KEMBLE WANG - Upper Limb & Trauma Surgeon
MBBS (Hons), FRACS, FAOrthA
Trigger finger/thumb release
(developed in conjunction with Melbourne Hand Therapy)
The tendons of the fingers and thumb glide through a protective covering called the tendon sheath. The sheath is like a tunnel, and it is lined with a thin membrane called synovium. This synovial lining produces lubricating fluid that helps reduce friction as the tendons glide through the tendon sheath.
Areas of thick fibrous tissue called “pulleys” are part of the tendon sheath. These “pulleys” are attached to the bones of the fingers and thumb and hold the tendons close to the bones over which they pass. There are different types of pulleys on the palm side of the hand. The annular pulley (A1) is located on the palm side of your hand just below your big knuckle. It is this pulley that is commonly affected in the case of a trigger thumb/finger.
A trigger thumb/finger is caused by the thickening of the synovial sheath surrounding the tendons or a narrowing of the first (A1) pulley. The tendon can become stuck and unable to slide through the tunnel. Or, the finger can catch or lock when making a fist. It is like a knot on a shoelace which can get stuck on either side of the shoelace hole. This can occur when the finger is either straight or bent and sometimes it catches but does not quite completely stick.
Trigger finger can affect anyone, and it is a very common condition. The following groups have a slightly higher risk of developing the condition.
-
People aged 40 – 60 years;
-
Paediatric trigger digits is another group. This typically affects the thumb and often occurs in both hands;
-
People who have had a previous hand injury;
-
People with rheumatoid or osteoarthritis;
-
People with diabetes;
-
Repeated strain due to work or hobby activities.
Treatment options;
-
Rest / splinting can be effective in the early stages. This helps to prevent the tendon catching through the pulley;
-
Cortisone injections into the tendon sheath are sometimes used in adults;
-
Surgery.
Surgery:
The object of surgery is to widen the tunnel so the tendon can slide more easily. During surgery, a small incision is made into the palm of the hand. The first (A1) pulley is released and this relieves the constriction of the tendon as it passes through the sheath. It is often necessary to remove the thickened synovial covering surrounding the tendon. In paediatric trigger thumbs, an abnormal tendon strip may also have to be removed.
Post-operative rehabilitation
0 – 1 week:
-
The incision will be closed with sutures and a bulky dressing applied. This will need to stay dry. Patients will not be completely immobilised. In fact, patients are encouraged to move their fingers gently back and forth within the limits of the bandage. This helps the tendon to glide.
-
It is a good idea for patients to elevate their hands in the first three days post-surgery to reduce swelling.
-
Generally, post-operative pain is minimal and can be managed with paracetamol.
-
However, patients cannot lift anything heavy with the injured hand for about four weeks after surgery. This ensures adequate healing. It is also important to avoid strong, forceful gripping.
1 week:
-
The post-operative dressing is removed, and a low-profile tape applied over the incision.
-
At this point, patients can be advised that typing on a keyboard and activities that do not require a forceful grip or extension can be resumed. The hand can be used for light activities.
-
Encourage patients to make a full fist. If it is difficult to complete a fist, the other hand can be used to assist (as per the picture below). It is also helpful for patients to try and fully straighten their finger or thumb. But do not force this action if it is difficult. The goal is to get the finger straight but not forced backwards. It is important the wound remains closed.
-
For toddlers: at this stage all dressings will be removed, and it is safe for the wound to get wet. Until dressing is removed, parents should try to keep the hand clean and dry (which can be challenging!)
2 weeks-4 weeks:
-
It is useful to continue to tape over the incision for the first 3 weeks.
-
Generally speaking, patients should be able to resume driving, as long as they can make a full, comfortable fist.
-
At three weeks it is useful to start gently massaging the scar with any non-perfumed moisturiser.
4-6 weeks:
-
If patients are continuing to struggle to extend their finger, they can be encouraged to put their hands flat on the table to try and force the finger straight. Occasionally, a splint may be made for overnight use only. This will apply a gentle stretch to regain the full extension.
-
At this stage, patients can increase the use of their hands and resume day-to-day task as long as it feels comfortable.
-
At the 5-6 weeks mark, patients may find that the scar is starting to harden and become a little tender. This is a normal as the scar tissue begins to mature. Massage is useful to help soften the scar and reduce tenderness. The scar tissue should not be covered or protected with any additional dressing or padding at this stage.
Return to activity / sports:
-
By six weeks, patients should be able to return to all normal sporting activities.