Chronic AC joint separation - Reconstruction using allograft and anatomic technique

Chronic AC joint separations are a challenging problem which requires non biologic and biologic fixation to avoid failure of the reconstructive surgery. Surgical treatment is offered to candidates who can be compliant with the restrictions in activity. Healing requires at least 3 months as tendon to bone healing is involved with this type of reconstruction. From the ACL reconstruction literature it is known that tendon to bone healing is completed at 6 months based on histology. For that reason, return to full activity is permitted at 6 months.

The biologic reconstruction is achieved by looping a tendon allograft (semitendinosus, or gracilis) around the base of the coracoid and fixing it through drill holes in the lateral clavicle. We avoid drilling of the coracoid because it creates a stress riser that may lead to coracoid fracture. The Augustus Mazzocca technique provides an anatomic fixation which mimics the anatomy of trapezoid an conoid ligaments. This technique is depicted below.

The non biologic reconstruction is achieved by looping a No 2 Fiberwire around the coracoid. This type of fixation may eventually fail but in the meantime the incorporation of the tendon graft in the bone tunnels will be complete and strong fixation may be achieved. There is a concern for fracture through the drill holes of the clavicle but it seems to be of low risk because the drill holes are filled with biotenodesis screws. Below are the images of such a reconstruction.

 Axillary view showing the posterior dislocation of the clavicle

AP view showing more than 100% displacement of the clavicle superiorly

 Restoration of the position of the clavicle relative to the acromion using the tendon allograft that was looped around the base of the coracoid (red line). The screws and tunnels are visible.