Arthrosis of the Acromioclavicular joint and distal clavicular osteolysis
What is arthrosis of the Acromioclavicular joint?
The acromioclavicular joint (CAA) is the articulation between the acromial process of the scapula (shoulder blade) and the lateral end of the clavicle. It is one of the important functional joints of the shoulder, allowing full mobilities of the glenohumeral joint. The joint capsule and numerous ligaments maintain the articulation stable, assisted by the trapezius and the coracoclavicular ligaments that connect the coracoid process of the scapula to the middle / lateral third of the clavicle.
CAA arthrosis can occur after injury or overuse (sports practice, weightlifting) or more rarely as a primary occurrence with no apparent cause. Distal clavicular osteolysis may occur spontaneously in rheumatoid arthritis, hyperparathyroidism, myeloma, systemic sclerosis, infection, and joint overuse.
What are the associated symptoms?
It presents as lateral shoulder pain and/or pain localized to the CCA, which may be swollen, usually worsening at night and with passive and active mobilizations. It can simply be located to the deltoid muscle.
At clinical examination, the pain worsens at the crossing/adduction arm test and may be associated with decreased mobility in prolonged arthrosis.
What is the treatment?
It consists on activity modification, physiotherapy and anti-inflammatory or analgesic drugs. Intraticular corticosteroid injections can provide relief of symptoms. In the presence of severe arthrosis or osteolysis that do not respond to conservative treatment, the resection of the distal clavicle may be indicated and may be performed arthroscopically, without major consequences in shoulder functions, that will maintain mobility and strength, thanks to the stabilization of the clavicle by ligaments that remain intact after surgery.