The Anatomic And Clinical Study Of Skeletal Traction Of Humeral Epicondyle

Objective: The fracture of humerus is a common clinical injury. The fracture of proximal humerus is approximately 4%-5% of the fracture of all over the body, 45% of all humeral bone fracture. The fracture of shaft of humerus is 1.31% of all over the body. With the development of industry and traffic, high-energy lesion often leads to serious lacerating wound of soft tissue complicating splintered fracture of humeral bone, some GustiloⅡ,Ⅲ-type fracture of humerus is inadvisable to operate reduction onestage by internal fixation,it can not deploy mastic external fixation, external fixator and skeletal traction of olecranon process of ulna are better choice; the disturbance of the elbow joint motion exists in the orthodox skeletal traction of olecranon process of ulna. we find a kind of treated method to suit this type of the humeral fracture in the practice. The skeletal traction of humeral epicondyle is a neotype skeletal traction, it forms direct tensile strength through humeral traction, it outweighs skeletal traction of olecranon process of ulna. In our study, through the anatomic search and the measure of surrounding elbow joint, we will find the safe zone and angle of needling and withdrawing needle of the skeletal traction of humeral epicondyle to provide the study of reliable theory for afterward clinic generalization.Methods: 15 embalmed cadaver upper arms including elbow joint were observed. All of them were dissected in neutral position. The condylus medialis humeri and condylus lateralis humeri were chosen as anatomic landmarks. The test specimens were on the dissecting table. The specimens were cut in the center of distal medialis humeri, all of which were cut in the microtubule. The nervus cutaneus brachii lateralis and basilic vein were anatomized from superficial fascia to investigate their pathways,branches and distributions. After removal of superficial fascia, the suitable spatium intermusculare and points of Kirschner wire were determined basing on the anatomy of upperarm muscles and tendons and adjacent structure of humeral bone. In the same way, the specimens were cut in the center of distal lateralis humeri, the nervus cutaneus brachii lateralis and cephalic vein were anatomized from superficial fascia to investigate their pathways, branches and distributions. After removal of the superficial fascia, the suitable spatium intermusculare and points fixed screws were found based on the anatomy of upper arm muscles and tendons. Four mark points, including point A, the condylus medialis humeri; point B, the condylus lateralis humeri; point C, cubital nerve through medial brachial intermuscular septum;point D,radial nerve through lateral brachial intermuscular septum. It was the reference standard that from point A (the condylus medialis humeri) to point B (the condylus lateralis humeri), we dissected the intermusculare after cubital nerve through medial brachial intermuscular septum, and then we surveyed the relationship of AB-line and pathway of cubital nerve passing articulatio cubiti. In the same way, we dissected the intermusculare after radial nerve through lateral brachial intermuscular septum, and then we surveyed the relationship of AB-line and pathway of radial nerve passing articulatio cubiti.The safe placement and angle were determined with body surface marks. It was the principle that nerve, muscle tendon, blood vessel and elbow-joint motion should not be damaged.Results:1 The measurement of distal humerus. The length of shaft of humerus is (292.91±18.63)mm; the maximum diameter of mid-shaft of humerus is (19.95±2.16) mm; the minimum diameter of mid-shaft of humerus is (15.94±1.42)mm; the circumference of mid-shaft of humerus is (58.64±5.76)mm. The angle lean forward between distal humerus and long axis of shaft of humerus is 35.55°±6.58°. The width of distal humerus is (60.56±0.11) mm; the width of trochlea humeri and capitulum humeri is (45.96±0.21)mm; the sagittal diameter of trochlea humeri is (24.92±0.23)mm; the condylo-body angle between axis of shaft of humerus and inferior surface of trochlea humeri is 80.16°±0.13°. The front end diameter transversa of distal humerus is (22.67±2.46)mm; the inferior extremity diameter transversa of distal humerus is (24.58±2.56)mm; the posterior extremity diameter transversa of distal humerus is (24.83±2.51)mm. 2 The measurement of medial needling-point. The distance of from the point of cubital nerve through medial brachial intermuscular septum to condylus medialis humeri is (148.86+15.62)mm; the cubital nerve was dissected between caput mediale musculi tricipitis brachii and medial brachial intermuscular septum. Therefore medial needling-point was determined (32.65+5.26) mm upper supracondylar ridge of medial humerus.3 The measurement of lateral witherawing needling-point. The distance of from the point of radial nerve through lateral brachial intermuscular septum to condylus lateralis humeri is (99.58+11.82)mm; the radial nerve was dissected between brachioradial muscle, long radial extensor carpal muscle and brachial muscle. Therefore lateral witherawing needling point was determined (27.34+4.48)mm upper supracondylar ridge of lateral humerus.4 The measurement of needling angle. In the upperarm, the needling-direction was determined from medial to lateral of upper arm; it was vertical to axis of ordinate of humerus; the location of the upper arm was forward flexion 90°. In the same way, the location of the articulation of elbow was flexion 90°.Conclusion : Through the precision measurement and anatomic study of surrounding elbow joint, we find the safe placement and angle of the skeletal traction of upper condylus humeri, so we can avoid neurovascular injury. It provids the reliable theoretical basis for generalization on clinical.