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Acromioclavicular (AC) joint injections serve both diagnostic and therapeutic purposes in managing shoulder pain. Diagnostically, an injection that alleviates pain confirms the AC joint as the pain source, while persistent pain post-injection suggests alternative origins. Therapeutically, AC joint injections are indicated for conditions such as osteoarthritis, inflammatory arthritis, and persistent pain due to joint degeneration or impingement. These injections are particularly beneficial for individuals whose activities exacerbate shoulder pain, including athletes and laborers, as they can enhance function and facilitate a return to activity when conservative treatments are insufficient. This educational activity provides healthcare professionals with a comprehensive understanding of AC joint pathology, covering indications, contraindications, and a detailed, step-by-step guide to performing safe joint injections. The activity emphasizes the use of corticosteroid injections to reduce inflammation and provide temporary relief, while underscoring the importance of integrating these injections into a broader rehabilitation program. The course highlights the critical role of interprofessional collaboration among orthopedic surgeons, physical therapists, radiologists, nurses, and primary care clinicians in developing comprehensive care plans. By fostering effective teamwork, healthcare providers can ensure optimal patient outcomes in managing AC joint disorders Objectives: Identify appropriate indications for acromioclavicular joint injections based on patient history, clinical examination, and imaging findings. Evaluate evidence-based techniques for preparing and performing acromioclavicular joint injections. Assess potential risks and complications of acromioclavicular joint injections. Collaborate with an interprofessional team to promote the appropriate and safe use of injections in managing patients with acromioclavicular joint pathology. Access free multiple choice questions on this topic.

Acromioclavicular joint pathology is a common cause of shoulder pain, particularly in athletes and individuals who perform repetitive overhead activities. The acromioclavicular joint is a synovial joint at the acromion process of the scapula and the clavicle (see Image. Acromioclavicular Joint Injection). The acromioclavicular joint is designed with limited mobility but significant load-bearing responsibility, especially during arm elevation. The etiology of acromioclavicular joint pathology is often multifactorial, stemming from degenerative changes, inflammatory processes, repetitive mechanical stress, or traumatic injury.[1][2] Degenerative changes common to the acromioclavicular joint due to osteoarthritis include joint space narrowing, cartilage wear, and osteophyte formation. Inflammatory arthritis, including rheumatoid arthritis, may also affect the acromioclavicular joint. Repetitive mechanical stress can also cause bony or soft tissue injury and degeneration. Acute trauma to the acromioclavicular joint can cause bony or ligamentous injuries. Acromioclavicular sprains can result in a hypermobile and unstable acromioclavicular joint, increasing the likelihood of developing arthritic changes. Acromioclavicular joint injections serve diagnostic and therapeutic purposes in managing acromioclavicular joint pain. Diagnostic injections involve administering an anesthetic, where pain relief confirms the source of the pain. Diagnostic injections can be used in presurgical evaluations to identify candidates for procedures such as distal clavicle excision.[3] Therapeutically, corticosteroid, hyaluronic acid, or platelet-rich plasma injections are used to reduce pain and improve function.[4] These injections are especially valuable for patients who have not responded adequately to conservative treatments such as physical therapy, nonsteroidal anti-inflammatory drugs, or activity modification. Hyaluronic acid and platelet-rich plasma injections have shown questionable benefits in knee osteoarthritis, and there is a lack of high-quality studies supporting their use for AC joint osteoarthritis.[5]

Acromioclavicular joint injections serve diagnostic and therapeutic purposes in managing acromioclavicular joint pain. Diagnostic injections involve administering an anesthetic, where pain relief confirms the source of the pain. Diagnostic injections can be used in presurgical evaluations to identify candidates for procedures such as distal clavicle excision.[3] Therapeutically, corticosteroid, hyaluronic acid, or platelet-rich plasma injections are used to reduce pain and improve function.[4] These injections are especially valuable for patients who have not responded adequately to conservative treatments such as physical therapy, nonsteroidal anti-inflammatory drugs, or activity modification. Hyaluronic acid and platelet-rich plasma injections have shown questionable benefits in knee osteoarthritis, and there is a lack of high-quality studies supporting their use for AC joint osteoarthritis.[5] Results of acromioclavicular injection can vary depending on the pathology and injection composition. Corticosteroid injections often provide significant pain relief, though the effect is typically temporary, lasting from weeks to months.[6][7][8] Corticosteroid injections are appropriate for patients seeking short-term relief, such as athletes aiming to return to activity or to enable more efficient progress in rehabilitation programs designed to restore shoulder mobility and strength. Therapeutic injections can be repeated as necessary; however, evidence indicates diminishing effectiveness with frequent use, particularly in cases of advanced joint degeneration.[4] Various techniques are used to administer acromioclavicular joint injections. Conventional landmark-guided injections rely on palpating anatomical landmarks for injection site location. Landmark-guided injections are commonly used due to their simplicity and minimal resource requirements. Unfortunately, this method often results in medication being delivered outside the joint space due to improper injection site identification.

Various techniques are used to administer acromioclavicular joint injections. Conventional landmark-guided injections rely on palpating anatomical landmarks for injection site location. Landmark-guided injections are commonly used due to their simplicity and minimal resource requirements. Unfortunately, this method often results in medication being delivered outside the joint space due to improper injection site identification. Imaging-guided techniques such as fluoroscopy and ultrasound can be used with superior precision.[9][10] Ultrasound guidance is increasingly preferred to fluoroscopy as it is noninvasive, costs less, and enables improved outcomes due to the real-time visualization of needle placement. Study results have shown that ultrasound-guided injections improve accuracy rates significantly and reduce the risk of procedural complications.[11] Additionally, ultrasound guidance reduces patient discomfort, as the clinician can more confidently and precisely deliver the injection to the target area.[12] Outcomes improve when injections are integrated with comprehensive rehabilitation programs rather than as a standalone treatment.[13] As with other interventions, patient selection, accurate delivery, and integrating injections within a broader management plan are critical to achieving optimal outcomes.

Although rare, possible complications of acromioclavicular joint injections include: Infection Bleeding or hematoma formation Allergic reaction Post injection pain Joint degradation Tendon or ligament damage Neurovascular injury Complications associated with corticosteroid injections include: Skin and soft tissue atrophy Hypopigmentation Tendon weakening or rupture Joint cartilage damage Elevated blood glucose levels (especially in patients with diabetes) Systemic effects such as facial flushing, mood changes, insomnia, and increased blood pressure Complications associated with hyaluronic acid injections include: Joint effusion Skin reactions Stiffness or decreased range of motion Synovitis Systemic reactions such as headaches or nausea Infection or foreign body reaction Complications associated with PRP injections include: Calcification within the injected tissue Joint effusion

The interprofessional team ensures patient safety and optimizes outcomes during acromioclavicular joint injections. Advanced clinicians take the lead in diagnosing acromioclavicular joint pathology, selecting suitable candidates for injection, and performing the procedure, often with imaging guidance for precision. Nurses support by ensuring patient comfort, preparing the injection site with sterile techniques to prevent infection, and educating patients on post-procedure care and monitoring for adverse effects. Pharmacists review medications for potential contraindications, such as anticoagulants or allergies, and guide appropriate corticosteroid dosing to minimize systemic risks. Physical therapists contribute by designing rehabilitation programs to reduce pain, enhance shoulder range of motion, and restore functional strength, fostering long-term shoulder health. This collaborative approach, paired with comprehensive patient education and close monitoring, maximizes the therapeutic benefits of acromioclavicular joint injections while minimizing risks and complications.