Shoulder Avascular Necrosis: Causes, Symptoms & Treatment
When persistent shoulder pain begins to limit your movement, it may be more than a simple strain. Avascular necrosis is a serious condition in which bone tissue in the shoulder begins to die due to loss of blood supply — recognising the early signs is essential for protecting the joint.
Understanding the Condition
What Is Avascular Necrosis of the Shoulder?
Avascular necrosis of the shoulder, also known as osteonecrosis, occurs when the humeral head — the ball portion of the shoulder’s ball-and-socket joint — loses its blood supply.
Bone is a living tissue that requires a steady flow of blood to stay healthy, repair itself, and maintain structural integrity. When this blood flow is interrupted, bone cells die. Over time, the weakened bone can collapse, destroying the smooth cartilage covering the joint and leading to severe osteoarthritis.
How the Shoulder’s Blood Supply Is Affected
The humeral head relies on a network of blood vessels to deliver oxygen and nutrients. Several factors can block or damage these vessels — physical trauma such as a fracture or dislocation can sever them directly, fat deposits can narrow them until blood can no longer pass through, and increased pressure within the bone itself can compress them, cutting off essential blood flow.
Recognising the Symptoms
Symptoms of shoulder avascular necrosis often develop gradually, progressing through distinct stages.
Early Signs
In the earliest stages, there may be no pain at all. As bone damage begins, the first sign is typically a mild ache that occurs only during movement — lifting the arm, reaching behind the back, or bearing weight on the joint. This early discomfort is frequently mistaken for a rotator cuff injury or muscle fatigue.
Progressive Symptoms
As the condition advances, pain becomes more constant — a deep, persistent ache present even at rest. Sleeping on the affected side becomes painful and often disrupts sleep. Everyday tasks such as getting dressed, brushing hair, or reaching for objects become increasingly difficult. A clicking or popping sound during arm movement may also develop.
Movement Restriction
When the bone begins to collapse, the joint surface becomes irregular, causing significant restriction in range of motion. Lifting the arm overhead or rotating the shoulder outward becomes difficult. At this stage, pain is often severe and has a considerable impact on daily life.
Risk Factors and Causes
Avascular necrosis can develop from several distinct causes, often related to anything that disrupts blood flow to the bone.
- —Steroid use — Prolonged use of high-dose corticosteroids such as prednisone can increase fat levels in the blood, blocking the small vessels that supply the bone.
- —Heavy alcohol consumption — Long-term heavy drinking causes fatty deposits to accumulate in blood vessels, restricting blood flow to the bone in a similar way.
- —Trauma — A severe shoulder dislocation or fracture of the humerus can tear or damage the blood vessels supplying the humeral head, sometimes triggering the condition months or years later.
- —Sickle cell anaemia — Abnormally shaped red blood cells can block small vessels, depriving bone tissue of oxygen.
- —Autoimmune disease — Conditions such as lupus can damage blood vessels and impair circulation to the bone.
- —Other systemic conditions — Gaucher’s disease, HIV infection, and the effects of radiation therapy or chemotherapy can all impair normal blood flow.
Getting a Diagnosis
Clinical Examination
Diagnosis begins with a thorough physical examination. An orthopaedic specialist will review your medical history — including previous injuries, underlying conditions, and current medications — before assessing range of motion, joint tenderness, and the specific movements that trigger pain.
Imaging
Because early-stage avascular necrosis may not produce visible changes on X-rays, advanced imaging is typically required.
- —X-rays — Useful in later stages to identify bone collapse or the development of arthritis.
- —MRI — The gold standard for diagnosis. An MRI can detect early changes in the bone marrow before they become visible on X-ray, allowing for earlier intervention.
Staging
Once diagnosed, the condition is assigned a stage based on imaging findings — from Stage I (early disease visible only on MRI) through to Stage IV (advanced bone collapse with severe arthritis). The stage directly informs the most appropriate treatment plan.
Treatment Options
Treatment depends on the stage of the disease and how much damage has occurred. Specialists typically begin with conservative measures and consider surgery only when those are insufficient.
Non-Surgical Management
- —Rest and activity modification — Avoiding heavy lifting and overhead activities to reduce stress on the joint.
- —Medications — NSAIDs to reduce pain and inflammation. Cholesterol-lowering medications or blood thinners may be prescribed in specific cases.
- —Physical therapy — Gentle exercises to maintain joint mobility and strengthen the muscles supporting the shoulder.
Surgical Treatment
- —Core decompression — Appropriate for early stages before bone collapse. The surgeon drills small channels into the humeral head to relieve internal pressure and encourage new blood vessel growth.
- —Shoulder replacement (arthroplasty) — When the bone has collapsed, joint replacement is typically the most effective option. The damaged bone and cartilage are replaced with artificial components — either a partial replacement (the ball only) or a total shoulder replacement.
Recovery and Rehabilitation
Recovery depends on the treatment received. Consistent physical therapy is essential in both pathways for restoring strength and range of motion.
When to See a Specialist
Schedule an evaluation with an orthopaedic specialist if you experience any of the following.
- —Persistent shoulder pain that does not improve with rest.
- —A history of high-dose steroid use, heavy alcohol consumption, or previous shoulder injury combined with new shoulder discomfort.
- —Pain that disrupts sleep or limits daily activities such as dressing or reaching.
- —Reduced range of motion, especially when lifting the arm overhead.
- —Clicking, popping, or grinding sensations during shoulder movement.
Frequently Asked Questions
Take the Next Step
Persistent shoulder pain should not be ignored, particularly when a progressive condition like osteonecrosis may be the cause. Early intervention is essential to preserving the joint and maintaining your quality of life.
