Flexor Tendon Injuries Hand

Other Names

• Flexor tendon laceration

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Background

• Classified anatomically into zones
• Relatively rare

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Pathophysiology

The map of left-hand tendon lacerations isolated for each finger. The figure on the left shows the numbers of patients who had flexor tendon injuries according to flexor tendon zones. The figure on the right shows the numbers of patients who had extensor tendon injuries according to extensor tendon zones. Each finger was painted in its own color.

• Typically volar laceration-type trauma
• Frequently involve neurovascular injuries
• At risk Anatomy:
  • Flexor Digitorum Superficialis
  • Flexor Digitorum Profundus
  • Flexor Carpi Radialis
  • Flexor Carpi Ulnaris
  • Flexor Pollicis Longus

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Risk Factors

• Unknown

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Differential Diagnosis

Differential Diagnosis Finger & Hand

• Fractures
  • Phalanx Fractures of the Hand
  • Metacarpal Fractures
    • Boxers Fracture
    • Rolando Fracture
    • Bennett Fracture
• Dislocations
  • Metacarpophalangeal Joint Dislocation
  • Interphalangeal Joint Dislocation (Proximal and Distal)
  • Carpometacarpal Joint Dislocation
• Tendinopathies
  • Extensor Tendon Injuries of the Hand
  • Central Slip Extensor Tendon Injury
  • Flexor Tendon Injuries of the Hand
  • Boutonniere Deformity
  • Swan Neck Deformity
  • Jersey Finger
  • Mallet Finger
  • Trigger Finger
  • De Quervains Tenosynovitis
  • Volar Plate Avulsion Injury
  • Sagittal Band Injury
  • Mannerfelt Lesion (FPL Rupture)
• Ligament Injuries
  • Gamekeepers Thumb (UCL)
  • Radial Collateral Ligament of the Thumb Injury (RCL)
• Neuropathies
  • Wartenbergs Syndrome
  • Carpal Tunnel Syndrome
  • Guyon Canal Syndrome
• Arthropathies
  • Carpometacarpal Arthritis
  • Finger Arthritis
  • Rheumatoid Arthritis
• Nail Bed Injuries
  • Nail Bed Lacerations
  • Nail Bed Avulsions
  • Subungual Hematoma
  • Paronychia
  • Felon
• Pediatric Considerations
  • Proximal Phalanx Avulsion Fracture (Thumb)
  • Middle and Distal Phalanx Avulsion Fracture
• Other
  • Dupuytrens Contracture
  • Intrinsic Plus

Differential Diagnosis Wrist

• Fractures
  • Distal Radius Fracture
    • Bartons Fracture
    • Chauffers Fracture
    • Colles Fracture
    • Die-Punch Fracture
    • Radial Styloid Fracture
    • Smiths Fracture
  • Distal Ulna Fracture
  • Carpal Fractures
    • Scaphoid Fracture
    • Lunate Fracture
    • Triquetrum Fracture
    • Pisiform Fracture
    • Trapezium Fracture
    • Trapezoid Fracture
    • Capitate Fracture
    • Hamate Fracture
  • Essex Lopresti Fracture
• Dislocations
  • Wrist Dislocation (Radiocarpal and/or Ulnocarpal)
  • Carpometacarpal Joint Dislocation
  • Distal Radioulnar Joint Dislocation
  • Lunate Dislocation
  • Perilunate Dislocation
• Instability & Degenerative
  • Scapholunate Instability
  • Lunotriquetral Instability
  • Scaphoid Nonunion Advanced Collapse
  • Distal Radial Ulnar Joint Instability
  • Kienbocks Disease
  • Dorsal Wrist Impingement
  • Carpal Instability
• Tendinopathies & Ligaments
  • De Quervain's Tenosynovitis
  • Intersection Syndrome
  • TFCC Injury
  • Wrist Tendinopathies
  • Extensor Carpi Ulnaris Tendinopathy
• Neuropathies
  • Carpal Tunnel Syndrome
  • Pronator Teres Syndrome
  • Anterior Interosseus Nerve Syndrome
  • Posterior Interosseus Nerve Syndrome
  • Guyon Canal Syndrome
  • Wartenbergs Syndrome
• Pediatric Considerations
  • Distal Radial Epiphysitis (Gymnast's Wrist)
  • Torus Fracture
• Arthropathies
  • Wrist Osteoarthritis
  • Scaphotrapeziotrapezoidal Joint Arthritis (STT Arthritis)
  • Rheumatoid Arthritis
  • Gout
• Cartilage
  • Osteochondral Defect
• Vascular
  • Hypothenar Hammer Syndrome
• Other
  • Ganglion Cyst of Wrist
  • Ulnar Impingement Syndrome
  • Infectious Tenosynovitis

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Clinical Features

Normal distal forearm squeeze test

History

• Universally present with loss of flexion distal to the lesion

Physical Exam: Physical Examination Hand

• Cascade Sign can be used to help evaluate for rotational deformity
• Range of motion: Passive and active evaluation
• Neurovascular injury

Special Tests

• Distal Forearm Squeeze Test: Squeezing the distal forearm should flex the fingers with intact tendons

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Evaluation

• Standard Radiographs Hand
• Ultrasound can be helpful to assess suspected lacerations

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Classification

• Flexor tendon injuries are divided into zones
• Zone 1
  • Distribution: Distal to insertion of FDS
  • Pathology: Jersey Finger
• Zone 2
  • Distribution: FDS insertion to A1 pulley
  • Pathology: Can injury both FDS and FDP
• Zone 3
  • Distribution: A1 pulley to distal carpal ligamnt
  • Pathology: Often associated with neurovascular injury
• Zone 4
  • Distribution: Carpal Tunnel
  • Pathology:
• Zone 5
  • Distribution: Carpal tunnel to forearm
  • Pathology: Often associated with neurovascular injury
• Thumb
  • T1
  • T2
  • T3

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Management

Nonoperative

• Flexion important for function, high risk of morbidity
• Nonoperative management essentially limited to partial lacerations < 60% of tendon width

Operative

• Flexor tendon repair
• Flexor tendon reconstruction
• FDS transfer to thumb

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Return to Play

• Needs to be updated

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Complications

• Tendon adhesions
• Rerupture
• Joint contracture
• Swan Neck Deformity
• Trigger Finger

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See Also

• Hand and Wrist Anatomy (Main)
• Finger Pain (Main)
• Hand Pain (Main)
• Wrist Pain (Main)

External

• Sports Med Review Hand Pain: https://www.sportsmedreview.com/by-joint/hand/

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