New technique for producing uniform partial lacerations of tendons.

Previous experimental studies of partial flexor tendon lacerations have used tendons cut by hand with magnification and a scalpel. When we biomechanically tested chicken flexor tendons lacerated by hand through 75% of their cross-sectional area, the tensile strength of the residual tendons varied substantially among specimens from different chickens as well as between digit matched pairs of tendons from the same animal. A device was designed that uses standard scalpel blades to create a uniform tendon laceration by leaving a constant area of tendon intact regardless of original tendon size or shape. With the instrument we have called the "tenotome," a second group of chicken flexor tendons were lacerated through 75% of their cross-sectional area. Biomechanical testing of the tendons cut with the tenotome showed significantly less variation when compared with the tendons cut by hand. Use of the tenotome permits the establishment of a more uniform model for partial flexor tendon injuries, and potentially decreases the number of specimens needed to demonstrate statistical significance.