Angle Setting Of Thumb Pulp In Thumb Reconstruction And Its Effect Of Biomechanics

Objective: The thumb is the most important digit in the human hand,itusually listed as40%of total hand usefulness,and is essential in grasp andpinch. When part or all of the thumb is lost post-trauma, disease,or absenceinborn and the amputated tissue is not replantable, various degrees offunctional impairment occur.Its essential to reconstruction the thumb torecover the configuration and function. The development of thumbreconstruction in many ways parallels the overall history of technical advancesin hand surgery.At present, Many techniques have been advanced toreconstruct the thumb,for Cocked Hat, Metacarpal Lengthening, OsteoplasticReconstruction, Toe Transfer and Pollicization of Injured Digit et al.Best of allare Second Toe Transfer and Wrap-Around Flap.But in clinical,patient did notuse the hand after thumb reconstruction and made it meanless.One of thefactor which effect the configuration and function is the angle of the thumb,which depended the thumb pulp to the other fingers.When thumb pinch withthe other fingers,angle of thumb dependent the direction and the acreage.Itwould effect the configuration and function of the thumb when the angle isproper or not.We will observe and analyse the acreage and pinchstrength of thumb and the other fingers in nomal and setting angles,provide thebest angle for thumb reconsruction.Method: There are7fresh specimens in the study.break the thumb inproximal segment,and survey pinch-strength of thumb-to-fingers when thumbin normal angle and5°,10°,15°pronation and5°,10°,15°supination whenpulling of2Kg,4Kg and6Kg by electronic pinch-strength gauge,and statisticand analys the data. Survey acreages of thumb-to-fingers when thumb innormal angle and5°,10°,15°pronation and5°,10°,15°supination when pulling of4Kg by Pressure Sensitive Films and statistic and analys the data.Result: Using ANOVA method with SPSS13.0software,there is nochanges of thumb-to-fingers pinch-strength when thumb b in normal angle and5°,10°,15°pronation and5°,10°,15°supination in thumb-to-indexfinger,thumb-to-middle finger and thumb-to-ring finger, acreages ofthumb-to-fingers is partial defferet,there is no meaning when thumb in normalangle and5°,10°pronation and5°supination in thumb-to-index finger,andacreages changed when angles exceeding, there is no meaning when thumb innormal angle and5°,10°,15°pronation and5°,10°supination inthumb-to-middle finger and thumb-to-ring finger, acreages decrease whenthumb15°supination.Conclusion: There is no difference of thumb-to-finger pinch-strengthwhen thumb in nomal angle, pronation or supination to the data and statisticalresult,and some changes to acreages of thumb-to-fingers.The exact result is noacreage change of thumb-to-index finger when thumb in in normal angle and5°,10°pronation and5°supination, acreage decrease when angles exceeding,no acreage change of thumb-to-middle finger and thumb-to-ring finger whenthumb in normal angle and5°,10°,15°pronation and5°,10°supination,acreage decrease when thumb15°supination.