Preoperative And Postoperative Plantar Biomechanical Analysis Of Patients Undergoing Greattoe-to-thumb Transfer

Objective: With the development and application of microsurgical technique,the studies on great toe-to-thumb transfer become more prevalent, the function and appearance of transferred thumb become more ideal,but the influence on donated foot has been a controversial issue. At present there are reports on plantar biomechanical analysis of patients undergoing the second toe-to-thumb transfer, but few on great toe-to-thumb transfer.By plantar biomechanical analysis,we can acquire physiological and pathological mechanics and function parameters under sports and all posture,these parameters can be more accurate and overall to reflect the dynamic changes about the plantar impulse, center of gravity and stress,so plantar biomechanical analysis is a more important method to know the dynamic chage of donated foot.Above all,from September,2005 to June,2007 we hve tested 15 patients'pre and post opratiaonal plantar biomechanical parameters who have undergone the great toe-to-thumb transfer by the plantar biomechanical machine made by Belgium Footscan Company.To test and analysis parameters , we can reveal the change of the donate foot between preoperation and postoperation and provide clinical theory basement.Methods: From September,2005 to June,2007,we hve taken 15 great toe-to-thumb transfer operations on patients whose thumbs wereⅡ°damaged.Of these 15 patients three are 9 male,6women and 4 left,11 right.Age is 17y to 36y (average 23.1 years);Fellow up:1moths to 6 months.Height: 156cm～175cm(average 167. 4cm);Weight: 50kg～70kg (average 161.3kg);Foot length: 23cm～26cm(average 24.3cm).Of all these operations,thumb proximal phalanxes were reserved and plantar cuts were primary healed.Testing 15 patients'pre and post opratiaonal plantar biomechanical parameters who have undergone the great toe-to-thumb transfer by the plantar biomechanical machine made by Belgium Footscan Company.Patients walks naturally on the testing plate barefootedly(gait speed: 95～117 step / min).Patients walks 3⁴ times on the plate just like usual with no pain,the Footscan system machines can obtain the parameters and analysis the parameters.Because many factors may affect the plantar press such as walk style,on shoes,foot shape and gait speed,we tests the same foot preopretion and postoperation(1 moth,3months and 6 moths respectively) by self-contrasted.Results: 1 month after operation:the maximum pressure of M₁～M₃ reduced while M₄,M₅ increased;The impulse of M₃ reduced while M₄,M₅,H_L increased;The contact period of FFPOP reduced while the contact period of ICP,FFP,M₄,M₅,H_M,H_L increased;The value of x increased negatively, during the period of FFP FFPOP, the lateral foot pressure increased. 3 month after operation: the maximum pressure of M1 reduced while M5 increased; The impulse of M₄,HL increased; The contact period of ICP increased while the contact period of FFPOP reduce. 6 month after operation: the maximum pressure of M3 increased..Conclusions: 1 After great toe-to-thumb transfer operation 1 moths,because the pain of surgical cut,the lateral and post foot pressure increases insteadly.2 After operation 3 moths the pressure under the graet toe is obviously less than nomal,but the pressure under the fifth head of metatarsal bone increases.3 After operation 6 moths the donate plantar biomechanical parameters tends to be nomal.