Finger Collateral Ligament Tear on ultrasound: Imaging Findings
Finger collateral ligaments stabilize each side of the small finger joints. A side-bend injury can stretch, partially tear, or completely tear the ligament, sometimes with a tiny avulsion fragment. X-rays evaluate alignment and bone injury. MRI or ultrasound can clarify soft-tissue disruption when instability or persistent pain remains.
Common Symptoms
- Side-to-side finger pain after the joint is forced sideways
- Localized tenderness on the radial or ulnar side of a PIP, DIP, or MCP joint
- Swelling, bruising, or stiffness after a ball strike or twisting injury
- Feeling of instability when pinching or gripping with the affected finger
What We Look For on Imaging
- Radial or ulnar collateral ligament thickening, edema, or discontinuity
- Avulsion fragment at the ligament attachment site
- Joint widening, subluxation, or asymmetric alignment on stress or standard views
- Bone bruise near the injured side of the joint
- Associated volar plate, central slip, or pulley injury
Frequently Asked Questions
Can a collateral ligament tear have a normal X-ray?
Yes. X-rays may be normal when the ligament tears without pulling off a bone fragment. Persistent side tenderness or looseness on exam can lead a clinician to use MRI or ultrasound to assess the ligament directly.
How is a finger collateral ligament tear different from a thumb UCL tear?
The thumb UCL has special importance for pinch stability and can form a Stener lesion. Collateral ligament tears in the other fingers are still important, but management depends on the joint, stability, fragment size, and functional demands.
Sources
- Lapegue F, André A, Lafourcade F, et al. Finger sprains, ultrasound anatomy, and pathology of finger ligaments. Semin Musculoskelet Radiol. 2024;28(6):694-707.
- Lourie GM, Gaston RG, Freeland AE. Collateral ligament injuries of the metacarpophalangeal joints of the fingers. Hand Clin. 2006;22(3):357-364, viii.
- Gaston RG, Lourie GM. Radial collateral ligament injury of the index metacarpophalangeal joint: an underreported but important injury. J Hand Surg Am. 2006;31(8):1355-1361.
- Prucz RB, Friedrich JB. Finger joint injuries. Clin Sports Med. 2015;34(1):99-116.
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