AC Joint Arthritis

AC joint arthritis is wear and tear of the small joint at the top of the shoulder, where the collarbone (clavicle) meets the acromion. It commonly causes pain directly over the joint, worse with reaching across the body, lifting, pressing movements and sleeping on the affected side.

At The New Foscote Hospital, you can access rapid consultant assessment, on-site MRI, ultrasound-guided injections, and—when needed—arthroscopic distal clavicle excision to relieve pain and restore function.

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Symptoms

• Localised tenderness on top of the shoulder (over the bony bump)
• Pain with cross-body movements (e.g. putting on a seatbelt, hugging)
• Discomfort during pressing/lifting or overhead activity
• Night pain when lying on the shoulder
• Clicking or a feeling of catching at the joint

Because other shoulder problems can co-exist, a specialist assessment is helpful to confirm the source of pain.

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Causes And Risk Factors

• Osteoarthritis from age-related cartilage wear
• Previous AC joint sprain/separation or repetitive overload (manual work, weights)
• Post-traumatic changes after fracture
• Overhead and pressing sports (weightlifting, rugby, tennis, swimming)

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Diagnosis At The New Foscote Hospital

Your shoulder specialist will take a focused history and examination, including cross-body adduction and AC joint compression tests. Investigations may include:

• X-ray to assess joint space narrowing and bone spurs
• MRI (on site) to evaluate AC joint inflammation and any coexisting conditions (rotator cuff, impingement, labrum)
• Diagnostic/therapeutic injection (local anaesthetic ± steroid) to confirm the joint as the pain source and provide relief

Orthopaedic Services
Meet Our Consultants
Imaging – MRI

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Treatment Options

Non-Surgical Care (first-line)

• Activity modification and technique change (reduce heavy pressing/overhead loads)
• Physiotherapy for shoulder mechanics, scapular control and graded loading
• Pain relief/anti-inflammatories if appropriate
• Ultrasound-guided corticosteroid injection into the AC joint for pain flares

Many patients improve with a structured combination of the above.

Surgical Treatment (for persistent symptoms)

• Arthroscopic Distal Clavicle Excision (Mumford procedure)
  • Day-case keyhole procedure removing a few millimetres of the clavicle end to stop painful bone-on-bone contact while preserving stability.
  • Often combined with treatment of associated problems (e.g. subacromial decompression) when indicated.
• AC Joint Stabilisation/Reconstruction
  • Considered if there is instability after previous separation alongside arthritis.

Your surgeon will discuss expected outcomes, risks and recovery timelines tailored to your shoulder and activity goals.

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Recovery And Rehabilitation

• Most patients go home the same day after arthroscopic surgery.
• Early movement is encouraged; a sling is used for comfort only.
• Physiotherapy focuses on range of motion, scapular control and progressive strength.
• Return to desk work: typically 1–2 weeks; manual work/weights: 6–12 weeks, guided by your surgeon and therapist.

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When To Seek Specialist Help

Book a consultation if you have:

• Top-of-shoulder pain that limits work, sport or sleep
• Pain with cross-body reach or pressing despite rest and physio
• Recurrent pain after a previous AC joint injury
• Suspected overlap with rotator cuff or impingement symptoms

Early assessment confirms the diagnosis and speeds recovery.