Comparison of the arthroscopic and open surgery for the treatment of acute high-grade acromioclavicular joint dislocation using suture button: a systematic review and meta-analysis

Abstract

Purpose

• To conduct a meta-analysis of clinical studies evaluating the efficacy and safety of arthroscopic and open surgery for the treatment of acute high-grade acromioclavicular joint (ACJ) dislocation using a suture button.

Methods

• The review process was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent reviewers conducted the literature searches based on preferred reporting items from systematic reviews and meta-analyses. PubMed, EMBASE, Web of Science, and the Cochrane Library were searched for studies comparing arthroscopic and open surgery for the treatment of acute high-grade ACJ dislocation using a suture button. Constant score, visual analog scale, coracoclavicular distance, acromioclavicular distance, operation time, and occurrence of complications were analyzed.

Results

• Five studies comprising a total of 198 patients were included in this study. The findings revealed that, in comparison to open fixation, arthroscopic fixation resulted in longer surgical durations. However, there were no significant differences between the two techniques in terms of constant score, visual analog scale, coracoclavicular distance, acromioclavicular distance, or the occurrence of complications.

Conclusions

• Based on current evidence, arthroscopic fixation demonstrates comparable postoperative outcomes to open fixation, albeit with longer surgical durations. With ongoing technological advancements and refinement of surgical techniques, the efficiency and accessibility of arthroscopy are expected to improve, potentially solidifying its role as a superior choice in the future.

Introduction

Shoulder dislocation is a prevalent traumatic condition in shoulder injuries, with up to 50% of shoulder traumas affecting the acromioclavicular joint (ACJ) (1). Acute ACJ injuries are typically defined as those occurring within the first 3 weeks following trauma, a timeframe during which the integrity of the surrounding soft tissues and ligaments may still allow for effective reduction and stabilization (2, 3). Over time, various surgical methods have been developed to stabilize acute ACJ dislocations. Among these, minimally invasive techniques utilizing a suture button have emerged as the preferred approach for acute ACJ injuries, while internal fixation with a hook plate is often reserved for specific cases, such as revision surgeries or situations where other fixation methods are not feasible. It is important to note that acute injuries are typically defined as those occurring within 3 weeks of the traumatic event (4). In the realm of minimally invasive techniques, the focus has predominantly been on two coracoclavicular (CC) stabilization methods: single- or double-tunnel techniques. In cases of high-grade ACJ dislocations, both approaches can be augmented with horizontal stabilization through an acromioclavicular cerclage (5, 6). The primary point of differentiation between these minimally invasive techniques lies in their approach: arthroscopic versus mini-open. While both methods have demonstrated favorable outcomes ranging from good to excellent, there remains a paucity of direct comparative analyses. The arthroscopic approach holds potential advantages in identifying intra-articular pathologies. Conversely, the mini-open technique offers simplicity, making it accessible to trauma surgeons without specialized arthroscopic expertise or equipment. Existing research presents conflicting conclusions regarding the effectiveness of these two surgical approaches. While Behrens et al. and Abdelrahman et al. found no disparity in functional scores between the groups (7, 8), Pan et al.’s study revealed that postoperative constant score (CS) ratings were higher in the arthroscopic group compared to the open group (9). Therefore, a definitive consensus on current efficacy remains elusive. This study aims to conduct a comprehensive analysis of the existing literature to evaluate the clinical outcomes of arthroscopic versus open surgery for treating acute high-grade ACJ dislocation using a suture button.

Methods

The study conforms to the principles outlined in the Handbook of the Cochrane Collaboration (10), along with the guidelines established by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement (11). The protocol for this meta-analysis was registered on PROSPERO (Registration No: CRD42024530123).

Inclusion criteria

1. Studies with full text available that directly compare the efficacy of arthroscopic versus open surgery for treating acute high-grade ACJ dislocation using the suture button technique.

2. Inclusion of patients with acute Rockwood type ≥ III dislocation.

3. Evaluation of functional outcomes utilizing measures such as the CS, visual analog scale (VAS), coracoclavicular distance (CCD), acromioclavicular distance (ACD), operation time, or incidence of complications.

Exclusion criteria

1. Studies that consist of letters, case reports, reviews, animal trials, or republished studies.

2. Articles lacking complete or essential data.

3. Studies involving patients undergoing revision procedures or with a loss to follow-up exceeding 20%.

4. Cases with chronic ACJ dislocation (>6 weeks after trauma).

5. Cases diagnosed radiographically as ACJ injuries of Rockwood grade I–II.

Outcomes

The primary outcome was the validated outcome score, including CS and VAS. Secondary outcomes were operation time, CCD, ACD, and incidence of complications.

Search strategy

Two authors independently searched PubMed, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials for studies from inception to March 2024. The search terms included ‘open’, ‘suture button’, ‘arthroscopic’, and ‘acromioclavicular dislocations’, with no language restrictions applied. To reduce bias, the reviewers conducted blinded evaluations independently.

Study selection

After removing duplicates, two researchers independently screened titles and abstracts, applying inclusion and exclusion criteria. Full texts were reviewed for eligible studies. Disagreements were resolved through group discussion, with the senior researcher making the final decision.

Data collection process

Two investigators independently extracted data from the selected studies using a standardized form. Extracted information included the author, year, country, study type, sample size, age, and outcomes. Disagreements were resolved by consensus.

Assessment of risk of bias and quality of evidence

Two researchers independently assessed the quality of RCTs using Cochrane risk-of-bias criteria and non-RCTs with the Newcastle–Ottawa Scale (NOS) (12, 13). The NOS checklist evaluates selection, comparability, and exposure or outcome, grading studies from 0 to 9. Scores of 7–9, 5–6, 4, and 0–3 indicate very good, good, satisfactory, and unsatisfactory quality, respectively, with scores of 6 or higher considered high quality. Researchers ensured blinding to authors’ names, institutions, journals, and study results during bias assessment. Disagreements were resolved by consensus.

Statistical analysis

Meta-analysis was conducted using Stata software (version 17; StataCorp, USA, 2021), with heterogeneity assessed via the Q test and I² values. A random-effects model was applied, calculating odds ratios (OR) with 95% confidence intervals (CI) for dichotomous outcomes and weighted mean difference (WMD) with 95% CIs for continuous outcomes based on mean, standard deviation (SD), and sample size. Sensitivity analysis excluded the most significant trial and studies with a high risk of bias.

Results

A total of 703 relevant studies were identified, and after removing 330 duplicates, 11 potentially suitable full-text articles were obtained based on title and abstract screening. Following a thorough review of the full texts, six articles were excluded. Among these, three studies did not involve open or arthroscopic fixation, one study included patients with subacute and chronic ACJ, one study employed tendon transplantation, and one study encompassed multiple surgical techniques, rendering it difficult to extract our outcome measures. Ultimately, five studies involving 198 patients were included in our meta-analysis (7, 8, 14, 15, 16). These comprised two RCTs and three cohort studies. The search flow diagram is showed in Fig. 1.

Figure 1.

Flow diagram for search and selection of included studies.

Characteristics of included studies

The basic characteristics of the included studies are shown in Table 1. These studies were published between 2014 and 2024. Two studies originated from Germany, one from the United Arab Emirates, one from Italy, and one from China. Pan et al. exhibited some bias overall due to unclear allocation and performance bias (16). Abdelrahman et al. demonstrated high bias overall as attrition bias (8). All nonrandomized studies received NOS of six points or higher, indicating high-quality research.

Table 1.

Characteristics of included studies.

	Abdelrahman et al. (8)	Behrens et al. (7)	Faggiani et al. (15)	Koch et al. (14)	Pan et al. (16)
Study design	RCT	RCS	RCS	RCS	RCT
Country	UAE	Germany	Italy	Germany	China
Rockwood type	III & IV	≥ IIIb	III & IV	V	III
Study duration	2011–2016	2018–2020	2012–2015	NA	2010–2013
Minimum FU (months)	24	24	6	NA	14
Suture button use
Arthroscopic	TightRope	DogBone	DogBone	TightRope	Endobutton
Open	TightRope	Endobutton	MINAR system	TightRope	Endobutton
Age (years)			36.94 (19–54)
Arthroscopic	31.0 ± 7.87	41.2 ± 15.4		33 ± 10	32.8 ± 11.3
Open	28.83 ± 7.32	41.3 ± 14.8		35 ± 10	34.9 ± 11.9
Subjects, n
Arthroscopic	24	14	8	19	31
Open	22	16	8	26	30
Outcomes	CS, VAS, CCD, complication, operation time, cost	CS, VAS, CCD, complication, ROM	CS, SPORTS	CS, SST, TS, muscle strength, CCD, complication	CCD, CS, complication
Risk of bias*	High	9	7	7	Some

^*Assessment tool for RCTs or NOS (observational).

FU, follow-up; RCT, randomized control trial; RCS, retrospective cohort study; SST, simple shoulder test; TS, Taft Score; SPORTS, subjective patient outcome for return to sports; CCD, coracoclavicular distance; CS, constant score; VAS, visual analog scale; ROM, range of motion; NOS, Newcastle–Ottawa scale; NA, not applicable.

Constant score

All five studies included in the analysis examined the CS (7, 8, 14, 15, 16). Faggiani et al. and Pan et al. reported that the arthroscopic group exhibited significantly higher CS scores than the open group (15, 16). Conversely, the remaining three studies found no significant differences between the two groups. Since Faggiani et al. only provided mean values, their results could not be integrated. Upon pooling the data, no statistically significant difference in CS was observed between the arthroscopic and open surgery groups (WMD: 2.78, 95% CI: −3.46 to 9.01, I² = 93.3%, P = 0.382; Fig. 2). After excluding the study by Pan et al., the heterogeneity of the combined results became 0%.

Figure 2.

Forest plot for CS (7, 8, 14, 15, 16).

VAS

Two studies reported results for the VAS (7, 8). The combined results indicated no difference in postoperative VAS scores between the arthroscopic and open surgery groups (WMD: −0.47, 95% CI: −1.78 to 0.84, I² = 0%, P = 0.481; Fig. 3).

Figure 3.

Forest plot for VAS (7, 8).

CCD

Four studies reported postoperative values for the CCD (7, 8, 14, 16). Koch et al. (14) conducted their measurements under a 5 kg weight-bearing condition, whereas the other studies did not specify whether measurements were performed with or without weight. In addition, the study by Behrens et al. (7) measured the CCD values using ultrasound, which is why this study was not included in the forest plot. The pooled results also demonstrated that there was no statistically significant difference in CCD between the arthroscopic and open surgery groups (WMD: 0.20, 95% CI: −1.46 to 1.86, I² = 85.5%, P = 0.810; Fig. 4). After excluding the study by Pan et al., the heterogeneity significantly decreased.

Figure 4.

Forest plot for coracoclavicular distance (8, 14, 16).

Operation time

Two studies provided data on operation time (7, 8). The combined results revealed that the arthroscopic group had longer surgical times compared to the open surgery group (WMD: 22.35, 95% CI: 8.45–36.25, I² = 57.2%, P = 0.002; Fig. 5).

Figure 5.

Forest plot for operation time (7, 8).

Complications

Three studies reported complications (8, 14, 16). Notably, Pan et al. documented postoperative shoulder joint pain as a complication. Our study primarily addressed risks such as wound complications, secondary fractures, joint stiffness, hardware failure, and recurrent dislocations. Given the nonspecific nature of joint pain, we opted not to amalgamate Pan et al.’s complication data with that of other studies. The pooled results revealed no significant difference in complication occurrence between the two groups (OR: 1.11, 95% CI: 0.19–6.60, I² = 58.3%, P = 0.909; Fig. 6).

Figure 6.

Forest plot for complication (8, 14).

ACD

Three studies reported ACD. Among them, Koch et al. conducted their measurements under a 5 kg weight-bearing condition, while the other studies did not specify whether weight-bearing was applied. In addition, the study by Behrens et al. measured ACD using ultrasound, which is why this study was not included in the forest plot. The pooled results indicated no significant difference in ACD values between the two groups (WMD: 1.07, 95% CI: −1.07 to 3.21, I² = 85.1%, P = 0.326; Fig. 7).

Figure 7.

Forest plot for acromioclavicular distance (14, 16).

Risk of bias

As fewer than ten trials were included, no publication bias assessment was performed by funnel plots.

Discussion

In the meta-analysis concerning ACJ treatment, the primary focus lies on comparing hook plate and suture button fixation against conservative and surgical interventions (9, 17, 18, 19, 20). However, there is currently no meta-analysis available for comparing arthroscopic suture button fixation with open suture button fixation. Our analysis reveals that, in comparison to open surgery, arthroscopic surgery for acute ACJ dislocation necessitates a lengthier operation time. Nonetheless, no discernible discrepancies between the two groups were observed in terms of postoperative outcomes such as CS, VAS, CCD, and complications. Significant heterogeneity was noted in CS and CCD, with sensitivity analysis attributing this mainly to the study by Pan et al. (16). It is plausible that Pan et al.’s study exclusively enrolled patients with type 3 ACJ dislocation, where the advantages of arthroscopic surgery might be more pronounced for milder cases. However, upon excluding Pan et al.'s data, the pooled results remained consistent with the previous findings, affirming the robustness of our conclusions.

Arthroscopic surgery demands additional time for preparatory tasks, including precise positioning and thorough cleansing of the surgical site, ensuring optimal visualization and maneuvering space. Due to the constrained surgical field of view, addressing challenges or intricate scenarios encountered during the procedure may necessitate extended time. Conversely, direct open reduction surgery may prove relatively straightforward and expeditious, benefiting from an intuitive and unimpeded surgical field and simpler procedural steps. The operative time for arthroscopic surgery is inherently more dependent on the surgeon’s technical skills and experience compared to open procedures. Arthroscopic techniques require a higher degree of precision, dexterity, and familiarity with the equipment, leading to a steeper learning curve. In contrast, open procedures are often more straightforward and less technique-sensitive, resulting in more consistent operative times regardless of the surgeon’s experience level. This dependency on skill level introduces a significant risk of bias when comparing operative times between the two techniques. Studies involving surgeons with varying levels of arthroscopic expertise may overestimate the operative duration of arthroscopic procedures, especially when less experienced surgeons are included. This variability in surgical time reflects the influence of surgeon-specific factors rather than the inherent characteristics of the technique itself. However, arthroscopic surgery offers a distinct advantage in that it allows for the direct visualization and management of intra-articular pathologies, which may coexist with ACJ injuries. This capability provides a more comprehensive approach to treating associated shoulder conditions, such as rotator cuff injuries or labral tears, which cannot be effectively addressed with open techniques. Consequently, this may yield a comparatively shorter surgical duration for open reduction with hook plate. It is anticipated that ongoing advancements in arthroscopic techniques and refinements in surgical protocols will further streamline the surgical duration for arthroscopic CC fixation. However, it is important to note that for ACJ injuries, it is inherently challenging to demonstrate significant differences in clinical outcomes among different surgical techniques. This limitation is partly due to the overlapping range of clinical outcomes, such as pain relief, functional recovery, and complication rates, which often fail to exhibit substantial variations across different surgical modalities. In addition, the small effect sizes and heterogeneity in patient populations, injury severities, and surgical expertise across studies contribute to this difficulty. Moreover, nonoperative treatment remains a viable option for specific types of ACJ dislocations, particularly low-grade injuries or in patients with low functional demands. While surgical techniques may offer advantages such as superior reduction and potentially better cosmetic outcomes, nonoperative approaches have shown comparable functional results in certain cohorts, with the added benefit of avoiding surgical risks and complications. This highlights the need for individualized treatment decisions based on patient-specific factors, such as age, activity level, cosmetic concerns, and tolerance for potential complications. Ultimately, while our analysis focused on comparing surgical techniques, the broader context of operative versus nonoperative management should be acknowledged as equally critical to clinical decision-making. Further high-quality, long-term studies comparing surgical and nonsurgical treatments are warranted to elucidate the nuanced differences and guide optimal management strategies for ACJ injuries.

As our understanding of the anatomical mechanisms governing the ACJ deepens, and the concept of biological fixation or reconstruction gains traction, reconstruction of the coracoclavicular ligament has emerged as an innovative approach for clinical exploration among medical practitioners. The advancements in internal fixation techniques and the widespread adoption of arthroscopic procedures have provided a conducive environment for this endeavor. Arthroscopic coracoclavicular ligament reconstruction using a suture button, in combination with high-strength suture, has garnered increasing favor among orthopedic surgeons. This approach not only embodies the benefits of minimally invasive surgery but also aligns with the anatomical and biomechanical intricacies of the ACJ. Chen et al. have identified a significant risk factor for reduction loss with the open Endobutton technique as the misplacement of the clavicular hook plate due to deviation of the subcoracoid bone tunnel from the center (21). However, this challenge can be effectively addressed through the combined application of arthroscopic and hook plate techniques, with direct visualization facilitating accurate placement. Moreover, arthroscopic techniques offer the added advantage of diagnosing and treating concomitant intra-articular injuries, while enabling direct visualization of the inferior aspect of the coracoid base during arthroscopic surgery, thus obviating the need for separate internal fixation device removal procedures (22). Nonetheless, this approach is not without its limitations, such as the potential for synthetic material-induced synovitis due to clavicular rotation causing a sawing effect. In addition, its relatively invasive nature, with considerable invasion of the coracoid base, may lead to anterior subluxation of the clavicle, potentially resulting in suboptimal postoperative ACJ reduction (8, 23). However, no relevant complications were reported in the studies included in our analysis.

Mini-incision approaches are considered valuable alternatives to arthroscopic-assisted techniques. They can be easily implemented for single- or double-tunnel coracoclavicular reconstruction, with or without acromioclavicular loop fixation, and have been shown to yield similar clinical outcomes (24, 25). Given the potential for concomitant intra-articular pathology in shoulder injuries, arthroscopic suture button fixation not only reconstructs the function of the coracoclavicular ligament but also allows for the clearance of intra-articular pathology, a task unachievable with open approaches. Therefore, future studies should not only focus on comparing functional scores between the two groups but also compare the management of intra-articular pathology. In addition to functional outcomes and pain relief, cosmetic outcomes are an important aspect of patient satisfaction that warrants further attention. Arthroscopic-assisted techniques generally result in smaller scars compared to mini-incision or open techniques. The reduced scarring associated with arthroscopy is particularly significant for younger or more cosmetically conscious patients, as visible scars in the clavicular region may cause esthetic concerns or affect patient confidence. Conversely, mini-incision approaches, while less invasive than traditional open surgery, still leave a more noticeable scar, which could influence patient preferences. Although there were no differences in postoperative functional scores and pain ratings between the two approaches, the superior cosmetic results offered by arthroscopic-assisted surgery may provide an additional advantage in eligible patients. Future studies should include patient-reported outcomes related to scar satisfaction and appearance to better understand the full impact of cosmetic differences on quality of life and decision-making.

Strengths and limitations

To our knowledge, this is the first meta-analysis to present the existing evidence regarding the effects of arthroscopic and open surgery for the treatment of acute high-grade ACJ dislocation using suture button. This study includes all available primary evidence. As such, it represents a comprehensive overview of the topic and critically analyzes previously conducted trials. In addition, this study will generate significant interest from the public.

However, our study has the following limitations: First, apart from the two RCTs included in our meta-analysis, the remaining three studies are retrospective cohorts. This results in lower levels of evidence and diminishes the strength of the conclusions drawn. Second, Rockwood grading was not fully considered. However, this was inevitable as they were not subcategorized in the original studies. Third, the included studies involved different types of SB and fixation methods, such as single bundle and double bundle, which may lead to differences in results. Fourth, the surgical time, as a metric included in our analysis, may not solely reflect the superiority of one surgical technique over another. Instead, it is influenced by the skill level and experience of individual surgeons. A longer learning curve for some surgical techniques might also contribute to variations in surgical time. Future studies should account for the surgeon’s experience when comparing surgical techniques. Fifth, although we have incorporated ACD measurements into our analysis to complement CCD, the radiographic comparisons in the included studies were still limited to two-dimensional assessments. This approach may not fully capture the three-dimensional anatomical changes or instability associated with ACJ injuries. Future studies should consider utilizing multi-plane imaging techniques to provide a more comprehensive evaluation.

Conclusions

Based on the available evidence, there were no significant differences observed in postoperative CS, VAS, CCD, ACD, or complications between arthroscopic fixation and open fixation using suture button. However, arthroscopic procedures required longer operation time compared to open approaches. Despite this, the unique advantages of arthroscopy, including its ability to address intra-articular pathologies and achieve superior cosmetic outcomes, may provide added value for select patients. With continuous advancements in arthroscopic techniques and improvements in surgeon training, arthroscopic fixation holds promise as an increasingly viable and potentially preferable option in the future.

ICMJE Statement of Interest

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the work reported.

Funding Statement

This work was supported by the Enze Medical Center (Group) Scientific Research (No. 23EZA04) and Zhejiang Medicine and Health Scientific Research Project (No. 2024KY1794). The funder had a specific role in the preparation of the manuscript.

Author contribution statement

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data. HL prepared the first manuscript draft. CC, JY, and CY provided critical input and technical expertise, enhancing the quality and rigor of the revised work. All authors contributed to final edits and revisions before submission.