ABSTRACT
Objective To study the anatomic and biomechanical characteristics of the dorsal radial ligament and anterior oblique ligament in carpometacarpal (CPC) joints of the thumb,so as to provide references for ligament repair.Methods Forty fresh hand specimens of adult male cadavers were dissected to make specimen of trapezium bone-ligament-the first metacarpal bone,of which 20 cases retained the dorsal radial ligament and 20 cases retained the anterior oblique ligament,respectively.The ligaments were tested on biomechanical testing machine,and their length,width,thickness,the maximum load,elastic modulus and elongation rate were measured and calculated.Results For the dorsal radial ligament and anterior oblique ligament,their maximum load was (213.5 ±72.4) and (168.7 ±35.2) N,their elastic modulus was (17.2 ±6.7) and (9.3 ±2.5) MPa,their elongation rate was (116.2 ± 21.3) ％ and (92.7 ± 22.4) ％,respectively.The maximum load,elastic modulus and elongation of the dorsal radial ligament were larger than those of the anterior oblique ligament.Conclusions For the capsular ligament in CPC joints of the thumb,the dorsal radial ligament has a higher stiffness and stronger toughness,which plays an important role in maintaining stability of the joint.The anterior obligue ligament is easy to be damaged due to its smaller stiffness and poor toughness.The anterior oblique ligament is suggested to be reconstructed firstly to treat arthritis of CMC joints,and materials whose elastic modulus and elongation rate are similar with the dorsal radial ligament should be selected.
ABSTRACT
BACKGROUND:Researchers suggest that thermal damage happens when the temperature of biological tissues is over 44℃. Accurate analysis of burn range wil facilitate diagnosis and therapy of skin burns. OBJECTIVE: To establish the mathematical model of the skin tissues subjected to high temperature and to analyze heat transfer process, and then to predict the burn range of the skin. METHODS:A finite element method was used to simulate the temperature field when the skin tissue was burned. And the relevant animal experiment was conducted to identify the mathematical model. RESULTS AND CONCLUSION:The temperature field was obtained by using the finite element method and the variation tendency between the theoretical data and the experimental data were agreed, but they did not fuly coincide. The scope of skin burn can be predicted by the present finite element method, and help to research the process of heat transfer.
ABSTRACT
Objectiye To explore the diagnostic and therapeutic methods of anastomotic leakage after low anterior resection of rectal cancer. Methods The clinical data of 16 cases with anastomotic leakage after sphincter saving operation which was performed through anterior resection for patients with lower rectal cancer were retrospectively analyzed. Results Among the 186 cases of low anterior resection of rectal cancer,16 cases occurred anastomotic leakage,incidence rate was 8.6% ;14 cases healed through local douche and drainage; 1 case healed by emergency operation and upper colostomy after bacterial peritonitis;only one elderly patient died for infectious shock. Conclusion Anastomotic leakage was the severe complication of low anterior resection,and timely correct treatment and doing well safety precautionary measures before operation could reduce the incidence rate of anastomotic leakage.