From the Guidelines
Physical examination findings for an acromioclavicular (AC) joint separation typically include visible deformity with a step-off or prominence of the distal clavicle, especially in higher-grade injuries. The diagnosis of AC joint separation is primarily based on clinical examination and radiography, as stated in the study by 1. Key findings include:
- Visible deformity with a step-off or prominence of the distal clavicle
- Point tenderness directly over the AC joint
- Pain exacerbated with horizontal adduction of the arm across the chest (cross-body adduction test) and with active shoulder movement, particularly abduction above 90 degrees
- A visible gap between the acromion and clavicle in more severe separations
- The piano key sign, where the displaced clavicle can be pushed down but springs back up when pressure is released
- Patients often hold the affected arm close to the body and support it with the opposite hand
- Swelling and bruising around the joint are common
- Limited range of motion due to pain These findings vary based on the grade of separation, with higher grades showing more obvious deformity and instability, as noted in the context of traumatic shoulder pain by 1. It is essential to assess neurovascular status of the extremity to rule out associated injuries, considering the potential for underreported cases of low-grade acromioclavicular separations and acute rotator cuff tears, as mentioned in the study by 1.
From the Research
Physical Exam Findings for AC Joint Separation
The physical exam findings for AC joint separation are not explicitly described in the provided studies. However, the studies discuss the diagnosis and management of AC joint separations, which can be inferred to involve physical exam findings.
- The studies mention that AC joint separations are graded according to severity from grade I to grade VI, with grade I being a mild sprain and grade VI being a severe dislocation with displacement 2, 3.
- The mechanism of injury, typically a direct force against the lateral aspect of the adducted shoulder, can affect the severity of the injury and the resulting physical exam findings 3.
- Physical exam findings may include pain, swelling, and tenderness over the AC joint, as well as limited mobility and strength in the shoulder 4.
- Ultrasound-guided injection of an anesthetic agent into the AC joint has been shown to be effective in managing pain in patients with AC joint separation, which may be used in conjunction with physical exam findings to diagnose and manage the condition 4.
Diagnostic Imaging and Treatment
The studies also discuss the use of diagnostic imaging, such as ultrasound, to evaluate AC joint separations and guide treatment.
- Ultrasound can be used to locate the AC joint and guide injections of anesthetic agents or other treatments 4.
- Other imaging modalities, such as X-rays and MRI, may also be used to evaluate the severity of the injury and guide treatment 5, 6.
- Treatment for AC joint separations can range from conservative management, such as physical therapy and pain management, to surgical intervention, depending on the severity of the injury and the patient's overall health and activity level 2, 3, 5, 6.