What Happened?
A cyclist presented to our clinic after falling hard during a trail ride on his mountain bike. He was overall OK but reported sharp pain in his 5th metacarpal joint (little finger) only with deep flexion/bending of the finger. So we're thinking it's not an obvious fracture or dislocation, which would typically be a lot more painful. To get a dynamic look at the structure, we used musculoskeletal ultrasound.
What Did Musculoskeletal Ultrasound Show
What Are We Looking At?
We're looking at a long axis, dynamic view of the 5th metacarpal joint. The top image is the injured finger, the bottom is a healthy finger. Notice the hypoechoic (dark) shadow over the top image that isn't present in the healthy image? Also, the very small hyperechoic (bright white) structure on the top image when the finger goes into flexion that again isn't present on the bottom healthy image?
My Thoughts?
This dynamic view most likely shows ligament damage with a potential avulsion fracture. I advised this patient to consult with a hand specialist to get another opinion and probable x-ray. Best case scenario is that he has to immobilize the finger to allow healing and can resume training ASAP.
Dr. Kyle Bowling is a sports chiropractor based in Louisville, Ky. His practice is one of few sports injury clinics in Louisville to offer musculoskeletal (MSK) ultrasound. Reach out anytime with questions!