AC Joint Reconstruction
AC Joint Reconstruction – Modified Weaver Dunn
The acromioclavicular joint (AC joint) is one of the 3 joints in the shoulder and connects the clavicle (collar bone) to the scapula (shoulder blade). The AC joint is held with 4 main ligaments, the superior (above the joint) and inferior (below the joint) ligaments, the coracoclavicular ligaments, and the coracoacromial ligament.
Coracoclavicular ligaments are the ligaments that connect the coracoids process (bony prominence on the scapula) and the clavicle. Coracoacromial ligament connects the acromion to the coracoid process. Injury to AC joint causes separation and the tear of ligaments. More severe cases require AC joint reconstruction surgery to stabilize the joint which involves replacement of torn ligaments and stabilizing the reconstruction.
Modified Weaver-Dunn Technique
The original Weaver-Dunn procedure involves removal of a portion of clavicle bone at its lateral end, separation of coracoacromial ligament from acromion, preparation of coracoacromial ligament and reattachment of the ligament to clavicle bone. The modified Weaver-Dunn technique involves additional stabilization of the transferred ligament using screws or suture around the coracoids & clavicle.
During the procedure, surgeon expose AC joint by an incision from top-front of the shoulder extending down over the coracoids process. The lateral end of the clavicle is cut in oblique angle and the coracoacromial ligament is detached along with a piece of bone from acromion. Surgeon drills holes in clavicle bone to fix the detached coracoacromial ligament and drills the inner core of clavicle. Then the new ligament is pulled in to the cavity and is secured using the suture cords. Furthermore, a suture cord is passed around the base of coracoids and clavicle to stabilize the reconstruction. Following reconstruction and stabilization the surrounding muscles are repaired and incisions are closed.
Postoperative rehabilitation includes use of shoulder sling for 6 weeks followed by physical therapy exercises. This helps restore movements and improve strength. All movements and activities above the shoulder level must be avoided for first 12 weeks following surgery.
The most common complications of surgery include infection, nerve and blood vessel injuries, continued pain or stiffness, fracture, unsuccessful surgery, ligaments re-tear, and revision surgery.