What is a thumb ligament injury, or ‘Skiers Thumb?’
A sprained thumb occurs when the thumb ligaments are stretched beyond their capabilities, sometimes leading to a tear in the ligament. This is usually a result of excessive force bending the thumb backwards. It is a common sports injury, but we most typically see thumb strains when someone falls onto an outstretched hand.
In an acute injury, the thumb is pushed drastically away from the rest of the hand (while skiing, fall or during contact sport.)
In a chronic injury, a recurrent strain of this ligament leads to chronic rupture (gamekeeper’s thumb.)
Symptoms will differ based on the grade of the thumb sprain, however, here are the general symptoms to look out for if you believe you may have sprained your thumb:
- Pain and severe swelling on the inner part of the thumb immediately after the injury
- Pain and severe swelling on the base of the thumb immediately, or shortly after the injury
- Weakness and instability during grasp or writing
- Loss of motion when attempting to move the thumb circular
During clinical examination, the laxity of the ligament on the injured thumb will be compared to the non-injured thumb. The level of the ligament laxity indicates the degree of ligament injury.
Plain x-rays may show a small fracture, but are often normal.
Ultrasound scans and MRI scans can directly visualise and confirm whether the ligament has been injured.
Grades of Thumb Sprains
Thumb ligament injuries are categorised into three different grades based on the severity of the injury:
- Grade 1 (mild sprain) – The ligaments have been stretched, causing discomfort and swelling, however there is no tearing.
- Grade 2 (moderate sprain) – The ligaments have been extensively stretched, causing a partial tear. There may be some loss of function noticeable.
- Grade 3 (severe sprain) – The ligament has been forced back severely, causing a complete tear. This is a significant injury and requires medical, potentially surgical treatment.
The ligament injuries (ulna collateral ligament), where the ends of the ligament are still in contact or close proximity, treatment in plaster for 6-8 weeks will be required.
Majority of ulna collateral ligament injuries to the thumb are treated operatively. Once the ligament snaps one part of the torn ligament can flip onto the wrong side of a nearby tendon. This prevents the ligament ends from healing directly to each other.
The surgery is a day case procedure usually under general anaesthetic and takes about 30 minutes. A tourniquet is used; which is like a blood pressure cuff around the upper arm that prevents blood from obscuring the surgeons view. The ligament is repaired to its bony origin using a bone anchor. The repair is then protected by putting the thumb in a plaster.
Aftercare and follow up
Hand should be kept dry and clean until the wound has healed. One week after the procedure the plaster will be removed and a supportive splint will be applied by a hand therapist. Supervised motion will be started by the hand therapist at one week. Heavy activity or stress on the thumb joint is not allowed for 8 weeks.
Driving may not be possible for 6-8 weeks depending on which thumb is affected.
Time off work
Your return to work will depend on your job. Light manual workers can return to duty in 4-6 weeks. Heavy manual workers should not exert maximal grip for 8-12 weeks.
Risk of surgery
- Injury to superficial nerve, blood vessels and tendons
- Scar sensitivity (Scar desensitisation exercises after removal of stitches help to improve scar sensitivity however this can last up to 6 months after surgery)
- Further surgery (in event of recurrence or other complications)
- Future arthritis due to the initial injury
- Reduced grip strength
- CRPS (chronic pain syndrome: A small percentage of patients will develop a severe reaction after hand surgery, with lifelong permanent pain and stiffness which requires extensive physiotherapy and pain medication)
Scar desensitisation exercises
- Circular motion massages to the scar, from the palm moving towards the wrist using a simple moisturising cream. This must be carried out for 10 minutes, at least 3 times a day.
- Rubbing the scar on different textured materials to improve skin sensitivity.
- Submerging the hand under the cold and warm water to improve the temperature sensitivity.