Actualities in acromioclavicular injuries

Abstract

Acromioclavicular (AC) joint injuries most commonly occur in young adults involved in sports and overhead activities. They account for 3% of all shoulder injuries and 40% of shoulder sports injuries. The person who sustains an AC injury commonly reports direct or indirect mechanisms of injury. Direct force is when the person falls on to the point of the shoulder, with the arm usually at the side and adducted. The force drives the acromion downwards and medially. Indirect force is when the person falls onto an outstretched arm. The force is transmitted through the humeral head to the acromion, therefore the acromioclavicular ligament is disrupted and the coracoclavicular ligament is stretched. Is very importante to identify the injury type, because the treatment and prognosis hinge on an accurate diagnosis? The AC injuries are classified as grades I, II and III, representing respectively, no involvement, partial tearing, and complete disruption of the coracoclavicular ligaments. More recently, Rockwood has further classified the more severe injuries as grades I-VI. The treatment of AC joint injuries varies according to the severity or grade of the injury. Ice packs, anti-inflammatories and a sling are used to immobilise the shoulder and take the weight of the arm. As pain starts to subside, it is important to begin moving the fingers, wrist and elbow, than shoulder to prevent stiffness. Undisplaced injuries only require rest, ice, and then gradual return to activity over a 2-6 week period. Surgical repair can be divided into: acromioclavicular repairs; coracoclavicular repairs; distal clavicular excision and dynamic muscle transfers. Disadvantages of surgery are that there are risks of infection, a longer time to return to full function and continued pain in some cases. For the patient with a chronic AC joint dislocation or subluxation that remains painful after 3 to 6 months of closed treatment and rehabilitation, surgery is indicated to improve function and comfort. For sequelae of untreated type IV-VI, or painful type II and III injuries, the Weaver Dunn technique is advocated. Postoperatively, the arm is supported in a sling for up to 6 weeks. After the first 2 weeks, the patient is allowed to use the arm for daily activities at waist level. After 6 weeks, the sling or orthosis is discontinued, overhead activities are allowed. AC joint injuries are an important source of pain in the shoulder region and must be evaluated carefully. Type I and II injuries are treated symptomatically. The current trend in uncomplicated type III injuries is a non-operative approach. If it develops subsequent problems, a delayed reconstruction may be undertaken. Type IV- VI injuries are generally treated operatively.