Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Flexor Tendon Laceration

Basics
Description
  • Flexor tendon laceration may require emergency surgical repair, depending on:
    • Location of the laceration
    • Hand dominance
    • Age and occupation of the patient
  • Lacerations located between the distal transverse palmar crease and the PIP joint flexor crease represent an area of increased risk from scarring or adhesions and poor functional outcome resulting from the complex and precise anatomy in this area (no-man’s land).
  • The superficial and deep flexors are at risk at different locations in the hand because each has a superficial course on the palmar surface.
  • Each tendon adds to the strength and independent function of the fingers in flexion.
  • Classification is by the name of the tendon lacerated (superficial versus deep) and the location of the laceration.
  • The level of the laceration is described most easily by the zone of the injury.
    • Zone 1: Fingertip to PIP flexor crease
    • Zone 2: PIP flexor crease to distal palmar transverse crease
    • Zone 3: Distal palmar transverse crease to distal wrist flexor crease
Epidemiology
Incidence
This injury is one of the most common types of tendon lacerations.
 
Risk Factors
Working with sharp objects
 
Etiology
The cause of the injury is sharp laceration to the tendon (e.g., via knife, glass).
 
Associated Conditions
  • Digital nerve laceration
  • Digital artery laceration
Diagnosis
Signs and Symptoms
  • Laceration to the palmar aspect of the hand
  • Change in the resting posture of the finger relative to the other fingers (e.g., slight extension of the injured finger)
  • Loss of independent flexion of the distal digital joint when tested
  • Loss of ability to flex the finger
  • Decreased strength of finger flexion
  • Evidence of tendon injury during wound exploration
  • Evidence of tendon sheath or pulley laceration during wound exploration
Physical Exam
  • Test independent DIP and PIP flexor flexion.
  • Test for lacerations of adjacent nerves.
  • Test the strength of each finger.
  • Explore the wound for a tendon or pulley injury.
Tests
Imaging
Obtain radiographs to rule out foreign body, fracture, dislocation, or avulsion injury.
 
Differential Diagnosis
  • Fracture-dislocation
  • Avulsion injury of tendon
  • Rupture of tendon
Treatment
General Measures
  • Tetanus shot
  • Wound washout using normal saline
  • Antibiotics (usually 3rd-generation cephalosporin IV)
  • Elevation and splinting of the hand until surgical evaluation is performed
  • Orthopaedic consultation and preoperative laboratory tests
  • Digital nerve and artery laceration:
    • Careful and complete neurovascular examination, including 2-point discrimination and Doppler study of the neurovascular bundle on each side of the tendon in question
Special Therapy
Physical Therapy
  • Postoperative ROM depends on the lesion location and the type and quality of repair.
  • Usually, the goal is passive ROM as soon as the skin repair tolerates motion.
    • Children and adults who cannot follow restrictions should be immobilized postoperatively.
Medication
Antibiotic choice may be related to the contamination at the time of injury.
 
Surgery
  • Flexor tendon repair and results depend on the location, level, and type of injury.
  • Primary acute repair has provided the most functional results.
  • Repair should be performed within 1-2 weeks after injury.
  • In the presence of a flexor tendon sheath injury, early repair may be done to minimize scarring and adhesions and to give the best functional result.
Follow-up
Prognosis
  • Prognosis depends heavily on the type and location of the injury.
  • Injuries located between the distal transverse palmar crease and the most distal digit flexor crease often result in finger stiffness.
  • In other areas, results are better.
Complications
  • Infection
  • Decreased ROM secondary to scarring or adhesions
  • Loss of strength
  • Need for delayed repair or reconstruction
  • Tendon rupture
Miscellaneous
Codes
ICD9-CM
840.9 Upper limb tendon laceration
 
Patient Teaching
  • The patient should understand the severity of the injury even though the laceration may appear small.
  • Functional outcome strongly depends on the compliance and cooperation of the patient.
  • Postoperative hand therapy is critical to a good result.
Prevention
United States Occupational Safety and Health Administration guidelines should be used when working with sharp objects.
 
FAQ
Q: Do partial flexor tendon lacerations need to be repaired?
A: If the laceration involves >60% of the tendon, repair is recommended. If it involves <60% of the tendon, repair is not necessary and debridement is indicated only for entrapment of the tendon under the pulley system (e.g., triggering).
 
Q: What are the timing requirements for flexor tendon repair?
A: Repair should be performed in the operating room within 3 weeks, optimally in <2 weeks, of the laceration. Primary repair usually is not recommended in presentations delayed >5-6 weeks.

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