Hand CASE 16

CASE                               16                               

A 61-year-old, diabetic male presents with difficulty moving his dominant right index and middle fingers. He has noticed swelling and difficulty bending both fingers over the last 3 months. Occasionally when he wakes up in the morning, he finds that his fingers are stuck in the bent position. Running warm water over his fingers has helped them to open gradually.

The most likely diagnosis is:

1. Trigger fingers of the index and middle fingers

2. Multifocal small joint arthritis

3. Carpal tunnel syndrome

4. None of the above

 

Discussion

The correct answer is (A). This patient is a diabetic. Presentation of multiple trigger fingers is a well-described phenomenon in diabetics. While multiple trigger fingers can occur in any patient, this presentation appears to favor diabetics. Trigger finger presentation in diabetics, as much as in other populations, can vary from difficulty with generation of a composite fist, to swelling of the affected fingers, to involvement of multiple digits, to the classic form of triggering with clicking and popping with every act of flexion or getting stuck in the bent position.

The pathology in trigger fingers includes which of the following structures?

1. Volar plate of the MP joint

2. A1 pulley

3. Flexor tendon

4. Combination of B and C

5. A, B and C

 

Discussion

The correct answer is (D). Trigger fingers are a condition characterized by stenosing tenosynovitis at the level of the A1 pulley. Thickening of the A1 pulley, which is very well-documented especially in diabetics, is combined with

tenosynovial hypertrophy, which can be most marked at the level of the A1 pulley and just proximal to it. This discrepancy between the size of the A1 pulley, flexor tendons, and the tenosynovium which excurse within it is thought to be responsible for the phenomenon of triggering or catching.

The most appropriate treatment at this time would be which of the following?

1. Splinting at night

2. Splinting for 24 hours for 6 weeks

3. Local instillation of steroid preparations

4. Open release of A1 pulleys

5. Either C or D

 

Discussion

The correct answer is (E). Instillation of local steroid at the level of the A1 pulley is a treatment option which is successful in most patients including diabetics. However, there is data to show that the responses in diabetics are not as predictable as those in nondiabetics, the duration of relief after steroid injection is less compared to nondiabetics, and the response to steroid preparations as well as the recurrence of the symptoms appears to be related to the control of diabetes. There does not appear to be any convincing evidence to show a difference in response to steroids or the recurrence after steroid instillation in patients who have type 1 versus type 2 diabetes. At all times, when diabetics are injected with steroids at the level of A1 pulley as well as in other locations, they should be cautioned about a transient increase in blood sugar. This is all the more critical in patients who are type 1 diabetics as it may affect the insulin dosage. This transient increase in blood sugar usually lasts for less than 72 hours.

While instilling steroids at the level of the A1 pulley, the location of the A1 pulley is best described by which of the following techniques?

1. At the level of the digito-palmar flexion crease

2. At the level of a line joining the radial edge of the proximal palmar crease to the ulnar edge of a distal palmar crease or just distal to it

3. At the level of the distal palmar crease

4. At the level of the proximal palmar crease

5. None of the above

 

Discussion

The correct answer is (B). There are numerous methods described to identify the location of the A1 pulley. Among the choices offered in this, the most appropriate answer is B. The line joining the radial edge of the proximal palmar crease to the ulnar edge of the distal palmar crease is a skin representation of the location of the metacarpophalangeal joint. The A1 pulley overlies the volar aspect of the metacarpophalangeal joint. Therefore, it follows that this line would be a good representation of the approximate location of the A1 pulley. However, the A1 pulley is located a few millimeters distal to this line. Therefore, while instilling steroids one must remember that the A1 pulley is located slightly distal to this line, and while the needle may be introduced at the level of this line, it is directed distally at an angle of about 45 degrees so the steroid is placed at the approximate location of the proximal edge of the A1 pulley.

 

Objectives: Did you learn...?

 

Describe the pathophysiology of trigger finger?

 

 

Identify the clinical presentation of trigger finger in diabetics? Pinpoint various treatment options?