Ultrasound Quantitative Mechanical Evaluation Of Digital Flexor Tendons And Optimization Of Rehabilitation Programs

Study ?: Evaluation of the excursion and tension of flexor digitorum profundus tendon in different rehabilitation regimes Objective: In the 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)tendon 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 volunteers using three types of treatment protocols: modified Kleinert protocol,modified Duran protocol,and Belfast 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 the three protocols using one-way ANOVA analysis.Results: The excursion distance of FDP was 21.82±3.77 mm using the active finger flexion protocol,8.59±2.59 mm using the modified Duran protocol,and 12.26±2.71 mm 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(391.00±66.03Kpa).Conclusion: 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.Study ?: Effect of hand position on the tension and gliding efficiency of flexor digitorum profundus tendonObjective:Based on the Young's modulus(tension)of the flexor digitorum profundus(FDP)tendon of the middle finger during light clench exercise,the safety immobilized position of hand joints was screened.To explore the effects of different immobilized positions of the hand joints on Young's modulus(tension)and gliding efficiency of the FDP tendon.Methods: Sixty healthy volunteers were enrolled in our study,Shear wave elastography(SWE)was used to measure Young's modulus(tension)of the Flexor Digitorum Profundus(FDP)tendon during light clench exercise.We measured Young's modulus and gliding distance of FDP tendon in 15 immobilized splints respectively.Among those 15 immobilized position,the metacarpophalangeal(MP)joints position ranged from flexion 60 ° to 0 °,and wrist ranged from 50 ° flexion to 50 ° extension.Then,the comparison of FDP's Young's modulus between light clench and 15 immobilized position were performed respectively to screen out the safety immobilized positon.Results: The Young's modulus of FDP tendon in light clench was 346.72 ±121.02 k Pa.The Young's modulus was the lowest at 189.09 ±63.78 k Pa in wrist 50 °flexion and MP joints 60 ° flexion,and the highest at 415.76 ±123.23 k Pa in wrist 50 °extension and MP joints extension 0 ° position.There were ten safety immobilized positions,in which the Young's modulus was lower than that of light clench movement.The gliding distance of FDP tendon was more affected by wrist position.When the MP joints and wrist both were in neutral position,the gliding distance was longest(2.59cm);when the MP joints flexion 60 °and wrist flexion 50 °,the gliding distance was the shortest(0.91 cm);Among all ten safety positions,the longest gliding distance was 1.87 cm,while MP joints flexion 30°and wrist in neutral position.Conclusion: There were 10 safety immobilized positions,among which the tendon gliding efficiency was highest in MP joints flexion 30°and wrist in neutral position.This can be adopted to optimize flexor tendon protocol.Study ?:A compare investigation of optimized protocol and modified Duran protocol after flexor tendon repaired in zone ? Objective: The purpose of this study is to compare the treatment effect of optimized protocol(OP)and modified Duran protocol(MDP)after digital flexor tendon repaired in zone ?.Methods: From April to December in 2019,thirty-six patients after flexor tendon repair in zone ? were randomly divided into OP group(n = 18)and MDP group(n = 18).After 16 weeks rehabilitation intervention with accordingly treatment protocol,all patients were assessed with total acitve motion(TAM),grip strength(ratio),pinch strength(ratio),Strickland score,and DASH score.Results: The TAM of the affected fingers was measured(215.48?22.75)° in the OP group and(191.00?33.15)° in the MDP group(P <0.01).The grip strength ratio of the OP group was(78.33?19.63)%,which was significantly better than that of the MDP group(60.89?24.71)%,(P <0.05).According to Strickland score,the excellent rate of OP group was 100%,which was significantly higher than MDP group with 76.1%(P<0.05).There were no significant differences in pinch force and DASH assessment between these two groups.Conclusion The preliminary results show that the optimized protocol for repaired flexor tendon in zone ? is safe and regained better hand function,like TAM and grip strength.