Updated: 1/17/2020

Trigger Finger

Topic
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Questions
5
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Evidence
10
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Videos
3
Techniques
1
https://upload.orthobullets.com/topic/6027/images/trigger finger.jpg
https://upload.orthobullets.com/topic/6027/images/finger_pulleys_2.jpg
Introduction
  • Description
    • Trigger finger (trigger thumb when involving the thumb) is the inhibition of smooth tendon gliding due to mechanical impingement at the level of the A1 pulley
      • symptoms are usually progressive and include pain, clicking, catching, and locking of the digit in flexion
      • may present as congenital trigger thumb 
  • Epidemiology
    • 2-3% of general population
    • more common in diabetics 
    • more common in females older than 50
    • ring and long fingers are most commonly involved in adults
  • Mechanism
    • caused by stenosing tenosynovitis at the A1 pulley 
    • fibrocartilaginous metaplasia of tendon and/or pulley
      • proliferation of chondrocytes
      • increased type III collagen
      • occasional pathologic nodule of the flexor digitorum profundus tendon
        • flexor digitorum superficialis often unaffected
    • trigger thumb may have a fourth pulley (variable annular pulley) causing stenosis in up to 75% of patients
  • Associated conditions
    • diabetes mellitus
    • rheumatoid arthritis
    • amyloidosis
    • hypothyroidism
    • sarcoidosis
    • gout 
    • pseudogout
    • calcific tendinitis
    • septic tenosynovitis
    • carpal tunnel syndrome
      • >60% of patients with trigger digits have clinical or electrodiagnostic evidence of carpal tunnel syndrome
Anatomy
  • Flexor pulleys of finger 
    • A1 pulleys overlie the MP joints
  • Muscles
    • FDP 
    • FDS 
Classification
 
Green Classification
Grade I Palm pain and tenderness at A-1 pulley
Grade II Catching of digit
Grade III Locking of digit, passively correctable
Grade IV Fixed, locked digit
 
Imaging
  • Radiographs
    • not required in diagnosis or treatment
Presentation
  • Symptoms
    • usually progressive
    • pain at the level of the A1 pulley
    • clicking
    • catching
    • finger becoming "locked" in flexed position at the proximal interphalangeal (PIP) joint
    • may have referred pain to dorsal MCP/PIP region
  • Physical exam
    • tenderness at level of A1 pulley 
    • triggering with digit flexion and extension
    • palpable nodule of the flexor tendon 
    • fixed flexion of PIP joint
Treatment
  • Nonoperative
    • night splinting, activity modification, NSAIDS
      • indications
        • first line of treatment
    • corticosteroid injections
      • indications
        • best initial treatment for fingers, not for thumb
      • technique
        • give 1 to 3 injections in flexor tendon sheath
        • diabetics are less likely to obtain relief of symptoms
      • improvement in up to 60% of patients
  • Operative
    • surgical debridement and release of the A-1 pulley
      • indications
        •  in cases that fail nonoperative treatment
      • open or percutaneous technique
        • open releases is standard operative management with high success rates
      • satisfactory results achieved in >90% of cases
    • release of A1 pulley and 1 slip of FDS (usually ulnar slip)  
      • indications
        • persistent/recurrent triggering after A1 pulley release
        • rheumatoid arthritis patients may benefit from FDS slip excision without A1 pulley release
          • sparing of A1 pulley may prevent exacerbation of ulnar drift at the MCP joint
        • pediatric trigger finger 
          • presents with Notta's node (proximal to A1 pulley), flexion contracture and triggering
          • surgical treatment at 2-4 years of age to prevent interphalangeal joint contracture
          • may need to release remaining FDS slip and A3 pulley 
Techniques
  • Open release of the A-1 pulley
    • approach
      • longitudinal, transverse, or oblique incision
    • technique
      • local anesthetic allows intraoperative assessment of triggering to confirm adequate release
      • slip of FDS released if persistent triggering
    •  
      • in addition to A-1 pulley, may also need to release
        • tight band of superficial aponeurosis proximal to A1 pulley (A0 pulley)
        • one or both limbs of the sublimus tendon
        • additional pulleys including A-3
    • postoperative
      • early passive and active ROM 4 times a day
      • if the patient does not have FROM at first post-op visit then send to PT
  • Percutaneous release
    • techniques vary
    • typically 18-19g needle with bevel oriented parallel to the tendon
      • needle advanced longitudinally using tactile feedback 
      • withdraw the needle and attempt to elicit triggering to ensure adequate release


Complications
  • Radial digital nerve injury 
    • at risk due to superficial location
  • bowstringing
  • wound dehiscence
  • scar tenderness
  • stiffness
  • tendon scoring (percutaneous technique)
 

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Technique Guides (1)
Questions (5)
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(OBQ11.56) A 2-year-old child has a flexion deformity of the interphalangeal joint of his thumb as seen in Figure A. Surgical correction of this deformity places what structure most at risk as it crosses the surgical field? Review Topic

QID: 3479
FIGURES:
1

Princeps pollicis artery

6%

(187/3003)

2

Ulnar digital nerve

9%

(280/3003)

3

Oblique pulley

7%

(223/3003)

4

Ulnar digital artery

2%

(65/3003)

5

Radial digital nerve

74%

(2234/3003)

L 2

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(OBQ10.113) When surgically treating a trigger finger in a child, what structure may need to be released in addition to the A-1 pulley? Review Topic

QID: 3207
1

One or both limbs of the sublimis tendon

69%

(2547/3665)

2

A-4 pulley

5%

(199/3665)

3

Lumbrical origin

6%

(208/3665)

4

Dorsal interosseous insertion

2%

(61/3665)

5

Anomalous insertion of the MCP joint collateral ligament

17%

(627/3665)

L 3

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(OBQ05.164) A 64-year-old diabetic female presents with sudden catching and locking of her ring finger when trying to extend it. Attempts at finger extension are painful, and she notes tenderness in her distal palm. A clinical photo is shown in Figure A. Which of the following structures are implicated in the pathogenesis of this condition? Review Topic

QID: 1050
FIGURES:
1

Extensor digitorum tendon

1%

(26/3634)

2

Grayson's ligament

2%

(69/3634)

3

Oblique retinacular ligament

1%

(38/3634)

4

A1 pulley

96%

(3474/3634)

5

Transverse carpal ligament

0%

(8/3634)

L 1

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SUBMIT RESPONSE 4
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