Ultrasonographic assessment in vivo of the excursion and tension of flexor digitorum profundus tendon on different rehabilitation protocols after tendon repair

Abstract Study design interpretive description study Purpose In management of patients with flexion tendon injuries, passive, control active and active motion protocols were proposed after repair to minimize tendon adhesion. The purpose of this study was to compare the excursion distance and the tension of Flexor Digitorum Profundus (FDP) during simulated active and passive motion using ultrasonography techniques using normal subjects. Methods Ultrasonographic assessment of FDP tendon of the middle finger was performed at the wrist level on twenty healthy college students using three types of treatment protocols: modified Kleinert protocol, modified Duran protocol, and active finger flexion protocol. The excursion distance was measured following the musculotendinous junction (MTJ) of FDP using the B mode ultrasound system. The elasticity of FDP tendon was measured using the shear wave elastography (SWE) technique. The excursion distance and the elasticity value were compared among three protocols using one-way ANOVA analysis. Results Twelve male and eight female students with mean age of 22.6±1.8 years were invited to join the study. The excursion distance of FDP was 21.82±3.77 mm using the active finger flexion protocol, 8.59±2.59mm using the modified Duran protocol, and 12.26±2.71mm using the modified Kleinert protocol. The elasticity was significantly higher in extension position when compared to passive flexion positions, but found lower than active flexion position. Discussion The active finger protocol was found to require strongest tension of the tendon and with longest excursion. There was similar tension generated using both passive motion protocols. The modified Duran protocol appeared to create less excursion upon movements than the modified Kleinert approach using the objective ultrasonic evaluation. It is suggested that if the surgical repair was strong and without any complications, the active flexion protocol might work best to regain tension excursion. However, if there are complex problems involved, then the Kleinert approach or Duran approach would be chosen.