Anatomic Tunnel Placement Is Not Feasible by Transclavicular-Transcoracoid Drilling Technique for Coracoclavicular Reconstruction: A Cadaveric Study

Transcoracoid Drilling for Coracoclavicular Ligament Reconstructions in Patients With Acromioclavicular Joint Dislocations Result in Eccentric Tunnels

Purpose

To determine the location of coracoid inferior tunnel exit with superior-based tunnel drilling and coracoid superior tunnel exit with inferior-based tunnel drilling.

Methods

Fifty-two cadaveric embalmed shoulders (mean age 79 years, range 58-96 years) were used. A transcoracoid tunnel was drilled at the center of the base. Twenty-six shoulders were used for the superior-to-inferior tunnel drilling approach and 26 shoulders for the inferior-to-superior tunnel drilling approach. The distances to the margins of the coracoid process, from both the entry and exit points of the tunnel, were measured. Paired Student t-tests were used to compare the distance from the center of the tunnel and the medial and lateral coracoid border and the apex.

Results

The mean difference for the distances between superior entry and inferior exit from the apex was 3.65 ± 3.51 mm (P = .002); 1.57 ± 2.27 mm for the lateral border (P = .40) and 5.53 ± 3.45 mm for the medial border (P = .001). The mean difference for the distances between inferior entry and superior exit from the apex was 16.95 ± 3.11 mm (P = .0001); 6.51 ± 3.2 mm for the lateral border (P = .40) and 1.03 ± 2.32 mm for the medial border (P = .045). Inferior-to-superior drilling resulted in 4 (15%) cortical breaks.

Conclusions

Both superior-to-inferior and inferior-to-superior tunnel drilling directed the tunnel from a more anterior and medial entry to a posterior-lateral exit. Superior-to-inferior drilling resulted in a more posteriorly angled tunnel. When using a 5-mm reamer and inferior-to-superior tunnel drilling, cortical breaks were observed at the inferior and medial margin of the tunnel exit.

Clinical Relevance

Arthroscopic-assisted acromioclavicular joint reconstruction using conventional jigs may result in an eccentric coracoid tunnel, possibly introducing stress risers and fractures. To avoid cortical breaks and eccentric tunnel placement, open drilling from superior-to-inferior with a superiorly centered guide pin and arthroscopic visualization of a centered inferior exit should be considered.

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.

Anatomy and Correlation of the Coracoid Process and Coracoclavicular Ligament Based on Three-Dimensional Computed Tomography Reconstruction and Magnetic Resonance Imaging

Background

The anatomy of the coracoid process and coracoclavicular (CC) ligament have been described and the correlation between them has been assessed based on 3-dimensional computed tomography (CT) reconstruction and magnetic resonance imaging (MRI), which provide a guide for coracoclavicular ligament reconstruction.

Material/Methods

Data were collected from 300 patients who underwent both CT and MRI of the shoulder joint from January 2017 to January 2019 at the Jiang’an Hospital of Traditional Chinese Medicine. The coracoid process was observed and classified and parameters of the CC ligament were measured according to different corneal types. All of the statistics were collected and classified by 2 radiologists, and average values were determined.

Measurements of segments were taken as follows: ab – In the coronal plane, the length of the CC ligament from the central point of the CC ligament at the clavicular attachment to the CC ligament at the center of the CC attachment); ac – The distance from the center point of the CC ligament at the supraclavicular attachment to the acromioclavicular joint; de – In the sagittal plane, the length of the CC ligament from the center of the clavicular attachment to the coracoid attachment point; fg – The maximum diameter of the CC ligament at the anterior and posterior margins of the clavicle attachment; hi – The largest diameter of the CC ligament at the anterior and posterior edge of the coracoid process attachment; dj – The distance of the coracoclavicular ligament from the center point of the coracoid process attachment to the coracoid process tip; kl – The distance in the supraclavicular plane from the coracoclavicular ligament to the subcoracoid process.

Results

The analysis showed that there are 5 types of coracoid process: gourd (31%), short rod (20%), long rod (22.3%), wedge (10.3%), and water drop (6.3%). There were statistically significant differences between the lengths of the ac and hi segments in the among the wedge and gourd-type and the short rod and water drop-type coracoid processes. There were statistically significant differences between the lengths of the ab, de, and fg segments in the short rod, gourd, and long rod-type coracoid processes. There were statistically significant differences between the lengths of the ac, fg, hi, dj, and kl segments in the water drop, gourd, and long rod-type coracoid processes.

Conclusions

The present study indicated that measurement of the CC ligament and the different shapes of the coracoid process provide an anatomical basis for the diagnosis and treatment of shoulder diseases and the data can be used to improve the safety of CC ligament reconstruction.

Superior clavicle drilling points and fluoroscopic inclination for anatomic coracoclavicular ligament reconstruction: a cadaveric study

PURPOSE

This study aims to investigate the superior clavicle cortex drilling points and fluoroscopic inclination angles for anatomic tunnel drilling in coracoclavicular ligament reconstruction.

METHODS

Twelve cadaveric shoulders with a mean age of 55.9 ± 6.2 years were investigated. Two 2.0 mm Kirschner wires were inserted penetrating the footprint centers of conoid and trapezoid both on the clavicle and coracoid. The location of the Kirschner wires on the superior clavicle cortex was measured. Fluoroscopy was used to obtain three views of shoulder: an anteroposterior, lateral, and cortical ring sign view. Reproducible angles were then recorded.

RESULTS

The Kirschner wire penetrating the conoid was located 40.0 ± 3.9 mm from the distal end and 18.1 ± 3.0 mm from the anterior edge of the clavicle. For the trapezoid, the Kirschner wire was located 19.1 ± 3.6 mm from the distal end and 9.9 ± 3.9 mm from the anterior edge. On the anteroposterior view, the conoid was 11.1° ± 10.1° medially and trapezoid was 26.8° ± 11.8° laterally tilted to the glenohumeral joint line. On the lateral view, the conoid was 42.8° ± 15.1° and trapezoid was 15.5° ± 12.0° superiorly tilted to the scapular spine. On the cortical ring sign view, the conoid was 50.8° ± 12.9° and trapezoid was 14.2 °± 11.0° superiorly tilted to the scapular spine.

CONCLUSIONS

The superior clavicle cortex drilling points and fluoroscopic inclination angles for anatomic tunnel drilling in coracoclavicular ligament reconstruction were demonstrated. Arthroscopy-assisted anatomic coracoclavicular ligament reconstruction has increased in popularity, and these findings may facilitate a more anatomic approach to coracoclavicular ligament reconstruction.

Intraoperative and Postoperative Complications after Arthroscopic Coracoclavicular Stabilization

Background

Arthroscopic stabilization of torn coracoclavicular (CC) ligaments gained popularity recently. However, loss of reduction after the operation and complications unique to this technique involving tunnel placement through the distal clavicle and coracoid process are concerns. The purpose of this study was to report intraoperative and early postoperative complications associated with this procedure.

Methods

This study retrospectively evaluated 18 consecutive patients who had undergone arthroscopic stabilization for torn CC ligaments between 2014 and 2015. The indications for surgery were acute or chronic acromioclavicular dislocation and acute fracture of the distal clavicle, associated with CC ligament disruption. Clinical outcomes were evaluated with the American Shoulder and Elbow Surgeons (ASES) and the University of California, Los Angeles (UCLA) scores. Intra- and postoperative complications and reoperations were investigated.

Results

There were six female and 12 male patients with a mean age of 47 years (range, 22 to 86 years). At a mean follow-up of 17 ± 10 months (range, 10 to 28 months), the mean ASES score was 88.8 ± 19.9 and the mean UCLA score was 30.9 ± 5.2. Intraoperatively, seven complications developed: breach of lateral cortex of the coracoid process in five patients, medial cortex of the coracoid process in one, and anterior cortex of the clavicle in one. Postoperative complications developed in eight patients: four ossifications of the CC interspace, four tunnel widening of the clavicle, one bony erosion on the clavicle, and one superficial infection. A loss of reduction was found in six patients. Reoperation was performed in three patients for loss of reduction in two and superficial infection in the other.

Conclusions

Arthroscopic CC stabilization resulted in high rates of intraoperative and early postoperative complications. Most of them were related to the surgical technique involving bone tunnel placement in the coracoid process and the clavicle.

Editorial Commentary: Drilling Is Never Easy Nor Without Danger in the Shoulder Region

Drilling anatomic tunnels when performing coracoclavicular reconstruction might jeopardize the medial cortex of the coracoid process.