Avulsion of the ulnar collateral ligament of the base of the thumb
Cause
Usually results from sudden hyper-abduction/extension injury to the thumb either from a fall or tackle situation, when wrapped around a ski pole.
Diagnosis
Pain is felt on the inside/ulna side of the base of the thumb. There is weakness with pinch grip
Examination shows an opening up of the joint with a radial stress.
X-rays can show subluxation or opening up of the joint, or a small bony avulsion fragment
An MRI scan can help determine the extent of the ligament tear.
Treatment
Grade I and II tears can be treated non-operatively with the use of plasters and splints
Grade III tears require surgical intervention to reattach the ligament to the base of the thumb, as it is usually sitting above the adductor aponeurosis (Stennar Lesion)
Surgery is done under general anaesthetic and the ligaments reattached to the bone using a bone anchor
Chronic tears greater than three months, often require reconstruction using spare tendon of the forearm
Potential Complications
Infection, Haematoma, neurovascular injury
Stiffness to the MCP joint
Ongoing pain in the joint
Post Op Care
Patient will awake from surgery in a thumb spica slab
Seen at 10 days for removal of sutures and to go into a thermoplastic splint or thumb spica cast for a total of six weeks
A strengthening programme for six weeks to three months under the care of the hand therapist.
Specialist review at 10 days and six weeks, and three months.
