A Novel Cadaveric Model of the Quadriga Effect

INTRODUCTION: The quadriga phenomenon results from excessive shortening of the flexor digitorum profundus (FDP) tendon to the middle, ring, or small finger. METHODS: Five cadaveric specimens were used to create a model for quadriga. The FDP tendons to the middle, ring, and small fingers were shortened in 5-mm increments, and the tip-to-palm (TTP) distance of adjacent fingers was recorded. RESULTS: Shortening of the middle finger FDP by 10 mm resulted in an average TTP distance of 6 mm in the ring finger and 5 mm in the small finger. Shortening the ring finger FDP by 10 mm produced an average TTP distance of 11 mm in the middle finger and 9 mm in the small finger. Shortening of the small finger FDP by 10 mm resulted in an average TTP distance of 14 mm in the middle finger and 10 mm in the ring finger. DISCUSSION: Shortening the FDP by as little as 10 mm produced a significant quadriga effect, which was more pronounced with shortening of the small and ring FDP tendons compared to the middle finger.