Dr. Kevin Yip

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

Featured on Channel NewsAsia

Thumb Ligament Injuries

Basics

Description
  • Thumb ligament injuries most commonly involve an incomplete or complete rupture of the UCL resulting from a forced radial deviation (abduction).
  • The RCL also can be injured, but it occurs less commonly.
  • Thumb ligament injuries occur in males and females of all ages.
  • Classification:
    • These injuries are complete or incomplete, based on the integrity of the ligament and its bony insertion.
  • Synonyms: Gamekeeper’s thumb; Skier’s thumb
General Prevention
Prevention involves knowing the mechanism associated with this injury.
Epidemiology
Incidence
These injuries occur most commonly in skiers and ball-handling athletes.
Risk Factors
  • Skiing accidents involving ski poles or falls
  • Athletic activities involving ball handling, such as baseball, football, or basketball
Etiology
Forced radial deviation (abduction) of the thumb is the cause.
Associated Conditions
  • Avulsion fracture of the tendon insertion
  • Capsular injuries or Stener lesions:
    • Complete rupture of the UCL with the adductor aponeurosis interposed between the distally avulsed ligament and its insertion into the base of the proximal phalanx
    • Important to recognize but not always readily apparent
Diagnosis
Signs and Symptoms
  • Pain
  • Swelling
  • Weakness
  • Deformity localized to the ulnar base of the thumb
  • Loss of pinch function
Physical Exam
  • Ulnar swelling, weakness, or a local palpable mass from a rolled avulsed ligament or bone fragment may be present.
  • The examiner often can radially deviate the patient’s thumb passively to a marked angle, as compared with the opposite, uninjured thumb.
    • Absence of an endpoint to joint opening is diagnostic.
    • Radiographs should be reviewed before testing for joint stability to assess for a fracture (so as not to displace a fracture if present).
  • Often a digital block is necessary to complete a full examination because of pain and swelling in the acute setting.
  • Surgical repair often is necessary in the presence of joint opening.
Tests
Imaging
  • Acute injuries:
    • Plain films are necessary to rule out fracture.
    • Stress testing usually is not needed.
  • Chronic injuries:
    • Radiographs should be obtained to assess for degenerative changes.
    • Stress radiographs may be helpful.
Pathological Findings
Attenuation or rupture of the UCL of the thumb is noted.
Differential Diagnosis
  • 1st metacarpal or proximal phalanx fractures
  • 1st CMC joint arthritis
  • Volar plate injury
Treatment
General Measures
  • A thumb spica splint or cast immobilization is indicated for 4 weeks for a partial rupture, or up to 6 weeks if an associated avulsion fracture is present (1).
  • For acute injury:
    • Rest, elevation, ice
    • Immobilization in a thumb spica splint
    • Analgesics
    • Orthopaedic follow-up
  • For chronic injury:
    • Thumb spica brace
    • Activity modification
    • Orthopaedic surgery consultation for elective ligament repair/reconstruction
Special Therapy
Physical Therapy
Physical therapy is helpful postoperatively to increase ROM and strength and to assist in resuming activities.
Medication
  • Commonly, proper rest is all that is needed for restoration of function, although pain and swelling may persist for several weeks.
Surgery
  • Surgical treatment in the acute setting is by suture repair.
  • For old injuries, tendon or fascial grafts may be necessary.
  • When crepitus or pain is present on a grinding type of joint manipulation (development of arthritis), arthrodesis (fusion) may provide the best result (check radiographs to diagnose arthritis).
  • If the ligament rupture is complete and acute, primary repair should be performed.
  • When the diagnosis is delayed for ≥1 month, fibrosis makes identification and repair of the ligament more difficult.

P.453


Follow-up
Prognosis
Generally, the prognosis is good.
Complications
  • Chronic instability
  • Nonunion of avulsed fragment
  • Degenerative joint disease
Patient Monitoring
  • Monitoring is performed by the orthopaedic surgeon to assess proper restoration of function and stability.
  • Patients are followed at 8-week intervals until healing is complete, with a full ROM and restoration of strength.
Miscellaneous
Codes
ICD9-CM
842.10 Thumb ligament sprain
Patient Teaching
Patients should limit activities with immobilization to allow for healing, followed by removable splinting as needed while activities are resumed slowly.
FAQ
Q: How is a partial UCL tear treated?
A: Incomplete tears of the UCL are managed with immobilization of the thumb metacarpal joint for 4 weeks in neutral varus/valgus alignment and slight flexion. It can be immobilized with an Orthoplast splint or a cast.
Q: How is the diagnosis of a complete UCL tear made?
A: Physical examination is usually adequate for diagnosis. The metacarpal joint is tested in 30° of flexion, and absence of an endpoint to joint opening with radial stress is key to the diagnosis. Plain radiographs should be obtained to assess for presence of an avulsion fracture, but avulsion fracture and complete tear of the UCL can occur in the same thumb.

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