Distal clavicle degenerative joint disease---or acromioclavicular, or AC, joint arthritis---refers to the process of arthritic changes to the junction of the clavicle and acromion process of the scapula bone in the shoulder. The AC joint contains a fibrocartilagenous disk that can degenerate with age. The changes associated with arthritis include joint space narrowing, thickening or sclerosis of the bone, cysts, and bone spurs or osteophytes. Osteophytes typically form at the distal clavicle.
Symptoms
Symptoms vary among patients. Most patients describe pain with overhead activities. Patients have some mild swelling over the AC joint. Pain is typically worsened by activity, according to the "AAOS Comprehensive Orthopaedic Review."
Physical Exam Findings
Physicians are usually able to elicit tenderness when there is pressure applied to the AC joint. There may be a small degree of noticeable swelling over the affected joint. The joint may be more painful when the physician passively moves the arm across the body, known as a horizontal cross-body adduction test, according to the "AAOS Comprehensive Orthopaedic Review." A spasm may be present in the trapezius muscle, according to the Wheeless' Textbook of Orthopaedics website.
Imaging
Physicians will typically order imaging studies to further evaluate the joint. Plain X-rays are typically ordered to evaluate the general bony anatomy. Signs of osteoarthritis can usually be observed on plain X-rays. MRI is occasionally used to evaluate the soft tissue structures of the shoulder and evaluate the joint for swelling. Findings on imaging do not always correlate well with symptoms that a patient may be experiencing.
Non-Operative Management
The basics of non-operative management for arthritis include rest, ice, nonsteroidal anti-inflammatory medications and activity modification. Some patients benefit from physical therapy. Corticosteroid injections may be helpful to decrease the swelling in the joint and improve pain.
Surgical Treatments
Surgery can be indicated if patients fail to improve on non-operative therapies. Common surgical procedures include arthroscopic or open distal clavicle resection. These procedures involve removing part of the distal clavicle, according to "AAOS Comprehensive Orthopaedic Review." A subacromial decompression surgery that involves removing the underside of the acromion to increase the space where the rotator cuff passes under the acromion can also be performed.
References
- "AAOS Comprehensive Orthopaedic Review"; Dr. Jay Lieberman; 2008
- Wheeless' Textbook of Orthopaedics: AC Joint Arthrosis/Distal Clavicle Excision
