Cadaveric investigation of active finger range of motion for detection of intratendinous needle placement

Background: The authors' purpose was to determine if investigators can predict whether a needle is within a finger's flexor tendon by postinsertion tactile and visualization evaluation in an active range-of-motion cadaver model. Methods: In 48 cadaver fingers, a 25-gauge needle, with a 1-cc syringe attached, was placed into one of three randomly assigned positions at the A2 pulley level: within the flexor digitorum profundus, within the flexor digitorum superficialis, or outside both flexors and the sheath. Each finger was cycled through full active range of motion as three hand surgeons, blinded to each other's responses and needle position, recorded whether they thought the needle was intratendinous. The initial investigator confirmed needle position after each surgeon's assessment. Results: Active cadaver finger range of motion did not allow surgeons to accurately determine whether a needle was in a flexor tendon. There was no statistically significant agreement among the surgeons about whether the needle was intratendinous. Conclusion: Because of poor interobserver agreement, sensitivity, and negative predictive value, we conclude that finger range of motion is not a reliable test to detect intratendinous needle placement in this cadaver model.