An Anatomic And Radiographic Measurement For Ribs And A Designing,Manufacturing,Biomechnical Measurement For Anatomic Plate Of Rib

Part one The anatomic and radiographic measurement for ribsObjective : To study the surgical zonation of thorax, the 6th ribs arepicked up for anatomic and radiographic measurement. The two methodswere compared with each other, to provid technical parameter fordeveloping anatomic plate of ribs.Methods: Six chest hygro-specimens (3 males and 3 females) wereused in the study. The general morphous, intercostal musle, vascular andnerve of thorax were observed. The thorax were divided into 3 zones byanterior axillary line and paravertebral line. The three zones wereAnterior Aera(AA), Lateral Aera(LA), Posterior Aera(PA). The 6th ribsare picked up for anatomic and radiographic measurement in whichfractures usually happened. The date need to measure include: transverserib length,width,thickness, frontal angle and horizontal angle oftransverse rib tubucle, costal tubercle length, rib costal tubercle angle, ribradian, fib length, rib width, rib thickness, cotication thickness, costalgroove width of each zone. The anterior and posterior rib reversal anglewere measured as well.Result: The whole thorax was a spatial structure. The intercostalsvascular and nerve courser in costal groove which disappear near theanterior axillary line. The rib length was 167.28±1.98mm, rib width was14.57±0.62mm, cortication thickness 4.54±0.16mm of lateral area wasthe largest in the 6th rib compared with other areas. The radian 133.14±3.61°and costal groove width 6.23±0.26mm of posterior area wasthe largest. The fib thickness 6.86±0.30mm of anterior aera was thelargest among all areas. The posterior fib reversal angle 24.14±0.49°waslarger than the other one. P＜0.05.The length, width and thickness oftransverse fib combination were 14.48±0.200mm, 11.60±0.35 mm,14.86±0.24 mm.The costal tubercle length was 15.02±0.32 mm. Thefrontal angle of transverse rib tubucle was 143.09±1.86°, the horizontalangle of transverse fib tubucle was 144.21±1.56°. The fib costal tubercleangle was 166.07±1.88°. There was no significient difference between CTmeasure and anatomic measure.Conclusion: (1) Through the study for zonation of thorax andanatomic and radiographic research for the 6th fibs, fib anatomic platecan be designed and manufactured based on measure result.It also playsground for the Study of other fibs.(2) There is no significient difference between CT measure andanatomic measure. Before operation, every parameter of ribs can bemeasuredby CT for surgeon.Part two The designing, manufacturing and biomechnicalmeasurement for rib anatomic plateObjective: To design and manufacture anatomic plate for every areaof the 6th fib, evaluate the biomechnical nature of plate, provide theory base for clinical application.Methods: Stainless steel was picked up for manufacturing commonanatomic and locking anatomic plate of each area. The 6th ribs of 8hygro-specimens(5 males and 3 famales) were used in to make fracturemodle. Every rib was cut into four 120mm-length parts: costovertebraljoint and posterior reversal angle section, lateral section, anterior sectionand anterior reversal angle section.Every section was made in to fracturemodel. Costovertebral joint and posterior reversal angle section fixedonly by anatomic plate. The other areas were fixed by four differentinternal fixation. Two hygro-specimens were fixed by common anatomicplate, two fixed by locking anatomic plate, two fixed by Kirschner wire,the other two fixed by reconstruction plate. Each section model abovewas test by non-destructive three point bent and twist. Anatomic plate forevery rib area was picked up to divide into two group, one group was testby destructive bent, another group was test by destructive twist.Result: The maximum bending and twisting intensity ofcostovertebral joint and posterior reversal angle anatomic plate were185.41±3.81N, 4.12±0.92Nm; which in anterior anatomic plate were217.40±3.55N, 3.47±0.11Nm; which in lateral anatomic plate a were200.69±4.14N, 3.76±0.47Nm, which in anterior reversal angle anatomicplate were 206.25±3.81N, 3.65±0.02Nm. The bending and twistingintensity of anatomic plate was superior to Kirschner wire, and inferior to reconstruction plate (P＜0.05). There was no significient differencebetween common anatomic plate and locking anatomic plate in bent andtwist intensity.Conclusion : (1) The intensity of common anatomic plate andlocking anatomic plate is superior to Kirschner wire, it can provide firmfixation for fractured fibs.(2) There is no significient difference between common anatomicplate and locking anatomic plate in bent and twist intensity. But the laterone can make operation more safely for its only permeating the outtercortex of ribs.