Dr Terry Hammond
MBBS FRACS Orth
The simplest, cheapest and most important investigation for a shoulder problem is a plain x-ray. There are a number of conditions best visualised by this modality. Osteoarthritis is surprisingly common and a plain x-ray usually provides the diagnosis. It is also very useful in cases of massive irreparable rotator cuff tears. In this condition the humeral head subluxes superiorly and may even erode the acromion. If this appearance is seen on a plain x-ray it not only confirms the diagnosis but also confirms that the tear is both longstanding and irreparable. Plain x-rays also show degenerative conditions of the AC joint and can also show a large spur under the acromion which may erode the rotator cuff. X-rays are very important in cases of significant trauma. Fractures (such as a fracture of the greater tuberosity) are often undiagnosed unless an x-ray is performed.
Ultrasounds have long been used in the diagnosis of shoulder problems. They are relatively cheap and non-invasive. However, they are inaccurate unless performed by a experienced musculo-skeletal sonographer. They probably have a role in screening for a full thickness rotator cuff tear but even then they are often inaccurate. They have a very limited role in investigations of young patients with shoulder problems.
Magnetic resonance scans are now the gold standard for shoulder investigation. They are extremely accurate in diagnosing rotator cuff problems and also show the size of a tear and whether it is repairable. Magnetic resonance scans are useful for labral tears which are significant in younger patients, particularly those with recurrent instability. An arthrogram is required in patients who have a suspected labral tear. MRI scans are particularly useful in serious conditions such as malignancy.
I have developed a protocol for magnetic resonance scanning which I have found particularly useful in diagnosing shoulder problems. If you are referring a patient my office staff would be happy to arrange scans using this protocol.
The best investigation for a shoulder problem is a plain x-ray. Ultrasound is probably only useful to screen for a full thickness cuff tear in an older patient. MRI scanning, often with an arthrogram, is the gold standard.