Definition of trigger finger :
Trigger finger, whose medical name is stenosing tenosynovitis of the flexors is one of the most frequent tendon pathologies in hand surgery.Trigger finger can affect the longer fingers, but also the thumb, in which case the term trigger thumb is used.
Trigger finger, is a conflict between the flexor tendons and the first pulley of the finger; this conflict induces inflammation of the synovial sheath around the tendon. This synovial thickening called synovitis (stenosing) causes finger pain but also loss of fluidity in the flexion-extension motion of the finger and a triggering effect.
Video of ultrasound-assisted trigger finger release surgery
Diagnosis of trigger finger :
Trigger finger is a form of finger tendonitis with pain in the finger that is often more acute in the morning when waking up; so trigger finger may manifest itself only in the morning and be followed by discomfort during the day.
Trigger finger , is more likely in people suffering from diabetes and can be associated with a characteristic hand deformity called diabetic cheiroarthropathy.
Further investigations are seldom necessary. If in doubt a sonogram of the finger that can be performed at the hand surgeon's office will confirm a thickening of the digital tunnel's first pulley, or even a synovial reaction or the presence of fluid in the digital sheath.
Ultrasound-assisted trigger finger release procedure :
In the absence of diabetes and if the trigger finger has been evolving for less than 3 months, the first line treatment consists in slow-release corticosteroid injections in the digital sheath.In many cases, these injections can cure this finger tendonitis.
When injections in the trigger finger have been ineffective, or when the patient is diabetic, a simple hand surgery procedure can be performed. Here, I am discussing an ultrasound-assisted trigger finger release technique. This ultrasound-assisted procedure makes it possible to treat the trigger finger surgically through a single 2-mm incision in the metacarpophalangeal flexion crease.
The ultrasound-assisted procedure is performed in about 7-8 minutes with the finger under anaesthesia. The finger can move and be used immediately after the hand surgery procedure, the finger's dressing can be removed after 2 days. The trigger effect disappears immediately after the procedure.
The patient is in the dorsal decubitus position, the first stage of the hand surgery consists in positioning the ultrasoundprobe over the MCP joint and locating the proximal limit of pulley A1 and the MCP joint.
The sonographic diagnosis thus becomes systematic before the procedure on the finger , allowing possible - rare - differential diagnoses to be made: a synovial cyst, a giant cell tumor, or an effusion in the MCP joint contributing to tendon impingement.
A surgical incision is then carried out using a 18G (1-mm) needle at the proximal flexion crease of the MCP.
The second stage of the surgical procedure consists in inserting a 1.8-mm bespoke scalpel blade.
The blade and the section of the pulleyseront will be under constant sonographic control. Indeed, for this ultrasound-guided procedure a continuous In-Plane approach is used, with the blunt tip of the blade inserted under pulley A1 and sectioning carried out from distal to proximal to the edge of pulley A1. In addition to sonographic feedback, a distinctive squeaking noise can be heard when pulley A1 is sectioned.
When triggering was constant, the patient is able to see for himself/herself during the procedure that catching and popping have disappeared.
Once the pulley is sectioned, an ultrasound-guided injection is performed proximally so as to limit inflammation induced by healing.
This type of ultrasound-assisted procedure can also be performed in cases of de Quervain's wrist tendonitis.
Recovery after ultrasound-assisted trigger finger release surger :
A dressing is applied to the palm of the hand and the finger, and must be kept for 2 days. The hand can be used immediately after surgery for all daily gestures, including driving.
After 2 days, the dressingwill be removed and the patient can use his/her finger normally for all activities, including self care.
Triggering disappears immediately but a few weeks will be needed to recover full range of motion. For several months resistive movements will cause pain in the finger. The hand is restored to its full strength 3 to 4 months after surgery. However in 10% of cases, pain may persist for several months and require an injection of slow-release corticosteroids.
In some cases, this ultrasound-assisted trigger finger surgery can be associated with carpal tunnel surgery.