable inconsistency (p = 0.7713) within the network. The predictive interval plots are presented in Additional file 3: Fig. S5F and G. The funnel plot and Egger's test did not show any risk of publication bias (Additional file 8: Fig. S6D, P = 0.306; Additional file 8: Fig. S6G, P = 0.662).

Surgical outcomes

The forest plots of the NMA for surgical outcomes are shown in Additional file 5: Fig. S2F–I, and the network maps are presented in Additional file 6: Fig. S3F–I. The results (Table 4) showed that CC (SUCRA: 100, Additional file 7: Fig. S4F) fixation was associated with a smaller incision than LCP, LCP + CC, and HP and also had less blood loss than HP (Additional file 7: Fig. S4H). LCP (SUCRA: 83.6, Additional file 7: Fig. S4G) fixation had a shorter operative time than CC, but no statistically significant difference was present compared with HP and LCP + CC. LCP + CC (SUCRA: 81.1) had a shorter union time than HP and CC (Additional file 7: Fig. S4I). There was significant measurable inconsistency (p = 0.0084) within the NMA for incision size. The node-splitting analysis revealed inconsistency between HP versus CC (p = 0.019) and LCP versus CC (p = 0.001). The sensitivity analysis confirmed the robustness of the results. There was no measurable inconsistency within the network for the operative time, blood loss, or union time. In addition, the prediction intervals were assessed and presented with a graph (Additional file 3: Fig. S5H–K). The funnel plot and Egger's test did not indicate any risk of publication bias (Additional file 8: Fig. S6F, P = 0.086; 6G, P = 0.346; 6H, P = 0.057; 6I, P = 0.105).

Table 4 League table of different internal fixation comparisons of surgical outcomes for UDCF

To examine the relative effectiveness and safety of different internal fixation methods, cluster ranking was conducted and indicated that LCP + CC appears to display the greatest potential to be the optimum treatment (Fig. 6).

Fig. 6
figure 6

Cluster-rank plot of CMS and total complications for UDCFs

Discussion

To the best of our knowledge, there has been no systematic review or meta-analysis comparing all internal fixation methods (including single internal fixation and combined internal fixation) prior to this review. This systematic review and NMA showed that LCP + CC fixation was associated with better efficacy and fewer complications than any other internal fixation method for UDCFs. On the other hand, HP, KWTB and KW were associated with lower functional scores and a higher risk of complications. The results indicated that LCP + CC had the greatest potential to be the optimum fixation method for patients with UDCFs. Our NMA provides a reference for surgeons when choosing the best internal fixation method for UDCFs.

The CC ligament is one of the important stabilizing structures of the distal clavicle. CC rupture is the main factor in fracture displacement in proximal fractures; therefore, CC reconstruction is very important for fracture reduction and maintenance reduction [69,70,71]. Yagnik et al. [22] reported that arthroscopy-assisted CC reconstruction of UDCFs reduced implant-related complications and the risk of reoperation, with the same good functional outcomes and union rates as LCP and HP fixation. For UDCFs, especially fractures with a comminuted distal fragments, CC fixation that only fixes the proximal end of the fracture is obviously not enough to achieve the standard of fracture healing.

The advantage of LCP is that its lateral section increases the number of locking screws and the angle of fixation of the screws, increasing the grip and resistance to extraction of the distal fracture block and increasing the effectiveness of fixation of the fracture [72]. In contrast to HP, LCP does not invade the subacromial space and the acromioclavicular joint, reducing complications such as osteoarthritis of the acromioclavicular joint, rotator cuff injury, subacromial impingement and osteolysis [51, 56]. The plate requires a smaller incision and does not require a second operation to remove the internal fixation device. KWTB and KW have a higher risk of implant-related complications, such as pin displacement and skin irritation, which increases the risk of infection and increases fracture loss. Compared with HP, LCP showed better recovery of shoulder function and fewer complications related to pain and limited abduction when treating Neer type II DCFs [73]. However, LCP is significantly less effective for fixing unstable fractures than stable fractures. Our results showed that LCP + CC fixation was associated with better efficacy and fewer complications, as well as a shorter incision and less blood loss but a much longer operative time than other internal fixation methods for UDCFs. Biomechanical studies have shown that LCP + CC can achieve greater fracture stability than the fixation method alone [74, 75]. The mechanism may be that CC fixation protects against upward stresses on the proximal clavicle and achieves fracture repositioning and stabilization, thereby reducing the incidence of screw extraction with LCP and internal fixation failure in the distal clavicle. Therefore, the LCP + CC group seemed to have better outcomes (functional and complications) after fracture fixation than the other groups.

The results of the NMA agreed with the results of the direct meta-analysis that LCP + CC appeared to be the best option in terms of postoperative functional scores and complications in UDCFs. Although prediction interval plots from the NMA indicated that the use of LCP + CC may be ineffective in the future compared to other internal fixation methods, this study offers trends in outcomes between the different internal fixation methods.

Limitations

This research has some limitations. There may be too many internal fixation methods for UDCFs and none of them can achieve the good results, only one low-quality RCT (Additional file 2: Fig. S1B) was retrieved and included in this NMA. The results of the NMA were not consistent with the only one RCT compared HP and KWTB, as well as the other comparative studies. The fracture classifications included in the study were not unified, and subgroup analyses could not be performed due to insufficient data. There were related biases, which may have impacted the results of the study. There is a certain degree of bias that affected the results of the study. The follow-up times of the included studies were different, which led to heterogeneity among the studies, and the effect on the research results needs to be discussed. The quality of the studies included in the meta-analysis was not very high, and the reliability of the comprehensive CINeMA evaluation was medium to low. Therefore, a multi-center RCT with appropriate random sequence generation, allocation concealment and blinding were required for the treatment of UDCFs. The fracture types of all included cases must be clarified to conduct a subgroup analysis for different types of fractures; all surgeons need to be trained in the surgical procedure to reduce the bias; blinding must be assessed in measurers and data analysts.

Conclusions

Overall, the results of this study indicate that LCP + CC appears to be the best internal fixation method for UDCF. Limited to the quality and quantity of the included studies, much larger and higher-quality RCTs are required to confirm these conclusions.

Availability of the data and materials

This study does not contain any third-party materials.

Abbreviations

DCF:

Distal clavicle fracture

UDCF:

Unstable distal clavicle fracture

NMA:

Network meta-analysis

HP:

Hook plate

LCP:

Locking compression plate

CC:

Coracoclavicular reconstruction

LCP + CC:

Combination of LCP and CC

KWTB:

Kirshner wire and tension band

KWTB + CC:

Combination of KWTB and CC

KW:

Kirshner wire

CMS:

Constant Murley Score

UCLAs:

University of California at Los Angeles score

CCD:

Coracoclavicular distance

RCTs:

Randomized controlled trials

CINeMA:

The confidence in network meta-analysis

ORs:

Odds ratios

95% CIs:

95% Confidence intervals

MDs:

Mean deviations

SUCRA:

Surface under cumulative ranking curve

References

  1. Nordqvist A, Petersson C. The incidence of fractures of the clavicle. Clin Orthop Relat Res. 1994;300:127–32.

    Google Scholar 

  2. Edwards DJ, Kavanagh TG, Flannery MC. Fractures of the distal clavicle: a case for fixation. Injury. 1992;23(1):44–6.

    CAS  PubMed  Google Scholar 

  3. Neer CS 2nd. Fractures of the distal third of the clavicle. Clin Orthop Relat Res. 1968;58:43–50.

    PubMed  Google Scholar 

  4. Rokito AS, Zuckerman JD, Shaari JM, Eisenberg DP, Cuomo F, Gallagher MA. A comparison of nonoperative and operative treatment of type II distal clavicle fractures. Bull Hosp Jt Dis. 2002;61(1–2):32–9.

    PubMed  Google Scholar 

  5. Hall JA, Schemitsch CE, Vicente MR, Dehghan N, Nauth A, Nowak LL, et al. Operative vs. non-operative treatment of acute displaced distal clavicle fractures: a multicentre randomized controlled trial. J Orthop Trauma. 2021;35(12):660–6.

    PubMed  Google Scholar 

  6. Kim DW, Kim DH, Kim BS, Cho CH. Current concepts for classification and treatment of distal clavicle fractures. Clin Orthop Surg. 2020;12(2):135–44.

    PubMed  PubMed Central  Google Scholar 

  7. Kapicioglu M, Erden T, Bilgin E, Bilsel K. All arthroscopic coracoclavicular button fixation is efficient for Neer type II distal clavicle fractures. Knee Surg Sports Traumatol Arthrosc. 2021;29(7):2064–9.

    PubMed  Google Scholar 

  8. Yagnik GP, Jordan CJ, Narvel RR, Hassan RJ, Porter DA. Distal clavicle fracture repair: clinical outcomes of a surgical technique utilizing a combination of cortical button fixation and coracoclavicular ligament reconstruction. Orthop J Sports Med. 2019;7(9):2325967119867920.

    PubMed  PubMed Central  Google Scholar 

  9. Wu X, Wang G, Xia Q, Rong K, Gan M, Wen G, et al. Digital technology combined with 3D printing to evaluate the matching performance of AO clavicular hook plates. Indian J Orthop. 2020;54(2):141–7.

    PubMed  PubMed Central  Google Scholar 

  10. Kirsch JM, Blum L, Hake ME. Distal clavicle fractures: open reduction and internal fixation with a hook plate. J Orthop Trauma. 2018;32(Suppl 1):S2–3.

    PubMed  Google Scholar 

  11. Andersen JR, Willis MP, Nelson R, Mighell MA. Precontoured superior locked plating of distal clavicle fractures: a new strategy. Clin Orthop Relat Res. 2011;469(12):3344–50.

    PubMed  PubMed Central  Google Scholar 

  12. Chun JM, Kim SY. Modified tension band fixation for UDCF. J Trauma. 2011;70(5):E88-92.

    PubMed  Google Scholar 

  13. Wu CC. Tension band wiring versus Knowles pinning for non-union of type-2 distal clavicle fractures. J Orthop Surg (Hong Kong). 2012;20(3):297–301.

    Google Scholar 

  14. Salazar BP, Chen MJ, Bishop JA, Gardner MJ. Outcomes after locking plate fixation of distal clavicle fractures with and without coracoclavicular ligament augmentation. Eur J Orthop Surg Traumatol. 2021;31(3):473–9.

    PubMed  Google Scholar 

  15. Xu H, Chen WJ, Zhi XC, Chen SC. Comparison of the efficacy of a distal clavicular locking plate with and without a suture anchor in the treatment of Neer IIb distal clavicle fractures. BMC Musculoskelet Disord. 2019;20(1):503.

    PubMed  PubMed Central  Google Scholar 

  16. Seyhan M, Kocaoglu B, Kiyak G, Gereli A, Turkmen M. Anatomic locking plate and coracoclavicular stabilization with suture endo-button technique is superior in the treatment of Neer Type II distal clavicle fractures. Eur J Orthop Surg Traumatol. 2015;25(5):827–32.

    PubMed  Google Scholar 

  17. Muramatsu K, Shigetomi M, Matsunaga T, Murata Y, Taguchi T. Use of the AO hook-plate for treatment of unstable fractures of the distal clavicle. Arch Orthop Trauma Surg. 2007;127(3):191–4.

    CAS  PubMed  Google Scholar 

  18. Lopiz Y, Checa P, García-Fernández C, Valle J, Vega ML, Marco F. Complications with the clavicle hook plate after fixation of Neer type II clavicle fractures. Int Orthop. 2019;43(7):1701–8.

    PubMed  Google Scholar 

  19. Asadollahi S, Bucknill A. Hook plate fixation for acute unstable distal clavicle fracture: a systematic review and meta-analysis. J Orthop Trauma. 2019;33(8):417–22.

    PubMed  Google Scholar 

  20. Wu C, Xia YQ, Wang JJ, Liu RG, Fan JN. TightRope system versus clavicular hook plate in the treatment of Neer type II distal clavicle fractures using arthroscopy. Chin J Tissue Eng Res. 2019;23(32):5117–25.

    Google Scholar 

  21. Chen MJ, DeBaun MR, Salazar BP, Lai C, Bishop JA, Gardner MJ. Hook versus locking plate fixation for Neer type-II and type-V distal clavicle fractures: a retrospective cohort study. Eur J Orthop Surg Traumatol. 2020;30(6):1027–31.

    PubMed  Google Scholar 

  22. Yagnik GP, Seiler JR, Vargas LA, Saxena A, Narvel RI, Hassan R. Outcomes of arthroscopic fixation of UDCF: a systematic review. Orthop J Sports Med. 2021. https://doi.org/10.1177/23259671211001773.

    Article  PubMed  PubMed Central  Google Scholar 

  23. Wei Y, Zhou J, Chen W, Li B, Huang J, Wang J, et al. Treatment of distal clavicle fractures and selection of implants [Chinese]. Chin J Tissue Eng Res. 2021;25(30):4877–82.

    Google Scholar 

  24. Skou ST, Juhl CB, Hare KB, Lohmander LS, Roos EM. Surgical or non-surgical treatment of traumatic skeletal fractures in adults: systematic review and meta-analysis of benefits and harms. Syst Rev. 2020;9(1):179.

    PubMed  PubMed Central  Google Scholar 

  25. Boonard M, Sumanont S, Arirachakaran A, Sikarinkul E, Ratanapongpean P, Kanchanatawan W, et al. Fixation method for treatment of unstable distal clavicle fracture: systematic review and network meta-analysis. Eur J Orthop Surg Traumatol. 2018;28(6):1065–78.

    PubMed  Google Scholar 

  26. Oh JH, Kim SH, Lee JH, Shin SH, Gong HS. Treatment of distal clavicle fracture: a systematic review of treatment modalities in 425 fractures. Arch Orthop Trauma Surg. 2011;131(4):525–33.

    PubMed  Google Scholar 

  27. Higgins JP, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD, et al. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ. 2011;343:d5928.

    PubMed  PubMed Central  Google Scholar 

  28. Sterne JA, Hernán MA, Reeves BC, Savović J, Berkman ND, Viswanathan M, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016;355:i4919.

    PubMed  PubMed Central  Google Scholar 

  29. Nikolakopoulou A, Higgins JPT, Papakonstantinou T, Chaimani A, Del Giovane C, Egger M, et al. CINeMA: An approach for assessing confidence in the results of a network meta-analysis. PLoS Med. 2020;17(4):e1003082.

    PubMed  PubMed Central  Google Scholar 

  30. Papakonstantinou T, Nikolakopoulou A, Higgins JPT, Egger M, Salanti G. CINeMA: software for semiautomated assessment of the confidence in the results of network meta-analysis. Campbell Syst Rev. 2020;16(1):e1080.

    Google Scholar 

  31. Hutton B, Catalá-López F, Moher D. The PRISMA statement extension for systematic reviews incorporating network meta-analysis: PRISMA-NMA. Med Clin (Barc). 2016;147(6):262–6.

    Google Scholar 

  32. Shim S, Yoon BH, Shin IS, Bae JM. Network meta-analysis: application and practice using Stata. Epidemiol Health. 2017;39:e2017047.

    PubMed  PubMed Central  Google Scholar 

  33. Bhatia DN, Page RS. Surgical treatment of lateral clavicle fractures associated with complete coracoclavicular ligament disruption: clinico-radiological outcomes of acromioclavicular joint sparing and spanning implants. Int J Shoulder Surg. 2012;6(4):116–20.

    PubMed  PubMed Central  Google Scholar 

  34. Cai T, Chen Y. Two different kinds of fixation materials in repair of distal clavicle fracture: stability of reconstruction. Chin J Tissue Eng Res. 2014;18(26):4136–41.

    Google Scholar 

  35. Chen CY, Yang SW, Lin KY, Lin KC, Tarng YW, Renn JH, et al. Comparison of single coracoclavicular suture fixation and hook plate for the treatment of acute UDCF. J Orthop Surg Res. 2014;9:42.

    PubMed  PubMed Central  Google Scholar 

  36. Dai LM, Xie J, Nian SS, Cao LH, Ma YH, Su JC. Clavicule hook plate and locking fixation for treatment of neer typellfractures of clavicle lateral end: a comparison of clinical efficacies. Acad J Second Mil Univ. 2011;32(3):347–8.

    Google Scholar 

  37. Dey Hazra RO, Blach RM, Ellwein A, Lill H, Warnhoff M, Jensen G. Additional coracoclavicular augmentation reduces revision rates in the treatment of lateral clavicle fractures as compared to angle-stable plate osteosynthesis alone. Arch Orthop Trauma Surg. 2021. https://doi.org/10.1007/s00402-021-03893-1.

    Article  PubMed  Google Scholar 

  38. Erdle B, Izadpanah K, Jaeger M, Jensen P, Konstantinidis L, Zwingmann J, et al. Comparative analysis of locking plate versus hook plate osteosynthesis of Neer type IIB lateral clavicle fractures. Arch Orthop Trauma Surg. 2017;137(5):651–62.

    PubMed  Google Scholar 

  39. Fan J, Zhang Y, Huang Q, Jiang X, He L. Comparison of treatment of acute UDCF using anatomical locking plates with versus without additional suture anchor fixation. Med Sci Monit. 2017;23:5455–61.

    PubMed  PubMed Central  Google Scholar 

  40. Flinkkilä T, Heikkilä A, Sirniö K, Pakarinen H. TightRope versus clavicular hook plate fixation for unstable distal clavicular fractures. Eur J Orthop Surg Traumatol. 2015;25(3):465–9.

    PubMed  Google Scholar 

  41. Flinkkilä T, Ristiniemi J, Hyvönen P, Hämäläinen M. Surgical treatment of unstable fractures of the distal clavicle: a comparative study of Kirschner wire and clavicular hook plate fixation. Acta Orthop Scand. 2002;73(1):50–3.

    PubMed  Google Scholar 

  42. Gao ZY, Ma YM, Zun YC, Han L. Comparison the effects between anatomical locked plate in combination with coracoclavicular ligament reconstruction and clavicular hook plate for the treatment of Neer II b distal clavicle fractures. Zhongguo Gu Shang. 2015;28(2):112–6.

    PubMed  Google Scholar 

  43. Helfen T, Siebenbürger G, Haasters F, Böcker W, Ockert B. Concomitant glenohumeral injuries in Neer type II distal clavicle fractures. BMC Musculoskelet Disord. 2018;19(1):24.

    PubMed  PubMed Central  Google Scholar 

  44. Hsu KH, Tzeng YH, Chang MC, Chiang CC. Comparing the coracoclavicular loop technique with a hook plate for the treatment of distal clavicle fractures. J Shoulder Elbow Surg. 2018;27(2):224–30.

    PubMed  Google Scholar 

  45. Hsu TL, Hsu SK, Chen HM, Wang ST. Comparison of hook plate and tension band wire in the treatment of distal clavicle fractures. Orthopedics. 2010;33(12):879.

    PubMed  Google Scholar 

  46. Lee YS, Lau MJ, Tseng YC, Chen WC, Kao HY, Wei JD. Comparison of the efficacy of hook plate versus tension band wire in the treatment of unstable fractures of the distal clavicle. Int Orthop. 2009;33(5):1401–5.

    PubMed  Google Scholar 

  47. Li L, Wu HX, Jiang PC, Han XC, Chen SY, Yu XZ. Comparison of four different internal fixation methods in the treatment of distal clavicle fractures. Exp Ther Med. 2020;19(1):451–8.

    PubMed  Google Scholar 

  48. Lu Z, Qiu XD, Ren YC. Treatment of distal clavicle type II fracture: suture anchor versus clavicular hook plate. Zhejiang Da Xue Xue Bao Yi Xue Ban. 2014;43(5):577–82.

    PubMed  Google Scholar 

  49. Mechchat A, Elidrissi M, Shimi M, Elibrahimi A, Elmrini A. Neer type II distal clavicle fractures: hook plate versus transacromial pin. Pan Afr Med J. 2015;20:105.

    PubMed  PubMed Central  Google Scholar 

  50. Ochen Y, Frima H, Houwert RM, Heng M, van Heijl M, Verleisdonk EJMM, et al. Surgical treatment of Neer type II and type V lateral clavicular fractures: comparison of hook plate versus superior plate with lateral extension: a retrospective cohort study. Eur J Orthop Surg Traumatol. 2019;29(5):989–97.

    PubMed  PubMed Central  Google Scholar 

  51. Seo JB, Kwak KY, Yoo JS. Comparative analysis of a locking plate with an all-suture anchor versus hook plate fixation of Neer IIb distal clavicle fractures. J Orthop Surg (Hong Kong). 2020;28(3):2309499020962260.

    Google Scholar 

  52. Singh A, Schultzel M, Fleming JF, Navarro RA. Complications after surgical treatment of distal clavicle fractures. Orthop Traumatol Surg Res. 2019;105(5):853–9.

    PubMed  Google Scholar 

  53. Tan HL, Zhao JK, Qian C, Shi Y, Zhou Q. Clinical results of treatment using a clavicular hook plate versus a T-plate in neer type II distal clavicle fractures. Orthopedics. 2012;35(8):e1191–7.

    PubMed  Google Scholar 

  54. Tang H, Yin Y, Han Q, Xu X, Li Y. Effectiveness of anatomical locking plate internal fixation combined with coracoclavicular ligament reconstruction for Neer type II b distal clavicle fractures. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2018;32(9):1181–6.

    PubMed  Google Scholar 

  55. Tsuei YC, Au MK, Chu W. Comparison of clinical results of surgical treatment for UDCF by transacromial pins with and without tension band wire. J Chin Med Assoc. 2010;73(12):638–43.

    PubMed  Google Scholar 

  56. Wang HK, Liang LS, He RG, Su YB, Mao P, Hu JZ. Comparative analysis of locking plates versus hook plates in the treatment of Neer type II distal clavicle fractures. J Int Med Res. 2020;48(4):300060520918060.

    PubMed  Google Scholar 

  57. Wu K, Chang CH, Yang RS. Comparing hook plates and Kirschner tension band wiring for unstable lateral clavicle fractures. Orthopedics. 2011;34(11):e718–23.

    PubMed  Google Scholar 

  58. Xiong J, Chen JH, Dang Y, Zhang DY, Fu ZG, Zhang PX. Treatment of UDCF (Neer type II): a comparison of three internal fixation methods. J Int Med Res. 2018;46(11):4678–83.

    PubMed  PubMed Central  Google Scholar 

  59. Xu Q, Wang QM, He JF, Sun WG, Chen XW. Comparison of double titanium plate and clavicular hook plate for the treatment of Neer II distal clavicular fracture. Zhongguo Gu Shang. 2016;29(12):1125–9.

    PubMed  Google Scholar 

  60. Zhang CL, Huang JW, Luo Y, Sun H. Comparison of the efficacy of a distal clavicular locking plate versus a clavicular hook plate in the treatment of UDCF and a systematic literature review. Int Orthop. 2014;38(7):1461–8.

    PubMed  PubMed Central  Google Scholar 

  61. Zhang YF, Mi M, Zhang J, Guo Q, Gong MQ, Huang Q, et al. Case-control study on single locking plate and locking plate with suture anchors for the treatment of UDCF. Zhongguo Gu Shang. 2019;32(1):11–6.

    PubMed  Google Scholar 

  62. Xiang YL, Li YH, Lin ZR. Double butons combined with suture versus hook plate for Neer type IIB distal clavicle fractures. Orthop J China. 2018;26(16):1457–63.

    Google Scholar 

  63. Wu BY, Li CJ, Zhou XX, Mou XS, Xie Y, Zhang XH. Clinical comparison of double Endobuton and clavicular hook plate for the treatment of Neer II distal clavicle fracture. Orthop J China. 2010;22:1853–7.

    Google Scholar 

  64. Zeng JC, Zhu LF, Qian XF, Yan ZJ. Hook plate versus anatomic locking plate combined with coracoclavicular suture fixation for UDCF. Orthop J China. 2018;26(24):2225–9.

    Google Scholar 

  65. Zhu T, Fu ZY, Hu XP, Wu YJ. Comparison of the effect of distal radius T-shaped locking plate and clavicle hook plate in the treatment of NeerII type distal clavicle fractures. Chin J Orthop Trauma. 2014;16(1):76–8.

    Google Scholar 

  66. Lin SF, Yao XD, Dai ZS, Ye H, Yao JZ, Xie JJ. Anatomical locking compression plate augmented with anchor nail versus calvicular hook plate for Neer IIb distal calvicular fractures. Chin J Orthop Trauma. 2017;19(1):41–6.

    Google Scholar 

  67. Wang PY, Ju JL, Cai JH, Shen MR, Zhang HY, Wang P. The application of double Endobutton plate technology for Neer II Type B distal clavicle fracture under arthroscopy. Guangdong Med J. 2019;40(22):3162–7.

    Google Scholar 

  68. Hu XC, Huang CM, Fan HQ, Zhang SZ, Fu YP, Dong HX, Gan ZY, Li HD. Plate combined with cerclage cable versus hook plate for Neer type II distal clavicular fractures. Orthop J China. 2019;27(22):2046–9.

    Google Scholar 

  69. Furuhata R, Matsumura N, Udagawa K, Oki S, Morioka H. Residual coracoclavicular separation after plate fixation for distal clavicle fractures: comparison between fracture patterns. JSES Int. 2021;5(5):840–5.

    PubMed  PubMed Central  Google Scholar 

  70. Malik SS, Tahir M, Malik S, Kwapisz A, Jordan RW. Arthroscopically assisted coraco-clavicular ligament reconstruction in treatment of acute displaced distal clavicle fractures provides good to excellent shoulder function despite low union rates and high complication rates: a systematic review. Arthroscopy. 2021. https://doi.org/10.1016/j.arthro.2021.06.034.

    Article  PubMed  Google Scholar 

  71. Perskin CR, Tejwani NC, Jazrawi LM, Leucht P, Egol KA. Clinical outcomes of a combined osteoligamentous reconstruction technique of Neer Type IIB distal clavicle fractures. J Orthop. 2021;25:134–9.

    PubMed  PubMed Central  Google Scholar 

  72. Frima H, Houwert RM, Sommer C. Displaced medial clavicle fractures: operative treatment with locking compression plate fixation. Eur J Trauma Emerg Surg. 2020;46(1):207–13.

    PubMed  Google Scholar 

  73. Li L, Li TY, Jiang P, Lin G, Wu H, Han X, et al. Clavicle hook plate versus distal clavicle locking plate for Neer type II distal clavicle fractures. J Orthop Surg Res. 2019;14(1):472.

    PubMed  PubMed Central  Google Scholar 

  74. Rieser GR, Edwards K, Gould GC, Markert RJ, Goswami T, Rubino LJ. Distal-third clavicle fracture fixation: a biomechanical evaluation of fixation. J Shoulder Elbow Surg. 2013;22(6):848–55.

    PubMed  Google Scholar 

  75. Yagnik GP, Brady PC, Zimmerman JP, Jordan CJ, Porter DA. A biomechanical comparison of new techniques for distal clavicular fracture repair versus locked plating. J Shoulder Elbow Surg. 2019;28(5):982–8.

    PubMed  Google Scholar 

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Authors and Affiliations

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Contributions

YX: literature search, data extraction, statistical analyses, writing; XG: data extraction, methodological quality assessment, revision; HP: methodological quality assessment; HD: literature search, methodological quality assessment; ZH: supervision, revision, final approval; JZ: supervision, revision, final approval. All authors read and approved the final manuscript.

Corresponding authors

Correspondence to Zonggui Huang or Jinmin Zhao.

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Supplementary Information

Additional file 1:

Appendix 1. Search strategies for electronic databases.

Additional file 2: Figure S1.

Risk of bias assessment for the included studies. A Risk of bias summary for the nonrandomized studies. B Risk of bias summary for the randomized studies. C The average risk of bias contribution for each comparison within the network.

Additional file 3: Fig. S5.

Predictive interval plots of the postoperative function assessment, radiographic outcome, complications and surgical outcomes between the comparisons. A CMS; B UCLAs; CCCD; D Total complications; E Implant-related complications; F Reoperation; G Nonunion and delayed union; H Incision; I Operative time; J Blood loss; KUnion time.

Additional file 4: Table S1.

The confidence rating for the CMS of different internal fixation comparisons for UDCFs.

Additional file 5: Fig. S2.

Forest plots of the meta-analysis of different internal fixation methods for UDCFs. A. UCLAs; B CCD; CImplant-related complications; D Reoperation; E Nonunion and delayed union; F Incision; G Operative time; H Blood loss; I Union time. 1, HP; 2, LCP; 3, CC; 4, LCP + CC; 5, KWTB; 6, KWTB + CC; 7, KW.

Additional file 6: Fig. S3.

Network meta-analysis maps of the outcomes. A UCLAs; B CCD; C Implant-related complications; D Reoperation; E Nonunion and delayed union; F Incision; G Operative time; H Blood loss; I Union time. Each node represents an intervention, and the size of the node is proportional to the number of patients assigned to the intervention. The lines indicate direct comparisons between nodes, and the size of the line is proportional to the number of trials comparing each pair of nodes.

Additional file 7: Fig. S4.

Rankogram of different internal fixation methods for outcomes. A. UCLAs; B CCD; C Implant-related complications; D Reoperation; E Nonunion and delayed union; F Incision; G Operative time; H Blood loss; I Union time.

Additional file 8: Fig. S6.

Network meta-analysis funnel plots for the assessment of publication bias of the included studies. A UCLAs; B CCD; C Implant-related complications; D Reoperation; E Nonunion and delayed union; FIncision; G Operative time; H Blood loss; I Union time. A, C–H A: HP, B: LCP, C: CC, D: LCP + CC, E: KWTB, F: KWTB + CC, G: KW; B: A: HP, B: LCP, C: LCP + CC; I A: HP, B: LCP, C: CC, D: LCP + CC, E: KWTB, F: KW.

Additional file 9: Table S2.

The confidence rating for total complications of different internal fixation comparisons for UDCFs.

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Xu, Y., Guo, X., Peng, H. et al. Different internal fixation methods for unstable distal clavicle fractures in adults: a systematic review and network meta-analysis. J Orthop Surg Res 17, 43 (2022). https://doi.org/10.1186/s13018-021-02904-6

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