The Stability Analysis Of The Active Extreme Posture Of Male Normal Wrist Joint

Objectives The aim is to investigate the factors and give some images for diagnosis and treatment of the carpal instability,by measuring the angles between some major carpal bones of normal men wrist at the extreme posture.Methods 30 healthy volunteers(60 wrists hibaterally) were recruited as the normal group;30 patients that seeking outpatient service in the hospital with a history of wrist joint trauma or pain from 2013 to 2015 were organized as patient group.X-ray scans was used to take X-ray images for the two groups' wrist,following the standard scaning method. And to calculate the carpal height ratio(CHR),they took X-ray PA images in the extreme active ulnar,radial deviations(EAUD,EARD) and neatral position;And then they take lateral images in the extreme active flexion,extension deviations(EAFD,EAED) and neatral position to measure scapholunate angle(SLA),radiolunate angle(RLA) and capitolunate angle(CLA).The normal ranges of the four indexes are based on the statistics above,and then we analyses the statistics of the patients.Results 1.The normal ranges calculated:in the EAFD positon:SLA:50.08°~75.04°,CLA: 0.39°~45.9°,RLA: 25.72°~38.97°; in the EAED positon:SLA:29.17°~43.31°,CLA:-51.57°~-25.62°, RLA:-32.55°~-12.81°;CHR:in the EARD position: 0.481~0.584;in the EAUD position: 0.492 ~ 0.588. 2.Patient group:11 cases were abnormal in the extreme position images:2 of them were abnormal in RLA,4 in SLA,3 in CLA and 2 in CHR.Conclusions 1.All indexes change significantly in the extreme position,compared with neutral position,and the motion scope between corresponding carpal bones is large.Following that,the corresponding ligaments become tensive.2.In terms of the patients with symptoms in the functional position but their X-ray images are negative,they need extreme position X-ray images and then the instability of their wrist are more likely to be found.