Radial head micro-instability
Radial head micro-instability is a slight, abnormal play of the head of the radius at the elbow, caused by slack outer ligaments. It causes pain on the outer side of the elbow that looks like tennis elbow and often resists its treatment. Diagnosis is based on examination and imaging; when rehabilitation is not enough, an arthroscopy confirms the instability and tightens the ligaments.
What is radial head micro-instability?
At the elbow, the head of the radius rotates against the humerus when the forearm turns. It is held in place by a set of ligaments on the outer side of the elbow: the lateral collateral ligament and the annular ligament, which encircles the radial head.
When these ligaments are slack, the radial head remains stable enough for everyday life, but moves a little too much during certain movements. This abnormal play irritates the joint lining (synovitis), can wear the cartilage of the radial head and of the humeral condyle, and keeps the outer pain going. It is also called minor lateral elbow instability.
This slackness can follow an old sprain or a fall onto the hand, repeated strain, or repeated corticosteroid injections on the outer side of the elbow.
What are the symptoms?
- Pain on the outer side of the elbow, similar to tennis elbow
- Pain when rotating the forearm, especially palm up (supination), and when leaning on the hand
- Pain at the back and side of the elbow when straightening it
- Sometimes a clicking, snapping or catching sensation
- Pain that persists despite well-followed treatment for tennis elbow
How is it diagnosed?
- Clinical examination: the surgeon looks for precise tenderness over the joint between the radial head and the humerus, and for manoeuvres that reproduce the pain during rotation or weight-bearing
- X-rays: usually normal, they rule out another cause
- Ultrasound: it can measure the gap between the radial head and the humerus under load, which allows the instability to be quantified
- CT arthrogram (CT scan after injection of contrast dye into the joint): it looks for ligament slackness, cartilage wear or thickening of the joint lining
- Arthroscopy: it confirms the instability by directly showing the play of the radial head, and allows it to be treated at the same time
The surgeon also looks for compression of the posterior interosseous nerve, which can cause similar pain.
What are the non-surgical treatments?
- Rehabilitation with a hand therapist (physiotherapist), aimed at strengthening the muscles that stabilise the elbow
- Adapting your movements: temporarily limiting forceful rotation and weight-bearing on the hand
- Splint during painful phases
- Avoiding repeated corticosteroid injections, which can make the ligament slackness worse
When is surgery needed?
The operation is offered when pain persists and is troublesome despite several months of well-conducted treatment, and when examination and imaging point towards instability.
How is the operation performed?
The operation is done by elbow arthroscopy: a camera and fine instruments are inserted through small incisions. The surgeon confirms the instability, treats the synovitis and the folds of the joint lining (plica), then tightens the outer ligaments of the elbow with plication stitches (the slack ligaments are folded over and tightened on themselves). An associated tennis elbow can be treated at the same time.
The operation is done as a day case, under regional anaesthesia of the arm.
After the operation
- A resting splint protects the ligaments for 6 weeks
- Rehabilitation gradually restores movement, then strength
- Return to strenuous effort and sport is gradual, over several months
Complications are rare (stiffness, infection, nerve injury, complex regional pain syndrome) and are explained to you in consultation.
Frequently asked questions
Is it the same as tennis elbow?
No, but the two look alike and can occur together. Tennis elbow affects the tendons attached to the outer side of the elbow; micro-instability affects the ligaments and the inside of the joint.
Why did my injections not work?
An injection can calm inflammation but does not correct the ligament slackness; when repeated, corticosteroid injections can even make it worse.
Will my elbow dislocate?
No. This is a minor instability: the elbow stays in place, but the excessive play of the radial head keeps the pain going.
Consultations in Lyon
Dr Maxime Cievet-Bonfils sees patients at:
- ICMMS – Centre Eiffel, 18-20 rue Tronchet, 69006 Lyon (3rd floor)
- Clinique de l'Infirmerie Protestante, 3 chemin du Penthod, 69300 Caluire-et-Cuire (Building D, 4th floor)
Secretary (direct line): +33 4 87 25 83 35 · Consultations in French or English.
This page provides general information. It does not replace a consultation: every situation is different.