Structural properties of the intact and the reconstructed coracoclavicular ligament complex

Functional reconstruction of chronic acromioclavicular joint separation using a double suture technique combined with semitendinosus autograft

PURPOSE

We present the functional and clinical results of a combined surgical technique that functionally restores chronic Acromioclavicular Joint Instability (AJI). The method combines a double-looped suture fixation augmented with a semitendinosus autograft.

METHODS

Between 2017 and 2021, 15 patients were treated using the surgical technique. All patients suffered an Acromioclavicular Joint Separation that remained untreated for at least 6 (6-16) weeks after the initial injury. Four Ethibond sutures were passed below the coracoid process and through a 4.5 drill hole in the clavicle. The sutures provided adequate horizontal and vertical reduction and stabilization of the clavicle. A semitendinosus autograft was passed below the coracoid process and looped around the clavicle. The remaining graft limbs were used to reconstruct the acromioclavicular capsule. Patients were radiologically evaluated with bilateral anteroposterior (AP), Zanca, and Alexander views. The clinical evaluation was based on the Acromioclavicular Joint Instability Score and the Constant-Murley Score.

RESULTS

The mean follow-up period was 31.2 months (17-61). The mean last ACJIS and CMS scores were 96 (90-100) and 97.67 (87-100), respectively. Reduction of the clavicle was radiologically confirmed in all cases throughout the follow-up period. AC arthritis was reported in 1 case without associated clinical symptoms. No significant complications were reported, and all patients returned to the pre-injury activity level.

CONCLUSION

The presented functional reconstruction of the AC joint disruption in chronic cases is an effective and secure method with low complication rates and good clinical results.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Acromioclavicular joint Stabilization: Our experience with the lockdown technique

Background

Acromioclavicular joint (AC joint) disruption is a common injury with considerable variation with regards to surgical management. The Lockdown™ procedure (previously known as Surgilig™), Modified Weaver-Dunn procedure, Arthroscopic AC joint stabilization and Ligament Augmentation and Reconstruction system (LARS) procedure have all been described for treatment of this injury with varying outcomes.

Purpose

To measure the functional and radiological outcomes following all cases of AC joint reconstruction using the Lockdown™ technique over the last 10 years at Medway Maritime Hospital.

Methods

Data on a total of 53 patients who underwent AC joint reconstruction between 2012 and 2021 were collected. Electronic records were used to extract data regarding patient characteristics, surgery details, and duration of follow-up. Telephonic interviews of patients were conducted to collect data on hand dominance, surgical complications, and responses to Oxford shoulder score (OSS) and QuickDASH score questionnaires. Hospital PACS data were reviewed to record preoperative injury severity and postoperative acromioclavicular joint reduction.

Results

Results for 42 patients were available and analysed as 10 could not be contacted and 1 patient sadly passed away. Of the patients reviewed, 92.9% were males with a mean age of 42.2 years (Range 16-67 years) and mean follow up of 68 months (12-119.1 months). The injury involved the dominant arm in 59.5%cases. Majority of the cases were Rockwood type V injuries (71.43%) while the rest were either type III(19.05%) or type IV(9.52%).The mean preoperative OSS was 21.3/48 which improved to 44.3/48 in the postoperative period. Similarly, the mean QuickDASH score was 50.6 preoperatively, that improved to 9.1 postoperatively.The most common patient reported complication was prominent metalwork seen in 5 cases (11.6%) followed by stiffness seen in 3 cases (7%) and superficial infection seen in 1 case (2.3%). The AC joint remained reduced radiologically in 81% of cases, while a resubluxation between 50 and 100% was seen in the rest of the cases. Patients with radiological resubluxation did not report this as a complication in 87.5% of the cases. Overall, 38 patients reported their outcome as excellent, 2 patients rated it good while 1 patient reported it as fair and 1 as poor.

Conclusion

The Lockdown™ technique for stabilization of AC joint has excellent or good patient satisfaction in 95.2% of cases in long term follow up of more than 5.7 years. Prominent metalwork and stiffness are the commonest clinical complications. Radiological resubluxation can be seen in a fifth of the cases but does not directly lead to patient dissatisfaction.

Level of evidence

Level IV Retrospective case series.

Acromioclavicular Joint Anatomy and Biomechanics: The Significance of Posterior Rotational and Translational Stability

The shoulder girdle extends from the sternoclavicular joint to the scapular stabilizing muscles posteriorly. It consists of 3 joints and 2 mobile regions. The shoulder girdle is statically stabilized by the acromioclavicular and coracoclavicular capsuloligamentous structures and dynamically stabilized by the trapezius, deltoid, and deltotrapezial fascia. During humerothoracic elevation, the clavicle elevates, protracts, and rotates posteriorly through the sternoclavicular joint while the scapula tilts posteriorly and rotates upward. The purpose of this article is to review the anatomy and biomechanics of the acromioclavicular joint and the shoulder girdle.

Anatomic Acromioclavicular Joint Reconstruction with and without Acromioclavicular Ligament Reconstruction: A Comparative Biomechanical Study

Background

The purpose of this study was to determine if adding a reconstructed superior acromioclavicular (AC) joint ligament adds significant biomechanical stability to the AC joint over anatomic coracoclavicular (CC) ligament reconstruction alone.

Methods

Fourteen cadaver shoulders were used for the comparison of biomechanical stability among the anatomic CC ligament reconstruction alone, CC and AC ligament reconstruction, and the intact groups by measuring the displacement under cyclic loads. A load to failure test was then performed in the vertical direction at a loading rate of 2 mm /sec to determine surgical-repair joints' tolerance to the maximum failure load.

Results

The average peak-to-peak displacement induced by cyclic load in the sagittal axis and vertical axis direction was not significantly different between CC ligament reconstruction, CC and AC ligament reconstruction, and intact groups. The maximum failure load for the CC reconstruction (224.9 ± 91.8 N (Mean ± SEM)) was lower than CC/AC reconstruction groups (326.2 ± 123.3 N). The CC/AC reconstruction group failed at a significantly higher load (t test, p = 0.016) than the CC reconstruction group.

Conclusion

CC/AC reconstruction surgical technique yielded a better shoulder stability than CC ligament alone reconstruction that may better maintain reduction of the AC joint.Level of Evidence: Level II.

Acromioclavicular Joint Injuries in Sport

ABSTRACT

Sport-related shoulder injuries, including disruptions to the acromioclavicular joint (ACJ), are common. An ACJ injury is classified by the degree and direction of the clavicle displacement. Although the diagnosis can be made clinically, standard radiographic views are important to determine the severity of the ACJ disruption and assess for concurrent injuries. The majority of ACJ injuries can be managed nonoperatively; however, surgical treatment is indicated in some cases. Long-term outcomes are generally favorable for most ACJ injuries, and athletes generally return to sport without functional limitations. This article provides an in-depth discussion regarding all aspects of ACJ injuries, including clinically relevant anatomy, biomechanics, evaluation, treatment, and complications.

Current concepts in acromioclavicular joint (AC) instability - a proposed treatment algorithm for acute and chronic AC-joint surgery

BACKGROUND

There exists a vast number of surgical treatment options for acromioclavicular (AC) joint injuries, and the current literature has yet to determine an equivocally superior treatment. AC joint repair has a long history and dates back to the beginning of the twentieth century.

MAIN BODY

Since then, over 150 different techniques have been described, covering open and closed techniques. Low grade injuries such as Type I-II according to the modified Rockwood classification should be treated conservatively, while high-grade injuries (types IV-VI) may be indicated for operative treatment. However, controversy exists if operative treatment is superior to nonoperative treatment, especially in grade III injuries, as functional impairment due to scapular dyskinesia or chronic pain remains concerning following non-operative treatment. Patients with a stable AC joint without overriding of the clavicle and without significant scapular dysfunction (Type IIIA) may benefit from non-interventional approaches, in contrast to patients with overriding of the clavicle and therapy-resistant scapular dysfunction (Type IIIB). If these patients are considered non-responders to a conservative approach, an anatomic AC joint reconstruction using a hybrid technique should be considered. In chronic AC joint injuries, surgery is indicated after failed nonoperative treatment of 3 to 6 months. Anatomic AC joint reconstruction techniques along with biologic augmentation (e.g. Hybrid techniques, suture fixation) should be considered for chronic high-grade instabilities, accounting for the lack of intrinsic healing and scar-forming potential of the ligamentous tissue in the chronic setting. However, complication and clinical failure rates remain high, which may be a result of technical failures or persistent horizontal and rotational instability.

CONCLUSION

Future research should focus on addressing horizontal and rotational instability, to restore native physiological and biomechanical properties of the AC joint.

Triple Endobutton technique for the treatment of Neer type II lateral clavicle fractures: 2-year findings

BACKGROUND

Although various kinds of operative procedures have been reported in the literature, there is still no undisputed gold standard technique for the treatment of Neer type II lateral clavicle fractures. This trauma is classified as a bone fracture, but it is primarily a ligamentous problem due to the instability it generates. This study analyzed the clinical and radiological results of treatment for Neer type II lateral clavicle fractures using the triple Endobutton (Smith & Nephew) technique in 20 patients with at least 2 years of follow-up.

METHODS

This study enrolled 20 patients with Neer type II distal clavicle fractures who underwent the triple Endobutton technique using 3 Endobuttons (1 with a closed loop and 2 without) and 3 No. 5 Ethibond sutures (Ethicon Inc.) from October 2017 to May 2020. Patients were assessed with clinical and radiological follow-up at 3, 6, 12, and 24 months postoperatively. Clinical assessments consisted of the visual analog scale and the Constant score. Radiological evaluation was achieved by measuring the coracoclavicular distance.

RESULTS

The mean follow-up was 35 ± 9 months (range, 24-55 months). The visual analog scale and Constant scores revealed significant improvements from 6 ± 1 (range, 4-8) and 42 ± 4 (range, 35-48) scores preoperatively to 1 ± 1 (range, 0-1) and 94 ± 2 (range, 90-98) scores at the final evaluation, respectively (P < .001). The coracoclavicular distance of the injured side was an average of 9 ± 1 mm (range, 7-12 mm) at the final follow-up radiograph which was not significantly different from that of the contralateral side (P = .75).

CONCLUSIONS

In this study, the triple Endobutton technique was a safe, reliable, and novel surgical technique that yielded good to excellent short-term clinical and radiological outcomes for the treatment of Neer type II distal clavicle fractures.

Coracoid process transfer and distal clavicle resection for chronic acromioclavicular separation

Background

Dewar's procedure for transferring the coracoid process with the short head of biceps and coracobrachialis was reported in 1965 for treatment of both acute and chronic acromioclavicular (AC) joint separation, but little contemporary literature exists around the procedure. We report the clinical results of coracoid process transfer with excision of the lateral end of the clavicle for chronic AC joint separation.

Methods

Fifty-one patients (39 men and 12 women, mean age 46 ± 16 years) were included in the study. Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons and the Japanese Orthopaedic Association scores, as well as by measuring active range of motion in the shoulder, before-after (minimum follow-up time of 24 months [27 ± 3 months]) surgery. Plain radiographs were used to examine stability of the AC joint and bone union of the graft.

Results

The mean American Shoulder and Elbow Surgeons and Japanese Orthopaedic Association scores increased (from 61 ± 14 to 91 ± 6, and from 54 ± 9 to 89 ± 8, respectively) at the time of final follow-up. There were no differences in active elevation and external rotation between before-after operation. Six patients whose grafts were fractured or displaced showed complete or partial loss of reduction of the AC joint.

Conclusion

By transferring the coracoid process, the AC joint regained stability after chronic joint separation. Although potential complications related to the graft still need to be addressed, Dewar's procedure and lateral clavicle resection could be a reliable treatment of chronic AC joint separation.

Acromioclavicular Joint Injury and Repair

The acromioclavicular (AC) joint is commonly injured in athletes participating in contact and overhead throwing sports. Injuries range from simple sprains to complete ligamentous disruption, and they are classified by the established Rockwood grading system. High-grade injuries are associated with fractures around the AC joint and disruption of the superior shoulder suspensory complex, a ring of osseous and ligamentous structures at the superior aspect of the shoulder. Radiographs are the mainstay of imaging of the AC joint, with magnetic resonance imaging reserved for high-grade injuries to aid classification and plan surgical management. Low-grade AC joint injuries tend to be managed conservatively, but a wide range of surgical procedures have been described for higher grade injuries and fractures around the AC joint. This review illustrates the anatomy of the AC joint and surrounding structures, the imaging features of AC joint injury, and the most commonly performed methods of reconstruction and their complications.

Does Weaver-Dunn procedure have a role in chronic acromioclavicular dislocations? A meta-analysis

Background

In treatment of chronic acromioclavicular (AC) joint dislocations, both the Weaver–Dunn procedure (WD) and CC ligament reconstruction (CCR) are recommended options due to the low possibility of healing of the coracoclavicular (CC) ligaments. The aim of this review was to determine whether CCR will yield favorable clinical and radiographic outcomes in the treatment of chronic AC dislocations.

Method

The Cochrane Library, EMBASE, and PubMed databases were searched for literature on chronic AC dislocations from data inception to June 30, 2021. Patient data were pooled using standard meta-analytic approaches. The Cochrane-Mantel–Haenszel method and variance-weighted means were used to analyze the outcomes. The Review Manager version 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) was used to calculate the heterogenicity, mean difference, and relative risk (RR) for all outcomes in the meta-analysis.

Results

The current analysis included four trials on this topic, and all AC joint dislocations were classified as Rockwood types III to VI. The pooled data showed that the CCR group had significantly better post-operative American Shoulder and Elbow Surgeons Shoulder (ASES) scores, Oxford Shoulder Scores (OSSs), and Nottingham Clavicle Scores (NCSs) than the WD group, with a significant difference (p < 0.001, p = 0.020, and p < 0.001, respectively). In terms of the post-operative Constant-Murley Scores (CMSs), there were no significant differences between the CCR group and the WD group (p = 0.100). The CCR group had significantly better post-operative abduction and flexion of the index shoulder than the WD group (p < 0.001 and p < 0.001, respectively). In terms of radiological outcomes, the post-operative coracoclavicular distance (CCD) with a 10 kg load was smaller in the CCR group compared to that in the WD group (p < 0.001). The overall surgical wound infection rate was 11.6% in the WD group and 12.9% in the CCR, respectively (p = 0.82).

Conclusion

The CCR group had better clinical outcome scores in the ASES, OOS, NCS, abduction, flexion, and external rotation than the WD group. In terms of radiological outcomes, the CCR group showed less displacement in weight-loaded post-CCD than the WD group, which indicated that the CCR provided more stability and resistance to deformation forces.

Anatomical versus non-anatomical configuration of double coraco-clavicular tunnel technique in acromioclavicular joint reconstruction

PURPOSE

Horizontal instability is a common problem after acromioclavicular joint injuries. The aim of this study was to evaluate if there is a difference regarding horizontal stability between an anatomical and a non-anatomical configuration of the double tunnel coraco-clavicular ligament reconstruction of the acromioclavicular joint.

METHODS

Thirteen acromioclavicular joints of human cadaveric shoulders in ethanol-glycerin fixation were included in the study and underwent cyclic anterior and posterior translational testing at a load of 70 N using an electromechanical uniaxial testing machine. The shoulders were randomly assigned to the following groups: double coraco-clavicular tunnel technique in an anatomical configuration (DCTa) and double coraco-clavicular tunnel technique in an inverse configuration of the anatomical position (DCTb). The dislocation was recorded with a 3D optical measuring system.

RESULTS

The total horizontal displacement (p₁₀ = 0.0221; p₅₀₀₀ = 0.082) was significantly higher for the non-anatomical reconstruction (DCTb) compared to the anatomical reconstruction (DCTa) after every measured amount of cycles. The increase in displacement for DCTb group was overall higher than the increase in displacement for DCTa group but without significance.

CONCLUSION

Reconstruction of the CC ligaments in an anatomical configuration with two suture devices results in a significantly higher stability of the AC joint in the horizontal plane than reconstruction of the CC ligaments in a non-anatomical configuration. Based on the results of this biomechanical in vitro study, the use of a double coraco-clavicular reconstruction should focus on an anatomically correct position of the suture devices.

Kinematic Alterations in the Shoulder Complex in Rockwood V Acromioclavicular Injuries During Humerothoracic and Scapulothoracic Movements: A Whole-Cadaver Study

BACKGROUND

Previous cadaveric kinematic studies on acromioclavicular injuries described mainly rotational differences during humerothoracic movements. Although isolated scapulothoracic movements are also often performed during activities of daily life and can be painful after acromioclavicular injuries, they have not been extensively studied. Further, the analysis of joint translations in kinematic studies has received little attention compared with biomechanical studies.

HYPOTHESIS

A kinematic analysis of joint motions in the intact shoulder versus a shoulder with Rockwood V injury would demonstrate a different pattern of kinematic alterations during humerothoracic and scapulothoracic movements.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A kinematic analysis was performed in 14 cadaveric shoulders during 3 humerothoracic passive movements (coronal and sagittal plane elevation and horizontal adduction) and 3 scapulothoracic passive movements (protraction, retraction, and shrug). An optical navigation system registered rotational motions in the sternoclavicular, scapulothoracic, and acromioclavicular joints in the intact and Rockwood V conditions. In the acromioclavicular joint, mediolateral, anteroposterior, and superoinferior translations were also analyzed.

RESULTS

In the Rockwood V condition, a significant increase in clavicular elevation in the sternoclavicular joint during both humerothoracic and scapulothoracic movements was demonstrated, whereas a significant decrease in posterior rotation of the clavicle occurred only during humerothoracic movements. In the scapulothoracic joint, the scapular position changed most significantly during protraction. In the acromioclavicular joint, the scapular tilting position was altered significantly during both humerothoracic and scapulothoracic movements, whereas the scapular rotational position changed only during coronal and sagittal plane elevation. The largest significant changes in the scapular protraction position were seen during protraction movement. Further, in the acromioclavicular joint there was a significant inferior translation of the scapula during all motions, a significant anterior translation during protraction and horizontal adduction, and a significant posterior translation during coronal plane elevation. Mediolaterally, the acromial end of the scapula slid further under the distal clavicle during protraction than during horizontal adduction.

CONCLUSION

Large kinematic differences were seen between the intact state and a Rockwood V lesion not only during humerothoracic movements but also during scapulothoracic movements in the cadaveric model. During humerothoracic movements, rotational differences were mainly caused by alterations in the clavicular position. In contrast, during protraction, the alterations in the scapular position were the dominant factor.

CLINICAL RELEVANCE

This study demonstrates that protraction induces larger kinematic alterations than horizontal adduction in acromioclavicular injuries and can therefore be included in both clinical examination and kinematic analyses to identify lesions more clearly.

Biomechanical testing of three coracoclavicular ligament reconstruction techniques with a 3D printing navigation template for clavicle-coracoid drilling

Background

The identification and precise clavicle-coracoid drilling during coracoclavicular (CC) ligament reconstruction for acromioclavicular (AC) joint dislocation require a high level of experience and surgical skills. Furthermore, the improvement of flexible fixation, such as Endobutton techniques for CC ligament reconstructions is ongoing. We have developed a 3D printing technique navigation template for clavicle-coracoid drilling and a novel implant for the reconstruction. This study aimed to determine the efficiency of the navigation template for clavicle-coracoid drilling and to evaluate the biomechanical performance of the novel CC ligament reconstruction technique.

Methods

A total of 24 fresh-frozen human cadaveric shoulders were randomly assigned to 1 of 3 reconstruction groups or a control group: TightRope, Triple Endobutton, and the Adjustable Closed-Loop Double Endobutton technique. Computed tomography scans, navigation template designs, and 3D printing were performed for the shoulders. Then, AC joint dislocation was simulated in the reconstruction groups, and 3 CC ligament reconstruction techniques were operated via the 3D printing template separately. Furthermore, biomechanical protocols including the translation test (load from 5 to 70 N) and the load-to-failure test were performed to characterize the behaviors and strengths. One-way ANOVA test analyzed differences in displacement under the translation load and the load at failure.

Results

CC ligament reconstructions were performed successfully along with the 3D printing navigation template in the 3 reconstruction groups. During the translation test, no significant difference was found in displacements among the 4 groups. Meanwhile, the mean load of all reconstruction groups at failure (Adjustable Closed-Loop Double Endobutton, 722.1620 N; TightRope, 680.4020 N; Triple Endobutton, 868.5762 N) was significantly larger than the control group (564.6264 N, P<0.05). The Triple Endobutton group had the maximum load at failure (P<0.05), however, no significant difference was noticed between the other 2 reconstruction groups (P>0.05).

Conclusions

The 3D printing navigation template may become helpful and reliable for AC joint dislocation surgery. Among the 3 CC ligament reconstruction techniques, the Triple Endobutton technique has the best strength in terms of biomechanics, while the biomechanical strength of the Adjustable Closed-Loop Double Endobutton technique is reliable in comparison with the TightRope technique.

The prevalence of intraarticular associated lesions after acute acromioclavicular joint injuries is 20%. A systematic review and meta-analysis

PURPOSE

To synthesise the evidence on the prevalence of associated intraarticular lesions in subjects with acute acromioclavicular joint (ACJ) dislocations.

METHODS

A search in two electronic databases (PUMBMED and EMBASE) was performed from 1985 to 2019. Two independent reviewers selected studies that complied with the following inclusion criteria: (1) the study included data on surgically treated ACJ dislocation grade III-V in the Rockwood classification, (2) the ACJ injuries were acute (the surgery was performed less than 6 weeks after injury), (3) an arthroscopic evaluation of the glenohumeral joint was performed during surgery. The quality of the studies included was assessed using the tool of the Joanna Briggs Institute.

RESULTS

A total of 47 studies with acute ACJ injuries met the initial inclusion criteria. Of these, 21 studies (9 retrospective case series, 9 prospective case series and 3 retrospective cohort studies) presented data on associated intraarticular lesions amenable for use in the meta-analysis. The meta-analysed studies included a total of 860 subjects with acute ACJ dislocations with a male/female ratio of 6.5 and a mean age of 32 years. The meta-analysis showed a prevalence of associated intraarticular lesions in subjects with acute ACJ of 19.9% (95% confidence interval [CI] 14.0-26.4%; 21 studies, 860 analysed participants; P = 0.000; I²: 74.5% random-effects model; low risk of bias).

CONCLUSION

One in five subjects with surgically treated acute ACJ dislocations will have an associated intraarticular lesion that requires further intervention. The case for a customary arthroscopic evaluation of the joint, even when an open procedure is performed to deal with the ACJ dislocation, is strong. Level of evidence IV Trial registry Systematic review registration number: PROSPERO CRD42018090609.

Allo- and autografts show comparable outcomes in chronic acromioclavicular joint reconstruction: a systematic review

PURPOSE

The aim of this review was to compare clinical and radiological outcome of acromio-clavicular joint reconstruction with allografts versus autografts.

METHODS

The PubMed, MEDLINE, The Cochrane Library and WEB OF SCIENCE databases were searched in accordance with the PRISMA guidelines until February 2020 using the terms: 'coracoclavicular' OR 'coraco-clavicular' OR 'acromioclavicular' OR 'acromio-clavicular joint', AND 'reconstruction'. All studies reporting on clinical and radiological outcome as well as complications after ACJ reconstruction using allo- and/or autografts were included.

RESULTS

A total of 29 articles, including 2 prospective and 27 retrospective studies, involving 622 patients, reconstructed with either allo- (n = 360) or auto-grafts (n = 262), for acromio-clavicular joint instability were identified and included in this review. The majority of studies had low sample sizes (66.7% below n = 20), were retrospective (93.3%), with short-term follow-ups (average 26.2 ± 12.6 months; range 6-186). The study with the largest sample size (n = 128) did not report clinical outcome. A comparison between allo- and auto-graft showed no significant differences regarding age, gender, and follow-up times. Clinical outcome was comparable in both groups, loss of reduction (LOR) and complication rates were higher in the allograft group. Overall a reduction of LOR was shown if additional horizontal stabilization was performed. Also a higher LOR and revision rate was documented in allografts without suture or suture-tape augmentation. The use of more clavicular drill-holes correlated with a higher frequency of fracture.

CONCLUSIONS

A systematic review of the available peer-reviewed literature addressing allograft and autograft reconstruction of unstable coracoclavicular ligaments shows that the published studies are generally of low quality with low levels of evidence. The published literature shows no significant difference in clinical outcomes between the use of autografts or allografts in ACJ reconstruction surgery. Surgical techniques utilizing additional horizontal stabilization may contribute to lower rates of LOR. In cases where allograft tissue is used for ACJ reconstruction the use of suture/tape augmentation may reduce LOR rates as well as revision rates.

LEVEL OF EVIDENCE

III.

Evaluation of the Circles Measurement and the ABC Classification of Acromioclavicular Joint Injuries

BACKGROUND

Acromioclavicular joint (ACJ) injuries are common. Despite this, it remains unclear how best to assess, classify, and manage these cases. A simple, reliable, valid, and accurate radiographic parameter to measure ACJ displacement would allow improved consistency of diagnosis and subsequent treatment pathways.

PURPOSE

To evaluate "the circles measurement" and associated "ABC classification" as a tool for assessing ACJ displacement and injury classification.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The circles measurement is taken from a lateral Alexander radiograph of the shoulder. The measurement is the center-to-center distance between 2 circles drawn to define the lateral extent of the clavicle and the anteromedial extent of the acromion; it is independent of the displacement plane, judging total ACJ displacement in any direction rather than trying to quantify vertical and/or horizontal displacement. When utilized clinically, the circles measurement is a single measurement calculated as the difference between values recorded for the injured and uninjured sides. Validation of the circles measurement was performed using lateral Alexander radiographs (including ±20° projection error in all planes) and computed tomography of standardized ACJ injury simulations. We assessed inter- and intrarater reliability, convergent validity, and discriminant validity of the circles measurement and subsequently generated a classification of ACJ injury based on displacement.

RESULTS

Reliability and validity of the circles measurement was excellent throughout. Interrater reliability (ICC [intraclass correlation coefficient] [2,1], 95% CI; n = 78; 4 observers) was 0.976 (0.964-0.985). Intrarater reliability (ICC [2,1]; 95% CI; n = 78; 2 measures) was 0.998 (0.996-0.998). Convergent validity (Pearson correlation coefficient, r) was 0.970 for ideal radiographs and 0.889 with ±20° projection error in all planes. Discriminant validity, with 1-way analysis of variance, showed a P value of <.0001 and effect size (η²) of 0.960, with the ability to distinguish between the previously defined stable (Rockwood IIIA) and unstable (Rockwood IIIB) injuries. The results permitted objective, statistically sound parameters for the proposed ABC classification system.

CONCLUSION

The circles measurement is a simple, reliable, valid, accurate, and resilient parameter for assessing ACJ displacement and can be used in conjunction with the proposed ABC classification to define ACJ injuries more accurately and objectively than previously described.

CLINICAL RELEVANCE

This novel parameter has the potential to standardize the initial assessment and possibly the subsequent clinical management of ACJ injuries, in addition to providing a standardized measure for future research.

Clinical Outcome of Neer Type II Lateral End Clavicle Fractures With Coracoclavicular Ligament Disruption Treated With Pre-Contoured Locking Plate and Endobutton

Introduction

Many surgical techniques have been described for the treatment of Neer type II lateral end clavicle fractures like open reduction and internal fixation with hook plate, tension band wiring, coracoclavicular screw fixation, and distal clavicle locking plate. However, most of these operative procedures are associated with high perioperative complications ranging from hardware prominence, hardware failure, screw and plate pull-out, and infection. As the lateral end clavicle fractures has both vertical and horizontal stress forces, any technique counteracting both the forces should result in a better clinical outcome. Therefore, this study was conducted to assess the functional and radiological outcome of type II lateral end clavicle fracture treated using pre-contoured locking plate along with coracoclavicular reconstruction with endobutton and fiberwire.

Methods

Thirty-two consecutive patients with Neer type II fractures of the lateral end of clavicle were treated surgically using pre-contoured locking plate and coracoclavicular reconstruction with endobutton and fiberwire between May 2014 and December 2016. Clinical outcome was assessed using the University of California Los Angeles (UCLA) shoulder score and Constant Murley score. The coracoclavicular distance was also recorded. These were compared to the unaffected side at one-year follow-up.

Results

The bony union was achieved in all cases. There were no major complications in any of the patients. All the patients were able to return to their preinjury level of activity. The UCLA score, the Constant Murley score, and coracoclavicular distance did not vary significantly at a one-year interval when compared to the normal shoulder.

Conclusion

Open reduction and internal fixation of Neer type II lateral end clavicle fractures using pre-contoured locking distal clavicle plate along with coracoclavicular reconstruction with endobutton and No. 2 fiberwire provide an excellent functional and radiological outcome.

Anatomic reconstruction of acromioclavicular joint dislocations using allograft and synthetic ligament

Background

Acromioclavicular (AC) separations are commonly seen shoulder injuries. Numerous surgical reconstruction techniques have been described. In this study, we present a series of patients who underwent an anatomic reconstruction using a synthetic ligament and allograft construct.

Methods

We performed a retrospective review of patients with type IV or V AC separations who underwent primary or revision AC reconstruction with a luggage-tag synthetic ligament and a semitendinosus allograft placed through the anatomic insertion sites of the coracoclavicular ligaments. Patient-reported outcomes, as well as complication rates, were recorded at a minimum 2-year follow-up.

Results

Ten patients with a mean age of 44.2 ± 14.9 years were included in the study. The mean Disabilities of the Arm, Shoulder and Hand score was 15.5 ± 15.4; mean Single Assessment Numeric Evaluation score, 81.8 ± 12.1; mean Simple Shoulder Test score, 11.4 ± 1.1; mean American Shoulder and Elbow Surgeons score, 84.6 ± 15.7; mean Constant score, 82.5 ± 11.6; and mean visual analog scale score, 2 ± 2.6.

Conclusion

The technique using a luggage-tag synthetic ligament along with an anatomic allograft coracoclavicular ligament reconstruction is a safe, effective alternative to other techniques described in the literature.

Chronic acromioclavicular dislocations: multidirectional stabilization without grafting

Objective

Clinical and radiological evaluation of the surgical treatment of chronic acromioclavicular (AC) dislocations with triple button device and AC joint augmentation.

Materials and Methods

This retrospective study included 21 patients with chronic AC dislocations. All patients underwent bilateral-weighted Zanca and Alexander views as well as the Constant score (CS) and Acromioclavicular Joint Instability Scoring System (ACJI).

Results

A total of 21 patients (19 men and 2 women) with the mean age of 30.7 ± 11.7 years (range, 19-62 years) were able to participate in clinical and radiographic follow-up. After a mean follow-up of 49.7 ± 17.1 months (range, 13-60 months), the results of the CS were 95.2 ± 5.5 (range, 85-100) and ACJI test 89.7 ± 7.9 (range, 75-100), showing no significant differences with the uninjured shoulder (CS, 96.2 ± 3.9; range, 85-100; ACJI, 95.7 ± 4.1; range, 85-100). At the final review, we observed that the preoperative coracoclavicular distance (Zanca view) improved from 12.8 ± 1.5 mm to 8.5 ± 1.3 mm and the AC distance (Alexander view) from 7.8 ± 2.3 mm to 0.99 ± 0.91 mm. Compared with healthy shoulder, these differences were not significant. Osteoarthritis or radiological calcifications were not associated with worse clinical outcomes.

Conclusion

The triple button device is an acceptable alternative surgical method for chronic AC joint dislocations. The surgical technique is simple; it does not need a graft, nor does it present major complications, and material extraction is unnecessary.

Surgical techniques for management of acromioclavicular joint separations: review and update for radiologists

Imaging plays a central role in the postoperative management of acromioclavicular (AC) joint separations. There are more than 150 described techniques for the surgical management of AC joint injuries. These procedures can be categorized as varying combinations of the following basic techniques: a) soft-tissue repair, b) trans-articular AC joint fixation, c) coracoclavicular (CC) fixation, d) non-anatomic reconstruction of the CC ligaments, e) anatomic reconstruction of the CC ligaments, f) distal clavicle resection, and g) dynamic muscle transfer. The goals of this article are to describe the basic techniques for the surgical management of AC joint separations with an emphasis on technique-specific complications and postoperative imaging assessment.

Surgical management of Rockwood type 3 acromioclavicular joint injuries: a retrospective comparison of outcomes of suture anchor fixation and double-button fixation techniques

The treatment of type 3 acromioclavicular joint injuries has still controversial issues. In this retrospective study, we aimed to compare the radiological and functional outcomes of the suture anchor and double-button fixation methods for the treatment of type 3 acromioclavicular joint injuries.This study included 20 patients who underwent suture anchor (9 patients) and double-button fixations (11 patients) for isolated type 3 acromioclavicular dislocation. Injuries were classified according to the Rockwood Classification System. Coracoclavicular(CC) distances and anterior translation have been measured pre-operatively and at the 12th month follow-up. Functional evaluation was performed using the DASH, and Constant-Murley scores of the patients were recorded at the12th-month follow-up.The mean age of the patients was 37 (22-50) years in Group 1(double-button group) and 39 (24-56) years in Group 2(suture anchor group). All of the patients were male. There was no statistically significant difference between the DASH and Constant-Murley scores of the 2 groups (P > .05). The mean DASH score of the patients evaluated at the postoperative 12th month was 6.65 (0-38.3) in Group 1 and 2.48 (0-4.2) in Group 2. The mean Constant-Murley score of the patients evaluated at the postoperative 12th month was 89,6 (50-98) in Group 1 and 93,6 (90-98) in Group 2. Comparison of the pre- and post-operative CC distances and pre- and post-operative anterior translation distances of both groups revealed that there was no statistically significant difference between groups regarding postoperative CC distances and anterior translation distances (P > .05).Suture anchor and double-button techniques are reliable treatment methods that are not superior to one another and can yield excellent functional outcomes.

[Open reduction and internal fixation for multiple injuries of superior shoulder suspensory complex with coracoid process fracture]

Objective

To investigate the effectiveness of open reduction and internal fixation for multiple injuries of superior shoulder suspensory complex (SSSC) with coracoid process fracture.

Methods

Between January 2014 and October 2018, 22 patients with multiple injuries of SSSC with coracoid process fracture were treated by open reduction and internal fixation. There were 16 males and 6 females, aged from 24 to 72 years with an average age of 36.6 years. There were 10 cases of falling injury, 5 cases of traffic accident injury, and 7 cases of falling from height injury. All of them were fresh closed injuries. The time from injury to operation ranged from 2 to 17 days with an average of 6.9 days. Both X-ray film and CT showed the coracoid process fracture complicated with clavicular fracture in 14 cases, acromioclavicular joint dislocation in 12 cases, and acromioclavicular fracture in 5 cases. There were 14 cases of two places of SSSC, 7 cases of three places of SSSC, and 1 case of four places of SSSC.

Results

All incisions healed in primary stage after operation. All patients were followed up 10-24 months with an average of 14.1 months. X-ray films showed that all fractures healed and the acromioclavicular joint was normal. The healing time ranged from 6 to 12 months, with an average of 6.2 months. No complications such as internal fixation failure and nonunion occurred. According to University of California Los Angeles (UCLA) shoulder scoring system, the shoulder joint function was rated as excellent in 15 cases, good in 5 cases, and poor in 2 cases at last follow-up. The excellent and good rate was 90.9%.

Conclusion

Open reduction and internal fixation for treatment of multiple injuries of SSSC with coracoid process fracture is firm and reliable. Combined with active postoperative rehabilitation program intervention, it can accelerate the recovery of shoulder joint function and achieve satisfactory effectiveness.

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.

Evaluation of the Clavicle Hook Plate for Treatment of Acromioclavicular Joint Dislocation: A Cadaveric Study

OBJECTIVES

To describe surgical technique for proper placement of the clavicle hook plate, determine whether there is subacromial impingement caused by hook plate fixation, and evaluate the mechanical strength of the clavicle hook plate construct.

METHODS

Eight fresh-frozen cadaveric shoulders with a mean age of 48 years (range, 37-69) were used. Open reduction and internal fixation of simulated Rockwood type V AC joint dislocation was performed with the clavicle hook plate. Three-dimensional computed tomography studies and arthroscopic evaluation were performed with the glenohumeral joint in different orientations to assess the position of the hook plate relative to relevant joint structures. The clavicle was then superiorly loaded to mechanical failure.

RESULTS

Computed tomography evaluations showed no contact between the humerus and the hook plate. Distance between the greater tuberosity and hook plate ranged from 14 to 31 mm with maximal shoulder forward flexion and 8.1-25.4 mm with maximal shoulder abduction. Arthroscopic evaluation of the subacromial space demonstrated that with maximal abduction/forward flexion, there was abutment of the rotator cuff with the hook plate in 6 of 8 specimens. In mechanical testing, mean failure load was determined to be 1011 N (range, 380-1563 N). Failure mechanisms included acromion fracture (4), slippage of the hook under acromion (3), and distal clavicle fracture (1).

CONCLUSIONS

This study demonstrates that the clavicle hook plate reduces AC joint dislocation or distal clavicle fractures anatomically, has supra-physiologic mechanical strength, does not cause bony impingement, and exhibits rotator cuff impingement only with maximal abduction/forward flexion of the shoulder.

Biomechanical evaluation of acromioclavicular joint reconstructions using a 3-dimensional model based on the finite element method

BACKGROUND

This study aims to evaluate the influence of stabilization of acromioclavicular (AC) joint dislocation through the modified Weaver-Dunn technique and coracoclavicular (CC) ligaments using the finite element method. The goal is to determine which surgical technique allows behavior that is most similar to the joint, guaranteeing the necessary stability without restricting joint movements for the considered conditions.

METHODS

The analysis is based on the three-dimensional finite element models. The control group of this study is represented by a three-dimensional model of the whole structure based on finite element methods.

FINDINGS

The finite element models showed the stress and displacement values found in the intact acromioclavicular joint and surgical procedures. It was concluded that transferring the coracoacromial ligament to stabilize the acromioclavicular joint did not have a positive impact on the outcome.

INTERPRETATION

The finite element analysis on the treatment of acromioclavicular dislocation presented here provides medical teams with new parameters for choosing a suitable surgical procedure in the occurrence of acromioclavicular dislocation. The development and validation of the finite element models allow the variation of the conditions and enables different surgical configurations to be simulated.

Current Concepts in the Operative Management of Acromioclavicular Dislocations: A Systematic Review and Meta-analysis of Operative Techniques

BACKGROUND

Acromioclavicular (AC) instability is a frequent injury affecting young and athletic populations. Symptomatic, high-grade dislocations may be managed by a myriad of operative techniques that utilize different grafts to achieve reduction. Comparative data are lacking on the ability of these techniques to achieve excellent patient outcomes and stable AC reduction and to minimize complications.

PURPOSE

To systematically review the outcomes and complications of different techniques of AC joint reconstruction.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The MEDLINE, Scopus, Embase, and Cochrane Library databases were accessed to perform a systematic review of the scientific literature from 2000 to 2018 using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following keywords: "acromioclavicular" and "reconstruction." Included articles were evaluated for loss of reduction, complication rate, revision rate, and change in coracoclavicular distance. Articles were stratified by graft and surgical material used: suture only, Endobutton with suture, TightRope, GraftRope, synthetic artificial ligament, tendon graft, and Weaver-Dunn coracoacromial ligament transfer. These outcomes were pooled using a random-effects model and stratified by surgical technique and arthroscopic versus open reconstruction.

RESULTS

Fifty-eight articles were included in the analysis, with 63 homogeneous populations composed of 1704 patients. The mean age was 37.1 years (range, 15-80 years) with a mean follow-up of 34.3 months (range, 1.5-186 months). The overall failure rate was 20.8% (95% CI, 16.9%-25.2%). The overall pooled complication rate was 14.2% (95% CI, 10.5%-18.8%). The most common complications were infection (6.3% [95% CI, 4.7%-8.2%]), fracture to the coracoid or distal clavicle (5.7% [95% CI, 4.3%-7.6%]), and hardware/button failure (4.2% [95% CI, 3.1%-5.8%]). There were no differences between arthroscopic and open techniques in regard to loss of reduction (P = .858), overall complication rate (P = .774), and revision rate (P = .390). Open surgery had a greater rate of clavicular/coracoid fractures than arthroscopic surgery (P = .048). Heterogeneity, best assessed from the pooled loss of reduction, was measured as I² = 64.0%.

CONCLUSION

Open and arthroscopic AC joint reconstruction techniques have no differences in loss of reduction, the complication rate, and the revision rate based on the available literature. Complications are significant, and profiles vary between surgical techniques, which should be evaluated in the decision making of selecting the technique.

Mechanical Study of the Properties of Sutures used in Orthopedics Surgeries

Objective  To evaluate the mechanical properties of sutures commonly used in orthopedic surgeries, characterizing their behavior through tensile tests and determining which one has greater mechanical strength.

Method  Tensile tests of different sutures were performed in a mechanical testing machine BME 10 kN, using a 50 kgf maximum capacity loading cell. Seven samples from each suture material were tested. Both ends of the sample material were fixed in the proper metal claw, maintaining an initial length of 5 cm. Tests were performed at a speed of 20 mm/minute and at room temperature, recording data for maximum displacement and maximum force at the rupture point.

Results  FiberWire® #2 (Artrhex, Naples, FL, USA) presented the highest mean strength of rupture (240.17 N), followed by HiFi® #2 (Conmed, Utica, NY, USA) (213.39N) and Ethibond® #5 (Ethicon Inc., Somerville, NJ, USA) (207.38 N). Ethibond® #2 (Ethicon Inc., Somerville, NJ, USA) had the lowest mean strength of rupture (97.8 N).

Conclusion  Non-absorbable braided polyblend sutures, more recently introduced, are superior to conventional, braided polyester sutures, and FiberWire® #2 is the most resistant suture evaluated in the present study.

Three intrasubstance failures of a LARS™ ligament used for ligament reconstruction

We report three cases of intrasubstance failure of a LARS™ (Ligament Augmentation and Reconstruction System) artificial ligament used for acromioclavicular joint reconstruction. The LARS™ ligament failed within four months of the index procedure. All patients underwent a revision procedure following an unsuccessful trial of conservative management. A modified second loop technique was employed during the revision procedure for all cases using the LARS™ ligament. All three patients achieved full recovery to pre-injury level function.

Current concepts in management of ACJ injuries

Acromioclavicular joint injury is common in young individuals who suffer direct trauma to the shoulder. Treatment of acromioclavicular dislocation is controversial with regards to the indication of operative management, timing of surgery, whether to perform open or arthroscopic surgery, method of stabilisation (rigid or non-rigid) and type of graft used for repair or reconstruction. Current evidence supports conservative management for Rockwood types I and II, while types IV, V and VI benefit from surgery. The optimal management of type III injuries in high demand patients remains contentious. Surgical options include acromioclavicular fixation, coracoclavicular fixation and coracoclavicular ligament reconstruction. Few studies with a low level of evidence suggest arthroscopic techniques and anatomical ligament reconstruction have better outcomes when compared to older techniques of rigid coracoclavicular fixation. The aim of this article is to look at the current evidence and address these controversial issues.

A Modified Weaver-Dunn Procedure with or without Chip Bone Graft for the Treatment of Acromioclavicular Joint Separation

BACKGROUND

In spite of frequent injuries to the acromioclavicular (AC) joint, there is no consensus regarding optimal technique to be used. This cohort study evaluated the clinical results of a modified Weaver-Dunn procedure with or without chip bone graft for the treatment of AC joint separation retrospectively.

MATERIALS AND METHODS

60 consecutive patients with AC joint separation, between the age of 19-76 years (mean age 43 years), were enrolled between January 2005 and September 2011. Forty patients (35 men, 5 women) were treated with a modified Weaver-Dunn procedure, and did not receive bone graft during the procedure (Group 1), whereas twenty patients (19 men, 1 woman) received autogenous chip bone graft (Group 2). Stability of the AC joint was evaluated clinically and radiographically, and the clinical results were assessed by the Imatani evaluation system.

RESULTS

The mean duration of followup was 2 years and 2 months. The results were excellent in all patients except one. At final followup, roentgenographic measurement revealed that the mean coracoclavicular interval was 8.2 mm on the affected side, and 8.9 mm on the unaffected side in Group 1, and 9.5 mm on the affected side and 10.1 mm on the unaffected side in Group 2. For Group 1, there were significant differences between augmentation of the grafted coracoacromial (CA) ligament antero-posteriorly and laterally (Option B) and repair of the torn AC ligament with augmentation of the grafted CA ligament antero-inferiorly (option A; P = 0.0351).

CONCLUSIONS

The modified Weaver-Dunn procedure (Group 1 and 2) provides a stable and strong reconstruction for the treatment of AC joint separation. In addition, this modified Weaver-Dunn procedure with chip bone graft (Group 2) may lead to same or more secure healing of the grafted CA ligament-bone than the same procedure without chip bone graft (P = 0.9737).

Open Anatomic Coracoclavicular Ligament Reconstruction by Modified Conjoint Tendon Transfer for Treatment of Acute High-Grade Acromioclavicular Dislocation

There is no ideal surgical technique for the treatment of acromioclavicular (AC) dislocations. Reconstruction of the coracoclavicular ligaments (CCLs) for the treatment of AC dislocations is evolving. Many techniques for CCL reconstruction have been described. They differ mainly in the method of fixation, number of tunnels, and graft used. The surgeon should select among hamstring autograft reconstruction, coracoacromial ligament transfer, and conjoint tendon transfer for CCL reconstruction. Early on, conjoint tendon transfer to the lateral clavicle was described for the treatment of high-grade AC dislocation. Dynamic instability occurred with poor long-term outcomes. The procedure was abandoned. Recently, proximally based conjoint tendon transfer for CCL reconstruction was described, but the technique is nonanatomic and leads to anterior displacement of the clavicle and malreduction. This article describes modified conjoint tendon transfer. The technique may yield stable, anatomic, biological reconstruction of the CCL for the treatment of acute high-grade AC dislocation. It consists of the following steps: (1) creation of clavicular holes, (2) coracoid osteotomy, (3) conjoint tendon mobilization, (4) conjoint tendon transfer and fixation to the CCL footprint on the undersurface of the clavicle, and (5) AC reduction and conjoint tendon tenodesis to the bed of the retained coracoid process.

Surgical reconstruction of the acromioclavicular joint: Can we identify the optimal approach?

Injuries to the acromioclavicular (AC) joint are common, tending to occur secondary to traumatic injuries. Rockwood grade IV, V and VI injuries involve complete dislocation of the joint and require surgical reconstruction, with inconclusive literature on whether grade III injuries should be surgically or conservatively managed. There are over one hundred reported surgical techniques which reconstruct the AC joint, with little indication of which methods achieve the best results. Techniques can generally be considered as: anatomical reduction; CC ligament reconstruction; and anatomical reconstruction. Techniques which implant hardware to reduce the AC joint, such as the hook plate, are commonly implemented, but have been shown to alter the mechanics of the joint significantly, resulting in poor short-term and long-term outcomes. Methods which reconstruct both the acromioclavicular and coracoclavicular ligaments are comparatively new, and early reports suggest that they achieve biomechanical properties similar to the native joint. More focus should be placed on such techniques in the future to determine whether they offer a more suitable approach to improve patient outcomes following AC joint reconstruction.

Treatment of AC dislocation by reconstructing CC and AC ligaments with allogenic tendons compared with hook plates

BACKGROUND

The purpose of this study was to compare outcomes between allograft reconstruction and hook plate fixation for acute dislocation of the acromioclavicular joint with a minimum 2-year follow-up.

METHODS

A retrospective comparative study of patients treated for acute acromioclavicular joint dislocation from February 2010 to December 2014 in our hospital, consisting of 16 patients who were followed-up, was performed. Eight patients were treated for acute AC dislocation and underwent surgical reconstruction as follows: the coracoclavicular and acromioclavicular ligaments were reconstructed with the allogenic tendon. The other eight patients were treated with hook plates to maintain the AC joint reset. At the latest follow-up, radiographic analysis and the Constant and University of California-Los Angeles (UCLA) scores were used to evaluate shoulder function. The satisfaction of the patients in terms of the efficacy and visual analog scale (VAS) data were also recorded.

RESULTS

After an average follow-up of 30.3 months (range 24-46 months), no patient had dislocated their joint again at the final follow-up based on X-ray examination. The Constant score was 94.4 for the allogenic tendon group and 93.8 for the hook plate group (P = 0.57). According to the UCLA scale (P = 0.23) or VAS (P = 0.16), we found no significant difference between the two groups. All patients reported that they were very satisfied or satisfied with the outcome of surgery, and no significant difference (P = 0.08) was found between the two groups.

CONCLUSIONS

The use of allogenic tendon for reconstruction of the coracoclavicular and acromioclavicular ligaments shows excellent outcomes in terms of the recovery of clinical function or radiographic outcomes for acute AC dislocation. Compared with the hook plate, the hardware did not need to be removed.

Biomechanical Comparison of Anatomic and Extra-Anatomic Reconstruction Techniques Using Local Grafts for Chronic Instability of the Acromioclavicular Joint

BACKGROUND

Anatomic reconstruction techniques are increasingly used to address cases of acromioclavicular (AC) joint chronic instability. These usually involve an additional surgical site for autograft harvesting or an allograft.

PURPOSE

To describe a triple-bundle (TB) anatomic reconstruction using on-site autografts, the semiconjoint tendon (SCT) and the coracoacromial ligament (CAL), and compare its primary stability to the native AC joint ligamentous complex and to a modified Weaver-Dunn (WD) reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Intact AC joints of 12 paired cadaveric shoulders were tested for anterior, posterior, and superior translations under cyclic loading with a servo-hydraulic testing system. One shoulder from each pair was randomly assigned to the TB group, where 2 SCT strips were used to reconstruct the coracoclavicular ligaments while the distal end of the CAL was transferred to the distal extremity of the clavicle to reconstruct the AC ligaments; the other shoulder received a modified WD reconstruction. After reconstruction, the same translational testing was performed, with an additional load-to-failure test in the superior direction.

RESULTS

In both the TB and the WD groups, no significant differences were found before and after reconstruction in terms of joint displacements after cyclic loading, in all 3 directions. Compared with the WD reconstruction, the TB repair resulted in significantly lower displacements in both the anterior (ie, 2.59 ± 1.08 mm, P = .011) and posterior (ie, 10.17 ± 6.24 mm, P = .014) directions, but not in the superior direction. No significant differences were observed between the 2 reconstructions during the load-to-failure testing, except for the displacement to failure, which was significantly smaller (ie, 5.34 ± 2.97 mm) in the WD group ( P = .037).

CONCLUSION

Anterior, posterior, and superior displacements after an anatomic reconstruction of the AC joint complex using the SCT and CAL as graft material were similar to those of native AC joints and significantly smaller in the axial plane than those of AC joints after a WD repair.

CLINICAL RELEVANCE

An anatomic reconstruction is achievable using the CAL and the SCT as on-site graft materials, providing satisfactory initial stability and thereby allowing earlier mobilization.

A prospective study of coracoclavicular ligament reconstruction with autogenous peroneus longus tendon for acromioclavicular joint dislocations

BACKGROUND

Anatomic coracoclavicular (CC) ligament reconstruction (ACCR) provides good outcomes for Rockwood type III and VI acromioclavicular (AC) joint dislocations. Various grafts have been used, but complications from graft harvesting are not uncommon. This study examined the clinical and radiographic outcomes of patients with AC joint dislocations repaired with the autogenous anterior half of the peroneus longus tendon (AHPLT) to achieve ACCR.

METHODS

Patients with a Rockwood type III to V AC joint dislocation and magnetic resonance imaging of the disruption of the CC ligaments, as well as the AC capsule, were prospectively recruited. Patients received ACCR using an autogenous AHPLT graft and were evaluated clinically and radiographically preoperatively and at 1, 3, 6, and 12 months postoperatively.

RESULTS

A total of 18 patients (mean age, 51 years) were prospectively recruited and received an autogenous AHPLT graft ACCR. Fifteen patients completed clinical and radiographic follow-up examinations at 12 months. The mean Constant score (CS) was 51 preoperatively and 93 at 12 months (P <.005). No significant difference was noted at 12 months between the CS of the injured and contralateral shoulder. The mean American Orthopedic Foot and Ankle Society score at 12 months was 99, and this was not different from the value at any other time point. Loss of reduction occurred in 10 patients (56%), and tunnel widening was observed in 9 (50%), but neither was significantly correlated with functional outcome.

CONCLUSION

Autogenous AHPLT appears to be a reliable tendon graft source for CC ligament reconstruction.

Shoulder Acromioclavicular and Coracoclavicular Ligament Injuries: Common Problems and Solutions

Injuries to the acromioclavicular joint and coracoclavicular ligaments are common. Many of these injuries heal with nonoperative management. However, more severe injuries may lead to continued pain and shoulder dysfunction. In these patients, surgical techniques have been described to reconstruct the function of the coracoclavicular ligaments to provide stable relationship between the clavicle and scapula. These surgeries have been fraught with high complication rates including clavicle and coracoid fractures, infection, loss of reduction and fixation, hardware migration, and osteolysis. This article reviews common acromioclavicular and coracoclavicular repair and reconstruction techniques and associated complications, and provides recommendations for prevention and management.

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

OBJECTIVE

The aim of this study was to compare the long-term clinical and radiological results of Acromioclavicular (AC) fixation with K-wires (the modified Phemister procedure) and Coracoclavicular (CC) fixation with the Bosworth screw in the surgical treatment of Type 3 AC joint dislocations.

METHODS

Thirty-two patients with complete set of medical records and who received surgical treatment between September 2005 and January 2009 due to acute Rockwood Type 3 AC joint dislocation and properly attended their follow-ups were retrospectively evaluated. Sixteen patients (13 males, 3 females; mean age: 38, range: 24-52 years) were treated with CC fixation with Bosworth screw (Group 1), and the other 16 (12 males, 4 females; mean age: 53.3, range: 38-64 years) with AC fixation using K-wires (Group 2).

RESULTS

The mean follow-up time was 96 months for Group 1 and 93 months for Group 2 patients (p > 0.05). The mean Constant-Murley score at the final follow-up was 84.7 in Group 1 and 87.3 in Group 2 (p = 0.069). Radiological evaluation of the patients revealed AC arthrosis in 2 and 3 patients in Group 1 and 2, respectively. In Group 2, one patient had a recurrent dislocation, three patients had AC arthrosis and two patients had ossification in the CC ligament (Fig. 2). There was no superficial or deep wound infection in Group 1, while two patients from Group 2 had a superficial wound infection.

CONCLUSIONS

Our results suggest that both techniques are reliable and provide adequate reduction and similar outcomes in terms of functionality and pain levels, following the reduction of Type 3 AC joint dislocations. With lower rates of wound site infection in the early and AC arthrosis in the late postoperative period, CC fixation method with the Bosworth screw may be a better surgical option than AC fixation method with K-wires.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Ligament Augmentation and Reconstruction System Failures in Repair of Grade V Acromioclavicular Joint Dislocation

The Ligament Augmentation and Reconstruction System® (LARS®) represents a popular synthetic anatomical reduction method for acromioclavicular joint dislocation by means of coracoclavicular ligament reconstruction. To our knowledge, no early failure has been documented in the literature. We present two unusual cases of LARS failure, one at four months after implant and the other at three weeks, without obvious causes, requiring re-do reconstruction, and discuss potential contributory factors.

Anatomic Coracoclavicular Ligament Reconstruction for the Treatment of Acute Acromioclavicular Joint Dislocation: Minimum 10-Year Follow-up

Background:

The long-term clinical and radiographic outcomes following coracoclavicular (CC) ligament reconstruction for the operative treatment of acute acromioclavicular (AC) joint dislocation remain uncertain. The purpose of the present study was to determine the long-term clinical and radiographic outcomes of CC ligament reconstruction and to identify risk factors for unfavorable outcomes.

Methods:

We reviewed 20 cases of AC joint dislocation in 19 patients (18 male and 1 female; mean age, 32.3 years) that were treated with single-bundle reconstruction. The mean duration of follow-up was 12.7 years. We measured the CC vertical distance (CCD) on the anteroposterior view and compared the affected and unaffected sides (CCD ratio). We divided the patients into those with a CCD ratio of <25% (Group 1) and those with a CCD ratio of ≥25% (Group 2). We radiographically investigated the clavicular tunnel anteroposterior (CTAP) angle, clavicular tunnel ratio, and coracoid tunnel orientation on the basis of the entry and exit points at the base of the coracoid. For the coracoid tunnel orientation, we compared center-center orientation and noncenter-center orientation.

Results:

Group 1 comprised 17 cases (85%), and Group 2 comprised 3 cases (15%). At the time of the latest follow-up, Group 1 had a significantly higher mean Constant score than Group 2 (98.2 compared with 90.7; p = 0.038). Of the 3 radiographic parameters, only the CTAP angle was significantly different between the 2 groups (p < 0.0001). Two (67%) of the 3 cases in Group 2 were associated with posterior AC joint displacement.

Conclusions:

CC ligament reconstruction for the treatment of acute AC joint dislocation resulted in successful long-term clinical and radiographic outcomes. It is important to decrease the CTAP angle and to ensure proper anatomic placement of the clavicular and coracoid tunnels at the time of surgery.

Level of Evidence:

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

Anatomical Evaluation of the Proximity of Neurovascular Structures During Arthroscopically Assisted Acromioclavicular Joint Reconstruction: A Cadaveric Pilot Study

PURPOSE

The purpose of this study was to examine the safety of an arthroscopic technique for acromioclavicular joint (ACJ) reconstruction by investigating its proximity to important neurovascular structures.

METHODS

Six shoulders from 4 cadaveric specimens were used for ACJ reconstruction in this study. The procedure consists of performing an arthroscopic acromioclavicular (AC) reduction with a double button construct, followed by coracoclavicular ligament reconstruction without drilling clavicular tunnels. Shoulders were subsequently dissected in order to identify and measure distances to adjacent neurovascular structures.

RESULTS

The suprascapular artery and nerve were the closest neurovascular structures to implanted materials. The mean distances were 8.2 (standard deviation [SD] = 3.6) mm to the suprascapular nerve and 5.6 (SD = 4.2) mm to the suprascapular artery. The mean distance of the suprascapular nerve from implants was found to be greater than 5 mm (P = .040), while the distance to the suprascapular artery was not (P > .5). Neither difference was statistically significant (P = .80 for artery; P = .08 for nerve).

CONCLUSIONS

Mini-open, arthroscopically assisted ACJ reconstruction safely avoids the surrounding nerves, with no observed damage to any neurovascular structures including the suprascapular nerve and artery, and may be a viable alternative to open techniques. However, surgeons must remain cognizant of possible close proximity to the suprascapular artery.

CLINICAL RELEVANCE

This study represents an evaluation of the safety and feasibility of a minimally invasive ACJ reconstruction as it relates to the proximity of neurovascular structures.

Axial-Plane Biomechanical Evaluation of 2 Suspensory Cortical Button Fixation Constructs for Acromioclavicular Joint Reconstruction

BACKGROUND

Although numerous suture-button fixation techniques for acromioclavicular (AC) joint reconstruction have been validated with biomechanical testing in the superior direction, clinical reports continue to demonstrate high rates of construct slippage and breakage.

PURPOSE

To compare the stability of a novel closed-loop double Endobutton construct with a commercially available cortical button system in both the axial and superior directions.

STUDY DESIGN

Controlled laboratory study.

METHODS

Six matched pairs of fresh-frozen cadaveric upper extremities were anatomically dissected and prepared to simulate a complete AC joint dislocation. One side of each pair was reconstructed with the double Endobutton (DE) construct and other side with the dog bone button (DB) construct. The specimens were then tested using a materials testing machine, determining initial superior and axial displacements with a preload, and then cyclically loaded in the axial direction with 70 N for 5000 cycles. Displacement was again measured with the same preloads at fixed cycle intervals. The specimens were then loaded superiorly to failure.

RESULTS

At 5000 cycles, the mean axial displacement was 1.7 mm for the DB group and 1.2 mm for the DE group (P = .19), and the mean superior displacement was 1.1 mm for the DB group and 0.7 mm for the DE group (P = .32). Load at failure was similar (558 N for DE, 552 N for DB; P = .96). There was no statistically significant difference in the modes of failure.

CONCLUSION

Biomechanical testing of both constructs showed similar fixation stability after cyclical axial loading and similar loads to failure.

CLINICAL RELEVANCE

The strength of both constructs after cyclical loading in the axial plane and load-to-failure testing in the superior plane validate their continued clinical use for achieving stability in AC joint reconstruction procedures.

Treatment of distal-third clavicular fractures (Neer type ii-b) with a triple button device

OBJECTIVE

The purpose of this study is to describe the outcomes of using a triple button device for the treatment of displaced distal-third clavicle fractures (Neer, type ii-b).

MATERIAL AND METHOD

A retrospective review was conducted on a series of patients between November 2011 and December 2014. Fourteen patients initially met the inclusion criteria, but 2 were excluded, leaving 12 patients (83.3% male; mean age 32.2 years) for the final analysis at a mean follow-up of 26±11.24 months (range, 12-48). Post-operative follow-up was performed at 2 weeks (two first months), and monthly thereafter, until was achieving clinically and radiological healing. The functional outcome was evaluated using the Constant score, and DASH score in the last follow-up.

RESULTS

The mean Constant Score was 95.5±5.2 points (range, 85-100), with a mean DASH score of 3.3±4.4 points (range, 0-12.5). The mean time to clinical healing was10.3±3.1 weeks (range, 8-16), and the mean time to radiological healing was 13.6±2.6 weeks (range, 12-20). There were no major complications. There were 5 minor complications without clinical impact: 2 coracoclavicular calcifications, 1 hypertrophic scar, 1 patient with discomfort due to the device, and 1 superficial wound infection. All patients returned their previous activity.

CONCLUSION

Good clinical results can be achieved with the triple button device in unstable distal fractures of the clavicle, without the need to remove the hardware.

Midterm results of coracoclavicular stabilization with double augmentation for acute acromioclavicular dislocation

Introduction

Numerous techniques have been introduced for the treatment of acute acromioclavicular (AC) joint dislocation. We aim to report the midterm results of coracoclavicular (CC) stabilization with double augmentation for the acute AC joint dislocation.

Case description

Forty-three patients who underwent surgery for acute AC joint dislocation were followed up for an average of 59.6 months (range 40–97). The study composed of two treatment groups: group S, with 25 patients, in whom two suture anchors were used; and group B, with 18 patients, in whom a suture anchor and a double flip-button device were used, however the techniques in both groups are based on the same principle which is double augmentation. Postoperative evaluations were made retrospectively, clinically, and radiographically.

Discussion and Evaluation

At the last follow-up, the mean Constant score was 91.2 (range 74–100) and the UCLA scale was 31.4 (range 24–35). The overall ratio of the CC distance in the injured shoulder to that in the uninjured shoulder, expressed as a percentage, significantly decreased, to 93.4 ± 22.7 %, immediate postoperatively, and significantly increased, to 113.8 ± 23.4 %, at the final follow-up. Complete reduction of the AC joint was achieved in 34 patients (79.1 %), and 8 patients (18.6 %) exhibited a slight loss of reduction, although their functional outcomes were good.

Conclusions

The results of this study provide evidence that double augmentation is effective in the treatment of acute AC dislocation.

Level of evidence

Therapeutic study, case series, Level IV.

Shoulder acromioclavicular joint reconstruction options and outcomes

Acromioclavicular joint separations are a common cause of shoulder pain in the young athletic population. In high-grade injuries, acromioclavicular joint reconstruction procedures may be indicated for functional improvement. There is currently no gold standard for the surgical management of these injuries. Multiple reconstructive options exist, including coracoclavicular screws, hook plates, endobutton coracoclavicular fixations, and anatomic ligament reconstructions with tendon grafts. This article aims to review pertinent acromioclavicular joint anatomy and biomechanics, radiographic evaluation, classification system, as well as reconstruction options, outcomes, and complications.

A biomechanical assessment of a novel double endobutton technique versus a coracoid cerclage sling for acromioclavicular and coracoclavicular injuries

PURPOSE

Recently, many acromioclavicular-coracoclavicular (AC-CC) ligament reconstruction techniques address only the CC ligament. However, many of these techniques are costly, time-consuming, and require the use of allogenic grafts, making them prone to creep and failure or novel devices making them challenging for orthopaedic surgeons. The purpose of this study was to compare the biomechanical characteristics of a double endobutton technique using a standard endobutton CL with those of a coracoid cerclage sling (CS) for reconstruction of the CC ligaments.

METHODS

Anterior-posterior (AP) translation and superior-inferior (SI) translation were quantified for eight matched pairs of intact AC joints. One shoulder from each pair underwent a double endobutton repair, using an endobutton CL modified with an additional endobutton (Smith & Nephew, Memphis, Tenn) and placed through holes in the coracoid and clavicle. The contra-lateral shoulder received a coracoid sling reconstruction using an anterior tibialis tendon. Translation testing was repeated after reconstruction, followed by load-to-failure testing. Paired t tests were used for statistical analysis.

RESULTS

The CS technique demonstrated a greater SI and AP translation than the double endobutton technique (p < 0.05). Additionally, the double endobutton technique had a greater stiffness (40.2 ± 11.0 vs. 20.3 ± 6.4 N/mm, p = 0.005), yield load (168.5 ± 11.0 vs. 86.8 ± 22.9 N, p = 0.002), and ultimate load (504.4 ± 199.7 vs. 213.2 ± 103.4 N, p = 0.026) when compared to the CS technique.

CONCLUSION

The double endobutton technique yielded less translation about the AC joint and displayed stronger load-to-failure characteristics than the CS reconstruction. As such, this technique may be better suited to restore native AC-CC biomechanics, reduce post-operative pain, and prevent recurrent subluxation and dislocation than an allogenic graft construct. The double endobutton technique may be a suitable option for addressing AC-CC injuries.