A biomechanical study of pediatric flexor profundus tendon repair

OBJECTIVES To investigate the tensile strength of repaired flexor profundus tendons in young lambs, which would be equivalent to repairs in children older than 2 years of age. METHODS A comparative in-vitro experimental study conducted at King Saud University, Riyadh, Kingdom of Saudi Arabia from October 2014 to December 2015. We utilized 30 flexor profundus tendons of young lambs with a width of 4 mm. All tendons were repaired with a 4-strand repair technique using 4/0 polypropylene core sutures. In group I (n=10 tendons), 2 separate figure-of-eight sutures were applied. In group II (n=10 tendons), simple locking sutures were added to the corners of 2 separate figure-of-eight sutures. In group III (n=10 tendons), the locked cruciate repair was used. All tendon repairs were tested to single-cycle tensile failure. RESULTS There was no significant difference between groups II and III with regards to gap and breaking forces; and all forces of these 2 groups were significantly higher than the forces in group I. CONCLUSION It was concluded that 4 mm-wide pediatric flexor tendons allow a 4-strand repair and the use of 4/0 sutures. The use of locking sutures increases the tensile strength to values that may allow protective mobilization in children.