Bosworth and modified Phemister techniques revisited. A comparison of intraarticular vs extraarticular fixation methods in the treatment of acute Rockwood type III acromioclavicular dislocations

Surgical Advances in the Treatment of Acromioclavicular Joint Injury: A Comprehensive Review

In this article, we aim to review the diagnosis, classification, and treatment of acromioclavicular joint injury by mainly describing the progress of surgical treatment for acromioclavicular joint injury, providing a reference for clinical diagnosis and treatment. Acromioclavicular joint injury is a common sports injury, which is more common in male than in female patients. The mechanism of the injury is mainly caused by direct or indirect violence, which can be clearly diagnosed by radiography. According to the time after injury, it can be divided into acute injury and chronic injury. The Rockwood classification is the most commonly used classification in research. For Rockwood types V to VI, we treat with surgery, while the treatment options for type III are controversial and no consensus has been reached. Surgical treatment can be divided into open surgery and shoulder arthroscopy. The methods of open surgery can be divided into 3 categories: direct acromioclavicular joint fixation, coracoclavicular space suspension device fixation, and coracoclavicular ligament reconstruction. The shoulder arthroscopy method involves reconstruction of the coracoclavicular ligament under arthroscopy, combined with suture-button suspension fixation. For patients with Rockwood classification III and IV-VI, who have significant movement needs, surgery is the preferred treatment for acute acromioclavicular dislocation within 3 weeks. For patients with a chronic acromioclavicular dislocation or who do not respond to nonsurgical treatment, it is recommended to use wire suspension fixation combined with ligament to repair the damage. This article aims to review advances in the management of acromioclavicular joint injury.

Functional Outcomes of the Management of Acromioclavicular Joint Dislocation With a Clavicle Hook Plate: A Retrospective Study

BACKGROUND

Dislocation of the acromioclavicular joint (ACJ), accounting for 9%-12% of all shoulder injuries, is a frequent shoulder problem. Clavicular hook plates have proven to be a successful implant choice for surgical management. The benefit of this method is that it preserves the diarthrosis of the ACJ while reducing dislocation. Positive outcomes with this approach have been reported.

OBJECTIVE

This study aimed to quantify functional recovery using the Constant Murley Score (CMS) in patients with ACJ dislocations treated with a clavicle hook plate.

METHODOLOGY

The retrospective study was conducted at the orthopedic department of Sheikh Zayed Medical College and Hospital, Rahim Yar Khan, Pakistan, for over one year, from January 20, 2021, to 19 January, 2022. A total of 40 individuals were identified who were operated on for acute ACJ dislocation with hook plates in the department and were included in the research. All patients underwent open reduction and internal fixation with a clavicular hook plate, which was usually removed three months after surgery. The functional outcome was evaluated using the CMS on the day before plate removal, three months after plate removal, and six months following surgery.

RESULTS

Of the participants, 28 (70%) were male, and 12 (30%) were female. The mean CMS was 72.25 ± 3.95 (satisfactory) at 24 weeks and 90.45 ± 1.9 (excellent) eight weeks after the removal of the plate.

CONCLUSION

The hook plate is an excellent choice for treating acute ACJ dislocation. Radiographic and functional assessments indicate that these plates provide good outcomes.

Choice of Acromioclavicular Dislocation Treatment Should Not Be Influenced by Risk of Development of Acromioclavicular Osteoarthritis: A Systematic Review With Meta-Analysis

BACKGROUND

It is currently unknown to what degree surgical or nonoperative treatment of acromioclavicular (AC) dislocation influences the development of osteoarthritis (OA). The aim of this study was to evaluate AC OA after surgical and nonoperative treatment for AC dislocations, compare OA prevalence between treatment options, and compare OA prevalence between the injured and contralateral shoulder.

METHODS

Articles reporting on the prevalence of OA after surgical or nonoperative treatment of an AC dislocation with a minimal 2-year follow-up were included. AC OA presence was extracted for the injured and contralateral shoulder. Treatment categories were defined based on anatomical variation in the reattachment of ligaments: AC fixation, coracoclavicular (CC) fixation, AC and CC fixation, Bosworth screw synthetic graft, tendon graft, and conservative. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.

RESULTS

Ninety-four articles were included for qualitative analysis, and 7 articles were included for meta-analysis (n = 3,812; follow-up = 2.0-24.2 years; mean age 37.6 ± 10.4 years). A total of 3,483 patients underwent surgical treatment, and 329 patients underwent conservative treatment. OA prevalence ranged from 6.7%-29.3% between 7 pooled treatment categories. Most included studies had a follow-up <10 years (94%) and OA prevalence increased with time, regardless of treatment option. There was no difference in OA prevalence between the injured and contralateral shoulder (p = 0.120). MINORS scores were varied, ranging from poor to very good.

CONCLUSION

The pooled AC OA prevalence of the 7 treatment categories ranged from 6.7% for the CC fixation surgical group to 29.3% for the conservative treatment group. However, the included studies were predominantly of low quality and had varying follow-up periods, with most having relatively short follow-up durations. No difference in AC OA prevalence was found between the injured and contralateral shoulder. Based on the available evidence, treatment choice for AC dislocation should not be influenced by the potential development of AC AO.

LEVEL OF EVIDENCE

Level IV. See Instructions for Authors for a complete description of levels of evidence.

Comparison of Effectiveness and Safety in Treating Acute Acromioclavicular Joint Dislocation with Five Different Surgical Procedures: A Systematic Review and Network Meta-Analysis

This network meta-analysis aims to evaluate the comparative effectiveness and safety of suture anchors (SA), tendon grafts (TG), hook plates (HP), Tight-Rope (TR), and EndoButton (EB) in the treatment of acute acromioclavicular joint (ACJ) dislocation. The Embase, PubMed, and Web of Science databases were searched from their inception date to June 3, 2022. Studies included all eligible randomized controlled trials (RCTs) and cohort studies with the comparison of five different fixation systems among SA, TG, HP, TR, and EB were identified. All studies were reviewed, performed data extraction, and assessed the risk of bias independently by two reviewers. The primary outcomes are Constant-Murley score (CMS) improvement for assessing clinical efficacy, and complications. The second outcomes are visual analog scale (VAS) for assessing pain relief and the coracoclavicular distance (CCD) for assessing postoperative joint reduction. Version 2 of the revised Cochrane risk of bias tool for randomized trials (RoB 2) and the risk of bias in nonrandomized studies of interventions (ROBINS-I) were used to assess the RCTs and non-randomized trials, respectively. The continuous outcomes were presented as mean differences (MD), and risk ratios (OR) were used for dichotomous outcomes, both with 95% confidence intervals (CI). Surface under the cumulative ranking curves (SUCRA) results were calculated to offer a ranking of each intervention. We identified 31 eligible trials, including 1687 patients in total. HP showed less CMS improvement than TR and EB in both the Network Meta-analysis (NMA) and pairwise meta-analysis. HP also showed less CMS improvement than SA in NMA. For pain relief, HP performed worse than TR both in pairwise meta-analysis and NMA. No significant differences were found for the measured value of CCD. Both TR and EB showed a lower incidence of complications than HP in pairwise meta-analysis. The rank of SUCRA for CMS improvement was as follows: SA, TR, EB, TG, and HP; for pain relief: TR, EB, TG, SA, and HP; for CCD: HP, TR, SA, EB, and TG. For complications, HP showed the highest rank, followed by TG, EB, TR, and SA. SA shows better clinical effectiveness and reliable safety in the treatment of acute ACJ dislocation. Although HP is the most widely used surgical option currently, it should be carefully taken into consideration for its high incidence of complications.

Treatment options for acute Rockwood type III-V acromioclavicular dislocations: a network meta-analysis of randomized controlled trials

BACKGROUND

Acute Rockwood type III-V acromioclavicular (AC) dislocations have been treated with numerous surgical techniques over the years. The purpose of this study was to perform a network meta-analysis (NMA) of randomized controlled trials to quantitatively define the optimal treatment for AC dislocations requiring operative treatment.

METHODS

A literature search of 3 databases was performed based on Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Randomized controlled trials comparing 1 of 10 treatments for acute Rockwood type III-V AC dislocations-nonoperative treatment, Kirschner wire fixation (KW), coracoclavicular screw fixation (Scr), hook plate (HP), open coracoclavicular cortical button (CBO), arthroscopic coracoclavicular cortical button (CBA), ≥2 coracoclavicular cortical buttons (CB2), isolated graft reconstruction (GR), cortical button with graft augmentation (CB-GR), and coracoclavicular and acromioclavicular fixation (AC)-were included. Clinical outcomes were compared using a frequentist approach to NMA, with statistical analysis performed using the R program. Treatment options were ranked using the P-score, which estimates the likelihood that the investigated treatment is the ideal method for an optimal result in each outcome measure on a scale from 0 to 1.

RESULTS

Of 5362 reviewed studies, 26 met the inclusion criteria, with a total of 1581 patients included in the NMA. AC, CB-GR, GR, CB2, CBA, and CBO demonstrated superiority over HP, Scr, KW, and nonoperative treatment at final follow-up for the Constant-Murley score and Disabilities of the Arm, Shoulder and Hand score, with AC and CB-GR showing the highest P-scores for the Constant-Murley score (0.957 and 0.781, respectively) and GR and CBO showing the highest P-scores for the Disabilities of the Arm, Shoulder and Hand score (0.896 and 0.750, respectively). GR had the highest P-score for the visual analog scale score (0.986). HP, CB2, CB-GR, AC, CBA, and CBO demonstrated superiority in the coracoclavicular distance (CCD) and recurrence at final follow-up, with HP and CB2 having the highest P-scores for the CCD (0.798 and 0.757, respectively) and with GR and CB-GR having the highest P-scores for recurrence (0.880 and 0.855, respectively). KW and Scr showed the shortest operative times (P-scores of 0.917 and 0.810, respectively), whereas GR and CBA showed the longest operative times (P-scores of 0.120 and 0.097, respectively).

CONCLUSIONS

Although there are multiple fixation options for acute Rockwood type III-V AC dislocations, adding AC fixation or graft augmentation likely improves functional outcomes and decreases the CCD and recurrence rate at final follow-up-at the expense of longer operative times.

Can a coracoclavicular screw added to the clavicular hook plate reduce subacromial stress? A finite element analysis

OBJECTIVES

The aim of this study was to investigate the stresses on the plate and the clavicle in the standard clavicular hook plate model and the clavicular hook plate models with a coracoclavicular (CC) screw by finite element analysis (FEA).

MATERIALS AND METHODS

The FEA models were created with the combination of acromion, clavicle, coracoid process, 8-hole clavicular hook plate and screw components. Model 1 was created as a standard clavicular hook plate model and plates were implanted to the clavicle and the acromion by six locking screws. Model 2 was created by a cortical screw placed in the coracoid process through the third hole of the plate (CC screw) and fixation of hook plate by five locking screws. The upward-pull force was applied to clavicle at the insertion of sternocleidomastoid muscle with three axes. The stress exerted by acromion on the hook of the plate, stresses on the plate, clavicle, and CC screw were analyzed.

RESULTS

When the screw holes were compared, in Model 1, the highest stress was found in the last hole of the plate. In Model 2, the highest stress was detected on the CC screw. The stress on the clavicle was found to be 0.14 Mpa in Model 1 and 0.21 Mpa in Model 2. In Model 1 and Model 2, the stress exerted by acromion on the subacromial part of the plate was found to be 2.05 KPa and 1.66x10-6 KPa, respectively.

CONCLUSION

The results of this study show that addition of CC screw to the standard clavicular hook plate shares the loading and reduces the stress on the hook of the plate.

Surgical Management of Acute Rockwood Grade III Acromioclavicular Joint Dislocations: A Systematic Review

Injuries of the acromioclavicular joint (ACJ) occur frequently in young and active people. The best management of acute grade III injuries has been a source of controversy and extensive debate. When surgery is indicated, there is still no gold standard surgical technique for treating acute grade III ACJ injuries. The methodology of this review was a comprehensive search of PubMed, Medline, Cochrane, and EMBASE databases using various combinations of the keywords "Rockwood," "type III," "grade III," "treatment," "surgery," "acromioclavicular joint," and "dislocation," since the inception of the databases to December 2020. Surgical techniques were divided into two groups. In group 1 were ACJ fixation techniques using hardware such as the hook plate, Kirschner wires, and wire cerclage; group 2 included coracoclavicular (CC) ligament fixation/reconstruction techniques using double buttons, TightRope®, suture anchors, Endobuttons, the Infinity-LockTM Button System, etc. Fourteen studies were selected for the final review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review showed better outcome scores in group 2. Overall, complication rates were higher in group 1 compared to group 2. The results of this review show that CC fixation, using suspensory or loop devices, of Rockwood grade III injuries, has better outcomes and fewer complications than fixation of the ACJ with hardware.

Does coracoclavicular augmentation additional to hook plate fixation provide benefits in acute unstable acromioclavicular dislocation? A meta-analysis

Background

Acromioclavicular joint (ACJ) dislocation is a common shoulder injury. In treating acute unstable ACJ dislocation, a hook plate (HP) is a straightforward and popular option for ensuring proper reduction and rigid fixation while promoting AC and coracoclavicular (CC) ligament healing. Surgeons typically remove the HP to prevent subacromial impingement and acromial osteolysis; however, concerns about redislocation after implant removal remain. Therefore, additional CC augmentation may be helpful in combination with HP fixation. The aim of this meta-analysis is to compare the outcomes and complications of HP fixation with or without additional CC augmentation for acute unstable ACJ dislocation.

Methods

We searched the PubMed, EMBASE, and Web of Science databases for relevant case–control studies. The primary outcomes were patient-reported outcome measures; the secondary outcomes were pain measured using a visual analog scale (VAS), CC distance (CCD), and complications. Continuous data were assessed using weighted standardized mean differences (SMDs) with 95% confidence intervals (CIs), and dichotomous data were evaluated with Mantel–Haenszel odds ratio (ORs) with 95% CIs.

Results

We analyzed one randomized control trial and four case–control studies comparing HP fixation with or without CC augmentation. A total of 474 patients with Rockwood type III or V ACJ dislocation were included. We found no differences in Constant–Murley score (SMD, − 0.58, 95% CI − 1.41 to 0.26; P = 0.18), American Shoulder and Elbow Surgeons score (SMD, 0.21, 95% CI − 0.10 to 0.52; P = 0.19), University of California at Los Angeles shoulder rating scale score (SMD, − 0.02, 95% CI − 1.27 to 1.23; P = 0.97), or VAS pain score (SMD, 0.36, 95% CI − 0.16 to 0.88; P = 0.17) between groups. The CC augmentation group had lower odds of osteolysis (OR, 0.27, 95% CI 0.10 to 0.74; P = 0.01) and a shorter CCD (SMD, − 0.29, 95% CI − 0.57 to − 0.01; P = 0.04).

Conclusion

HP fixation with CC augmentation is preferable for acute unstable ACJ dislocations. Although CC augmentation did not provide additional benefits related to functional outcomes or pain, it resulted in greater reduction maintenance after implant removal and a 73% lower risk of acromial osteolysis.

Trial registration

PROSPERO (CRD42021271118).

Biologic and synthetic ligament reconstructions achieve better functional scores compared to osteosynthesis in the treatment of acute acromioclavicular joint dislocation

PURPOSE

To systematically review the outcomes of surgical treatments of acute acromioclavicular joint dislocation.

METHODS

Studies were identified by electronic databases (Ovid, PubMed). All studies reporting functional and radiological outcomes of surgical treatments of acute acromioclavicular joint dislocations were included. Following data were extracted: authors and year, study design, level of evidence, number of patients, age, classification of acromioclavicular joint dislocation, time to surgery, surgical technique, follow-up, clinical and imaging outcomes, complications, and failures. Descriptive statistics was used, when a data pooling was not possible. Comparable outcomes were pooled to generate summary outcomes reported as frequency-weighted values. Quality appraisal was assessed through the MINORS checklist.

RESULTS

One hundred and thirty-three studies were included for a total of 4473 shoulders. Mean age of participants was 36.9 years. Mean follow-up was 42.06 months. Arthroscopy showed better ASES (p < 0.0001) and lower VAS pain score (p = 0.0249) compared to an open approach. Biologic and synthetic reconstructions demonstrated better results over osteosynthesis techniques. Biologic techniques showed overall better Constant (p = 0.0001) and DASH (p = 0.0215) scores, while synthetic reconstruction showed better UCLA score (p = 0.0001). Among suture buttons, triple button showed overall better results in Constant (p = 0.0001) and VAS (p = 0.0001) scores, while better results in DASH score (p = 0.0003) were achieved by 2 double button techniques. Overall, the level of evidence was low.

CONCLUSION

Biological and synthetic reconstructions achieved better functional scores compared to osteosynthesis. Among suture buttons, the triple button showed better functional performance.

LEVEL OF EVIDENCE

IV.

Comparison of Hook Plate Fixation Versus Arthroscopic Coracoclavicular Fixation Using Multiple Soft Anchor Knots for the Treatment of Acute High-Grade Acromioclavicular Joint Dislocations

PURPOSE

To compare the clinical and radiologic outcomes of arthroscopically assisted coracoclavicular (CC) fixation using multiple soft anchor knots versus hook plate fixation in patients with acute high-grade Rockwood type III and V acromioclavicular (AC) joint dislocations.

METHODS

This retrospective study included 22 patients with acute Rockwood type III and V AC joint dislocations who underwent arthroscopic fixation or hook plate fixation surgery between February 2016 and March 2018. Patients were categorized into 2 groups: arthroscopically assisted CC fixation using multiple soft anchor knots group (AR, n = 12) and hook plate fixation group (HO, n = 10). We measured the CC distances (CCDs) and CCD ratio at 6 months, 1 year, and last follow-up postoperatively to compare the radiologic results between the groups. Clinical outcomes were assessed at 1 year postoperatively and at the last follow-up using the Visual Analog Scale, American Shoulder and Elbow Surgeons (ASES) scores, and Shoulder Pain and Disability Index (SPADI) scores, and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Magnetic resonance imaging after hook plate removal was used to evaluate the healing ligaments and tendon-bone interface.

RESULTS

The patients in the AR group had better ASES, SPADI, and Quick DASH scores than the patients in the HO group at 1 year postoperatively and at last follow-up. The CCD and CCD ratio were significantly better in the AR group than in the HO group at the last follow-up period (P = .007/0.029). Magnetic resonance imaging findings showed grade I in 60% of patients in the AR group and grade III in 60% of patients in the HO group. AC joint arthritic change was observed in 40% of the HO group.

CONCLUSIONS

The CC fixation method using multiple soft anchor knots showed satisfactory results and had superior CC ligament healing ability and maintenance of CCD than hook fixation.

LEVEL OF EVIDENCE

Level III, retrospective therapeutic comparative investigation.

Treatment of acute high-grade acromioclavicular joint dislocation

Acromioclavicular (AC) joint dislocations account for about 9% of shoulder injuries. Among them, acute high-grade injury following high-energy trauma accounts for a large proportion of patients requiring surgical treatment. However, there is no gold standard procedure for operative treatment of acute high-grade AC joint injury, and several different procedures have been used for this purpose in clinical practice. This review article summarizes the most recent and relevant surgical options for acute high-grade AC joint dislocation patients and the outcomes of each treatment type.

The frequency of reduction loss after arthroscopic fixation of acute acromioclavicular dislocations using a double-button device, and its effect on clinical and radiological results

Background

The aim of this study was to investigate the effect of reduction loss of more than 3 mm on clinical and radiological results after at least 2 years of follow-up after arthroscopic fixation of acute acromioclavicular joint dislocations using a double-button device.

Methods

Thirty-six patients who had acute (< 3 weeks old), type III or V acromioclavicular (AC) joint dislocations underwent arthroscopic fixation of the AC joint using a double-button device. Clinical and radiological evaluations were performed at preoperative, postoperative first day, 3 months and last follow-up. When the coracoclavicular (CC) distances of patients at the last follow-up were compared to the early postop CC distances, those with a difference of 3 mm or less were grouped as group A and those with a difference of more than 3 mm were grouped as group B.

Results

There was no statistically significant difference between the groups in terms of age, gender, follow-up time, time from injury to surgery, return to work, and distribution of Rockwood classification. Pre-operative CC distance was reduced from 18.7 ± 3.5 to 8.5 ± 0.6 in the early postoperative period. Anatomic reduction was achieved in all patients compared with the unaffected side (CC distance 8.6 ± 0.7). However, the CC distance increased to 9.9 ± 1.5 at the third-month follow-up and increased to 11 ± 2.7 at the last follow-up. There were no significant Constant score differences between the groups in the preoperative and last follow-up periods (p > 0.05). At the last follow-up, the mean Acromioclavicular Joint Instability (ACJI) score of group A was 84.4 ± 8, whereas it was 68.3 ± 8.3 for group B, and the difference was statistically significant (p < 0.01). Furthermore, the subjective evaluation and aesthetic subjective satisfaction values of group B were lower than group A (p < 0.01).

Conclusions

Reduction loss of more than 3 mm was observed in 25% of patients after arthroscopic fixation of acute acromioclavicular dislocations using a double-button device. Although this loss did not create a statistically significant difference in Constant scores, AC joint-specific tests such as ACJI, subjective evaluation, and aesthetic subjective satisfaction values were significantly impaired.

Optimal Management of Acromioclavicular Dislocation: Current Perspectives

Injuries to the acromioclavicular (AC) joint are common and mostly involve younger, male individuals. Whereas the majority of AC joint dislocations can be treated nonoperatively with a trial of immobilization, pain medication, cryotherapy, and physiotherapy, there are patients that do not respond well to conservative management and may require surgical treatment. Identifying and treating these patients according to the type and chronicity of AC joint dislocation is paramount. To date, a myriad of surgical techniques have been proposed to address unstable AC joint dislocations and are indicative of the uncertainty that exists in optimal management of these injuries. Historically research has focused on the restoration of the coracoclavicular ligament complex. However, recently the importance of the acromioclavicular capsule and ligaments has been emphasized. This review aims to provide the reader with an overview of current treatment strategies and research, as well as future perspectives.

Comparison of clavicular hook plate with and without coracoclavicular suture fixation for acute acromioclavicular joint dislocation

Objective

The aim of this study was to compare the clinical and radiographic outcomes of clavicular hook plate fixation with and without coracoclavicular (CC) tape augmentation for the treatment of acute unstable AC dislocation.

Methods

We treated 47 patients (31 men and 16 women; mean age: 47 years (range, 21–81)) with unstable acute AC dislocations (Rockwood III–V) and divided them into two groups according to the treatment modality, with hook plate fixation (hook plate group) or hook plate plus CC tape augmentation (combined group). We assessed radiologic findings, such as subacromial osteolysis and AC osteoarthritis. We also evaluated the clinical outcomes using a visual analogue scale (VAS) for pain, as well as the University of California at Los Angeles (UCLA) Shoulder Rating Scale and the American Shoulder and Elbow Surgeons (ASES) Shoulder Score.

Results

We found that the combined group had less subacromial osteolysis upon radiography, although the CC distance was similar in both groups (119 ± 29.7% of contralateral side CC distance in hook plate group versus 119 ± 34.8% in the combined group, p = 0.77). Compared with the hook plate group, the combined group had a lower VAS score (4.5 ± 2.3 in hook plate group versus 2.3 ± 1.4 in the combined group, p < 0.001), better UCLA scores (19.9 ± 4.9 in hook plate group versus 27.2 ± 4.0 in the combined group, p < 0.001) as well as better ASES scores (51.9 ± 17.8 in hook plate group versus 73.8 ± 13.1 in the combined group, p < 0.001) at 3 and 6 months after surgery.

Conclusion

Hook plate fixation plus CC tape augmentation may prevent subacromial osteolysis and yield better short-term functional outcomes.

Level of Evidence

Level III, Therapeutic Study.

Arthroscopic Coracoclavicular Fixation Technique Using Multiple All-Suture Anchors

Acromioclavicular (AC) joint dislocation is a common injury, particularly among active young individuals. Numerous surgical procedures for treating acute, high-grade AC joint dislocation have been reported. However, no standard surgical procedure that restores the normal kinematics of the AC joint is available. Among the available coracoclavicular (CC) fixation techniques, cortical button fixation was recently introduced, and it has had successful outcomes. Moreover, it is advantageous because it can be used in arthroscopic procedures. However, because of the limited number of fixation tools, a fundamental problem in terms of horizontal instability and gradual subsidence of cortical buttons has been observed, eventually leading to a threat to vertical stability. Therefore, we developed a unique CC fixation technique with multiple small tunnels using all-suture anchors, which may overcome potential complications caused by cortical buttons that require bone tunnels with relatively large diameters. This arthroscopic CC fixation technique was designed to achieve the ideal horizontal and vertical stability that may restore native AC kinematics.