Summary

We achieved good results by indirectly reducing fractures of the distal clavicle with conoid ligament damage using the minimally invasive surgical technique of arthroscopic conoid ligament reconstruction. Anatomical reconstruction of the conoid ligament might stabilize not only the superior displacement of the displaced proximal fragment of the clavicle but also its posterior displacement.

Abstract

Background

The distal clavicle fractures are divided into three types according to Neer’s classification. Type 1 and 3 fractures are treated with a sling to immobilize the upper extremity. However, the treatment of type 2 fractures is controversial. We paid attention to the anatomic basis of type 2 fractures that the disruptions of the conoid ligament lead to the distraction between the two bony fragments. In this study, we described the arthroscopic procedure to reconstruct the disrupted ligament and stabilize the fracture as a minimally invasive method. Also, we evaluated whether this reconstruction of the conoid ligament is useful to reduce the posterior displaced fragment of the proximal clavicle or not.

Materials And Methods

The subjects were 14 patients with the distal clavicle fractures (13 males and one female). The mean age at the time of the surgery was 41.9 years old. The right side was affected in 8 patients, and the left side in 6 patients. The mean time of the surgery from the injury was 3.5 days. Our surgical procedure was performed with the patient in the beach chair position. We have used the artificial ligament with an EndoButton as the substitute ligament to reconstruct the disrupted conoid ligament. The mean duration of postoperative follow-up was 2 years and 7 months.

Results

The bony union was achieved in all patients at final follow-up. At after surgery or final follow-up, we confirmed that the posterior displaced proximal clavicle was reduced on both radiographic findings and 3D computed tomography. Concerning the range of motion at final examinations, mean forward flexion was 171 degrees, mean abduction was165 degrees, and mean horizontal adduction was 132 degrees. There was no intra-operative complication, such as fixation failure or coracoids fracture.

Discussion

There are doubts as to whether arthroscopic conoid ligament reconstruction can stabilize the translation of the posteriorly displaced proximal fragment of the clavicle. No study has investigated the role of the conoid ligament in fractures of the distal clavicle. Although many researchers agree that the conoid ligament functions to restrict the superior translation of the clavicle, whether it has any other function in stabilizing translation is unclear. Because the anatomical course of the conoid ligament runs from the base of the coracoid process to the conoid tubercle, reconstructing it so that it follows its original course might reduce or stabilize the displacement of the posterior margin of the clavicle to a line extending from the posterior margin of the base of the coracoid process in the sagittal plane. Therefore, anatomical reconstruction of the conoid ligament might stabilize not only the superior displacement of the displaced proximal fragment of the clavicle but also its posterior displacement. In fact, postoperative plain radiography and 3DCT revealed good reduction of the posterosuperiorly displaced proximal fragment of the clavicle in all cases.

Conclusions

It is possible to treat the distal clavicle fractures by a minimally invasive arthroscopic procedure. Also, we confirmed that the reconstructed conoid ligament was useful to reduce the posterior dislocated clavicle.