Radsource radiologists are constantly communicating and sharing knowledge with each other. In our blog series Today’s Interesting Case, our team will post notable cases and images for discussion from time to time.
Today’s case involves a 39 year-old male who presented 2 months after injuring his little finger playing basketball with pain along the unar aspect of the finger and no relief with rest, ice, and NSAIDs. The surgeon suspects an injury to the radial collateral ligament of the metacarpophalangeal joint.
STIR coronal images were obtained at the metacarpophalangeal joint of the little finger. The image on the left obtained through the midportion of the thumb metacarpophalangeal joint demonstrates a normal low signal ulnar collateral ligament (white asterisk). In contrast, the radial collateral ligament is absent and replaced by hyperintense signal (red asterisk). The sagittal band is well seen since it is outlined by edema (arrowhead). The image on the right is more dorsally located and demonstrates the radial collateral ligament at the metacarpal origin but with the torn end of the ligament oriented proximally and radially (arrow), located proximal to the radial sagittal band (arrowhead).
Axial STIR images at the level of the little finger metacarpal head confirm the findings. The left image demonstrates the normal ulnar collateral ligament (white asterisk), edema instead of the ulnar collateral ligament (red asterisk), and the intact radial sagittal band (arrowheads). The right image obtained proximal to the left demonstrates the dorsally and radially folded radial collateral ligament which remains attached at the metacarpal head.
Stener lesions are a well know entity resulting from a valgus force of the abducted thumb causing a distal tear of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb and displacement proximal to the adductor aponeurosis, resulting in a non-reducible ligament tear. Much rarer is an analogous injury at the fifth metacarpophalangeal joint caused by hyperabduction of the metacarpophalangeal joint resulting in a distal tear of the radial collateral ligament with displacement of the ligament proximal to the radial sagittal band. As discussed in this letter published in the Journal of Hand Surgery, this injury has been termed a “Stener-like” lesion and like a true Stener lesion requires surgical repair.