ABSTRACT
<p><b>OBJECTIVE</b>To establish the three-dimensional finite element model of calcaneus, and to discuss mechanism of calcaneal fracture.</p><p><b>METHODS</b>The calcaneus of normal person was scanned with spinal CT, and the finite element model was established with the Sap 93 software. The node and element number of this model was 1 959 and 1 496 respectively. After establishing the finite element model of the calcaneus, the axial load of 500 N was applied on the model in neutral position and back stretches 20 degree position. The stress distribution and the displacement of the models were observed.</p><p><b>RESULTS</b>The fracture line passed through the lateral articular facet of talocalcaneal joint when the ankle joint was in neutral position, and the stress distribution was maximal at calcaneus from posteromedial to anterolateral aspect. In addition, the stress distribution was maximal from calcaneus to position between posterior talar articular surface and calcaneal tendon when the ankle joint was in back stretch position of 20 degree.</p><p><b>CONCLUSION</b>When falling down, the fracture line will pass through the facet of talocalcaneal joint from lateral to posteromedial side if the ankle joint was in neutral position; and the line will through pass the calcaneus body to post spinula joint, as well as avulsion fracture of calcaneal tendon occurred if the ankle joint was in back stretch position of 20 degree.</p>
Subject(s)
Adult , Humans , Male , Calcaneus , Diagnostic Imaging , Finite Element Analysis , Fractures, Bone , Diagnostic Imaging , Imaging, Three-Dimensional , Tomography, X-Ray ComputedABSTRACT
Objective To adopt a three-dimensional limited element analytic method to research into the cause and mechanism of the complications taking place after resection of head radius.Method To adopt a three-dimensional limited element analytic method to research into the stress transmission action of the head radi-us and the distribution alteration of the stress transmission after resection of head radius impacting on the stability of elbow and wrist.Result In normal cases,the stress value transmitted via head of radius takes 58% of the stress placed,36.85% via humeroulnar joint.The head of radius places a leading role in the stress transmission of the elbow joint.After rasection of the head of radius,the lateral of humeroulnar joint bears about 43% of the stress placed while the medial part bears about 21.6% of the stress.To compare with that before the resection of the head of radius the stress on the lateral is obviously increased more than the medial part.Conclusions The head of radius places a leading role in the stress transm ission of the el-bow joint.The resection of the head radius breaks the normal distribution of the stress on the elbow joint and produces great effect on the stability of the elbow joint and wrist joint.Therefore,in clinics we should pay great attention to the indication of rasection of the head of radius.
ABSTRACT
Objective To adopt a three-dimensional limited element analytic method to research into the cause and mechanism of the complications taking place after resection of head radius.Method To adopt a three-dimensional limited element analytic method to research into the stress transmission action of the head radi-us and the distribution alteration of the stress transmission after resection of head radius impacting on the stability of elbow and wrist.Result In normal cases,the stress value transmitted via head of radius takes 58% of the stress placed,36.85% via humeroulnar joint.The head of radius places a leading role in the stress transmission of the elbow joint.After rasection of the head of radius,the lateral of humeroulnar joint bears about 43% of the stress placed while the medial part bears about 21.6% of the stress.To compare with that before the resection of the head of radius the stress on the lateral is obviously increased more than the medial part.Conclusions The head of radius places a leading role in the stress transm ission of the el-bow joint.The resection of the head radius breaks the normal distribution of the stress on the elbow joint and produces great effect on the stability of the elbow joint and wrist joint.Therefore,in clinics we should pay great attention to the indication of rasection of the head of radius.