Clinical outcomes of a single-tunnel technique for coracoclavicular and acromioclavicular ligament reconstruction

Arthroscopy-assisted procedure provides less residual horizontal instability and optimal coracoid tunnel creation with less radiation exposure compared to percutaneous procedure after endo-button fixation of type III AC joint dislocations

PURPOSE

The aim of this study was to evaluate the postoperative radiological and functional results of patients treated with arthroscopy-assisted (AA) and percutaneous (P) procedures using endo-button for type III acromioclavicular joint dislocations with a minimum 1-year follow-up. The study hypothesis was that the AA technique would provide more favourable coracoid tunnels.

METHODS

This retrospective study included patients who underwent surgery between 2017 and 2022. Computed tomography images taken immediately postoperatively of all the patients were analysed to group coracoid tunnels as optimal or suboptimal based on orientation and placement within the coracoid base. Residual horizontal instability was assessed using the bilateral Alexander view at the final follow-up. Shoulder functions were evaluated at the final follow-up examination.

RESULTS

Of the 63 patients, 39 underwent surgery using the percutaneous procedure and 24 with the AA procedure. Surgical duration was significantly longer in the AA group (AA: 61.1 ± 5.9 min; P: 34.7 ± 5.6 min) (p = 0.001; 95% confidence interval [CI]: 23.3-29.3), whereas fluoroscopy time was longer in the percutaneous group (AA: 2.0 ± 0.8 s; P: 15.7 ± 3.9 s) (p = 0.001; 95% CI: -14.9 to 12.3). Optimal coracoid tunnels were more frequently observed in the AA group (p = 0.001; 95% CI: 7.4-137.8). There was no significant difference in functional scores between the groups (n.s.). Postoperative horizontal instability was more common in the percutaneous procedure (p = 0.013; 95% CI: 8.3-39.2).

CONCLUSIONS

Although no difference was detected between the methods in terms of complications and functional results, the higher frequency of residual horizontal instability, the high risk of suboptimal tunnel creation and greater radiation exposure were seen to be the most important disadvantages of the percutaneous technique. During surgery, such technical problems related to the percutaneous method should be kept in mind and care should be taken about the orientation of the coracoid tunnel.

LEVEL OF EVIDENCE

Level III.

Anatomical acromioclavicular joint stabilization with chemically sterilized tendon allografts: A retrospective study

Background

The purpose of this retrospective study was to analyze whether chemically sterilized tendon allografts perform as well as other non-sterilized allografts and autografts as described in the literature for anatomical acromioclavicular joint stabilization for the treatment of Rockwood III-V. Allografts are still described as a factor for higher re-rupture rates.

Methods

Retrospective data were collected from 21 acromioclavicular joint stabilizations performed by a single surgeon and performed between 2011 and 2014 using sterilized semitendinosus allografts. The primary endpoints were re-rupture and complication rates. Secondary endpoints were AC-joint stability, pain level, return to work and sport and the range of motion.

Results

No re-ruptures occurred during the mean follow-up time of 33 months. Zero complications occurred directly after surgery, but three complications later than three weeks after surgery. All cases resolved without further surgery. After surgery, stability significantly improved for all patients. Post-surgery, 19 patients had stable acromioclavicular joints and only two patients showed minor instabilities. Range of motion returned to the range of the healthy shoulders for all patients.

Conclusion

Chemically sterilized semitendinosus allograft use for anatomic AC-joint stabilization is equivalent to the use of other allografts or autografts and required no hardware removal. No donor age or graft size dependence was observed, due to zero re-ruptures.

Surgical management of acute, high-grade acromioclavicular joint separations: a systematic review

Background

While a number of treatment options exist for repair of acute, high-grade acromioclavicular joint (ACJ) separation, none have emerged as the standard of care. The purpose of this study was to systematically review the literature on surgical treatment of acute, high-grade (Rockwood grades III-V) ACJ separations in order to compare outcomes between direct fixation and tendon graft ligament reconstruction.

Methods

A systematic review of the literature evaluating outcomes for acute ACJ separation treatment with direct fixation or free biologic tendon graft reconstruction was performed. The following databases were examined: the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (1980-2021), and Embase (1980-2021). Studies were included if they reported a mean time to surgery as <6 weeks, contained >10 patients with a minimum 1-year follow-up, and reported clinical or radiographic outcomes.

Results

A total of 52 studies met the inclusion criteria. Seven studies reported outcomes following tendon graft ligament reconstruction (n = 128 patients). There were multiple methods of direct fixation. Thirty-three studies utilized suture button constructs (n = 1138), 16 studies used hook plates (n = 567), 2 studies used coracoclavicular screws (n = 94), 2 studies used suture fixation (n = 93), 2 studies used suture anchor (n = 55), 2 studies used suture cerclage fixation (n = 87), 1 used single multistrand titanium cable (n = 24), and 1 used K wire (n = 11). The mean follow-up Constant scores ranged from 77.5 to 97.1 in the fixation group compared to 90.3-96.6 in the tendon graft group. The mean visual analog scale scores ranged from 0 to 4.5 in the fixation group and 0.1-1 in the tendon graft group. Net CC distance ranged from 17.5 to 3.6 mm in the fixation group and 7.4-4 mm in the tendon graft group. The revision rates ranged from 0.0% to 18.18% in the direct fixation group and 5.88%-17% in the tendon graft group.

Conclusion

Direct fixation and tendon graft reconstruction for management of acute, high-grade ACJ separations have similar patient subjective and radiographic outcomes, as well as complication and revision rates at a minimum 1-year follow-up.

Bone tunnel placement influences shear stresses at the coracoid process after coracoclavicular ligament reconstruction: a finite element study and radiological analysis

INTRODUCTION

Coracoid fractures after arthroscopic treatment of acromioclavicular (AC) joint separations lead to poor clinical outcomes. In this study, different configurations of bone tunnels in the lateral clavicle and coracoid were examined concerning the amount of stress induced in the coracoid.

METHODS

An authentic 3D finite element model of an ac joint was established. Three 2.4 mm bone tunnels were inserted in the lateral clavicle, which were situated above, medially and laterally of the coracoid. Then, two 2.4 mm bone tunnels were inserted in the latter, each simulating a proximal and a distal suture button position. Von Mises stress analyses were performed to evaluate the amount of stress caused in the coracoid process by the different configurations. Then, a clinical series of radiographs was examined, the placement of the clavicle drill hole was analyzed and the number of dangerous configurations was recorded.

RESULTS

The safest configuration was a proximal tunnel in the coracoid combined with a lateral bone tunnel in the clavicle, leading to an oblique traction at the coracoid. A distal bone tunnel in the coracoid and perpendicular traction as well as a proximal tunnel in the coracoid with medial traction caused the highest stresses. Anatomical placement of the clavicle drill hole does lead to configurations with smaller stresses.

CONCLUSION

The bone tunnel placement with the smallest amount of shear stresses was found when the traction of the suture button was directed slightly lateral, towards the AC joint. Anatomical placement of the clavicle drill hole alone was not sufficient in preventing dangerous configurations.

LEVEL OF EVIDENCE

Controlled laboratory study.

Computed Tomography‐Based Determination of the Optimal Locations of Bone Tunnels for Coracoclavicular Ligament Reconstruction

Objective

An agreement has not been reached on optimal locations of bone tunnels for coracoclavicular ligament (CCL) reconstruction for acromioclavicular joint dislocation (ACD). This study aims to identify the convergence point (cP) between the coracoid process and clavicle in the Chinese population to assist surgeons in reconstructing the CCL for ACD.

Methods

From 2014 to 2020, 483 CT scans of the shoulders of 270 male and 213 female patients (247 right and 236 left shoulders) were collected and studied retrospectively. By overlapping the images of the transverse plane of the coracoid process and the clavicle, points a and b, and the midpoint ab (cP) were determined. Then, a series of parameters through point cP in the transverse and sagittal planes were measured. In the transverse plane this included the distance from point cP to the tip of the coracoid process (cP‐cor),the distance between the medial and lateral margins of the coracoid process through point cP (Med‐lat cor), the distance from point cP to the acromioclavicular joint (cP‐ac), and the distance between the anteroposterior margin of the clavicle through point cP (Ap‐clav). In the sagittal plane, this included the craniocaudal segment of the coracoid process (Cc‐cor), and the craniocaudal segment of the clavicle (Cc‐clav). The sex and side differences of these measurements were also analyzed by two radiologists.

Results

Based on the following measurements, point cP was determined. For male patients, the cP‐cor was 28.02 ± 3.43 mm, Med‐lat cor was 22.78 ± 2.80 mm, Cc‐cor was 15.11 ± 2.13 mm, cP‐ac was 29.24 ± 3.84 mm, Ap‐clav was 18.27 ± 2.46 mm, and Cc‐clav was 10.09 ± 1.56 mm. For female patients, the cP‐cor was 25.20 ± 3.26 mm, Med‐lat cor was 20.21 ± 2.97 mm, Cc‐cor was 13.03 ± 1.77 mm, cP‐ac was 26.66 ± 3.45 mm, Ap‐clav was 16.10 ± 2.30 mm, and Cc‐clav was 8.91 ± 1.40 mm. All the measurements of female patients were lower than those of male patients (p < 0.01). Between sides, only cP‐ac of the left shoulders was significantly lower than those of the right shoulders (p < 0.05), with no significant differences in other parameters between sides (p > 0.05).

Conclusion

The results of this study identified the locations of bone tunnel‐cP in the coracoid process and clavicle for the CCL reconstruction in ACD. Moreover, the findings indicated that surgeons should be more cautious in operating on female patients and that the cP‐ac of left shoulders should be set lower than that of right shoulders.

Arthroscopically assisted single tunnel reconstruction for acute high-grade acromioclavicular joint dislocation with an additional acromioclavicular joint cerclage

PURPOSE

Purpose of this study was to demonstrate that a single tunnel reconstruction of high-grade acromioclavicular (AC) joint instabilities with implants of the second generation is sufficient for stabilisation, especially in combination with an AC cerclage.

METHODS

Patients with an acute AC-joint dislocation type Rockwood III-B and V were included. Besides clinical follow-up examination, radiographs were analysed. The functional outcome measures were Constant Score (CS), Taft score (TS), ACJI score and patient's satisfaction. Horizontal instability was evaluated by clinical examination and radiological with an Alexander view.

RESULTS

Thirty-five patients with a mean follow-up of 29 months were included. Ninety-seven per cent were satisfied with their result, with an average Subjective Shoulder Value of 90%. The CS averaged at 90 ± 10 points, TS at 11 ± 1 points and ACJI at 78 ± 18 points. Radiologically, 3 of 29 patients (10%) showed a persisting horizontal instability. The coracoclavicular (CC) distance improved from 22 preoperative to 10 mm postoperative, which was comparable to the contralateral side (10 mm, p = 0.103). At follow-up the CC distance increased to 13 mm (p = 0.0001).

CONCLUSION

AC-joint stabilisation with a single tunnel reconstruction using a second-generation implant results in good to excellent clinical results with high patient satisfaction. The additional AC augmentation improves stability in horizontal instable AC-joints and is recommended in all high-grade AC joint stabilisations. Nonetheless, reduction was slightly lost over time due to an elongation or suture failure of the coraco-clavicular fixation.

LEVEL OF EVIDENCE

IV.

Sonographic Measurement of Dynamic Horizontal Instability in Acromioclavicular Joint Instability: Description of a Simple Technique and Correlation to Radiographic Parameters

OBJECTIVE

Dynamic horizontal instability is considered to be the main reason for poor outcome after treatment for acromioclavicular (AC) joint instability. In this study, we describe a simple technique to quantify this pathology via sonography.

METHODS

Thirty-six shoulders from 18 patients with ac joint instabilities were examined using modified Alexander views and a standardized sonographic examination. On the Alexander views, overlap of acromion and clavicle (OLAC), glenoid center to posterior clavicle distance (GCPC), and lateral extension (LE) were measured. Afterwards, the results were analyzed and compared with sonography. Posterior translation of the clavicle and the difference of translation between healthy and injured shoulder were evaluated.

RESULTS

The mean age of the patients was 39 ± 14 years (range 19-61 years). We included 4 (22%) Rockwood type 3, 1 (6%) Rockwood type 4, and 13 (72%) Rockwood type 5 lesions. Four (22%) patients were female and 14 (78%) male patients. Posterior clavicle translation of the injured shoulder correlated strongly between OLAC and sonography (r = -0.514, P = .029), and the difference of translation between healthy and injured shoulder correlated very strongly between LE and sonography (r = 0.737, P < .001).

CONCLUSION

The sonographic measurement technique for horizontal instability presented in this work could help detect horizontal instabilities. While the observation of dynamic horizontal displacement is a strength of this technique, measurements are hindered in cases of high coracoclavicular distances.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Clavicular Tunnel Complications after Coracoclavicular Reconstruction in Acute Acromioclavicular Dislocation: Coracoid Loop versus Coracoid Tunnel Fixation

Background

The purpose of this study was to compare clavicular tunnel complications after coracoclavicular (CC) reconstruction between a coracoid loop fixation group and a coracoid tunnel fixation group. We hypothesized that clavicular tunnel complications would be more common in the coracoid loop group.

Methods

This retrospective study evaluated 24 patients who underwent CC reconstruction using coracoid tunnel fixation (n = 14) and coracoid loop fixation (n = 10). Radiographic measurements included the CC distance and clavicular tunnel diameter. Clavicular tunnel complications such as tunnel widening and clavicular tunnel fractures were investigated. Clinical outcomes were assessed using the American Shoulder and Elbow Surgeons Shoulder score and the University of California at Los Angeles Shoulder score.

Results

The mean follow-up period was 17.5 months (range, 11–38 months). The final clavicular tunnel diameter and the increase in the clavicular tunnel diameter in millimeter and percentage were significantly greater in the coracoid loop group than in the coracoid tunnel group (all p < 0.05). Clavicular tunnel widening more than 100% was found in 5 patients, all belonging to the coracoid loop group. Clavicular tunnel fractures occurred in 3 patients (all in the coracoid loop group). Fracture was associated with severe tunnel widening (more than 100% increase). The mean value of the final clavicular tunnel diameter in patients with fractures was significantly larger than that in patients without (12.7 ± 3.3 mm vs. 8.4 ± 1.5 mm, p = 0.016).

Conclusions

Clavicular tunnel complications such as significant tunnel widening and fractures after CC reconstructions in acromioclavicular dislocations were common with the coracoid loop fixation technique. A greater clavicular tunnel widening and resultantly enlarged tunnel diameter might increase the risk of fracture through the clavicular tunnel.

Mid-Term Outcomes of Arthroscopically-Assisted Anatomic Coracoclavicular Ligament Reconstruction Using Tendon Allograft for High-Grade Acromioclavicular Joint Dislocations

PURPOSE

The purposes of this study were to assess clinical and radiographic outcomes of arthroscopically-assisted, anatomic coracoclavicular ligament reconstruction using tendon allograft (AA-ACCR) for the treatment of Rockwood type III-V injuries at minimum 2-year follow-up and to perform subgroup analyses of clinical and radiographic outcomes for acute versus chronic and type III versus type IV-V injuries.

METHODS

In this retrospective study of prospectively collected data, patients who underwent primary AA-ACCR for the treatment of type III-V dislocations and had minimum 2-year follow-up were included. Preoperative and postoperative patient-reported outcome scores (PROs) were collected, including American Shoulder and Elbow Surgeons score, Single Numeric Assessment Evaluation score, Short Form-12 Physical Component Summary, Quick Disabilities of the Arm Shoulder and Hand score, and patient satisfaction. Preoperative and postoperative coracoclavicular distance (CCD) was obtained. PROs and CCD were reported for the total cohort and for the subgroups. Complication and revision rates were demonstrated.

RESULTS

In total, 102 patients (10 women, 92 men) with a mean age of 45.0 years (range, 18-73 years) were included. There were 13 complications (12.7%) resulting in revision surgery. After exclusion of revised patients, PROs were available for 69 (77.5%). At mean follow-up of 4.7 years (range, 2.0-12.8 years), all PROs improved significantly (P < .001). Median patient satisfaction was 9.0 (interquartile range, 8.0-10.0). Median preoperative to postoperative CCD decreased significantly (P < .001). Subgroup analyses revealed significant improvements in all PROs and CCD from preoperative to postoperative for both acute and chronic, and type III and type IV-V dislocations (P < .05) with no significant differences in postoperative PROs and satisfaction between (P > .05).

CONCLUSION

AA-ACCR for high-grade acromioclavicular joint injuries resulted in high postoperative PROs and patient satisfaction with significant improvements from before to after surgery in those who did not undergo revision surgery. Furthermore, subgroup analyses revealed that acute and chronic, and type III and type IV-V injuries benefitted similarly from AA-ACCR.

LEVEL OF EVIDENCE

Level IV; therapeutic case series.

Concomitant Acromioclavicular and Coracoclavicular Ligament Reconstruction with a Duo-Figure-8 Autogenic Graft Wrapping Technique for Treating Chronic Acromioclavicular Separation

Backgroud

Coracoacromial ligament transfer is the traditional procedure for treating chronic acromioclavicular separation, but it is significantly inferior to ligament reconstruction according to biomechanical and clinical studies. However, ligament reconstruction carries the risk of complications of graft loosening and peri-tunnel fractures. Currently, there is no ligament reconstruction procedure optimal for preventing such complications. The purpose of this study was to describe and retrospectively analyze the clinical and radiological outcomes of a “duo-figure-8” autogenic graft wrapping technique, which was used to concomitantly reconstruct the acromioclavicular and coracoclavicular ligaments.

Methods

Preoperative, immediate postoperative, and final follow-up oputcomes were evaluated in 10 enrolled patients. Radiographic outcomes were indicated by the bilateral difference of the coracoclavicular distance (CCD) and overlapping length of the acromioclavicular joint (OLac). Quality of reduction was classified into 4 grades according to bilateral CCD difference into overreduction (< 0 mm), anatomic reduction (0–4 mm), partial loss of reduction (4–8 mm), and recurrent dislocation (> 8 mm). Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) and Constant scores.

Results

The mean side-to-side differences for CCD were 11.9 mm (preoperative), −0.1 mm (immediate postoperative), and 3.4 mm (final follow-up); those for OLac were 9.4 mm (preoperative) and 2.7 mm (final follow-up). CCD and OLac outcomes significantly improved at final follow-up (p < 0.05). At the immediate postoperative stage, 6 and 4 patients had overreduction and anatomic reduction, respectively. At final follow-up, 7 and 3 patients had anatomic reduction and partial loss of reduction, respectively. The magnitude of improvement of ASES scores for patients with anatomic reduction and partial loss of reduction (p = 0.20) was 18.1 and 20.0, respectively. The magnitude of improvement of Constant scores in patients with anatomic reduction and partial loss of reduction (p = 0.25) was 19.9 and 22.3, respectively.

Conclusions

The technique yielded acceptable functional outcomes in patients with anatomic reduction or partial loss of reduction. The “duo-figure-8” wrapping method—a single autogenic tendon graft passing beneath the coracoid process with a tendon-knot fixation over the distal clavicle and looping around the acromion intramedullary—did not increase the risk of peri-tunnel fractures over the clavicle, coracoid process, or acromion.

Anatomic reconstruction of the acromioclavicular joint provides the best functional outcomes in the treatment of chronic instability

PURPOSE

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

METHODS

Studies were identified by electronic databases (Ovid, PubMed). All studies reporting functional and radiological outcomes of surgical treatments of chronic 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

Fourty-four studies were included for a total of 1020 shoulders. Mean age of participants was 38 years. Mean follow-up was 32.9 months. Arthroscopic techniques showed better results than open approach (p < 0.0001). Synthetic reconstructions demonstrated better functional outcomes compared to internal fixation and biologic techniques (p < 0.0001). Among biologic techniques, combined coracoclavicular and acromioclavicular ligaments reconstruction showed better Constant (p = 0.0270) and ASES (p = 0.0113) scores compared to isolated coracoclavicular ligaments reconstruction; anatomic biologic non-augmented graft reconstruction showed better Constant (p < 0.0001), VAS (p < 0.0001) and SSV (p = 0.0177) results compared to augmented techniques. No differences in functional outcomes could be found between anatomic biologic non-augmented graft versus synthetic reconstructions. Overall, methodological quality of the included studies was low.

CONCLUSION

Anatomic reconstructions, both synthetic and biologic, showed the best functional results.

LEVEL OF EVIDENCE

IV.

Clinical Outcome of a Modified Coracoid Tunnel-Free Coracoclavicular Sling Technique With Remnant Preservation for the Treatment of High-Grade Acromioclavicular Joint Separation: A Report of 48 Cases With 2 to 5 Years of Follow-up

BACKGROUND

High-grade acromioclavicular (AC) joint separation injuries (Rockwood type IV or V) are surgically indicated because of complete disruption of the AC and coracoclavicular (CC) ligaments, leading to instability and pain. In surgical techniques that require a suspensory system, coracoid tunnel-related complications are not uncommon.

PURPOSE

To report subjective and objective clinical outcomes and complication rates of a modified coracoid tunnel-free CC sling technique combined with CC ligament remnant preservation for a minimum 2-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between January 2014 and January 2017, we prospectively enrolled patients who underwent a modified CC sling technique performed by 1 senior surgeon using the AC TightRope System in a coracoid tunnel-free fashion. The CC distance (CCD) and Rockwood AC joint classification were evaluated on radiographs preoperatively, immediately postoperatively, and at the final follow-up. The visual analog pain score, range of motion, American Shoulder and Elbow Surgeons score, Constant-Murley score, and University of California Los Angeles score were recorded preoperatively and at the final follow-up.

RESULTS

In total, 48 of 54 patients (88.9%) were included for the evaluation with a mean ± SD follow-up of 39.3 ± 8.9 months (range, 24.7-64.3 months). The CCD was significantly decreased from 22.7 ± 4.2 to 9.8 ± 2.3 mm (P < .01) immediately after surgery and to 11.2 ± 1.8 mm (P < .01) at final follow-up. At the final follow-up, the side-to-side difference of CCD was 3.5 ± 0.6 mm. Compared with the preoperative level, all subjective evaluations were significantly improved at the final follow-up. We observed that 4 of the 48 patients (8.3%) had a loss of reduction at the final follow-up, but no pain or instability was documented. Further, no coracoid-related complication or other complications were recorded.

CONCLUSION

The coracoid tunnel-free CC sling technique using the AC TightRope System combined with CC ligament remnant preservation demonstrated significant improvement regarding both clinical and radiological outcomes, with a reduction loss rate of 8.3%. It is a safe method that could achieve satisfactory result without any coracoid drilling-related complications.

Quantitative and Qualitative Surgical Anatomy of the Acromioclavicular Joint Capsule and Ligament: A Cadaveric Study

BACKGROUND

The acromioclavicular (AC) capsule and ligament have been found to play a major role in maintaining horizontal stability. To reconstruct the AC capsule and ligament, precise knowledge of their anatomy is essential.

PURPOSE/HYPOTHESIS

The purposes of this study were (1) to determine the angle of the posterosuperior ligament in regard to the axis of the clavicle, (2) to determine the width of the attachment (footprint) of the AC capsule and ligament on the acromion and clavicle, (3) to determine the distance to the AC capsule from the cartilage border of the acromion and clavicle, and (4) to develop a clockface model of the insertion of the posterosuperior ligament on the acromion and clavicle. It was hypothesized that consistent angles, attachment areas, distances, and insertion sites would be identified.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 12 fresh-frozen shoulders were used (mean age, 55 years [range, 41-64 years]). All soft tissue was removed, leaving only the AC capsule and ligament intact. After a qualitative inspection, a quantitative assessment was performed. The AC joint was fixed in an anatomic position, and the attachment angle of the posterosuperior ligament was measured using a digital protractor. The capsule and ligament were removed, and a coordinate measuring device was utilized to assess the width of the AC capsule footprint and the distance from the footprint to the cartilage border of the acromion and clavicle. The AC joint was then disarticulated, and the previously marked posterosuperior ligament insertion was transferred into a clockface model. The mean values across the 12 specimens were demonstrated with 95% CIs.

RESULTS

The mean attachment angle of the posterosuperior ligament was 51.4° (95% CI, 45.2°-57.6°) in relation to the long axis of the entire clavicle and 41.5° (95% CI, 33.8°-49.1°) in relation to the long axis of the distal third of the clavicle. The mean clavicular footprint width of the AC capsule was 6.4 mm (95% CI, 5.8-6.9 mm) at the superior clavicle and 4.4 mm (95% CI, 3.9-4.8 mm) at the inferior clavicle. The mean acromial footprint width of the AC capsule was 4.6 mm (95% CI, 4.2-4.9 mm) at the superior side and 4.0 mm (95% CI, 3.6-4.4 mm) at the inferior side. The mean distance from the lateral clavicular attachment of the AC capsule to the clavicular cartilage border was 4.3 mm (95% CI, 4.0-4.6 mm), and the mean distance from the medial acromial attachment of the AC capsule to the acromial cartilage border was 3.1 mm (95% CI, 2.9-3.4 mm). On the clockface model of the right shoulder, the clavicular attachment of the posterosuperior ligament ranged from the 9:05 (range, 8:00-9:30) to 11:20 (range, 10:00-12:30) position, and the acromial attachment ranged from the 12:20 (range, 11:00-1:30) to 2:10 (range, 13:30-14:40) position.

CONCLUSION

The finding that the posterosuperior ligament did not course perpendicular to the AC joint but rather was oriented obliquely to the long axis of the clavicle, in combination with the newly developed clockface model, may help surgeons to optimally reconstruct this ligament.

CLINICAL RELEVANCE

Our results of a narrow inferior footprint and a short distance from the inferior AC capsule to cartilage suggest that proposed reconstruction of the AC joint capsule should focus primarily on its superior portion.

RR, Costa G, Verdalet I, Ezzeddine H, Rius X. Arthroscopically Assisted Comprehensive Double Cerclage Suture Fixation Technique for Acute Acromioclavicular Joint Separation

Acromioclavicular dislocations are some of the most frequently recorded and controversial injuries in the athletic population. These injuries have historically been a matter of disagreement between surgeons, particularly when it comes to the surgical technique used to treat them, its approach, or its timing. Consensus over the "gold standard" procedure to treat them is yet to be established. Even though numerous surgical techniques have already been described, the number of complications and loss of reduction remains a matter of concern for treating physicians. Here, we present an arthroscopically assisted coracoclavicular and horizontal acromioclavicular fixation technique in a modified figure-of-eight configuration using 2 strong FiberTape Cerclage sutures, with measurable tension, for the comprehensive treatment of acromioclavicular joint dislocations.

Novel Double Endobutton Technique Combined with Three-Dimensional Printing: A Biomechanical Study of Reconstruction in Acromioclavicular Joint Dislocation

Objective

To reconstruct the acromioclavicular (AC) joint using an adjusted closed‐loop double Endobutton technique via a guiding locator that was applied using three‐dimensional (3D) printing technology. At the same time, the reliability and safety of the novel double Endobutton (NDE) were tested by comparing the biomechanics of this technique with the TightRope (TR) approach.

Methods

This retrospective study was conducted between January 2017 and January 2019. The Department of Anatomy at Southern Medical University obtained 18 fresh‐frozen specimens (8 left and 10 right; 12 men and 6 women). First, the guiding locators were applied using 3D printing technology. After preparation of materials, specimens were divided into an NDE group, a TR group, and a normal group. In the NDE and TR groups, the navigation module was used to locate and establish the bone tunnels; after that, the NDE or TR was implanted. However, the Endobuttons were fixed while pressing the distal clavicle downwards and the length of the loop could be adjusted by changing the upper Endobutton in the NDE group while the suture button construct was tensioned and knotted after pressing down the distal clavicle in the TR. Finally, load testing in anterior–posterior (AP), superior–inferior (SI), and medial–lateral (ML) directions as well as load‐to‐failure testing in the SI direction were undertaken to verify whether the NDE or TR had better biomechanics.

Results

In the load testing, the displacements of the NDE and TR groups in the AP, SI, and ML direction were significantly shorter than those of the normal group (P < 0.05). In the load‐to‐failure testing, the ultimate load of the NDE and TR groups had significantly higher increases than the normal group (722.16 ± 92.04 vs 564.63 ± 63.05, P < 0.05; 680.20 ± 110.29 vs 564.63 ± 63.05, P < 0.05). However, there was no statistically significant difference between the two techniques for these two tests (P > 0.05). In the NDE group, four of six failures were a result of tunnel fractures of the coracoid, while two of six were due to suture breakage. In the TR, three failures were due to coracoid tunnel fractures, one was a result of a clavicle tunnel fracture, and the rest were due to suture breakage. In the normal group, half of the failures were a result of avulsion fractures of the conical ligament at the point of the coracoid process, and the other three were due to rupture of the conical ligament, fracture of the distal clavicle, and fracture of the scapular body.

Conclusion

As for the TR technique, the stability and strength of the AC joint were better in patients who underwent reconstruction using the NDE technique than in the intact state.

A biomechanical comparison of different tying techniques of a double-stranded looped suture

PURPOSE

This study aims to assess the biomechanical performance of different tying techniques of a double-stranded looped suture (DSLS).

METHODS

Loop and knot security of DSLS tying techniques (nice knot (NK), modified nice knot (MNK), double-twist knot (DTK), and double-barrel knot (DBK)) were compared. The square knot of DSLS (SKD) and the square knot of single-stranded suture (SKS) had been used as references. Twenty-four loops of each configuration were created using No. 2 Fiberwire (Arthrex, Naples, Florida, USA) and tested with a material testing machine. Samples were loaded with 10 N preloads for loop security assessment. Knot security was subsequently evaluated. Twelve loops of each knot were loaded to failure. The rest were subjected to cyclic load testing and the elongation at the 50th and 1000th cycles were measured. Knot bulkiness was determined by measuring knot height before testing. Data were compared with analysis of variance and post hoc tests. Statistical significance was p < 0.05.

RESULTS

All knots showed no statistically significant difference in displacement with preload. The load-to-failure was highest in NK, followed by MNK, DTK, DBK, SKD, and SKS. The cyclic loading test at the 50th cycle and the 1000th cycle demonstrated that NK has significantly less displacement than the others except MNK. DTK provided a minimal average knot height followed by NK, SKS, DBK, MNK, and SKD.

CONCLUSION

The different tying techniques in DSLS provided the similar loop security but different knot security and knot bulkiness. NK and MNK are biomechanically superior to the other knots, whereas DTK is the least bulky. The findings in the present study may help set the guide for the surgeons to select the tying technique of DSLS to best suit their requirement.

Radiographic features and complications following coracoclavicular ligament reconstruction

OBJECTIVE

To report radiographic features and complications of coracoclavicular ligament reconstruction and the association of radiographic features with symptomatology.

MATERIALS AND METHODS

Retrospective picture archiving and communication system query (1/2012-8/2018) identified subjects with prior coracoclavicular ligament reconstruction. Post-operative radiographs were reviewed with attention to the following: (1) acromioclavicular alignment, (2) coracoclavicular width, (3) distal clavicular osteolysis, (4) osseous tunnel widening, and (5) hardware complication or fracture. Medical records were reviewed to determine purpose of imaging follow-up (symptomatic versus routine). Statistical analysis determined associations between binary features and outcomes, and inter-reader agreement.

RESULT

Review of 55 charts identified 32 subjects (23 male, 9 females; age range 24-64; imaged 1-34 months following surgery) meeting inclusion criteria. Loss of acromioclavicular reduction was the most common imaging finding (n = 25, 78%), with 76% progressing to coracoclavicular interval widening. Distal clavicular osteolysis was seen in 21 cases (66%) and was significantly associated with loss of acromioclavicular joint reduction (p = 0.032). Tunnel widening occurred in 23 patients (82%) with more than one follow-up radiograph. Six (19%) had hardware complication or fracture. No radiographic feature or complication had significant correlation with symptomatology (p values 0.071-0.721). Inter-reader agreement was moderate to substantial for coracoclavicular interval widening and hardware complication, fair to substantial for tunnel widening, and fair to moderate for loss of acromioclavicular reduction and distal clavicular osteolysis.

CONCLUSION

Loss of acromioclavicular joint reduction, coracoclavicular interval widening, distal clavicular osteolysis, and tunnel widening are common radiographic features after coracoclavicular ligament reconstruction; however, they do not necessarily correlate with symptomatology.

High grade acromioclavicular injury: Comparison of arthroscopic assisted acromioclavicular joint fixation and anatomic acromioclavicular joint reconstruction

Background

Injuries to the acromioclavicular (AC) joint disrupting the AC and Coracoclavicular (CC) ligaments could lead to loss of clavicular strut function. A High-grade AC joint injury remain challenging because of highly variety of treatment and limited evidence exists comparing clinical outcomes and complications after surgery.

Purpose

The purpose of this study was to compare the clinical and radiological outcome after arthroscopic assisted acromioclavicular Joint fixation and anatomic acromioclavicular joint reconstruction.

Study design

Retrospective Clinical Cohort Study.

Methods

Twenty-nine patients with a high grade (Rockwood Type III-V) Acromioclavicular Joint Injury, operatively treated with arthroscopic assisted acromioclavicular joint fixation and anatomic acromioclavicular joint reconstruction from 2012 to 2018. The clinical assessment consists of Specific AC Score (SACS) and Nottingham Score. The radiographic evaluations were performed to evaluate the stability of reduction and the complications are assessed.

Results

There were a significant different between groups with AC joint reconstruction and fixation group (20 vs. 8, p < 0.005) and (19 vs. 10, p < 0.005) in SAC score and Nottingham score, respectively. There were no significant different in CC dstance between two groups. At the last follow up 6 patient develop loss of reduction with CC percentage >50% in AC joint fixation. Complication developed in 5 patients (17%) including 2 mild osteolysis, 1 superficial infection, 1 implant failure, and 1 clavicle fracture.

Conclusion

Anatomic AC joint reconstruction was associated with functional and radiologic benefits and better restored the stability.

Coracoid clavicular tunnel angle is related with loss of reduction in a single-tunnel coracoclavicular fixation using a dog bone button in acute acromioclavicular joint dislocation

PURPOSE

Despite the high failure rates of techniques used to maintain the reduction of single-tunnel coracoclavicular (CC) fixation, analyses of the etiology of loss of reduction related to surgical techniques are limited. Therefore, it was hypothesized that the initial coracoclavicular tunnel angle was related to loss of reduction in the single-tunnel technique for AC joint dislocation. This study aimed to evaluate the clinical and radiological outcomes of arthroscopic single-tunnel CC suture button fixation according to the initial coracoclavicular tunnel angle.

METHODS

Thirty-two consecutive patients who underwent arthroscopic single-tunnel CC suture button fixation for AC joint dislocation from 2014 to 2018 were enrolled. The tunneling-first technique was used in the first 11 patients, while the reduction-first technique was used in the remaining 22 consecutive patients. For clinical assessments, the American Shoulder and Elbow Surgeons (ASES) score and Korean Shoulder Score (KSS) were recorded. For radiological evaluation, coracoclavicular distance ratio, coracoclavicular tunnel angle, coracoid, and clavicular tunnel widths were measured.

RESULTS

The ASES score did not differ significantly between the two groups (n.s.). However, the KSS was significantly better in the reduction-first group (p = 0.031). No significant intergroup differences were observed in the pre- and postoperative coracoclavicular distance ratio. However, at the last follow-up, loss of coracoclavicular distance ratio was significantly smaller in the reduction-first group (p < 0.001). At the final follow-up, loss of the coracoclavicular distance ratio was positively correlated with the postoperative coracoclavicular tunnel angle (p < 0.001, Spearman's rho correlation coefficient = 0.602). The final follow-up clavicular tunnel width was also significantly smaller in the reduction-first group (p = 0.002). Finally, the last follow-up clavicular tunnel width was positively correlated with the postoperative coracoclavicular tunnel angle (p = 0.008, Spearman's rho correlation coefficient = 0.459).

CONCLUSION

The reduction-first technique showed better clinical and radiological outcomes than the tunneling-first technique in single-tunnel CC fixation for AC joint dislocation. A large postoperative coracoclavicular tunnel angle was associated with loss of reduction and clavicular tunnel widening. Therefore, obtaining a straight coracoclavicular tunnel angle is crucial for achieving better outcomes and minimizing loss of reduction.

LEVEL OF EVIDENCE

III.

An Arthroscopic Modification of Coracoclavicular Ligament Reconstruction and Distal Clavicle Fracture Fixation in the Lateral Position

Distal clavicle fractures and acromioclavicular injuries are common shoulder injuries. Despite the frequency of these injuries, there is no gold standard for treatment. Recent suspensory fixation techniques have minimized the amount of hardware required for surgical treatment of both acromioclavicular separations and distal clavicle fractures. Advantages include reconstruction of ligamentous anatomy, minimal hardware irritation, earlier return to activity, and decreased need for hardware removal. These reconstructions are classically done in the beach chair position in an open fashion. Our preferred technique for treatment of unstable distal clavicle fractures and acromioclavicular injuries is arthroscopy-assisted coracoclavicular ligament reconstruction with or without distal clavicle fixation in the lateral decubitus position.