Can clinical examination cause a Stener lesion in patients with skier's thumb?: a cadaveric study

Approximately one-third of all injuries of the upper limb and 7% of all injuries in skiing affect the ulnar collateral ligaments of the thumb metacarpophalangeal joint (skier's thumb). In some patients the collateral ligaments are displaced proximally over the adductor aponeurosis, resulting in a so-called Stener lesion. In these cases surgical treatment is indicated. We hypothesized that a Stener lesion could be provoked by clinical stability testing in patients with a skiers thumb and performed a cadaveric study on 10 Thiel fixated cadaver hands. For clinical stability testing, the thumb was manually deviated in radial direction in both 30° flexion and extension of the MP-joint. It was performed with maximum strength by two hand surgeons after sequential detachment of the ulnar collateral ligaments. After every sequence, it was assessed if the clinical stability testing had caused a Stener lesion. All of the 10 cadavers showed identical results while testing the clinical stability. A decreased stability was only found after cutting both parts of the ulnar collateral ligaments. A Stener lesion could not be provoked in any of the cadavers at any time by clinical stability testing. Summarizing our findings we conclude that a proper performed clinical stability testing of the thumb MP joint is a safe maneuver, which does not lead to a Stener lesion in patients with skier's thumb.